| 摘要 |
<p>A process for producing a fluoroelastomer composed of vinylidene fluoride units and other fluoromonomer units copolymerizable therewith by suspension polymerization, which comprises: (1) dispersing the above monomers in 100 parts by weight of an aqueous medium containing 0.001-3 parts by weight of a suspension stabilizer, (2) using a polymerization initiator solution prepared by diluting 0.001-5 parts by weight of an oil-soluble organic peroxide in a concentration of 0.1-75 % by weight with a halogen-fee water-soluble hydrocarbon solvent represented by the general formula R-OH, R2-COO-R1 or R1-CO-R3 (wherein R1 and R3 represent each methyl or tert-butyl, and R2 represents hydrogen, methyl or tert-butyl), and (3) conducting the suspension polymerization at 45-70 DEG C. The process provides a fluoroelastomer which has excellent resistances to heat, oil and chemical, a reduced compression set and a good releasability, and little stains a mold. Further it can dispense with the use of an ozonosphere-depleting chlorofluorocarbon solvent and facilitates the recovery of the monomers and solvent.</p> |
