A new gamma-ray stabilizer comprising a combination of 100 parts by weight of a benzyl compound (A) having a specific chemical structure and 0.01 to 10 parts by weight of a pentaerythritol phosphorous ester (B) having a spirocyclic structure. Said stabilizer is preferably blended in such a manner that said (A) is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of a thermoplastic polymer (polycarbonate or the like), and said (B) is contained in an amount of 0.01 to 1 part by weight based on 100 parts by weight of said (A). When the thermoplastic polymer is subjected to gamma-ray irradiation, said stabilizer can efficiently protect the thermoplastic polymer from the deterioration of physical properties and yellowing; and on molding processing, the stabilizer-added polymer is suffered from little color tone deterioration and has excellent color tone, and at the same time, the polymer is scarcely suffered from molecular weight decrease on molding, and exhibits excellent thermal stability, moldability or the like. The thermoplastic polymer (especially polycarbonate) composition containing said stabilizer thus obtained is suitable for medical apparatus and medical material uses, especially a jacket case for an artificial dialyzer.

This application is a 371 of PCT/JP99/03111, filed Jun. 10, 1998.
The present invention relates to a new gamma-ray stabilizer and a thermoplastic polymer composition containing said stabilizer. More specifically the present invention is concerned with a new gamma-ray stabilizer having following advantages: the stabilizer can effectively protect a thermoplastic polymer (hereinafter referred to as xe2x80x9cthermoplastic resinxe2x80x9d in some cases or a molded product thereof against properties deterioration and yellowing when the thermoplastic polymer or the molded product undergoes gamma-ray irradiation; the incidences of decomposition reaction, foreign matter formation and color tone deterioration are few on molding processing of a thermoplastic resin which has been compounded with said gamma-ray stabilizer; and further the incidences of such various defects are also low in the molded product formed from the composition containing said gamma-ray stabilizer. The present invention is also concerned with a thermoplastic resin composition containing said gamma-ray stabilizer in a specific amount; and a molded product formed from said composition.
Medical apparatuses and supplies which are made of aromatic polyearbonate (hereinafter referred to simply as xe2x80x9cpolycarbonatexe2x80x9d) and many other thermoplastic resins are extensively used in the field of medical care. For example, because polycarbonate is a thermoplastic polymer having excellent characteristics in transparency, sanitation, dimensional stability, strength against impact, heat resistance and others, it is used for producing packaging materials for syringes and surgical instruments, artificial organs such as artificial lungs and kidneys, and various medical apparatuses such as surgical instruments and medical operation devices.
One of the most important required performances in such medical applications is the stability against various sterilization treatments. One of these sterilization methods is sterilization by gamma-ray irradiation. Compared with the conventional treatment by ethylene oxide or treatment by steam in an autoclave, this method provides less expensive dry sterilization at a lower temperature, and has come to find a wide application in recent years.
However, for example, when polycarbonate or its molded product is sterilized by gamma-ray irradiation, inherent transparence and clarity of the polycarbonate are extremely damaged, and the polycarbonate is yellowed and discolored in such a degree that the user feels uncomfortable; this problem is yet to be solved.
Many additives have been studied so far to prevent yellowing of the thermoplastic resin or molded products thereof due to gamma-ray irradiation For example, use of an alcohol such as aliphatic diol or polyol, a hindered phenol, or the like is disclosed in JP-A 60-192759 (JP-A means Japanese unexamined patent publication), while the use of a polyol such as polypropylene glycol is disclosed in JP-A 62-135556. Furthermore, the use of a specific polycarboxylic acid or acetal of benzaldehyde is mentioned in JP-A 2-132147. In addition, it is reported that an epoxy compound, a sulfur-containing compound, a boron compound and so forth have the effect of preventing yellowing due to gamma-ray irradiation.
However, these additives have problems as follows: a thermoplastic resin (e.g. polycarbonate) composition to which such a compound has been added does not have sufficient yellowing preventive effect; the properties of the resin composition are deteriorated when a sufficient amount of the compound is added for ensuring satisfactory effects; and the method of the addition to the thermoplastic resin is restricted due to the lack of sufficient heat resistance of the additive itself. Furthermore, there are other problems, that is, depending on the compound, when the gamma-ray irradiation is performed in a deoxygenated atmosphere, the same level of yellowing preventing effect as in the air cannot be achieved; or conversely, when gamma-ray irradiation is performed in the air, the yellowing preventing effect is small.
On the other hand, a method of using an organic halogen compound as a gamma-ray stabilizer is also known. For example, a method of using a bromine compound such as a tetrabromobisphenol A-type polycarbonate oligomer is disclosed in JP-A 2-129261, and a method of using a, nuclear bromine-substituted phthalic acid derivative is disclosed in JP-A 5-179127. Further, JP-A 5-214233 describes polyol compounds having halogen-substituted phenyl structures as a terminal group. These methods of using halogen compounds provide effective means for preventing yellowing whether gamma-ray irradiation is carried out in the air or in a deoxygenated atmosphere; however, these methods have disadvantages that environmental pollution problems arise when the resins containing the halogen compound or the products manufactured therefrom are discarded because of halogen atoms contained therein.
Furthermore, JP-A 5-132552 discloses the use of a polycarbonate which contains a p-hydroxybenzyl alcohol having hydrocarbyl group or hydrocarbyloxy group as an end cap agent. However, the production of this end capped polycarbonate resin requires a complicated manufacturing process, and the physical properties of the polymer itself are lowered by the use of a large amount of the end cap agent in order to enhance the yellowing prevention effect; these problems remain to be solved.
In addition, JP-A 8-225732 and European Patent Publication No. 384110 disclose compositions containing a benzyl compound as a gamma-ray stabilizer.
The composition containing a gamma-ray stabilizer of a prior art exhibits some effect in the prevention of yellowing of a thermoplastic resin (polyearbonate) caused by gamma-ray irradiation; however, when a molded product is produced by using such a composition, defects such as foaming, the occurrence of turbid spots or the generation of black foreign matters will appear in the molded products if molding is continued for a long period of time, for example, one to two days.
Especially, when an injection molding machine, which has been developed to improve the production efficiency of molded products, particularly a hot runner-type molding machine is used, the above-mentioned defects become more extreme.
The first object of the present invention is to provide a new gamma-ray stabilizer having the following advantages when added to a thermoplastic resin or a molded product thereof:
1) yellowing caused by gamma-ray irradiation during sterilization process is extremely little,
2) no lowering of physical properties nor generation of defects are observed on molding processing,
3) no deterioration of hue is detected even when the resin is held at a high temperature on molding processing,
4) the elution of the stabilizer is not observed at a steam treatment,
5) there are no problems when discarded, and so forth,
and thereby capable of giving a thermoplastic resin composition useful for medical apparatuses, medical supplies and medical materials.
The second object of the present invention is to provide a highly stable thermoplastic polymer composition containing said new gamma-ray stabilizer.
The third object of the present invention is to provide a polycarbonate molded product prepared by injection molding from said composition.
The fourth object of the present invention is to provide medical materials, especially a molded product of a jacket case for an artificial dialyzer which is prepared by injection molding from the said highly stable thermoplastic polymer composition.
Still further objects of the present invention will become clear from the following descriptions.
The present inventors zealously pursued investigations to solve said problems and found that, when at least one kind of benzyl compound (A) having a specific chemical structure is compounded with at least one kind of pentaerythritol phosphorous ester (B) having a spirocyclic structure at a specific quantitative ratio, and the obtained mixture is blended to a thermoplastic resin, it is possible to effectively provide a thermoplastic resin composition and a molded product thereof having high stability against gamma-ray irradiation for sterilization, and free from the deterioration of hue and little suffered from the generation of defects on molding processing owing to the synergistic effect of the combination of said components (A) and (B); and we have completed the present invention.
That is, the first of the present inventions is, a new gamma-ray stabilizer characterized in that the stabilizer comprises substantially a benzyl compound (A) selected from the group consisting of the compounds expressed by the following general formulae (1), (2)and (3)
[wherein, R1 to R11 are each independently selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 5 carbon atoms, cycloalkyl groups having 5 to 6 carbon atoms and aryl groups having 6 to 10 carbon atoms; Ar1, Ar3, Ar4, Ar5 and Ar6 are each independently, may have one or more substituents, monovalent aromatic groups having 6 to 20 carbon atoms; Ar2 is, may have one or more substituents,,a divalent aromatic group having 6 to 20 carbon atoms; p is 0 or 1; X is a direct bonding or a n-valent organic group having 1 to 20 carbon atoms, which may have one or more substituents; n is one of the integers 1 through 5], and a pentaerythritol phosphorous ester (B) having a spirocyclic structure; and the ratio of both the compounds is in the range of 0.01 to 10 parts by weight of said phosphorous ester (B) based on 100 parts by weight of said benzyl compound (A).
The second of the present inventions is a new resin composition having an excellent resistance to gamma-ray irradiation and characterized in that 100 parts by weight of a thermoplastic polymer, polycarbonate in particular, is compounded with 0.01 to 10 parts by weight of said benzyl compound (A) and said phosphorous ester (B), and the mount of the phosphorous ester (B) is in the range of 0.01 to 1 part by weight based on 100 parts by weight of the component A.
The third of the present inventions is an injection molded product made of said polycarbonate resin composition and having little deterioration in color tone on molding processing.
The fourth of the present invention is a polycarbonate composition having little lowering of physical properties and yellowing caused by gamma-ray irradiation and useful for a medical material, especially preferably a jacket case, for an artificial dialyzer, which is sterilized by gamma-ray irradiation.
The gamma-ray stabilizer of the present invention substantially comprises a benzyl compound (A) having a specific chemical structure and a phosphorous ester (B) having a specific chemical structure. The following are specific descriptions for each component.
The benzyl compound (A) is selected from the group consisting of benzyl ether compounds (A)-1, benzyl ester compounds (A)-2 and benzyl carbonate compounds (A)-3, and it can be used singly or in combination of two or more kinds. Hereafter, each compound is described in detail.
(A) -1: Benzyl Ether Compound
The benzyl ether compound (A)-1 constituting: the gamma-ray stabilizer of the present invention is expressed by the following general formula (1):
(wherein R1 to R7 are each independently selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 5 carbon atoms, cycloalkyl groups having 5 to 6 carbon atoms and aryl groups having 6 to 10 carbon atoms; Ar1 and Ar3 are, each independently and may have one or more substituents, monovalent aromatic group having 6 to 20 carbon atoms; Ar2 is, may have one or more substituents, a divalent aromatic group having 6 to 20 carbon atoms; p is 0 or 1)..
