Patent ID: 6809170
Filing Date: 2004-10-26
Classification: C08G

Abstract:
A process for preparing a moisture-curable, alkoxysilane-functional polyether urethane by reacting at an NCO:OH equivalent ratio of 1.5:1 to 2.5:1a) a hydroxyl component containing i) 20 to 60% by weight, based on the weight of component a), of a polyether containing two hydroxyl groups and one or more polyether segments, wherein the polyether segments have a number average molecular weight of at least 3000 and a degree of unsaturation of less than 0.04 milliequivalents/g, provided that the sum of the number average molecular weights of all of the polyether segments per molecule averages 6000 to 20,000, and ii) 40 to 80% by weight, based on the weight of component a), of a polyether containing one hydroxyl group and one or more polyether segments having a number average molecular weight of 1000 to 15,000, with b) an isocyanate component containing i) 20 to 100% by weight, based on the weight of component b), of a compound containing two isocyanate groups, and ii) 0 to 80% by weight, based on the weight of component b), of a compound containing one isocyanate group, to form an isocyanate-containing reaction product and subsequently reacting this reaction product at an equivalent ratio of isocyanate groups to isocyanate-reactive groups of 0.8:1 to 1.1:1 withc) compounds containing an isocyanate-reactive group and one or more reactive silane groups selected from i) compounds corresponding to formula I â€ƒwherein X represents identical or different organic groups which are inert to isocyanate groups below 100Â° C., provided that at least two of these groups are alkoxy or acyloxy groups, Y represents a linear or branched alkylene group containing 1 to 8 carbon atoms and R1 represents an organic group selected from alkyl, cycloalkyl or aromatic groups having from 1 to 12 carbon atoms and a group corresponding to formula II â€”Yâ€”Siâ€”(X)3,â€ƒâ€ƒ(II) â€ƒand ii) the reaction product of aminosilanes corresponding to formula IV H2Nâ€”Yâ€”Siâ€”(X)3â€ƒâ€ƒ(IV) â€ƒwith maleic or fumaric acid esters corresponding to formula V R5OOCâ€”CR3&boxH;CR4â€”COOR2â€ƒâ€ƒ(V) wherein X and Y are as defined above, R2 and R5 are identical or different and represent alkyl groups having 1 to 4 carbon atoms, and R3 and R4 are identical or different and represent hydrogen or organic groups which are inert towards isocyanate groups at a temperature of 100Â° C. or less, to form a moisture-curable, alkoxysilane-functional polyether urethane.