Nippon Kayaku Kabushiki Kaisha

Unitika Ltd.

Gun Ei Chemical Industry Co., Ltd.

Ryoichi Hasegawa

Hiroaki Ohno

Kenichi Kuboki

Yoshio Shimamura

Yoshinori Saito

Kazuaki Sano

Makoto Uchida

Yoshiaki Echigo

Takeshi Yoshida

Shigeru Aoki

Yasuhisa Tashiro

Yasumasa Akatsuka

Akira Shigeta

Yoshiaki Kurimoto

Yukio Abe

Akikazu Mitsunobu

Akiyuki Kojima

Minoru Noji

Hiroaki Nishiyama

Mamoru Katagiri

Jun-ichi Mori

Shin'ichi Umeda

Seiichi Hayashi

A method for preparing a substrate for a flexible print wiring board having a polyimide based resin layer wherein a solution of a polyimide based resin precursor is directly applied on an electrically conducting material to form a polyimide based resin precursor layer and then the precursor layer is cured by heating to prepare a polyimide based resin layer, characterized in that a solution of a polyimide based resin precursor B, which is one of solutions of two types of polyimide based resin precursors, is directly applied on an electrically conducting material and then, on the resultant layer is applied a solution of a polyimide based resin precursor A which allows resolving the residual strain generated in the polyimide based resin formed by the curing of the above polyimide based resin precursor B.

Method for preparing substrate for flexible print wiring board, and substrate for flexible print wiring board

Epoxy resin, epoxy resin composition and hardened product thereof

An object is to provide hardened products having excellent water resistance and mechanical strength, and an epoxy resin and an epoxy resin composition for use in the production thereof. An epoxy resin obtained by the glycidylation of a novolak type resin which is prepared by the condensation of biphenyls with phenols and naphthols, and a resin composition containing said epoxy resin and hardened products thereof.

A process for purifying 7-dimenthylamino-6-demethyl-6-deoxytetracycline represented by the following formula, ##STR1## which comprises dissolving 7-dimethylamino-6-demethyl-6-deoxytetracycline or its hydrochloride having a lower purity in a mixed solvent of an alcohol and water by using hydrochloric acid and then adjusting the pH of the solution to 3.5 to 4.5 to recrystallize the hydrochloride having a higher purity.

Process for purifying 7-dimethylamino-6-demethyl-6-deoxytetracycline

A process for producing 7-dimethylamino-6-demethyl-6-deoxytetracycline (minocycline) which comprises treating the reaction liquid containing minocycline and formaldehyde with hydroxylamine or urea, the reaction liquid being obtained after reductive methylation of 7-amino-6-demethyl-6-deoxytetracycline by using aldehyde, then subjecting the reaction liquid to an adsorption treatment with a nonionic adsorption resin (adsorbent), and subsequently eluting the intended product adsorbed to the adsorbent.

Process for producing 7-dimethylamino-6-demethyl-6-deoxytetracycline

This invention relates to a process for producing optically active phenylalanine, characterized by optically resolving DL-phenylalanine.optically active mandelic acid complexes in an aqueous solvent in the presence of an acidic compound having a pKa value of 0.90 to 2.10 and isolating optically active phenylalanine from the obtained optically active phenylalanine.optically active mandelic acid complex. According to the process of the present invention, it is possible to decrease the amount of a mother liquor of resolution to 1/5 to 1/10 of that when no acidic compound is used and to obtain optically active phenylalanine having an optical purity of as high as 96.5% or above without a step of optical purification when optically active phenylalanine is isolated from the obtained optically active phenylalanine.optically active mandelic acid complex.

Process for producing optically active phenylalanine

Process for producing substituted or unsubstituted naphthalic acids and acid anhydrides thereof by oxidation of corresponding acenaphthenes whose naphthalene nucleus may have one or two substituents from the group consisting of halogens, sulfonic acid groups, sulfonate groups, and nitro. The oxidation is performed at 30.degree.-150.degree. C. using molecular oxygen in the presence of (1) at least one heavy metal compound, such as cobalt acetate or manganese acetate, in an amount of 0.005-0.3 mole per mole of said acenaphthenes or a mixture of heavy metal compounds in that amount and a bromine compound in the range of 5.times.10.sup.-5 to 2.times.10.sup.-1 mole/liter of reaction solution as a catalyst and (2) at least one accelerator selected from the group consisting of lower fatty acid anhydrides, ketones and aldehydes, whereby side reactions such as condensation can be suppressed to a satisfactory extent, thereby leading to an improvement in yield of final product. A subsequent treatment of the oxidation product obtained by this process with peroxides, hypohalogenates, or molecular oxygen results in a higher yield.

Process for producing substituted or unsubstituted naphthalic acids and

Growing community of inventors

Yono, Japan

Ryoichi Hasegawa