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US 6,958,192 B2Granted
Polyimides from 2,3,3′,4′-biphenyltetracarboxylic dianhydride and aromatic diamines
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsPaul M. Hergenrother, Joseph G. Smith, Jr., John W. Connell, Kent A. Watson
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Abstract
The present invention relates generally to polyimides. It relates particularly to novel polyimides prepared from 2,3,3′,4′-biphenyltetracarboxylic dianhydride and aromatic diamines. These novel polyimides have low color, good solubility, high thermal emissivity, low solar absorptivity and high tensile strength.
Claims8
A polyimide film prepared from reacting 2,3,3′,4-biphenyltetracarboxylic dianhydride with an aromatic diamine selected from the group consisting of:
- wherein X is selected from the group consisting of:
- wherein R is phenyl and CH3,
- wherein Y is selected from the group consisting of CH3, phenyl, chloro and bromo;
- wherein R1 is CF3 and R2 is H, and
- wherein R1 is H and R2 is CF3;
- and
- further wherein the polyimide film has the following combination of properties:
- a thickness of from about 0.02 mm to about 0.06 mm;
- light transmission at 500 nm of greater than about 60%;
- thermal emissivity of greater than about 0.46;
- solar absorptivity of less than about 0.16;
- and
- tensile strength greater than about 93.8 MPa.
10 more elements
Dependencies are inferred from the claim text.