Examples of the alkyl groups RI to R7 include methyl, ethyl and butyl groups and the like. Examples of the cycloalkyl groups include cyclopentyl and cyclohexyl groups. Examples of the aryl groups include phenyl group and the like.
In the benzyl ether compound of the present invention, all groups of R1 to R7 are preferably hydrogen atoms.
When said aromatic groups are not substituted, examples of Ar1 and Ar3 include phenyl and naphthyl groups, and examples of Ar2 include phenylene and naphthylene groups. Further, when said aromatic group(s) are substituted, examples of the substituent(s) include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl and hexyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkoxy groups such as methoxy and ethoxy groups; acyloxy groups such as acetoxy and propionyloxy groups; aralkyl groups such as benzyl group; alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl groups; aromatic groups such as phenyl, tolyl and naphthyl groups; acyl groups such as acetyl and benzoyl groups; cyano, nitro and carboxyl groups, halogen atoms such as chlorine and bromine atoms; hydroxymethyl group; and the like.
Furthermore, from the view point of gamma-ray stability, the molecular weight of the benzyl ether compound expressed by the above formula (1) is preferably not more than 1000. More preferably the molecular weight of said compound is not more than 500, especially preferably not more than 300. That is, the benzyl compound expressed by the following formula (1)-1:
[wherein, R1xe2x80x2 and R6xe2x80x2 are each independently selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 5 carbon atoms, cycloalkyl groups having 5 to 6 carbon atoms and aryl groups having 6 to 10 carbon atoms; Ar1xe2x80x2 and Ar3xe2x80x2 are each independently, may have one or more substituents, monovalent aromatic groups having, 6 to 20 carbon atoms] corresponding formula (1) where p=0 is preferred.
Specific examples of the above formula (1) include the following compounds.
In the case of p=0, those are dibenzyl ether, di(naphthylmethyl) ether, benzyl (naphthylmethyl) ether, benzyl (xcex1-methylbenzyl) ether, benzyl (o-methylbenzyl) ether, benzyl (m-methylbenzyl) ether, benzyl p-methylbenzyl) ether, benzyl (o-methoxybenzyl) ether, benzyl (m-methoxybenzyl) ether, benzyl .-methoxybenzyl) ether, benzyl (o-acetoxybenzyl) ether, benzyl (m-acetoxybenzyl) ether, benzyl (p-acetoxybenzyl) ether, benzyl (o-benzylbenzyl) ether, benzyl (m-benzylbenzyl) ether, benzyl (p-benzylbenzyl) ether, benzyl (o-methoxycarbonylbenzyl) ether, benzyl(m-methoxycarbonylbenzyl) ether, benzyl (p-methoxycarbonylbenzyl) ether, benzyl (o-phenylbenzyl) ether, benzyl (m-phenylbenzyl) ether, benzyl (p-phenylbenzyl) ether, benzyl (o-acetylbenzyl) ether, benzyl (m-acetylbenzyl) ether, benzyl (p-acetylbenzyl) ether, benzyl (o-cyanobenzyl) ether, benzyl (m-cyanobenzyl) ether, benzyl (-cyanobenzyl) ether, benzyl (o-nitrobenzyl) ether, benzyl (m-nitrobenzyl) ether, benzyl (c-nitrobenzyl) ether, benzyl (o-bromobenzyl) ether, benzyl (p-bromobenzyl) ether, benzyl (m-bromobenzyl) ether, bis(o-methoxybenzyl) ether, bis(m-methoxybenzyl) ether, bis(p-methoxybenzyl) ether, bis(o-methylbenzyl) ether, bis(m-methylbenzyl) ether, bis(p-methylbenzyl) ether, bis(o-acetoxybenzyl) ether, bis(m-acetoxybenzyl) ether, bis(p-acetoxybenzyl) ether, bis(o-benzylbenzyl) ether, bis(m-benzylbenzyl) ether, bis(p-benzylbenzyl) ether, bis(o-methoxycarbonylbenzyl) ether, bis(m-methoxycarbonylbenzyl) ether, bis-(p-methoxycarbonylbenzyl) ether, bis(o-phenylbenzyl) ether, bis(m-phenylbenzyl) ether, bis(p-phenylbenzyl) ether, bis(o-acetylbenzyl) ether, bis(m-acetylbenzyl) ether, bis(p-acetylbenzyl) ether, bis(o-cyanobenzyl) ether, bis(m-cyanobenzyl) ether, bis(p-cyanobenzyl) ether, bis(o-nitrobenzyl) ether, bis(m-nitrobenzyl) ether, bis(p-nitrobenzyl) ether, bis(o-bromobenzyl) ether, bis(m-bromobenzyl) ether, bis(p-bromobenzyl) ether, bis(xcex1-methylbenzyl) ether, bis(p-hydroxymethylbenzyl) ether, bis(m-hydroxymethylbenzyl) ether, and bis(o-hydroxymethylbenzyl) ether and the like.
Among them, bisbenzyl ether is preferred.
In the case of p=1, compounds as expressed in the following formulae (herein, Me expresses a methyl group) can be given as examples:
The above-mentioned benzyl ether compounds (A)-1 can be used singly or in combination of two or more kinds.
(A)-2: Benzyl Ester Compound
The benzyl ester compound (A)-2 constituting the gamma-ray stabilizer of the present invention is expressed by the following formula (2):
(in the formula (2), R8 is selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 5 to 20 carbon atoms and aryl groups having 6 to 20 carbon atoms; Ar4 is, may have one or more substituents, an aryl group having 6 to 20 carbon atoms; X is a direct bond or a n-valent organic group having 1 to 20 carbon atoms, which may have one or more substituents; n is one of the integers 1 through 5).
In the formula (2), R8 is selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 20 (preferably 1 to 5) carbon atoms; cycloalkyl groups having 5 to 20 (preferably 5 to 6) carbon atoms and aryl groups having 6 to 20 (preferably 6 to 10) carbon atoms. Here, examples of the alkyl groups include methyl, ethyl and butyl groups; examples of the cycloalkyl groups include cyclopentyl and cyclohexyl groups; and examples of the aryl groups include phenyl group. Especially preferred is. the case where R8 is a hydrogen atom.
Ar4 is , may have one or more substituents, aryl group having 6 to (preferably 6 to 10) carbon atoms. When said aryl group is not substituted, examples of Ar4 include phenyl and naphthyl groups. When said aryl group has a substituent on the aromatic ring, examples of the substituent include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl and hexyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkoxy groups such as methoxy and ethoxy groups; acyloxy groups such as acetoxy and propionyloxy groups; aralkyl groups such as benzyl group; alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl groups; aryl groups such as phenyl, tolyl and naphthyl groups; acyl groups such as acetyl and benzoyl groups; halogen atoms such as chlorine and bromine atoms; and cyano, nitro, carboxyl and hydroxymethyl groups.
Further, X in the formula (2) is a direct bond or, may have one or more substituents, n-valent organic group having 1 to 20 (preferably 1 to 10) carbon atoms. Examples of such an organic group include aliphatic residues having 1 to 20 (preferably 1 to 10) carbon atoms, and alicyclic or aromatic residues having 6 to 20 (preferably 6 to 10) carbon atoms. The residues may have one or more substituents. Furthermore, n is one of the integers 1 through 5, and it is desirable to use a compound having n in this range as said benzyl ester compound.
Furthermore, from the view point of gamma-ray stability, the molecular weight of the benzyl ester compound expressed by the above formula (2) is preferably not more than 1000; the molecular weight of said compound is more preferably from 110 to 500.
Examples of the benzyl ester compound preferred in the present invention includes the following compounds:
Examples of the benzyl ester compound in which X is an organic group and n=1 in the above formula (2) include benzyl formate, o-methylbenzyl formate, p-methoxybenzyl formate, m-ethoxybenzyl formate, m-phenoxybenzyl formate, o-acetoxybenzyl formate, m-benzylbenzyl formate, o-methoxycarbonylbenzyl formate, o-benzoylbenzyl formate, p-cyanobenzyl formate, 2,6-dimethylbenzyl formate, p-methoxycarbonylbenzyl formate, methylnaphthyl acetate, xcex1-butylbenzyl acetate, o-methoxycarbonylbenzyl acetate, p-ethoxycarbonylbenzyl acetate, m-butoxycarbonylbenzyl acetate, o-phenylbenzyl acetate, 2,4,6-trimethylbenzyl acetate, 4-t-butylbenzyl acetate, m-propionylbenzyl acetate, p-cyanobenzyl acetate, p-fluorobenzyl acetate, benzyl propionate, o-decylbenzyl propionate, m-cyclohexyloxybenzyl propionate, o-heptoxycarbonylbenzyl propionate, p-phenylbenzyl propionate, p-lauroylbenzyl propionate, a -methylbenzyl butyrate, benzyl butyrate, p-cyclohexylbenzyl butyrate, m-butylbenzyl butyrate, 2,4-dimethylbenzyl butyrate, o-ethoxybenzyl butyrate, m-methoxycarbonylbenzyl butyrate, 2,6-dichlorobenzyl butyrate, 2,4,6-trifluorobenzyl butyrate, m-methylbenzyl octoate, p-butylbenzyl octoate, m-cyclohexylbenzyl octoate, o-cyanobenzyl octanoate, p-benzoylbenzyl octanoate, o-cyclohexyloxybenzyl octanoate, 2,3-dichlorobenzyl octanoate, o-methylbenzyl decanoate, m-ethylbenzyl decanoate, 2,3-dimethylbenzyl decanoate, 2,4,6-trimethylbenzyl decanoate, o-phenylbenzyl decanoate, m-t-butylbenzyl decanoate, 2, 4-di-t-butylbenzyl decanoate, m-butoxycarbonylbenzyl decanoate, p-acetylbenzyl decanoate, p-methoxycarbonylbenzyl decanoate, xcex1-ethylbenzyl decanoate, benzyl dodecanoate, benzyl hexadecanoate, p-butylbenzyl hexadecanoate, benzyl cyclohexanecarboxylate, m-methylbenzyl cyclohexanecarboxylate, 2,3-dimethylbenzyl cyclohexanecarboxylate, o-butoxybenzyl methylcyclohexanecarboxylate, benzyl cyclopentanecarboxylate, p-methoxycarbonylbenzyl cyclopentanecarboxylate, benzyl benzoate, benzyl m-methylbenzoate, p-ethylbenzyl p-ethylbenzoate, o-methoxybenzyl benzoate, p-acetoxybenzyl benzoate, m-methoxycarbonylbenzyl benzoate, p-butoxycarbonylbenzyl benzoate, m-benzylbenzyl benzoate, o-benzoylbenzyl 3-butylbenzoate, 2,4-dichlorobenzyl benzoate, benzyl 1-naphthoate, o-methylbenzyl 2-naphthoate, 2,4-dimethylbenzyl 1-naphthoate, and p-ethoxycarbonylbenzyl 2-naphthoate.
(ii) Examples of the benzyl ester compound in which X is a direct bond or an organic group, and n=2 in the above formula (2) include dibenzyl oxalate, bis(o-methylbenzyl) oxalate, bis(m-ethylbenzyl) oxalate, bis(p-butylbenzyl) oxalate, bis(xcex1-ethylbenzyl) oxalate, bis(2,4-diacetylbenzyl) oxalate, bis(2,4,6-trimethoxybenzyl) oxalate, dibenzyl succinate, bis(o-methoxybenzyl) succinate, bis(m-phenoxybenzyl) succinate, bis(o-methoxycarbonylbenzyl) succinate, bis(p-phenoxycarbonylbenzyl) succinate, bis(m-acetylbenzyl) succinate, dibenzyl adip ate, bis(o-methylbenzyl) adipate, bis(m-ethylbenzyl) adipate, bis(2,4-dimethylbenzyl) adipate, bis(2,4,6-trimethylbenzyl) adipate, bis(p-cyanobenzyl) adipate, benzyl o-methylbenzyl adipate, p-chlorobenzyl p-methylbenzyl adipate, dibenzyl 1,4-cyclohexanedicarboxylate, bis(m-methylbenzyl) 1,3-cyclohexanedicarboxylate, bis(2,4-dimethylbenzyl) 1,4-cyclohexanedicarboxylate, bis(p-phenoxybenzyl) 1,2-cyclohexanedicarboxylate, bis(o-acetylbenzyl) 1,3-cyclohexanedicarboxylate, bis(o-cyanobenzyl) 1,4-cyclohexanedicarboxylate, dibenzyl terephthalate, bis(xcex1-ethylbenzyl) terephthalate, bis(xcex1-butoxybenzyl) terephthalate, bis(p-propylbenzyl) terephthalate, bis(2,6-dimethylbenzyl) terephthalate, bis(m-butoxybenzyl) terephthalate, bis(p-propionyloxybenzyl) terephthalate, bis(o-benzylbenzyl) terephthalate, bis(naphthylbenzyl) terephthalate, bis(p-lactoylbenzyl) terephthalate, bis(2,4-dicyanobenzyl) terephthalate, bis(2,4-difluorobenzyl) terephthalate, bis(xcex1-ethylbenzyl) isophthalate, bis(p-t-butylbenzyl) isophthalate, bis(2,4,6-triethylbenzyl) isophthalate, bis(o-pentyloxybenzyl) isophthalate, bis(m-benzoyloxybenzyl) isophthalate, bis(m-caproylbenzyl) isophthalate, bis(xcex1-ethoxybenzyl) phthalate, bis(m-hexylbenzyl) phthalate, bis(2,4-di-t-butyl-6-methylbenzyl) phthalate, bis(2,4-dimethoxybenzyl) phthalate, bis(m-acetoxybenzyl) phthalate, bis(2,4-dimethoxycarbonylbenzyl) phthalate, bis(m-palmitoylbenzyl) phthalate, dibenzyl 2,6-naphthalenedicarboxylate and dibenzyl 1,4-naphthalenedicarboxylate.
(iii) Examples of the benzyl ester compound in which X is an organic group and n is 3 or more in the above formula (2) include tribenzyl trimellitate, tris(o-methylbenzyl) trimellitate, tris(2,4-dimethylbenzyl) trimellitate, tris(o-ethoxybenzyl) trimellitate, tris(m-acetoxybenzyl) trimellitate, tris(o-methoxycarbonylbenzyl) trimellitate , tris(2,4-diacetylbenzyl) trimellitate, tetrabenzyl pyromellitate, tetrakis(o-ethylbenzyl) pyromellitate, tetrakis(2,6-dimethylbenzyl) pyromellitate, tetrakis(2,4-butoxybenzyl) pyromellitate, tetrabenzyl butane-tetracarboxylate, and tetrakis(p-methylbenzyl) butanetetracarboxylate.
The above-mentioned benzyl ester compounds (A)-2 can be used singly or in combination of two or more kinds.
Among these compounds (A)-2, the following are preferably used in the present invention: benzyl formate, o-methylbenzyl formate, benzyl acetate, 2,4,6-7trimethylbenzyl acetate, benzyl propionate, xcex1-methylbenzyl butyrate, benzyl butyrate, m-methylbenzyl octoate, 2,3-dimethylbenzyl decanoate, benzyl dodecanoate, benzyl hexadecanoate, benzyl cyclohexanecarboxylate, 2,3-dimethylbenzyl cyclohexanecarboxylate, benzyl benzoate, p-acetoxybenzyl benzoate, dibenzyl oxalate, bis(p-butylbenzyl) oxalate, bis(xcex1-ethylbenzyl) oxalate, dibenzyl succinate, bis(o-methoxybenzyl) succinate, bis(m-ethylbenzyl) adipate, bis(2,4,6-trimethylbenzyl) adipate, dibenzyl 1,4-cyclohexanedicarboxylate, bis(2,4-dimethylbenzyl) 1,4-cyclohexanedicarboxylate, dibenzyl terephthalate, bis(xcex1-ethylbenzyl) terephthalate, bis(xcex1-ethylbenzyl) isophthalate, bis(m-hexylbenzyl) phthalate, tribenzyl trimellitate, tetrabenzyl pyromellitate and the like. Benzyl formate, 4-t-butylbenzyl acetate, bis(2,4-dimethylbenzyl) decanoate, dibenzyl terephthalate, bis(2,6-dimethylbenzyl) adipate, bis(2,4-dimethylbenzyl) 1,3-cyclohexanedicarboxylate and the like are preferred in particular.
