Abstract: A molded piece set including two or more colored molded pieces having different compositions. One of the colored molded pieces and at least another of the colored molded pieces have a CIEDE2000 color difference of 1.0 or lower and a metamerism index of 1.0 or lower. Also disclosed is a computer color matching system, a database including color data sets corresponding to two or more respective colored molded pieces having different compositions and a method for producing the molded piece set.

Abstract: A molded piece set including two or more colored molded pieces having different compositions. One of the colored molded pieces and at least another of the colored molded pieces have a CIEDE2000 color difference of 1.0 or lower and a metamerism index of 1.0 or lower. Also disclosed is a computer color matching system, a database including color data sets corresponding to two or more respective colored molded pieces having different compositions and a method for producing the molded piece set.

Abstract: The invention provides a fluoroelastomer molded article having luster and low odor permeation. The fluoroelastomer molded article contains a fluoroelastomer and has luster.

Abstract: The present invention provides a method for producing a fluoroelastomer using an emulsifier which is inexpensive and hardly remains in product polymers. The present invention is related to a method for producing a fluoroelastomer, wherein vinylidene fluoride and at least one fluoroolefin monomer other than vinylidene fluoride are copolymerized in the manner of an emulsion polymerization in the presence of an emulsifier represented by C5F11COOM, wherein M represents H, NH4 or an alkali metal.

Abstract: The present invention provides a TFE/Pr type elastomer being excellent in not only amine resistance but also heat resistance and chemical resistance and having a small gel content, and a crosslinkable composition comprising the elastomer. The above-mentioned fluorine-containing elastomer is a fluorine-containing elastomer being crosslinkable with the compound (A), comprising 40 to 70% by mole of tetrafluoroethylene unit, 30 to 60% by mole of propylene unit and 0.1 to 2.5% by mole of a carboxyl group-containing vinyl monomer unit and having a Mooney viscosity at 121° C. of 5 to 100.

Abstract: The present invention provides a method of producing a fluoroelastomer excellent in dispersion stability at low cost, at a high rate of polymerization and in high yields. The present invention is a method of producing a fluoroelastomer comprising an emulsion polymerization of a fluorinated monomer in the presence of a water-soluble radical polymerization initiator, wherein the emulsion polymerization is carried out in the presence of a compound (1) containing a functional group reactive in radical polymerization and a hydrophilic group and a fluorinated compound (2) containing a fluorocarbon group comprising 1 to 6 continuously united carbon atom with fluorine atom directly bound to each of them as well as a hydrophilic group.

Abstract: A process for preparing a fluorine-containing polymer which includes a first step for preparing a dispersion of fluorine-containing emulsified particles (A) having ionic functional groups where a fluorine-containing monomer mixture (i) is polymerized by using a water soluble radical polymerization initiator (a) without addition of an emulsifying agent, and a second step for preparing a fluorine-containing polymer (b) having a small amount of ionic functional groups where fluorine-containing monomers (ii) are emulsion-polymerized by using a radical polymerization initiator (b) in the presence of the fluorine-containing emulsified particles (A) having ionic functional groups without addition of an emulsifying agent.

Abstract: A fluoroelastomer mixture, including: a peroxide-vulcanizable fluoroelastomer (A) containing an iodine atom; and a peroxide-vulcanizable fluoroelastomer (B) containing an iodine atom. The fluoroelastomer (A) is a copolymer (a1) consisting of 50 to 85 mol % of a vinylidene fluoride unit and 15 to 50 mol % of a perfluoro(alkyl vinyl ether) unit, or a copolymer (a2) consisting of 45 to 85 mol % of a vinylidene fluoride unit, 1 to 30 mol % of a tetrafluoroethylene unit, and 14 to 30 mol % of a perfluoro(alkyl vinyl ether) unit. Further the fluoroelastomer (B) has a fluorine content of 70.0% or more. Also disclosed is a composition for peroxide vulcanization containing the above fluoroelastomer composition (i), a polyfunctional unsaturated compound (ii) and a peroxide (iii), as well as a method for producing the fluoroelastomer mixture.

