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United States Patent | 5,039,776 |
Li ,   et al. | August 13, 1991 |
Fusible polyimide powders are prepared by the process of this invention. An amic acid amine is first prepared by treating equimolar amounts of a 2,2-bis[4-(aminophenoxy)phenyl]-hexafluoropropane with an unsaturated carbocyclic monoanhydride. The amic acid amine is then mixed with an aromatic tetracarboxylic dianhydride and the mixture heated to form a polyimide precursor. A chemical dehydrating agent is added in an amount sufficient to substantially, fully imidize the precursor. The resulting fusible polyimide powder is finally separated.
Inventors: | Li; Hsueh M. (Baton Rouge, LA); Nugent, Jr.; Adam (Baton Rouge, LA) |
Assignee: | Ethyl Corporation (Richmond, VA) |
Appl. No.: | 523349 |
Filed: | May 14, 1990 |
Intern'l Class: | C08G 008/02 |
Field of Search: | 528/125,126,128,229,342,353 |
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4173700 | Nov., 1979 | Green et al. | 528/125. |
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4913759 | Apr., 1990 | Wright | 156/238. |
4923954 | May., 1990 | Klobucar et al. | 528/183. |
4931531 | Jun., 1990 | Tamai et al. | 528/172. |