A composition for preventing creeping for a flux for soldering, which is free from a problem from the viewpoint of the global environment or working environment is provided. The composition comprising a polymer (A) containing the polymer units (a1) derived from an unsaturated ester containing a polyfluroalkyl group and the polymer units (b1) derived from a compound containing a silicon atom and an unsaturated group, and an aqueous medium (B), further optionally including a fluorine type surfactant (c).

The present invention relates to a composition to be used for pretreatment for soldering an electronic part having electric contact points or a printed board having electric contact points, which prevents creeping of a flux for soldering. Further, the present invention relates to a method for soldering by means of such a composition, an electronic part or printed board obtained by such a method, and further an electric appliance.
When various parts are soldered to a printed board, or IC is soldered to an IC socket, it is common to preliminarily treat the printed board with a flux in order to improve the adhesion of the solder. Usually, a flux contains an acidic component and thus is corrosive. Accordingly, it is necessary to prevent adhesion or penetration of a flux at an electric contact portion of an electronic part such as a connector, a switch, a volume or a pre-set resistor or at a portion where no soldering is required in a printed board. Especially in a case of an electronic part, soldering is frequently carried out at a through-hole portion. A phenomenon such that a flux creeps such a through-hole portion by e.g. a capillary phenomenon and penetrates or deposits at an unnecessary portion of the electronic part, is called xe2x80x9ccreeping of a fluxxe2x80x9d, and it is necessary to prevent such a phenomenon.
For the purpose of preventing penetration or deposition of the flux mentioned above, an agent for preventing creeping of a flux is used. As agents for preventing creeping of a flux for soldering, the following examples are known.
(1) A composition containing a compound having a polyfluoroalkyl group or a polymer thereof, and an organic solvent (JP-A-60-49859). Such a organic solvent may be a hydrocarbon type solvent such as heptane, an ester type solvent such as ethyl acetate, a chlorofluorocarbon (CFC) such as 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), or a perfluorocarbon (PFC) having a boiling point of from 60 to 120xc2x0 C., or a fluorine-containing aromatic hydrocarbon type solvent such as 1,3-bis(trifluoromethyl)benzene.
(2) A composition having a low molecular compound containing polyfluoroalkyl groups or a polymer containing polyfluoroalkyl groups, dissolved in an alcohol solvent such as ethanol.
(3) A composition having a fluorine polymer obtained by polymerizing tetrafluoroethylene, a perfluoro(alkylvinyl ether) or vinylidene fluoride, a surfactant and an extender, dispersed in water (JP-A-5-175642).
(4) A composition containing a polymer of an unsaturated ester having a polyfluoro group, a fluorine-containing type surfactant and aqueous medium (JP-A-11-154783).
However, conventional agents for preventing creeping of a flux for soldering, have the following problems.
The composition (1) requires a due care, since the organic solvent is inflammable, and further, it has a problem from the viewpoint of the working environment, since it contains a volatile solvent. Further, when the solvent is a hydrocarbon type solvent, there will be problem that the solubility of the fluorine-containing component in the composition is poor. Further, with respect to CFC among the solvents, its influence over the ozone layer is feared, and its use is restricted by regulations relating to fluorocarbons. HCFC-225 or HCFC-141b, as a substitute for CFC, has similar problems. Further, PFC, a fluorine-containing type solvent, has a high coefficient for warming up the earth, and its influence over the environment is feared. The fluorine-containing aromatic hydrocarbon type solvent is inflammable and has a problem of odor.
The composition (2) is required to have the fluorine content of the low molecular weight compound or the polymer containing polyfluoro alkyl groups lowered in order to increase the solubility of such a compound or a polymer in the alcohol solvent. Further, the effect for preventing creeping of a flux is inadequate.
The fluorine polymer in the composition (3) is non-adhesive and poor in wettability and adhesion to the surface of an electronic part as a substrate. Accordingly, it is practically required to add a spreader. Further, this fluorine polymer has a softening point higher than 150xc2x0 C., and heat treatment at a high temperature of at least the above softening point is required in order to form a film by drying the fluorine polymer particles deposited on a substrate by means of a spreader. The temperature for this heat treatment will be often higher than the heat resistant temperatures of the plastic portions incorporated into electronic parts, and practically, there is a problem that such heat treatment can not be done. On the other hand, if no heat treatment is applied, white fluorine polymer particles are likely to deposit as white solid on electronic parts, and there will be a drawback that the gloss of the treated surface for creeping of a flux is impaired.
In the composition (4), the polymer containing polyfluoro groups is still insufficient in its adhesion, although it is improved as compared with the fluorine polymer particles in the composition (3). Thus the satisfactory adhesion to the surface of an electronic part is not obtained. Further, the hardness of surface of the film obtained from the composition is also insufficient so that the surface tends to be scratched during the working operation, and there will be problem that a flux will be deposited on the scratched parts of the surface.
The present invention has been made to solve the above problems and provides a composition for preventing creeping of a flux for soldering, which comprises a polymer (A) containing the following polymer units (a1), and the following polymer units (b1), and an aqueous medium (B).
Polymer units (a1): Polymer units derived from an unsaturated ester containing a polyfluoroalkyl group, or polymer units derived from an unsaturated ester containing a polyfluoroalkyl group having an etheric oxygen atom inserted in the carbon-carbon bond.
Polymer units (b1): Polymer units derived from a compound containing a silicon atom and an unsaturated group.
The preferred embodiment in the present invention, the polymer unit (a1) is a polymer unit of the compound having the following formula (1).
In the formula (1), Q1, R1 and Rf are defined as follows:
Q1: a single bond or a bivalent connecting group.
R1: a hydrogen atom or a methyl group.
Rf: a polyfluoroalkyl group or a polyfluoroalkyl group having an etheric oxygen atom inserted in the carbon-carbon bond.
The preferred embodiment in the present invention, the polymer unit (b1) is a polymer unit of the compound having the following formula (2).
In the formula (2), R2, R3, R4, and R5 are defined as follows:
R2: a hydrogen atom or a methyl group.
R3, R4 and R5: independently from one another an alkyl group having a carbon number of from 1 to 5, or an alkoxy group having a carbon number of from 1 to 5.
The preferred embodiment in the present invention, the composition is one containing a fluorine type surfactant (C).
The preferred embodiment in the present invention, the softening point of the polymer (A) is at least 40xc2x0 C. and less than 150xc2x0 C.
The preferred embodiment in the present invention, the aqueous medium (B) is a water soluble organic solvent having a boiling point of from 40 to 200xc2x0 C.
The preferred embodiment in the present invention, the surface tension is from 10 to 25 mN/m.
The present invention also provides a method for soldering an electronic part or printed board, which comprises forming a coating film of any one of compositions mentioned above on a part of or the while surface of an electronic part or a printed board, then treating the surface having the coating film thus formed, with a flux for soldering, and then carrying out soldering.
Further, the present invention provides an electronic part or printed board having a property of preventing creeping of a flux for soldering, obtained by forming a coating film of any one of compositions mentioned above on the surface thereof.
Further, the present invention provides an electric appliance employing the electronic part or printed board.
In the present invention, the polymer (A) is a polymer containing the particular constituting units ie, the polymer units (a1) and the polymer units (b1).
In the following, a polyfluoroalkyl group and a polyfluoroalkyl group having an etheric oxygen atom inserted in the carbon-carbon bond, will be generally referred to as a xe2x80x9cRf groupxe2x80x9d. An alkyl group and an alkyl group having an etheric oxygen atom inserted in the carbon-carbon bond, will be generally referred to as an xe2x80x9calkyl group which may contain an etheric oxygen atomxe2x80x9d. An acrylate and a methacrylate will be generally referred to as a (meth)acrylate, and the same applies to other (methacrylic acid, etc.
The polymer units (a1) are polymer units derived from an unsaturated ester containing a Rf group.
The Rf group is meant for a group having at least two hydrogen atoms of an alkyl group which may contain an etheric oxygen atom, substituted by fluorine atoms. The number of fluorine atoms in the Rf group is preferably at least 60%, particularly preferably at least 80%, when it is represented by [(the number of fluorine atoms in the Rf group)/(the number of hydrogen atoms contained in the alkyl group which may contain an etheric oxygen atom, having a structure corresponding to the Rf group)]xc3x97100%.
Further, as the Rf group having an etheric oxygen atom, a Rf group containing an oxypolyfluoroalkylene moiety of e.g. oxypolyfluoroethylene or oxypolyfluoropropylene, may be mentioned.
The carbon number of the Rf group is preferably from 4 to 14, particularly preferably from 6 to 12. The Rf group may be of a straight chain structure or a branched structure, preferably of a straight chain structure. When it is of a branched structure, it is preferred that the branched moiety is present at a terminal portion of the Rf group and is a short chain with from 1 to 3 carbon atoms. Further, the Rf group may have a chlorine atom at the terminal portion. As the structure of the terminal portion of the Rf group, a structure such as CF3CF2xe2x80x94, CF2Hxe2x80x94, CF2Clxe2x80x94 or (CF3)2CFxe2x80x94 may be mentioned.
The Rf group in the present invention is preferably a perfluoroalkyl group (hereinafter referred to as a RF group) which may contain an etheric oxygen atom, having substantially all hydrogen atoms of an alkyl group which may contain an etheric oxygen atom, substituted by fluorine atoms The carbon number of the RF group is preferably from 4 to 14, particularly preferably from 6 to 12. Further, the RF group may be of a straight chain a structure or a branched structure, preferably a group of a straight chain structure.
The RF group is preferably a group having substantially all hydrogen atoms of an alkyl group substituted by fluorine atoms (i.e. a group containing no etheric oxygen atom), particularly preferably a straight chain group represented by F(CF2)nxe2x80x94 [wherein n is an integer of from 6 to 12].
Specific examples of the Rf group include the following structures, but are not limited thereto. Further, in the following specific examples, groups corresponding to structurally isomeric groups, are included.
Examples of the Rf group containing no etheric oxygen atom.
C2F5xe2x80x94, C3F7xe2x80x94 [including both F(CF2)3xe2x80x94 and (CF3)2CFxe2x80x94], C4F9xe2x80x94 [including F(CF2)4xe2x80x94, (CF3)2CFCF2xe2x80x94, (CF3)3Cxe2x80x94 and F(CF2)2CF(CF3)xe2x80x94], C5F11xe2x80x94 [including structurally isomeric groups such as F(CF2)5xe2x80x94, (CF3)2CF(CF2)2xe2x80x94, (CF3)3CCF2xe2x80x94, and F(CF2)2CF(CF3)CF2xe2x80x94], C6F13xe2x80x94 [including structurally isomeric groups such as F(CF2)3C(CF3)2xe2x80x94], C8F17xe2x80x94, C10F21xe2x80x94, C12F25xe2x80x94, C15F31xe2x80x94, HCtF2txe2x80x94 (wherein t is an integer of from 1 to 18), (CF3)2CFCsF2sxe2x80x94 (wherein s is an integer of from 1 to 15). etc.
