Abstract: To provide a novel and effective cleaning method which can give a cleaned fluorine-containing rubber molded article for semiconductor production apparatuses. The method of cleaning the fluorine-containing rubber molded article for semiconductor production apparatuses, which comprises washing the fluorine-containing rubber molded article at least once with ultra pure water which has a metal content of not more than 1.0 ppm and does not contain fine particles of not less than 0.2 &mgr;m in an amount of more than 300 per 1 ml.

Abstract: To provide a packaging material being capable of maintaining a highly clean state, wherein the number of fine particles having a particle size of not less than 0.2 &mgr;m and being present on its surface facing an article to be packaged is not more than 5,000/cm2, a steam permeation degree at 40° C. at 90% RH is not more than 30 g/cm2·24 hr, a total amount of gas (excluding steam) to be generated when heating at 80° C. for 15 minutes is not more than 5 ppm and a total amount of water to be generated when heating at 80° C. for 30 minutes is not more than 13 ppm.

Abstract: There is provided a method of end-chlorination of a fluorine-containing compound which can easily provide a fluorine-containing monomer having a functional group such as nitrile group at relatively low cost. The method of chlorinating an end of a fluorine-containing compound having iodine atom at an end thereof comprises reacting a fluorine-containing organic compound having iodine atom at a molecular end thereof and represented by the formula (I): RfCX2I  (I) wherein Rf is an organic residue having fluorine atom, X is hydrogen atom or chlorine atom, with a chlorine gas at a temperature of from 150° C. to 180° C. under irradiation with light to cleave the C—I bond and replace iodine atom with chlorine atom.

Abstract: In the emulsion obtained by forcedly emulsifying by applying a high shearing force on the water insoluble liquid in the presence of a small amount of emulsifying agent, at least one of fluorine-containing monomers being in the form of gas at ordinary temperature at atmospheric pressure is emulsion-polymerized stably and efficiently. An amount of the emulsifying agent is an amount which does not change the number of water insoluble liquid particles in the emulsion during the polymerization.

Abstract: To provide the filler which is added to a composition for a sealing member, etc. for sealing of semi-conductor production equipment being apt to be damaged greatly by mixing of a foreign matter and is small in a change in weight in either of the oxygen plasma irradiation and CF4 plasma irradiation, and the crosslinkable elastomer composition. The filler is used for the crosslinkable elastomer and has an imide structure, and a change in weight of the filler is not more than 4 mg/cm2·hr in either of the oxygen plasma irradiation and CF4 plasma irradiation. The crosslinkable elastomer composition comprises the filler and the crosslinkable elastomer such as a fluorine-containing elastomer.

Abstract: According to the present invention, it is possible to provide a molding material, for example, a sealing material for semiconductor-related production apparatuses which comprises a fluorine-containing multi-segment polymer being excellent in mechanical properties (particularly at high temperature), abrasion resistance and transparency and ensuring reduced contamination and reduced gas permeation while maintaining inherent characteristics of a fluorine-containing elastomer such as flexibility, elasticity, sealing property, chemical resistance and heat resistance. A molding material comprising a fluorine-containing multi-segment polymer having an elastomeric fluorine-containing polymer chain segment and a non-elastomeric fluorine-containing polymer chain segment, in which the elastomeric fluorine-containing polymer chain segment imparts flexibility to the whole polymer and has perhaloolefin units as a recurring unit in an amount of not less than 95% by mole.

Abstract: There is provided a fluorine-containing elastomer molded article which is obtained by irradiating the fluorine-containing elastomer molded article with a plasma and has a center line average roughness of not less than 0.65 &mgr;m or a fluorine-containing elastomer molded article which is obtained by applying a resin coating layer on a fluorine-containing elastomer substrate, has a small peeling strength and a small etching rate at the irradiation of plasma and is excellent in detachability and whiteness. There is provided particularly a molded article suitable as various sealing materials for semiconductor production apparatuses.

Abstract: A rubber laminate in which a rubber layer (1) containing the following rubber composition (A) is adhered by vulcanization to a rubber layer (2) containing another rubber composition (B). Rubber composition (A): Composition comprising 100 parts by weight of a mixture and 0.1 to 15 parts by weight of a peroxide crosslinking agent admixed therewith, the mixture comprising 5 to 95 wt. % of a peroxide-crosslinkable fluororubber containing vinylidene fluoride copolymerized therein in a proportion of 45 to 88 mole % and having a number average molecular weight of 20,000 to 200,000, and 95 to 5 wt. % of an acrylic rubber containing 0.1 to 1.5 wt. % of a polyfunctional monomer copolymerized therein and having a functional group rendering the acrylic rubber peroxide-cocrosslinkable with the fluororubber and a functional group effecting the copolymerization of the monomer with an acrylic ester.

Abstract: To provide a solid fluoroelastomer having nitrile group at the end which gives a crosslinked product being excellent in heat resistance, solvent resistance, chemical resistance, compression set and cleanliness, and an economical process for preparation thereof. The process for preparing a nitrile group-containing fluoroelastomer by converting amide group contained in a polymer molecular chain of a solid fluoroelastomer into nitrile group in the presence of a dehydrating agent.

Abstract: A rubber laminate in which a rubber layer (1) containing the following rubber composition (A) is adhered by vulcanization to a rubber layer (2) containing another rubber composition (B).

Abstract: To provide a solid fluoroelastomer having nitrile group at the end which gives a crosslinked product being excellent in heat resistance, solvent resistance, chemical resistance, compression set and cleanliness, and an economical process for preparation thereof. The process for preparing a nitrile group-containing fluoroelastomer by converting amide group contained in a polymer molecular chain of a solid fluoroelastomer into nitrile group in the presence of a dehydrating agent.

