| 摘要 |
A composition comprises a major proportion of polypropylene and a minor proportion of polypropylene grafted with a vinyl compound in such a proportion that the weight of grafted monomer is from 1 to 8% (or the weight of vinyl pyridine is from 0.5 to 10% in the case of a mixture of a vinylpyridine and an acrylic ester) based on the weight of the compositions, said grafted polypropylene having from 5 to 80% by weight of graft monomer based on the weight of polypropylene and being prepared by subjecting powdered polypropylene to ionizing irradiation at a temperature below 5 DEG C. in the presence of oxygen and copolymerizing the irradiated polypropylene with the vinyl compound. Specified vinyl pyridines are 2 - vinyl, 4-vinyl, 2 methyl-5-vinyl and 2-ethyl-5-vinyl pyridines. The acrylic ester may be methyl acrylate, ethyl acrylate or methyl methacrylate. Other graft monomers are specified. The irradiated polypropylene is immersed in the graft monomer or in a solution thereof in e.g. methanol, ethanol or acetone. In the examples particulate isotactic polypropylene is irradiated with a beam of electrons or Co6- g -rays and grafted with (1) and (9) 2-vinyl pyridine, (2) and (10) methyl acrylate or vinyl acetate, (3) and (11) acrylic acid or vinyl acetate, (4) and (12) acrylic acid or methyl acrylate, (3) 2-methyl-5-vinyl pyridine and ethyl acrylate and (7) 2-vinyl pyridine and ethyl acrylate. The resulting graft polymers are blended with polypropylene and an antioxidant. The compositions may be formed into press sheets which are then dyed or treated with printing ink. |