Examples of the Rf group containing an etheric oxygen atom.
F(CF2)5OCF(CF3)xe2x80x94, F[CF(CF3)CF2O]sCF(CF3)CF2CF2xe2x80x94, F[CF(CF3)CF2O]tCF(CF3)xe2x80x94, F[CF(CF3)CF2O]uCF2CF2xe2x80x94, F(CF2CF2CF2O)vCF2CF2xe2x80x94, F(CF2CF2O)wF2CF2xe2x80x94 (wherein s and t are independently an integer of from 1 to 10, preferably an integer of from 1 to 3, u is an integer of from 2 to 6, v is an integer of from 1 to 11, preferably an integer of from 1 to 4, and w is an integer of from 1 to 11, preferably an integer of from 1 to 6), etc.
The polymer units (a1) in the present invention are preferably polymer units derived from a Rf group-containing (meth)acrylate represented by the following formula (1).
The symbols in the formula (1) have the following meanings.
Q1: A single bond or a bivalent connecting group.
R1: A hydrogen atom or a methyl group.
Rf: Rf group.
Q1 in the group is preferably a bivalent organic connecting group, particularly preferably those mentioned in the following specific examples. Rf in the formula is preferably a polyfluoroalkyl group containing no etheric oxygen atom, particularly preferably a perfluoroalkyl group containing no etheric oxygen atom. The following compounds may be mentioned as specific examples of the Rf group-containing (meth)acrylate represented by the formula (1).
F(CF2)8(CH2)2OCOCHxe2x95x90CH2,
F(CF2)8(CH2)2OCOC(CH3)xe2x95x90CH2,
F(CF2)18(CH2)3OCOCHxe2x95x90CH2,
F(CF2)7CH2OCOCHxe2x95x90CH2,
F(CF2)10(CH2)2OCOC(CH3)xe2x95x90CH2,
H(CF2)8(CH2)2OCOC(CH3)xe2x95x90CH2,
(CF3)2CF(CF2)8(CH2)2OCOC(CH3)xe2x95x90CH2,
F(CF2)8SO2N(CH2CH2CH3)xe2x80x94(CH2)2OCOCHxe2x95x90CH2.
Polymer units (a1) in the polymer (A) may be of one type only, or of two or more types. In the case of two or more types, they are preferably polymer units derived from two or more monomers having different carbon numbers in the Rf group portions.
The polymer units (b1) are polymer units derived from the compound containing a silicon atom and an unsaturated group. The compound containing a silicon atom and an unsaturated group is preferably a compound represented by the following formula (2).
In the formula (2), R2, R3, R4, and R5 have the following meanings:
R2: a hydrogen atom or a methyl group.
R3, R4 and R5: independently an alkyl group having a carbon number of from 1 to 5, preferably from 1 to 3, or an alkoxy group having a carbon number of from 1 to 5, preferably from 1 to 3.
R3, R4 and R5 may be the same group or a different group from one another, and at least one of which is preferably an alkoxy group since the solubility to an aqueous medium is enhanced.
As a specific example of the compound represented by the formula (2) are mentioned the following compounds.
CH2xe2x95x90CHSi(OCH3)3
CH2xe2x95x90CHSi(OC2H5)3
CH2xe2x95x90CHSi(CH3)(OCH3)2
xe2x80x83CH2xe2x95x90CHSi(CH3)(OC2H5)2
CH2xe2x95x90CHSi(OC3H7)3
CH2xe2x95x90C(CH3)Si(OCH3)3
CH2xe2x95x90C(CH)Si(OC2H5)3
The polymer units (b1) in the polymer (A) may be of one type only or of two or more types.
In order that the coating film obtained from the composition containing the polymer (A) has sufficient scratch resistance and stripping resistance, the amount of the polymer units (b1) in the polymer (A) is preferably from 0.1 to 50 wt %, particularly preferably from 1 to 30 wt %.
The polymer (A) may contain polymer units (c1) other than the polymer units (a1) and the polymer units (b2). Such polymer units (c1) is not particularly limited, so long as they are polymer units derived from a monomer (hereinafter referred to as other monomer) containing a polymerizable unsaturated group, no Rf group and no silicon atom. Such other monomer may be employed from known or well known compounds, and one or more of them may be used. It is preferred to employ a polymer (A) containing polymer units (c1) derived from other monomer, since the leveling property will be improved, and the uniformity of the coating film will also be improved.
The polymer units (c1) are preferably selected from polymer units derived from polyolefin type unsaturated esters such as acrylic acid esters, unsaturated esters having epoxy groups, compounds having vinyl groups, and compounds having substituted or unsubstituted amino groups and polymerizable unsaturated groups.
As the polymer units (c1), particularly preferred are polymer units derived from at least one monomer selected from the group of ethylene, vinyl chloride, stylene, (meth)acrylic acid, cyclohexyl(meth)acrylate, an alkyl (meth)acrylate, a mono(meth)acrylate of a polyoxyalkylene diol and glycidyl(meth)acrylate. The polymer units (c1) derived from at least one monomer selected from cyclohexyl(meth)acrylate and an alkyl (meth)acrylate containing the alkyl group having more than 6 (?) carbon numbers are exceptionally preferred, since the leveling property of the composition of the present invention will be improved.
As a specific polymer (A) containing the polymer units (a1) and the polymer units (b1) in the present invention, is preferred a polymer (A) which contains polymer units (a1) derived from Rfxe2x80x94OCOCHxe2x95x90CH2 (Rf is as defined above) and polymer units (b1) derived from CH2xe2x95x90CHSi(OR6)3 (R6 is an alkyl group having a carbon number of 1 to 3).
Further, as a specific polymer (A) optionally including polymer units (c1), is preferred a polymer (A) which contains polymer units (a1) derived from Rfxe2x80x94OCOCHxe2x95x90CH2, polymer units (b2) derived from CH2xe2x95x90CHSi(OR6)3 and polymer units (c1) derived from cyclohexyl (meth)acrylate, since the leveling property, the uniformity of the film, etc will be extremely excellent.
The fluorine content in the polymer (A) is preferably at least 30 wt %, particularly preferably at least 45 wt %, most preferably from 45 to 80 wt %. If the fluorine content is less than 30 wt %, the critical surface tension of the surface of the coating film formed after the treatment tends to be high, whereby no adequate performance for preventing creeping of a flux, tends to be obtained.
The weight-average molecular weight of the polymer (A) is preferably from 1xc3x97103 to 1xc3x97107, particularly preferably from 1xc3x97104 to 1xc3x97105, most preferably from 2xc3x97104 to 5xc3x97104. Further, when the polymer (A) is a polymer containing at least two types of polymerizable units, the arrangement of the respective polymer units may be block or random, particularly preferably random.
The composition of the present invention contains and an aqueous medium (B) together with the polymer (A). The polymer (A) in the composition is preferably dispersed in the form of particles in the after-described aqueous medium. The particle size of particles dispersed in the composition is preferably from 0.01 to 1 xcexcm. The concentration of the polymer (A) in the composition of the present invention is preferably from 0.01 to 3 wt %, particularly preferably from 0.03 to 1 wt %. If the concentration of the polymer (A) is less than 0.01 wt %, no adequate effect for preventing creeping of a flux tends to be obtained, and if the concentration is higher than 3 wt %, the coating film of the polymer (A) to be formed at the time of treatment, tends to be so thick that the solder is likely to be hardly attached.
The composition of the present invention contains the above polymer (A) as an essential component When the composition is to be treated by a usual flux-treating method, the composition is applied to the surface of an electronic part and then dried to soften the polymer (A) to form a uniform coating film.
For the composition of the present invention to be widely used, the softening point of the polymer (A) is preferably low. The heat resistant temperatures of plastics to be used for electronic parts, are about 150xc2x0 C. in most cases, and the softening point of the polymer (A) is accordingly preferably lower than 150xc2x0 C. Further, taking also the drying efficiency into consideration, the softening point of the polymer (A) is preferably at least 40xc2x0 C. and less than 150xc2x0 C., particularly preferably from 80 to 120xc2x0 C.
In the present invention, the surface tension of the composition can be adjusted to from 10 to 25 mN/m (20 to 30xc2x0 C.) by incorporating the above polymer (A) and the fluorine type surfactant (C) in combination to the composition. Usual surface tension of an aqueous dispersion of the polymer (A) containing no fluorine type surfactant (C), is at a level of from 40 to 70 mN/m (20 to 30xc2x0 C.). On the other hand, the critical surface tension of a substrate to which the composition of the present invention can be applied, usually becomes at a level of from 25 to 40 mN/m. Accordingly, the surface tension of the composition of the present invention containing the fluorine type surfactant (C) becomes lower than the surface tension of the substrate, and thus, it is excellent in wettability or adhesion to the substrate and exhibits a performance for preventing creeping of a flux.
As the fluorine type surfactant (C), an ionic surfactant having fluorine atoms, or a nonionic surfactant having fluorine atoms, may be mentioned.
Further, the fluorine type surfactant (C) may be any one of an anionic fluorine type surfactant having Rf groups and anionic groups in combination, a cationic fluorine type surfactant having Rf groups and cationic groups in combination, an amphoteric surfactant having Rf groups and cationic and anionic groups in combination, and a nonionic surfactant having Rf groups and hydrophilic groups in combination.
As tradenames of fluorine type cationic surfactants, xe2x80x9cSurflon S-121xe2x80x9d, manufactured by Seimi Chemical Company Ltd., xe2x80x9cFluorade FC-134xe2x80x9d, manufactured by 3M Co. and xe2x80x9cMegafac F-150xe2x80x9d, manufactured by Dainippon Ink and Chemicals Inc., may be mentioned.
As tradenames of fluorine type anionic surfactants, xe2x80x9cSurflon S-111xe2x80x9d, manufactured by Seimi Chemical Company Ltd., xe2x80x9cFluorade FC-143xe2x80x9d, manufactured by 3M Co. and xe2x80x9cMegafac F-120xe2x80x9d, manufactured by Dainippon Ink and Chemicals Inc., may be mentioned.
As tradenames of fluorine type amphoteric surfactants, xe2x80x9cSurflon S-132xe2x80x9d, manufactured by Seimi Chemical Company Ltd., xe2x80x9cFluorade FX-172xe2x80x9d, manufactured by 3M Co. and xe2x80x9cMegafac F-120xe2x80x9d, manufactured by Dainippon Ink and Chemicals Inc., may be mentioned.
As tradenames of fluorine type nonionic surfactants, xe2x80x9cSurflon S-145xe2x80x9d, manufactured by Seimi Chemical Company Ltd, xe2x80x9cFluorade FC-170xe2x80x9d, manufactured by 3M Co. and xe2x80x9cMegafac F-141xe2x80x9d, manufactured by Dainippon Ink and Chemicals Inc., may be mentioned.
Further, a polymer having a Rf group which is capable of lowering surface tension may be used as a fluorine type surfactant, and xe2x80x9cSurflon S-381xe2x80x9d, manufactured by Seimi Chemical Company Ltd. is mentioned as an example. Such polymer tends to act as a kind of a binder, whereby the strength of the coating film will be improved.
The amount of the fluorine type surfactant (C) is preferably from 20 to 2,000 ppm, particularly preferably from 100 to 1,000 ppm, in the composition. If the amount of the fluorine type surfactant (C) is made at least 20 ppm, the wettability of the composition to a substrate and the performance for preventing creeping of a flux, can be improved. On the other hand, by adjusting it to at most 2,000 ppm, the critical surface tension of the formed coating film tends to be low, and an adequate performance for preventing creeping of a flux can be obtained.
When the fluorine type surfactant (C) is used in a large amount, the fluorine type surfactant (C) tends to remain on the surface of the coating film, whereby the critical surface tension tends to be high, and the desired performance may not be obtained. In such a case, the treated substrate may be rinsed with water to remove the surfactant on the coating film surface. However, two additional steps of rinsing and redrying will then be required, such being undesirable.
