Abstract: A fluorine-containing-copolymer composition comprises a novel terpolymer of tetrafluoroethylene-perfluoro (methylvinylether)-1,1,3,3,3-pentafluoropropene and dialkali metal salt of bisphenol compound gives a vulcanization product having a low compression set.

Abstract: Tetrafluoroethylene-perfluorovinylether copolymer having a specific melt viscosity of 30.times.10.sup.4 to 200.times.10.sup.4 poises at 372.degree. C., which comprises 99% to 90% by weight of tetrafluoroethylene and 1% to 10% by weight of perfluoro(ethyl vinyl ether) can produce a film or sheet having good resistance to flex fatigue by molding.

Abstract: A vulcanizable, fluorine-containing elastomer composition, which comprises a fluorine-containing elastomer copolymerized with chlorotrifluoroethylene, (A) a salicylaldo-imino copper complex having the following chemical formula as a cross-linking agent: ##STR1## (B) at least one of a divalent metal oxide and hydroxide as an acid receptor, and (C) a polyfunctional unsaturated compound as a cross-linking agent have a high vulcanization rate and good physical properties in the normal state of vulcanization product.

Abstract: A composition for low hardness, fluorine-containing rubber comprising solid fluorine-containing rubber, liquid fluorine-containing rubber, an aliphatic amine having an alkyl group having at least 8 carbon atoms and a perfluoropolyether has a good mold releasability at the vulcanization molding and can produce a vulcanized product having a JIS A hardness, according to JIS K-6301, of not more than 50 and less adhesiveness to a metal.

Abstract: By using salicylaldoimino copper complex having the following formula as a cross-linking agent for a fluorine-containing elastomer containing at least one of iodine and bromine in the molecule, a vulcanization product with an improved heat resistance can be obtained and generation of harmful substances such as methyl iodine, methyl bromine, etc.

Abstract: An acrylic elastomer capable of giving a vulcanization product having a distinguished tensile strength and a good stretching even by cross-linking with an organic peroxide can be obtained by using an organic peroxide having a non-conjugated double bond as a polymerization initiator in polymerization of at least one of (a) alkyl acrylates having an alkyl group of 1 to 8 carbon atoms and (b) alkoxyalkyl acrylates having an alkoxylalkyl group of 2 to 8 carbon atoms.

Abstract: A vulcanizable acrylic rubber composition comprising an acrylic rubber containing an active halogen group and a carboxyl group, trithiocyanuric acid, and a metal salt of dithiocarbamic acid alone or together with thiuram sulfide gives a vulcanized product having very good compression set and tensile strength even if the secondary vulcanization is omitted.

Abstract: Pure perfluoro(propylvinylether) is obtained by extractive distillation of crude perfluoro(propylvinylether) containing a hydrogen fluoride adduct of perfluoro(propylvinylether), which is obtained by gas phase or liquid phase thermal decomposition of perfluoro(2-propoxypropionyl)fluoride, in the presence of a ketone having a boiling point of 100.degree. C. of higher.

Abstract: A cross-linkable, fluorine-containing elastomer composition comprising a fluorine-containing elastomer containing at least one of iodine and bromine in the molecule, an organic peroxide having a peroxy group --O--O--C(CH.sub.3).sub.2 R, where R is a lower alkyl group, in the molecule and an activation energy of not more than 34.0 Kcal/mole and another organic peroxide having the same peroxy group as defined above in the molecule and an activation energy of less than 34.0 Kcal/mole as cross-linking agents for the elastomer has less generation of CH.sub.3 I or CH.sub.3 Br at the decomposition of the organic peroxides without any substantial decrease in the compression set of the vulcanization products.

Abstract: Aphidicolin is produced with a high productivity by culturing microorganisms belonging to the genus Verticillium, for example, Verticillium sp FERM BP-3430, in a culture medium, thereby forming and accumulating aphidicolin therein and recovering the aphidicolin therefrom.

Abstract: Acrylic elastomer obtained by copolymerization of an epoxy group-containing vinyl monomer and an .alpha., .beta.-unsaturated carboxylic acid aryl ester can produce vulcanization products having good compression set and heat resistance when vulcanized together which (1) a cyanuric acid and (2) a quaternary ammonium salt or phosphonium salt as cross-linking agents without secondary vulcanization.

