초록 ▼

The present invention relates to compositions based on elastomeric polymers of vinylidene fluoride, hexafluoropropene and optionally tetrafluoroethylene suitable for providing microcellular foamed vulcanized articles by extrusion or compression molding. In the case of the production of extruded arti

The present invention relates to compositions based on elastomeric polymers of vinylidene fluoride, hexafluoropropene and optionally tetrafluoroethylene suitable for providing microcellular foamed vulcanized articles by extrusion or compression molding. In the case of the production of extruded articles based on vinylidene fluoride and hexafluoropropene copolymers, the compositions comprise: the copolymer, bisphenol AF, a quaternary phosphonium or aminophosphonium salt, azodicarbonamide, MgO, Ca(OH).sub.2, zinc stearate and a plasticizer, each of the components being contained in an exactly defined proportion.

대표청구항 ▼

[ We claim:] [1.] Compositions based on elastomeric copolymers containing from 78 to 83 moles % of vinylidene fluoride and from 17 to 22 moles % of hexafluoropropene, which are subjected to extrusion, are cured at temperatures ranging from 125.degree. to 150.degree. C. and lastly are post-cured at t

[ We claim:] [1.] Compositions based on elastomeric copolymers containing from 78 to 83 moles % of vinylidene fluoride and from 17 to 22 moles % of hexafluoropropene, which are subjected to extrusion, are cured at temperatures ranging from 125.degree. to 150.degree. C. and lastly are post-cured at temperatures ranging from 180.degree. to 260.degree. C. for 20-35 hours, with a raising time ranging from 5 to 14 hours, said compositions consisting essentially of______________________________________ a) an elastomeric copolymer as defined 100 parts by wg. above having a M.sub.L viscosity (1' + 10') at 121.degree. C. ranging from 25 to 50 Mooney degrees b) bisphenol AF about 0.5-1.0 parts by wg. c) quaternary phosphonium or aminophosphonium salt about 0.5-1.0 parts by wg. d) azodicarbonamide about 2.5-5.0 parts by wg. e) MgO about 1.0-2.0 parts by wg. f) Ca(OH).sub.2 about 1.0-3.0 parts by wg. g) zinc stearate about 1.0-3.0 parts by wg. h) polyoxyethylene glycol about 0-1.0 parts by wg. having an average molecular weight from about 3,000 to 5,000 i) plasticizer about 1.0-5.0 parts by wg.; ______________________________________ rein the quaternary phosphonium salt is a triphenylbenzylphosphonium salt and the quaternary aminophosphonium salt is a 1-chloro-N, N-diethyl-1,1-diphenyl-1(phenylmethyl) phosphoranamin salt, while the plasticizer is selected from the group consisting of the esters of fatty acids and of adipic acid, polyethers deriving from the polycondensation of ethylene oxide and/or propylene oxide, low molecular weight polyethylenes, dioctylphthalate, di(2-ethylhexyl) phthalate and other phtahalic acid derivatives having plasticizing properties, 5,8,11,13,16,19-hexaoxa-tricosane and the condensation products of derivatives of fatty acids and silicones on inorganic carriers.