| abstract |
Use of organo-functionally modified polysiloxanes of formula (I) to defoam diesel fuel in an amt. of 0.5-50 ppm is claimed. R1 = 1-4C alkyl or aryl, where at least 80% of R1 = methyl; R2 = 30-90% are R1, and 70-10% are a mixt. of R2a and R2b, where R2a is more polar than R2b; R2a = (a) a phenol deriv. of formula: -R3-(C6H4-z(R4)z)-OH, where R3 = opt. substd. hydrocarbyl, opt. substd. aromatic, or H, alkyl, alkoxy or OH, and z = 0-4; or (b) a residue of formula (II). R5 = H or alkyl; c = 1-20; d = 0-50; e = 0-50; or (c) a residue of formula: -(-CH2)f-OR6, where R6 = H or univalent organic residue, and f = 3-20; or (d) a residue of formula: -(-CH2)g-(-OC2H4)h-(-OC3H6-)i-OR7, where R7 = H or univalent organic residue; and g = 3-6, h = 1-50, i = 0-20 and ratio h:i is more than 5:2. R2b = (e) a residue of formula (III): R8 = H or alkyl; R9 = alkyl, acyl or trialkylsilyl; k = 1-20; m = 0-50; n = 0-50; or (f) a residue of formula: -(-CH2-)o-CH3, where o = 5-30; or (g) a residue of formula: -(-CH2-)g-(-OC2H4-)h-(-OC3H6-)i-OR7, where R7 = H or univalent organic residue, g = 3-6, h = 0-35, i = 1-50 and ratio h:i is less than 5:2; where 10% of R2a = residue (a) and 10% of R2a or R2b are (b), (c), (e) or (f); a = 1-400; and b = 0-10. |