Photo-alignment film and liquid crystal display element
AssigneesJnc Corporation, Chisso Petrochemical Corporation
InventorNorio Tamura
Life of this patent
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Abstract
[Object] To obtain an alignment film having excellent alignment stability of a liquid crystal and a high voltage holding ratio by application of linearly polarized light to a polyamic acid having a specific structure and then imidization under heat. [Solving Means] A photo-alignment film is obtained by: applying a polyamic acid solution on a substrate, where the polyamic acid contains, in its main chain, at least a group having unsaturated groups having 1 to 3 carbon-carbon double bonds or 1 to 4 triple bonds; vaporizing a solvent from a film formed; applying linearly polarized light to the film after the vaporization of the solvent; and then heating the film to imidize the polyamic acid.
Claims15
A photo-alignment film, which is formed by imidization after alignment of a polyamic acid generated using at least a diamine and a tetracarboxylic acid dianhydride as raw materials by light irradiation in a predetermined direction, wherein:
- the diamine comprises one or more diamines containing an unsaturated bond each represented by a general formula (1) described below as component A of the diamine;
- the tetracarboxylic acid dianhydride comprises one or more tetracarboxylic acid dianhydrides containing an unsaturated bond each represented by a general formula (2) described below as component A of the tetracarboxylic acid dianhydride;
- or
- the diamine comprises the one or more diamines containing unsaturated bonds as component A of the diamine, and the tetracarboxylic acid dianhydride comprises the one or two or more tetracarboxylic acid dianhydrides containing unsaturated bonds as component A of the tetracarboxylic acid dianhydride:
- H2N-A1-T-A2-NH2 (1)
- where A1 and A2 each independently represent a divalent organic group, and T represents a divalent group comprising an unsaturated bond containing 1 to 3 carbon-carbon double bonds or 1 to 4 triple bond;
- where A3 and A4 each independently represent a trivalent organic group, and T represents a divalent group comprising an unsaturated bond containing 1 to 3 carbon-carbon double bonds or 1 to 4 triple bonds.
A photo-alignment film, which is formed by imidization after alignment of a polyamic acid generated using at least a diamine and a tetracarboxylic acid dianhydride as raw materials by light irradiation in a predetermined direction, wherein:
- the diamine and the tetracarboxylic acid dianhydride comprise one or both of
- one or more diamines selected from the group consisting of structural formulae (1-1) to (1-11) described below as component A of the diamine as the diamine and
- one or more tetracarboxylic acid dianhydrides selected from the group consisting of structural formulae (2-1) to (2-7) described below as component A of the tetracarboxylic acid dianhydride as the tetracarboxylic acid dianhydride;
- and
- the diamine and the tetracarboxylic acid dianhydride further comprise one or both of
- one or more diamines selected from the group consisting of general formulae (3-1) and (3-3) to (3-7) described below and a structural formula (3-2) described below as component B of the diamine as the diamine and
- one or more tetracarboxylic acid dianhydrides selected from the group consisting of a general formula (4-2) described below and structural formulae (4-1) and (4-3) to 4-7) described below as component B of the tetracarboxylic acid dianhydride as the tetracarboxylic acid dianhydride:
- where X40represents —O—or —S—, X41's each independently represent —CH2—, —CH2CH2—, or —O—, R40represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R41 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, n represents an integral number of 1 to 6, m's each independently represent 1 or 2, and p represents an integral number of 0 to 2;
- where R42, R43, R44, and R45 each independently represent a hydrogen atom or a methyl group.
Dependencies are inferred from the claim text.