Hitachi, Ltd.

Hitachi Chemical Company, Ltd.

Hitachi Cable, Inc.

Junji Mukai

Hitoshi Yokono

Toshikazu Narahara

Akio Nishikawa

Masahiko Ibamoto

Shuji Eguchi

Motoyo Wajima

Seikichi Tanno

Shunichi Numata

Hideki Asano

Noriaki Taketani

Shun-ichi Numata

Tadashi Muroi

Akira Endo

Tomiya Abe

Hiroshi Suzuki

Mikio Sato

Daisuke Makino

Katuo Sugawara

Junichi Katagiri

Reishi Naka

Yoshiaki Wakashima

Tohru Koyama

Toru Koyama

Masahiko Sakai

Yoshiharu Karasawa

Masato Shimura

Kazuo Goto

Mineo Nakano

Yuuetsu Takuma

Yukio Shimazaki

Goro Tanaka

Mikio Manabe

Hiroko Ohayashi

Ryuichi Simizu

An optical part for light transmission comprises a light conductor formed of a core of a transparent material and a clad of a material having a smaller refractive index than that of the core material, and a light emitting and/or receiving element, wherein the light emitting and/or receiving element is integrally combined with the core of the light conductor by a same material as the core material or by a material having a same refractive index as that of the core material and having a greater rigidity than that of the material forming the clad and/or jacket. The optical part can be used in a high temperature environment as well as a room temperature environment without involving any appreciable loss in light transmission.

Optical part including integral combination of optical fiber and light

There is provided a resinous optical transmitting element in which a core, through which light is transmitted, is formed into a predetermined non-linear configuration, and a cladding lower in refractive index than the core is in close contact with the core. A method of manufacturing the optical transmitting element comprises the steps of polymerizing polymeric material forming the core, within a mold having a predetermined non-linear cavity, subsequently removing the mold, and forming the cladding about the core. The resinous optical transmitting element obtained by the method can be formed into a selected one of various configurations in compliance with the purpose. In addition, the resinous optical transmitting element is less in distortion, making it possible to reduce the transmission loss.

Method of molding a resinous optical transmitting element

A thermosetting resin composition comprising (a) a polyfunctional maleimide, (b) at least one member selected from the group consisting of alkenylphenols and alkenylphenol ethers, and (c) an allyl ester of polyvalent carboxylic acid, or cyanuric or isocyanuric acid and a prepolymer obtained by preliminarily heating the thermosetting resin composition can be used as a solventless type varnish for impregnating, e.g. electric windings, or for preparing a prepreg, and can give a cured product with heating at 120.degree.-250.degree. C. having excellent heat resistance of class C (180.degree. C. or higher) and electrical insulating properties.

Thermosetting resin composition and prepolymer obtained therefrom

In a semiconductor memory device comprising semiconductor memory elements having such a degree of integration in memory circuits as to produce soft errors by incident .alpha.-rays derived from a packaging material and a package which packages the memory elements and is made from the packaging material, when an .alpha.-rays shielding layer made from a resinous material, which may contain one or more high-purity fillers, containing a total amount of 1 part per billion or less of uranium and thorium is interposed between the memory elements and the package, the generation of soft errors is reduced remarkably.

Semiconductor memories with .alpha. shield

A thermosetting resin composition comprising (A) at least one polyfunctional epoxy compound and (B) at least one polyfunctional nitrile compound and a prepolymer thereof can give a cured product having excellent heat resistance and mechanical properties such as flexibility.

Thermosetting resin composition and prepolymer thereof

A polymerizable, curable resin composition suitable for molding materials, prepreg, powdery paint materials or the like, which comprises a polyepoxide, a uretdione and a tetraphenyl borate-amine complex. This composition has long pot life and good curability by virtue of latent catalytic characteristics of the complex.

Resin compositions containing polyepoxides and uretdiones

A rigid polyurethane foam composition characterized by containing 5 to 20% by weight of hollow-spherical Silas balloons having a particle size of 100 to 300 .mu.(based on the total weight of the polyol and isocyanate components of the polyurethane foam) and 0.2 to 2% by weight of an organosilane compound (based on the total weight of the polyol and isocyanate components of the polyurethane foam and said Silas balloons) in the rigid polyurethane foam.

Polyurethane foam composition

A novel thermosetting resin composition consisting essentially of (a) one equivalent of a polyfunctional epoxy compound containing 10 to 80% by weight of a polyglycidyl ester of a fatty acid, (b) 1.5 to 5 equivalents of a polyfunctional isocyanate compound and (c) 0.01 to 10% by weight of a curing catalyst based on the total weight of the polyfunctional epoxy compound and the polyfunctional isocyanate compound. A cured product having excellent thermal resistance and excellent thermal shock resistance which is suitable for the molding of a large apparatus can be obtained by heating said thermosetting resin composition.

Thermosetting resin composition

A novel thermosetting resin can be obtained by mixing 1 equivalent or more of a polyfunctional isocyanate per 1 equivalent of a polyfunctional epoxide and then carrying out a polymerization reaction of the mixture in the presence of the catalyst which forms isocyanurate rings and oxazolidone rings so as to enable the mixture to form 2 or more isocyanurate rings directly connected with oxazolidone rings through an isocyanate residues. The resulting thermosetting resin has excellent electrical, chemical and impact resistances and excellent self-extinguishing properties. Said resin is used as an electric insulating material.

Novel thermosetting resin and a process for producing same

A novel thermosetting resin composition consisting essentially of (a) an isocyanate group-terminated condensate obtained by reacting a polycarboxylic acid compound having at least one acid anhydride ring with a stoichiometrical excess of a polyfunctional isocyanate compound or said condensate containing the unreacted isocyanate compound, (b) a polyfunctional epoxy compound and (c) a catalyst which forms mainly isocyanurate rings and oxazolidone rings. A cured product having excellent thermal resistance and excellent high temperature strength can be obtained by heating said composition.

Novel thermosetting resin composition and cured product therefrom

Thermosetting resin compositions are obtained by mixing a resinous addition product produced by reacting an isocyanate compound having a molecular weight of 100 to 2000 and containing at least two isocyanate groups in its molecule with an epoxyphenol compound represented by the formula, ##EQU1## wherein R is a bi- or more valent group containing phenyl, R.sub.1 is hydrogen, methyl or ethyl, m and n each are an integer of 1-8, and optionally an ordinary thermosetting epoxy resin, and 0.01 to 10 % by weight of a basic heterocycle forming catalyst based on the weight of said resinous addition product, said isocyanate compound and said epoxyphenol compound being blended so that said OH group may be present in an amount of 1/3 to 1 equivalent per equivalent of said isocyanate group and said epoxy group may be present in an amount of one-fifth to two-thirds equivalent per equivalent of said isocyanate group. The said addition product can be converted into a stable B-stage and is particularly useful as a varnish for prepreg.

Thermosetting resin compositions prepared from isocyanates and

A thermosetting resin composition is derived from a modified novolak-type resin obtained by the reaction of a phenolic compound with an aralkyl halide or ether. The thermosetting resin is composed of 20 to 80 parts by weight of a thermosetting resin prepared by reacting a modified novolak-type resin represented by, for example, the general formula, ##SPC1## Wherein R is an aromatic nucleus, with formaldehyde in the presence of a basic catalyst, and, in admixture therewith, 80 to 20 parts by weight of a thermosetting resin prepared by reacting the above-mentioned modified novolak-type resin with hexamethylenetetramine. The thermosetting resin is quickly curable and gives a cured article excellent in heat resistance.

Thermosetting resins

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Hitachi, Japan

Junji Mukai