| 摘要 |
Described is a polyurethane/polymer hybrid dispersion with high film hardness, which comprises the reaction components(A) from 3 to 25% by weight of a polyol component consisting of(i) from 2 to 20% by weight of a relatively high molecular mass polyol component,(ii) from 0.5 to 5% by weight of a low molecular mass polyol component,(iii) from 0.5 to 3% by weight of a low molecular mass and anionically modifiable polyol component,(B) from 2 to 20% by weight of a polyisocyanate component,(C) if desired, from 0 to 6% by weight of a solvent component consisting of(i) at least one polyisocyanate-inert organic solvent and/or(ii) a polyisocyanate-inert reactive diluent,(D) from 0.15 to 1.5% by weight of a neutralizing component,(E) from 0.1 to 1% by weight of a chain extender component,(F) from 5 to 40% by weight of a monomer component,(G) from 0.01 to 1.5% by weight of an initiator component,and water as the remainder.The advantages of the polyurethane/polymer hybrid dispersion of the invention, such as high hardness coupled with high flexibility of the crack-free films, good chemical resistance, great stability of the dispersion within a wide pH range, good freeze/thaw stability, and the use of inexpensive raw materials, are achieved in a simplified synthesis route, without subsequence chemical crosslinking, with a simultaneously low organic solvent content (<=4% by weight), and with good filming at temperatures <=+10° C.
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