This invention relates to a colorant composition comprising a layered clay material intercalated with at least one cationic colorant, optical brightener or a mixture thereof. This invention also relates to a polymer-clay nanocomposite comprising (i) a melt-processible matrix polymer, and (ii) a layered clay material intercalated with at least one cationic colorant, optical brightener or a mixture thereof, wherein the clay-cation colorant/optical brightener intercalate is incorporated into the matrix polymer. The invention further relates to articles produced from the polymer nanocomposite.

This invention relates generally to a colorant composition and a polymer-clay nanocomposite having improved color and appearance comprising a colorant composition. This invention further relates to articles produced from the polymer-clay nanocomposite.
There is much interest in polymer/clay nanocomposites because of the improved properties exhibited by the nanocomposites. For example, U.S. Pat. No. 4,739,007 discloses polyamide/clay nanocomposite materials containing clays intercalated with alkylammonium salts. Polymer/clay nanocomposites typically suffer from poor color and appearance due to the presence of the clay.
One objective of this invention is to provide clays intercalated with colorants and/or optical brighteners that mask the color of the clay and provide polymer/clay nanocomposites that are colorless, white, or slightly colored. It is also an object of this invention to provide clays intercalated with colorants that provide colored polymer/clay nanocomposites.
Colorants or pigments derived from the reaction of a cationic dye and a clay are known. For example, R. Fahn and K. Fenderl, Clay Minerals, 18, 447-458 (1987) disclose pigments derived from montmorillonite clay intercalated with certain cationic dyes. However, incorporation of the pigments into thermoplastic polymer/clay nanocomposites, especially those with processing temperatures well above 200xc2x0 C., is neither contemplated nor disclosed.
Therefore, a need still exists for a colorant composition, a polymer-clay nanocomposite comprising the colorant composition and articles produced from the polymer-clay nanocomposite that have improved color and/or appearance.
In accordance with the purpose(s) of this invention, as embodied and broadly described herein, this invention, in one embodiment, relates to a polymer-clay nanocomposite comprising (i) a melt-processible matrix polymer, and incorporated therein (ii) a colorant composition comprising a clay material intercalated with at least one cationic colorant having a cation group and a chromophore group.
In another embodiment, this invention relates to a polymer-clay nanocomposite comprising (i) a melt-processible matrix polymer, and incorporated therein (ii) an optical brightener composition comprising a clay material intercalated with at least one optical brightener having a cation group and a chromophore group.
In another embodiment, this invention relates to a colorant composition comprising (i) at least one cationic colorant having a cation group and a chromophore group, wherein the cation group is separated from the chromophore group by at least two carbons, and (ii) a clay material intercalated with the cationic colorant.
In yet another embodiment, this invention relates to a composition comprising (i) at least one optical brightener having a cation group and a chromophore group, wherein the cation group is separated from the chromophore group by at least two carbons, and (ii) a clay material intercalated with the optical brightener.
In yet another embodiment, the present invention relates to a process for preparing a polymer-clay nanocomposite comprising (i) preparing an intercalated layered clay material by reacting a swellable layered clay material with a cationic colorant, optical brightener, or a mixture thereof, and (ii) incorporating the intercalated clay material in a matrix polymer by melt processing the matrix polymer with the intercalated clay.
Additional advantages of the invention will be set forth in part in the detailed description, which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory of preferred embodiments of the invention, and are not restrictive of the invention, as claimed.
The present invention may be understood more readily by reference to the following detailed description of the invention and the examples provided therein. It is to be understood that this invention is not limited to the specific processes and conditions described, as specific processes and/or process conditions for processing polymers as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
It must also be noted that, as used in the specification and the appended claims, the singular forms xe2x80x9ca,xe2x80x9d xe2x80x9canxe2x80x9d and xe2x80x9cthexe2x80x9d included plural references unless the context clearly dictates otherwise.
Ranges may be expressed herein as from xe2x80x9caboutxe2x80x9d or xe2x80x9capproximatelyxe2x80x9d one particular value and/or to xe2x80x9caboutxe2x80x9d or xe2x80x9capproximatelyxe2x80x9d another particular value. When such a range is expressed, another embodiment includes from the one particular and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent xe2x80x9cabout,xe2x80x9d it will be understood that the particular value forms another embodiment.
Whenever used in this specification or the claims, the terms set forth shall have the following meanings:
xe2x80x9cColorant(s)xe2x80x9d or xe2x80x9ccolorant composition(s)xe2x80x9d shall mean any substance that imparts color to another material or mixture. Colorants are either dyes or pigments and may be naturally present in a material, admixed with a material or applied to it in solution. xe2x80x9cOptical brightener(s)xe2x80x9d or xe2x80x9cfluorescent brightener(s)xe2x80x9d shall mean any fluorescent organic compound that absorbs mainly UV light and emits it as visible light.
xe2x80x9cPigment(s)xe2x80x9d shall mean any substance that imparts color to another material or mixture and is sometimes used synonymously with xe2x80x9ccolorantxe2x80x9d or xe2x80x9cdye.xe2x80x9d Pigments are usually dry powders and may be organic or inorganic.
xe2x80x9cDye(s)xe2x80x9d shall mean any natural or synthetic organic colorant, which may be either acidic or basic. The distinction between natural dyes and pigments is often arbitrary.
xe2x80x9cChromophore(s)xe2x80x9d shall mean a chemical grouping that when present in an aromatic compound (the chromogen), gives color to the compound by causing a displacement of, or appearance of, absorbent bands in the visible spectrum.
xe2x80x9cClay(s),xe2x80x9d xe2x80x9cclay material(s),xe2x80x9d xe2x80x9cLayered clay(s)xe2x80x9d or xe2x80x9clayered clay material(s)xe2x80x9d shall mean any organic or inorganic material or mixtures thereof, such as a smectite clay mineral, which is in the form of a plurality of adjacent, bound layers. The layered clay comprises platelet particles and is typically swellable.
xe2x80x9cPlatelet particles,xe2x80x9d xe2x80x9cplateletsxe2x80x9d or xe2x80x9cparticlesxe2x80x9d shall mean individual or aggregate unbound layers of the layered clay material. These layers may be in the form of individual platelet particles, ordered or disordered small aggregates of platelet particles (tactoids), and small aggregates of tactoids.
xe2x80x9cDispersionxe2x80x9d or xe2x80x9cdispersedxe2x80x9d is a general term that refers to a variety of levels or degrees of separation of the platelet particles. The higher levels of dispersion include, but are not limited to, xe2x80x9cintercalatedxe2x80x9d and xe2x80x9cexfoliated.xe2x80x9d
xe2x80x9cIntercalatedxe2x80x9d or xe2x80x9cintercalate(s)xe2x80x9d shall mean a layered clay material that includes an intercalant, e.g. cationic colorant, disposed between adjacent platelet particles or tactoids of the layered material.
xe2x80x9cExfoliatexe2x80x9d or xe2x80x9cexfoliatedxe2x80x9d shall mean platelets dispersed predominantly in an individual state throughout a carrier material, such as a matrix polymer. Typically, xe2x80x9cexfoliatedxe2x80x9d is used to denote the highest degree of separation of platelet particles.
xe2x80x9cExfoliationxe2x80x9d shall mean a process for forming an exfoliate from an intercalated or otherwise less dispersed state of separation.
xe2x80x9cNanocomposite(s)xe2x80x9d or xe2x80x9cnanocomposite composition(s)xe2x80x9d shall mean a polymer or copolymer having dispersed therein a plurality of individual platelets obtained from an exfoliated, layered and intercalated clay material.
xe2x80x9cMatrix polymerxe2x80x9d shall mean a thermoplastic or melt-processible polymer in which the clay intercalate is dispersed to form a nanocomposite. In this invention, however, the platelet particles are predominantly exfoliated in the polymer to form a nanocomposite.
The present invention relates generally to a colorant or optical brightener composition comprising a layered clay material that is intercalated with at least one cationic colorant, optical brightener and/or a mixture thereof. This invention also relates generally to a polymer nanocomposite comprising a melt-processible matrix polymer and the composition, and to molded articles, film or fiber produced from the polymer nanocomposite.
One embodiment of this invention relates to colorant compositions comprising a clay material that is intercalated with one or more cationic dyes and/or optical brighteners having a cation group and a chromophore group, wherein the cation group is separated from the chromophore group by at least two carbon atoms. These colorant compositions have exceptional thermal stability and are, therefore, more useful for incorporation into thermoplastic polymers by a wider variety of methods, e.g., the compositions could withstand polymerization conditions. Other structures may also have sufficient thermal stability under processing, e.g., compounding conditions.
In another embodiment, this invention relates to a polymer nanocomposite, preferably a polyester nanocomposite. The desired colorant composition and any additional clay material desired are added to monomers or oligomers, and polymerization processes known in the art prepare the polymer nanocomposite. In yet another embodiment of this invention, the desired colorant compositions and any additional clay material desired are melt-compounded with a melt-processable matrix polymer to form the nanocomposite of this invention.
Many of the suitable clay materials, especially the natural clays, are colored. In an embodiment of this invention, the clay material is intercalated with a sufficient amount of the appropriate one or more cationic dyes to cover the color of the clay in the nanocomposite to produce a colorless or slightly colored nanocomposite. In another embodiment of this invention, the clay material is intercalated with sufficient amount of the appropriate one or more cationic dyes required to impart a desired color to the nanocomposite. In yet another embodiment of this invention, one or more pigments are used in combination to attain the nanocomposite with the desired color. In still another embodiment of this invention, one or more pigments are used in combination with a dye-free clay, which is typically intercalated or treated, to achieve the desired color and nanocomposite properties.
Frequently, achieving the desired appearance requires the use of more than one dye or the combination of dyes and an optical brightener. The dyes and optical brighteners may be co-intercalated into the same clay, optionally with other intercalants, or may be used individually to intercalate clays, optionally with other intercalants, and then combined into the composite, optionally with additional dye-free clay which is typically modified, in the appropriate amounts to achieve the desired appearance. Thus, the range of color and amount of color may vary substantially depending on many factors including choice and concentration of cationic colorants and/or optical brighteners, choice and concentration of clays, choice and concentration of dye-free clay, and choice and concentration of other additives.
The colorant compositions or pigments of this invention may be prepared by intercalating a cationic colorant and/or an optical brightener into the gallery of the layered clay material. Many processes to intercalate materials, especially organic cation salts, into clays are known, and may be used in the process of this invention. Illustrative of these processes is the modification of a layered clay with one or more cationic colorants by the process of dispersing a layered clay into hot water, most preferably from 50 to 80xc2x0 C., adding the desired cationic colorant salts separately or adding a mixture of the cationic colorant salts (neat or dissolved in water or alcohol) with agitation, then blending for a period of time sufficient for the organic cations to exchange most of the metal cations present in the galleries between the layers of the clay material. Then, the pigment is isolated by methods known in the art including, but not limited to, filtration, centrifugation, spray drying, and their combinations.
It is desirable to use a sufficient amount of the organic cation colorant salts to permit exchange of the metal cations in the galleries of the layered particle for organic cations; therefore, at least about 0.5 equivalent of total organic cation salts is used and up to about 3 equivalents of organic cation salts can be used. It is preferred that about 0.5 to 2 equivalents of organic cation colorant salts be used, more preferable about 1.0 to 1.5 equivalents. It is desirable, but not required, to remove most of the metal cation salts and most of the excess organic cation colorant salts by washing and other techniques known in the art.