(A)-3: Benzyl Carbonate Compounds
The benzyl carbonate compound (A)-3 constituting the gamma-ray stabilizer of the present invention is expressed by the following formula (3):
(wherein R9, R10 and R11 are each independently selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 5 to 20 carbon atoms and aryl groups having 6 to 20 carbon atoms; Ar5 and Ar6 are each independently, may have one. or more substituents, aryl groups having 6 to 20 carbon atoms).
In the formula (3), R9, R10 and R11 are each independently selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 20 (preferably 1 to 5) carbon atoms, cycloalkyl groups having 5 to 20 (preferably 5 to 6) carbon atoms and aryl groups having 6 to 20 (preferably 6 to 10) carbon atoms. Here, examples of the alkyl groups include methyl, ethyl and butyl groups; examples of the cycloalkyl groups include cyclopentyl and cyclohexvlgr;ups; and examples of the aryl groups include phenyl group. Especially preferred is the case where R9, R10 and R11 are hydrogen atoms.
Ar5 and Ar6 are each independently, may have one or more substituents, aryl groups having 6 to 20 (preferably 6 to 10) carbon atoms. When said aryl group does not have substituent, examples of Ar5 and Ar6 include phenyl and naphthyl groups. When said aryl group has a substituent on its ring, examples of the substituent include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl and hexyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkoxy groups such as methoxy and ethoxy groups; acyloxy groups such as acetoxy and propionyloxy groups; aralkyl groups such as benzyl group; alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl groups; aryl groups such as phenyl, tolyl and naphthyl groups; acyl groups such as acetyl and benzoyl groups; halogen atoms such as chlorine and bromine atoms; and cyano, nitro, carboxyl and hydroxymethyl groups.
Furthermore, from the view point of gamma-ray stability, the molecular weight of the benzyl carbonate compound expressed by the above formula (3) is preferably not more than 1000; the molecular weight of said compound is especially preferably of from 110 to 500.
Examples of the benzyl carbonate compound preferred in the present invention include dibenzyl carbonate, bis(xcex1-ethylbenzyl) carbonate, bis(2,4-dimethylbenzyl) carbonate, bis(2,4,6-trimethylbenzyl) carbonate, bis(p-butoxybenzyl) carbonate, bis(2,3-dimethoxybenzyl) carbonate, bis(o-phenoxybenzyl) carbonate, bis(p-acetoxybenzyl) carbonate, bis(o-nonyloxycarbonylbenzyl) carbonate, bis(2,4-diphenylbenzyl) carbonate, bis(m-acetylbenzyl) carbonate, and bis(2, 4-difluorobenzyl) carbonate.
Among these benzyl carbonate compounds (A)-3, dibenzyl carbonate,. bis(xcex1-ethylbenzyl) carbonate, bis(2,4-dimethylbenzyl) carbonate, bis(2,4,6-trimethylbenzyl) carbonate and the like are especially preferred in the present invention.
The above-mentioned benzyl carbonate compounds (A)-3 can be used singly or in combination of two or more kinds.
Examples of the benzyl alcohol giving the benzyl ester compound expressed by the above formula (2) or the benzyl carbonate compound expressed by the above formula (3) include the following alcohols:
1) benzyl alcohol and naphthylmethyl alcohol,
2) xcex1-methylbenzyl alcohol, xcex1-butylbenzyl alcohol, xcex1-butoxybenzyl alcohol, xcex1-phenoxybenzyl alcohol, xcex1-cumylbenzyl alcohol and xcex1-phenylbenzyl alcohol,
3) o-methylbenzyl alcohol, m-ethylbenzyl alcohol, p-propylbenzyl alcohol, o-n-butylbenzyl alcohol, p-t-butylbenzyl alcohol, m-hexylbenzyl alcohol, p-octylbenzyl alcohol and o-decylbenzyl alcohol,
4) 2,4-dimethylbenzyl alcohol, 2,6-dimethylbenzyl alcohol, 2,4,6-trimethylbenzyl alcohol, 2,4-di-t-butylbenzyl alcohol and 2,4-di-t-butyl-6-methylbenzyl alcohol,
5) o-methoxybenzyl alcohol, m-ethoxybenzyl alcohol, p-butoxybenzyl alcohol, o-pentyloxybenzyl alcohol, m-decyloxybenzyl alcohol, p-cyclohexyloxybenzyl alcohol, o-phenoxybenzyl alcohol and p-naphthyloxybenzyl alcohol,
6) o-acetoxybenzyl alcohol, m-propionyloxybenzyl alcohol, p-lactoyloxybenzyl alcohol, o-cetyloxybenzyl alcohol and o-benzoyloxybenzyl alcohol,
7) o-benzylbenzyl alcohol, m-benzylbenzyl alcohol and p-benzylbenzyl alcohol,
8) o-methoxycarbonylbenzyl alcohol, m-ethoxycarbonylbenzyl alcohol, p-butoxycarbonylbenzyl alcohol, o-pentyloxycarbonylbenzyl alcohol, m-heptoxycarbonylbenzyl alcohol and p-phenoxycarbonylbenzyl alcohol,
9) o-phenylbenzyl alcohol, m-phenylbenzyl alcohol and p-phenylbenzyl alcohol,
10) o-acetylbenzyl alcohol, m-propionylbenzyl alcohol, p-lactoylbenzyl alcohol, o-caproylbenzyl alcohol, m-lauroylbenzyl alcohol, p-benzoylbenzyl alcohol and m-naphthoylbenzyl alcohol,
11) o-cyanobenzyl alcohol, m-cyanobenzyl alcohol and p-cyanobenzyl alcohol,
12) o-nitrobenzyl alcohol, m-nitrobenzyl alcohol and p-nitrobenzyl alcohol,
13) o-bromobenzyl alcohol, m-bromobenzyl alcohol, p-bromobenzyl alcohol, o-chlorobenzyl alcohol, m-fluorobenzyl alcohol, and so forth.
(B) Phosphorous Ester Derived from Pentaerythritol and Having Spirocyclic Structure
A pentaerythritol phosphorous ester (B) having a spirocyclic structure which constitutes the gamma-ray stabilizer of the present invention together with said benzyl compound (A) has one or more of the unit expressed by the following formula.
Specifically, it is a compound expressed by the following formula (4);
(wherein R12 and R13 are each independently a hydrogen atom, an alkyl group having 1 to 20 (preferably 1 to 10) carbon atoms, a cycloalkyl group having 3 to 20 (preferably 3 to 10) carbon atoms, an aryl group having 6 to 30 (preferably 6 to 20) carbon atoms, an aralkyl group having 6 to 30 (preferably 6 to 20) carbon atoms, an alkylaryl group having 6 to 30 (preferably 6 to 20) carbon atoms or a multivalent phenol residue; the aryl group, aralkyl group, alkylaryl group and multivalent phenol residue may have one or more substituents, each independently).
Use of a specific benzyl compound and a specific phosphorous ester in combination enables not only quality stabilization on molding processing, but also the enhancement of yellowing prevention effect by the specific benzyl compound during gamma-ray irradiation. As the phosphorous ester which suppresses the deterioration of physical properties on the molding of the resin composition and further enhances the gamma-ray resisting effect of the specific benzyl compound, the compounds expressed by the following two formulae are especially preferred among the compounds expressed by the above formula (4).
That is, it is preferable that the phosphorous ester compound is exexpressed by the following formula (4)-1.
(wherein Rxe2x80x2 and Rxe2x80x3 are each independently, may have one or more substituents, tertiary alkyl groups having 4 to 20 carbon atoms). It is further preferable that Rxe2x80x2 and Rxe2x80x3 are each a t-butyl or t-amyl group.
In addition, it is preferable that the phosphorous ester compound is expressed by the following formula (4)-2.
(wherein Ar7 through Ar10 are each independently, may have one or more substituents, aromatic groups having 6 to 30 carbon atoms; W1 and W2 are each independently an alkylidene group, an alkylene group, a cycloalkylidene group, a cycloalkylene group, a phenyl group-substituted alkylidene group, an oxygen atom, a sulfur atom, a sulfoxide group, a cycloalkylidene group, a cycloalkylene group, a phenyl group-substituted alkylidene group, an oxygen atom, a sulfur atom, a sulfoxide group, a sulfonyl group or a direct bond).
Specific examples of said phosphorous ester compounds (B) include the following compounds (No. 1 through No. 39). In the chemical formulae shown below, amyl denotes C5H11xe2x80x94, and Phxe2x80x94 shows a phenyl group. In some of the formulae, each xe2x80x94CH3 of t-butyl group is omitted, and the t-butyl group is represented by X according to the practice in the art, and the representation of a spirocyclic carbon atom is simplified.
In addition, the phosphorous ester may be derived from a phosphorous acid having multiple spirocyclic structures, as shown below.
wherein n1, n2 and n3 are each one of the integers of 2 through 10).
These phosphorous esters may be used singly or in combination of two or ore kinds.
Of said phosphorous esters (B), compounds. of Nos. 2, 3, 6, 13, 15, 16, 19, 23, 24, 26, 26, 30 and 31 are especially preferred in the present invention. Among them, compounds of Nos. 13, 16, 19, 24, 26, 30 and 31 are more preferred.
It is essential in the present invention that at least one kind of said benzyl compound (A) and at least one kind of pentaerythritol phosphorous ester (B) having a spirocyclic structure are combined and used in a specific ratio as constituents of the gamma-ray stabilizer used for thermoplastic resins represented by polycarbonate.
That is, the gamma-ray stabilizer of the present invention contains 0.01 to 10 parts by weight of said phosphorous ester (B) based on 100 parts by weight of said benzyl compound (A).
The use of said benzyl compound (A) and said pentaerythritol phosphorous ester (B) in combination at a specific ratio as the gamma-ray stabilizer obtains a polymer composition wherein the yellowing on the sterilization treatment with gamma-ray irradiation is extremely suppressed, the decay of the properties and the occurrence of defects on molding processing are prevented, and the color tone is not deteriorated even in the case of high temperature holding on molding processing.
Particularly, the combination of a benzyl ether compound of the above formula (1), especially a benzyl ether compound of the above formula (1)-1 as the benzyl compound (A) and a phosphorous ester of the above formula (4), especially a phosphorous ester of the above formula (4)-i or (4)-2 as the phosphorous ester (B) is preferred in the point that the combination not only enables the stabilization of quality of the obtained resin composition on molding processing, but also enables the enhancement of the yellowing preventing effect for resin composition on gamma-ray irradiation as a gamma-ray stabilizer.
If the amount of said phosphorous ester (B) is less than 0.01 part based on 100 parts by weight of said benzyl compound (A), there is almost no effect of blending, that is, a synergistic effect for gamma-ray stabilization cannot be obtained. On the other hand, exceeding of 10 parts by weight of said phosphorous ester (B) is effective for gamma-ray stabilization, but since the phosphorous ester induces the decomposition of the benzyl compound, or lowers the stability of the polycarbonate against heat, water or the like and induces its decomposition, such a large amount of the phosphorous ester disadvantageously causes coloring of thermoplastic resin in a different sense.
In such a gamma-ray stabilizer, said benzyl compound (A) and said phosphorous ester (B), for example, can be separately added to thermoplastic resins such as polycarbonate; however, more preferably they are blended in advance in said ratio, and the blend is added before using, because this makes their synergistic effect exhibit sufficiently and enhances the improving effect on gamma-ray stability.
It has been known so far that various phosphorous esters are used as a coloring preventive agent or antioxidant on molding processing. However, it is completely unknown in the prior art that a combined use of a specific benzyl compound and a specific phosphorous ester as shown in the present invention not only enables quality stabilization on molding processing but also increases yellowing-preventing effect of the specific benzyl compound on gamma-ray irradiation; this finding is unique to the present invention.
The gamma-ray stabilizer of the present invention can be applied widely to all kinds of thermoplastic resins including styrene resins such as polystyrene and AS-resin, polyester resins such as polyethylene terephthalate, polybutylene naphthalate and polyethylene naphthalate, polycarbonate resins, and acrylic resins such as PMMA; however, when applied to polycarbonate among these thermoplastic resins, the effect thereof is exhibited in a remarkable and effective manner. Accordingly, the present invention will be explained using examples in which the gamma-ray stabilizer is applied to polyearbonates.
In the present invention, the polycarbonate is a thermoplastic polymer which consists substantially of a repeating unit represented by the following formula (5)
