Crosslinked adhesive film prodn. from polymer emulsion - using water-soluble crosslinking acrylic! polymer contg. prim. hydrazone gps.

摘要

This is a Patent of Addn. to DT 2634956 in which crosslinked films are prepd. by (i) mixing a polymer emulsion, yielding an adhesive film after drying on a substrate, with a water-soluble polyacrylic hydrazide as crosslinking agent, (ii) applying the mixt. to a flexible substrate, e.g. paper or a web, and (iii) crosslinking by quick heating at 60-160(80-120) degrees C. In the present Patent of Addn., the water-soluble polyacrylic hydrazide (I) is replaced, at least partly, by a water-soluble polymer (II) contg. prim. hydrazone gps. The synthesis of (II) is less troublesome than that of (I) and comprises the reaction of carbonyl gp.-contg. polymers in aq. soln., with an equiv. hydrazine hydrate quantity. (II) can be used directly, without further purificn. The Adhesive films have improved resistance to moisture.