Aq. binders, useful for paints, coating materials and sealants - comprise emulsion of poly:isocyanate in aq. soln. or dispersion of special polyester with carboxylate, hydroxyl and urethane gps.

摘要

Aq. binder combinations (I) contain (A) an aq. soln. of dispersion of a water-thinnable polyol component (II) and (B) a polyisocyanate component with viscosity 50-10,000 mPa.s, consisting of polyisocyanate(s) emulsified in (A), with equiv. ratio NCO:OH = (0.5:1)-(5:1) (II) consists of polyester resin(s) with urethane, carboxylate and OH gps. More specifically, (II) has Mn 3000-100,000 (pref. 6000-50,000), OH number 20-240 (pref. 45-190), acid number 10-45 (pref. 14-33) (with 25-100%, pref. 40-100%, of the COOH gps. in the form of carboxylate) and urethane gp. content 2.5-15.0 (pref. 6.0-12.5) wt.% (w.r.t solid resin), and is present as a 15-65 wt.% aq. soln. with viscosity 10-30,000 mPa.s and pH 5-10; (II) is the reaction prod. of (a) 65-92 (pref. 70-87) wt.% polyester-polyol with OH number 50-500 (pref. 80-350) and acid no. not above 6 (pref. not above 4), (b) 0-7 (pref. 0-3) wt.% diol with mol. wt. 62-240, (c) 2.5-7.5 (pref. 3.0-6.5) wt.% 2,2-bis-(hydroxymethyl)-alkanoic (d) 8-30 (pref. 10-23) wt.% at least difunctional isocyanate(s) with mol. wt. 168-2000 (pref. 166-1500), pref. contg. only (cyclo)aliphatic NCO gps.; (a) is the reaction prod. of (a1) 0-60 (pref. 0-55) wt.% 6-22C (pref. 7-20C) mono-carboxylic acids, (a2) 10-65 (pref. 13-56) wt.% di- and/or tri-carboxylic acids or anhydrides (a3) 15-70 (pref. 25-63) wt.% di- and/or poly-hydric alcohols, (a4) 0-30 (pref. 0) wt.% mono-alcohols and 0-15 (pref. 0) wt.% hydroxycarboxylic acids, lactones, amino-alcohols and/or aminoacids; component (B) consists of polyisocyanate(s) contg. only (cyclo)aliphatic NCO gps. USE/ADVANTAGE - (I) are useful as binders for paints, coating materials and sealants. Water-based, isocyanate-contg. 2-component binders, suitable for use, e.g., in coating mineral constructional materials and road surfaces, wood and timber prods., plastics, etc., are provided.