Tetrapolyimide film containing oxydipthalic dianhydride

Claim 2

A chemically converted tetrapolyimide film for dielectric use in flexible printed circuits and tape automated bonding applications comprising, based on the total molar amount of dianhydride, from 20 to 70 mole % of oxydiphthalic dianhydride and from 30 to 80 mole % of pyromellitic acid dianhydride and, based on the total molar amount of diamine, from 30 to 80 mole % of a phenylene diamine and from 20 to 70 mole % of a diaminodiphenylether, wherein said tetrapolyimide film has an elastic modulus of 400 to 1,000 Kpsi, a coefficient of thermal expansion of 8 to 35 ppm/° C., a coefficient of hygroscopic expansion of 10 to 30 ppm/% RH, a water absorption of less than 4% and an etch rate greater than the same tetrapolyimide film prepared by a thermal conversion process using the same time and temperature conditions.

Claim 3

The tetrapolyimide film of claim 1 wherein the phenylene diamine is p-phenylene diamine and the diaminodiphenyl ether is 4,4'-diaminodiphenyl ether.

Claim 4

The tetrapolyimide film of claim 2 comprising from 30 to 70 mole % of oxydiphthalic dianhydride, 30 to 70 mole % of pyromellitic acid dianhydride, 50 to 80 mole % of p-phenylene diamine and 20 to 50 mole % of 4,4'-diaminodiphenylether.

Claim 5

The tetrapolyimide film of claim 3 comprising 60 mole % of oxydiphthalic dianhydride, 40 mole % of pyromellitic acid dianhydride, 70 mole % of p-phenylene diamine and 30 mole % of 4,4'-diaminodiphenyl ether.

Claim 6

A chemical conversion process for preparing a tetrapolyimide film comprising the steps of: (a) reacting substantially equimolar amounts, based on the total molar amounts of dianhydride and diamine, of oxydiphthalic dianhydride, pyromellitic acid dianhydride, a phenylene diamine, and a diaminodiphenylether in an inert organic solvent for a sufficient time and at a temperature below 175° C., sufficient to form a tetrapolyamide acid solution in said solvent; (b) mixing said tetrapolyamide acid solution with conversion chemicals capable of converting the tetrapolyamide acid to tetrapolyimide; (c) casting or extruding the mixture from step (b) onto a smooth surface to form a tetrapolyamide acid-tetrapolyimide gel film; or alternatively in place of steps (b) and (c), a single step of casting or extruding said tetrapolyamide acid solution into a mixture or solution of conversion chemicals capable of converting the tetrapolyamide acid to a tetrapolyamide acid tetrapolyimide gel film; and (d) heating said gel film from step (c) at a temperature and for a time sufficient to convert said tetrapolyamide acid to tetrapolyimide, wherein said tetrapolyimide film has an elastic modulus of 400 to 1,000 Kpsi, a coefficient of thermal expansion of 8 to 35 ppm/° C., a coefficient of hygroscopic expansion of 10 to 30 ppm/% RH, a water absorption of less than 4% and an etch rate greater than the same tetrapolyimide film prepared by a thermal conversion process using the same time and temperature conditions.

Claim 7

A chemical conversion process for preparing a tetrapolyimide film comprising the steps of: (a) reacting substantially equimolar amounts, based on the total molar amounts of dianhydride and diamine, of oxydiphthalic dianhydride, pyromellitic acid dianhydride, a phenylene diamine, and a diaminodiphenylether in an inert organic solvent for a sufficient time and at a temperature below 175° C., sufficient to form a tetrapolyamide acid solution in said solvent; (b) mixing said tetrapolyamide acid solution with conversion chemicals capable of converting the tetrapolyamide acid to tetrapolyimide; (c) casting or extruding the mixture from step (b) onto a smooth surface to form a tetrapolyamide acid-tetrapolyimide gel film; or alternatively in place of steps (b) and (c), a single step of casting or extruding said tetrapolyamide acid solution into a mixture or solution of conversion chemicals capable of converting the tetrapolyamide acid to a tetrapolyamide acid tetrapolyimide gel film; and (d) heating said gel film from step (c) at a temperature and for a time sufficient to convert said tetrapolyamide acid to tetrapolyimide, wherein said tetrapolyimide film has an elastic modulus of 400 to 1,000 Kpsi, a coefficient of thermal expansion of 8 to 35 ppm/° C., a coefficient of hygroscopic expansion of 10 to 30 ppm/% RH, a water absorption of less than 4% and an etch rate greater than the same tetrapolyimide film prepared by a thermal conversion process using the same time and temperature conditions.

Claim 8

The process of claim 5 wherein the phenylene diamine is p-phenylene diamine and the diaminodiphenyl ether is 4,4'-diaminodiphenyl ether.

Claim 9

The process of claim 6 wherein the tetrapolyimide film comprises on the basis of dianhydride from 20 to 70 mole % of oxydiphthalic dianhydride and from 30 to 80 mole % of pyromellitic acid dianhydride and on the basis of diamine from 30 to 80 mole % of p-phenylene diamine and from 20 to 70 mole % of 4,4'-diaminodiphenyl ether.

Claim 10

The process of claim 7 wherein the tetrapolyimide film comprises from 30 to 70 mole % of oxydiphthalic dianhydride, 30 to 70 mole % of pyromellitic acid dianhydride, 50 to 80 mole % of p-phenylene diamine and 20 to 50 mole % of 4,4'-diaminodiphenyl ether.

Claim 11

The process of claim 8 wherein the tetrapolyimide film comprises 60 mole % of oxydiphthalic dianhydride, 40 mole % of pyromellitic acid dianhydride, 70 mole % of p-phenylene diamine and 30 mole % of 4,4'-diaminodiphenyl ether.

Claim 12

The process of claim 5 wherein the conversion chemicals comprise tertiary amine catalysts and anhydride dehydrating agents.

Claim 13

The process of claim 10 wherein the tertiary amine is beta-picoline and the dehydrating agent is acetic anhydride.

Claim 14

The process of claim 5 wherein the inert organic solvent is selected from the group consisting of N-methyl-2-pyrrolidone, dimethylsulfoxide, N,N-dimethylacetamide, N,N-diethylformamide, N,N-diethylacetamide, N,N-diethylformamide and mixtures thereof.