| abstract |
The invention relates to a polyurethane (polymer hybrid) dispersion with reduced hydrophilicity that is produced by reacting a) 50 to 100 parts by weight of a hydrophobically modified block copolymer (A)(i) having two or more hydroxyl groups and a molecular weight of from 500 to 6000 Daltons, and/or 50 to 100 parts by weight of a hydrophobic block copolymer (A)(ii) having two or more hydroxyl groups and a molecular weight of from 500 to 6000 Daltons, and/or 50 to 100 parts by weight of a hydrophobically modified random copolymer (A)(iii) having two or more hydroxyl groups and a molecular weight of from 500 to 6000 Daltons, b) 14 to 140 parts by weight of a polyol component (B), c) 25 to 250 parts by weight of a polyisocyanate component (C), d) 2 to 20 parts by weight of a neutralizing component (D), e) 3 to 30 parts by weight of a chain-extender component (E), and f) 100 to 5000 parts by weight of water, to give a solvent-free or a solvent-poor polyurethane dispersion. Optionally, g) the mixture is further reacted with 117.5 to 3200 parts by weight of a monomer component (F), and h) 0.5 to 50 parts by weight of an initiator component (G), to give a solvent-free or solvent-poor polyurethane polymer hybrid dispersion. The use of hydrophobically modified block copolymers and/or hydrophobically modified random copolymers as the polyols allows the production of polyurethane polymer hybrid dispersions that are characterized by reduced hydrophilicity or water retention, no or little solvent content and high solid content. |