Dow Corning Toray Silicone Company Limited

Junichi Maeshima

Fumitaka Suto

Hidehiko Hosokawa

Tadashi Okawa

Hidetoshi Kondo

Tadashi Hamachi

Takao Takemasa

Norikatsu Higuchi

Process for the production of cyclic siloxane

A method of continuous emulsification that can emulsify high-viscosity organopolysiloxane gums and is capable of continuous mass production. A compounding extruder is used whose barrel 1 contains at least 2 mixing element-equipped shafts 3 installed in parallel. On each shaft elevations and depressions are formed along the axial direction and the elevations and depressions on respective shafts intermesh. Organopolysiloxane gum, emulsifying agent, and water are continuously supplied as starting materials to this compounding extruder, and an organopolysiloxane-in-water emulsion is produced by mixing and homogenizing the starting materials by subjecting them through rotation of the mixing element-equipped shafts to a shearing action at a shear rate of at least 10/second (i.e. 10 reciprocal seconds).

Method for continuously emulsifying organopolysiloxane gums

Method for continuous emulsifying organopolysiloxane gums

A method capable of the continuous mass-production without pressurization and using a low drive force of highly uniform and very storage-stable organopolysiloxane emulsions. The method for the continuous preparation of organopolysiloxane emulsions includes processes (I) and (II). Process (I) is the continuous supply of (a) organopolysiloxane fluid or gum, (b) emulsifying agent, and (c) water to a mixer having a first-stage shearing and stirring mechanism with a stator and a turbine-type rotor having blades that are slanted obliquely from the radial direction when viewed from the axial direction, and a second-stage shearing and stirring mechanism with a stator and a turbine-type rotor having blades that describe spiral curves with respect to the axial direction, and the discharge of an organopolysiloxane-in-water emulsion with an organopolysiloxane content of 10 to 99 weight %. Process (II) is the introduction of dilution water and the emulsion of process (I) into a mixer as described for process (I). A gas can also be injected in process (I).

Method for the continuous preparation of organopolysiloxane emulsions

Method and apparatus for preparing uniform highly dispersed emulsions by using a low drive power and without pressurization, making possible continuous mass production of uniform organopolysiloxane emulsions. An organopolysiloxane, water and a emulsifying agent, are continuously fed across a first-stage shearing and stirring mechanism and a second-stage shearing and stirring mechanism. The first-stage mechanism is a stator and turbine-type rotor whose blades are slanted obliquely from the radial direction when viewed from the axial direction. The second-stage mechanism is a stator and turbine-type rotor whose blades describe spiral curves with respect to the axial direction. The two mechanisms are arranged serially and separated from one another by a relaxation zone. Emulsification is carried out in the first-stage mechanism by an intake and shearing action at a shear rate of at least 100/second, and in the second-stage mechanism by a phase reversal rotating effect and shearing action at a shear rate of at least 100/second.

An organopolysiloxane gum emulsion is afforded by the emulsification of an organopolysiloxane gum in water. The organopolysiloxane gum emulsion is useful as a cosmetic base, lustrant, lubricant, antifoam, fiber-treatment agent, and paint additive. The organopolysiloxane gum emulsion includes

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Chiba Prefecture, Japan

Junichi Maeshima