| 摘要 |
<p>Films or tubes of polyethylene or copolymers of ethylene with isobutylene, vinyl acetate, styrene or vinyl chloride are extruded into an atmosphere containing at least 0.05 per cent ozone, the film or tube being maintained at a temperature of at least 150 DEG C. A film may be formed by extruding a molten polymer through a slot orifice or by milling a molten polymer on closely spaced calender rolls. The atmosphere of ozone may be maintained between the point of extrusion and the quench bath and during its passage through this atmosphere the film may be subjected to ultra-violet light. The molten polymer may be at a temperature of 150 DEG to 325 DEG C. and the quench bath at a temperature of 25 DEG to 95 DEG C. The quench bath may contain one or a mixture of chlorine, bromine, iodine, fluorine, hydrochloric acid, hydrobromic acid, hydroiodic acid, hydrofluoric acid, hydrogen peroxide, nitrous acid, alkaline hypochlorites, concentrated nitric acid or mixtures of concentrated nitric and sulphuric acids. After quenching, the film may be neutralized with aqueous sodium hydroxide. The process of the invention improves the receptivity of the film or tube for aniline and rotogravure printing inks and for coatings of synthetic resins or cellulose derivatives. Specifications 557,544, [Group IV], 681,517, [Group VIII], and 755,738 and U.S.A. Specification 2,430,860 are referred to.</p> |