The particle size of the resulting colorant or pigment is reduced in size by methods known in the art, including, but not limited to, grinding, pulverizing, hammer milling, jet milling, and their combinations. It is preferred that the average particle size be reduced to less than 100 micron in diameter, more preferably less than 50 micron in diameter, and most preferably less than 20 micron in diameter. The process to prepare the colorant composition or pigment may be conducted in a batch, semi-batch, or continuous manner.
Any cationic (basic) colorant may be used in the polymer nanocomposite or in the practice of this invention, and many cationic colorants are known (see for example Colour Index, 3rd Ed., Vol. 1, pp. 1611-1688, The Soc. of Dyers and Colourists, 1997). It has been unexpectedly found that some colorants or pigments have excellent thermal stability and are therefore more generally useful and more generally preferred for the formation of polymer nanocomposites.
More particularly, it has been discovered that colorant or pigment compositions comprising a clay material that is intercalated with a cation (basic) dye in which the cation group or groups are separated from the chromophore group by at least two carbon atoms have unexpectedly good thermal stability and are sufficiently thermally stable to permit the preparation of polymer nanocomposites by in-situ polymerization processes, for example, which typically require prolonged heating at temperature above the melting point of the polymer.
The preferred colorants useful in the practice of this invention correspond to the general formula (I):
[A]xe2x80x94(Xxe2x80x94Rxe2x80x94Y)nxe2x80x83xe2x80x83(I)
wherein
A is a mono-, di-, tri-, or tetra-valent colorant moiety comprising the chromophoric classes of anthraquinones, methines, anthrapyridones, triphenodioxazines, fluorindines, phthaloylpyrrocolines, coumarins, phthaloylacridones, 4-amino-1,8-naphthalimidies, thioxanthrones, 2,5-arylaminoterephthalic acids or esters, benzanthrones, 3,6-diaminopyromellitic acid diimides, quinophthalones, naphthalene 1:4:5:8-tetra carboxylic bis-imides; isothiazoloanthrones, anthrapyrimidines, anthrapyrimidones, indanthrones, phthalocyanines, naphthalocyanines, perinones, 3-aryl-2,5-dioxypyrrolines, 3,4,9,10-perylenetetracarboxylic acid diimides, or 5-arylidene-2-(5H)furanones;
X is a linking group comprising xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x80x94CO2xe2x80x94, xe2x80x94CON(R1)xe2x80x94, xe2x80x94SO2N(R1)xe2x80x94, or a covalent bond, wherein R1 is hydrogen, C1-C8 alkyl, aryl, or C5-C7 cycloalkyl;
R is C2-C8 alkylene or xe2x80x94(C2-C8 alkylene)-[(X-(C2-C8 alkylene)]1-3xe2x80x94;
Y is a moiety having the general formula (II):
xe2x80x83wherein Zxe2x88x92 is a halogen ion; R2 is C1-C8 alkyl or C2-C8 alkenyl; R3 and R4 are independently C1-C8 alkyl, C3-C8 alkenyl, C5-C7 cycloalkyl, or may be combined to produce a moiety having the general formula (III):
xe2x80x83wherein
X1 is a covalent bond, xe2x80x94CH2xe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SO2xe2x80x94, or xe2x80x94N(R5)xe2x80x94, wherein R5 is an acyl radical; and n is 1-4.
In the above definitions, the term C1-C8 alkyl is used to denote a straight or branched chain saturated hydrocarbon radical containing one to eight carbon and this radical substituted with C1-C8 alkoxy, aryl or C3-C7 cycloalkyl. The term C3-C8 alkenyl is used to describe a straight or branched chain monovalent hydrocarbon radical having three to eight carbons and containing at least one carbon to carbon double bond. The term C5-C7 cycloalkyl is used to describe a saturated cyclic hydrocarbon monovalent radical containing five to seven carbons and which may be substituted with at least one C1-C8 alkyl group. The term aryl is used to describe a phenyl radical and phenyl substituted with one or more groups selected from C1-C8 alkyl, C1-C8 alkoxy, or halogen. The term C2-C8 alkylene is used to describe a straight or branched chain divalent hydrocarbon radical containing two to eight carbon atoms. The term acyl is used to describe the following structures: xe2x80x94COxe2x80x94(C1-C8 alkyl), xe2x80x94CO-(aryl), xe2x80x94CO2xe2x80x94(C1-C8 alkyl), xe2x80x94SO2xe2x80x94(C1-C8 alkyl), xe2x80x94SO2-aryl, and xe2x80x94SO2xe2x80x94(C5-C7 cycloalkyl). The term halogen is used to denote fluorine, chlorine, bromine, and iodine.
Suitable optical brighteners are selected from the classes of stilbenes, styrylbenoxazoles, coumarins, benzocoumarins, 1,4-bis(benzoxazolyl-2xe2x80x2-yl)-naphthalones, naphthalimides, thiophene oxazoics, pyrazolines, xanthenes, and the like, and have cationic (basic) sites rendering them suitable for dyeing acrylic fibers, for example (see Colour Index, 3rd Ed., Vol. 2, pp. 2745-2771, The Soc. of Dyers and Colourists, 1971).
The colorant composition and polymer-clay nanocomposite of the present invention comprise less than about 25 weight percent, preferably from about 0.5 to about 20 weight percent, more preferably from about 0.5 to about 15 weight percent, and most preferably from about 0.5 to about 10 weight percent of a swellable layered clay material that is intercalated with a cationic colorant.
The intercalated clay material of the colorant composition has platelet particles, which are dispersed in the polymer to form the polymer-clay nanocomposite. The polymer nanocomposite is preferably a polyester polymer or copolymer nanocomposite having an I.V. of at least 0.7 dL/g as measured in phenol/tetrachloroethane (60 wt. %/40 wt. %) at 25xc2x0 C. The amount of platelet particles is determined by measuring the amount of silicate residue in the ash of the polymer/platelet composition when treated in accordance with ASTM D5630-94.
Useful clay materials include natural, synthetic, and modified phyllosilicates. Illustrative of such natural clays is smectite clays, such as montmorillonite, saponite, hectorite, mica, vermiculite, bentonite, nontronite, beidellite, volkonskoite, saponite, magadite, kenyaite, and the like. Illustrative of such synthetic clays is synthetic mica, synthetic saponite, synthetic hectorite, and the like. Illustrative of such modified clays are fluoronated montmorillonite, fluoronated mica, and the like. Suitable clays are available from various companies including Nanocor, Inc., Southern Clay Products, Kunimine Industries, Ltd., and Rheox.
Preferred clay materials are phyllosilicates of the 2:1 type having a cation exchange capacity of 0.3 to 2.0 milliequivalents per gram of mineral (meq/g). The most preferred clay materials are smectite clay minerals, particularly bentonite or montmorillonite, more particularly Wyoming-type sodium montmorillonite or Wyoming-type sodium bentonite.
Generally, the layered clay materials useful in this invention are an agglomeration of individual platelet particles that are closely stacked together like cards, in domains called tactoids. The individual platelet particles of the clays preferably have thickness of less than about 2 nm and diameter in the range of about 10 to about 3000 nm. Preferably, the clays are dispersed in the polymer so that most of the clay material exists as individual platelet particles, small tactoids, and small aggregates of tactoids. Preferably, a majority of the tactoids and aggregates in the polymer/clay nanocomposites of the present invention will have thickness in its smallest dimension of less than about 20 nm. Polymer/clay nanocomposite compositions with the higher concentration of individual platelet particles and fewer tactoids or aggregates are preferred.
Moreover, the layered clay materials are typically swellable free flowing powders having a cation exchange capacity from about 0.3 to about 3.0 meg/q, more preferably from 0.9 to about 1.5 meq/g and most preferably from 0.95 to about 1.25 meq/g. The clay may have a wide variety of exchangeable cations present in the galleries between the layers of the clay, including, but not limited to, cations comprising the alkaline metals (group IA), the alkaline earth metals (group IIA), and their mixtures. The most preferred cation is sodium; however, any cation or combination of cations may be used provided that most of the cations are exchanged for organic colorant cations during the process of this invention.
Other non-clay materials having the above-described ion-exchange capacity and size, such as chalcogens, may also be used as the source of platelet particles under the present invention. Chalcogens are salts of a heavy metal and group VIA (O, S, Se, and Te). These materials are known in the art and do not need to be described in detail here.
If desired, the clay material may be treated for the purposes of aiding dispersion or exfoliation in a polymer and/or improving the strength of the polymer/clay interface, and any treatment that achieves the above goals may be used before, during, or after intercalation of the clay with one or more colorants, optical brighteners, and/or their mixtures.
Examples of useful treatments include intercalation of the clay with water soluble or water insoluble polymers, oligomers, monomers, or organic compounds, silane compounds, metals, organometallics, other organic cations, and/or their combinations, dispersion of the clay into a solvent or dispersing aid, compounding into oligomeric materials, adding or mixing dispersing aids, and the like.
Treatment of the clay can be accomplished prior to the addition of a water-dispersible polymer to the clay material, during the dispersion of the clay with a water-soluble polymer or during a subsequent melt blending or melt fabrication step.
Examples of useful pretreatment with polymers and oligomers include those disclosed in U.S. Pat. Nos. 5,552,469 and 5,578,672, incorporated herein by reference. Examples of useful polymers for treating the intercalated clays include polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, polytetrahydrofuran, polystyrene, polycaprolactone, certain water-dispersible polyesters, Nylon-6, poly(m-xylylene adipamide) and the like.
Examples of useful pretreatment with organic reagents and monomers include those disclosed in EP 780,340 A1, incorporated herein by reference. Examples of useful organic reagents and monomers for intercalating the swellable layered clay include dodecylpyrrolidone, caprolactone, caprolactam, ethylene carbonate, ethylene glycol, bishydroxyethyl terephthalate, dimethyl terephthalate, adipic acid, m-xylylenediamine and the like or mixtures thereof.
Examples of useful pretreatment with silane compounds include those treatments disclosed in WO 93/11190, incorporated herein by reference. Examples of useful silane compounds includes (3-glycidoxypropyl)trimethoxysilane, 2-methoxy(polyethyleneoxy)propyl heptamethyl trisiloxane, octadecyl dimethyl (3-trimethoxysilylpropyl) ammonium chloride and the like.
Organic cations that can be used to intercalate the clay material of the colorant composition and/or nanocomposite of this invention are derived from organic cation salts, preferably onium salt compounds. Organic cation salts useful for the colorant composition and nanocomposite of this invention may generally be represented as follows:
wherein
M is either nitrogen or phosphorous; Xxe2x88x92 is a halide, hydroxide, or acetate anion, preferably chloride and bromide; and R1, R2, R3, and R4 are independently organic and oligomeric ligands or may be hydrogen.
Examples of useful organic ligands include, but are not limited to, linear or branched alkyl groups having 1 to 22 carbon atoms, more preferably 1 to 12 carbon atoms, aralkyl groups which are benzyl and substituted benzyl moieties including fused-ring moieties having linear chains or branches of 1 to 100 carbon atoms, more preferably 1 to 12 carbon atoms, in the alkyl portion of the structure, aryl groups such as phenyl and substituted phenyl including fused-ring aromatic substituents, beta, gamma unsaturated groups having six or less carbon atoms, and alkyleneoxide groups having 2 to 6 carbon atoms, more preferably 3 to 5 carbon atoms. Examples of useful oligomeric ligands include, but are not limited to, poly(alkylene oxide), polystyrene, polyacrylate, polycaprolactone, and the like.
Useful organic cations for this invention also include, but are not limited to, alkyl ammonium ions, such as dodecyl ammonium, octadecyl ammonium, bis(2-hydroxyethyl)octadecyl methyl ammonium, octadecyl benzyl dimethyl ammonium, tetramethyl ammonium, and the like, and alkyl phosphonium ions such as tetrabutyl phosphonium, trioctyl octadecyl phosphonium, tetraoctyl phosphonium, octadecyl triphenyl phosphonium, and the like.
Illustrative examples of suitable polyalkoxylated ammonium compounds include the hydrochloride salts of polyalkoxylated amines such as JEFFAMINE (of Huntsman Chemical), namely, JEFFAMINE-506, which was analyzed to be an oligooxyethlene amine with number average molecular weight of about 1100 g/mol, and JEFFAMINE 505 which was analyzed to be an oligooxypropylene amine with number average molecular weight of about 640 g/mol. Other hydrochloride salts of polyalkoxylated amines include the hydrochloride salt of ETHOMEEN 18/25 (of Akzo Chemie America), which is octadecyl bis(polyoxyethylene[15])amine, wherein the numbers in brackets refer to the total number of ethylene oxide units. ETHOQUAD (of Akzo Chemie America), or, namely, ETHOQUAD 18/25, which is octadecyl methyl bis(polyoxyethylene[15]) ammonium chloride is an example of a salt of a polyalkoxylated amine. Preferred polyalkoxylated organic cations for use in polyesters, such as poly(ethylene terephthalate), are polyalkoxylated ammonium compounds.