Abstract: A process for preparing a fluorine-containing polymer through emulsion polymerization method which enhances productivity while maintaining excellent physical properties of the fluorine-containing polymer and comprises (a) a first polymerization step for emulsion-polymerizing a fluorine-containing monomer or a mixture of a fluorine-containing monomer and a non-fluorine-containing monomer in an aqueous medium in the presence of a radical polymerization initiator and an emulsifying agent, (b) a dilution step for diluting the obtained aqueous emulsion of polymer particles with water to reduce the number of emulsified polymer particles per unit amount of aqueous medium in the emulsion and a concentration of emulsifying agent, and (c) a second polymerization step for emulsion-polymerizing a fluorine-containing monomer and/or a non-fluorine-containing monomer in the obtained diluted emulsified solution.

Abstract: To provide a fluorine-containing rubber composition comprising (a-1) a non-perfluoro fluorine-containing rubber and (b-1) a fluorine-containing multi-segment polymer comprising an elastomeric fluorine-containing polymer chain segment and non-elastomeric fluorine-containing polymer chain segment, in which structural units of each of the elastomeric fluorine-containing polymer chain segment and the non-elastomeric fluorine-containing polymer chain segment comprise not less than 90% by mole of a perhalo olefin unit. The fluorine-containing rubber composition is capable of providing a clean sealing material for semi-conductor production apparatuses without using a filler.

Abstract: A peroxide-curable fluorine-containing elastomer composition comprising 100 parts by weight of a fluorine-containing block polymer comprising at least one elastomeric polymer chain segment and at least one non-elastomeric polymer chain segment in which the content of said non-elastomeric polymer chain segment is less than 5% by weight, 0.05 to 10 parts by weight, preferably 0.3 to 5 parts by weight, more preferably 1 to 5 parts by weight, of an organic peroxide, and 0.1 to 10 parts by weight, preferably 0.5 to 8 parts by weight, more preferably 0.5 to 5 parts by weight, of a polyfunctional co-crosslinking agent. This composition has improved processing properties during curing and molding, while it has good tensile properties, heat resistance, oil resistance and high temperature sealing properties comparable to those of conventional peroxide-curable fluorine-containing elastomer compositions.

Abstract: A fluorine-containing triallyl isocyanurate of the formula [I]: wherein at least one of X and Y is a fluorine atom, and the other is a hydrogen atom or a fluorine atom, exhibits good curing properties even when it is used as a crosslinking aid for elastomers which are required to have good heat resistance, such as in particular, fluororubbers, and provides cured materials having good mechanical properties and heat resistance.

Abstract: A fluorine-containing elastomeric copolymer comprising 55 to 62 mole % of repeating units derived from tetrafluoroethylene and 38 to 45 mole % of repeating units derived from perfluoro(methyl vinyl ether) which is obtained by radically polymerizing the monomers in the presence of a diiodide compound of the formula: RI.sub.2 in which R is a saturated fluorohydrocarbon or chlorofluorohydrocarbon group having 1 to 16 carbon atoms, or a hydrocarbon group having 1 to 3 carbon atoms and which has a Mooney viscosity (ML.sub.1+10 100.degree. C.) in the range between 20 and 150. This copolymer has an excellent compression set at high temperature, which is an important property for sealing members.

Abstract: The present invention provides the fluorine-containing elastic copolymer which is excellent in molding processability, particularly molding stability and further vulcanization properties, flowability at molding and compression set of a vulcanized rubber. The copolymer is prepared through emulsion polymerization of vinylidene fluoride and at least one of other monomers in two polymerization stages by using a water-soluble radical polymerization initiator in a very small amount of 0.001 to 0.03% by weight based on the total weight of copolymers prepared in the two stages and an oil-soluble radical polymerization initiator. The present invention also provides a process for preparation thereof and a vulcanizable composition containing the same.

Abstract: Polytetrafluoroethylene molding powder which comprises 0.01 to 1% by weight of a perfluoro(vinyl ether) unit and which has a heat of crystallization of 18.0 to 25.0 J/g. The molding powder provides a molded article which has a flex life of not less than 7 million cycles, a creep resistance (total deformation at 200.degree. C.) of not more than 20%, and a creep resistance (total deformation at 25.degree. C.) of not more than 15%. The polytetrafluoroethylene molding powder which is excellent in both creep resistance and flex fatigue resistance is provided as a molding material for parts which are repeatedly bent such as pump.

Abstract: A copolymer comprising 0.005 to 1.5 mole % of repeating units derived from an iodine-containing fluorinated vinyl ether, 40 to 90 mole % of repeating units derived from vinylidene fluoride, 3 to 35 mole % of repeating units derived from perfluoro(methyl vinyl ether), optionally up to 25 mole % of repeating units derived from hexafluoropropylene and optionally up to 40 mole % of repeating units derived from tetrafluoroethylene, which is obtained by polymerizing the above monomers in the presence of a diiodide compound, contains iodine atoms introduced in the copolymer from the diiodide compound and the iodine-containing fluorinated vinyl ether in amounts of 0.01 to 1 wt. % and 0.01 to 2 wt. %, respectively, and has a Mooney viscosity of 20 to 150.

Abstract: Polytetrafluoroethylene molding powder which comprises 0.01 to 1% by weight of a perfluoro(vinyl ether) unit and which has a heat of crystallization of 18.0 to 25.0 J/g. The molding powder provides a molded article which has a flex life of not less than 7 million cycles, a creep resistance (total deformation at 200.degree. C.) of not more than 20%, and a creep resistance (total deformation at 25.degree. C.) of not more than 15%. The polytetrafluoroethylene molding powder which is excellent in both creep resistance and flex fatigue resistance is provided as a molding material for parts which are repeatedly bent such as pump.