Dowa Mining Co., Ltd.

Chisso Corporation

Chisso Petrochemical Corporation

Masami Kimura

Masami Sakuraba

Junji Nakamura

Nobuyoshi Tsukaguchi

Masaya Takahara

Ryushi Shundo

Katsuaki Suganuma

Takayuki Takahashi

Takanori Nakashima

Toshihiro Uwai

Tsutomu Ushioda

Chikashi Okayama

Masato Nakano

Maiko Ito

Choju Nagata

Yukihiro Kitamura

Toshikazu Tanaka

Xiao-Shan Ning

Jun Saito

Kazuhiro Kimura

Yoshitaka Morimoto

Makoto Namioka

Hiroshi Yamazaki

Tomohiro Etou

Yoshiyuki Ohgi

Junichiro Yokota

Yasuhiro Mochizuki

Noriaki Saito

Susumu Shimada

Toshiki Yamamoto

Hirohisa Ishii

Tsuyoshi Yahata

Taketo Hirose

Shouji Kawano

Kunio Gouda

Katsuhiko Ohno

Masataka Sugimoto

Yasuhiko Nakagawa

Mayumi Wakata

Kiyomi Yamamoto

Takashi Ono

Masahiko Wada

Jyunji Nakamura

A polymerizable liquid crystal composition containing compounds represented by the formula (1-1) and the formula (1-2), compounds represented by the formula (2-1) and the formula (2-2), and a compound represented by the formula (3-1):the polymerizable liquid crystal composition having homogeneous, homeotropic, or hybrid alignment, which can be coated on a support substrate, for example, of a transparent plastic film such as a triacetyl cellulose film or cycloolefin polymer film, or glass, and is aligned on a substrate as a polymer film while maintaining the alignment.

Polymerizable liquid crystal composition and polymer thereof

Provided are a liquid-crystal compound and a liquid-crystal composition containing the compound, of which the advantages are that they show nematic hybrid orientation on a rubbed TAC substrate, they are polymerizable in open air and they readily give a polymer having a high degree of polymerization even when exposed to a relatively small total quantity of light. The films formed by photopolymerizing them keep nematic hybrid orientation. The compound is represented by formula (1): wherein Ris a hydrogen or an alkyl; Ris a hydrogen, &#x2014;OCF, etc.; Ais a 1,4-phenylene, etc.; Aand Aare independently a 1,4-cyclohexylene, a 1,4-phenylene, etc.; Xis a single bond, &#x2014;O&#x2014;, etc.; Xand Xare independently a single bond, &#x2014;COO&#x2014;, &#x2014;C&#x2261;C&#x2014;, &#x2014;CONH&#x2014;, etc.; m is an integer of from 0 to 20; and n is 1 or 0.

Photopolymerizable oxetane derivative and liquid-crystal composition containing it

A polymerizable liquid crystal composition containing compounds represented by the formula (1-1) and the formula (1-2), compounds represented by the formula (2-1) and the formula (2-2), and a compound represented by the formula (3-1): the polymerizable liquid crystal composition having homogeneous, homeotropic, or hybrid alignment, which can be coated on a support substrate, for example, of a transparent plastic film such as a triacetyl cellulose film or cycloolefin polymer film, or glass, and is aligned on a substrate as a polymer film while maintaining the alignment.

The present invention provides metallocene compounds which exhibit high polymerization activity for production of highly stereoregular polymers, as well as a production process for olefin polymers which employs olefin polymerization catalysts containing the compounds, and olefin polymers obtained by the production process. A metallocene compound of the present invention is represented by the following general formula (1):YKLMX&#x2003;&#x2003;(1)wherein M represents a titanium atom, zirconium atom or hafnium atom; K and L are fused rings coordinated to M and each independently represents a fused ring of a cyclopentadienyl ring and a 5-membered ring, a fused ring of a cyclopentadienyl ring and a 6-membered ring or a fused ring of a cyclopentadienyl ring and a 7-membered ring; Y is a bridge group crosslinking K and L; and each X is bonded to M; and K and L have a 2-furyl group, substituted 2-furyl group, 2-thienyl group, substituted 2-thienyl group, 2-furfuryl group or substituted 2-furfuryl group on at least one position among each of the 2-positions, 4-positions and 5-positions.

Metallocene compounds, production process for olefin polymers using catalysts containing them and olefin polymers produced by the production process

There is provided a method for producing a metal/ceramic bonding article, the method including the steps of: arranging a metal plateof an overall-rate solid solution type alloy on a ceramic substrateand heating the metal plateand the ceramic substratein a non-oxidizing atmosphere at a temperature of lower than a melting point of the alloy to bond the metal platedirectly to the ceramic substrate. According to this method, it is possible to easily bond an alloy plate directly to a ceramic substrate, and it is possible to inexpensively provide an electronic member for resistance without causing the alloy plate to be deteriorated.

Metal/ceramic bonding article and method for producing same

There is provided a metal/ceramic circuit board capable of eliminating discrepancy during mounting of parts to improve the reliability of mounting of the parts. The metal/ceramic circuit board has a ceramic substrateand a metal circuit plate (a copper plate) bonded to the ceramic substratethe metal circuit plate having a thickness which is more than 0.25 mm and which is less than 0.3 mm, and the metal circuit plate having a skirt spreading length (a dimensional difference between the bottom and top portion of the peripheral edge portion of the metal circuit plate) of less than 50 &#x3bc;m.

