Nippon Mektron Limited

Nippon Moktron Limited

Masatoshi Abe

Akihiro Naraki

Haruyoshi Tatsu

Jun Okabe

Shin Okamoto

Yuichi Yamamoto

Masashi Fukazawa

Yoshiaki Ebina

Seiichi Nakamura

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.

Process for purifying perfluoro(propylvinylether)

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.

Crosslinkable, fluorine-containing elastomer composition

A white pigment-containing, peroxide-vulcanizable, fluorine-containing elastomer composition, which comprises a fluorine-containing elastomer containing at least one of iodine and bromine in the molecule, an organic peroxide, a polyfunctional compound and ultra fine white carbon particles having a pH of 9 to 12 as an aqueous 4.about.5% by weight solution gives a vulcanized product with an improved compression set.

Peroxide-vulcanizable, fluorine-containing elastomer composition

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).

Process for producing peroxide-vulcanizable, fluorine-containing

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.

Fluorine-containing block copolymer

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.

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.

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:

Process for producing fluorine-containing elastic copolymer

This invention relates to a fluorine containing polymer as well as a curable composition containing the polymer and an organic peroxide. The fluorine containing polymer consists of a copolymer of (1) 3-bromoperfluoropropyl perfluorovinyl ether or 2-bromoperfluoropropyl perfluorovinyl ether, and (2) a fluorine containing monomer of 2 to 8 carbon atoms copolymerizable with said perfluoropropyl perfluorovinyl ether, the content of said perfluoropropyl perfluorovinyl ether in said copolymer being less than 5 mol %.

Fluorine containing polymers and compositions containing same

A peroxide-vulcanizable, fluorine-containing elastomer having distinguished processability, vulcanization characteristics and physical properties of vulcanized products can be obtained by polymerization of fluorine-containing olefins having 2 to 8 carbon atoms in the presence of a bromine or iodine-containing aromatic or perfluoroaromatic compound, polysubstituted with (1) bromine atoms or bromoalkyl groups (2) iodine atoms or iodoalkyl groups.

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Kitaibaraki, Japan

Masatoshi Abe