Patents Represented by Attorney Moxon and Associates, LLC
  • Patent number: 7820253
    Abstract: A negative birefringence film prepared from a poly(aryletherimide) which is the reaction product of a dianhydride and a diamine, where the dianhydride is 4,4?-[4,4?-(p-phenyleneoxy)isopropylidene]bis(phthalic anhydride) (BisADA), bis(3,4-dicarboxyphenyl)ether dianhydride (ODPA), 4,4?-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride (BPEDA), 1,4-bis(3,4-dicarboxyphenyloxy)phenyl dianhydride (BPQDA), 3,3?,4,4?-tetracarboxylicbiphenyl dianhydride (BPDA), or 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride (6FDA), alone or a mixture with one or more of: 3,3?,4,4?-tetracarboxylicbiphenyl dianhydride (BPDA), 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride (6FDA); and where the diamine is 1,4-bis(2-trifluoromethyl-4-aminophenoxy)-2,5-di(t-butyl)benzene (BTBDA), 3,3?-dimethyl-4,4?-diamino biphenyl (OTOL), or mixtures thereof and wherein when a mixture of dianhydrides is present, they are present in a molar amount of between 99 to 1 (99:1) and 1 to 99 (1:99), and the film has
    Type: Grant
    Filed: October 4, 2007
    Date of Patent: October 26, 2010
    Assignee: Akron Polymer Systems
    Inventors: Frank Harris, Limin Sun, Dong Zhang, Stephen Z. D. Cheng