Method for producing siloxane copolymers

A process for preparing siloxane copolymers, comprising:

• in a first step, reacting an organyloxysilane of the formula
• R7O—SiR12—R6—NHR2 (I)
• with an isocyanate of the formula
• R3(NCO)x (II)
• to form a urea compound of the formula
• R3(NH—(C═O)—NR2—R6—SiR12—OR7)x (III)
• where
• the radicals R1 are individually a monovalent, substituted or unsubstituted hydrocarbon radical optionally interrupted by heteroatom(s),
• R2 individually is hydrogen or a monovalent, substituted or unsubstituted hydrocarbon radical optionally interrupted by heteroatoms,
• R3 individually is a polyvalent, substituted or unsubstituted hydrocarbon radical optionally interrupted by heteroatoms,
• R6 individually is a divalent hydrocarbon radical optionally interrupted by heteroatoms,
• R7 individually is a monovalent, substituted or unsubstituted hydrocarbon radical optionally interrupted by heteroatoms, and
• x is an integer greater than 1;
• optionally, in a second step, hydrolyzing the urea compound of the formula (III) with water;
• and
• in a third step, reacting the urea compound of the formula (III) and/or its reaction product obtained from the second step, with a silanol-terminated compound of the formula
• R5(SiR42—OH)hd y (IV)
• to form a copolymer,
• where
• the radicals R4 individually have one of the meanings given for R1,
• R5 individually are polyvalent polyether radicals, polyester radicals, or polysiloxane radicals, and
• y is an integer greater than 1.