Polarizable amines and polyimides for optical alignment of liquid crystals

• US 6,043,337 A
• Filed: 05/18/1998
• Issued: 03/28/2000
• 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:
  US09/080,883
• Time in Patent Office: 680 Days
• Field of Search: 528/353, 428/1, 428/473.5
• US Class Current: 528/353
• CPC Class Codes: C08G 73/1039 comprising halogen-containing substituents
• CPC Class Codes: C09K 2323/027 Polyimide
• CPC Class Codes: C09K 2323/059 Unsaturated aliphatic polymer, e.g. vinyl
• 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 composition which is the reaction product of an amine component and a tetracarboxylic dianhydride component which comprises at least one structural element of leach of the following formulas:

##STR28## wherein X₄ is an electron withdrawing group having a positive σ

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

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 --CH₂ O--, --CH₂ S--, --CH₂ NR--, --O--, --S--, --NR-- and a covalent bond, wherein R is a C₁ -C₄ hydrocarbon, n is up to 4; and

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

2. A polyamic acid composition of claim 1 wherein:

X₄ is selected from the group --CN, --CF₃, F, Cl, Br, I, --NO₂, --CO₂ R₂, and --CON(R₂)₂, wherein R₂ is H or a C₁ -C₄ hydrocarbon;

A is an aromatic ring selected from the group consisting of;

##STR29## P is selected from the group of;

##STR30## wherein X₃ is selected from the group --N(R₂)₂, --CN, --NO₂ and t is equal up to 4;

within L_f, is selected from --CH₂ O-- and --O--, p is 4-12 and n is 1 to 3; and

M is ##STR31## wherein X₂ is independently selected from the group H, Cl, F, Br, R₁, R₁ O--, wherein R₁ s independently selected from C₁ -C₃ perfluorinated alkyl chain, C₁ -C₃ partially perfluorinated 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; and

the acid groups are ortho to the amide linkages.

3. A polyamic acid composition of claim 2 wherein X₄ is selected from the group --CN, --CF₃ ;

and within M, X₂ is selected from H and Cl, and m is 0.

4. A polyamic acid composition of claim 3 wherein X₂ is H.

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

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

7. A liquid crystal display element made from a composition of a polyimide of claim 5.

8. A liquid crystal display element made from a composition of a polyimide of claim 6.