Film-forming copolymers and their use in water vapor permeable coatings
AssigneeDow Corning Corporation
InventorsStephen E. Cray, Martin Rowlands
Life of this patent
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Abstract
A film-forming copolymer is formed by copolymerising 100 parts of a curable polyurethane resin and 10 to 100 parts of an organosilicon compound, consisting essentially of SiO.sub.2, R.sub.3 SiO.sub.1/2 and R'R.sub.2 SiO.sub.1/2 units, the ratio of monovalent units to tetravalent units being from 0.4/1 to 2/1 and from 40 to 90% of all monovalent units being R'R.sub.2 SiO.sub.1/2 units. R is a monovalent hydrocarbon group having up to 8 carbons and R' denotes a OH-terminated polyoxyalkylene group. The invention also includes a method of making fabrics waterproof and permeable to water vapour by coating it with such copolymer.
Claims8
A substrate which is coated with a coating composition comprising a copolymer wherein the improvement comprises using as said copolymer a copolymer formed by the copolymerization of 100 parts by weight of a curable polyurethane resin and 10 to 100 parts by weight o an organosilicon compound, consisting essentially of tetravalent SiO.sub.2 units and monovalent R.sub.3 SiO.sub.1/2 and R'R.sub.2 ;
- SiO.sub.1/2 units, wherein the ratio of monovalent units to tetravalent units is from 0.4/1 to 2/1 and from 40 to 90% of all monovalent units present in the organosilicon compound are R'R.sub.2 SiO.sub.1/2 units wherein R denotes a monovalent hydrocarbon group having up to 8 carbon atoms and R' denotes a polyoxyalkylene group which is terminated by a hydroxyl group.
Dependencies are inferred from the claim text.