Aminosilicon-alkylsilicate copolymers

A copolymer comprising (1) at least 1 unit of the formula wherein each Z is H, a monovalent hydrocarbon or amino-hydrocarbon group, R is a divalent hydrocarbon radical of at least 3 C atoms, the Z2N- group is attached to at least the third C removed from the Si atom, R1 is an alkyl group, R2 is a monovalent hydrocarbon radical, a is 0, 1 or 2, b is 0, 1 or 2, and (a+b) is 0, 1 or 2, and (2) at least one unit of the formula wherein R3 is an alkyl group and c is 1, 2 or 3, with or without (3) at least one conventional siloxane unit containing saturated or unsaturated hydrocarbon radicals, may be made by heating a mixture of siloxane (1) and the silicate (2), preferably in the presence of a basic catalyst, e.g. an alkali metal hydroxide or silanolate or a quaternary ammonium hydroxide, and if desired in an inert atmosphere. In a typical example (1) a mixture of an ethoxy-terminated aminopropylsiloxane oil and tetraethyl orthosilicate, with potassium dimethylsilanolate as catalyst, was heated at 155 DEG C. for 16 hours, and finally at 188 DEG C. with Cs(OH) to complete the condensation, to yield an oil; similar preparations are given of and Uses: As polishes for painted steel surfaces, e.g. filing cabinets. Specifications 882,051 and 882,052 are referred to.