in the formula (5), R14 and R15 are each independently selected from the group consisting of a hydrogen atom, alkyl groups having 1 to 5 carbon atoms and cycloalkyl groups having 5 to 10 carbon atoms, and R14 and R15 may be bonded with each other; R16 and R17 are each independently a substituent selected from the group consisting of alkyl groups having 1 to 5 carbon atoms, halogen atoms and phenyl group; m and q are each independently 0, 1 or 2.)
Examples of R14 and R15 in the above-mentioned formula include methyl, ethyl, propyl, normal butyl, isobutyl, pentyl and cyclohexyl groups. A cycloalkane ring is formed when R14 and R15 are bonded with each other. Further, examples of R16 and R17 include methyl, ethyl, propyl, normal butyl, isobutyl, pentyl and phenyl groups, chlorine atom and bromine atom.
The polycarbonate represented by the above formula (5) can be a copolymer containing two or more of said repeating units, or can be a blended polymer. Further, some of the repeating units of the polymer may contain ester bonds.
Particularly preferred polycarbonate can be exemplified by the bisphenol A type polycarbonate where both R14 and R15 are methyl groups, and both m and q are 0. The viscosity averaged molecular weight of said polycarbonate is 15,000 to 40,000, or more preferably 20,000 to 35,000.
Typical production methods for such a polycarbonate are commonly an interfacial polymerization method (solution polymerization method) and a melt polymerization method (transesterification method).
In the interfacial polymerization method using phosgene, generally, a divalent phenol is dissolved into an aqueous solution of an acid binder, and the phenol is made to react with the phosgene in the presence of a solvent. An alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is used as the acid binder, while a halogenated hydrocarbon such as methylene chloride or chlorobenzene is used as the solvent.
In the reaction, a end-capping agent is commonly used. The preferred examples of the end-capping agent are monovalent phenols like p-butylphenol and cumylphenol. The amount to be used is 0.01 to 10 mol %, preferably 0.03 to 8 mol % based on one mole of the divalent phenol. The appropriate reaction temperature is 0 to 40xc2x0 C., preferably 20 to 30xc2x0 C., and the appropriate reaction time is in the range about from ten minutes to ten hours. With the progress of the reaction, the pH value of the reaction system is preferably kept at 9 or more. A catalyst may be used to promote the reaction. Examples of the catalyst include tertiary amines such as triethylamine, quaternary ammonium compounds such as tetra-n-butylammonium bromide and quaternary phosphonium compounds such as tetra-n-butylphosphonium bromide.
On the other hand, in the melt polymerization method using a carbonic diester and a divalent phenol, the transesterification is carried out by distilling-off the formed phenol by heating under stirring in the atmosphere of an inert gas, preferably in the presence of a catalyst. The appropriate reaction temperature is usually in the range from 120 to 300xc2x0 C. To promote the distilling-off of the formed phenol, the reaction is carried out in a weak vacuum of 200 to 100 mmHg at a reaction temperature of from 120 to 250xc2x0 C. in the initial stage of the reaction; and in a high vacuum of 10 mmHg or less at a reaction temperature of from 200 to 300xc2x0 C. in the later stage of the reaction. The reaction time is normally from one hour to ten hours; the reaction is continued until the desired degree of polymerization is reached. The following are used as the catalyst for the polymerization: hydroxides of alkali metals and alkaline earth metals, e.g. sodium hydroxide and potassium hydroxide; salts of boron or aluminum hydride; alkoxides; organic phenolates having monovalent, or polyvalent of divalent or higher valent; organic acid salts; carbonate; hydrocarbons; nitrates; nitrites; sulfites; cyanates; thiocyanates; borates; and organic tin, zinc, silicon, germanium, lead, antimony, manganese, titanium and zirconium compounds. Besides these compounds, a common transesterification catalyst or esterification catalyst such as a nitrogen-containing basic compound is used for the polymerization. The catalyst can be used singly, or in combination of two or more kinds. In the case of an alkali metal compound, the amount of the catalyst to be used is normally 10xe2x88x928 to 10xe2x88x925 chemical equivalent based on one mole of the divalent phenol used as the raw material; from the view point of polymer physical properties, preferably 10xe2x88x927 to 5xc3x9710xe2x88x926 chemical equivalent, more preferably 10xe2x88x927 to 2xc3x9710xe2x88x926 chemical equivalent. It is preferred to deactivate the catalyst after the polymerization by a sulfonic acid phosphonium salt, a sulfonic acid ester or the like, which has been disclosed in JP-A 8-59975, because this improves the stability of the polymer.
The gamma-ray stabilizer of the present invention exhibits excellent effects of the present invention by blending 0.01 to 10 parts by weight of a benzyl compound (A) selected from the group consisting of the compounds expressed by said formulae (1), (2) and (3) based on 100 parts by weight of a polycarbonate, and 0.01 to 10 parts by weight of a pentaerythritol phosphorous ester (B) having a spirocyclic structure expressed by said formula (4) based on 100 parts by weight of (A), as described above. It is especially preferable that the total compounding ratio of said gamma-ray stabilizer is 1 to 10 parts by weight based on 100 parts by weight of the polycarbonate.
If the compounding ratio based on the polycarbonate is smaller than said range, there is a small effect on the prevention of yellowing at the time of gamma-ray irradiation and on the prevention of the occurrence of cloudiness and the generation of black foreign matters in molded products. On the other hand, if the compounding ratio is greater than said range, physical properties of the polymer are deteriorated in some cases
The use of a specific benzyl compound (A) and a specific phosphorous ester (B) in the combination at a compounding ratio in said range not only enables quality stabilization on molding processing but also enhances yellowing-preventing effect of the specific benzyl compound on gamma-ray irradiation.
Particularly, the combination of a benzyl ether compound of the above formula (1), especially a benzyl ether compound of the above formula (1)-1 as the benzyl compound (A) and a phosphorous ester of the above formula (4), especially a phosphorous ester of the above formula (4)-1 or (4)-2 as the phosphorous ester (B) is preferred in the point that the combination not only enables the quality stabilization of the obtained resin composition on molding processing, but also enhances the yellowing preventing effect of the specific benzyl compound on gamma-ray irradiation.
For adding the gamma-ray stabilizer, previously known methods can be used. The gamma-ray stabilizer can be added in an arbitrary step of polycarbonate production, or in an arbitrary step of molding processing, i e. before or during molding processing. For example, it can be mixed in the raw material before polycarbonate production or it can be added in an arbitrary step during the polycondensation process of the polycarbonate. Further, it can be added after the completion of polycondensation in a step where, for example, the monomer or oligomer of the polyearbonate, or the solvent used for the production of the polycarbonate is removed, the polycarbonate is not yet converted into chips, and it is in a molten or dissolved state.
For the gamma-ray stabilizer, said (A) and (B) can be added separately to the polymer, but they are preferably blended in advance and added at the same time in order to exhibit the effects of the present invention. It is especially preferred in the sense mentioned above that a gamma-ray stabilizer mixture is prepared by homogeneously mixing both the components, and the mixture is added to the polycarbonate.
Masterbatch technique can be used for adding said gamma-ray stabilizer. In this technique, said gamma-ray stabilizer of high concentration is added to a small amount of a polycarbonate, and the polycarbonate containing the gamma-ray stabilizer of high concentration is blended into a great amount of the polycarbonate containing no gamma-ray stabilizer at a specified ratio, and then the mixture is subjected to extrusion granulation.
The thermoplastic resin composition mixed with the gamma-ray stabilizer of the present invention allows further addition of a desired additive in accordance with a particular objective. For example, one or two or more kinds of the following can be added: a flame retardant such as a halogen compound, a phosphorus compound or a metal salt of sulfonic acid, a flame retardant assistant such as an antimony compound or: a zirconium compound, a drip-proof agent in catching fire such as polytetrafluoroethylene or a silicon compound, all of which can impart flame retardancy to the composition; an impact strength improving agent such as an elastomer; and an antioxidant, a thermal stabilizer, an ultraviolet-ray absorber, an antistatic agent, a plasticizer, a mold-releasing agent, a lubricant, a compatibihlzer and a foaming agent.
The thermoplastic resin composition containing the gamma-ray stabilizer of the present invention can be converted into a desired molded product according to a conventional molding method such as injection molding using a cold runner, injection molding using a hot runner or blow molding. The injection molded product made of the polycarbonate resin composition of the present invention exhibits very little deterioration of color tone while molding processing, and therefore it is possible to get efficiently an injection molded product having good color tone by using the polycarbonate resin composition of the present invention. Particularly, even in the case where the polymer is subjected to injection molding at a high temperature like in the injection molding using a hot liner, an excellently stable molded article free from deterioration attributable to defects such as foaming, the occurrence of turbid spots or the generation of black foreign matters can be obtained.
The present invention provides polycarbonate compositions having excellent gamma-ray stability. Specific examples of the molded articles for medical use, where these resin compositions are preferably applied, include an artificial dialyzer, an artificial lung, an anesthetic inhaler, a vein connector and accessories thereof, a blood centrifugal separation bowl, a surgical instrument, a medical operation device, and a container for intravenous injection solution or the like. Especially, the polycarbonate composition of the present invention is preferably used for a jacket case of an artificial dialyzer. Needles to say, they are useful in further applications.
Gamma-ray irradiation for sterilizing these molded articles for medical use is performed in an atmosphere of air, a deoxygenated gas or the like; however, the use of the gamma-ray stabilizer of the present invention suppresses the yellowing and discoloring of a thermoplastic polymer such as polycarbonate in any atmosphere.
The gamma-ray stabilizer of the present invention does not cause the loss of various original characteristics of a thermoplastic resin when it is mixed to the thermoplastic resin, and further it can provide a thermoplastic resin composition which not only has little yellowing due to gamma-ray irradiation in any irradiation atmosphere, but also can produce molded articles having stable quality and having little defect of the occurrence of turbidness, cloudiness, black foreign matters and the like even in the case where it is molded at a high temperature. Furthermore, the stabilizer is excellent in stability, so that it does not elude from the molded article of said thermoplastic resin even on vapor treatment.
Especially, when mixed to polycarbonate, said stabilizer provides a polycarbonate resin composition having little yellowing due to gamma-ray irradiation without causing the loss of excellent characteristics inherent to the polycarbonate such as transparency, sanitation, dimensional stability, impact strength and thermal resistance. The obtained polycarbonate resin composition, when molded, produces molded products having stable quality and free from the occurrence of defects such as turbidiness, cloudiness, black foreign matters and the like.
Accordingly, the composition containing this gamma-ray stabilizer is stable against sterilization by gamma-ray irradiation, and it is particularly preferred for medical application. The composition containing the gamma-ray stabilizer of the present invention is improved also in the impact on the environment when scrapped. and discarded.

