| 摘要 |
PURPOSE: To enable extrusion processing at a high speed without generating melt fracture by adding a specific polyolefin /polymethacrylate ester graft copolymer to linear low density polyethylene. CONSTITUTION: A graft copolymer is prepared by grafting at least one chain being a polymer having a wt. average mol.wt. larger than about 20,000 and present in a wt. ratio of about 1:9-4:1 with respect to polyolefin to a non-polar polyolefin backbone in a soln. The grafted polymer is guided from at least about 80 wt.% of a methacrylic acid ester monomer represeted by the formula CH2 =C(CH3 ) COOR (wherein R is alkyl, substd. aryl or substd. alkaryl) and below about 20 wt.% of an acrylic or styrenic monomer capable of being copolymerized with the methacrylic acid ester monomer. The concn. of the graft copolymer achieving the reduction of melt fracture becomes about 0.5-2%. When other characteristics are modified by the graft copolymer, the graft copolymer is set to higher concn. |
