E.i. Dupont De Nemours and Company

Richard F Sutton, Jr

John A Kreuz

Stuart N Milligan

Darrel Eugene Coverdell

An intimate polyimide blend, prepared by chemical conversion, containing from 25 to 50 weight % of a first polyimide derived from 90 to 100 mole % of 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 0 to 10 mole % of pyromellitic dianhydride and p-phenylenediamine and from 50 to 75 weight % of a second polyimide derived from pyromellitic dianhydride, from 20 to 50 mole % of p-phenylenediamine and from 50 to 80 mole % of 4,4'-diaminodiphenylether. The polyimide blend provides blister free films having high modulus and low thermal expansion coefficients for use in electronics applications.

High modulus polyimide blend

Tetrapolyimide films derived from 3,3',4,4'-benzophenone tetracarboxylic dianhydride, pyromellitic acid dianhydride, p-phenylene diamine and 4,4'-diaminodiphenyl ether, and their preparation, are described. The tetrapolymer films have low water absorption, low coefficients of thermal and hygroscopic expansion, high modulus and are caustic etachable and can be used in flexible printed circuit and tape automated bonding applications.

Tetrapolyimide film containing benzophenone tetracarboxylic dianhydride

Disclosed is an aromatic copolyimide film prepared by chemical conversion of a copolyamide acid solution obtained by copolymerization of an aromatic tetracarboxylic acid component comprising from 30 to 50 mole % of biphenyltetracarboxylic acid dianhydride, 50 to 70 mole % of pyromellitic acid dianhydride, 60 to 80 mole % of p-phenylenediamine and 20 to 40 mole % of 4,4'-diaminodiphenyl ether. The aromatic copolyimide film has a low coefficient of thermal expansion, low water absorption, a low coefficient of hygroscopic expansion, high mechanical strength and is readily etchable making it suitable for use an advanced electronic substrate.

Copolyimide film with improved properties

Extraction of polyamic acid-polyimide gel in bipolymerized polyimide manufacturing process with a solvent containing an extraction-enhancing agent, which is a pyridine, picoline, or quinoline, leads to a polyimide film having increased molecular weight. Polyimides are valuable materials used in fabricating articles which must withstand high temperatures, especially in aerospace applications, and in the manufacture of electronic circuit boards.

Polyimide molecular weight enhancement by solvent extraction

An improved process for preparing polyimides is disclosed which involves end capping intermediate polyamic acids with dicarboxylic acid monoanhydrides and thermally converting to high molecular weight polyimides.

Process for preparing polyimides

A process is disclosed for manufacturing high molecular weight polyimide from a chilled solution which includes a polyamide acid prepolymer, a finishing component, and a converting system wherein, when the solution is heated, polyamide acid polymer is formed and converted to polyimide.

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Circleville, OH, United States of America

Richard F Sutton, Jr