Process for coating polyolefins

摘要

Coating compositions comprise either (a) the homopolymer of a bicyclic terpene acrylic ester, or of a bicyclic terpene acrylamide or (b) an interpolymer of a monomer from (a) above and one or more other ethylenically unsaturated monomers. The terpene acrylic compound may be derived from a terpene such as camphene, beta-pinene alpha-fenchene, beta-fenchene, iso-bornene and sabinene, and the acrylic ester or amide component may contain an alpha substituent such as lower alkyl, halolower alkyl, hydroxy-lower alkyl and halogen groups. Monomers which can be copolymerized with the terpenic monomers include unsaturated acids and their anhydrides, esters and nitriles, esters of unsaturated alcohols, chloro-alkenes, styrene and its derivatives, dienes and chloro-dienes, vinyl-heterocyclic compounds and vinyl ketones. Many are specified. The weight ratio of terpenic monomer to comonomers is between 20:1 and 1:4. Examples illustrate the polymerization of N-isobornylacrylamide in ethanol using benzoyl peroxide catalyst, and with the same catalyst but in toluene (a) isobornyl acrylate, (b) isobornyl a -chloromethyl-acrylate, (c) isobornyl acrylate and octyl acrylate, (d) isobornyl acrylate and styrene and (e) isobornyl acrylate and vinylidene chloride. For coating, the polymers are dissolved in xylene or toluene. The product of (a) is obtained in the form of a foamed mass, which is ground into finely divided form.ALSO:The surface characteristics of a polyolefin material comprises applying to the surface either (a) the homopolymer of a bicyclic terpene acrylic ester, or of a bicyclic terpene acrylamide or (b) an interpolymer of a monomer from (a) above and one or more other ethylenically unsaturated monomers. The terpene may be camphene, beta-pinene alphafenchene, beta-fenchene, iso-bornene and sabinene. The acrylic compound used to form the terpene monomers may be acrylic acid or may contain an alpha substituent such as lower alkyl, halo-lower alkyl, hydroxy-lower alkyl and halogen groups. Numerous specific compounds are specified. Monomers which can be co-polymerized with the terpene acrylate include vinyl, vinylidene or vinylene monomers. Many are specified. The ratio of terpene acrylate monomer to co-monomers is between 20:1 and 1:4. One or more co-monomers may be used. The application may be by dipping, spraying or spreading with a knife or roller. The coating may be dried at an elevated temperature after application and many commonly used coating systems may be coated over the dried undercoat. Moulded or extruded objects, films, fibres and non-woven fabrics may be so-coated. The top-coat may be of nitro-cellulose lacquers, acrylic lacquers, cellulose acetate-butyrate lacquers, alkyd amine lacquers, phenolic and urea compositions. The polyolefin base may be polyethylene or polypropylene. Printing inks or pigments may be incorporated into the coatings. The polyolefin surface may be treated before coating by corona discharge.