Claims
- 1. A high impact monovinylaromatic polymer compound consisting essentially of: (a) an impact resistant rubber modified monovinylaromatic polymer having optimum environmental stress crack resistance, said polymeric compound being polymerized in the presence of a rubber selected from the group consisting of natural rubbers, polybutadienes, isoprenes, copolymers of styrene with butadiene, copolymers of styrene with isoprene, and copolymers of styrene with isoprene, and copolymers of styrene with butadiene and isoprene; and (b) an ESCR enhancing additive consisting essentially of polyisobutylene having a viscosity range of 196-233 cst at 99° C., being added to said polymer compound in amounts of from about 1 percent to about 4 percent, by weight of said polymer compound.
- 2. The polymer compound of claim 1 wherein said polyisobutylene comprises 2.5 percent by weight.
- 3. The polymer compound of claim 1 wherein said monovinylaromatic polymer consists of polystyrene having a weight-average molecular weight of 170,000 to 285,000 and a number-average molecular weight of 10,000 to 120,000.
CROSS REFERENCED TO RELATED APPLICATION
[0001] This application is a continuation of a copending continuation application Ser. No. 08/828,206 filed Mar. 21, 1997, which is a continuation of a copending application, Ser. No. 08/547,824, filed Oct. 25, 1995, by B. Raghava Reddy, et al., under the same title.
Continuations (3)
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Number |
Date |
Country |
Parent |
09379813 |
Aug 1999 |
US |
Child |
10454135 |
Jun 2003 |
US |
Parent |
08828206 |
Mar 1997 |
US |
Child |
09379813 |
Aug 1999 |
US |
Parent |
08547824 |
Oct 1995 |
US |
Child |
08828206 |
Mar 1997 |
US |