Further, the composition of the present invention contains an aqueous medium (B). As the aqueous medium (B), water, or one having a water-soluble organic solvent incorporated to water, may be mentioned. As the water-soluble organic solvent, a ketone, an ester, a glycol, a glycol ether or an alcohol may, for example, be mentioned. When the aqueous medium (B) contains a water-soluble organic solvent, the proportion of water in the aqueous medium (B) is preferably from 50 to 95 wt %, while the proportion of the water-soluble organic solvent is preferably from 5 to 50 wt %.
Further, the water-soluble organic solvent is preferably one having a boiling point of from 40 to 200xc2x0 C., from the viewpoint of drying efficiency. Further, the water-soluble organic solvent is preferably an organic solvent which has a solubility in water at 20xc2x0 C. of at least 1 wt %. Further, the amount of the water-soluble organic solvent in the composition is preferably from 5 to 50 wt %, particularly preferably from 10 to 30 wt %.
The method for preparing the polymer (A) of the present invention is not particularly limited. When it is synthesized by an emulsion polymerization method, the composition of the present invention may directly be obtained, such being preferred. When the emulsion polymerization is carried out, it is preferably carried out by the following method 1 or 2.
Method 1: A method which comprises emulsifying a monomer in the presence of a medium and an emulsifier, followed by polymerization with stirring.
Method 2: A method which comprises emulsifying a monomer in the presence of a medium and an emulsifier by a homomixer or high pressure emulsifying apparatus, prior to addition of a polymerization initiator, and then reacting a polymerization initiating source for polymerization.
In either one of the above methods, when a monomer of gas state such as vinyl chloride is employed as the monomer, it may be continuously supplied under pressure by means of a pressure container. The polymerization initiating source is not particularly limited, and a usual polymerization initiator such as an organic peroxide, an azo compound or a persulfate, or ionizing radiation rays such as xcex3-rays, may, for example, be employed. As the medium, the same as the aqueous medium (B) may preferably be employed.
Namely, when the composition of the present invention is prepared by an emulsion polymerization method, it is preferred to employ a method wherein the compound represented by the formula (1) and other monomers, as the case requires, are emulsion-polymerized in the presence of an emulsifier in an aqueous medium (B).
Further, in all of the above-mentioned methods, the emulsifier may be the fluorine type surfactant (C) or the non-fluorine type surfactant. It is preferred to employ the non-fluorine type surfactant (B2), since it is excellent in the emulsifying activity.
The composition of the present invention preferably contains the non-fluorine type surfactant. Accordingly, it is preferred to prepare it by adding the fluorine type surfactant (C) without removing the non-fluorine type surfactant after the emulsion polymerization.
As the non-fluorine type surfactant, a non-fluorine type non-ionic surfactant having a HLB value of at least 7, a non-fluorine type cationic surfactant having an alkyl group of at least 6 carbon atoms in its molecule, or a non-fluorine type anionic surfactant having an alkyl group having at least 6 carbon atoms in its molecule, is preferred.
As the non-fluorine type non-ionic surfactant having a HLB value of at least 7, a known nonionic surfactant having at least 5 oxyalkylene units in its molecule, is preferred. As the oxyalkylene units, oxyethylene or oxypropylene is preferred. Further, as the non-fluorine type cationic surfactant having an alkyl group of at least 6 carbon atoms in its molecule, an alkyl ammonium salt may, for example, be mentioned, and as the non-fluorine type anionic surfactant having an alkyl group of at least 6 carbon atoms in its molecule, an alkyl sulfate may, for example, be mentioned.
Now, specific examples of the non-fluorine type surfactant in the present invention will be given below.
Polyoxyethylene lauryl ether (HLB=14.5, oxyethylene addition mols=9), polyoxyethylene polyoxypropylene cetyl ether (HLB=9.5, oxyethylene addition mols=l, oxypropylene addition mols=8), polyoxyethyleneoctylphenyl ether (HLB=11.5, oxyethylene addition mols=10), polyoxyoxyethylenenonylphenyl ether (HLB=8.0, oxyethylene addition mols=5), stearyl trimethylammonium chloride, dioctyldimethylammonium chloride, lauryl ammonium sulfate, polyoxyethylenelauryl ether sodium sulfate, dimethyloctyldecylamine acetate.
Among these, preferred as the non-fluorine type surfactant (B2), is, for example, polyoxyethylenelauryl ether, polyoxyethyleneoctylphenyl ether, polyoxyethylenenonylphenyl ether, or dimethyloctyldecylamine acetate.
Further, when a surfactant is used during the emulsion polymerization, either of the fluorine type surfactant (C) or the non-fluorine type surfactant may be used, or at least two surfactants having different ionic natures may be used in combination. However, when surfactants having different ionic natures, are used, it is preferred to combine cationic and non-cationic surfactants, anionic and nonanionic surfactants, or nonionic and amphoteric surfactants.
The composition of the present invention preferably C) contains the non-fluorine type surfactant together with the fluorine type surfactant (C), and the amount of the non-fluorine type surfactant is preferably from 50 to 80 wt %, based on the total amount of the fluorine-type surfactant (C) and the non-fluorine type surfactant. The non-fluorine type surfactant may be the one used in the emulsion polymerization or may be added after the polymerization.
Further, the polymer (A) may be obtained by a solution-polymerization using a fluorine-containing solvent. As the fluorine-containing solvent, HFC such as 1,3-bis(trifluoromethyl)benzene or 2,3-dihydrodecafluoro-(n-)pentane, or HCFC such as C3HF5Cl2 (xe2x80x9cAK-225xe2x80x9d, tradename, manufactured by Asahi Glass Company Ltd.), may be mentioned. It is preferred that such a fluorine-containing solvent is removed after the polymerization, and the polymer (A) is dispersed in the aqueous medium (B) in the presence of the fluorine type surfactant (C) to obtain the composition of the present invention.
The composition of the present invention is diluted to an optional concentration depending upon the purpose and the application, and then coated to a substrate. As the coating method, a common method for coating may be employed. For example, a method such as dip coating, spray coating or coating by an aerosol can having the composition of the present invention packed therein, may be mentioned.
As the substrate, an electronic part having an electric contact, such as a connector, a switch, a volume or a pre-set resistor, or a printed board having an electric contact, may be mentioned. As the portion treated by the composition of the present invention, a portion may be mentioned where creeping of a flux is likely to take place during soldering of an electronic part such as a connector to a printed board. More specifically, a basal portion of an electronic part such as a connector, to be attached to a printed board, a board surface on the side of the printed board on which the electronic part is Lo be mounted, or a through-hole provided in a printed board to attach an electronic part, may, for example, be mentioned.
By the coating with the composition of the present invention, it is possible to prevent deposition of a flux for soldering at an unnecessary portion.
Further, the composition of the present invention provides a merit such that even when deposited at the contact portion, it does not impair the electric characteristics (such as electrical conductivity, etc.) or the outer appearance of the part. Accordingly, it may be applied over the entire surface of the electronic part or the printed board, and a treating method other than as described above, may be employed. For example, a treating method by total dipping or semi dipping with good treating efficiency, may be employed and preferred.
When the composition of the present invention is applied by total dipping, there is the optimum concentration of the polymer (A) for every type of the electronic part as the substrate. Each optimum concentration is shown in Table 1.
The reason why the optimum concentration for every type of the parts is present is as follows. Namely, when the composition is applied by total dipping, the composition will deposit not only at the desired portion (such as only the lead wire portion) but also at other portions, to form a coating film. On the other hand, with the electronic part to be a substrate, the contact load of the electric contact required for electrical conduction is different depending upon the type or the shape. Such difference in the contact load brings about the difference in spalling strength of the coating film. Accordingly, by adjusting the concentration of the composition of the present invention to the contact load, the thickness of the coating film can be modified.
Further, in the semi dipping method wherein only an electronic part which requires the coating film, is dipped in the composition of the present invention, the optimum concentration range of the polymer (A) for the electronic part is preferably at most 3 wt % in the composition, particularly preferably from 0.01 to 0.3 wt %, with respect to any electronic part.
The composition of the present invention is coated to a part of or whole surface of an electronic part or a printed board to be soldered, followed by drying to form a coating film on the surface. After the coating, it is dried and preferably further subjected to curing. By the curing, it is possible to form a more uniform coating film on the surface of the substrate. The curing temperature is preferably a temperature exceeding the softening point of the polymer (A).
The composition of the present invention may contain other additives within a range not to adversely affect the dispersion stability of the polymer (A), the effect for preventing creeping of a flux, the insulating property for the outer appearance. As such other additives, a pH controlling agent to prevent corrosion, a rust-preventing agent, a dye for sensing the concentration of the polymer in liquid, a stabilizer for the dye, a flame retardant, and an antistatic agent, may, for example, be mentioned.
The composition of the present invention serves to form a coating film on the surface of an electronic part or a printed board and to prevent creeping of a flux for soldering. And, an electronic part or a printed substrate, having corrosion by a flux prevented, will be presented.
The electronic part or the printed board, having a coating film formed on the surface by drying the composition of the present invention, will then be treated with a flux for soldering, followed by soldering, whereby a soldered electronic part or printed board will be presented. And, such an electronic part or printed board will be used for various electric appliances. Such electric appliances will be electric appliances with excellent quality, having a trouble to be caused by corrosion by a flux prevented.
Specific examples of such electric appliances include equipments for computers, televisions, audio equipments (radio cassettes, compact discs, mini discs), portable telephones, etc.
The mechanism for the excellent performance of the composition of the present invention is not clearly understood, but is assumed to be as follows. Namely, the softening point of the polymer (A) in the composition is properly adjusted, whereby the coating film will conform to plastic portions of the electronic parts etc. This will improve the adhesion of the film to the above portions and the stripping resistance. Further, during the drying of the composition, the R1 groups in the polymer (A) will align regularly on the film surface to enhance the elimination of the flux efficiently.

