| 摘要 |
1336492 Polyolefin compositions U C B 30 June 1971 [3 July 1970] 30648/71 Heading C3P [Also in Division B5] Compositions which may be homogenized and extruded to form paper substitutes comprise (A) 30 to 94À8 weight per cent of a homopolymer or copolymer of ethylene, propylene or butene or mixture thereof having a melt index of less than 1 dg/min; (B) 0À1 to 35 weight per cent of at least one polymer incompatible with (A) which forms a brittle film when extruded alone and has a melt index of less than 10 dg/min, selected from polymers of styrene, halo-alkyl styrenes, vinyl and vinylidene chlorides and C 1-3 alkyl (meth) acrylates; (C) 0À1 to 35 weight per cent. of a macromolecular compatibilizer for (A) and (B) and selected from (1) copolymers of at least one of ethylene, propylene and butene with at least one of isobutylene, butadiene and isoprene, and (2) at least one homopolymer of ethylene, propylene or butene mixed with at least one homopolymer of isobutylene, butadiene or isoprene, (C) having a melt index of at most 2 dg/min; (D) 5 to 45 weight per cent of mineral filler having a particle size below 50 microns; and (E) 0 to 10 weight per cent of antioxidants, thermal stabilizers, brighteners, colourants, antistatic agents and/or lubricants. Many suitable materials are specified and examples describe the preparation of paper substitutes by mixing and extruding compositions comprising (1) high density polyethylene, high impact polystyrene containing 10 per cent polybutadiene, polyethylene/polyisobutylene mixture, titanium dioxide, calcium carbonate and paraffin oil; (2) high density polyethylene, styrene/butadiene copolymer, ethylene/isobutylene copolymer, titanium dioxide, calcium carbonate and C 12-18 alkylamines; and (3) high density polyethylene, isotactic polypropylene, polystyrene/polybutadiene mixture, polyethylene/butyl rubber mixture, calcium carbonate, titanium dioxide, paraffin oil and optical brightener. |
