Abstract: Compositions of a mold release agent for casting are disclosed which are excellent in heat resistance and releasing effect, and contain an organopolysiloxane expressed by the following general formula (1) ##STR1## wherein R represents methyl group or phenyl group, R.sup.1 represents an alkyl group, aralkyl group, or aryl group, R.sup.2 represents R or R.sup.1, x is an integer of from 0 to 1000, y is an integer of from 10 to 1000, and x+y is an integer of from 10 to 2000.

Abstract: A surface treating agent for coating vehicles comprises an amino group-containing polyorganosiloxane represented by the general formula (1) below, an organic acid, polydimethylsiloxane having a viscosity at 25.degree. C. of 5 to 300 cSt and an aqueous medium: ##STR1## wherein R is a monovalent hydrocarbyl group having a carbon number of 1 to 20, R.sup.1 is any of a monovalent hydrocarbyl group having a carbon number of 1 to 20, an alkoxy group having a carbon number of 1 to 6 or hydroxyl group, m is an integer of 10 to 1,000, n is an integer of 1 to 20, R each may be identical with or different from the other, and R.sup.1 each may also be identical with or different from the other, R.sup.2 is a substituent represented by the general formula (2) of: ##STR2## wherein R.sup.3 and R.sup.5 are a divalent hydrocarbyl group having a carbon number of 1 to 6, R.sup.4, R.sup.6 and R.sup.7 are hydrogen atom or a monovalent hydrocarbyl group having a carbon number of 1 to 20, r is an integer of 0 to 3, R.sup.3 and R.sup.

Abstract: The water repellent for window panes of automobiles of this invention comprises an amino group-containing polyorganosiloxane having the specific structure, an organic acid, a surfactant and an aqueous solvent, which is usable regardless of whether it is fine or rains, and can provide a uniform film having a good water repellency held for a long period.