| abstract |
The invention relates to a self-crosslinking polyurethane polymer hybrid dispersion based on oxidatively drying polyols with a high degree of film hardness. The inventive dispersion is characterized in that it contains the reaction components: (A) 0.3 to 12 wt. % of an unsaturated fatty acid component which can be oxidatively dried; (B) 1.5 to 18 wt. % of a polyol component comprised of (i) 0.5 to 12 wt. % of a high molecular polyol component, (ii) 0.5 to 3.0 wt. % of a low molecular polyol component, (iii) 0.5 to 3.0 wt. % of a low molecular and anionically modifiable polyol component; (C) 3.5 to 16 wt. % of a polyisocyanate component; (D) 0 to 2 wt. % of a siccative component; (E) 0 to 8 wt. % of a solvent component consisting of (i) at least one organic solvent which is inert with regard to polyisocyanates, and/or of (ii) a reactive diluting agent which is inert with regard to polyisocyanates; (F) 0.3 to 2.5 wt. % of a neutralizing agent component; (G) 0.1 to 1.5 wt. % of a chain lengthening component; (H) 5 to 45 wt. % of a monomer component; (I) 0.05 to 2 wt. % of an initiator component, and water as the remainder. The advantages of the inventive polyurethane polymer hybrid dispersion, such as a high degree of hardness while simultaneously having a high degree of flexibility of the fissure-free films, a good resistance to chemicals, a high degree of stability of the dispersion in a broad pH range, a good freezing/thawing stability, and the use of cost-efficient raw materials, are attained in a simplified synthesis pathway without supplementary chemical crosslinking, and simultaneously with a low content of an organic solvent (</= 4 wt. %) and a good film formation at temperatures of >/= + 10 DEG C. |