| 摘要 |
A composition having good resistance to light comprises an organic polymer subject to deterioration on exposure to light and containing carbon and hydrocarbon with any additional element being chlorine, oxygen or sulphur and, as a stabiliser therefor and in intimate mixture therewith, a second polymer of molecular weight at least 10,000 and containing salicylate units of the formula : <FORM:0848354/IV(a)/1> where n is 0 or 1, said second polymer being present in amount such that at least 0,5% by weight of the composition is salicylate units. Polymers which can be stabilised include polyvinyl halides, polyvinylidene chloride, polychlorobutadienes, chlorinated polyethylene and chlorinated rubber, sulphochlorinated hydrocarbon polymers, polymerised vinyl esters, polyesters, regenerated cellulose, cellulose esters and ethers, polymerised vinyl hydrocarbons, and polymerised or methacrylic acids or esters. The salicylate unit containing polymers can be homopolymers of vinyl or allyl salicylate, but are preferably copolymers, suitably with acrylic esters of alcohols of 1 to 4 carbon atoms, vinyl esters of aliphatic acids, or vinylidene hydrocarbons of 2 to 4 carbon atoms. The salicylate groups in the polymers can be present in the form of chelates with, for example, aluminium, zirconium, zinc, magnesium, beryllium, copper, manganese, iron, cobalt and nickel. They can be produced by transchelation, using the process of U.S.A. Specification 535,520, by treating the polymer with a chelate of a polyvalent metal with a volatile chelating agent, e.g. 1,3-diketones, b -ketoesters or aromatic a -hydroxy aldehydes and esters. Additional solvent, such as aromatic hydrocarbons, di-n-butyl ether, tetrahydrofuran, methyl isobutyl ketone, cyclohexanone and chloroform is desirably employed. Chelation can be carried out at the same time as the blending of the salicylate polymer with the light-sensitive polymer. Examples show the application of the invention to a copolymer of vinyl chloride and p vinyl acetate, to a chlorinated ethylene polymer also containing sulphonyl chloride groups and to polyethylene. The blends of the polymers can be produced by mixing, milling on hot or cold rolls, of by solution of dispersion mixing. The light-sensitive polymer and the salicylate monomer can be polymerised and bonded together by treatment with high energy radiation, such as that from a Van de Graaff accelerator. Specification 807,198 also is referred to.
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