Binding agent for coating compositions for automobiles comprises binding agents dispersed in water, water soluble or dispersible polyhydroxyl compounds and blocked polyisocyanates and/or amino resins

摘要

A binding agent mixture for aqueous stoved coating compositions comprises (A) binding agents dispersed in water based on polyacrylate polyols and/or polyester-polyacrylatepolyols and at least one partially blocked polyisocyanate component (B) water soluble or dispersible polyhydroxyl compounds (C) water soluble or dispersible blocked polyisocyanates and/or amino resins. A binding agent mixture (I) for aqueous stoved coating compositions (II) comprises (A) binding agents dispersed in water (B) water soluble or dispersible polyhydroxyl compounds (C) water soluble or dispersible blocked polyisocyanates and/or amino resins (D) optionally other water soluble or dispersible substances whereby (A) comprises (A1) at least one polyolcomponent based on polyacrylate polyols and/or polyester-polyacrylatepolyols having a hydroxyl group content of 1.0-8.0 wt.%, a carboxyl group content of 0-3.0 wt.%, a wt. av. mol. wt of 2000-50,000 and glass transition temperature of at least 10 deg C, (A2) at least one polyisocyanate component having 5.0-25 wt.% blocked isocyanate groups based on (cyclo)aliphatic polyisocyanates (A3) optionally other polyfunctional polyols (A4) optionally other cross-linking substances (A5) optionally external emulsifiers and (A6) optionally conventional additives such that component (A) has a dispersed particle size of 0.05-10(0.1-5), preferably 0.2-1.5 mu m following preparation by a direct dispersion process or phase transfer process using a high efficiency dispersion apparatus An Independent claim is included for aqueous stoved coating compositions (II) that contains the binding agent (I).