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:
Sep. 04, 1990
Filed:
Jun. 01, 1987
Masakazu Uekita, Hyogo, JP;
Hiroshi Awaji, Hyogo, JP;
Kanegafuchi Kagaku Kogyo Kabushiki, Osaka, JP;
Abstract
A copolymerized polyamic acid salt having a recurring unit represented by following formula (I) and (II) and the process for preparing thereof. ##STR1## wherein (A) or (A') represents a formula ##STR2## wherein, R.sup.1 represents a tetravalent group having at least 2 carbon atoms; R.sup.2 represents a divalent group having at least 2 carbon atoms; and R.sup.31, R.sub.32, R.sup.33, R.sup.41, R.sup.42, R.sup.43, R.sup.5, and R.sup.6 each represents a monovalent group having 1 to 30 carbon atoms selected from an aliphatic group, an alicyclic group, an aromatic group, a group in which an aliphatic group is combined with an alicyclic group or an aromatic group, each of these groups substituted by a halogen atom, a nitro group, an amino group, a cyano group, a methoxy group, or an acetoxy group, or a hydrogen atom; at least one of said R.sup.31, R.sup.32, R.sup.33, R.sup.41, R.sup.42, R.sup.43, R.sup.5 and R.sup.6 do not take a group having 1 to 11 carbon atoms or a hydrogen atom; and (B) or (B') represents one or more formula ##STR3## wherein R.sup.1, R.sup.2, R.sup.31, R.sup.32, R.sup.33, R.sup.41, R.sup.42, R.sup.43, R.sup.5 and R.sup.6 are defined in (A); and x and y represents a ratio which satisfies 0 x 1, 0 y 1 and x+y=1. In formula (I) at least one of said R.sup.1, R.sup.2, R.sup.31, R.sup.32, R.sup.33, R.sup.41, R.sup.42, R.sup.43, R.sup.5 and R.sup.6 do not take the same group as defined in (A), and in formula (II) a part of at least one of R.sup.1 and R.sup.2 is substituted by a group having a different valence.