Composition for preventing creeping of a flux for soldering and use thereof


The present disclosure relates to a method performed in a radio device 4 connected to a communication network 1 comprising a core network (CN) and a Radio Access Network (RAN), where there is a communication bearer between the radio device and the CN via the RAN comprising a radio bearer between the radio device and a RAN node of the RAN, for adapting a Quality of Service (QoS) of the communication bearer. The method comprises, to the CN, sending a request for a first QoS to be associated with the communication bearer. The method also comprises exchanging data over the radio bearer in accordance with the first QoS of the communication bearer. The method also comprises, to the RAN, sending an indication that a second QoS, lower than the first QoS, should be used for the radio bearer. The method also comprises exchanging data over the radio bearer in accordance with the second QoS.

Mission-Critical MTC Devices
Mission-critical Machine Type Communication (MTC), C-MTC, devices used for communication in e.g. manufacturing, process industry, automotive or medical applications call for higher reliability and lower latency than previously supported in legacy systems (communication standards (generations, G) of the Third Generation Partnership Project (3GPP) 2G, 3G, 4G up to standard Release (Rel) 12) in order to maintain robust control loop functions. Message delays over the wireless link as well as the roundtrip time (RTT) must be kept low. Typical requirements are maximum message delay of no more than 20 milliseconds (ms) and only 0.001 parts per million (ppm) of messages violating this latency requirement. In order to meet such requirements in 4G, e.g. Long Term Evolution (LTE), strict requirements are put on the physical layer not to introduce transport block errors since each retransmission add 8 ms to the message delay. Moreover, interruption of the wireless link must be minimized.
Quality of Service
A standardized QoS concept is applied in 4G and has been designed to allow a service application (app) on a radio device such as a User Equipment (UE) to request end-to-end quality of service. Requirements to be fulfilled by the QoS mechanism are described in (3GPP Technical Specification (TS) 23.207 Version (V) 12.0.0 clause 4.1). It is explicitly stated that the QoS mechanism shall avoid unnecessary processing or complexity both in the UE and in the network nodes, and that unnecessary signalling traffic arising from QoS negotiations shall be avoided.
Each Evolved Packet System (EPS) bearer is associated with a QoS class indicator (QCI) which determines which scheduling policy, queue management policy, rate shaping policy, Radio Link Control (RLC) configuration etc. shall apply for data packets transported between the UE and the serving gateway (SGW) over that bearer (3GPP TS 23.401 V12.7.0 clause 4.7.2). In case of different applications having different QCIs those are mapped to different EPS bearers. Two types of bearers exist, those with guaranteed minimum bitrate (GBR type), and those without such guaranteed bitrate (non-GBR type).
User plane (data) bearers are activated, modified and deactivated by the UE or by the Packet Data Network, PDN, gateway (PGW). On UE side it is handled by the non-access stratum (NAS) which connects the UE to the Mobility Management Entity (MME) that relays the request to the SGW, which in turn relays the request to the PGW (see FIG. 1 for the network architecture of LTE). FIG. 1 shows an LTE architecture with a Radio Access Network (RAN) comprising a plurality of evolved Node B (eNB) base stations each serving one or several cells, with a UE connected to one of the eNB over a radio interface. Each eNB is connected to an SGW for user plane signalling and to an MME for control plane signalling over interfaces named in the figure. The RAN is connected to a PDN such as the Internet via a PGW. The UE specifies the required QoS when activating an EPS bearer, and may also request a modification of an existing bearer—for instance requesting change of the guaranteed bitrate or the QCI by sending a QoS information element with one or more modified parameter values (3GPP TS 24.301 V12.7.0 clause 6.5.4). The PGW responds by rejecting the request, modifying an existing bearer to the desired QoS, or activating a new bearer with the desired QoS to replace the bearer the UE requested to modify.
Standardized QoS levels are shown a table in 3GPP TS 23.203 V12.7.0 clause 6.1.7 for various QCIs. Priority levels are such that the lower the number the higher the priority. The packet delay budget covers end-to-end latency, including radio link(s) and other parts of the network infrastructure. The packet error loss rate is however only for the radio link since no packet loss is expected in the core network (CN) except for losses or latencies due to congestion. The actual packet delay shall in general be lower than indicated in the table for each of the QCIs, particularly for the GBR type of resources, provided that the UE experiences a sufficiently good radio link quality.
In case the eNB cannot sustain the bitrate guaranteed for a bearer it has no other option than to deactivate the concerned bearer since there is no mechanism for re-negotiating QoS between the eNB and the PGW (3GPP TS 23.401 V12.7.0 clause 4.7.2).
FIG. 2 illustrates the nomenclature of different bearers in LTE. Between the in UE and a peer entity (e.g. a service provider, SP) there is an end-to-end connection which comprises an EPS bearer between the UE and the PGW and an external bearer. The EPS bearer comprises an evolved radio access bearer (E-EAB) between the UE and the SGW, and an S5/S8 bearer. The E-RAB in its turn comprises a radio bearer between the UE and the eNB, and an S1 bearer over the S1 interface.


Description and specifications of a new and distinct grapevine cultivar which originated from a hand-pollinated cross of Moored (non-patented)×NY 45791 (non-patented, non-released breeding genotype). This new grapevine cultivar can be distinguished by its seedless, pink berries of distinct V. labrusca-like flavor, small compact clusters, distinctly lobed leaves, medium vigor, and healthy plant.

The new and distinct cultivar of grape named 'A-1710' is described herein. The new cultivar originated from a hand-pollinated cross of Moored and NY 45791 made in 1976. The seedlings fruited in the summer of 1979 in a vineyard near Clarksville, Ark. and one was selected for its seedless, pink berries with good flavor. The fruit grows in compact clusters, the vines have medium vigor and the plants are healthy.

The Board of Trustees of the University of Arkansas


The invention is directed to a safety device for a machine that includes a first transceiver unit for emitting a first light beam in a first time slot and for receiving a second light beam. The safety device includes a second transceiver unit arranged for emitting the second light beam in a second time slot that is different from the first one. The safety device also includes an evaluation unit for determining a reflecting object between the first transceiver unit and the second transceiver unit, only if the first light beam is received by the first transceiver unit in the first time slot or the second light beam is received by the second transceiver unit in the second time slot. Additionally, a non-reflecting object may be detected, if by neither of the two transceiver units in both time slots one of the two light beams is received.