Abstract: There is provided a fluorine-containing elastomer composition assuring easy kneading and providing a crosslinked article having improved strength. The fluorine-containing elastomer composition comprises (A) an elastomer of a vinylidene fluoride/hexafluoropropylene copolymer having a branching coefficient of 30 to 300 ppm, a Mooney viscosity (ML1+10: 121° C.) of 7 to 80 and a molecular weight distribution (Mw/Mn) of 1.5 to 4, and (B) an elastomer of a vinylidene fluoride/hexafluoropropylene copolymer having a storage modulus G? at 180° C. at 500 cpm of 500 to 900, and a mass ratio of (A)/(B) is 70/30 to 90/10.

Abstract: The present invention provides a process for preparing a fluorine-containing elastomer in a high productivity comparable to that of non-iodine transfer polymerization process by carrying out an iodine transfer polymerization at high pressure. The present invention also provides a fluorine-containing elastomer prepared by this process, and fluorine-containing molded articles. The process is a batch copolymerization process conducted under conditions that the reduced temperature of the critical constant is at least 0.95 and the reduced pressure of the critical constant is at least 0.

Abstract: The invention provides a fluoropolymer composition capable of improving the characteristics of the cured material obtained therefrom. A fluoropolymer composition comprising a methylene group-containing fluoropolymer (A) and a hydrosilylation catalyst (B), wherein the methylene group-containing fluoropolymer (A) has methylene group-containing repeating units in the main chain thereof and is capable of hydrosilylation in the presence of the hydrosilylation catalyst (B) and one terminus of the chain is a carbon-carbon double bond or an Si—H group and the other terminus of the chain is an Si—H group or a carbon-carbon double bond.

Abstract: This invention provides a novel compound which can be properly used as a surfactant, a method of producing a fluoropolymer, surfactant and a fluoropolymer aqueous dispersions using the novel compound. This invention is a fluoroalkylcarboxylic acid derivative which is represented by the general formula (i): Rf1(OCH2CF2CF2)n1OCX1X2CF2(Rf2)n2COOM??(i) wherein Rf1 represents a straight or branched fluoroalkyl group containing 1 to 20 carbon atoms, which fluoroalkyl group may optionally contain 1 to 5 oxygen atoms in the principal chain thereof, Rf2 represents a straight or branched fluoroalkylene group containing 1 to 25 carbon atoms, said fluoroalkylene group may optionally contain 1 to 5 oxygen atoms in the principal chain thereof, n1 represents an integer of 0 to 3, n2 represents an integer of 0 or 1, X1 and X2 are the same or different and each represents hydrogen atom or fluorine atom, and M represents NH4 or a monovalent metal element.

Abstract: A fluoroelastomer mixture, including: a peroxide-vulcanizable fluoroelastomer (A) containing an iodine atom; and a peroxide-vulcanizable fluoroelastomer (B) containing an iodine atom. The fluoroelastomer (A) is a copolymer (a1) consisting of 50 to 85 mol % of a vinylidene fluoride unit and 15 to 50 mol % of a perfluoro(alkyl vinyl ether) unit, or a copolymer (a2) consisting of 45 to 85 mol % of a vinylidene fluoride unit, 1 to 30 mol % of a tetrafluoroethylene unit, and 14 to 30 mol % of a perfluoro(alkyl vinyl ether) unit. Further the fluoroelastomer (B) has a fluorine content of 70.0% or more. Also disclosed is a composition for peroxide vulcanization containing the above fluoroelastomer composition (i), a polyfunctional unsaturated compound (ii) and a peroxide (iii), as well as a method for producing the fluoroelastomer mixture.

