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:
Aug. 29, 1989
Filed:
Jun. 01, 1988
Akitoshi Sugio, Yokkaichi, JP;
Takao Kawaki, Tokyo, JP;
Makoto Kobayashi, Nagareyama, JP;
Katsushige Hayashi, Matsudo, JP;
Masahito Watanabe, Tokyo, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
A photosensitive polyimide precursor composed of the structural units (A) represented by the following general formula (I) and the structural units (B) represented by the following general formula (II), in which the ratio of the molar quantity of the structural units (A) to the sum of the molar quantity of the structural units (A) and that of the structural units (B) is 0.01 or greater, and having a viscosity of 100 cP or above as measured at 25.degree. C. in the state of a 10% by weight solution in N-methylpyrrolidone: ##STR1## wherein R.sub.1 represents a tetravalent aromatic hydrocarbon residue; R.sub.2 represents a divalent aromatic hydrocarbon residue; X, identical or different represents a halogen or an alkyl group; and m represents 0 or an integer from 1 to 4. The photosensitivity of the present photosensitive polyimide precursor is about 20 to 100 times that of conventional products. After heat dehydration cyclization, it shows a heat resistance of 400.degree. C. or above.