Shin-etsu Chemical Co., Ltd.

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Shin-etsu Chemical Col, Ltd.

Masaaki Furuya

Mikio Aramata

Masao Maruyama

Susumu Ueno

Toshio Shinohara

Yukinori Satoh

Yoshihiro Shirota

Hiroshi Nakayama

Makoto Sato

Akihito Tsukuno

Hiroyuki Kobayashi

Akio Muraida

Tetsuo Nakanishi

Tetsuya Inukai

Hajime Ishizaka

Isao Watanuki

Hiromi Nakabayashi

Yasutaka Iwamoto

Masayuki Hasegawa

Akio Ohori

Naoyuki Ida

Shoichi Tanaka

Yoshimitsu Sekiya

Masahito Ikehara

Masaru Suzuki

Kazuo Ogiwara

Yoshihiro Shirata

Kesaji Harada

By reacting two types of organosiloxane compounds in the presence of an alkaline compound and under conditions that do not substantially promote equilibration reaction, a linear organosiloxane polymer having a single peak molecular weight distribution is simply and economically produced with minimized formation of cyclics.

Preparation of linear organosiloxane polymers

When oganohalosilanes are prepared by charging a reactor with a contact mass containing metallic silicon and a copper catalyst, and introducing an organohalide-containing gas feed into the reactor, the partial pressure of organohalide gas in the gas feed is manipulated so as to keep the temperature within the reactor substantially constant. The precise control of reactor internal temperature ensures that organohalosilanes with a higher useful silane content are produced in a safe and inexpensive manner and in high yields from the contact mass having perpetually changing reactivity.

Preparation of organohalosilanes

In the synthesis of organohalosilanes by the direct process of reacting an organic halogen with metallic silicon powder, a metallic copper catalyst in the form of a thermally active metallic copper powder having large strain energy is used.

Metallic copper catalyst and process for making organohalosilanes

Organohalosilanes are prepared by reacting an organic halide with metallic silicon particles in the presence of a metallic copper catalyst which is a metallic copper powder in flake form having a bulk specific gravity of 1-3 g/cm and a mean particle size of 10 &mgr;m to 1 mm as measured by laser diffraction particle size distribution analysis.

Metallic copper catalyst and process for the synthesis of organohalosilanes

A static pressure non-contact type mechanical seal that exhibits and maintains a high sealing function or performance for a prolonged period even when sealing gases containing foreign matter such as oil. A labyrinth seal (,) comprising a plurality of annular grooves (,) and annular plates (,) extending into the grooves is provided, the labyrinth seal partitioning a region C on the outside diameter side of the seal faces (,) in the seal case (,) from the inside region A of a gas treatment machine (,). The seal case is provided with a return passage (,) communicating with the bottom portions of the annular grooves,and opening into the inside region A of the machine. The seal case also includes a purge gas feed passage for supplying purge gas to the region C on the outside diameter side of the seal faces, the purge gas pressure being higher than that in the inside region. A foreign matter recovery passage (,) is also provided in the seal case, the recovery passage opening into the region C on the outside diameter side of the seal faces and communicating with a foreign matter recovery tank (,) maintained under the same pressure as the region C.

Non-contact type mechanical seal

For the continuous hydrolysis of organochlorosilane, a reaction system comprising at least three stages of hydrolysis is used. Each stage includes a reactor and a phase separator wherein hydrolysis is effected to form a hydrolysis mixture which is separated into a hydrolyzate and a hydrogen chloride-containing aqueous medium. The separated aqueous medium is circulated to the reactor. The hydrolyzate is conveyed to the reactor of the subsequent stage. The organochlorosilane is fed into the first stage reactor, the aqueous medium containing an amount of water corresponding to the consumption in one stage is fed into one stage reactor from the subsequent stage, and an amount of water corresponding to the consumption in the overall reaction system is fed in the last stage. Then the entire amount of hydrogen chloride generated in multiple stages of hydrolysis is recovered as anhydrous hydrogen chloride from the first stage. The entire amount of the aqueous media separated in the phase separators is retained in the reaction system.

Continuous hydrolysis of organochlorosilanes

Organohalosilanes are prepared by the Rochow process of reacting metallic silicon particles with an organohalide in the presence of a copper catalyst. The metallic silicon particles, which are prepared by comminuting fragments of metallic silicon raw material, have a mean particle size of 10 &mgr;m to 10 mm and a surface oxygen quantity of up to 0.3 wt % which is given as the difference between the oxygen concentrations determined by in-metal oxygen analysis of the metallic silicon particles and the fragments, respectively.

Process for preparing organohalosilanes

A silane-containing gas is treated by contacting it with a liquid containing silanes or disilanes which are higher boiling than the silanes in the silane-containing gas, thereby easily removing or reducing the amount of silanes in the gas and enabling the recovery of these silanes.

Method for treating silane-containing gas

The direct synthesis of methylchlorosilanes to react metallic silicon with methyl chloride in the presence of a copper catalyst yields a high-boiling fraction of methylchlorodisilanes as by-products. The invention provides a method for preparing monosilanes from the high-boiling fraction by reacting it with hydrogen chloride in the presence of an amine or amide catalyst. The reaction is effected under the condition that the amount of iron, aluminum, zinc, tin and compounds thereof present in the reaction system is less than the equimolar amount with respect to the catalyst. This increases the conversion of disilanes into monosilanes.

Method for preparing monosilanes from a high-boiling fraction formed as

A silanol-terminated diorganopolysiloxane can be reproducibly imparted with a viscosity as desired by the alkali-catalyzed ring-opening or siloxane rearrangement reaction from a cyclic or linear-chain diorganosiloxane oligomer by conducting, instead of exactly controlling the water content in the starting reaction mixture as in the prior art method, the reaction at least in the latter stage thereof under a controlled water-vapor pressure until neutralization of the alkali catalyst after equilibrium of the reaction has been reached according to the discovery that the viscosity or degree of polymerization of the silanol-terminated diorganopolysiloxane is a function of the water-vapor pressure, under which the reaction is brought into equilibrium, at the respective temperature.

Method for the preparation of diorganopolysiloxane end-blocked with

Siloxanes are purified by contacting siloxanes containing ionic crystals as an impurity with a polar solvent, evaporating the solvent, thereby increasing the mean particle size of the ion crystals, and removing the ion crystals from the siloxanes by filtration. The method enables brief, efficient purification of siloxanes in high yields, offering siloxanes having a minimal content of ionic crystals.

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Tokyo, Japan

Masaaki Furuya