Gamma-ray stabilizer and thermoplastic polymer compound including the said stabilizer


An optical sheet is incorporated in a direct type surface light source device including a light source and is configured to allow light emitted from the light source to exit after changing a travel direction of the light. The optical sheet has a light exiting side lens part including unit lenses juxtaposed to one another and each unit lens is convex toward a light exiting side. A light scattering layer, configured to scatter the light, is provided to each unit lens. The light scattering layer extends along a light exiting side surface of each convex unit lens and constitutes the light exiting side surface of the unit lens. A thickness of the light scattering layer around an apex portion of each unit lens is greater than the thickness of the light scattering layer around each end portion of the unit lens.

As a surface light source device (or back light device) for illuminating a display unit of a transmission type (e.g., a liquid crystal display panel) from its back side, devices of various types have been proposed and put to practical use. The surface light source that has been widely spread is classified into an edge light type and a direct type commonly based on a system of a type for converting a light source which is not the surface light source into the surface light source. For instance, in the surface light source of the direct type, the light source is arranged to be opposed to the transmission display unit. In this case, an appropriate distance is provided between emission members (or emission tubes) of the light source and the transmission display unit. In addition, light diffusing panels, light converging sheets (light collecting sheets) or the like optical sheets are provided in large numbers between the emission members and the transmission display unit.
However, while using so many optical sheets, such a conventional system cannot sufficiently condense the light emitted from the light source toward a front direction (or normal direction relative to the optical sheets). Therefore, the transmission display unit (or LCD panel) has been improved so as not to deteriorate the definition even in the case of the light that comes in an oblique direction.
However, in the case of improving or modifying the transmission display unit, the construction of the LCD panel becomes considerably complicated, leading to a rise in the production cost as well as to deterioration of efficiency of utilizing the light. Especially, in the direct type surface light source device, unevenness of light intensity or luminance (or luminance unevenness) may tend to be seen due to a difference between a portion adjacent to each emission member and a portion not adjacent to the emission member (or difference between a portion immediately above one of the emission member and a portion immediately above a middle point between two emission members positioned next to each other). As a result, in some cases, an image of each emission member (or light image) is likely to be visually confirmed. Such inconvenience can be avoided or dissolved by providing a relatively large distance between the emission members and the LCD panel. However, such a method would lead to another problem that the thickness of the display should be unduly increased. Alternatively, if attempting to suppress such luminance unevenness by increasing an extent of light diffusion and/or by restricting a transmission amount of light, the efficiency of utilizing the light would be substantially deteriorated.
JP2006-259125A discloses a technique for providing a light scattering layer along a surface convex shape of each unit lens in an optical sheet having convex unit lenses provided on a light exiting side of the optical sheet. In the optical sheet disclosed in JP2006-259125A, it is intended to reduce the luminance unevenness by providing the light scattering layer having substantially the same thickness along the surface convex shape of each unit lens. However, in some cases, an effect of reducing the luminance unevenness can not be sufficiently obtained, depending on conditions of the light source and the like, only by employing the technique described in JP2006-259125A.

