Abstract: An organopolysiloxane emulsion composition comprising:a silicone emulsifying agent comprising a compound represented by the general formula (I): ##STR1## wherein a plurality of R.sup.1 may be the same or different and each represent a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms; R.sup.2 represents a divalent hydrocarbon group having 1 to 6 carbon atoms; R.sup.3 represents an atom or group selected from the group consisting of a hydrogen atom, an acetyl group, R.sup.1, and --Si(R.sup.1).sub.3 ; A represents a divalent hydrocarbon group having 1 to 4 carbon atoms; and x and y are numbers of 5.ltoreq.x.ltoreq.50 and 1.ltoreq.y.ltoreq.100, respectively;an organopolysiloxane which is liquid at room temperature; andwater.This emulsion composition can be prepared as either w/o emulsion or o/w emulsion with good stability.

Abstract: The silicone-based defoaming composition of the invention comprises (a) a polyoxyalkylene group-substituted organopolysiloxane, (b) a dimethyl silicone fluid and (c) a finely divided silica powder. Different from conventional similar compositions, the polyoxyalkylene groups in the component (a) are bonded to the silicon atoms only in the monofunctional siloxy groups and the component (a) necessarily has trifunctional siloxane units. By virtue of this unique formulation, the inventive defoaming composition added to a foaming liquid is very stable against flocculation even at a high temperature and even in the presence of an inorganic salt in a high concentration in the foaming liquid, e.g., dyeing bath.

Abstract: Perfluoroalkyl group containing organopolysiloxanes having a high degree of polymerization can be prepared by reacting a liquid organopolysiloxane of formula (I): R.sup.1.sub.aR.sup.2.sub.b (OH).sub.c SiO.sub.[4.(a+b+c)]/2 with an alkali metal hydroxide to form an alkali metal silanolate; reacting the alkali metal silanolate with a perfluoroalkyl group-containing organosilane of formula (II): RfR.sup.3 SiX.sub.2 to synthesize a perfluoroalkyl group-containing organopolysiloxane intermediate of formula (III): [(R.sup.1.sub.a R.sup.2.sub.b SiO).sub.m (RfR.sup.3 SiO)].sub.n ; and polymerizing the intermediate of formula (III) or a mixture of the intermediate and an organopolysiloxane of formula (IV): R.sup.5.sub.e R.sup.6.sub.g SiO.sub.[(4.(e+g)]/2 in the presence of a strongly acidic catalyst or strongly basic catalyst.

Abstract: An antifoamer which comprises a polyperfluoroether group-containing organopolysiloxane comprising from 20 to 100 mole % of the polyperfluoroether group-containing organopolysiloxane units of a specific type is described. The content of fluorine atoms in the polyperfluoroether group-containing organopolysiloxane is in the range of from 20 to 70 wt % by which foams of organic solvent systems can be inhibited to a substantial extent.