초록 ▼

This invention relates to coating compositions containing (A) a polyurethane system containing either a polyurethane containing ionic groups and polyethylene oxide units or a precursor thereof prepared from a blocked isocyanate prepolymer and a cross-linking agent and, optionally, (B) organic solven

This invention relates to coating compositions containing (A) a polyurethane system containing either a polyurethane containing ionic groups and polyethylene oxide units or a precursor thereof prepared from a blocked isocyanate prepolymer and a cross-linking agent and, optionally, (B) organic solvents. This invention further relates to the use of such coating compositions to prepare coatings that are permeable to water vapor.

대표청구항 ▼

A coating composition for the preparation of water-vapor permeable coatings comprising (A) a polyurethane system containing either (a) a polyurethane having an elongation at break (according to DIN 53,504) of from 200 to 1000% and containing ionic groups in a quantity of from 0.5 to 40 milliequivale

A coating composition for the preparation of water-vapor permeable coatings comprising (A) a polyurethane system containing either (a) a polyurethane having an elongation at break (according to DIN 53,504) of from 200 to 1000% and containing ionic groups in a quantity of from 0.5 to 40 milliequivalents per 100 g of polyurethane (a) and from 10 to 45% by weight, based on polyurethane (a), of polyethylene oxide units －(CH2CH2O)n－in which the sequence length n is from 3 to 55, prepared from (1) one or more polyisocyanates, (2) one or more hydroxyl-terminated polyethers having number average molecular weights of from 350 to 5000 selected from the group consisting of (i) a homopolyethylene glycol or an ethylene oxide/propylene oxide copolymer containing 2 or 3 hydroxyl end groups and having polyethylene oxide units distributed in blocks or at random, (ii) a polycarbonate or polyether ester based on said homopolyethylene glycol or ethylene oxide/propylene oxide copolymer, and (iii) mixtures thereof, (3) an ionic-group-containing diol and/or diamine, and (4) one or more chain lengthening agents having molecular weights of from 32 to 349, wherein said polyurethane (a) is prepared by the one-shot reaction of components (1), (2), (3), and (4) or by reaction of components (1), (2), and (3) to form a prepolymer that is then reacted with component (4), or (b) a precursor that is reactive at elevated temperatures of about 70°to about 100°C. and capable of forming said polyurethane (a) prepared from (i) a blocked isocyanate prepolymer corresponding to said polyurethane (a), and (ii) a cross-linking agent; and (B) optionally, one or more organic solvents in a quantity of up to 80% by weight, based on the sum of components (A) and (B), wherein said coating composition contains less than 5% by weight of water, based on the sum of components (A) and (B).