Compositions containing polyether-polysiloxane copolymers

A process for producing polyurethane foam, comprising:

• providing a formulation including one or more organic isocyanates having two or more isocyanate functional groups, one or more polyols having two or more groups that are reactive towards isocyanate, a catalyst and water;
• adding to said formulation a composition comprising compounds of formula (I)
• where
• the indices a are each, independently of one another, from 0 to 500,
• the indices b are each, independently of one another, from 0 to 60,
• the indices c are each, independently of one another, from 0 to 10,
• the indices d are each, independently of one another, from 0 to 10,
• with the proviso that Σc+Σd is greater than or equal to 1 per molecule of formula (I) and that the average number Σd of T units and the average number Σc of Q units per molecule are in each case not greater than 50, the average number Σa of D units per molecule is not greater than 2000 and the average number Σb of siloxy units bearing R4 per molecule is not greater than 100,
• the radicals R are each at least one radical from the group consisting of linear, cyclic or branched, aliphatic or aromatic, saturated or unsaturated hydrocarbon radicals having from 1 to 20 carbon atoms,
• the radicals R5 are each, independently of one another, R4, —OR8 or R,
• the radicals R4 are each, independently of one another, —OR8 or an organic radical which is not R,
• the radicals R7 can each be R, R4, —OR8 and/or a heteroatom-substituted, functional, organic, saturated or unsaturated radical selected from the group consisting of alkyl, chloroalkyl, chloroaryl, fluoroalkyl, cyanoalkyl, acryloxyaryl, acryloxyalkyl, methacryloxyalkyl, methacryloxypropyl and vinyl radicals,
• the radicals R8 are each, independently of one another, hydrogen or an alkyl radical having from 1 to 10 carbon atoms,
• with the proviso that at least one substituent from among R4, R5 and R7 is not R and at least one compound of formula (I) in which at least one of the radicals R4, R5 and R7 is a radical —OR8 is present and, averaged over all compounds of the formula (I) present in the composition, not more than 20 mol % of the radicals R4, R5 and R7 are —OR8;
• and producing a polyurethane foam from said admixture.