| 摘要 |
<p>New liq. coating compsns. comprise a soln. of polystyrene in one or more organic solvents, a plasticiser for the polystyrene and a substance which permits or retards the degradation of the polymer by ultraviolet radiation. Pref. a preparatory coat is just applied to make the surface smooth. The coating is pref. of poly(vinyl butyral) if the surface is non-porous and non-metallic, or a mordant or cleaning layer for non-ferrous metals. Other metallic surfaces may be jet-sanded to roughen the surface. The compsns. are used for paints, transparent varnishes, insulators for application to metallic surfaces or surfaces coated with cement, brick or stone; and as insulators for the under-parts of motor vehicles. The compsns. form hard, durable coatings that are not readily scratched and which are resistant to all chemicals except alkalis and very concd. acids. The coatings are not readily corroded by battery acids. They resist decolorising agents and therefore can be sterilised or cleaned with a bleaching agent without blisters being formed. The surfaces are very smooth and cannot be written on. Because they make use of waste polystyrene, they are not very costly.</p> |