Metal/ceramic circuit board

After copper platesare bonded to both sides of a ceramic substratevia a brazing filler metal, UV curing alkali peeling type resistsare applied on predetermined portions of the surfaces of the copper platesto etch undesired portions of the copper platesto form a metal circuit portion. While the resistsare maintained, undesired portions of the brazing filler metaland a reaction product, which is produced by a reaction of the brazing filler metalwith the ceramic substrate, are removed (or undesired portions of the brazing filler metaland a reaction product, which is produced by a reaction of the brazing filler metalwith the ceramic substrate, are removed, and the side portion of the metal circuit portion is etched). Thereafter, the resistsare peeled off, and an Ni&#x2014;P electroless platingis carried out. Thus, in a method for producing a metal/ceramic bonding circuit board, it is possible to easily control the sectional shape of a metal/ceramic bonding circuit board by a smaller number of steps and at low costs, and it is possible to produce a metal/ceramic bonding circuit board which is more reliable with respect to thermal shock resistance and insulation performance.

Method for producing metal/ceramic bonding circuit board

There is provided a method for producing a metal/ceramic bonding article, the method including the steps of: bonding a metal plateof an alloy containing copper and nickel directly to at least one side of a ceramic substrate; applying a resiston a predetermined portion of the metal plateto remove an undesired portion of the metal plateby etching; and removing the resistto form a pattern having a predetermined shape of the alloy on the ceramic substrate. According to this method, it is possible to reduce the displacement failure of parts to improve productivity and to prevent bonding failure during the mounting of a semiconductor device or the like thereon.

The present invention provides a metallocene compound which produces an olefin polymer having a high molecular weight with a high stereoregularity. The metallocene compound has the following formula (1):Q(CHR)(CHR)MXY&#x2003;&#x2003;(1)

Metallocene compound, olefin polymerization catalyst containing the compound, and method for producing an olefin polymer by use of the catalyst

There is provided a method for producing a metal/ceramic bonding article, the method including the steps of: bonding a metal plate of an alloy containing copper and nickel directly to at least one side of a ceramic substrate ; applying a resist on a predetermined portion of the metal plate to remove an undesired portion of the metal plate by etching; and removing the resist to form a pattern having a predetermined shape of the alloy on the ceramic substrate . According to this method, it is possible to reduce the displacement failure of parts to improve productivity and to prevent bonding failure during the mounting of a semiconductor device or the like thereon.

There is provided a metal/ceramic circuit board capable of eliminating discrepancy during mounting of parts to improve the reliability of mounting of the parts. The metal/ceramic circuit board has a ceramic substrate and a metal circuit plate (a copper plate ) bonded to the ceramic substrate the metal circuit plate having a thickness of 0.1 mm to 0.5 mm, and the metal circuit plate having a skirt spreading length (a dimensional difference between the bottom and top portion of the peripheral edge portion of the metal circuit plate) of less than 50 &mgr;m.

There is provided a metal/ceramic bonding article which ensures sufficient thermal shock resistance and has a substrate having a small outside dimension and which has both high reliability and compactness. The metal/ceramic bonding article comprises: a ceramic substrate; and a metal plate bonded to the ceramic substrate via a brazing filler metal, wherein the brazing filler metal protrudes from the bottom face of the metal plate by a length which is longer than 30 &mgr;m and which is 250 &mgr;m or less, or wherein the brazing filler metal protrudes from the bottom face of the metal plate by a length which is 25% or more of the thickness of the metal plate.

Metal/ceramic bonding article

A polypropylene composition comprising 0.001 to 10 parts by weight of a polyethylene having an intrinsic viscosity &lsqb;&eegr;E&rsqb; of 0.01 to less than 15 dl/g s measured in tetralin at 135&deg; C. and 100 parts by weight of a polyolefin comprising at least polypropylene, wherein the polyethylene is finely dispersed as particles with a number average particle diameter of, e.g., 1 to 5000 nm in the polyolefin comprising at least polypropylene. By virtue of the above constitution, the polypropylene composition has excellent transparency and rigidity, is free from the creation of a sweeper roll flow mark in the preparation of a film and substantially free from a neck-in phenomenon of a film, and has high productivity.

Polypropylene composition, process for preparing the same, and polymerization catalyst therefor

Process for producing polypropylene or propylene random copolymer

A metal-ceramic composite substitute is produced by joining a metal plate to a ceramic substrate by using a brazing material in a paste form prepared by adding 10-14 parts by weight of a vehicle to 100 parts by weight of a powder of which the solid centent comprises 90.0&tilde;99.5% of an Ag powder, 0&tilde;9.5% of a Cu powder and 0.5&tilde;4.0% of an active metal powder, and 0.0&tilde;0.9% of a titanium oxide powder if necessary.

Brazing material for use in joining a metal plate to a ceramic substrate

Growing community of inventors

Chiba, Japan

Masami Kimura