Shin-etsu Chemical Co., Ltd.

Rhodia Chimie

Bridgestone Corporation

Minoru Igarashi

Masaharu Takahashi

Yutaka Hagiwara

Yoshio Inoue

Tsutomu Nakamura

Susumu Sekiguchi

Keiji Shibata

Atsushi Yaginuma

Atsuo Ito

Tomoyoshi Furihata

Naoki Omura

Hiroto Ohwada

Kenji Tawara

Yoshio Tomizawa

Tsuneo Kimura

Masayuki Ikeno

Naoki Yamakawa

Yoshiaki Koike

Agnès Pottier

Daichi Todoroki

Junichi Tsukada

Masayuki Yoshida

Yuka Mayumi

Kyu-Min Hwang

Hyung-Bae Kim

Nahohiko Harada

A transparent desiccant for organic EL and methods for using the transparent desiccant are described, which is a cured product of an organopolysiloxane composition that contains (A) an alkenyl-group-containing organopolysiloxane including a linear organopolysiloxane having at least two alkenyl groups per molecule, (B) chemical formula (I):HRSiO&#x2003;&#x2003;(I)(where R is a C1-10 monovalent hydrocarbon group, a is 0.001-1.0, and b is 0.7-2.1), and (C) a hydrosilylation catalyst. The number of mol Y of silicon-atom-bonded hydrogen atoms (mol) in component (B) satisfies the formula 0.002 (mol)&#x2264;(Y-X)&#x2264;0.8 (mol) relative to the number of mol X of silicon-atom-bonded alkenyl groups (mol) in component (A). The transparent desiccant for an organic EL is highly transparent, capable of top emission, has low shrinkage growth, suppresses loss of an element light-emitting portion, suppresses the short-circuit phenomenon, and has exceptional defoaming properties in the material curing process.

Transparent desiccant for organic EL, and method for using same

Provided is a silicone rubber composition suited for use as a key pad having excellent dynamic fatigue durability (keying durability) and a silicone rubber key pad obtained by curing molding of the composition. A silicone rubber composition for making a key pad includes:

Silicone rubber composition for making key pad and key pad

A solar cell module is manufactured by encapsulating a solar cell matrix comprising a plurality of electrically connected solar cell components between a transparent panel and a backsheet with a resin. The method involves (i) embossing opposite surfaces of a green silicone rubber sheet, (ii) arranging a transparent panel (), silicone rubber sheet (), solar cell matrix (), silicone rubber sheet (), and backsheet () to form a multilayer assembly, and (iii) heating and compressing the assembly for vacuum lamination for establishing a seal around the solar cell matrix.

Manufacture of solar cell module

A UV curable silicone rubber composition is provided. The composition does not undergo curing failure, foaming, and other undesirable conditions even if a water-containing inorganic filler such as zeolite were added. A UV curable silicone rubber composition comprising (A) 100 parts by weight of an organopolysiloxane having at least 2 alkenyl groups per molecule represented by the average compositional formula (I): RSiO(I) (wherein Ris independently a substituted or unsubstituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05); (B) 1 to 300 parts by weight of an inorganic filler having a water content of at least 0.5% by weight; (C) 0.1 to 50 parts by weight of an organohydrogenpolysiloxane having at least 2 silicon-bonded hydrogen atoms per molecule; and (D) a catalytic amount of a photoactive platinum complex curing catalyst.

Silicone rubber composition, silicone rubber molded article, and production method thereof

The invention relates to the use of a precipitated silica, pretreated by at least one organosilane hydrophobic compound or one hydrophobic silicone oil, as a reinforcing filler for silicone elastomer, the pretreated silica being incorporated in the silicone elastomer by cold mixing and having the following features: &#x2014;a BET specific surface ranging from 50 to 450 m/g, &#x2014;a water wettability lower than 80, &#x2014;a sulfur content lower than 0.1% by weight. The invention is directed to the curable silicone elastomer composition thus obtained.

Use of a pretreated precipitated silica as a reinforcing filler for silicon elastomer and the curable silicone elastomer compositions thus obtained by cold mixing

A method for producing a silicone rubber compound in a reduced blending time, and which imparts excellent resistance to plasticity reversion and the cured silicone rubber prepared without heat treatment has excellent resistance to compression set. (A) an organopolysiloxane with polymerization degree of at least 100 represented by the following average compositional formula (I):RSiO&#x2003;&#x2003;(I)(R: a substituted or unsubstituted monovalent hydrocarbon group, a: 1.95 to 2.05), (B) a reinforcing silica having a specific surface area (BET) of at least 50 m/g, and (C) a preliminary hydrolysis product of (C-1) an alkoxysilane represented by the following formula (II):RSi(OR)&#x2003;&#x2003;(II)(R: hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R: a substituted or unsubstituted alkyl group, m: 0, 1, 2, or 3), and (C-2) water at a molar amount 0.3 to 5 times the alkoxy group in the alkoxysilane of component (C-1) are mixed and heated.