Numerous methods to modify layered clays with organic cations are known, and any of these may be used in the process of this invention.
If desired, a dispersing aid may be present during or prior to the formation of the composite by melt mixing for the purposes of aiding exfoliation of the treated or untreated swellable layered particles into the polymer. Many such dispersing aids are known, covering a wide range of materials including water, alcohols, ketones, aldehydes, chlorinated solvents, hydrocarbon solvents, aromatic solvents, and the like or combinations thereof.
It should be appreciated that on a total composition basis, dispersing aids and/or pretreatment compounds may account for significant amount of the total composition, in some cases up to about 30 weight percent. While it is preferred to use as little dispersing aid/pretreatment compounds as possible, the amounts of dispersing aids and/or pretreatment compounds may be as much as about 8 times the amount of the platelet particles.
This invention also relates to polymer nanocomposites comprising the colorant compositions of this invention. The polymer nanocomposite compositions of this invention may comprise a wide range of materials depending on the pigment and polymer selected. Any melt processible polymer may be used in this invention. Illustrative of melt-processible polymers are polyesters, polyetheresters, polyamides, polyesteramides, polyurethanes, polyimides, polyetherimides, polyureas, polyamideimides, polyphenyleneoxides, phenoxy resins, epoxy resins, polyolefins, polyacrylates, polystyrenes, polyethylene-co-vinyl alcohols (EVOH), and the like or their combinations and blends. Although the preferred polymers are linear or nearly linear, polymers with other architectures, including branched, star, cross-linked and dendritic structures may be used, if desired.
The preferred polymers include those materials that are suitable for use in the formation of multilayer structures with polyesters, and include polyesters, polyamides, polyethylene-co-vinyl alcohols (such as EVOH) and similar or related polymers and/or copolymers. The preferred polyester is poly(ethylene terephthalate) (PET) or a copolymer thereof. The preferred polyamide is poly(m-xylylene adipamide or a copolymer thereof.
Suitable polyesters include at least one dibasic acid and at least one glycol. The primary dibasic acids are terephthalic, isophthalic, naphthalenedicarboxylic, 1,4-cyclohexanedicarboxylic acid and the like. The various isomers of naphthalenedicarboxylic acid or mixtures of isomers may be used, but the 1,4-, 1,5, 2,6-, and 2,7-isomers are preferred. The 1,4-cyclohexanedicarboxylic acid may be in the form of cis, trans, or cis/trans mixtures. In addition to the acid forms, the lower alkyl esters or acid chlorides may be also be used.
The polyester may be prepared from one or more of the following dicarboxylic acids or glycols.
The dicarboxylic acid component of the polyester may optionally be modified with up to about 50 mole percent of one or more different dicarboxylic acids. Such additional dicarboxylic acids include dicarboxylic acids having from 6 to about 40 carbon atoms, and more preferably dicarboxylic acids selected from aromatic dicarboxylic acids preferably having 8 to 14 carbon atoms, aliphatic dicarboxylic acids preferably having 4 to 12 carbon atoms, or cycloaliphatic dicarboxylic acids preferably having 8 to 12 carbon atoms. Examples of suitable dicarboxylic acids include phthalic acid, terephthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, cyclohexanedicarboxylic acid, cyclohexanediacetic acid, diphenyl-4,4xe2x80x2-dicarboxylic acid, phenylene (oxyacetic acid) succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and the like. Polyesters may also be prepared from two or more of the above dicarboxylic acids.
Typical glycols used in the polyester include those containing from two to about ten carbon atoms. Preferred glycols include ethylene glycol, propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, diethylene glycol, neopentyl glycol, and the like. The glycol component may optionally be modified with up to about 50 mole percent, preferably up to about 25 mole percent, and more preferably up to about 15 mole percent of one or more different diols. Such additional diols include cycloaliphatic diols preferably having 6 to 20 carbon atoms or aliphatic diols preferably having 3 to 20 carbon atoms. Examples of such diols include: diethylene glycol, neopentyl glycol, triethylene glycol, 1,4-cyclohexanedimethanol, propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, 3-methylpentanediol-(2,4), 2-methylpentanediol-(1,4), 2,2,4-trimethylpentane-diol-(1,3), 2-ethylhexanediol-(1,3), 2,2-diethylpropane-diol-(1,3), hexanediol-(1,3), 1,4-di-(2-hydroxyethoxy)-benzene, 2,2b-is-(4-hydroxycyclohexyl)-propane, 2,4-dihydroxy-1,1,3,3-tetramethyl-cyclobutane, 2,2-bis-(3-hydroxyethoxyphenyl)-propane, 2,2-bis-(4-hydroxypropoxyphenyl)-propane and the like. Polyesters may also be prepared from two or more of the above diols.
Small amounts of multifunctional polyols such as trimethylolpropane, pentaerythritol, glycerol and the like may be used, if desired. When using 1,4-cyclohexanedimethanol, it may be the cis, trans or cis/trans mixtures. When using phenylenedi(oxyacetic acid), it may be used as 1,2; 1,3; 1,4 isomers, or mixtures thereof.
The polymer may also contain small amounts of trifunctional or tetrafunctional comonomers to provide controlled branching in the polymers. Such comonomers include trimellitic anhydride, trimethylolpropane, pyromellitic dianhydride, pentaerythritol, trimellitic acid, trimellitic acid, pyromellitic acid and other polyester forming polyacids or polyols generally known in the art.
Suitable polyamides include partially aromatic polyamides, aliphatic polyamides, wholly aromatic polyamides and/or mixtures thereof. By xe2x80x9cpartially aromatic polyamide,xe2x80x9d it is meant that the amide linkage of the partially aromatic polyamide contains at least one aromatic ring and a nonaromatic species. Suitable polyamides have an article forming molecular weight and preferably an I.V. of greater than 0.4.
Preferred wholly aromatic polyamides comprise in the molecule chain at least 70 mole % of structural units derived from m-xylylene diamine or a xylylene diamine mixture comprising m-xylylene diamine and up to 30% of p-xylylene diamine and an aliphatic dicarboxylic acid having 6 to 10 carbon atoms, which are further described in Japanese Patent Publications No. 1156/75, No. 5751/75, No. 5735/75 and No. 10196/75 and Japanese Patent Application Laid-Open Specification No. 29697/75.
Polyamides formed from isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, meta- or para-xylylene diamine, 1,3- or 1,4-cyclohexane(bis)methylamine, aliphatic diacids with 6 to 12 carbon atoms, aliphatic amino acids or lactams with 6 to 12 carbon atoms, aliphatic diamines with 4 to 12 carbon atoms, and other generally known polyamide forming diacids and diamines can be used. The low molecular weight polyamides may also contain small amounts of trifunctional or tetrafunctional comonomers such as trimellitic anhydride, pyromellitic dianhydride, or other polyamide forming polyacids and polyamines known in the art.
Preferred partially aromatic polyamides include, but are not limited to poly(m-xylylene adipamide), poly(m-xylylene adipamide-co-isophthalamide), poly(hexamethylene isophthalamide), poly(hexamethylene isophthalamide-co-terephthalamide), poly(hexamethylene adipamide-co-isophthalamide), poly(hexamethylene adipamide-co-terephthalamide), poly(hexamethylene isophthalamide-co-terephthalamide) and the like or mixtures thereof. More preferred partially aromatic polyamides include, but are not limited to poly(m-xylylene adipamide), poly(hexamethylene isophthalamide-co-terephthalamide), poly(m-xylylene adipamide-co-isophthalamide), and/or mixtures thereof. The most preferred partially aromatic polyamide is poly(m-xylylene adipamide).
Preferred aliphatic polyamides include, but are not limited to poly(hexamethylene adipamide) and poly(caprolactam). The most preferred aliphatic polyamide is poly(hexamethylene adipamide). Partially aromatic polyamides are preferred over the aliphatic polyamides where good thermal properties are crucial.
Preferred aliphatic polyamides include, but are not limited to polycapramide (nylon 6), poly-aminoheptanoic acid (nylon 7), poly-aminonanoic acid (nylon 9), polyundecane-amide (nylon 11), polyaurylactam (nylon 12), poly(ethylene-adipamide) (nylon 2,6), poly(tetramethylene-adipamide) (nylon 4,6), poly(hexamethylene-adipamide) (nylon 6,6), poly(hexamethylene-sebacamide) (nylon 6,10), poly(hexamethylene-dodecamide) (nylon 6,12), poly(octamethylene-adipamide) (nylon 8,6), poly(decamethylene-adipamide) (nylon 10,6), poly(dodecamethylene-adipamide) (nylon 12,6) and poly(dodecamethylene-sebacamide) (nylon 12,8).
The most preferred polyamides include poly(m-xylylene adipamide), polycapramide (nylon 6) and poly(hexamethylene-adipamide) (nylon 6,6). Poly(m-xylylene adipamide) is a preferred polyamide due to its availability, high barrier, and processability.
The polyamides are generally prepared by processes which are well known in the art.
Although not necessarily preferred, the polymers of the present invention may also include additives normally used in polymers. Illustrative of such additives known in the art are carbon black, glass fibers, fillers, impact modifiers, antioxidants, stabilizers, flame retardants, reheat aids, crystallization aids, acetaldehyde reducing compounds, recycling release aids, oxygen scavengers, plasticizers, nucleators, mold release agents, compatibilizers, and the like, or their combinations.
All of these additives and many others and their use are known in the art and do not require extensive discussion. Therefore, only a limited number will be referred to, it being understood that any of these compounds can be used in any combination so long as they do not hinder the present invention from accomplishing its objects.
This invention also relates to articles prepared from the nanocomposite material of this invention, including, but not limited to film, fibers, sheet, pipes, tubes, profiles, molded articles, preforms, stretch blow molded films and containers, injection blow molded containers, extrusion blow molded films and containers, thermoformed articles and the like. The containers are preferably bottles. The utility of nanocomposites has been established. The advantages of the nanocomposites of this invention include the preparation of molded articles, films, and fibers with improved appearance. In addition, the colored molded articles, films, and fibers of this invention have excellent light fastness and color stability.
The bottles and containers of this invention may also provide increased shelf storage life for contents, including beverages and food that are sensitive to the permeation of gases. Articles, more preferably containers, of the present invention may display a gas transmission or permeability rate (oxygen, carbon dioxide, water vapor) at least 10% lower (depending on clay concentration) than that of similar containers made from clay-free polymer, resulting in correspondingly longer product shelf life provided by the container. Desirable values for the sidewall modulus and tensile strength may also be maintained.
The articles may also be multilayered. Preferably, the multilayered articles have a nanocomposite material disposed intermediate to other layers, although the nanocomposite may also be one layer of a two-layered article. In embodiments where the nanocomposite and its components are approved for food contact, the nanocomposite may form the food contact layer of the desired articles. In other embodiments it is preferred that the nanocomposite be in a layer other than the food contact layer.
The multilayer articles may also contain one or more layers of the nanocomposite composition of this invention and one or more layers of a structural polymer. A wide variety of structural polymers may be used. Illustrative of structural polymers are polyesters, polyetheresters, polyamides, polyesteramides, polyurethanes, polyimides, polyetherimides, polyureas, polyamideimides, polyphenyleneoxides, phenoxy resins, epoxy resins, polyolefins, polyacrylates, polystyrene, polyethylene-co-vinyl alcohols (EVOH), and the like or their combinations and blends. The preferred structural polymers are polyesters, such as poly(ethylene terephthalate) and its copolymers.
In another embodiment of this invention, the polymer-clay nanocomposite and the molded article or extruded sheet may be formed at the same time by co-injection molding or co-extruding.
Another embodiment of this invention is the combined use of silicate layers uniformly dispersed in the matrix of a high barrier thermoplastic together with the multilayer approach to packaging materials. By using a layered clay, the amount of material that is needed to generate a specific barrier level in the end application is greatly reduced.
Since the high barrier material is often the most expensive component in multilayer packaging, a reduction in the amount of this material used can be quite beneficial. With the nanocomposite layer being sandwiched between two outer polymer layers, the surface roughness is often considerably less than for a monolayer nanocomposite material. Thus, with a multilayer approach, the level of haze is reduced.

