Method for producing alkyl silicone resins

A process for producing alkyl silicone resins (A) containing at least 80 wt % of units of the general formula (I)

• where
• R1 may be identical or different and is a monovalent, SiC-bonded, unsubstituted or substituted aliphatic hydrocarbon radical having not more than 4 carbon atoms,
• R2 may be identical or different and is hydrogen or a monovalent, unsubstituted or substituted hydrocarbon radical having not more than 4 carbon atoms,
• R3 may be identical or different and is a monovalent, SiC-bonded, unsubstituted or substituted hydrocarbon radical having at least 5 carbon atoms,
• a is 0, 1, 2 or 3,
• b is 0, 1, 2 or 3 and
• c is 0, 1 or 2, with the proviso that the sum of a+b+c is less than or equal to 3 and in at least 50% of the units of the general formula (I) the sum of a+b is 0 or 1 and in at least 40% of the units of the general formula (I) c is 1,
• d is 0 or 1, and
• where the amount of alkoxy groups R2O is 3-20 wt %,
• where alkylalkoxysilane (A1) of the general formula (II)
• where R1, R2, R3, a and c have the definitions stated above,
• is mixed in a first reaction step (R1) with one of the following:
• a pure acid (S) having pKa of not more than 5, an at least 5 wt % aqueous solution of an acid (S) having a pKa of not more than 5 or a halosilane compound (A2) of the general formula (III)
• where X is a halogen atom and R1, R3, a and c have the definitions stated above,
• and subsequently in at least one further reaction step (R2) water is added,
• wherein the mixing in the first reaction step (R1) results in a clear, single-phase reaction mixture, and wherein the reaction mixture remains clear during the addition of water in the reaction step (R2).