摘要 |
PURPOSE:To prevent the evolution of foreign taste and odor by heating a PP resin composition formed by mixing PP with compounds A and B represented by specific formulae at a temperature in a given range subsequent to its melting and extrusion-molding. CONSTITUTION:A PP resin composition is prepared by mixing 100 pts.wt. of PP with 0.01-1.0 pt.wt. of a compound A (a phenolic antioxidant) represented by formula I, such as pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4 -hydroxyphenyl)propionate], 0.01-1.0 pt.wt. of a compound B (a phosphorus antioxidant) represented by formula II, such as tris(2,4-di-tert-butylphenyl) phosphite, and other additives. The obtained composition is molded into a film or sheet by a melt extruder and processed into a bag or cup, which is heated at 40-160 deg.C by hot air and subjected to a heat treatment such as vacuum heating or steam treatment. Thus, a wrapping material with less evolution of foreign taste and odor is provided. |