Optical sheet, surface light source device, and transmission display device


A closure cap for a product container such as a prescription medicine vial, that has a number time and date dials for reminding a user when to take the next dose. The cap's time and date dials are rotatable together or individually with the use of uniquely shaped turning tabs. The dials allow for a user to set the reminder to indicate any hour of the day, any day of the week, and any date of the month. The cap may also have a next and last dose setting. The cap may also have a locking mechanism to prevent inadvertent changes to the set time.

Prescription drugs are a constant growing component to our health care system. Almost half of all Americans take at least one prescription drug. Almost half of all Americans over the age of 65 take three or more prescription drugs. Typically, the effectiveness of the drug or drugs are dependent on the user following the instructions of the prescribing physician, i.e. taking the right amount of the drug at the right time, which is referred to as compliance. However, users frequently forget when to take their next dosage or whether they have taken their last dosage or not, which leads to them either skipping a dosage or repeating a dosage.
Devices to help remind or keep track of a user's drug intake are known. Integrating these devices into the closure caps of the medicine containers that hold the drugs is also known. The integration of the device into the closure cap is advantageous because it prevents the reminder device from being separated from the drugs.
Known integrated devices typically have a limited time duration that they can effectively track or indicate. Specifically, many known devices can only indicate the number of hours or the next day for the next dosage. However, displaying limited time information is problematic when the dosage duration is greater than a day or a week.
Another problem with some known integrated devices is the difficulty users may have in reading and understanding the indicia. The size of the text or reading the text though a small viewing cut-out may make reading the text difficult. Also the layout of the indicia may be confusing making it difficult to understand.
An additional drawback with some of the known integrated devices is the possibility of inadvertently changing the reminder device when the user is trying to remove the closure cap to access the drugs. This is especially likely when the same kind of rotational movement is necessary to either set the reminder device or remove the closure cap from the container.
Cost is another drawback with some of the known integrated devices. Pharmacists are not allowed to reuse medicine containers such as vials or the closure caps for the vials. The caps, even with an integrated time reminder device, are disposed of once the drugs in the vial are used up. Because the caps are a disposable item, the users and drug companies are sensitive to cost associated with them.
In light of the foregoing, it is desirable to provide an inexpensive integrated and disposable time reminder closure cap for a medicine vial that is easy to read and use. It would be advantageous for the time-reminder cap to work with prescriptions having a variety of dosage durations, including durations greater than a day. Furthermore, it would be advantageous if the closure cap had protection against inadvertent changes to the time-date indicators.

Closure cap for a container having time-date indicators


A method according to the invention and a corresponding device (1) designed to cool the exhaust gas (15) of a gas turbine to below its dew point.

Water must be available for the operation of some components in a power plant. By way of example, in a steam electric power plant, a large quantity of water is required for the water-steam circuit in order to generate the necessary quantity of operating and auxiliary steam.
Further, a water reservoir must be replenished continuously during operation as the amount of water in the water-steam circuit decreases due to losses.
The provision or replenishment of water for power plants is, as a rule, easy to achieve in areas where there are adequate water sources or where a well developed supply system has been implemented.
By contrast, in regions ill supplied with water, the provision and maintenance of the amount of water necessary for the operation of the power plant is more problematic.

Method and device for extracting water in a power plant

Abstract: Water (25) accumulating hereby can be used for the power plant operation, so that the provision of (make-up) water for the power plant operation can be dispensed with or at least reduced, especially in areas ill-supplied with water.


A method of rapidly propagating grass and other living plant materials using a sod slurry. The method includes mechanically mixing sod having the desired species of grass or other living plant material with water, fertilizer and a slicking agent to produce a sod slurry which may be sprayed onto a prepared section of land using a conventional pump, hose and nozzle or other types of commercially available spraying equipment. Alternatively, the sod slurry may be poured from a bucket or other suitable container onto the prepared area of land. Mulch and other materials may be added to the mixing tank as appropriate for the selected species of grass or other living plant material. The soil portion of the sod cooperates with other portions of the slurry such as fertilizer or mulch to encourage rapid growth of the selected species of grass or other living plant material on the prepared area of land.

Many grasses and other plants have been successfully propagated using vegetative planting techniques associated with applying live plant material to an appropriately prepared area of land or top soil. Examples of such vegetative techniques include planting grass on prepared land by laying solid slabs of sod on the land, spotting with sod plugs or spraying a water based slurry with grass sprigs (stolons, rhizomes or both) over the prepared land. This last vegetative planting technique may sometimes be referred as hydro-sprigging.
Hydro-sprigging processes typically include harvesting grass sprigs from existing turf with a special digging device or vertical cutting machine. The resulting grass sprigs are generally, but not always completely, free of any soil. The sprigs are typically mixed in a tank with water along with mulch material, fertilizer, wetting agent and/or slicking agent as desired. The equipment associated with hydro-sprigging typically includes a mixing tank having an agitator system such as a paddle with multiple blades attached to a motor for stirring the water based slurry and a pump capable of pumping the resulting slurry of water, grass sprigs, mulch and other material. The mulch material and slicking agent help to prevent clogging of the slurry within the pump and associated tubing and hoses. The mulch material also protects the sprigs once the water based slurry has been sprayed on a prepared area of land.
Examples of equipment and methods associated with propagating grasses and other plants using a sprayable slurry are described in the following U.S. Pat. Nos.:
3,091,436 Method for Producing a Sprayable Fibre Mulch PA0 3,717,285 Apparatus for Spraying a Slurry PA0 4,219,966 Method of Rapid Grass Growth PA0 4,705,217 Material Mixing and Spraying Apparatus PA0 5,012,974 Method and Apparatus for Applying Pregerminated Plantlets PA0 5,361,711 Apparatus for Seeding, Mulching, and Fertilizing Soil
The above listed patents are incorporated by reference for all purposes within this application.

Apparatus and method for propagating grass and other living plants using a sod slurry


A multilayer analytical element for quantitatively assaying ethanol comprising a tetrazolium salt, alcohol dehydrogenase, NAD.sup.+, and an electron transfer agent characterized in that the layer comprising the electron transfer agent also includes a polymer having recurring negatively charged groups and the NAD.sup.+ is in a different layer is disclosed.

Methods for qualitative and quantitative determination of ethanol in aqueous body fluids, particularly human body fluids, are used in medicine and in law enforcement.
In medicine, determination of ethanol in blood is significant in diagnosing liver malfunction and alcoholism. In law enforcement, such assays are used to determine whether an automobile operator is or is not driving under the influence of alcohol.
East German Patent Publication DD 256,196 Al discloses a test strip for determining ethanol content in biological fluids. The test strip is based on the following series of chemical reactions: ##STR1## wherein MTT is [3-(4,5-dimethylthiazolyl-2) 2,5-diphenyltetrazolium].
The test strip contains:
(1) a compound which is suitable for electron transfer such as 1-methoxy-phenazine methosulfate; PA1 (2) a tetrazolium salt, in particular MTT[3 -(4,5-Dimethyl(thiazolyl-2)2,5-diphenyl tetrazolium], and/or INT[2-(4-iodophenyl)- 3-(4-nitrophenyl)-5-diphenyl tetrazolium]; PA1 (3) an alcohol dehydrogenase (ADH); PA1 (4) a nicotinamide adenine dinucleotide (NAD.sup.+); and PA1 (5) a buffer (pH 1-4), in particular a glycine/hydrochloric acid buffer and a buffer (pH of 7-9), in particular semicarbazide buffer. PA1 Poly(acrylamide-co-2-acrylamido-2-methylpropane sulfonic acid, sodium salt). The preferred polymer coverage is 0.6 g/m.sup.2. A useful range is about 0.1 to 4 g/m.sup.2):
The problem is that this element is not suitable for a quantitative assay of ethanol after a 1 to 2 weeks of storage at room temperature. Incorporation of the above chemicals into a dry multilayer element designed for quantitative assays of ethanol consistently underpredicts ethanol concentrations after only three weeks of keeping. In addition, the above prior art element is subject to interference from components of blood serum such as ascorbic acid.


The light from a light source (4) using an LED enters a light entrance surface (2c) of a light guide plate (2) which is integrated with an microprism array sheet (3). A diffusion film (7) for diffusing light is bonded to a top surface (2b) of the light guide plate (2) in a region near the light source (4).

To secure brightness evenness on a display surface of a liquid crystal display apparatus, a backlight built in the liquid crystal display apparatus is strongly required to have brightness evenness for the entire surface of a light emitting surface (active area) that shines a liquid crystal panel. Because of this, in a backlight, conventionally, brightness evenness required for an active area is secured by complicatedly combining a plurality of sheets.
In a method for using several kinds of sheets, because a structure in accordance with use is possible, the degree of freedom of the structure is high; however, because of a large number of sheets and kinds of them, there are problems of complicated designing for securing evenness, much assembly manpower and high cost. To improve these, several methods are proposed as methods that reduce the number of sheets.
For example, a backlight of a reversed-prism type in which uses a prism sheet on one surface of which a prism train is formed with the prism sheet faced with a light-guide plate side is disclosed in a patent document 1 and a patent document 2. Besides, a backlight that has a structure in which a micro-prism array sheet and a light guide plate are unitarily formed with each other is disclosed in a patent document 3 and a patent document 4.    [patent document 1]: JP-A-1994-18879    [patent document 2]: JP-A-2003-302508    [patent document 3]: JP-A-2002-15611    [patent document 4]: JP-A-2002-42528


Computer integrated telecommunication systems are disclosed that provide a message exchange interface that transfers data and control requests generated by applications running on a computer system directly to a telecommunications unit that is adapted to respond to the data and control requests generated by these application programs. In particular, PBX systems are disclosed that include message exchange interfaces that provide fault tolerant operation and that directly map application programs running on a computer system into the controller element of the PBX system. Further systems are disclosed that provide message exchange interfaces that allow the efficient transfer of audio signals between a computer system and a telecommunication unit.

