Two-component polyurethane coating compositions and their use for coating or sealing floors

Claim 1

A two-component polyurethane coating composition which consists essentially of A) a polyisocyanate component containing A1) 50 to 95 wt. % of one or more (cyclo)aliphatic polyisocyanates based on A1.1) 50 to 100 wt. % of one or more polyisocyanates prepared from hexane 1,6-diisocyanate, containing isocyanurate and uretdione groups and having a viscosity at 23° C. of 100 to 300 mPa·s, a content of isocyanate groups of 20 to 24 wt. % and a content of urethane groups of 0 to 5 wt. % and A1.2) 0 to 50 wt. % of one or more polyisocyanates having (cyclo)aliphatically bound isocyanate groups other than the polyisocyanates of A 1.1) and A2) 5 to 50 wt. % of one or more aromatic polyisocyanates based on A2.1) 50 to 100 NCO equivalent % of one or more urethane group-containing polyisocyanates prepared from toluene 2,4-, and optionally 2,6- diisocyanate and having an NCO content of 12 to 20 wt. % and a urethane group content (calculated as CHNO 2 ) of 12 to 29 wt. % and A2.2) 0 to 50 NCO equivalent % of one or more polyisocyanates having aromatically bound isocyanate groups other than the polyisocyanates of A2.1), B) a polyol component containing B1) 50 to 100 wt. % of one or more organic polyhydroxyl compounds having an average hydroxyl content of 6 to 23 wt. % and an average hydroxyl functionality of 2 to 4, selected from (i) polycaprolactone polyols, (ii) polyether polyols wherein the alkylene oxide units are derived from 80 to 100 wt. % of propylene oxide units and 0 to 20 wt. % of ethylene oxide units, or (iii) mixtures of (i) and (ii) and B2) 0 to 50 wt. % of one or more organic polyhydroxyl compounds other than B1) and C) optionally known additives from coating technology, wherein components A) and B) are present in quantities corresponding to an NCO/OH equivalent ratio of 0.9:1 to 1.3:1.