Colorant composition, a polymer nanocomposite comprising the colorant composition and articles produced therefrom

University of South Carolina Research Foundation


A testing system and method for performing integrity testing in a gas piping system include using a motorized pump to pressurize the piping system. A pressure sensor is used for measuring the pressure in the piping system, and an input device receives inputs from an operator related to a test to be performed. An output device is provided for communicating information to the operator. A control system includes at least one controller and is configured to: control the pump to pressurize the piping system to a predetermined pressure, receive inputs from the pressure sensor, and output data related to the pressure of the piping system.

Often, during the course of routine maintenance, gas meter exchanges—both standard and automated meter reading (AMR) meters—gas conversions, system upgrades, installation and testing of service pipes, and during emergencies, natural gas supplied to a commercial building or residence must be shut off. Once the work is performed, gas may be restored to the premises, or at a minimum, gas is restored between the service and the gas main. Prior to introducing gas to the end use equipment and/or in-house or service piping, an integrity test of the piping may be required.
Integrity tests help provide a level of confidence that the piping, fittings and couplings in the system are capable of maintaining the pressure that will be generated and sustained during normal gas usage, prior to re-energizing the pipe with gas. A large number of integrity tests are performed by utility companies and their contractors each day and are integral in ensuring that the safety of residences, businesses and technicians is maintained.
An integrity test helps to detect leaks and breaches in pipe, fittings, and connections to end use equipment, and helps to provide a level of confidence that the work performed on the piping was completed satisfactorily as to not allow a gas leak once reinstated. After updating, upgrading or repairing the gas piping, gas meter or end use equipment in a building, the following general procedure may be used to perform an integrity test.
A combination of devices and tubes, commonly known as a "Christmas Tree", consisting of an aspirator ball on a valve, a tee, a manifold and a manometer, is connected to the service pipe before the meter set and air is pumped by hand into the piping to generate pressure of six to eight inches of water column inside the piping. Depending on the size of the building and the size of the piping, the time required to pump the service piping up to the required pressure by hand can be 30 minutes or more. The mechanic performing the integrity test watches the manometer for a predetermined time period. If the pressure remains constant throughout the test, the integrity of the piping and connections is confirmed. The mechanic fills out a report by hand that establishes pertinent information relative to the test that was performed (time, date, location, mechanic name, test results, etc.).
Because this process is performed by many different mechanics, it is difficult, if not impossible, to obtain consistent results or to ensure that the proper procedure is followed each time. Additionally, errors made during the report generation stage, due to illegible hand writing, misspellings, accidental typographical errors, etc., can cause the results provided to the gas distribution company to be flawed.
Therefore, a system and method for automating the integrity test process that can reduce the potential for human error would be beneficial because it would reduce risk, minimize the time required to perform testing, generate an accurate reporting trail and provide technicians a tool to use in their daily work.

System and method for automated integrity testing


A method is provided for preparing oxazole intermediates of the structure ##STR1## (wherein R is alkyl) wherein an oxazoline of the structure ##STR2## is oxidized employing an oxidizing agent such as cupric bromide, a base such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and a non-hydride donor amine base such as hexamethylenetetraamine (HMTA). The resulting oxazole may be hydrolyzed to the final anti-thrombotic - anti-vasospastic compounds.

U.S. Pat. No. 5,100,889 to Misra et al discloses 7-oxabicycloheptyl substituted heterocyclic amide prostaglandin analogs which are thromboxane A.sub.2 (TXA.sub.2) receptor antagonists or combined thromboxane A.sub.2 receptor antagonist/thromboxane synthetase inhibitors useful, for example, in the treatment of thrombotic and/or vasospastic diseases, and have good duration of action. Examples of compounds disclosed in Misra et al have the structural formula I ##STR3## and including all stereoisomers thereof, wherein m is 1, 2 or 3; n is 0, 1, 2, 3 or 4;
R.sup.1 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl, cycloalkyl, cycloalkylalkyl, or amide ##STR4## wherein t is 1 to 12 and R.sub.a is lower alkyl, aryl, cycloalkyl, or cycloalkylalkyl); PA1 R.sup.2 is hydrogen, lower alkyl, aryl, or aralkyl; or R.sup.1 and R.sup.2 together with the nitrogen to which they are linked may form a 5- to 8- membered ring; PA1 R.sup.3 is lower alkyl, aryl or aralkyl; and PA1 R.sup.3a is hydrogen, lower alkyl, aryl or aralkyl.
Misra et al disclose that these compounds may be prepared from the oxazoline XV' ##STR5## which is made to undergo oxidation using manganese dioxide, or nickel peroxide, or preferably cupric bromide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to form the oxazole. ##STR6##
The cupric bromide oxidation is carried out at a temperature of within the range of from about 20.degree. C. to about 70.degree. C., employing a molar ratio of cupric bromide to XV' of within the range of from about 2:1 to about 6:1 and a molar ratio of cupric bromide to DBU of within the range of from about 1:1 to about 1:3 in an inert solvent such as ethyl acetate or preferably ethylacetate/chloroform (1:1, v/v).
The so-formed oxazole may then be hydrolyzed by treatment with an aqueous solution of alkali metal base and then aqueous acid to form the corresponding acid.
In accordance with the present invention, it has now been found that the above oxidation of the oxazoline to the oxazole can be dramatically improved in cost, speed, yield and reproducibility by employing with cupric bromide and DBU, a non-hydride donor amine, preferably hexamethylenetetraamine, in an inert organic solvent such as dichloromethane.

