| 摘要 |
Polyester-dispersion (I) containing hydroxy functional- and polyurethane groups, comprises: (a) hydroxy functional polyester (87-95 wt.%) having an average functionality of greater than 2; (b) di-, tri- or monohydroxy carboxylic acid, hydroxysulfonic acid, aminosulfonic acid and/or aminocarbonic acid (1-2.4 wt.%); (c) a difunctional polyisocyanate component (4-10.6 wt.%); and (d) other components (0-3 wt.%), where the dispersion is stabilized by the acid groups containing 50-150% of salt groups. Independent claims are included for: (1) the preparation of (I) comprising: either a single step conversion of the reactants (a-d) at 40-140[deg]C in the presence of organic solvents (5-50 wt.%) and non isocyanate (NCO) reactive neutralization compounds, until the NCO reaches 0%, optional addition of neutralization compounds and/or organic solvents and addition of water to polymer solution or vice versa; or reaction of (b-d) with (a) (exhibiting a NCO:OH(NH) ratio of 1.4:1), in a first step, at 40-140[deg]C in presence of organic solvents (5-50 wt.%) and non-NCO reactive neutralization compounds, to form a NCO functional intermediate product and conversion of the remaining quantity of (a) and optionally further solvents and/or neutralization compounds, until the isocyanate reaches 0%, optional addition of neutralization compounds and/or organic solvents and addition of water to polymer solution or vice versa, in a second step; (2) aqueous binder mixture comprising (I) and cross linker; (3) one component aqueous coating system comprising the polyester dispersion (60-98 wt.%) optionally in combination with others dispersions and a polyisocyanate block (2-40 wt.%) (which can be optionally modified hydrophilically) and an amino cross linker resin; and (4) two component coating system comprising (I) (70-98 wt.%) optionally in combination with other dispersions and hydrophilically modified polyisocyanate having free isocyanates groups of 2-30 wt.%. |