Abstract: A vulcanizable acrylic elastomer composition, which comprises copolymers of at least one of (a) an alkyl acrylate having an alkyl group having 1 to 8 carbon atoms and (b) an alkoxyalkyl acrylate having an alkoxyalkyl group having 2 to 8 carbon atoms, (c) an epoxy group-containing vinyl monomer and (d) .alpha.,.beta.-unsaturated carboxylic acid aryl ester, and (1) a disphenyl phthalate and (2) a quaternary ammonium salt or a phosphonium salt, and (3) at least one of a urea and a guanidine as cross-linking agents.

Abstract: An acrylic elastomer capable of giving a vulcanization product having a distinguished tensile strength and a good stretching even by cross-linking with an organic peroxide can be obtained by using an organic peroxide having a non-conjugated double bond as a polymerization initiator in polymerization of at least one of (a) alkyl acrylates having an alkyl group of 1 to 8 carbon atoms and (b) alkoxyalkyl acrylates having an alkoxyalkyl grouop of 2 to 8 carbon atoms.

Abstract: A cross-linkable fluorine-containing elastomer composition comprising a fluorine-containing elastomer containing at least one of iodine and bromine in the molecule, an organic peroxide having a peroxy group --O--O--C(CH.sub.3).sub.2 R, where R is a lower alkyl group, in the molecule and an activation energy of not more than 34.0 Kcal/mole and another organic peroxide having the same peroxy group as defined above in the molecule and an activation energy of less than 34.0 Kcal/mole as cross-linking agents for the elastomer has less generation of CH.sub.3 I or CH.sub.3 Br at the decomposition of the organic peroxides without any substantial decrease in the compression set of the volcanization products.

Abstract: A fluorine-containing elastomer capable of giving a primary vulcanization product with a good permanent set through peroxide vulcanization is produced by homopolymerization or copolymerization of a fluorine-containing olefin having 2 to 8 carbon atoms in the presence of an iodine and bromine-containing compound represented by the general formula RBrnIm, wherein R represents a fluorohydrocarbon group, a chlorofluorohydrocarbon group, a chlorohydrocarbon group or a hydrocarbon group, and n and m are integers of 1 and 2, and a small amount of perfluoro(unsaturated compound) which is iodotrifluoroethylene, perfluoro(bromoalkylvinylether) or perfluoro(iodoalkylvinylether).

Abstract: CF.sub.2 .dbd.CF.sub.2 and CF.sub.3 OCF.dbd.CF.sub.2 are subjected to copolymerization reaction in the presence of an organic compound containing at least one of iodine and bromine, and then CF.sub.2 .dbd.CF.sub.2 and CH.sub.2 .dbd.CF.sub.2 are supplied to the reaction system to continue the polymerization reaction.The thus obtained fluorine-containing block copolymer is of a low vinylidene fluoride content type and has a good solvent resistance.

Abstract: A crosslinkable, fluorine-containing elastomer composition containing an organic peroxide having a peroxy group --O--O--C (CH.sub.3).sub.2 R, where R is a lower alkyl group, in the molecule and an activation energy of not more than 34.0 Kcal/mole as a crosslinking agent for a fluorine-containing elastomer containing at least one of iodine and bromine. The organic peroxide reduces an amount of CH.sub.3 I or CH.sub.3 Br to be generated at its decomposition.

Abstract: Hexafluoroacetone or its hydrate is produced in a higher yield than that of the conventional process (1) by oxidizing a heptafluoroisobutenyl ether with ozone or (2) by thermally decomposing an octafluoroisobutyl ether or a heptafluoroisobutenyl ether in the presence of oxygen and an activated carbon catalyst.

Abstract: A fluorine-containing elastomer capable of giving a vulcanized product with a good permanent set through peroxide vulcanization is produced by homopolymerization or copolymerization of a fluorine-containing olefin having 2 to 8 carbon atoms in the pressence of an iodine and bromine-containing compound represented by the general formula RBrn Im, where R represents a fluorohydrocarbon group, a chorofluorohydrocarbon group, a chlorohydrocarbon group or a hydrocarbon group, and n and m are integers of 1 and 2, and a small amount of 1,1-difluoro-2-bromoethylene.

Abstract: A fluorine-containing elastic copolymer with distinguished low temperature characteristics, comprising (a) about 30 to about 80% by mole of tetrafluoroethylene, (b) about 5 to about 60% by mole of perfluoro(lower alkyl vinyl ether) and (c) a perfluoroether compound represented by following general formula:CF.sub.2 .dbd.CFOCF.sub.2 CFXORfwherein X: F or --CF.sub.3 and Rf: --CnF.sub.2n+1, is obtained by copolymerizing the (a) component, the (b) component and the (c) component in the presence of a radical polymerization initiator.