PURPOSE: To obtain a graft copolymer imparting the high tensile modulus of elasticity and sag resistance without increasing melt viscosity by gradually adding a methacrylic ester monomer to a non-polar polyolefin soln. along with an initiator and subsequently removing a solvent to mix the monomer with polyolefin.
CONSTITUTION: A non-par polyolefin (A) selected from PP, PE, polybutylene, a copolymer of them and a copolymer of each of them and a small amt. of 1-alkene and (meth)acrylic acid is introduced into an inert solvent-containing container and this polyolefin mixture (B) is heated to polyolefin melting temp. and about 80% or more by wt. of the total monomer of a methacrylic ester monomer represented by formula [wherein R is (substituted) alkyl or (substitued) aryl] and about 20 wt.% of an acrylic or styrene monomer (C) are added to the polyolefin soln. under stirring and an initiator (D) generating small and constant radical flux over a time sufficient to generate a methacrylate chain polymer with a mol.wt. of about 20,000-1000,00 having a covalent bond is added to this polyolefin and a graft copolymer (E) is obtained by removing the solvent to isolate a graft copolymer concentrate.
WORK WILLIAM JAMES (US)
GRAHAM ROGER KENNETH (US)
BORTNICK NEWMAN (US)
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