Patent ID: 6730741
Filing Date: 2004-05-04
Classification: C08L

Abstract:
A processing aid comprising:a copolymer (A) whose mean weight molecular weight (Mw) measured with gel permeation chromatography is in the range of from 700,000 to 2,000,000, and molecular weight distribution (Mw/Mn) is 3.0 or smaller, which is obtained by copolymerizing a monomer mixture comprising 70 to 90% by weight of methyl methacrylate, 10 to 30% by weight of acrylate or methacrylate other than methyl methacrylate, and 3% by weight or less of a different type of monomer capable of being copolymerized with those monomers; and a copolymer (B) whose mean weight molecular weight (Mw) measured with gel permeation chromatography is in the range of from 10,000 to 500,000, which is obtained by copolymerizing a monomer mixture comprising at least 30 to 50% by weight of methyl methacrylate, a monomer other than a polyfunctional monomer and having as constitutional units at least one type other than methyl methacrylate, and 2% by weight or less of polyfunctional monomers, wherein copolymer (A) and copolymer (B) are present in a ratio of 100 parts by weight of copolymer (A) to 0.5-100 parts by weight of copolymer (B).