Method for preparing 7-oxabicycloheptyl substituted oxazole amide prostaglandin analog intermediates useful in the preparation of anti-thrombotic and anti-vasospastic compounds


Aspects of the disclosure can provide method for identifying a face where multiple images to be identified are received. Each of the multiple images includes a face image part. Each face image of face images in the multiple images to be identified is extracted. An initial figure identification result of identifying a figure in the each face image is determined by matching a face in the each face image respectively to a face in a target image in an image identification library. The face images are grouped. A target figure identification result for each face image in each group is determined according to the initial figure identification result for the each face image in the each group.

Algorithms for identifying a face have found an increasingly wide range of applications, and have a major value in industrial applications. In a scene of application, there often may be only a single picture or very few pictures in each user category of a database of images for retrieval, leading to low diversity of retrievals from the database of images for retrieval. This can greatly impact accuracy in face identification.

Method and device for identifying face, and computer-readable storage medium

Beijing Xiaomi Pinecone Electronics Co., Ltd.


A method for manufacturing a thin film transistor array panel includes forming a gate line and a gate electrode protruding from the gate line on a substrate; forming a gate insulating layer on the gate line and the gate electrode; depositing sequentially a semiconductor material and a metal material on the gate insulating layer; performing a first etching operation on the semiconductor material and the metal material using a first mask to form a semiconductor layer and a metal layer, the metal layer including a data line, a source electrode, and a drain electrode, in which the drain electrode protrudes from the data line, and the source electrode and the drain electrode having an integral shape; and performing a second etching operation on the metal layer using a second mask to divide the source electrode and the drain electrode.

1. Field
The following description relates to a thin film transistor array panel and a manufacturing method thereof. More particularly, the description relates to a thin film transistor array panel and a manufacturing method for reducing skew formed during an etching process.
2. Discussion of the Background
A thin film transistor is used as a switching element to independently drive each pixel in a flat display device, such as a liquid crystal display or an organic light emitting device. The thin film transistor array panel including a thin film transistor may include a scanning signal line (or a gate line) to transmit a scanning signal to the thin film transistor and a data line that transmits a data signal, as well as a pixel electrode connected to the thin film transistor.
The thin film transistor may include a gate electrode that is connected to the gate line, a source electrode that is connected to the data line, a drain electrode that is connected to the pixel electrode, and a semiconductor layer. The semiconductor layer may be disposed on the gate electrode, which may be disposed between the source electrode and drain electrode. The data signal may be transmitted to the pixel electrode from the data line according to the gate signal from the gate line.
The semiconductor layer of the thin film transistor may be made of, without limitation, amorphous silicon, polysilicon (polycrystalline silicon), and a metal oxide.
Recently, an oxide semiconductor using a metal oxide having a lower cost and higher uniformity compared with polycrystalline silicon, as well as having a higher charge mobility and a higher ON/OFF ratio of a current compared with amorphous silicon has been researched.
If forming the oxide semiconductor of the semiconductor layer, the source electrode and the drain electrode may be formed by using a metal such as titanium (Ti) and copper (Cu).
If etching process is performed on an oxide semiconductor formed of titanium or copper by using a dry etching method, the etching rate may be below a reference threshold, such that a wet etching method may be used. Also, if etching process is performed on other materials other than the above described materials, the dry etching method may not be used in lieu of the wet etching to reduce its cost of operation.
If wet etching method is used in the etching process, isotropic etching may be performed, such that an etchant may penetrate into the metal layer positioned under a photosensitive film or a mask, and thereby a skew and/or an under-cut may be generated on side surfaces of the metal layer. Further, the etching process may not penetrate a semiconductor layer or any other layer disposed below the metal layer, such that boundaries the semiconductor layer protrudes beyond the skewed metal layer. In an example, the boundaries or ends of the semiconductor layer may protrude at least 0.5 um beyond the metal layer boundary. The protruded ends of the semiconductor layer may decrease the size of a design area, which may affect resolution quality of the display.
In a conventional 4-mask process, an etch-back process may be used to form the semiconductor layer, the source electrode, and the drain electrode using one mask. In the etch-back process, the photosensitive film may be etched such that a portion of the photosensitive film may be etched to provide a cavity or a channel portion in the photosensitive film to expose a portion of a layer including the source electrode and the drain electrode. In an example, etch back process may be performed on the photosensitive film with differing heights, such that the lower portion may be etched away to expose a portion of the metal layer while higher portions of the photosensitive film remains.
Accordingly, a boundary of the semiconductor layer and the boundary of the layer including the source electrode and the drain electrode may not correspond to each other. More specifically, edges of the layer including the source electrode and the drain electrode may be skewed, so that the semiconductor layer protrudes beyond the boundary of the layer including the source electrode and the drain electrode. However, the portion where the semiconductor layer that is protruded from the source electrode and the drain electrode may be unnecessary, and may cause a problem that a design margin must be increased.
The above information disclosed in this background section is only for enhancement of understanding of this disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

Thin film transistor display panel and manufacturing method thereof


The present invention relates to a composition comprising nanoparticles stabilized by an at least partially deprotonated biopolymer and a method for the preparation thereof.

Nanotechnology, in particular synthesis and use of nanoparticles, is introduced in many fields and features a plurality of possible applications such as chemical or biological detectors, drug delivery systems, new generation of laser, reinforced materials, thermal barriers and ink jet systems as well as textiles.
Most of the known synthetic methods for the production of silver nanoparticles rely on the use of organic solvents, such as acetone, chloroform, DMSO, etc., and toxic reducing agents, such as hydrazine, DMF, sodium borohydride, etc., in addition to separate stabilizing agents. All previous chemicals are toxic and pose potential environmental and biological risks. Besides this, said substances cause high costs and are therefore not favorable for an industrial application.
Vigneshwaran et al., Carbohydrate research, 2006, 341, 2012-2028, relates to the "green" synthesis of stable silver nanoparticles using soluble starch. It is disclosed that the preparation was carried out in an autoclave at 15 psi at 121° C. for 5 minutes. The nanoparticles obtained this way were found to be stable in aqueous solution over a period of 3 months at room temperature. Soluble starch in terms of this disclosure means linear amylose which was obtained from native starch by separation from the insoluble part (branched amylopectin). The disclosed nanoparticle solutions featured a low concentration of only 50 ppm of silver nanoparticles.
US 2010/0172997 A1 relates to gold, silver and copper nanoparticles stabilized in biocompatible aqueous media. It is disclosed that the nanoparticles can be prepared by photo reduction and thermolysis. Biopolymers such as chitosan, PVA, HPC, PEG, algenic acid etc. were used as stabilizing agents.
US 2007/0269880 A1 relates to a stabilizing solution for submicronic particles. In particular, the synthesis of silver and gold nanoparticles using bitter gourd extract is disclosed. The particles prepared this way feature diameters in a range from 20 to 150 nm. Moreover, a broadening in size distribution of the formed particles was observed.
US 2006/0045916 A1 relates to a method for preparing silver nanoparticles by the reduction of silver ions using phosphine amino acids. The particles are stabilized by a starch previously dissolved in water at a temperature of 100° C.
It is an object of the present invention to provide well stabilized, highly concentrated compositions comprising nanoparticles having a narrow size distribution which can be prepared at low costs under ambient conditions.

Composition comprising nanoparticles and a method for the preparation thereof


A timepiece which simultaneously displays the time in several different time zones is disclosed. The timepiece may have a single clock unit, with several separate time displays being controlled by the single clock unit, in which case, the different times displayed in the different time zones result from a central display offset means. Or, the timepiece may have multiple clock units, the multiple units each having their own display, and being coordinated or set to display the time in the different time zones. In this case, the coordination or setting of the multiple clock units may be done by hand or automatically. Associated with each time display is a label to indicate the time zone or a location within the time zone for that display. Preferably, the labels are changeable so that the time zone or location indicated may be changed.

1. Field of the Invention
This invention relates generally to chronometers and timepieces, and more specifically to a timepiece which simultaneously displays the time in several different time zones.
2. Description of Related Art
Often it is convenient or necessary to know the time of day in several locations in different time zones. For example, an over-the-road trucker may want to know, without making mental calculations, the time at the company's headquarters in New York City, at the warehouse in Chicago, at the destination in Los Angeles, and at home in Denver. Likewise, a marketing executive in Tampa may want to know the time at the importer's office in Seattle, of one supplier's factory in Taipei, and at another supplier's factory in Moscow.
Therefore, there is a need for a timepiece which simultaneously displays the time in several different time zones. Also, there is a need for such a timepiece in which the different time zones are selectable.
U.S. Pat. No. 3,763,645 (Kim) discloses a rotary clock with a twelve-sectored dial attached to the same shaft as the hour hand. Stickers provided with the names of cities in other time zones may be placed on the respective sectors of the dial to indicate the time in the respective cities.
Likewise, U.S. Pat. Nos. 4,972,392 (Wang) and 5,107,468 (Lu) both disclose rotary clock faces which are adapted to display the time in several different time zones.
Still, there is a need for a timepiece which simultaneously displays the time in several different time zones, the time zones being specifically labeled so that no mental calculations are needed to determine the time in a time zone of interest.
This invention addresses this need.


