Patent ID: 7309753

Claim:
A process for preparing a moisture-curable, polyether urethane containing terminal cyclic urea/reactive silane groups which comprises reacting at an NCO:OH equivalent ratio of 1.5:1 to 2.5:1 a) a hydroxyl component containing i) 20 to 100% 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 6,000 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) 0 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 3,000 to 12,000 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, provided that total percentages of a-ii) and b-ii) add up to at least 10, 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 with c) a compound containing an isocyanate-reactive group and one reactive silane groups in which at least 10 mole % of component c) is a compound corresponding to the formula wherein X represents identical or different organic groups which are inert to isocyanate groups below 100° 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, R 1 and R 2 are identical or different and represent organic groups which are inert to isocyanate groups at a temperature of 100° C. or less and R 3 and R 4 are identical or different and represent hydrogen or organic groups which are inert towards isocyanate groups at a temperature of 100° C. or less, to form an intermediate polyether urethane containing at least a portion of terminal non-cyclic urea/reactive silane groups corresponding to formula II and converting the non-cyclic urea groups to cyclic urea groups by reacting the intermediate polyether urethane in the presence of an acid catalyst and heat to form terminal cyclic urea/reactive silane groups corresponding to formula III and/or formula IV