Sytrenic polymer resins achieving improved gloss and impact resistance
AssigneeChevron Chemical Company
InventorKenneth E. Bowen
Life of this patent
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Abstract
A polystyrene based composition is provided having high impact strength and gloss. The gloss is particularly noted when the resin is molded into plastic articles, especially at relatively cooler temperatures, such as 80.degree. F. to 100.degree. F. The composition contains three resins. The first resin comprises polystyrene and rubber particles smaller than 1.0 micron, such as 0.2 to 0.6 microns. The second resin comprises polystyrene and rubber particles larger than 1.0 micron. The third resin preferably is a block copolymer of styrene and butadiene. Unexpectedly, the third resin improves the gloss achieved by the overall composition.
Claims12
A polystyrene based composition having high impact strength and high gloss, comprising:
- (a) a first resin comprising polystyrene and particles containing polybutadiene, wherein the particles have an average size less than 1.0 micron, and the polybutadiene content in the first resin is between 5 to 15 weight percent of the first resin;
- (b) a second resin comprising polystyrene and polybutadiene particles having an average particle size greater than 1.0 micron, and the amount of polybutadiene in the second resin is between 3 to 12 weight percent of the second resin;
- and
- (c) a third resin comprising a block copolymer of styrene and butadiene having a butadiene content of 65 to 80 weight percent.
Dependencies are inferred from the claim text.