The invention relates to a safety device for a machine. Preferably, the safety device is configured as a non-contact protection device. Further, the invention relates to a corresponding method for safely operating a machine.
Despite increasing automation still machines and plants are employed which require manual operation. In the case of machines, such as for example rolling mills, crushing plants, presses with manual feed, circular saws, shredder machines or cutting tools, generally there is a considerable potential danger for an operator. Due to the required operation of the machine by the operator the requirement exists to equip the machine or plant with protection elements and/or safety mechanisms.
The invention is based on the finding that hitherto safety concepts for machines either provide insufficient protection for the operator or frequently lead to undesired unnecessary false shutdowns since already in the case of harmless deviations of the underlying safety concept an emergency shutdown is performed. An insufficient protection may for instance occur due to the fact that hands or parts of the body of an operator cannot be differentiated from machine elements or workpieces to be processed. This is for instance the case with classic light barriers or light curtains.
Such light curtains are triggered by interruptions of the light signal or the reflecting light signal. If an object enters a response area of the light curtain, the safety function is triggered. A further principle is the triggering by a reflecting element (bracelet, glove, or reflecting workpiece), which allows for a recognizing of exclusively reflecting parts. In this connection it is disadvantageous that a triggering or an interruption is effected exclusively by the reflecting object. Common light curtains responding to the interruption effected by a reflecting element cannot recognize non-reflecting components. A permanent self-monitoring of the light curtain is not possible.
Whilst by the conventional light curtain an intrusion of the object can be detected, however, thereby it cannot be determined whether this intrusion is safety-critical or even desired. Frequently, in such cases due to the high safety requirements in case of doubt an emergency shutdown of the machine in question is initiated. If, in retrospect, the performed shutdown proves to be a false trigger, this may lead to considerable disruptions and/or even product damages. It is true that a certain level of safety could be reached, however, only at a clearly raised risk of triggering unnecessary false shutdowns involving the described disadvantages. A necessary reaching through of tools or components cannot be realized without loss of safety.
Frequently, hazardous spots in machines such as for instance feed portions are protected as far as possible by mechanical covers. In portions that are not covered, often emergency stop elements such as for instance switches, brackets, cable control triggers, or knee switch mats are positioned in reaching or operation proximity. However, so far a reliable or even absolute protection is not provided by these elements, either.

Safety device for a machine and method of operating a safety device


Systems and methods are described for forming a decision tree by considering multiple possible alternative tests or thresholds as well as the possible alternative branches from each test or threshold. This method of making decision trees may be referred to as “look-ahead” or “chart-ahead” recursive partitioning because tests or thresholds can be selected not only for their own ability to divide items into different classes, but also for the ability of future tests or thresholds, enabled by the present tests or thresholds, to further divide items into classes. In preferred embodiments, the method of making the decision tree includes generating clusters of items having similar descriptors and properties, and then evaluating various tests or thresholds for their ability to isolate clusters. Also disclosed are methods of using such decision trees, particularly for the purpose of predicting the unknown properties of molecules.

1. Field of the Invention
This invention relates to methods and systems of predicting properties of molecules.
2. Description of the Related Art
A physical item's unknown conditions can often be predicted based on the item's known conditions. Disease diagnosis is one simple example. If a patient has symptom A, and has symptom B, but does not have symptom C, then it may be predicted that the patient has some particular disease. In this example, the physical item's (the patient's) three known conditions (have symptom A, have symptom B, not have symptom C) are used to predict an unknown condition (that the patient has some particular disease). The conditions that are known or easy to measure or calculate are often called descriptors or X variables. The conditions that are unknown or difficult to measure or calculate, and that are believed to be related to the descriptors, are often called properties, attributes, or Y variables.
Decision trees are a common method of forming predictions about a property of an item, based on descriptors of the item. The structure of a decision tree can be derived by studying existing items. Each of the existing items have known descriptor values and a known property value. The existing items that are used to formulate the decision tree are called training items. The items that have an unknown property and are not used in formulating the decision tree are called new items. The known descriptor values of the training items, in conjunction with the known property values of the training items, are used to develop a connected series of decision points in the form of the decision tree. The decision tree can then be used to predict the unknown property of a new item. For example, based on the descriptors (e.g., age and blood pressure) and the property (whether patient suffered a heart attack) of the training items (medical history data of prior patients), a decision tree can be formulated and then used to predict whether a new patient with given descriptors is likely to suffer a heart attack.
Decision trees classify training items by repeated classification of the training items into classes at nodes of the tree. Classification at each node is based on a test on one or more descriptors (e.g., whether the patient is more than fifty years old, whether blood pressure is greater than 100). Each terminal node (i.e., leaf) of the tree corresponds to a classification of the property. The property of a new item is then predicted by running the new item from the root of the tree through the tests of the decision tree, based on the descriptors of the new item, until a leaf is reached. The property corresponding to the leaf is the predicted property of the new data. In addition to predicting a new property, the decision tree can also aid a user in interpreting relationships between descriptors and the property. For a more detailed description of decision tree methods, please refer to pp. 18-36 of the text of "Classification and Regression Trees", Breiman, Friedman, Olshen and Stone, Chapman & Hall/CRC 1984 (CART hereinafter). For a description of some of the advantages of a tree-structured approach, please refer to pp. 55-58, CART. The disclosure of the above-described book "Classification and Regression Trees" is hereby incorporated by reference in its entirety.
Decision trees may include both classification trees and regression trees. A classification tree's terminal nodes each represent a class of properties. A regression tree's terminal nodes each represent a value of a property. As those ordinarily skilled in the art will appreciate, the disclosed methods and systems can be applied to both classification trees and regression trees. Therefore, the terms such as "class", "classify" and "classification," can be used in the present application to refer to assigning a class to a classification tree terminal node as well as assigning a value to a regression tree terminal node. The term "decision tree" as used in the application refers to both classification trees and regression trees.
Decision trees and various methods for their construction are further disclosed in U.S. Pat. No. 7,016,887, issued on Mar. 21, 2006, hereby expressly incorporated by reference in its entirety.
There exists an unmet need in the art for a method of quickly generating improved decision trees which have higher accuracy in predicting the properties of various molecules while simultaneously having a smaller number of leaves. Smaller trees tend to be more predictive on molecules outside the training set, and are also easier to interpret.

Chart-ahead method for decision tree construction


A gate-driver-on-array (GOA) circuit includes N GOA units cascaded in series to generate N sets of driving signals. Each n-th GOA unit includes a first terminal configured to receive a high-level voltage, a second terminal configured to receive a low-level voltage, and a clock signal terminal configured to receive a clock signal, an input terminal and a reset terminal respectively configured to receive internal signals from two alternative GOA units in the series, a first output terminal configured to output a gate-driving signal, and a second output terminal configured to output a node voltage signal. Each n-th set of the N sets of driving signals includes a first driving signal being a gate-driving signal from a (n−1)th GOA unit, a second driving signal being a gate-driving signal from a n-th GOA unit, and a third driving signal being a node voltage signal from the n-th GOA unit for driving an AMOLED pixel circuit.

The active matrix organic light emitting diode (AMOLED) display apparatuses have many advantages over thin-film transistor liquid crystal display (TFT-LCD) apparatuses due to attributes such as wide viewing angles, highly saturated colors, fast response, high contrast ratio, and an ultrathin panel. Organic light emitting diode (OLED) display apparatuses are current driven apparatuses. An active matrix of thin film transistors (TFTs), usually formed in a Gate Driver on Array (GOA) circuit, is designed to provide a programmable current source at each pixel. A GOA circuit includes N GOA units cascaded in series for generating N gate-driving signals outputted to N gate lines for controlling N rows of TFTs that control the current flowing through the corresponding light emitting diode of each pixel in each row.

Gate driver on array circuit, pixel circuit of an AMOLED display panel, AMOLED display panel, and method of driving pixel circuit of AMOLED display panel

Hefei Xinsheng Optoelectronics Technology Co., Ltd.


A fan track liner assembly for a ducted fan engine which provides for ease of installation and replacement. The assembly includes a plurality of panels; and a plurality of fastening members which are arranged to secure the panels to the fan case of the engine, wherein: each fastening member has a base portion and an elongate arm member, and further wherein: the base portion has an attachment portion which is used to secure the fastening member to the fan case; and the arm member extends from the base portion, and each panel has slotted edge portions on opposing edges at one end of the panel which are each arranged to engage with respective arm members of fastening members on either side of the panel when the panel is assembled with the fastening members by sliding the panel onto the fastening members or vice-versa.

