Polarizable amines and polyimides for optical alignment of liquid crystals

• US 6,084,057 A
• Filed: 05/20/1997
• Issued: 07/04/2000
• Est. Priority Date: 05/20/1997
• Status: Expired due to Fees

• Current Assignee: Elsicon Incorporated
• Original Assignee: Elsicon Incorporated
• Inventors: Gibbons, Wayne M., Shannon, Paul J., Zheng, Hanxing
• Primary Examiner(s): BARTS, SAMUEL A
• Application Number:
  US08/859,404
• Time in Patent Office: 1,141 Days
• Field of Search: 528/353, 528/125, 528/128, 528/170
• US Class Current: 528/353
• CPC Class Codes: C08G 73/1039 comprising halogen-containing substituents
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: C09K 2323/02 Alignment layer characterised by chemical composition
• CPC Class Codes: C09K 2323/027 Polyimide
• CPC Class Codes: G02F 1/133723 Polyimide, polyamide-imide
• CPC Class Codes: Y10T 428/31721 Of polyimide

Abstract

The present invention relates to amine compositions and the preparation of polyimides. The polyimides can be used for inducing alignment of a liquid crystal medium with polarized light in liquid crystal display elements.

Claims

1. A polyamic acid comprising the reaction product of an amine component and at least one tetracarboxylic dianhydride, wherein the amine component comprises a polarizable diamine and the polyamic acid is characterized by the formula ##STR21## wherein A is a trivalent organic moiety, L_f is a divalent organic radical comprising at least four fluorinated carbon atoms;

P is a polar group comprising a Pi electron system containing at least one heteroatom selected from the group N, O and S; and

M is a tetravalent organic radical containing at least two carbon atoms, with no more than two carbonyl groups being attached to any one carbon atom of the tetravalent radical.

2. A polyimide derived from the polyamic acid of claim 1.

3. A polyimide derived from the polyamic acid of claim 1 wherein about from 2 to 10 mol % of the amine component for the polyamic acid is monoamine.

4. A polyimide of claim 3 wherein about from 4 to 8 mol % of the amine component for the polyamic acid is monoamine.

5. A polyamic acid of claim 1 wherein M comprises at least one tetravalent organic moiety of the general formula ##STR22## wherein X₂ is independently selected from the group H, CL, F, Br, R₁ and R₁ O--, wherein R₁ is independently selected from C₁ -C₃ perfluorinated alkyl chain, C₁ -C₃ partially fluorinated alkyl chain and C₁ -C₈ hydrocarbon chain;

m is 1 or 0; and

Z is selected from the group --S--, --O--, --SO₂ --, --CH₂ --, --C(CF₃)₂ --, --C(O)--, --CH₂ CH₂ --, --NR-- and a covalent bond wherein R is a C₁ -C₄ hydrocarbon chain.

6. A polyamic acid of claim 5 wherein X₂ is selected from the group H and Cl, and m is 0.

7. A polyamic acid of claim 6 wherein X₂ is H and m is 0.

8. A polyimide derived from the polyamic acid of claim 6.

9. A polyimide derived from the polyamic acid of claim 7.

10. A polyamic acid of claim 7 wherein A is selected from the group consisting of ##STR23## P is selected from the group consisting of:

##STR24## wherein --X₃ is selected from the group --N(R₂)₂, --CN, and --NO₂, t is equal to 0-4;

L_f consists essentially of;

space="preserve" listing-type="equation">--X--(CH.sub.2).sub.n --(CF.sub.2).sub.p --(CH.sub.2).sub.n --X--

wherein --(CF₂)_p -- is a straight chain or branched chain perfluoroalkyl radical, p is 4-20, X is selected from the group consisting of a covalent bond, --O--, --S-- and --NR--, wherein R is selected from H and C₁ -C₄ hydrocarbon, and n is up to 4.

11. A polyamic acid of claim 10 wherein A is ##STR25## P is ##STR26## wherein X₃ is --CN, t is equal to 4;

within --L_f --, X is O, n is 1 and p is 4.

12. A polyamic acid of claim 5 wherein the amine component further comprises about from 1 to 5 mol % 4-(1H,1H-dihydroperfluorooctyloxy)benzenediamine;

and wherein the polarizable diamine comprises about from 2 to 12 mol % of the amine component.

13. A polyimide derived from the polyamic acid of claim 5.