The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 30, 1991
Filed:
Oct. 31, 1990
Kazuyuki Yamasaki, Chiba, JP;
Kimio Yamamoto, Ichihara, JP;
Masanobu Watanabe, Ichihara, JP;
Kojiro Kan, Ichihara, JP;
Yoshio Nakayama, Ichihara, JP;
Mitsui Petrochemical Industries, Ltd., Tokyo, JP;
Abstract
A membrane filter material formed from a solvent resistant bimaleimide polymer which is formed by polymerizing a bismaleimide compound with a perhydrodiaza-type heterocyclic compound and has a main structural skeleton represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 represents a lower carbon chain which is linear or contains a methyl group or ethyl group on the side chain, R.sub.5 represents a divalent group containing an aromatic ring, Y is >R< or >N--R--N< in which R is a lower carbon chain, and m is 0 or 1. This bismaleimide polymer can be a membrane filter material having an excellent organic solvent resistance. When this polymer is formed into a hollow fiber or plain film, a high separating and filtering capacity and an excellent organic resistance can be attained. A membrane filter material having an enhanced organic solvent resistance is provided by preparing the bismaleimide polymer by reacting the bismaleimide compound and perhydrodiaza-type heterocyclic compound in a halogen-containing organic solvent in the present of a small amount of a phenol.