An easily controllable primary drive (5) guided in a first bore (3), for example a piezo actuator, transmits its stroke by a piston-hydraulic stroke transmission with a hydraulic chamber (2) onto a stroke element (70) of the secondary side guided in a second bore (4). The pressure in a valve chamber (9) is controlled via the stroke element (7) of the secondary side.

The significance of a fast and precise control of valve systems is increasing with an increase demand for hydraulic systems. One example of such a field of activity is fuel injection, for example direct injection of diesel fuel into the combustion chamber of a motor. What is referred to as the "common rail" system wherein the fuel is conveyed from a central conveying pump into a filling conduit ("common rail") shared by all cylinders thereby has great potential. The dosing of the fuel ensues via a system for fuel injection that is individually allocated to each and every cylinder. The improvement of the motor operating behavior that can be achieved with the assistance of a common rail injection system thereby essentially results from an injection pressure of up to 2500 bar that can be regulated independently of the motor speed. Added thereto given this technology is the possibility of shaping the course of the injection, i.e. of generating a single or multiple pilot injection, or of the control of the injection rate as well as the free control of characteristics of start of injection and injected amount.
For realizing these advantages, the system for fuel injection must satisfy a very high dynamic demand; for example, it must exhibit a short drive dead time and a short switching time.
Up to now, the control of common rail injectors has essentially ensued with the assistance of a solenoid drive. In some instances, the injector is also controlled with the assistance of a piezo-hydraulic drive.
In the control of a fuel injector with the assistance of a piezoelectric direct drive for valve control of the hydraulic system, the problem arises, for example, that only an inadequate compensation of a change in length of piezo actuator and housing caused by temperature effects or by aging and settling effects is realized. Added thereto is that a piezo actuator having a large structural length is required given piezo direct drive, which is disadvantageous in terms of manufacturing technology and in view of the manufacturing costs.
Numerous problems such as, for example, an involved mechanical balancing, a risk of breaking the diaphragm and well as a low efficiency of the diaphragm-type hydraulics arise given a combination of the piezo actuator with a diaphragm-type hydraulics for valve control in the injection system. Also unsatisfactory are, for example, the influence of pressure waves, a problematical temperature compensation as well as a merely satisfactory switching behavior.
Another example for the employment of a fast valve control is the braking circulation of a vehicle, whereby the hydraulic pressure in an anti-blocking system must be regulated precisely and fast. The employment of a fast and precise valve control in the hydraulic circulation of an elevator control or, respectively, vertical rudder in an aircraft is also conceivable. The guidance rudder must thereby be driven very fast in order to assure the safety of the aircraft, particularly in modern aircraft designed aerodynamically unstable.


A method is performed at a server that manages embedded subscriber identity module (eSIM) profiles. The method includes, when a user equipment that belongs to a global enterprise network relocates from a first locale to a second locale in which a first private network and a second private network of the global enterprise network are located, wherein the user equipment includes a locale-specific first eSIM profile that includes a first non-public network identifier of the first private network, receiving, from the user equipment over a network in the second locale, information that indicates the user equipment is in the second locale. The method further includes identifying the second private network based on the information, and generating a locale-specific second eSIM profile that includes a second non-public network identifier for the second private network. The method includes configuring the user equipment with the locale-specific second eSIM profile.

User equipment (UE) (i.e., mobile device) support for roaming is a challenge for global enterprises managing private 3rd Generation Partnership Project (3GPP)/fifth generation (5G) networks. Such private networks are also referred to as "standalone non-public networks" (SNPNs) and, more generally, as "non-public networks" (NPNs). Frequency spectrum regulators in different regulatory domains are opening-up spectrum for private use. The spectrum sharing rules are locale-specific, and impose strict rules on how network identifiers (NIDs) for the NPNs are to be allocated and shared across different enterprises. For example, in the 3.5 GHz citizens broadband radio service (CBRS) band, there is a common public land mobile network (PLMN) identifier (ID) (e.g., 0310 015) and a unique NID that are allocated for each of the CBRS network operators. Together, the PLMN and NID set/pair identify an NPN, i.e., a private network. The same allocation is not expected to be used in another country, which is under a different regulatory domain. Therefore, a global enterprise network with private network branches in different countries may potentially end up with unique sets of network identifier allocation, e.g., PLMN ID and NID, on a per-location basis. Each unique set of network identifiers is thus "locale-specific."
A global enterprise customer having private network branches in different countries/regulatory domains has to manage all of the allocated network identifiers from all of the countries/regions to ensure that each UE belonging to the global enterprise has an embedded subscriber identity module (eSIM) profile with credentials for accessing the network branches, including the locale-specific network identifiers. Meaning, for example, a UE in San Jose needs to have the eSIM profile with the PLMN ID and NID allocation specific to the San Jose region, and allocations of network identifiers of all of the other regions. However, it is impractical to provision all of the network identifiers of the global enterprise (which may number in the hundreds, in some cases) into the eSIM profile of the UE. The consequence of having only a fixed local network identifier for a local private network in the eSIM profile of the UE is that the UE does not have support for roaming to another private network. Thus, an enterprise user visiting a branch in another region will not be able to connect to the private network of that region.

Auto-update and activation of locale-specific eSIM profile for a global enterprise user


A liquid crystal panel development method for a panel including first and second substrates and first and second electrodes with a display voltage applied to liquid crystal interposed therebetween. The method involves applying a voltage signal between the electrodes with an AC voltage component of amplitude Vac and a DC voltage component Vdc, changing Vac and Vdc to measure the range of optimal DC component variation ΔVdc, and determining a structure or material of the liquid crystal panel such that the range of optimal DC component variation ΔVdc becomes less than a given value. ΔVdc=|Vdcb —Vdcw|, where Vdcb is the Vdc value at the minimum range of transmittance variation when Vdc is changed with Vac being fixed for displaying black, and Vdcw is the Vdc value at the minimum range of transmittance variation when Vdc is changed with Vac being fixed for displaying white.

1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) panel capable of reducing a persistence degree and a development method thereof.
2. Description of the Related Art
Each of FIGS. 31 and 32 is a schematic sectional view showing a structure of one pixel of an LC panel. FIG. 31 shows a state where no voltage is applied, and FIG. 32 shows a state where a voltage is applied.
The LCD panel includes substrates 10 and 20 opposing to each other, and a sealed-in nematic liquid crystal 30 having an anisotropic dielectric positive constant. In the substrate 10, a flat electrode 12, a dielectric layer 13 and a vertically oriented layer 14 are formed on a face of a transparent insulating substrate 11, for example, a glass substrate, and on the other face thereof, a polarizer 15 is formed. In the substrate 20, a common electrode 23 is formed on one face of a transparent substrate 21, for example, a glass substrate, an insulating layer 24 is formed thereon, a pixel electrode 25 is formed on the insulating layer 24, and further an insulating layer 26 and a vertically orientated later 27 are formed thereon. On the other face of the substrate 21, a polarizer 28 is formed. Transmission axes of the polarizers 15 and 28 perpendicularly cross over each other.
When backlight in the direction shown by arrows in FIG. 31 enters into the LCD panel, the light is transformed into linearly polarized light by the polarizer 28. When the flat electrode 12, the common electrodes 23 and the pixel electrode have the same potential, the liquid crystal 30 effects no change in the plane of polarization of the linearly polarized light, and therefore the linearly polarized light cannot be transmitted through the polarizer 15, resulting in a dark state.
When, as shown in FIG. 32, the flat electrode 12 and the common electrode 23 has the same potential but the pixel electrode 25 is applied with a potential different from the both former electrodes, an electric field arises. Dotted lines of FIG. 32 show the lines of electric force. Liquid crystal molecules are inclined relative to an incident light direction under influence of the electric field to cause birefringence, and part of the light can transmit through the polarizer 15, resulting in a bright state.
Since the common electrode 23 and the pixel electrode 25 are made of an opaque metal, behaviors of liquid crystal molecules over the electrodes are not problematic in terms of display.
If the flat electrode 12 does not exist, liquid crystal molecules between the pixel electrode and the common electrode 23 tend to reduce inclination thereof, which will produces the drop region of transmittance. The flat electrode 12 makes the electric field between the common electrode 23 and the pixel electrode 25 asymmetric so as to contributes to prevent the transmittance from locally dropping. The dielectric layer 13 reinforces the lateral component of the electric field in the liquid crystal 30 to make it possible for the liquid crystal 30 to be driven with lower applied voltage. The common electrode 23 and the pixel electrode 25 each are stripe electrodes extending in the direction perpendicular to the sheet of FIG. 32, and alternately formed on the top and bottom surfaces of the insulting layer 24. The insulating layer 24 is for preventing common electrodes and pixel electrodes from short-circuiting at positions where the both overlap as will be described later. The insulating layer 26 is for reducing the persistence degree.
FIG. 33 shows an electrode pattern of one pixel, formed in the substrate 20 of FIG. 31. FIGS. 34 and 35 are patterns of the pixel electrode 25 and the common electrode 23, respectively, of FIG. 33.
In FIG. 33, a data line DL1 and a scan line SL1 cross over each other with an insulating layer interposing therebetween. Each of the pixel electrode 25 and the common electrode 23 has a stripe section and a peripheral section connecting ends of the stripe section. The lines of the stripe section are inclined 45 degrees to each of the scan line SL1 and the data line DL1.
When the potential of the scan line SL1 goes high, a TFT 29 is turned on to apply the potential of the data line DL1 onto the pixel electrode 25 and generate an electric field between the stripe electrodes of the pixel electrode 25 and the common electrode 23. The longitudinal direction of the upper half of the stripe electrodes is different from that of the lower half of the stripe electrodes by 90 degrees as shown in FIG. 33, whereby the LCD panel has wider range of viewing angles than in a case where the both halves of the stripe electrodes are parallel to each other.
The common electrode 23A has peripheral protrusions which are connected to the common electrodes of adjacent pixels not shown.
FIG. 36(A) is an enlarged partial view near a crossover of a stripe electrode and the peripheral section of FIG. 33. FIG. 36(B) shows the lines of electric force with dotted lines near the crossover when a voltage is applied between the pixel electrode 25 and the common electrode 23.
A peripheral section of the pixel or common electrode has crossover portions to stripe electrodes of the common or pixel electrodes with the insulating layer interposing therebetween since a pixel has a rectangular shape, and each of the pixel electrode 25 and the common electrode 23 has stripe electrodes in parallel to each other and has a continuous shape. For example, a side 251 of the pixel electrode 25 is connected to a side 252 of the peripheral section, and a side 231 of the common electrode 23 is parallel to the side 251, while the side 231 crosses over the side 252 at an acute angle.
FIG. 37 is a schematic sectional view showing inclination of liquid crystal molecules between the pixel electrode 25 and the common electrode 23 of one pixel of the LCD panel when a voltage is applied therebetween.
In FIG. 32, a structure between the pixel electrode 25 and the liquid crystal 30 is different from that between the common electrode 23 and the liquid crystal 30, which causes persistence.
In FIG. 36(B), since the side 252 crosses over the side 231 at an acute angle, an electric field therebetween near the crossover is stronger than that between the parallel sides. Further, a direction of electric field strength near the crossover is different from that between the parallel sides. Due to such conditions, a transmittance-voltage characteristic near the crossover is different from that between the parallel portion, causing not only degradation of an image quality but also persistence.
In FIG. 37, since the insulating layer 26 exists above the pixel electrode 25, application of an electric field in this portion is useless and effective application of the electric field to the liquid crystal 30 is prevented. If the insulating layer 26 is omitted in order to solve this problem, it causes more persistence since the insulating resistance of the vertically oriented layer 27 is low. If the pixel electrode 25 is exposed to the liquid crystal 30, not only is the degree of persistence enhanced, but liquid crystal molecules also decompose. Further, since the top surface of a pixel electrode 25 is flat, it is not possible to effectively apply an electric field to the liquid crystal 30 in relation to transmittance, which prevents achieving higher contrast display.
In development of an LCD panel, measurement of a persistence degree is performed at each trial when a structure or material of the LCD panel is changed in order to reduce the persistence degree to a value lower than a given value, and it takes, for example, 48 hours to measure the persistence degree in each trial, which makes a development term thereof longer.

