Polyimides comprising substituted benzidines
First Claim
1. A polyimide which consists of 1 to 100 mole percent of the structural elements of the formula (II) ##STR10## where R is a tetravalent organic radical, each A is selected from the group consisting of a halogenated alkyl group, an aryl group and a substituted-aryl group.
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Accused Products
Abstract
A new class of polyimides and copolyimides made from substituted benzidines and aromatic dianhydrides and other aromatic diamines. The polyimides obtained with said diamines are distinguished by excellent thermal, excellent solubility, excellent electrical properties such as very low dielectric constants, excellent clarity and mechanical properties making the polyimides ideally suited as coating materials for microelectronic apparatii, as membranes for selective molecular or gas separation, as fibers in molecular composites, as high tensile strength, high compression strength fibers, as film castable coatings, or as fabric components.
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Citations
22 Claims
- 1. A polyimide which consists of 1 to 100 mole percent of the structural elements of the formula (II) ##STR10## where R is a tetravalent organic radical, each A is selected from the group consisting of a halogenated alkyl group, an aryl group and a substituted-aryl group.
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10. A film formed from a polyimide consisting of 1 to 100 mole percent of repeat units of formula (II) ##STR11## where R is a tetravalent organic radical, each A is selected from the group consisting of a halogenated alkyl group, an aryl group and a substituted-aryl group, said polyimide characterized by complete solubility in m-cresol, by UV transparency from about 65% to about 100% at 375 nm, a low dielectric constant, and by excellent thermal stability as evidenced by a 5% weight loss at a temperature from about 500°
- C. to about 600°
C. - View Dependent Claims (11, 13, 14, 15)
- C. to about 600°
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12. A polyimide according to claim 69 wherein said halogenated alkyl group is trifluoromethyl.
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16. A fiber formed from a polyimide consisting of 1 to 100 mole percent of repeat units of formula (II) ##STR12## where R is a tetravalent organic radical, each A is selected from the group consisting of a halogenated alkyl group, an aryl group and a substituted-aryl group, said polyimide characterized by complete solubility in m-cresol, by UV transparency from about 65% to about 100% at 375 nm, a low dielectric constant, and by excellent thermal stability as evidenced by a 5% weight loss at a temperature from about 500°
- C. to about 600°
C., said fiber oriented in one direction by being drawn at least two times in said direction and being characterized by high tensile strength in the draw direction, excellent resistance to fibrillation, a high degree of crystallinity in the drawing direction and partially or entirely non-crystalline in a direction perpendicular to the drawing direction. - View Dependent Claims (17, 18, 19, 20, 21)
- C. to about 600°
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22. An elastomeric or resinous fiber composite comprising fibers of a polyimide consisting of 1 to 100 mole percent of repeat units of formula (II) ##STR13## where R is a tetravalent organic radical, each A is selected from the group consisting of a halogenated alkyl group, an aryl group and a substituted-aryl group, said polyimide characterized by complete solubility in m-cresol, by UV transparency from about 65% to about 100% at 375 nm, a low dielectric constant, and excellent thermal stability as evidenced by a 5% weight loss at a temperature from about 500°
- C. to about 600°
C., said fiber oriented in one direction by being drawn at least two times in said direction and being characterized by high tensile strength in the draw direction, excellent resistance to fibrillation, a high degrees of crystallinity in the drawing direction and partially or entirely non-crystalline in a direction perpendicular to the drawing direction.
- C. to about 600°
Specification