| 摘要 |
Provided is a method for producing an organopolysiloxane emulsion composition which contains an organopolysiloxane having a trialkyl group at a terminal thereof and having a viscosity of 50,000 mm2/s or more at 25° C., within a shorter time compared with the conventional methods. A method for producing an emulsion composition which contains an organopolysiloxane having a viscosity of 50,000 mm2/s or more at 25° C. and capped with a trialkylsilyl group, said method comprising: (I) emulsifying a mixture comprising (A) an organopolysiloxane, (B) a nonionic surfactant, (C) an anionic surfactant, (D-1) an acidic compound and (E-1) water to prepare an emulsion composition; (II) adding (D-2) an acidic compound and (E-2) water to the emulsion composition to perform emulsion polymerization; and (III) adding 0.001 part by mass or more of (F) a compound to the resultant product to perform emulsion polymerization again. |
| 主权项 |
1. A method for preparing an emulsion composition containing an organopolysiloxane that is capped with a trialkylsilyl group and has a viscosity at 25° C. of at least 50,000 mm2/s, the method comprising the steps of, in order:
(I) preparing an emulsion composition by emulsifying a mixture containing:
(A) 100 parts by weight of an organopolysiloxane of general formula (1) below having an octamethylcyclotetrasiloxane content of not more than 1,000 ppm
HO(R12SiO)nH (1)(wherein each R1 is independently a hydrogen atom or a substituted or unsubstituted hydrocarbon group of 1 to 20 carbon atoms, and n is a number such that the organopolysiloxane has a viscosity at 25° C. of from 25 to 20,000 mm2/s),
(B) 0 to 100 parts by weight of a nonionic surfactant,(C) 0 to 100 parts by weight of an anionic surfactant,(D-1) 0 to 100 parts by weight of an acidic compound (with the proviso that the combined amount of (B), (C) and (D-1) is at least 0.1 part by weight), and(E-1) 1 to 10,000 parts by weight of water; (II) adding to the resulting emulsion composition:
(D-2) 0 to 25 parts by weight of an acidic compound (with the proviso that the combined amount of (D-1) and (D-2) is at least 0.1 part by weight), and(E-2) 0 to 10,000 parts by weight of water, and subsequently carrying out emulsion polymerization at a temperature below 40° C. until the viscosity at 25° C. of the organopolysiloxane becomes at least 50,000 mm2/s; and (III) adding at least 0.001 part by weight of:
(F) a compound of general formula (2) or (3) below
R23SiOH (2)R23SiO(R32SiO)mSiR23 (3)(wherein each R2 is independently an alkyl group of 1 to 18 carbon atoms which may be interrupted by an oxygen atom, each R3 is independently a hydrogen atom or a substituted or unsubstituted hydrocarbon group of 1 to 20 carbon atoms, and m is a number such that the viscosity at 25° C. of the organopolysiloxane is from 0.65 to 100 mm2/s) and again carrying out emulsion polymerization. |