Method for producing silicone rubber compound and silicone rubber composition

Disclosed is a millable type silicone rubber composition including as an essential components:

Silicone rubber composition for optical sheet, and optical sheet

A conductive silicone rubber composition is provided, which includes (a) 100 parts by weight of an organopolysiloxane represented by an average composition formula of R SiO wherein R is an unsubstituted or substituted monovalent hydrocarbon group which may be the same or different, and a is a positive number of 1.90 to 2.05, (b) 50 to 500 parts by weight of conductive particles comprising carbon coated with Ni, and (c) 0.1 to 10 parts by weight of an organic peroxide. This composition has an adequate pot life, is unlikely to be affected by catalyst poisoning, and is suitable for normal pressure hot air vulcanization. Cured products produced from the composition has a low volume resistivity and excellent electromagnetic interference sealing properties.

Conductive silicone rubber composition

A silicone rubber composition comprising an organopolysiloxane containing at least two alkenyl radicals and having a degree of polymerization of at least 100, an organopolysiloxane or organosilane, reinforcing silica, and an alkali metal salt of phosphoric acid has minimized plasticity recovery with time and improved storage stability and cures with an organic peroxide or addition reaction curing agent into a silicone rubber having improved compression set and yellowing resistance.

Silicone rubber compositions

Silanol group-containing organosilicon compounds having a low average degree of polymerization are prepared in an efficient and inexpensive manner by adding water at pH 1-5 to an organooxysilane, mixing them, thus forming a hydrolyzed organooxysilane mixture, and adding a mono- and/or di-alkali metal salt of phosphoric acid to the mixture so as to give pH 5-9.

Preparation of silanol-containing organosilicon compounds

An organopolysiloxane gum is prepared by polymerizing a cyclic organopolysiloxane with a low molecular weight linear organopolysiloxane end-blocked with a triorganosilyl group in the presence of a thermally decomposable catalyst. After the polymerization reaction, the catalyst is deactivated by heating the reaction product under a subatmospheric pressure of typically up to 500 mmHg.

Preparation of organopolysiloxane gum

An organopolysiloxane gum is continuously prepared by (I) mixing at least one cyclopolysiloxane with an end capping agent, (II) feeding the mixture to a self-cleaning reactor along with a polymerization catalyst of thermal decomposition type, and effecting polymerization at a temperature of 80-130&deg; C., (III) heating the reaction mixture of step (II) at a temperature of 130-200&deg; C. under subatmospheric pressure for deactivating the catalyst, thereby terminating the polymerization reaction, and (IV) continuously removing the cyclopolysiloxane and volatile components from the reaction product.

In a first step, basic components including (A) 100 parts by weight of an organopolysiloxane gum, (B) 5-100 parts by weight of a reinforcing silica filler, and (C) 0.1-30 parts by weight of a processing aid are fed batchwise to a closed mixer for mixing them until uniform. In a second step, the mixture is continuously fed into a kneader/extruder for heat treating. The first step achieves quick dispersion and cooperates with the second step for the efficient production of a heat-curable silicone rubber compound.

Method for preparing heat-curable silicone rubber compounds

In a first step, basic components including (A) 100 parts by weight of an organopolysiloxane gum, (B) 5-100 parts by weight of a reinforcing silica filler, and (C) 0.1-30 parts by weight of a processing aid are fed batchwise to a closed mixer for mixing them at a temperature of room temperature to 150.degree. C. In a second step, the mixture is fed into a kneader/mixer for heat treating at a temperature of 150-250.degree. C. The first step achieves quick dispersion and cooperates with the second step to form a heat-curable silicone rubber compound in an efficient manner.

A silicone rubber is prepared from a silicone rubber compound comprising (A) an organopolysiloxane having an average degree of polymerization of at least 100, (B) a reinforcing silica filler, and (C) an organohydrogenpolysiloxane by mixing component (C) with components (A) and (B) and heating them at a temperature of at least 100.degree. C. to form the silicone rubber compound, adding an organic peroxide or a platinum group metal catalyst to the compound, and crosslinking the compound. The silicone rubber exhibits a minimal difference in physical properties between primary vulcanization and secondary vulcanization.

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Annaka, Japan

Minoru Igarashi