Impact modifier compositions for rigid PVC compositions of hydrocarbon rubbers and chlorinated polyethylene
The present invention is specifically directed to improved polyvinyl chloride compositions having excellent impact strength. In particular, the impact resistant composition comprises a vinyl chloride polymer and 2-8 parts of an impact modifier composition comprising at least one ethylene/alpha-olefin copolymer and at least one chlorinated olefin polymer per 100 parts of the vinyl chloride polymer. Preferably the impact modifier composition comprises less than 1 part of the ethylene/alpha-olefin copolymer and the ratio of said copolymer to the total modifier composition is less than 25%.
1. A impact resistant vinyl chloride polymer composition comprising 2-8 parts per 100 parts vinyl chloride polymer of:
a) at least one ethylene/alpha-olefin copolymer and
b) at least one chlorinated polyolefin
wherein said impact resistant composition contains less than 1 part ethylene/alpha olefin copolymer and the ratio of ethylene/alpha olefin copolymer to the total of both ethylene/alpha olefin copolymer and chlorinated polyolefin is less than 25%.
2. The composition of claim 1 wherein the alpha-olefin is a C 3 -C 8 olefin.
3. The composition of claim 1 wherein the ethylene/alpha-olefin copolymer is selected from the group consisting of ethylene/propylene, ethylene/butene, ethylene/hexene, ethylene/octene, ethylene/propylene/5-ethylidene-2-norbornene, and ethylene/butene/5-ethylidene-2-norbornene copolymers.
4. The composition of claim 1 wherein the chlorinated polyolefin is chlorinated polyethylene.
5. The composition of claim 1 wherein the chlorinated polyolefin is a chlorinated copolymer of ethylene and one or more C 3 -C 8 alpha-olefins.
6. An article comprising a pipe, profile, sheet, or vinyl siding made from an impact resistant vinyl chloride polymer composition according to any of claims 1 - 5 .