| 摘要 |
Compositions comprising polyester or polycarbonate having reacted therein a total of from about 1.0 to about 5,000 parts by weight per million parts by weight of polyester of at least one UV absorbing compound of the formula <IMAGE> wherein R is alkyl or the like, X is carbonyl or sulfonyl, R1 is hydrogen or a substituent, and Y and Z are hydrogen or substituents such as cyano or alkoxycarbonyl, with the provision that at least one of R, R1, Y, and Z is, or forms part of, or contains one or more reactive groups capable of undergoing a condensation reaction under polyester forming conditions, such that the UV absorbing compound is reacted into the polymer. The compound has a maximum light absorbance within the range of from about 320 nm to about 380 nm, which is nonextractable from the polyester and stable under the polyester processing conditions, for imparting UV screening properties to the polymer. Many products such as fruit juices, soft drinks, wines, food products, cosmetics and shampoos are deleteriously affected by UV light when packaged in clear plastic containers which pass significant portions of the available light at any wavelength from approximately 250 to 390 nm. By use of the present compounds polymeric containers can be manufactured which absorb these harmful wavelengths and therefore reduce or eliminate the UV light degradation of products packaged therein. A further advantage of the present polymeric compositions is that conventional polyester dyes and other additives such as pigments, fillers, brighteners and the like may be incorporated therein, and the UV screening properties of the methine compounds impart significant stabilization to both the polyester and the dyes. |