Abstract: The present invention provides a novel fluorine-containing rubber composite material having both of excellent fuel impermeability and excellent cold resistance, a fuel impermeable sealing material comprising the composite material and a process for preparing the composite material. The fluorine-containing rubber composite material comprises crosslinked particles of fluorine-containing silicone rubber dispersed in a fluorine-containing rubber. It is preferable that the fluorine-containing rubber comprises a vinylidene fluoride/tetrafluoroethylene/perfluoro vinyl ether copolymer, and the composite material has cold resistance of not more than ?35° C. and fuel permeability of not more than 500 g·mm/m2·day. The fuel impermeable sealing material comprises the composite material. The process for preparing the composite material comprises a step for co-coagulation of a fluorine-containing rubber emulsion and an emulsion of crosslinked fluorine-containing silicone rubber.

Abstract: A curable composition comprising (A) a vinylidene fluoride elastomer which is a copolymer of vinylidene fluoride (a1), at least one kind of perfluoroolefin (a2) selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoro(alkyl vinyl ether) and a cyano group-containing monomer (a3) (a proportion of the vinylidene fluoride exceeds 20% by mole), (B) a specific curing agent and (C) a compound generating ammonia at 40° to 330° C. The present invention can provide a curable composition of a vinylidene fluoride elastomer assuring improved crosslinking speed, and a molded article obtained from the curable composition. Physical properties under normal conditions are improved by the presence of a solvent having affinity for the compound generating ammonia.

Abstract: A curable composition comprising (A) a vinylidene fluoride type elastomer which is a copolymer of vinylidene fluoride (a1), at least one perfluoroolefin (a2) selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and perfluoro(alkyl vinyl ether) and a cyano group-containing monomer (a3) (the proportion of vinylidene fluoride exceeds 20% by mole), and (B) a compound generating ammonia at 40° to 330° C. alone as a curing agent. The present invention can provide a curable composition of a vinylidene fluoride type elastomer assuring improved crosslinking speed and making it possible to use a cheap curing agent, and a molded article obtained from the curable composition. Physical properties under normal conditions can also be improved by the presence of the solvent having affinity for the compound generating ammonia.

Abstract: The present invention has for its object to provide a fluorocopolymer which is available at low cost, has fluidity at room temperature, and is curable, a method of producing the same copolymer and a curable composition having good processability and in situ moldability. The present invention is directed to a fluorocopolymer which is fluid at room temperature and curable, and which is obtainable from a trifluorovinyl group-containing monomer with an ethylenically unsaturated double bond moiety being a trifluorovinyl group.

Abstract: The present invention provides a fluorine-containing elastomer composition comprising a fluorine-containing elastomer (A) and a fluorine-containing elastomer (B) having a fluorine amount of at least 67% by weigh and a lower molecular weight than the fluorine-containing elastomer (A), wherein the fluorine amount of the fluorine-containing elastomer (B) is larger than a fluorine amount of the fluorine-containing elastomer (A). The present invention also provides a molded article obtained by crosslinking the fluorine-containing elastomer composition.

Abstract: There is provided a fluorine-containing elastomer composition assuring easy kneading and providing a crosslinked article having improved strength. The fluorine-containing elastomer composition comprises (A) an elastomer of a vinylidene fluoride/hexafluoropropylene copolymer having a branching coefficient of 30 to 300 ppm, a Mooney viscosity (ML1+10: 121° C.) of 7 to 80 and a molecular weight distribution (Mw/Mn) of 1.5 to 4, and (B) an elastomer of a vinylidene fluoride/hexafluoropropylene copolymer having a storage modulus G? at 180° C. at 500 cpm of 500 to 900, and a mass ratio of (A)/(B) is 70/30 to 90/10.

Abstract: The present invention provides a TFE/Pr type elastomer being excellent in not only amine resistance but also heat resistance and chemical resistance and having a small gel content, and a crosslinkable composition comprising the elastomer. The above-mentioned fluorine-containing elastomer is a fluorine-containing elastomer being crosslinkable with the compound (A), comprising 40 to 70% by mole of tetrafluoroethylene unit, 30 to 60% by mole of propylene unit and 0.1 to 2.5% by mole of a carboxyl group-containing vinyl monomer unit and having a Mooney viscosity at 121° C. of 5 to 100.