摘要 |
Thermoplastic elastomer resins are described which comprise vinyl halide grafted to crosslinked acrylic latex particles comprising predominantly acrylate-containing, crosslinked polymer chains derived from (A) at least one acrylate monomer of the formula CH2=C(R1)C(O)OR2(I) wherein R1 is hydrogen or methyl; and R2 is an alkyl group containing from 1 to 29 carbon atoms, an alkoxy alkyl or alkyl thioalkyl group containing from 2 to about 7 carbon atoms, or a cyano alkyl group containing from 2 to about 7 carbon atoms; and (B) at least one alpha, beta-unsaturated dicarboxylic acid, provided that the dicarboxylic acid repeating units are optional when the TPE resin contains less than about 35% by weight of vinyl halide. An improved process is described for preparing the crosslinked acrylic latexes utilized in the preparation of TPEs, and a process is described for preparing TPEs of the invention which comprises (A) preparing a crosslinked acrylic latex by polymerizing in water a mixture comprising at least one acrylate monomer of Formula I, and at least one multi-functional crosslinking monomer, an initiator, and from 0 to about 20 phm of at least one alpha, beta-unsaturated dicarboxylic acid while delaying the polymerization of at least a portion of the crosslinking monomer until at least a portion of the acrylic monomer has polymerized; (B) grafting a vinyl halide monomer to the crosslinked latex particles prepared in step (A) in water in the presence of a second initiator to form aqueous mixture containing a TPE resin; (C) recovering the TPE resin from the aqueous mixture; and (D) compounding with suitable additives to produce useful thermoplastic elastomers.
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