Liquid crystal display panel development method


Gases evolved during photolithographic processing of chemically amplified photoresist systems are monitored to allow optimization of process parameters such as intensity and duration of applied heat or radiation. Specifically, during soft bake, evaporation of solvent gases is detected. During exposure and PEB, gases evolved during activation of the polymer resin component by the photoacid are detected. The intensity and/or duration of the heating or exposure are then varied to optimize resolution of the particular photolithography process. Residual gas analysis, diode laser spectroscopy, FT-IR spectroscopy, and electronic sensing may be utilized alone or in combination to monitor composition and/or concentration of evolved gases in accordance with the present invention.

1. Field of the Invention
The present invention relates to methods and apparatuses for controlling the reaction of photoresist during semiconductor fabrication processes, and, more particularly, to controlling the reaction of chemically-amplified photoresist by analyzing the concentration of gas evolved during soft baking, exposure, and/or post-exposure baking steps.
2. Description of the Related Art
Photoresist materials have long enjoyed widespread use in the field of semiconductor fabrication. One form of photoresist technology utilized in conjunction with deep UV lithography is known as chemically-amplified resist (CAR).
Chemically-amplified photoresist systems are generally composed of 1) a polymer resin and 2) a photoacid generator (PAG), and may also include 3) a crosslinking agent, dye, or other additive.
CAR photoresist systems generally operate in the following manner. A nonactivated polymer resin is initially combined with a photoacid generator. Exposure of the photoacid generator to deep UV radiation changes the photoacid generator into a photoacid. The photoacid then triggers an activation reaction involving the polymer resin.
In the case of a positive CAR photoresist system, the photoacid catalyzes the deprotection of blocking groups on the polymer resin, increasing the polarity of the resin and hence, its solubility in aqueous base. Thus, the activation reaction for a positive CAR photoresist converts a nonpolar, insoluble polymer resin into a polar, soluble polymer resin.
In the case of a negative CAR photoresist system, the photoacid reacts with a cross-linking agent to trigger cross-linking between adjacent polymer chains. Thus, the activation reaction for a negative CAR photoresist system converts a single-chain, soluble polymer resin into a cross-linked, insoluble polymer resin.
FIG. 1 illustrates the sequence of process steps typically utilized in a CAR system. During the first spin-coat step, the multi-component photoresist mixture within a solvent carrier is dispensed onto a silicon wafer surface as the wafer is rapidly spun. The solvent carrier is typically propylene glycol monomethyl ether acetate (pgmea). The wafer is spun until the solvent carrier is substantially removed and the mixture dries as a film of uniform thickness over the entire surface.
The second photolithography step utilized in a CAR system is the soft bake. During soft baking, additional remaining solvent carrier is removed from the spun-dried photoresist mixture. The photoresist coated wafer is heated to approximately the glass-transition temperature T.sub.g of the nonactivated resin, such that excess solvent is driven off and the photoresist hardens.
The third step in the CAR process is exposure of the dried photoresist mixture to deep UV radiation (typically 193 nm or 248 nm). The exposure step requires utilization of complex photolithography equipment and precise masking techniques in order to ensure precise application of radiation only to those portions of photoresist intended to be exposed.
The fourth step in a deep UV photolithography process is the post-exposure bake (PEB). During the PEB, the photoresist is again subjected to temperatures on the order of T.sub.g. Thermal energy applied to the photoresist during the PEB causes the photoacid to diffuse within the resin. The diffusion of the photoacid fully activates the polymer resin in regions exposed to deep UV light, and also dampens any standing wave effects at the edges of exposed photoresist regions.
The fifth step associated with the CAR process-sequence is development. During development, an aqueous base solution is added to the exposed and baked photoresist, and a portion of the resin dissolves. Depending upon whether the CAR system is positive or negative, either activated or nonactivated polymer resin is dissolved in the aqueous base and removed.
After CAR photolithographic processing, the carefully created photoresist pattern serves to selectively mask etching of the silicon to form semiconducting structures having extremely precise shapes and sizes.
FIG. 2 illustrates the chemical reaction sequence of one exemplary positive CAR system. In the reaction sequence shown in FIG. 2, a photoacid generator consisting of triphenyl sulfonium salt 2 of trifluoroacetic acid is introduced into a mixture of nonpolar, aqueous base insoluble t-butoxycarbonyl (t-BOC)-substituted styrene 4 within a solvent consisting of pgmea. Exposing salt 2 to deep UV radiation causes disassociation of the triphenyl sulfonium to produce the photoacid trifluoroacetic acid 6.
Trifluoroacetic acid 6 then causes conversion of the nonpolar t-BOC group of styrene 4 into a polar hydroxy group. Subsequent heating of the mixture during a PEB step further enhances the rate of the conversion reaction. The resulting polyhydroxystyrene 8 is very polar.
Polyhydroxystyrene 8 present in photoresist regions exposed to deep UV radiation can be readily removed by dissolution in an aqueous base solution during the development step, to yield the desired pattern of photoresist.
Carbon dioxide 12 and isobutene 10 are side products of the conversion reaction of t-BOC substituted styrene 4 into polyhydroxystyrene 8. Both carbon dioxide 12 and isobutene 10 are volatile gases that diffuse into the air above the surface of the photoresist-coated wafer as activation reaction of the polymer resin proceeds to completion.
One limitation of current CAR processes is the difficulty in monitoring the amount of the solvent carrier and other materials driven from the spin coated wafer during the soft bake step. Overheating the photoresist mixture during the soft bake can cause degradation in the polymer resin or the PAG, hampering subsequent steps in the process.
On the other hand, underheating the photoresist mixture during the soft bake can result in excessive solvent remaining in the mixture. Excess solvent can cause problems during subsequent steps by altering the rate of generation of acid by the PAG, and/or by altering the rate of activation of the polymer by the acid.
Therefore, it is desirable to design methods and apparatuses that allow the extent of removal of solvent from a CAR coated photoresist wafer to be monitored and controlled during the soft bake step.
Another limitation in current CAR processes is that photoacid catalyzed conversion of the polymer resin cannot readily be monitored during the exposure or PEB steps.
Depending upon the CAR photoresist system utilized, activation of the polymer resin can occur predominantly either during the exposure step or the PEB step. Some CAR photoresist systems, such as the T-Boc protected polymer described above, are high activation energy systems. This means that even after H.sup.+ is generated by the PAG during exposure, additional thermal energy is required to initiate activation. This thermal energy is provided by the PEB step.
Other CAR photoresist systems, such as those utilizing acetal protection, are low activation energy systems. This means that once H.sup.+ is generated during exposure by the PAG, significant activation of the polymer resin takes place even in the absence of additional thermal energy.
With either high or low activation energy type systems, inability to ascertain the extent of activation of the polymer resin can create serious problems during subsequent development. For example, overexposing the wafer or overheating during PEB can result in excessive diffusion of the photoacid, causing the photoacid to migrate out of exposed regions of the photoresist into outlying, unexposed regions of the photoresist. Such excessive diffusion of the photoacid effectively degrades the resolution of the exposure. Excessive heating during PEB can also trigger unwanted cross-linking of the polymer resin, or deprotection of resin in locations not exposed to UV radiation. The above referenced phenomena create problems both in absolute terms, and in terms of maintaining consistency of critical dimension (CD) linewidth between different lots of wafers.
On the other hand, underexposing the wafer or underheating during PEB can produce excessively limited diffusion of the photoacid, causing inadequate activation of the polymer resin in exposed regions of the photoresist mixture. This can result in either too much or too little photoresist remaining after development, again adversely affecting the CD linewidth of etched features.
Therefore, it is desirable to design methods and apparatuses that allow activation of the polymer resin component of a CAR system to be monitored during the exposure and PEB steps.

Chemical gas analysis during processing of chemically amplified photoresist systems


A snow ski binding is provided that includes a boot plate which is releasably securable to a ski by a toe piece and heel piece. The boot plate is pivotally connected to the toe piece so as to selectively pivot about a transverse axis and allow a skier to move in a cross-country motion. The heel piece is movable between a plurality of positions to selectively lock the trailing end of the boot plate to the ski to facilitate downhill skiing or can be repositioned to allow the boot plate to pivot about the toe piece while restricting the downward movement of the trailing end of the boot plate between two locations to facilitate use of the binding in a cross-country mode for climbing hills.

