Hardenable, liq. epoxide gp.-contg. graft copolymers, (C) are prepd. by a free radical-catalysed copolymerisation process in organic soln. The reaction batch contains (by wt.) (A) 30-80% liq. epoxide cpds. contg. 1 epoxide gp. per molecule, of viscosity 15-14000 cP at 25 degrees C and epoxide equiv. wt. 120-450, dissolved in inert solvents of b. pt. 60-150 degrees C, and (B) 70-20% mixt. consisting (by wt.) of (a) 2-10% 3-5C ethylenically unsatd. acid and/or its anhydride, (b) 60-95 % acrylic acid ester of aliphatic satd. 1-18C monohydric alcohols and (c) 3-35% styrene, vinyl toluene and or alpha-Me-styrene. Reaction batch is kept at 60-150 degrees C until graft copolymerisation is completed. Solvent is opt. distilled off below 130 degrees C under reduced press. (C) are used for preparing hardenable, solvent-free or low-solvent coating- and/or moulding compsns.; as casting resins in electrical industry, esp. for embedding temp.-sensitive switches and electrical parts; as sealing compsns. and, in combination with polyamidoamine hardeners, for prepn. of adhesives. (C) can be stored for several months at 40 degrees C and are miscible with epoxide hardeners. Mixts. of (C) and epoxide hardeners can be used as solvent-free binders, forming solvent, and weather-resistant coatings at room temp. Hardened prods. have high impact strength, resistance to temp. changes and plasticity also at low temps. In an example, graft copolymer is prepd. from a pentaerythritol/epichlorohydrin epoxide, Bu acrylate, styrene and acrylic acid.
展开▼
