Nippon Mektron Limited

Nippon Medtron, Limited

Okimasa Yamada

Takehiro Sonoi

Takashi Enokida

Toshimasa Sagawa

Tetsuya Mizuno

Yasunori Yanai

Jun Kanega

Jishan Jin

Hideo Aoki

Process for producing fluorinated copolymer, fluorinated copolymer, crosslinkable composition containing same and sealant

A fluorine-containing copolymer composition comprising a fluorine-containing elastomer and a fluororesin, both having reaction sites capable of reacting with a common crosslinking agent gives crosslinking molding products having distinguished roll processability, moldability and mechanical strength, where crosslinking molding is carried out preferably by a peroxide crosslinking system or polyol crosslinking system, and the low temperature characteristics is considerably improved when the fluororesin has a softening point of not less than 120.degree. C.

Flourine-containing copolymer composition

A fluorine-containing graft copolymer produced by copolymerizing at least two kinds of monomers selected from the group consisting of fluorinated monomers and propylene in the presence of a saturated iodine-containing compound or an iodine and bromine-containing compound, and further graft copolymerizing the resulting copolymer with tetrafluoroethylene and polyfluorovinyl ether represented by the general formula:

Process for producing fluorine-containing graft copolymer

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.

Process for producing hexafluoroacetone or its hydrate

A fluorine-containing elastomer composition comprising a fluorine-containing elastomer, at least one of oxide and hydroxide of divalent metal, a polyhydroxyaromatic compound, and a quaternary ammonium salt compound represented by the general formula: ##STR1## wherein R' is a piperidino or a pyrrolidinyl radical, and if desired, further containing 1,8-diazabicyclo-[5,4,0]-undec-7-ene or 1,5-diazabicyclo[4,3,0]-non-5-ene, has good storage stability as green elastomer composition and gives distinguished physical properties to the vulcanized products.

Fluorine-containing elastomer composition

Hexafluoracetone 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.

A fluorine-containing elastomer composition which comprises (a) a fluorine-containing elastomer, (b) at least one of divalent metal oxide and hydroxide, (c) a polyhydroxyaromatic compound and (d) a complex compound of 1,8-diazobicyclo[5,4,0]undec-7-ene or diazabicyclo[4,3,0]non-5-ene and a divalent metal chloride, has a good stock storage stability and can produce a vulcanized product with improved vulcanized product properties and compression set.

When a molded, porous carbon article for use as a sliding material for bearing, etc. is maintained in a stream or atmosphere of a fluorine gas or a fluorine gas diluted with an inert gas, the surface of the article is treated with the fluorine gas, and considerable lowering of friction coefficient and considerable reduction in abrasion at the sliding can be attained.

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Kitaibaraki, Japan

Okimasa Yamada