1. Field of the Invention
The present invention relates generally to bindings for snow skis and more particularly to a binding which is convertible between downhill and cross-country use.
2. Description of the Prior Art
Ski bindings have evolved from a very crude form wherein a strap was used to secure the skier's boot to the ski to more sophisticated bindings which automatically release the skier from the ski once certain relative forces are applied to the skier or ski. These latter bindings have been referred to as safety release bindings and are intended to minimize the risk of injury to the skier. Release bindings have primarily been directed toward Alpine or downhill skiing and have rarely addressed cross-country skiing.
Cross-country skiing has been rapidly increasing in popularity. For years, bindings for cross-country skiing did not vary materially and most have utilized some form of anchor for the toe of the skier's boot while leaving the heel free to lift as occurs in normal walking motions.
The recent increase of interest in cross-country skiing, however, has brought about a need for a binding which is readily convertible between use as a downhill skiing release binding and a cross-country binding. Examples of such bindings can be found in U.S. Pat. No. 4,002,354 issued Jan. 11, 1977 to Paul C. Ramer for SKI BINDING; U.S. Pat. No. 2,686,059 issued Aug. 10, 1954 to Francis Whitaker for SKI HARNESS; U.S. Pat. No. 4,513,988 issued Apr. 30, 1985 to Josef Svoboda for a DEVICE FOR CROSS-COUNTRY SKIING; U.S. Pat. No. 4,392,666 issued Jul. 12, 1983 to Paul C. Ramer for INTEGRAL SKI BINDING; U.S. Pat. No. 4,500,108 issued Feb. 19, 1985 to Luvern Johnson, III, for CONVERTIBLE SKI DEVICE; and French Patent No. 2,490,099 published Mar. 19, 1982.


A BGA package including a substrate, a plurality of solder balls on the semiconductor and an encapsulant, which leaves the solder balls partially exposed on the semiconductor chip, thereby reducing the size of the BGA package. In addition, an edge of the substrate may extend beyond an edge of the semiconductor chip. Stacked BGA packages and methods of manufacturing a BGA (or stacked BGA) package are also disclosed.

1. Field of the Invention
The present invention relates generally to semiconductor packages and methods for manufacturing the same. More particularly, the present invention relates to ball grid array (BGA) packages, stacked BGA packages having a plurality of BGA packages, and methods for manufacturing the same.
2. Description of the Related Art
In general, semiconductor wafers are subjected to deposition, etching, planarization and/or lithographic processes. The wafer may then be diced using scribe lines to form multiple semiconductor chips. The semiconductor chips may be mounted onto printed circuit boards (PCBs) or other mounting substrates, utilizing various packaging methods.
As a result of developments in electrical products, semiconductor packages are becoming more highly integrated to reduce the size and/or thickness. In order to increase the number of semiconductor chips on a limited mounting area, chip scale packages (CSPs) have been generally adopted in semiconductor packages. The mounting area of CSPs may be smaller than other packages, because the extent of a CSP, i.e., the area being multiplied width by length, compared to the semiconductor chip may be less than the ratio of 1:1.2. Types of CSPs, such as ball grid array (BGA) packages, including semiconductor device packages, are known.
FIG. 1 is a cross-sectional view of a conventional wire bonding BGA (WBGA) package. Referring to FIG. 1, a semiconductor chip 5 with a plurality of bonding pads 10 may be attached on the top of a substrate 20 by an adhesive layer 15. The plurality of bonding pads 10 and the substrate 20 including a plurality of metal landing pads (not shown) may be connected by a series of bonding wires 25. An encapsulant 45 may be utilized to cover the semiconductor chip 5 and the series of bonding wires 25. A solder mask 35 may be formed on the substrate 20 and a plurality of solder balls 40 may be placed on the corresponding solder ball pads (not shown) on an opposite side of the semiconductor chip 5. The plurality of solder balls 40 may be attached after the encapsulant 45 is added.
In order to mount a plurality of semiconductor chips in a limited area, stacking technology for manufacturing multiple semiconductor packages has been adopted. Accordingly, each unit BGA package for the stackable package has a thickness profile. Further, in order to attach solder balls on the top of the semiconductor chip, either additional patterning processes or boards may be needed.

Ball grid array package, stacked semiconductor package and method for manufacturing the same


A high capacity filter apparatus for removing solids from fluids includes a opposing filter elements defining an internal volume. Fluid to be filtered passes through the filter elements into the internal volume and through an outlet. The filter element is continuously cleaned by backwashing along the outer surface of the elements.

The present invention relates to a continuous backwashing filter apparatus for separating particulate matter from a fluid medium. The continuous backwashing feature enables continuous filtering of high volumes of a fluid medium containing gaseous matter or particles having a broad particle size distribution, including ultrafine particles having a particle size below, for example, 1 .mu.m.
Conventional filter arrangements have been known wherein a backwash device is provided proximate an inlet side of a filter element in the filter arrangement. For instance, U.S. Pat. No. 4,085,051, to Kaminsky et al, discloses a self-cleaning filter for separating solid particles from a liquid wherein a device for backwashing the filter element abuts the filter element and is rotated about a central shaft such that the filter element can be backwashed of any accumulated particles. However, the backwashing function requires a pressure differential between an inlet chamber and an outlet chamber of the filter apparatus due to the buildup of particulate matter on the inlet side of the filter element.
The creation of that necessary pressure differential requires the presence of a substantial amount of filtered fluid in the outlet chamber. Stated differently, filtered fluid must be present at an outlet side of the filter to provide a liquid medium passing in a reverse direction through the filter to transport the particulate matter off of the inlet side of the filter and into the backwashing device. However, such filtered fluid is not always present at the outlet side in the device of Kaminsky et al. When filtering fluids having particles of a broad particle size distribution, it is inevitable that the filter element will become clogged before there is a sufficient amount of filtered fluid in the outlet chamber to facilitate the backwashing function.
U.S. Pat. No. 3,635,348, to Carr, discloses an automatic self-cleaning strainer which provides a backwash device in abutted contact with an inlet side of a filter element in the strainer. The filter element is shaped like a truncated cone and the shape of the contacting surface of the backwash device is complimentary to the inlet side of the filter element. The backwash device is retractable along a central axis of the filter element to facilitate sequential radial movement of the backwash device within the filter element. This strainer apparatus cannot provide continuous backwashing due to the sequential action of the backwash device. As a result, the efficiency of the strainer apparatus is degraded.
The strainer of the Carr apparatus also suffers from the problem encountered in the filter apparatus of Kaminsky et al in that the backwashing function is contingent upon whether the outlet chamber is filled with filtered fluid, i.e., whether filtered fluid is present proximate an outlet side of the filter element. Accordingly, the strainer apparatus of Carr cannot filter fluid mediums having a broad particle size distribution including ultrafine particles, since it is inevitable that the filter element will become clogged before the outlet chamber is filled with filtered fluid to facilitate the backwashing function.
U.S. Pat. No. 3,640,395, to Kinney, discloses an automatic self-cleaning strainer having a plurality of filter stages including backwash devices in loose contact with an inlet side of the filter element of each filtering stage. Each of the backwashing devices is in communication with a hollow shaft which is open to the atmosphere. However, before the backwashing function will occur, filtered fluid must be present in the outlet chambers of each filtering stage. Therefore, the strainer apparatus cannot filter a fluid medium which contains large amounts of particulate matter including ultrafine particles, since the filter element in each stage will become clogged before the outlet chambers are filled with filtered fluid to facilitate the backwashing function.
U.S. Pat. No. 3,669,269, to Kinney, discloses a filter apparatus having a rotating cylindrical strainer element and a stationary backwash chamber in contact with an inlet side of the strainer element. However, in the device of Kinney '269, as in the other prior art devices, the outlet chamber within the strainer element must be substantially full of filtered fluid before the backwashing function will occur, which does not necessarily always happen. Thus, this strainer apparatus suffers from the same problems as discussed above.
The inventor's prior U.S. Pat. No. 5,128,029 (Herrmann '029) relates to a continuous backwashing filter apparatus with a filtered fluid retention plate. In this apparatus, a sliding shoe containing a slit contacts a perforated plate placed over a filter medium on the inlet side, and removes particles from the medium by backwashing with a reservoir of filtered liquid retained on a retention plate on the outlet side of the filter media.
Backwashing occurs because the pressure in the sliding shoe is less than in the outlet side of the filter. The retention plate is critical to the function of this apparatus, since it provides the constant supply of filtered fluid necessary for constant backwashing. This arrangement, while functional, has several drawbacks.
One drawback is the size limitation of the filter imposed by the sliding shoe/retention plate arrangement. The sliding shoe must be sealed from the unfiltered fluid on the inlet side. If this seal is broken, unfiltered fluid under high pressure will leak into the sliding shoe, and be removed with the backwash, essentially "short circuiting" the filter. This places severe limits on the maximum size and capacity of the filter. For example, filtration of a liquid having a high level of total suspended solids (TSS) with a filter media having a nominal pore size of 10 .mu.m or less results in very limited filter capacity. This is because a very high differential pressure is necessary to maintain a high flow rate under these conditions. Under such high pressure, the perforated plate above the filter media is forced against the sliding shoe and the backwash function is disabled.
If the size of the filter is increased to provide greater capacity, the contact area between the sliding shoe and the filter media can flex, resulting again in leakage and short circuiting of the filter. Likewise, installing two or more filters in parallel is generally difficult, since the structure of the backwashing function does not lend itself to parallel connection of multiple units.
A second drawback of the inventor's prior design is that, in some embodiments, the retention plate must be maintained horizontally level for proper backwashing, and hence installation of the backwashing filter apparatus is limited to an upright position.
Thus, despite the improvements in filtration afforded by the Herrmann '029 patent, there remains a need in the art for a filter apparatus which can filter very small particles at high capacity, can be installed in any position, and which can be easily expanded to provide further increases in capacity when necessary, and further eliminates the possiblity of leakage.
Sewage treatment is one area in which filtration of small particles at high capacity would be useful. In conventional biological treatment systems, particulates in the wastewater isolate the available oxygen necessary for microbe growth, resulting in delay or elimination of biological breakdown of waste material. An apparatus suitable for ultrafiltration at the high capacities needed for wastewater treatment would greatly expand the capacity and quality of discharge in existing treatment plants and/or reduce the size and complexity of equipment needed for treating a given quantity of sewage.