CROSS-LINKABLE FLUOROELASTOMER COMPOSITION Russian patent published in 2000 - IPC

FIELD: polymer materials. SUBSTANCE: composition consisting of vinylidene difluoride/hexafluoropropylene copolymer, cross-linking agent, and accelerator is distinguished by that (i) copolymer, in which fluorine level is below 67%, content of vinylidene difluoride units is 40-68% and that of hexafluoropropylene units 25-50%, can also contain one or more ethylenically-unsaturated comonomers, number of ionic extremities in copolymer being 0.5; (ii) cross-linking agent and accelerator form adduct at molar ratio 1: (3-5), accelerator being onium organic compound and cross-linking agent being di- or polyhydroxy, di- or polythiol compound; (iii) adduct is prepared by melting reaction product of accelerator and cross-linking agent in indicated molar proportions or by melting 1:1 adduct added to required excess of cross-linking agent; (iv) content of accelerator as defined in (ii) ranges from 0.05 to 0.5 wt parts for 100 wt parts of copolymer. EFFECT: improved mechanical and elastomeric properties with good workability retained. 10 cl, 6 tbl, 8 ex