Turbofan gas turbine engines for powering aircraft generally comprise inter alia a core engine, which drives a fan. The fan comprises a number of radially extending fan blades mounted on a fan rotor which is enclosed by a generally cylindrical fan casing.
To satisfy regulatory requirements, such engines are required to demonstrate that if part or all of a fan blade were to become detached from the remainder of the fan, that the detached parts are suitably captured within the engine containment system.
It is known to provide the fan casing with a fan track liner which together incorporate a containment system, designed to contain any released blades or associated debris. FIG. 1 shows a partial cross-section of such a casing and fan track liner.
In the event of a "fan blade off" (FBO) event, the detached fan blade 18 travels radially outward and forwards. In doing so, it penetrates the attrition liner 110. It may also penetrate the septum 112 and aluminium honeycomb layer 114 before engaging the hook 118. The fan track liner must therefore be relatively weak in order that any released blade or fragment thereof can pass through it essentially unimpeded and subsequently be trapped by the fan casing.
In addition to providing blade containment system, the fan track liner includes an annular layer of abradable material which surrounds the fan blades. During operation of the engine, the fan blades rotate freely within the fan track liner. At their maximum extension of movement and/or creep, or during an extreme event, the blades may cut a path into this abradable layer creating a seal against the fan casing and minimising air leakage around the blade tips.
The fan track liner must also be resistant to ice impact loads. A rearward portion of the fan track liner is conventionally provided with an annular ice impact panel. This is typically a glass-reinforced plastic (GRP) moulding which may also be wrapped with GRP to increase its impact strength, or simply higher density honeycomb and tougher attrition material defining an ice impact zone. Ice which forms on the fan blades is acted on by both centrifugal and airflow forces, which respectively cause it to move outwards and rearwards before being shed from the blades.
The geometry of a conventional fan blade is such that the ice is shed from the trailing edge of the blade, strikes the ice impact panel and is deflected without damaging the panel.
Swept fan blades are increasingly used in turbofan engines as they offer significant advantages in efficiency over conventional fan blades. Swept fan blades have a greater chord length at their central portion than conventional fan blades. This greater chordal length means that ice that forms on a swept fan blade follows the same rearward and outward path as on a conventional fan blade but may reach the radially outer tip of the blade before it reaches the trailing edge. It will therefore be shed from the blade tip and may strike the fan track liner forward of the ice impact panel within the blade off zone.
The liner used with a swept fan blade is therefore required to be strong enough to resist ice impact whilst allowing a detached fan blade to penetrate and be contained therewithin.
In recent years there has been a trend towards the use of lighter fan blades, which are typically either of hollow metal or of composite construction. These lighter blades have a similar impact energy per unit area as an ice sheet, which makes it more difficult to devise a casing arrangement that will resist the passage of ice and yet not interfere with the trajectory of a released fan blade.
An Aluminium-Kevlar soft wall casing system is currently the preferred solution for corporate applications based upon cost and weight. This includes a fan track liner within the posting chamber that is exposed to the fan blade—allowing tighter tip clearance and rotor out of balance (OOB) orbit with a fused structure post fan blade off (FBO) similar to existing hard wall casings.
Given the presence of a liner system on a soft wall casing it is believed that the fundamental issue of swept blade penetration of a robust liner (ice impact worthy), exacerbated by part speed part fragment, post FBO is as discussed above. With a fan blisc typical of this engine sector the aerofoil projectile is even less able to penetrate.
If the aerofoil buckles and the tip breaks off before penetration or the released fragment is smaller or the released fragment occurs at part speed, it is possible, based upon test experience, that the fragment will eject forwards through the intake. The certification authorities now expect evidence that this threat has been addressed by the design.
Even if the blade is robust enough to penetrate the liner and allow the soft wall system to function as intended (a blade retained by the Kevlar band), the part speed part fragment threat remains. Therefore, there is a need for a design that allows these fragments to post into the chamber provided and be retained there even if otherwise the casing acts as a hard wall system.


Polyglycerol compositions comprise no more than about 5% by weight of monoglycerol based on non-water ingredients of the polyglycerol composition, and have a combined tetraglycerol and higher polyglycerol content of at least about 55%. Methods of making such compositions from a crude glycerin comprising from 0.01 to 5 wt % of glycerol-containing compounds comprising acetate ester moieties are described.

Glycerol, which is also called glycerin, is a simple polyol compound that is useful as a sweetener, a humectant, as a cosolvent, and as a starting material for manufacture of a number of products, including polyglycerol polymers. USP Glycerin is monomeric glycerol that satisfies United States Pharmacopeia (USP) requirements. USP Glycerin is readily commercially available.
Polyglycerols are prepared by reacting monoglycerol (also known as "glycerin") under conditions to cause condensation of two or more glycerol molecules. See, for example, U.S. Pat. No. 6,620,904. This reaction produces a glycerol composition comprising a distribution of glycerol based compounds containing various numbers of glycerol units.


Provided is a technology of suppressing, in forming an initial ball by using an easily oxidizable conductive wire and pressing the initial ball onto a pad to form a press-bonded ball, an initial ball from having a shape defect, thereby reducing damage to the pad. To achieve this, a ball formation unit is equipped with a gas outlet portion for discharging an antioxidant gas and a discharging path through this gas outlet portion is placed in a direction different from a direction of introducing the antioxidant gas into a ball formation portion. Such a structure widens a region for discharging the antioxidant gas, making it possible to prevent a gas flow supplied from the side of one side surface of the ball formation portion from being reflected by the other side surface facing with the one side surface and thereby forming a turbulent flow.

The present invention relates to a manufacturing technology of a semiconductor device, in particular, to a technology effective when applied to a step of forming an initial ball at the end portion of a conductive wire extending from the tip portion of a capillary and bonding this initial ball to a pad on a semiconductor chip.
Japanese Patent Laid-Open No. 2009-105114 (Patent Document 1) describes a technology of providing a plurality of gas jet nozzles around a capillary and forming an initial ball at the tip portion of the capillary while jetting an inert gas from these gas jet nozzles.
Japanese Patent Laid-Open No. Sho 60-244034 (Patent Document 2) describes a technology of placing the tip portion of a capillary at a penetration member provided in a cylindrical cover and forming an initial ball at the tip portion of this capillary while feeding an internal space of the penetration member with an inert gas from a gas suction hole associated with this penetration member.
Japanese Patent Laid-Open No. 2008-130825 (Patent Document 3) describes a technology of placing a tip portion of a capillary in a through-hole provided in a porous member and forming an initial ball at the tip portion of the capillary while feeding an inert gas from the porous member.    [Patent Document 1] Japanese Patent Laid-Open No. 2009-105114    [Patent Document 2] Japanese Patent Laid-Open No. Sho 60-244034    [Patent Document 3] Japanese Patent Laid-Open No. 2008-130825

Method of manufacturing semiconductor device


A bearing lubricating housing (100) comprising a lubricating housing body (110). The bearing housing (100) is designed to retain a rolling element bearing assembly (200) while providing axial motion when the housing (100) is assembled within an interior of a guiding tube (310). The bearing housing (100) includes a series of channels (118) and/or passageways (114, 116) forming a lubrication matrix for collecting a lubricant from an interior surface (312) of the guiding tube (310) to the rolling element bearing assembly (200).

1. Field of the Invention
The present invention relates to a self lubricating bearing configuration. More specifically, the self lubricating bearing assembly integrates a lubrication system into a bearing carrier, wherein the bearing carrier collects a lubricant from a surface of a guiding tube during an axial motion and transfers the collected lubricant to the bearing.
2. Discussion of the Related Art
Bearings integrate an outer ring, an inner ring, and a plurality of rolling elements assembled therebetween. The assembly enables ration of one ring respective to the other ring. The outer ring is inserted into an interior of a first element and a second element is inserted into an interior diameter of the inner ring. This configuration enables controlled rotation of the first element and second element respective to one another.
Bearings are employed in a wide variety of applications. The applications can vary from an occasional use to continuous commercial operations. Bearings comprise rolling elements that rotate against a bearing raceway of each of the inner ring and the outer ring. The longevity and reliability of the bearings can be enhanced through maintenance, which includes lubrication. Many of the bearing applications have a negative impact on lubrication. Commercial operations are desired to minimize downtime, thus limiting any time available for maintenance; including lubrication. Other applications integrate the bearings into complex assemblies. The complex assemblies are generally difficult and time consuming to dismantle to access and lubricate the bearings.
Centralizer bearings are employed to guide and retain rotating components in a radial direction. The centralizer bearings can also be employed in an axial direction by enabling a sliding motion. Centralizer bearings can be integrated into complex assemblies, making lubrication difficult. The motion of elements within the system and location of the centralizer bearing further aggravates the potential for solutions for lubricating the centralizer bearing. Lubrication may be applied to one portion of the assembly, but is not easily transferred to the opposite part of the assembly to lubricate the centralizer bearing.
Thus, what is desired is a simple, self-lubricating solution for applying a lubricant to a centralizer bearing or any other bearing integrated into a complex machine.
The solution provides several advantages, including reduced downtime for maintenance. The continuous lubrication ensures the bearing remains properly and adequately lubricated during extending periods of operation. The self-lubrication increases the time period for operation, thus increasing equipment uptime. The increased uptime increases productivity and the return on investment of the equipment. The self-lubricating design retains the lubricant within the machine, resulting in a cleaner maintained machine. Grease and other lubricants that could accumulate on exterior surfaces of the equipment attract and retain dirt and other contaminants. The dirt and other contaminants can creep into areas between moving parts increasing friction and wear. The contaminants can prematurely degrade the elements of the equipment causing premature failure.

Self lubricating robust centralizer bearing design and method of use


Systems and algorithm for providing a service to a client includes defining a virtual infrastructure in which a plurality of virtual machines are running on a virtualization layer with at least one of the virtual machine executing an image processor algorithm. The image processor algorithm is configured to access framebuffer data of a specific virtual machine that includes the service to be controlled, process the framebuffer data to generate image data packets with contextual information by scanning the framebuffer data to discern the image of the virtual machine display, obtaining connection parameters and client characteristics of a connection to the client, analyzing the framebuffer data to balance performance of the connection and performance of the specific virtual machine, and selecting a compression technique for processing the framebuffer data to generate image data packets. The image data packets are transmitted to the client for presenting on a display device.

