Methods and compositions for producing polyimide coatings
First Claim
Patent Images
1. A method of forming a coating on a surface which comprises the steps of:
- providing a quantity of a solvent;
adding thereto in either order, an aromatic tetracarboxylic acid dianhydride and from just above 0 to 10 moles of an oxoimine per mole of said dianhydride, said oxoimine having the general structure. ##STR4## where x is 4 to 7;
maintaining the resulting mixture at a temperature of from about 30°
to 120°
C.;
stirring said mixture until solution is complete;
cooling the resulting solution to a temperature of from about 20°
to 60°
C.;
adding thereto about 1.0 moles of a diamine per mole of dianhydride;
stirring until solution is complete;
forming a layer of said material having a thickness of up to about 3 mils on a surface; and
heating said material to a temperature of from about 175°
to 320°
C. for from about 30 minutes to 5 hours to form a smooth, adherent coating of a high molecular weight polymer.
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Abstract
Methods and compositions for producing imide precursors and polyimide coating and adhesives. Basically a mixture of an oxoimine such as caprolactam, a dianhydride such as 3,3'"'"', 4,4'"'"'-benzophenone tetracarboxylic acid dianhydride and a solvent such as dimethyl formamide is heated to a temperature of about 60° to 120° C. for a suitable period, then the mixture is cooled and a suitable diamine is added to produce the imide precursor. This mixture may be dried to a powder form or may be used directly as a coating or adhesive. The final polyimide is produced by heating the precursor to a suitable temperature over an appropriate period.
20 Citations
23 Claims
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1. A method of forming a coating on a surface which comprises the steps of:
-
providing a quantity of a solvent; adding thereto in either order, an aromatic tetracarboxylic acid dianhydride and from just above 0 to 10 moles of an oxoimine per mole of said dianhydride, said oxoimine having the general structure. ##STR4## where x is 4 to 7;
maintaining the resulting mixture at a temperature of from about 30°
to 120°
C.;stirring said mixture until solution is complete; cooling the resulting solution to a temperature of from about 20°
to 60°
C.;adding thereto about 1.0 moles of a diamine per mole of dianhydride; stirring until solution is complete; forming a layer of said material having a thickness of up to about 3 mils on a surface; and heating said material to a temperature of from about 175°
to 320°
C. for from about 30 minutes to 5 hours to form a smooth, adherent coating of a high molecular weight polymer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification