摘要:
A fluorine-containing elastomer comprising vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene having a high fluorine content (e.g. at least 68% by weight) can be vulcanized with a polyol-based cross-linking agent by further copolymerizing 2H-pentafluoropropylene into the elastomer, whereby the resulting vulcanization products having improved characteristics such as rheological properties, normal state physical properties and compression set can be obtained. Vulcanization products obtained by vulcanization with a polyol-based cross-linking agent and a quaternary onium salt compound have a good permeation resistance to fuel oil as a result of a permeation test with a mixed solvent of gasoline/methanol in a volume ratio of 85/15.
摘要:
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.
摘要:
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 %.
摘要:
A vulcanization promoter for fluorine-containing elastomers prepared by (1) allowing 1.01 to 1.15 moles of a quaternary phosphonium salt to react with one mole of monoalkali metal salt of bisphenol AF in alcohol, (2) allowing 2.02 to 2.30 moles of a quaternary phosphonium salt to react with one mole of a dialkali metal salt of bisphenol AF in alcohol, (3) allowing one mole each of an alkali metal alkoxide and bisphenol AF to react with 1.01 to 1.15 moles of a quaternary phosphonium salt in alcohol or (4) subjecting one mole of bisphenol AF, 1.01 to 1.15 moles of a quaternary phosphonium salt and one mole of an alkali metal alkoxide to reaction in alcohol, each followed by further addition of the bisphenol AF thereto, or (5) allowing 1.01 to 1.15 moles of a quaternary phosphonium salt to react with one of 1/4alkali metal salt of bisphenol AF in alcohol gives much more improved vulcanization characteristics such as vulcanization speed, etc. while maintaining advantageous properties such as distinguished normal state physical properties as observed in case of vulcanization promoters of bisphenol AF-quaternary phosphonium salt series.
摘要:
Filler-containing, cross-linked, vulcanized fluorine rubber waste is regenerated by treatment with at least one of CH.sub.3 SO.sub.3 H, ClSO.sub.3 H, CF.sub.3 SO.sub.3 H and fuming sulfuric acid, followed by dissoluting into a solvent and separating solvent-insoluble filler therefrom, whereby revulcanizable fluorine rubber is recovered from the fluorine rubber waste, almost irrespective of types of cross-linking systems used for formation of cross-linked, vulcanized fluorine rubber.
摘要:
A fluorine rubber composition comprising a fluorine rubber and a polyfluoroalkyl group-containing block isocyanate compound represented by the following general formula: Rf(CH.sub.2)nXCONHRNHCOO(N.dbd.C--R.sup.2)mR.sup.1 where Rf is a polyfluoroalkyl group having 4 to 20 carbon atoms; R is a divalent organic group; R.sup.1 is a lower alkyl group or phenyl group; R.sup.2 is a lower alkyl group; X is NH or O; n is an integer of 1 to 4 and m is 0 or 1, has a good vulcanization bond to metals without any substantial decrease in the rubber stretchability properly owned by the fluorine rubber.
摘要:
A fluorine rubber composition comprising a fluorine rubber and a polyfluoroalkyl group-containing block isocyanate compound represented by the following general formula:Rf(CH.sub.2)nXCONHRNHCOO(N.dbd.C--R.sup.2)mR.sup.1where Rf is a polyfluoroalkyl group having 4 to 20 carbon atoms; R is a divalent organic group; R.sup.1 is a lower alkyl group or phenyl group; R.sup.2 is a lower alkyl group; X is NH or O; n is an integer of 1 to 4 and m is 0 or 1, has a good vulcanization bond to metals without any substantial decrease in the rubber stretchability properly owned by the fluorine rubber.
摘要:
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.
摘要:
Disclosed is a vulcanizable fluororubber composition comprising (a) a tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, (b) an organic peroxide, (c) a co-crosslinking agent and (d) hydrotalcite. The copolymer (a) preferably contains an iodine atom or a bromine atom. The vulcanizable fluororubber composition preferably further comprises carbon black or titanium oxide. When the vulcanizable fluororubber composition is vulcanized, the resulting vulcanizate has excellent compression set and is relatively non-toxic.
摘要:
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.