Process for producing highly adherent silicon-containing polyamic acid and corsslinked silicon-containing polyimide

Claim 1

A process for producing a silicon-containing polyamic acid having an inherent viscosity of 0.05 to 5 dl/g as measured in a concentration of 0.5% by weight in a solvent at a temperature of 30±0.01° C., which process comprises either (a) reacting at least a part of A moles of a tetracarboxylic acid dianhydride expressed by the following formula (1) with B mols of a diamine expressed by the following formula (2), then adding to the resulting reaction product or mixture, C mols of an aminosilicon compound expressed by the following formula (3), and any remainder of the A moles of the same tetracarboxylic acid dianhydride, and reacting the resulting mixture, or (b) reacting A mols of a tetracarboxylic acid dianhydride expressed by the following formula (1) with a mixture of B mols of a diamine expressed by the following formula (2) and C mols of an aminosilicon compound expressed by the formula (3), wherein the moles A, B and C satisfy the following expressions (4) and (5): ##STR15## wherein R 1 represents a tetravalent carbocyclic aromatic group; R 2 represents a divalent group selected from the group consisting of (a) an aliphatic group of 2 to 12 carbon atoms, (b) an alicyclic group of 4 to 30 carbon atoms, (c) an aromatic aliphatic group of 6 to 30 carbon atoms, (d) a carbocyclic aromatic group of 6 to 30 carbon atoms, (e) a polysiloxane group expressed by the formula (6) ##STR16## wherein each R 5 independently represents ##STR17## wherein s represents an integer of 1 to 4, each R 6 independently represents an alkyl group of 1 to 6 carbon atoms, a phenyl group or an alkyl-substituted phenyl group of 7 to 12 carbon atoms, and l represents a value of 1≦l≦100, and (f) a group expressed by the formula ##STR18## wherein R 8 represents an aliphatic group or an aromatic aliphatic group each of 8 carbon atoms or less, or a hydrogen atom; R 3 represents ##STR19## each R 4 independently represents an alkyl group of 1 to 6 carbon atoms, a phenyl group or an alkyl-substituted phenyl group of 7 to 12 carbon atoms; each X independently represents an alkoxy group, an acetoxy group or a halogen atom; and k is a value of 1≦k≦3.