Heat and water resistant aq. acrylic! polymer emulsion adhesive - contg. isocyanate cpd. or polymer, used as pressure-sensitive adhesive

摘要

Heat- and water-resistant adhesive compsn. is based on an aq. acrylic polymer emulsion contg. 0.1-100 wt. % isocyanate cpd. or polymer w.r.t. the solids content. Pref. the adhesive contains 20-60 wt. % acrylic polymer. The isocyanate is dissolved in a solvet (mixt.) which is incompatible with water and compatible with the isocyanate. The compsn. is used as pressure-sensitive adhesive, e.g. for electrical insulation, heat-resistant masks, labels, materials of construction etc. In an example, addn. of 1% of a 75% dioctyl phthalate soln. of methylene bis-diphenyl-isocyanate to a 42% acrylic copolymer emulsion increased the adhesion after 1 (24) hr. ageing under normal conditions from 0.72 (1.01) to 0.89 (1.11) kg./25 mm. and after immersion in water at 60 degrees C. from 0 to .96 kg./25 mm.; and at high temp. (120 degrees C.) from 18 (39) to 120 (120) min./25 mm. x 25 mm.