The integration of telecommunication equipment with data processing equipment provides for powerful tools that coordinate the advanced features of digital telephony with the computer processing power of digital computer networks. For example, computer integrated telephony (CIT) systems exist that integrate PBX systems with LAN systems. These PBX CIT systems provide advanced call control and processing. For example, these CIT systems can run applications that detect incoming telephone calls, employ a caller ID function to determine the identified source of the incoming call, pass the source identification information to a computer database application program that employs the source identification as an entry point to the database. From the database, the CIT system can collect relevant customer records such as the invoice statements. The CIT system at that time can transfer both the incoming call and the associated data records to a customer service agent that is most suited for handling this incoming call. For example, if the invoice records show that the account associated with the call is overdue, the CIT system transfers both the incoming call and the relevant invoice data record to an available customer service agent in the billing department of the company.
The CIT systems that exist today include a PBX system that connects to a network server. The PBX system performs the telecommunication functions which include establishing circuit connections between calls from the public telephone system and the individual extension lines within an office. The server performs the data processing applications which can include maintaining databases and running client/server applications. The interface between the PBX and the server establishes a physical and logical connection between the server and the PBX that allows for the operation of CIT systems.
The physical connection between the PBX and the server is typically a conventional computer interface that includes an interface card located in the PBX, an interface card located in the server and a cable connection that extends between these two interface cards. The interface cards typically implement a conventional data communications protocol such as X.25 or ISDN. Through this channel, the PBX and the server can exchange data for coordinating the activities of these two systems during operation of CIT system applications.
The logical connection between the PBX and the server determines how messages are exchanged across the physical interface. Typically, a client/server application running on the computer network generates either requests for actions or requests for instructions for the PBX system. The client passes these requests on to the server. The server has a translator program that translates the message requests from the application program into commands that can be used to operate the PBX. These commands are sent to a software driver that puts the commands into a format suitable for transmission over the data channel, such as the ISDN line or X.25 line. The PBX system receives through its interface card the commands and performs the functions as dictated. The PBX then transmits status messages back to the server system which translates the PBX messages into a format that the application program can understand and the server sends the translated messages to the application program. The application program determines from the translated messages what data records the application program needs to access and proceeds to route the data records to the appropriate client computer and to send further instructions to the PBX system to route any associated incoming calls to the telephone associated with that client's computer.
Although the above systems work to integrate data processing equipment with telecommunications equipment, the integration through the physical and logical connections is often perplexing and difficult to create and maintain. Firstly, most PBX architectures are proprietary, therefore the physical connection between the server and the PBX differs depending on the vendor. For example, an EtherNet port, such as the one found on the NEAX 2000 from Nec America, will be different from the ISDN BRI link employed by AT&T's Definity system. Computer network managers that have to integrate the PBX system into the local area network often find the link between the server and PBX to be both cumbersome and unreliable.
Moreover, these present systems are dependent upon the proper operation of the network LAN server. In the event that the LAN server crashes, the CIT system application that operates the PBX system is brought down. Similarly, any time the computer network manager wishes to reinitialize the network server, those CIT applications that operate the telecommunication systems will also be brought down. Accordingly, the present systems are subject to failure and are difficult to maintain. A further difficulty exists, in that the development of CIT applications is made difficult by the proprietary PBX driver that translates messages from client/server applications into commands suitable for implementation by the PBX system. In particular, as each PBX driver is typically a proprietary software system, the development of standard applications is difficult, if not impossible.
Accordingly, it is an object of the present invention to provide CIT systems that provide an improved interface between telecommunication equipment and data processing systems.
It is a particular object of the present invention to provide a PBX system that more easily integrates with the server of a local area network.
It is a further object of the present invention to provide a LAN--integrated PBX system that has improved fault tolerance.
It is an additional object of the present invention to provide a CIT system that has greater performance and improved reliability.
These and other objects of the present invention shall be made more clear by the following description that references figures having reference numbers wherein like reference numbers refer to the same elements.


A thin-film interference filter structure has a generally wavelength-dependent resonant response to incident optical energy in a predetermined range of wavelengths. The thin-film interference filter structure includes a thermally tunable layer having a thermally tunable optical characteristic such that a range of wavelength-dependent resonant optical responses of the thermally tunable layer are induced by a corresponding range of thermal conditions of the thermally tunable layer. The thin-film interference filter structure is configured to (1) receive a spatially varying pattern of thermal energy at the thermally tunable layer to impart a corresponding spatially varying pattern to the thermally tunable characteristic of the thermally tunable layer, and (2) receive the incident optical energy into the thermally tunable layer and output optical energy having spatial modulation corresponding to the spatially varying pattern of the thermally tunable characteristic.

The present invention is related to the field of solid-state light beam tunable devices, referred to herein as light modulators.
U.S. Pat. No. 7,002,697 B2 discloses an optical instrument which includes a thermo-optically tunable, thin film, free-space interference filter having a tunable passband which functions as a wavelength selector. The filter includes a sequence of alternating layers of amorphous silicon and a dielectric material deposited one on top of the other and forming a Fabry-Perot cavity structure having: a first multi-layer thin film interference structure forming a first mirror; a thin-film spacer layer of amorphous silicon deposited on top of the first multi-layer interference structure; and a second multi-layer thin film interference structure deposited on top of the thin-film spacer layer and forming a second mirror. The filter further includes a lens for coupling an optical beam into the filter; an optical detector for receiving the optical beam after the optical beam has interacted with the interference filter; and circuitry for heating the thermo-optically tunable interference filter to control a location of the passband.
U.S. Pat. No. 7,049,004 B2 discloses a dynamically tunable thin film interference coating including one or more layers with thermo-optically tunable refractive index. Tunable layers within thin film interference coatings enable a new family of thin film active devices for the filtering, control, and modulation of light. Active thin film structures can be used directly or integrated into a variety of photonic subsystems to make tunable lasers, tunable add-drop filters for fiber optic telecommunications, tunable polarizers, tunable dispersion compensation filters, and many other devices.

Method of spatially separating wavelengths of multi-wavelength signal using electronically controlled thermal structure


Methods for manufacturing a flexible bonded magnet, and a high-efficiency small motor using the magnet are disclosed. The flexible bonded magnet is manufactured through the processes of compressing a new compound consisting of flexible thermosetting resin composite and magnetic powder, which contains thermosetting resin, thermoplastic resin, etc.; heat-curing a green sheet derived from the above process; and rolling.

Quite a number of small motors are used in personal computers and the peripheral devices, IT-related appliances and the like apparatus in the field of advanced technologies. These motors are requested to be more compact in the size, higher in the output and efficiency, along with the ongoing pursuit of compactness and lightness in the appliance sector. Among the total production number of small motors, DC motors account for approximately 70%. Most of the general-use DC motors use rubber bonded ferrite magnets. High-performance DC motors employ ring-shaped bonded magnets produced by compressing a composite of magnetically isotropic Nd—Fe—B system magnetic powder and a rigid thermosetting resin such as epoxy resin. Technological developments in the small motors represent the improvements achieved in the field of bonded magnets manufactured by bonding a magnetic powder with a binder.
FIG. 13 describes the technology combinations used for manufacturing conventional bonded magnets. The magnetic powder can be a hard ferrite system magnetic powder, an Alnico system magnetic powder or a rare earth system magnetic powder. The binder can be a flexible resin (e.g. rubber, thermoplastic elastomer), a rigid thermoplastic resin or a rigid thermosetting resin. The forming process can be a calendering, an extrusion, an injection molding or a compression. Conventional combination of these items is indicated with solid lines.
It has been known that the rare earth magnetic powders can be combined with a flexible resin, a rigid thermoplastic resin and a rigid thermosetting resin. It is also known that the rare earth magnetic powders can be combined with a calendering, an extrusion, an injection molding or a compression. Namely, the rare earth magnetic powders are known to be compatible with any one of the items described in the binders and the processes. In the combination of compression process and rare earth system magnetic powder, however, the binder is limited to a rigid thermosetting resin, such as an epoxy resin.
Meanwhile, there are following disclosures in the flexible bonded magnet sector for use in small motors whose output power is lower than several tens of watts, which being subject of the present invention: Japanese Patent No. 2766746 and Japanese Patent No. 2528574 disclose bonded magnets produced by a process of rolling magnetic materials made of rare earth element system magnetic powders and flexible resins. Permanent magnet type motors using the above sheet-formed flexible bonded magnets are also disclosed. However, the maximum energy product (hereinafter referred to as MEP) of these bonded magnets is in the level as low as 50 kJ/m3. Japanese Patent Laid-Open Application No. H5-299221 teaches a method of manufacturing a bonded magnet by rolling a mixture of rare earth-iron-nitrogen system magnetic powder and flexible resin. MEP of this bonded magnet is 42 kJ/m3. Japanese Patent Examined Publication No. H6-87634 discloses a bonded magnet manufactured by compressing a magnetically isotropic R—Fe—B (R signifying at least either one of Nd and Pr) rare earth system magnetic powder and a rigid epoxy resin. A permanent magnet type motor using a multipole-magnetized ring magnet is also disclosed. MEP of which is 77 kJ/m3.
In order to implement a bonded magnet for small motors that is more efficient than the above-described conventional ones, it is essential to have a new binder system and an optimized processing. Specific characteristics needed for the new binder system are that it has a strong adhesive strength and the density of bonded magnet can be raised easily. Insufficient adhesive strength causes partial fracture of magnet body, and the fractured particle would scatter inviting serious damages. If the density is not high enough, the magnetic characteristics do not improve. The present invention aims to solve the above problems, and offer a method for manufacturing a highly-efficient and reliable bonded magnet for use in small motors. A method for manufacturing permanent magnet type motors using the bonded magnet is also disclosed in the present invention.