1. Field of the Invention
The present invention relates to methods and systems for accessing, controlling, and interfacing with a virtualized computer service over short and long distances with a lightweight client.
2. Description of the Related Art
In a virtual environment, a virtual resource is remotely accessed and controlled through a combination of hardware and software protocols. The virtual environment includes a plurality of dynamically scalable virtual resources that are provided as services over the Internet and are aptly termed cloud services due to the "clouding" of the underlying technology for accessing such virtual resources. A typical virtual environment can be characterized as a collection of computing hardware, a hypervisor that sits on top of the computing hardware and provides access to the computing hardware and a plurality of guests (Virtual machines or VMs) that sit on top of the hypervisor accessing the hardware through the hypervisor. A plurality of clients are used to connect to and remotely control the virtualized computer services (or simply virtual services) within the virtual environment via protocols. These protocols/derivations of protocols are used in the compression/decompression of the direct graphics stream associated with the VMs, using redundancy elimination and graphic instruction rewrites so as to enable lower bandwidth communication than the original graphics stream.
The above protocols have their own limitations and challenges. A significant limitation is that these protocols are tied to a specific platform or platforms (graphics/operating system layer) requiring the operating system or the graphics chip to be in harmony with the compression/decompression protocol. This means that the compression protocols leverage the "context" of the operating system graphics so that the commands can be interpreted and executed at the remote VMs within the virtual environment. The adverse effects of such platform specific protocols include usage of large CPUs both in the thin client and at the virtual service side for compression/decompression and interpretation of the progressive imagery and difficulty in handling large latency of long distance WAN network connections. Additional disadvantages include requirement of specialized chips (graphics chips) to decode the compression in certain circumstances, and high network consumption in other circumstances.
Additionally, the basis for formulating such platform specific software-based protocols was to drive fast performance through the operating system graphics layer. As a result, the direct interpretation of the operating system graphics commands was critical to the design of such protocol, making their design platform-specific, which carried over into the virtual machine environment. Another drawback of customized protocols is that their complexity makes them incompatible with many lightweight client devices, such as low power thin clients or mobile smartphone-class devices.
It is in this context, embodiments of the invention arise.

This patent is subject to a terminal disclaimer.

Systems and algorithm for interfacing with a virtualized computing service over a network using a lightweight client


The present application relates to copper-doped double perovskites, for example, copper-doped double perovskites of the formula (I) and to uses thereof, for example as low-bandgap materials such as a semiconducting material in a device. The present application also relates to methods of tuning the bandgap of a Cs2SbAgZ6 double perovskite (for example, wherein Z is Cl) comprising doping the double perovskite with copper.Cs2Sb1-aAg1-bCu2xZ6  (I)

With an impressive increase in photoconversion efficiency (PCE) within the past decade,1 hybrid organic-inorganic lead halide perovskites have prompted global research due to their potential use in high-efficiency solar cell technologies. However, despite their promising electronic properties and low production costs for photovoltaic and optoelectronic applications,2 commercialization of lead halide perovskites has been hindered, for example, by their instability3 as well as by long-term health and environmental concerns4 for example, related to the leaching of Pb2+ due to their water solubility.5
The general formula for perovskites of recent interest in photovoltaic research is ABX3, where A=Cs+, MA+, or FA+ (wherein MA=methylammonium, FA=formamidinium), B=Pb2+ or Sn2+, and X=Cl−, Br−, or I−. To improve the photovoltaic efficiency and stability of metal halide perovskites, alternative synthetic design approaches have included the incorporation of A-site mixed cations2(d),6 and mixed halides7 as well as isovalent (Sn2+, Co2+, Sr2+)8 or heterovalent (Bi3+, Au3+, In3+)9 B-site cations. These modifications influence the photovoltaic performance and optical properties and can lead to enhanced stability.10 Although MASnI3 may be a less toxic alternative to the isoelectronic Pb2+ sister materials, displaying a bandgap of 1.15 eV,11 it is unstable under ambient conditions due to rapid oxidation to Sn4+ which negatively impacts the photovoltaic properties of the material.12
Research has shown that replacing the B-site cation with a combination of trivalent (B′), and monovalent (B″) cations results in the formation of A2B′B″X6 double perovskites that mimic the ABX3 perovskite structure while displaying desirable air and moisture stability,13 as well as bandgap tunability.14 For example, Cs2BiAgX6 (X=Cl, Br) shows visible light absorption with indirect bandgaps of 2.77 and 1.95 eV for X=Cl and Br, respectively.13(a),13(c) Similar bandgap tunability also has been observed by alloying of Sb3+ and In3+ in Cs2BiAgBr6.14(a) In 2017, Deng et al.15 successfully synthesized Cs2SbAgCl6 double perovskites with an indirect bandgap of 2.6 eV, while Tran et al.14(b) prepared a series of B′-site mixed-cationic Cs2(SbxIn1-x)AgCl6 (0≤x≤1) double perovskites that show an indirect to direct bandgap modification. The structural and photophysical properties of nanocrystals,16 low-dimensional (i.e., 2D) double perovskites,17 hysteresis-free solar cells,18 and highly stable thin films19 of Cs2BiAgBr6 double perovskite have recently been reported. A small bandgap Tl-containing Cs2AgTlBr6 double perovskite has emerged;20 however, the acute toxicity of thallium makes it ill-suited to replace lead. A new class of layered double perovskite, namely, Cs4CuSb2Cl12, displays a reduced bandgap, although at the cost of photovoltaic efficiency due to the restriction in structural dimensionality.21 A less-toxic, low-bandgap (ca. 1-1.4 eV) 3D double perovskite material synthesized from inexpensive and highly abundant elements remains desirable.
Altering the optical and electronic properties for semiconductors is a useful approach in modern device applications.22 For example, homo- and heterovalent metal ion doped lead halide perovskites have been reported to enhance the optical and electronic properties of both nanocrystalline23 and bulk materials.9,12,24 Additionally, for example, Slavney et al.14(c) reduced the bandgap of Cs2BiAgBr6 by successful Tl doping, and Nandha and Nag25 enhanced the visible light emission properties of Cs2InAgCl6 via Mn2+ doping.
The ns2 outer shell electronic configuration of the B-site in the 3D ABX3 (B=Pb2+, Sn2+) perovskite structure is responsible for strong direct bandgap absorption and superior photovoltaic properties. Occupied and unoccupied 6s2 and 6p0 orbitals, respectively, of Pb2+ contribute to form valence band maximum (VBM) and conduction band minimum (CBM), respectively.26 A2B′B″X6 double perovskites allow a large diversity of B′- and B″-sites and hence diverse orbital compositions in its band edges. Because double perovskite materials exhibit dominant metal-to-metal charge transfer (MMCT), their electronic band structure relies heavily on the energies of B′- and B″-site metals' frontier orbitals.20 For example, it has been shown when Pb2+ is replaced with isoelectronic Bi3+ and Tl+ in MA2BiTlBr6, a direct bandgap material is formed, whereas replacing Tl+ with Ag+ yields an indirect bandgap material, Cs2BiAgBr6.13(c),14(c) Similarly, the Cs2SbAgCl6 double perovskite shows an indirect bandgap transition, where the Sb-5s/Ag-4d and Sb-5p orbitals are the main contributors to the VBM and CBM, respectively.14(b)
Vargas et al. have reported a layered 2D double perovskite, Cs4Sb2CuCl2, that exhibits a direct transition with a narrow bandgap (ca. 1 eV) due to the presence of an unpaired electron in Cu2+ (3d9 configuration).21(a) The [CuCl6]4− octahedra are inserted between [SbCl6]3− layers, corner sharing to each [SbCl6]3− neighbor in the extended crystalline structure. These corner-shared octahedra are similar to the 3D perovskite network, which is useful for their major photovoltaic success in lead-halide perovskites.26 The much smaller bandgap of Cs4Sb2CuCl12 is due to favorable orbital overlap of the Cu-3d orbitals with Cl and Sb orbitals, which broadens the VBM and minimizes the bandgap.21(a)

Copper-doped double perovskites and uses thereof

The Governors of the University of Alberta


A cleaning apparatus includes a first cleaning roller, and a second cleaning roller. The first cleaning roller is contrived to contact to a circumferential surface against a moving member to be cleaned and to apply a bias to the member to be cleaned while rotating such that the circumferential surface of the first cleaning roller moves in a same direction as the member to be cleaned moves. The second cleaning roller is contrived to contact to the member to be cleaned after the member has been cleaned by the first cleaning roller and to rotate such that a circumferential surface of the second cleaning roller moves in a direction opposite a direction in which the member being cleaned moves.

1. Technical Field
The present invention relates to a cleaning apparatus and an image forming apparatus contrived to use a liquid developer including a carrier liquid and a toner.
2. Background Technology
Technologies have been disclosed for removing a liquid ring produced when an intermediate transfer belt, a photoreceptor, or other image carrier is cleaned in an image forming apparatus that uses a liquid developer (Patent Document 1 and Patent Document 2).
The image forming apparatus recited in Patent Document 1 is contrived to recover a liquid ring formed on a belt with a removal blade, guide the liquid with a wedge shaped liquid guide member so as to transfer the liquid to a removed liquid conveying roller, and remove the liquid from the surface of the roller with a scraper.
The image forming apparatus recited in Patent Document 2 is contrived to remove a liquid ring formed on a photoreceptor using a wedge shaped blade.    [Patent Document 1]: Japanese Laid-open Patent Application No. 2002-82530    [Patent Document 2]: Japanese Laid-open Patent Application No. 1-206387

Cleaning apparatus and image forming apparatus


A paper sorting system allows the high speed determination of color, glossiness and the presence of printed matter for individual sheets of paper in a stream of waste paper. Sorting criteria may be selected from a plurality of predefined options to sort the paper stream.

