New Japan Chemical Co., Ltd.

Shoji Tani

Kenji Nishio

Tomio Nobe

Harutomo Nomoto

Masahiko Yamanaka

Shigeo Takatsuji

Kiyoshi Iwahashi

Hiroyuki Kanamaru

Shigeki Hashimoto

Disclosed are an epoxidized polyester which comprises, per molecule, at least three bifunctional groups each having the general formula ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and each is a hydrogen atom or an alkyl group containing 1 to 5 carbon atoms, or R.sup.1 and R.sup.2 taken together represent an endomethylene group, and which has a number average molecular weight of about 1,000 to about 10,000, as well as processes for preparing the epoxidized polyester.

Epoxidized polyesters and method of production thereof

This invention provides a process for producing methyltetrahydrophthalic anhydride characterized in that maleic anhydride and a C.sub.5 fraction are subjected to Diels-Alder reaction in the presence of a radical polymerization inhibitor and oxygen. According to the process of this invention, formation of gels as byproduct is substantially completely inhibited.

Process for production of methyltetrahydrophthalic anhydride

Disclosed is a process for preparing 3,4,5,6-tetrahydrophthalimide comprising the steps of:

Process for preparation of 3,4,5,6- tetrahydrophthalimide

Disclosed is a curing agent composition for epoxy resin, prepared by mixing together the following components (i), (ii) and (iii) and heating the mixture for modification:

Curing agent compositions for epoxy resins and epoxy resin compositions

.DELTA..sup.1 -THPA or a derivative thereof is prepared by isomerizing .DELTA..sup.4 -THPA or a derivative thereof in the presence of (a) a palladium catalyst, and (b) an inorganic salt and/or a sulfur compound.

Growing community of inventors

Nishinomiya, Japan

Shoji Tani