Preparing a flexible display substrate with a mixture of tetra acids or tetra acid derivatives and polyamic acids
AssigneeAkron Polymer Systems, Inc.
InventorsZhen Li, Lang Hu, Limin Sun, Frank W. Harris, Dong Zhang
Life of this patent
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Abstract
A process for the preparation of an aromatic polyimide substrate for optical displays that can be carried out during the manufacture of a display, which includes the steps of coating a solution of an aromatic tetracarboxylic acid or an aromatic tetracarboxylic acid derivative and a low molecular weight polyamic acid on a solid support and subsequent heating. The polyamic acid is prepared from non-stoichiometric amounts of 3,3′,4,4′-biphenyltetracarboxylic dianhydride and p-phenylenediamine.
Claims16
A process for the preparation of an aromatic polyimide substrate for optical displays that can be carried out during the manufacture of the display, the process comprising the steps of:
- casting a solution of an aromatic tetracarboxylic acid or an aromatic tetracarboxylic acid derivative and a low molecular weight polyamic acid in a polar organic solvent on a solid support in the form of a film, said polyamic acid obtained by polymerizing 3,3′4,4′-biphenyltetracarboxylic dianhydride with an excess of p-phenylenediamine, said aromatic tetracarboxylic acid and aromatic tetracarboxylic acid derivative having the structures:
- wherein R1 is,
- and wherein R2 is hydrogen or an alkyl group or mixtures of the two;
- evaporating solvent to afford a polyamic acid film;
- and
- heating the polyamic acid film on the support to a temperature of not lower than 425° C. to prepare the aromatic polyimide substrate.
Dependencies are inferred from the claim text.