PURPOSE: A molded product of vinyl chloride resin containing an antioxidant is irradiated with ultraviolet rays of wave length rather than a specific zone to form the crosslinked layer of the antioxidant on the surface, thus preventing the migration of plasticizers and additive and increasing weathering resistance.
CONSTITUTION: To 100pts.wt. of a vinyl chloride resin, are added more than 0.05, preferably 0.1W5pts. of an antioxidant such as phnolic, amine or sulfuric agent to prepare a vinyl chloride resin composition. Then, the composition is molded and irradiated with ultraviolet rays of less than 200nm wave length, preferably low- pressure mercury lamp with emission spectra on 185, 254, 313 and 365nm to form a high-density crosslinked layer near the surface of the molded product.
EFFECT: This treatment prevents the deterioration of the inner part of the polymer and sharply increases the resistance to deterioration caused by ultraviolet rays.
SUDA MASAO
IMADA KIYOSHI
UENO SUSUMU
NOMURA HIROKAZU
SHINETSU CHEM IND CO
| JPS5464573A | 1979-05-24 |