Moisture-curable, polyether urethanes with reactive silane groups and their use as sealants, adhesives and coatings

A moisture-curable, alkoxysilane-functional polyether urethane comprising

• a) 20 to 90% by weight, based on the weight of a) and b), of a polyether urethane containing two or more reactive silane 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 0.007 milliequivalents/g or less, provided that the sum of the number average molecular weights of all of the polyether segments per molecule averages 6000 to 20,000, and wherein the reactive silane groups are incorporated as the reaction product of an isocyanate group with 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,
• R2and R5 are identical or different and represent organic groups which are inert to isocyanate groups at a temperature of 100° C. or less and
• R3 and R4 are identical or different and represent hydrogen or organic groups which are inert towards isocyanate groups at a temperature of 100° C. or less, and
• b) 10 to 80% by weight, based on the weight of a) and b), of a polyether urethane containing one reactive silane group and one or more polyether segments having a number average molecular weight of 1000 to 15,000 and a degree of unsaturation of 0.007 milliequivalents/g or less, wherein the reactive silane groups of component b) are incorporated as the reaction product of an isocyanate group and a compound corresponding to the formula
• wherein X is as defined above and
• R1 represents an alkyl, cycloalkyl or aromatic group having 1 to 12 carbon atoms.