GRAFT COPOLYMER PRESSURE-SENSITIVE ADHESIVES, THEIR MANUFACTURE AND USE

摘要

The invention relates to pressure-sensitive adhesive which contain preferably from 60% to 85% by weight of graft copolymers for use as polymeric pressure-sensitive adhesives, and from 15% to 40% by weight of plasticizers such as phthalate or phosphate plasticizers. The graft copolymer for use as polymeric pressure-sensitive adhesive consists of from 5% to 30% by weight of a graft base and from 70% to 95% by weight of grafted-on monomer units. The graft base is a copolymer with from 40% to 85% by weight of ethylene units and from 15% to 60% by weight of vinyl acetate units and optionally up to 10% by weight of monomer units of other unsaturated compounds. It may be replaced wholly or partially by other graft bases. The grafted-on monomer units consists of from 30% to 80% by weight of units of vinyl esters of short-chained carboxylic acids, especially vinyl acetate, from 20% to 70% by weight of units of vinyl esters of relatively long-chained carboxylic acids, for example vinyl laurate, and/or units of esters of .alpha.,.beta.-unsaturated carboxylic acids with relatively long-chained alcohols and/or units of esters of dicarboxylic acids with relatively long-chained alcohols, from 0.5% to 15% by weight of N-vinyl-2-pyrrolidone units and from 0 to 20% by weight of other olefinically-unsaturated copolymerizable monomer units. These graft copolymers are manufactured by free-radical-initiated grafting of a solution of the copolymers in a monomer mixture. The pressure-sensitive adhesives according to the invention can be used in particular as hot melt pressure-sensitive adhesives.