Poly amic acid system for polyimides
AssigneeMedtronic, Inc.
InventorLisa Scott
Life of this patent
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Abstract
A poly amic acid precursor containing a combination of tetrahydrofuran and N-methylpyrrolidinone as cosolvents is described. Utilizing the combination of tetrahydrofuran and N-methylpyrrolidinone allows for the removal of significant portions of the solvent during the formation of the polyimide. The removal of tetrahydrofuran and N-methylpyrrolidinone can be done without the use of preheating zones so as to allow for the large scale production of polyimide articles.
Claims26
A poly amic acid precursor comprising at least one anhydride and at least one diamine in a cosolvent of tetrahydrofuran and N-methylpyrrolidinone.
A polyamic acid precursor comprising:
- 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 4,4′-oxydiphthalic anhydride in a molar ratio of about 50% 3,3′,4,4′-biphenyltetracarboxylic dianhydride;
- 3,4′-oxydianiline in a molar ratio of about 50% 3,4′-oxydianiline to 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 4,4′-oxydiphthalic anhydride;
- and
- a cosolvent comprising about 70% tetrahydrofuran and about 30% N-methylpyrrolidinone by volume of cosolvent.
A method for producing a polyimide comprising:
- heating a poly amic acid precursor comprising at least one anhydride and at least one diamine in a cosolvent of tetrahydrofuran and N-methylpyrrolidinone, wherein said tetrahydrofuran is in an amount ranging from about 1% to about 90% by volume of tetrahydrofuran and N-methylpyrrolidinone, whereby a portion of the cosolvent is removed and a polyimide is formed.
A polyimide laminate comprising:
- a polyimide layer;
- and
- a metal foil, wherein said polyimide laminate is produced by casting a polyamic acid precursor comprising at least one diamine and at least one anhydride in a cosolvent of tetrahydrofuran and N-methylpyrrolidinoneonto a surface of the metal foil, followed by heating the polyamic acid solution to form the polyimide layer.
A process for producing a polyimide laminate comprising the steps of:
- adding a poly amic acid precursor onto a surface of a substrate, wherein the polyamic acid precursor comprises at least one diamine and at least one anhydride in a cosolvent of tetrahydrofuran and N-methylpyrrolidinone, wherein said tetrahydrofuran is in an amount ranging from about 1% to about 90% by volume of tetrahydrofuran and N-methylpyrrolidinone;
- and
- heating the poly amic acid precursor on the substrate to remove tetrahydrofuran and N-methylpyrrolidinone therby forming a polyimide laminate.
Dependencies are inferred from the claim text.