| 摘要 |
?0,622 BLENDS OF POLYMERS, PARTICULARLY POLYCARBONATES, ACRYLATE-MODIFIED FUBBER COMPOSITIONS AND ADDITIONAL POLYACRYLATES The modified rubber compositions comprise by weight about 15-60% of a highly saturated aliphatic rubber such as ethylene-propylene-diene rubber, about 25-80% of preferably non-nitrogenous acrylate monomer units; and less than about 5% multi-functional monomer units. The compositions exist as amorphous heterogeneously dispersed phases. The first phase comprises the copolymer rubber to which polymers of at least 10%, preferably 20%, and more preferably 30% of the other monomer units are grafted. The second phase comprises the other monomers polymerized as homo and copolymers, not grafted to the rubber. Greater than 10% and preferably 20% of the monomer units other than rubber are grafted to the rubber. The number average molecular weight of the grafts is between 10,000 and 80,000 daltons. The modified rubber composition, additional, preferably non-nitrogenous, polyacrylate polymer, and another polymer are mixed together to form a polymer blend having higher impact strength and other important properties. The other polymers are often more expensive and usually have some advantageous property compared to polyacrylate. Other polymers disclosed are: polycarbonates, SAN, polystyrene, polyvinylchloride, polypropylene, polyester, styrene maleic anhydride, chlorinated polyethylene, polyethylene terephthalate, nylon and ABS. Polycarbonate blends preferably comprise a total of at least 35% and up to 65% polyacrylate. The proportion of rubber used to form the graft rubber composition to the total graft rubber composition and polyacrylate polymer in polycarbonate blends is in the range of approximately 2 to less than 30% by weight and preferably no greater than 25%. The modified rubber composition is present in polycarbonate blends in the range of approximately 6% to 50% by weight. The added polyacrylate preferably has a molecular weight greater than 80,000 daltons.
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