Polyimide varnish
AssigneeNissan Chemical Industries, Ltd.
InventorsMakoto Mishina, Terumi Sato, Hiroyoshi Fukuro
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Abstract
A polyimide varnish which is a solution having a polyimide and/or a polyimide precursor dissolved in an organic solvent and which is useful for forming a polyimide coating film on a substrate by coating the solution on the substrate followed by heat treatment, wherein from 5 wt % to 60 wt % of the organic solvent is a polypropylene glycol derivative of the formula (I): ##STR1## wherein n is 1 or 2, and R is hydrogen, a C.sub.1-4 alkyl group, a C.sub.1-4 alkenyl group or a C.sub.1-4 alkanoyl group.
Claims8
A method of forming a polyimide coating film having a thickness of from 0.05 .mu.m to 0.2 .mu.m as a liquid crystal alignment film on a silicon substrate having wiring applied thereto or a transparent substrate of glass sheet or plastic film provided with a transparent electrode, which comprises coating a solution having a polyimide or polyimide precursor or both dissolved in an organic solvent on the substrate by spin coating or flexoprinting, followed by heat treatment, wherein from 5 wt. % to 60 wt. % of the organic solvent is a propylene glycol of the formula (I):
- ##STR4## wherein n is 1 or 2, and R is independently hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkenyl, C.sub.1 -C.sub.4 alkanoyl or phenyl.
Dependencies are inferred from the claim text.