1. Field of the Invention
The present invention relates generally to a multi-grade object sorting system and method and more particularly to such a system for sorting various grades and colors of paper.
2. Description of the Prior Art
The high speed sorting of waste paper has only recently become feasible with the introduction of a system by the Assignee of the present invention as described in pending U.S. patent application Ser. No. 09/301,715, filed Apr. 29, 1999, entitled "System and Method for Sensing White Paper", by Bruner et al., the details of which are incorporated herein by reference. The first such system as described in the aforementioned application, could only identify and separate white office paper. The technique utilized for identifying and distinguishing such paper was the presence of the fluorescence of the paper when subjected to ultraviolet light.
It has been proposed to sort paper based on color as described in European Patent Publication No. EP0873797A2, published on Oct. 28, 1998. The European patent publication proposed to utilize visible light, ultraviolet light, x-rays and/or infrared light to illuminate the paper, while observing the reflected light with one or more cameras connected to a central processing unit. The disclosure of the European patent office publication is very vague with regard to the manner in which such a process could be conducted, and its sorting system utilizes mechanical pickers thus indicating that the system would operate at relatively low speeds.
Sorting systems for other objects other than paper are available which utilize red, green and blue light emitting diodes as light sources. An example is a product sold by the Assignee of the present invention is described in pending U.S. patent application Ser. No. 09/183,349 filed Oct. 30, 1998 by Doak, the details of which are incorporated herein by reference.
Thus, it is seen that there is a need for a system capable of sorting paper based upon the color of the paper, and capable of doing so at sufficiently high speeds as to make the process economical. Such a system, along with various refinements thereof is the subject of the present invention.

Multi-grade object sorting system and method


A paint apparatus includes a framework having a beam, a carriage constrained to move reciprocally along the beam, a first robot mounted to the carriage and movable relative to the carriage except in a direction parallel to the beam, and a second robot mounted to the carriage and movable relative to the carriage except in the direction parallel to the beam. The first and second robots and are spaced from each other in the direction parallel to the beam and in a direction perpendicular to the beam. As a result, interference between the first and second robots and is prevented and paint sprayed onto each other is prevented.

1. Field of the Invention
The present invention relates to a paint apparatus for automatically painting a workpiece conveyed into a painting booth by a conveyor using two painting robots which are prevented from interfering with each other.
2. Description of the Prior Art
Painting automobile bumpers is an automated process in which the bumpers are usually painted using painting robots. A painting line is provided with a plurality of painting robots to increase production efficiency.
FIG. 12 illustrates one example of a conventional automobile bumper painting line. A conveyor 2 extends through a painting booth 1 and automobile bumpers 3 are conveyed into the painting booth 1 at regular intervals. The bumpers 3 are stopped at four predetermined painting positions to be painted. Painting robots 4 are arranged adjacent to respective painting positions. The respective painting robots 4 paint the respective, hatched portions of the bumpers 3.
FIG. 13 illustrates another example of a conventional bumper painting line which is shortened as compared with the painting line of FIG. 12. In the painting line of FIG. 13, a conveyor 12 extends through a painting booth 11 where two predetermined painting positions are provided. End portions of a bumper 13 are painted at a first painting position using two first painting robots and the remaining portion of the bumper 13 is painted at a second painting position using two second painting robots. By arranging the two first robots and the two second robots in an opposing relationship with each other, the length of the painting booth 11 is shortened.
However, in this opposing arrangement of the painting robots, the following problems result:
First, because painting programs of the opposing robots are executed independently of each other, there is an overlapping zone in the working areas of the opposing robots. As a result, the opposing robots may collide with each other in the overlapping zone as shown in FIG. 14. To prevent such a collision requires complicated and difficult programming.
Second, the opposing robots spray large amounts of paint onto each other. When the sprayed paint falls from the robots onto a bumper positioned under the robots, the paint quality of the bumper is deteriorated.


An improved decorative button of a pet collar, including a decorative cap, a resilient pad member and a decorative attaching paper. The decorative cap has a projecting rectangular rivet stem and a lower arch surface around the rivet stem corresponding to a curve of the pet collar. The resilient pad member is formed with a central rectangular hole corresponding to the rivet stem of the decorative cap. The rectangular hole of the resilient pad member has four slightly upward bent side edges. Each of four corners of the rectangular hole is formed with a linear fissure and a middle portion of each long side edge of the rectangular hole is also formed with a linear fissure, whereby the rivet stem is irreversibly fitted into the rectangular hole of the resilient pad member. The resilient pad member is resiliently deformed in accordance with the curve of the decorative cap and the pet collar so as to closely associate therewith without producing any clearance or unplane projecting portion.

The present invention relates to an improved decorative button for a pet collar, including a decorative cap, a resilient pad member and a decorative attaching paper. The decorative cap has a projecting rectangular rivet stem. The resilient pad member is formed with a central rectangular hole corresponding to the rivet stem of the decorative cap. The rectangular hole of the resilient pad member has four slightly upwardly bent side edges. Each of four corners of the rectangular hole is formed with a linear fissure and a middle portion of each long side edge of the rectangular hole is also formed with a linear fissure, whereby the rivet stem is irreversibly fitted into the rectangular hole of the resilient pad member. The resilient pad member is resiliently deformed in accordance with the curve of the decorative cap and the pet collar so as to closely associate therewith without producing any clearance or nonplanar projecting portion.
A conventional pet collar has a decorative button as shown in FIG. 1. The decorative button has a downward extending rivet stem. The lower surface of the decorative button around the rivet stem is plane so that when the decorative button is secured on the pet collar, a clearance 10 is formed between the lower surface and a top surface of the pet collar as shown in FIG. 2. The hairs of a pet are liable to be clamped in the clearance and the pet may get hurt thereby.
It is therefore necessary to provide an improved decorative button for a pet collar, which can closely associate therewith so as to avoid a clearance in which the hairs of the pet mat are clamped as well as avoid a nonplanar projection which will abrade the neck of the pet and hurt the same.

No. 34, Alley 4, Lane 37, Sec. 2, Chang Hsin Road

Hsin Chuan Li, Ho Mei Chen, Changhua Hsien


Extendable lever arms can be used to facilitate insertion and removal of a sled into and out of a chassis. Each extendable lever can include a rotatable body, a primary arm, and a secondary arm. The rotatable body can be rotatably coupled to the housing of the sled, and can optionally include latching elements to secure the sled within the chassis, as well as optional removal features to facilitate disengaging the sled from the chassis. The secondary arm can be coupled to the primary arm to move between a retracted position and an extended position. When in the retracted position, the secondary arm can be positioned adjacent to the primary arm to avoid blocking access to ports of the sled. When in the extended position, however, the secondary arm can be positioned to provide a longer lever arm to facilitate insertion and removal of the sled.

Computing devices, such as computer servers, often include one or more sleds that are insertable into receiving spaces in a chassis. Insertion and removal of these sleds often involve securing or un-securing the sled within the chassis, as well as optionally coupling connectors on one side of the sled to connectors already present in the chassis. Insertion and/or removal of a sled into and/or out of a receiving space in a chassis can be especially difficult with larger and/or heavier sleds, or with sleds having connectors with high insertion and/or removal forces. There is a need for a sled that can be easily handled, especially during insertion into and/or removal from a chassis.


The present invention relates to polynucleotides encoding adult plant pathogen resistance proteins. Also provided are transgenic plants expressing these polynucleotides to enhance the resistance of the plants to pathogens.

Numerous genes conferring resistance to pathogens have been identified and used in plant breeding. However, single-gene pathogen resistance in plants often becomes ineffective due to the emergence of new virulent races of the disease agent. In contrast, durable disease resistance in plants is generally thought to be controlled by multiple genes.
The wheat (Triticum aestivum) quantitative trait locus, Lr34, provides durable adult plant resistance to the biotrophic fungi causing the diseases leaf rust, stripe rust, stem rust and powdery mildew (Dyck, 1977 and 1987; German and Kolmer, 1992; Bossolini et al. 2006; Spielmeyer et al. 2008). This is despite the limitation that it is not effective at the seedling stage under normal field conditions. Cultivars with the resistance locus Lr34 such as Frontana have had effective durable resistance to the leaf rust fungus Puccinia triticina Eriks (Dyck et al., 1966; Singh and Rajaram, 1994). To date, isolates of P. triticina with complete virulence to Lr34 have not been detected (Kolmer et al., 2003).
Lr34 resistance has remained genetically inseparable from Yr18 that confers resistance to stripe rust (P. striiformis) (Singh, 1992a; McIntosh, 1992). Co-segregation of Lr34/Yr18 with other traits such as leaf tip necrosis (Ltn1), powdery mildew (recently designated Pm38), tolerance to barley yellow dwarf virus (Bdvl) and spot blotch (Bipolaris sorokiniana) have been documented (Singh, 1992a, b; McIntosh, 1992; Joshi et al., 2004; Spielmeyer et al., 2005; Liang et al., 2006). These multi-pathogen resistance traits have made the Lr34/Yr18 locus one of the most valuable gene regions for disease resistance breeding in wheat.
A few rust resistance genes have been isolated and cloned from wheat (Feuillet et al., 2003; Huang et al., 2003; Cloutier et al., 2007) and other cereals (Collins et al., 1999; Brueggeman et al., 2002) and are predominantly from the nucleotide binding site-leucine rich repeat (NB-LRR) class of major resistance (R) genes. The only known exception is the barley Rpgl rust resistance gene which encodes a protein kinase. These genes encode gene-for-gene resistance against single pathogens and generally lead to hypersensitive responses in the plant tissues upon infection. In contrast, Lr34 confers a broad spectrum resistance against several obligate biotrophic pathogens including fungi from the Ascomycetes and Basidiomycetes. Rubiales and Niks (1995) reported that Lr34 is associated with reduced intercellular hyphal growth but not with a hypersensitive response or papilla formation.
The molecular basis of quantitative non-race-specific, adult plant pathogen resistance-type or partial resistance encoded by genetic systems such as, for example, Lr34 therefore remains unknown.

Grains Research and Development Corporation

Commonwealth Scientific and Industrial Research Organisation