Patent Number: 7,820,253

Title: Poly(aryletherimides) for negative birefringent films for LCDs

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 a negative birefringence greater than 0.01, at a thickness of less than 15 .mu.m, when the poly(aryletherimide) is solution cast or coated onto a substrate.

Inventors: Harris; Frank (Boca Raton, FL), Sun; Limin (Copley, OH), Zhang; Dong (Uniontown, OH), Cheng; Stephen Z. D. (Richfield, OH)

Assignee: Akron Polymer Systems

International Classification: G02F 1/13363 (20060101)

Expiration Date: 2018-10-26 0:00:00