Moisture-curing composition comprising at least two polymers having silane groups

Moisture-curing composition including

• at least one polymer SP1 with end groups of formula (I)
• as well as either
• at least one polymer SP2 with end groups of formula (II)
• and optionally at least one polymer SP3 with end groups of formula (III) not including urea groups or urethane groups;
• or
• at least one polymer SP3 with end groups of formula (III) not including urea groups or urethane groups;
• where
• X1, X1′, X2, and X2′ each independently stand for O, S, or NR5,
• where R5 stands for a hydrogen atom or for a linear or branched hydrocarbon residue with 1 to 20 C atoms, which optionally has cyclic moieties, and which optionally has at least one functional group selected from the group consisting of alkoxysilyl, ether, sulfone, nitrile, nitro, carboxylic acid ester, sulfonic acid ester, and phosphonic acid ester groups.
• R1 and R3 each independently stand for an alkyl group with 1 to 10 C atoms;
• Y1, Y2, and Y3 each independently stand for a hydrolyzable residue;
• a stands for 0 or 1;
• and the dashed lines each represent binding of a group to the polymer;
• with the proviso that:
• either
• the weight ratio of polymer SP1 to polymer SP2 is a value between 0.1 and 0.8,
• or
• the weight ratio of polymer SP1 to polymer SP3 is a value between 0.1 and 0.8,
• and also if polymers SP2 and SP3 are simultaneously present in the composition, the weight ratio of polymer SP2 to polymer SP3 has a value >1.1.