| 摘要 |
<p>Non-bleeding predispersed compsn. useful for dispersing a peroxide vulcanising agent or coagent into a rubber or plastic stock, comprises (A) 20-70 wt.% of a peroxide vulcanising agent or coagent and (B) a multi-stage graft copolymer comprising (1) 70-90 wt.% of a hard portion made by graft polymerising (a) one or more monomers chosen from lower alkyl methacrylates, styrene and mixts. of these and (b) a small but effective amt. of a crosslinking agent for the monomer(s), in any order onto (2) from 10-30 wt.% of a rubbery portion comprising a (co)polymer made by polymerising (a) at least one monomer chosen from butadiene and lower alkyl acrylates or (b) a mixt. of monomers chosen from styrene and butadiene or acrylonitrile and butadiene. - Suitable peroxide vulcanising agents are dicumyl peroxide, alpha, alpha'-bis(t-butylperoxy) -diisopropylbenzene, t-butyl cumyl peroxide, 2,5-dimethy- -2,5-bis(t-butylperoxy)hexyne-3 and 2,5-bis(t-butylperoxy)- 2,5-dimethylhexane. Suitable peroxide vulcanising agent coagents are triallyl isocyanurate, triallyl cyanurate, triallyltrimellitate, trimethylolpropane triacrylate and trimethylolpropane trimethacrylate. - Compsns. are non-dusting and are easy to handle, and present less health hazards to operatives. They allow accurate dispensing of vulcanising agent into the rubber compsns. and disperse easily into the compsn. during compounding. (0/0) EPAB- EP--92244 B A non-bleeding, predispersed composition useful for dispersing a peroxide vulcanising agent or coagent into a rubber or plastic stock comprising (A) from 20 to 70 percent by weight of a peroxide vulcanising agent or coagent, and (B) a multi-stage graft copolymer comprising (1) from 70 to 90 percent by weight of a hard portion made by graft polymerising (a) a monomer or monomers selected from the group consisting of lower alkyl methacrylates, styrene, and mixtures thereof, and (b) a small but effective amount of a cross-linking agent for said monomer or monomers, in any order onto (2) from 10 to 30 percent by weight of a rubbery portion comprising a polymer or copolymer made by polymerising (a) at least one monomer selected from the group consisting of butadiene and lower alkyl acrylates or (b) a mixture of monomers selected from the group consisting of styrene and butadiene, and acrylonitrile and butadiene. (23pp)</p> |
