Silicone - polyether copolymer for use in foam control formulations

A silicone-polyether copolymer comprising unit formula:

• (R13SiO1/2)a(R12SiO2/2)b(R1R2SiO2/2)c, where
• subscripts a, b, and c represent average numbers of each unit in the unit formula and have values such that
• a=2;
• b=20 to 60;
• c=20 to 50;
• each R1 is an independently selected alkyl group of 1 to 12 carbon atoms;
• and
• each R2 is independently selected from the group consisting of H, formula E1′), formula D1′) and formula A1′), where
• formula E1′) is
• where R1 is as described above, subscript m is 0 or 1, and each R6 is a divalent hydrocarbon group;
• formula D1′) is
• where
• each R is independently selected from the group consisting of H, a halogen atom, OH, methyl, and methoxy;
• D′ is a covalent bond, a group of formula —CH2—, or a group of formula —CH2—O—;
• and
• R″ is H or methyl;
• and
• formula A1′) is
• where
• X is H or methyl,
• D has empirical formula —C2H4— or —C3H6—, and
• subscript n is 1, 2, or 3;
• with the proviso that at least one instance of R2 per molecule has formula A1′).