Manufacturing methods of flexible bonded magnet and motor using the same

Matsushita Electric Industrial Co., Ltd.


An image forming apparatus includes a first substrate, a potential-regulated conductive element, a second substrate having an electrode and an anode electrode connected to the electrode via a resistor, and a spacer which abuts on the conductive element, electrode and anode electrode to regulate a distance between the first and second substrates. The spacer includes a base material. A first resistor film covers a side face of the base material and is electrically connected to the conductive element, electrode and anode electrode. A second resistor film covers a portion of the spacer facing the resistor, and is electrically connected to the electrode and anode electrode. A sheet resistance value of the second resistor film is less than a sheet resistance value of the first resistor film. A resistance value of the second resistor film between the electrode and anode electrode is greater than a resistance value of the resistor.

1. Field of the Invention
The present invention relates to an image display apparatus which has an atmospheric pressure resistant support structure.
2. Description of the Related Art
Among image display apparatuses using electron-emitter devices, a thin flat display apparatus has recently attracted attention as an apparatus to replace a cathode-ray tube display apparatus because of its space-saving and light-weight characteristics.
Such a flat display apparatus includes a hermetic container in which a rear plate having an electron-emitter device and a face plate having an emission member (phosphor) irradiated with an electron beam to emit light, are bonded together via a frame member. The inside of the hermetic container is held in a vacuum of about 10−4 Pa. Image display apparatuses having large surface areas require the use of a mechanism for preventing deformation or destruction of the rear and face plates caused by a pressure difference between the inside of the hermetic container and the outside thereof. Accordingly, the hermetic container in these cases includes a structure support (spacer or rib) made of glass or the like, disposed therein, to support atmospheric pressure. Thus, a distance between the rear plate having a multibeam electron source and the face plate having a phosphor film is normally maintained to be within the range of sub-millimeters or several millimeters, and the inside of the hermetic container is held in a high vacuum as described above. The spacer must not much affect an orbit of electrons flying between the rear and face plates. A cause that affects the electron orbit is a static or dynamic electric field change which results owing to the presence of the spacer by charging near the spacer. Charging of the spacer may be attributed to the emission of secondary electrons from the spacer caused by entry of some electrons emitted from an electron source or electrons reflected on the face plate into the spacer, or the sticking of ions generated as a result of ionization by electron collision.
When the spacer is positively charged, the electrons flying near the spacer are drawn to the spacer, causing a distortion of a displayed image near the spacer. The influence of the charging becomes more conspicuous as the distance between the rear and face plates becomes larger.
Generally, to curb the charging, charges on the spacer are removed by providing conductivity to a surface of the spacer and supplying some currents thereto.
Examples of such display apparatuses are disclosed in Japanese Patent Application Laid-Open Nos. 10-326583 and 2002-237268 (corresponding to European Patents EP 866491 A and EP 1220273 A, respectively). In the JP 10-326583 A, as countermeasures against an undesirable discharge between rear and face plates, a configuration is described in which an anode electrode is divided on the face plate into strips and the strips are connected to a common electrode linked to a high-voltage power supply via a resistor. Also described is a method of electrically connecting the face plate to a spacer.
For the purpose of weakening an electric field of an area (nondisplay area) in which an anode electrode is not formed, JP 2002-237268 discloses a configuration in which an anode electrode and a guard electrode regulated at a potential lower than the anode electrode are disposed on a face plate and in which a resistor film is electrically connected to the anode and guard electrodes. With this configuration, an electric field of an area between the guard electrode and a frame portion is weakened, thereby preventing an occurrence of discharge caused by a shape of a member arranged in the nondisplay area. This display apparatus also includes a spacer which has a resistor film coated on a base material, and the anode and guard electrodes are electrically interconnected.
As described above, in JP 10-326583 A and JP 2002-237268 A, in addition to the anode electrode, various electrodes may be arranged on the face plate on which the anode electrode has been disposed. Such various electrodes can include a common electrode (105) in the case of JP 10-326583 A, and a potential regulated electrode (1015) in the case of JP 2002-237268 A. On the other hand, the spacer disclosed in JP 10-326583 A and 2002-237268 A has an atmospheric pressure resistant structure, and the arrangement of the spacer over the anode electrode and other various electrodes is contemplated so that an atmospheric pressure resistant function can be implemented in various places of a vacuum panel of the display apparatus. As described in JP 10-326583 A and JP 2002-237268 A, in addition to the function as the atmospheric pressure resistant structure, the spacer is required to counter-act charge-up. For this purpose, a charging prevention film on a surface of the spacer is disclosed. However, when the spacer is arranged over the anode electrode and various electrodes as described above, the spacer plays the role of a conductive path which electrically interconnects the anode electrode and various electrodes. Therefore, there is a demand for a better design which not only forms a charging prevention film on a surface of a spacer but also gives consideration to electric behaviors arising between an anode electrode and various electrodes.

Image display apparatus provided with high resistive spacer element


Systems and methods are disclosed that facilitate rapidly warping a two-dimensional image using integer math. A warping table can contain two-dimensional floating point output pixel offset values that are mapped to respective input pixel locations in a captured image. The warping table values can be pre-converted to integer offset values and integer grid values mapped to a sub-pixel grid. During warping, each output pixel can be looked up via its integer offset value, and a one-dimensional table lookup for each pixel can be performed to interpolate pixel data based at least in part on the integer grid value of the pixel. Due to the small size of the lookup tables, lookups can potentially be stored in and retrieved from a CPU cache, which stores most recent instructions to facilitate extremely rapid warping and fast table lookups.

Digital image warping has been evolving for decades, and has grown to embrace a wide variety of applications, such as medical imaging, computer graphics, and computer vision. As computers become more powerful, digital image warping has become well suited to enhance such fields as special effects and image synthesis. Early discoveries related to remote sensors as well as recent developments in computer graphics and digital camera capabilities have contributed greatly to the field of image warping.
Image warping systems have become of interest in the area of computer-generated imaging technologies. For example, some digital warping methods use a technique known as "nearest neighbor" to warp a digital image. However, traditional nearest neighbor warping techniques are limited in precision and in their ability to present a smoothed, warped image to a user, often resulting in unwanted artifacts, or "aliasing," which produces jagged image lines (e.g., "jaggies"). Furthermore, nearest neighbor methods typically require substantial and time-consuming table-lookup protocols, further limiting their efficiency and/or effectiveness.
An unmet need exists in the art for systems and methods that facilitate high-speed, smoother image warping.

Method to quickly warp a 2-D image using only integer math


A floppy disk control circuit enables a floppy disk apparatus to operate at high speed while current consumption is suppressed to no more than 500 mA, i.e. the maximum allowed current of an apparatus using a USB interface. The floppy disk control circuit outputs a reference clock to a spindle motor drive circuit that drives the spindle motor in accordance with the reference clock to rotate a floppy disk. The floppy disk control circuit outputs a slow reference clock for a low rotational speed corresponding to the maximum allowed current at the commencement of the start-up of rotation of the floppy disk and outputs a fast reference clock for a high rotational speed after lapse of a predetermined time from the commencement of the start-up of rotation.

1. Field of the Invention
The present invention relates to a floppy disk control circuit that controls a spindle motor drive circuit that drives a spindle motor to rotate a floppy disk and a floppy disk apparatus having such a floppy disk control circuit.
2. Description of the Related Art
In recent years, floppy disk apparatus that use a USB (Universal Serial Bus) interface instead of the conventional legacy interface as the interface with a host apparatus, such as a personal computer, have become available as commercial products. Such known floppy disk apparatuses are disclosed in for example Laid-open Japanese Patent Application No. H. 11-306501, Laid-open Japanese Patent Application No. 2000-311422 and Laid-open Japanese Patent Application No. 2002-74810. The basic configuration of such known floppy disk apparatuses is as shown in FIG. 4. Specifically, such a floppy disk apparatus 1 includes an interface control circuit 10 that communicates with the host apparatus 2 through a USB, a floppy disk control circuit 11 that receives control data or write data from the interface control circuit 10 or sends read data to the interface control circuit 10 and that controls a spindle motor drive circuit 12, a stepping motor drive circuit 14 and a read/write circuit 16 (described subsequently), a spindle motor drive circuit 12 that is controlled by the floppy disk control circuit 11, a spindle motor 13 that is driven by the spindle motor drive circuit 12 so as to rotate the floppy disk, a stepping motor drive circuit 14 that is controlled by the floppy disk control circuit 11, a stepping motor 15 that shifts a magnetic head 17 (described subsequently), driven by the stepping motor drive circuit 14, a read/write circuit 16 that performs input/output of read and write data with the floppy disk control circuit 11 and performs input/output of electrical signals with respect to a magnetic head 17, and a magnetic head 17 that converts magnetic signals on the floppy disk to electrical signals or converts electrical signals to magnetic signals.
Recently, space-saving and/or cost-reduction are performed by using a semiconductor integrated circuit (hereinbelow referred to as a three-in-one chip) 9 that integrates the three main circuits of the floppy disk control circuit 11, stepping motor drive circuit 14 and read/write circuit 16. This three-in-one chip 9 is a custom product which must be customized for each customer with respect to, for example, the transfer rate of the read/write circuit 16. In contrast, a standard semiconductor integrated circuit is typically used for the spindle motor drive circuit 12.
With commercialization of such USB interface floppy disk apparatuses, it has become possible to increase the read/write speed of floppy disks, which was restricted by the legacy interface.
However, the standard for an apparatus using a USB interface restricts the maximum allowed current to no more than 500 mA. Specifically, if the current value exceeds this, source current may not be supplied from, for example, the host apparatus 2 because the host apparatus 2 regards such an apparatus as unsuitable. In the development of a three-in-one chip for controlling a standard spindle motor drive circuit for application to a floppy disk apparatus capable of reading/writing with double or quadruple speed, the inventor of the present application recognized that this maximum allowed current posed a problem during the start-up of rotation of the floppy disk. More specifically, when the floppy disk of such a double or quadruple speed floppy disk apparatus is rotated at a steady speed, the current consumption is below the maximum allowed current. However, the inventor found that, since the spindle motor requires a large torque during start-up of rotation, as shown in FIG. 5, this current consumption ICC exceeds the maximum allowed current and in fact increases to the vicinity of 1A. The character t0, which has a value of, for example, 500 mS) in FIG. 5 is the time at which read/write operation and other operations of the floppy disk apparatus actually commence.

Floppy disk control circuit and floppy disk apparatus