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 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 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 and
• R1 represents an organic group which is inert to isocyanate groups at a temperature of 100° C. or less, provided that R1 is not a succinate group, or R1 represents a group corresponding to formula II
• —Y—Si—(X)3 (II)
• 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.