| 摘要 |
An antifoam formulations comprise (A) antifoam agent based on siloxanes and (B) branched polyether/polysiloxane copolymers comprising structural units of the formula <?in-line-formulae description="In-line Formulae" end="lead"?>Y[-C<SUB>n</SUB>H<SUB>2n</SUB>-(R<SUB>2</SUB>SiO)<SUB>m</SUB>-A<SUB>p</SUB>-R<SUB>2</SUB>Si-G]<SUB>x</SUB> (I)<?in-line-formulae description="In-line Formulae" end="tail"?> in which Y is a multivalent, optionally heteroatom-containing hydrocarbon radical, R are monovalent optionally halogenated hydrocarbon radicals, A is a radical -R<SUB>2</SUB>Si-R<SUP>2</SUP>-(R<SUB>2</SUB>SiO)m-, G is a monovalent radical -C<SUB>f</SUB>H<SUB>2f-2k</SUB>-Z or a divalent radical -C<SUB>n</SUB>H<SUB>2n</SUB>- bonded to a radical Y, Z <?in-line-formulae description="In-line Formulae" end="lead"?>-(R<SUP>6</SUP>)<SUB>v</SUB>-(OCH<SUB>2</SUB>CH<SUB>2</SUB>)<SUB>a</SUB>[OCH<SUB>2</SUB>CH(CH<SUB>3</SUB>)]<SUB>b</SUB>[OCH<SUB>2</SUB>CH(CH<SUB>2</SUB>CH<SUB>3</SUB>)]<SUB>c</SUB>-OR<SUP>3</SUP>,<?in-line-formulae description="In-line Formulae" end="tail"?> in which R<SUP>3 </SUP>is hydrogen, a hydrocarbon radical, or a radical R-C(O)-, R<SUP>6 </SUP>is a divalent hydrocarbon radical, v is 0 or 1, a, b and c are 0 or an integer between 1 and 1000, the sum (a+b+c) being from 2 to 2000, x is 3 to 10, f is 2 to 12, k is 0 or 1, n is 2 to 12, m is at least 1, and p is 0 or a positive integer, the branched polyether/polysiloxane copolymers (B) containing on average at least one group Z.
|
