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:
Jun. 02, 1987
Filed:
Jun. 17, 1986
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
The photosensitive polyimide precursor of the invention has a recurring unit represented by the following general formula [I]: ##STR1## (R.sub.1 represents a tetravalent aromatic hydrocarbon residue; R.sub.2 and R.sub.3 each represent a divalent aromatic or aliphatic hydrocarbon residue; and R.sub.4 represents a divalent aromatic hydrocarbon residue represented by ##STR2## wherein R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11 and R.sub.12, identical or different, each represent hydrogen atom, a halogen group or an alkyl group). The photosensitive polyimide precursor of the invention has a viscosity of 50 centipoises or above as measured at 23.degree. C. in the state of a 10% (by weight) solution in N,N-dimethylacetamide. Its photosensitivity is as high as about 20-100 times that of prior products. After heat cyclization, it exhibits a heat resistance of 400.degree. C. or above. The photosensitive polyimide precursor of the invention can be produced by subjecting a tetracarboxylic acid dianhydride and a diamino compound to a polycondensation reaction in an organic polar solvent.