| 摘要 |
The resistance to light of articles having a basis of chlorine-containing vinyl polymers or copolymers is improved by uniformly incorporating in them 0.1 to 10 parts per thousand by weight of compounds of hexavalent chromium. The process may be carried out by intimately mixing the chromium compound with the polymer before forming the article or incorporating it during manufacture of the article or by treatment of the finished article, e.g. by dipping or spraying. The treated articles, if desired, may be subjected to treatment with additional agents, e.g. pigments, or natural or synthetic polymers or their derivatives. The process may be applied to the treatment of films, threads, fibres, artificial horsehair, strips, rods, ribbons, fabrics, filaments, varnishes and foils, having a basis of the polymer. In examples (1) a mixture of polyvinyl chloride, sodium bichromate, acetone and carbon disulphide is spun; (2) a film is cast from a solution containing polyvinyl chloride, lithium bichromate, acetone and carbon disulphide, and (3) a fabric formed of a copolymer of 85 per cent vinyl chloride and 15 per cent vinyl acetate is soaked in an aqueous acetone solution of potassium bichromate. |
