Olefinic impact modifiers for, and blends with, thermoplastic polyester resins
AssigneeCopolymer Rubber & Chemical Corporation
InventorsCharles F. Pratt, Shrikant V. Phadke, Errol Olivier
Life of this patent
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Abstract
Thermoplastic polyester, copolyester and polyblend molding compositions impact-modified by glycidyl methacrylate grafted EPDM exhibit high impact strength combined with good knit-line characteristics, when the grafted comonomer content exceeds 2 percent by weight in the impact modifier, it has a gel content in the range of from about 10 to about 80 weight percent.
Claims12
An impact modifier for improving the knit-line strength and impact strength of polyester resins when melt compounded therewith comprising the reaction product of an EPDM rubber in the molten phase with at least 2 percent based on the weight of the rubber of a graft monomer selected from the group consisting of an epoxy functional ester of acrylic acid and an epoxy functional ester of alkyl acrylic acid in the presence of at least 0.3 percent by weight based on the rubber of a free radical initiator, the reaction product having a gel content in the range of from about 10 to about 80 percent.
The method for producing an impact modifier for improving the knit line strength and impact strength of polyester resins when melt compounded therewith comprising reacting an EPDM rubber in the molten phase with at least 2 percent based on the weight of the rubber of a graft monomer selected from the group consisting of an epoxy functional ester of acrylic acid and an epoxy functional ester of alkyl acrylic acid in the presence of at least 0.3 percent by weight based on the rubber of a free radical initiator, to produce a reaction product having a gel content in the range of from about 10 to about 80 percent.
Dependencies are inferred from the claim text.