| 摘要 |
Normally-solid polyolefins are made resistant to discoloration by ultra-violet light by incorporating therein 0,0005 to 1% by weight of an etherified polhydroxy benzophenone of the structure <FORM:0918464/IV(a)/1> in which R is an alkyl or aryl group containing from 8 to 23 carbon atoms. An anti-oxidant heat stabilizer may also be added. The compositions may be prepared by working the polyolefine and the adjuvants on a rubber mill at a temperature between 140 DEG and 170 DEG C.; or by dissolving the adjuvants in acetone, hexane or benzene, and spraying the solution in a mixer containing the polyolefine. Results of accelerated weathering tests carried out on polyethylene and polypropylene films are given, in which use is made of the following U.V. stabilizers:- the 4-octyl-, -decyl-, -dodecyl-, -hexadecyl-, and -betaphenylethylmono ethers of 2,4-dihydroxy benzophenone, and also 2,21-dihydroxy-4,41-dioctyldecyloxy benzophenone, 2,21-dihydroxy-4-methoxy-41-ethoxy benzophenone, and 2,21-dihydroxy-4-methoxy benzophenone. Among the antioxidants referred to are:- 4,41-thiobis(6-t-butyl-m-cresol), 2,21-methylenebis(4-methyl-6-t-butylphenol) and N-(p-hydroxyphenyl)-morpholine. Specifications 639,306 and 682,420 are referred to. Reference has been directed by the Comptroller to Specification 726,792.ALSO:The invention relates to compositions comprising mono - etherified dihydroxybenzophenones having the general formula <FORM:0918464/IV (b)/1> wherein R is an alkyl or aryl group containing from 8 to 20 carbon atoms. The preparation of 2-hydroxy-4n-octyloxybenzophenone, by refluxing a mixture of 2,4-dihydroxybenzophenone, 1 - bromo - octane, potassium carbonate and acetone, is described. 2-Hydroxy-4n-dodecyloxybenzophenone may be prepared by a similar process. The compounds have use in stabilizing solid polyolefines against ultra-violet light (see Group IV(a)). Specifications 639,306 and 682,420 are referred to. Reference has been directed by the Comptroller to Specification 726,792. |
