Claims
- 1. A toughened blend comprising:
- (a) 100 parts of poly(vinyl chloride), and
- (b) from about 5 to about 80 parts of an impact modifier comprised of at least 50 weight percent of units derived from a C.sub.2 -C.sub.8 alkyl acrylate and of at least 10 weight percent of units derived from a C.sub.1 -C.sub.4 alkyl methacrylate, the impact modifier formed from an assemblage of multi-stage cross-linked emulsion-prepared polymer particles, the first stage being a polymer predominately of units derived from one or more C.sub.2 -C.sub.8 alkyl acrylates and containing at least about 2 weight percent to about 10 weight percent of units derived from a copolymerizable monounsaturated carboxylic acid, the carboxylic acid being at least 40 % neutralized in the form of an ammonium salt at the time of formation of the second stage, and from about 0.2 to about 1.0 weight % of units derived from at least one unsaturated monomer having a plurality of addition polymerizable unsaturated groups, the second-stage polymer being formed in the presence of the first-stage polymer, the second-stage polymer being more than 50% of units derived from methyl methacrylate, the second-stage polymer being formed as cross-linked domains within the first polymer stage, the second-stage polymer being less than about 40 parts by weight of the total stages of the emulsion polymer particle, the second-stage polymer being free of units derived from maleimide or its N-substituted derivatives, and the second-stage polymer containing from about 0.5 to less than about 5 weight percent of units derived from at least one unsaturated monomer having a plurality of addition polymerizable unsaturated groups.
- 2. The blend of claim 1 wherein the second-stage polymer contains from about 0.5 to about 2.0 weight % of units derived from a unsaturated monomer having a plurality of addition polymerizable unsaturated groups.
- 3. The blend of claim 1 wherein the impact modifier additionally contains a third-stage polymer, the third-stage polymer containing no units derived from a polyunsaturated monomer having a plurality of addition polymerizable unsaturated groups and containing at least about 90 weight percent of units derived from methyl methacrylate.
- 4. A molded or extruded article formed from the blend of claim 1.
- 5. A molded or extruded article formed from the blend of claim 2.
- 6. A molded or extruded article formed from the blend of claim 3.
Parent Case Info
This application is a continuation of application Ser. No. 08/106,453 filed Aug. 13, 1993 now abandoned, which is a continuation-in-part application of U.S. application Ser. No. 931,760 filed Aug. 18, 1992, now abandoned.
US Referenced Citations (18)
Foreign Referenced Citations (3)
Number |
Date |
Country |
270865 |
Nov 1987 |
EPX |
295562 |
Dec 1988 |
EPX |
59247 |
Mar 1993 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
106453 |
Aug 1993 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
931760 |
Aug 1992 |
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