To obtain a compsn. excellent in weatherability by mixing a thermoplastic polyurethane resin having a hydroxyl group and/or an amino group with a compd. which regenerates an isocyanate under heating, dispersing the mixture in water in the presence of a dispersion stabilizer, and dehydrating and drying the resultant aq. dispersion.
A melt or soln. of a mixture comprising a thermoplastic polyurethane resin having at least one hydroxyl group and/or at least one amino group and 1-30 wt.% compd. which regenerates an isocyanate under heating (e.g. an uretdione-group-contg. polyisocyanate deriv. of the formula) is dispersed in water in the presence of a dispersion stabilizer to give an aq. dispersion, which is dehydrated and dried to give the objective compsn. A maleic acid copolymer salt, a water-soluble cellulose resin, etc., are pref. as the dispersion stabilizer. In the formula, Q is R-OCONH-, or the like; R is a 1-8C alkyl; A is a diisocyanate residue; Z is -NHCOO- or the like; X is a 2-10C dihydric alcohol residue or the like; m is 0-60; and n is 1-60.
MATSUURA KAZUNARI
TAKAI YOSHITSUGU
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