Liquid crystal display and method for producing the same

1. A liquid crystal display device comprising:

an active matrix substrate having a pixel electrode;

a counter substrate having a counter electrode;

vertical-alignment type liquid crystal layer provided between the active matrix substrate and the counter substrate; and

alignment sustaining layers provided between the active matrix substrate and the liquid crystal layer and between the counter substrate and the liquid crystal layer, the alignment sustaining layers containing a polymerization product resulting from polymerization of a polyfunctional monomer, wherein,

at least one of the active matrix substrate and the counter substrate further includes an alignment film;

the alignment film contains polyimide and a polymerization product resulting from polymerization of another polyfunctional monomer;

wherein the polyfunctional monomer of the polymerization product contained in the alignment film is represented by general formula (1) Pb1-Ab1-(Zb1-Ab2)n-Pb2 (in general formula (1), Pb1 and Pb2 are, independently, acrylate, methacrylate, acrylamide, or methacrylamide; Ab1 and Ab2 represent, independently, 1,4-phenylene, 1,4-cyclohexane or 2,5-thiophene, or naphthalene-(2,6)-diyl or anthracene-(2,7)-diyl; and Zb1 is a —COO— group, a —OCO— group, a —O— group, a —CONH— group or a single bond, where n is 0 or 1); and

wherein at least one of Ab1 and Ab2 is substituted by at least one fluorine group.

2. The liquid crystal display device of claim 1 , wherein the polyfunctional monomer of the polymerization product contained in the alignment film has a plurality of vinyl groups.

3. The liquid crystal display device of claim 1 , wherein the polyfunctional monomer of the polymerization product contained in the alignment film includes a dimethacrylate monomer.

4. The liquid crystal display device of claim 3 , wherein the dimethacrylate monomer is represented by structural formula (1a)

5. The liquid crystal display device of claim 1 , wherein the polyfunctional monomer of the polymerization product contained in the alignment sustaining layers has a plurality of vinyl groups.

6. The liquid crystal display device of claim 5 , wherein the polyfunctional monomer of the polymerization product contained in the alignment sustaining layers is represented by general formula (2) Pa1-Aa1-(Za1-Aa2)n-Pa2 (in general formula (2), Pa1 and Pa2 are, independently, acrylate, methacrylate, acrylamide, or methacrylamide; Aa1 and Aa2 represent, independently, 1,4-phenylene, 1,4-cyclohexane or 2,5-thiophene, or naphthalene-(2,6)-diyl or anthracene-(2,7)-diyl; and Za1 is a —COO— group, a —OCO—group, a —O— group, a —CONH— group or a single bond, where n is 0 or 1).

7. The liquid crystal display device of claim 1 , wherein the polyimide is a polyimide including a structure represented by general formula (3)

8. The liquid crystal display device of claim 7 , wherein the polyimide has a photoreactive functional group.

9. The liquid crystal display device of claim 8 , wherein the photoreactive functional group is one selected from the group consisting of a cinnamate group, a chalcone group, a tolan group, a coumarin group, and an azobenzene group.

10. The liquid crystal display device of claim 1 , wherein the alignment film regulates liquid crystal molecules in the liquid crystal layer so that the liquid crystal molecules are inclined with respect to a normal direction of a principal face of the alignment film in the absence of an applied voltage.

11. The liquid crystal display device of claim 1 , wherein,

the liquid crystal display device has a plurality of pixels; and

in each of the plurality of pixels, the liquid crystal layer has a plurality of liquid crystal domains having respectively different reference alignment azimuths.

12. The liquid crystal display device of claim 11 , wherein the plurality of liquid crystal domains are four liquid crystal domains.

13. A liquid crystal display device comprising:

an active matrix substrate having a pixel electrode;

a counter substrate having a counter electrode;

a vertical-alignment type liquid crystal layer provided between the active matrix substrate and the counter substrate; and

alignment sustaining layers provided between the active matrix substrate and the liquid crystal layer and between the counter substrate and the liquid crystal layer, the alignment sustaining layers containing a polymerization product resulting from polymerization of a polyfunctional monomer, wherein,

at least one of the active matrix substrate and the counter substrate further includes an alignment film;

the alignment film contains polyimide and a polymerization product resulting from polymerization of another polyfunctional monomer;

wherein the polyfunctional monomer of the polymerization product contained in the alignment sustaining layers has a plurality of vinyl groups;

wherein the polyfunctional monomer of the polymerization product contained in the alignment sustaining layers is represented by general formula (2) Pa1-Aa1-(Za1-Aa2)n-Pa2 (in general formula (2), Pa1 and Pa2 are, independently, acrylate, methacrylate, acrylamide, or methacrylamide; Aa1 and Aa2 represent, independently, 1,4-phenylene, 1,4-cyclohexane or 2,5-thiophene, or naphthalene-(2,6)-diyl or anthracene-(2,7)-diyl;

and Za1 is a —COO— group, a —OCO— group, a —O— group, a —CONH— group or a single bond, where n is 0 or 1); and

wherein at least one of Aa1 and Aa2 is substituted by at least one fluorine group.

14. The liquid crystal display device of claim 13 , wherein the polyfunctional monomer of the polymerization product contained in the alignment sustaining layers includes a dimethacrylate monomer.

15. The liquid crystal display device of claim 14 , wherein the dimethacrylate monomer is represented by structural formula (2a)

16. A liquid crystal display device comprising:

an active matrix substrate having a pixel electrode;

a counter substrate having a counter electrode;

a vertical-alignment type liquid crystal layer provided between the active matrix substrate and the counter substrate; and

alignment sustaining layers provided between the active matrix substrate and the liquid crystal layer and between the counter substrate and the liquid crystal layer, the alignment sustaining layers containing a polymerization product resulting from polymerization of a polyfunctional monomer, wherein,

at least one of the active matrix substrate and the counter substrate further includes an alignment film;

the alignment film contains polyimide and a polymerization product resulting from polymerization of another polyfunctional monomer; wherein the polyimide is a polyimide including a structure represented by general formula (3)

wherein the polyimide has a photoreactive functional group;

wherein the polyimide is a polyimide including a structure represented by structural formula (3a)

17. The liquid crystal display device of claim 16 , wherein the polyimide has a vertical alignment group in a side chain thereof.

18. A liquid crystal display device comprising:

an active matrix substrate having a pixel electrode;

a counter substrate having a counter electrode;

a vertical-alignment type liquid crystal layer provided between the active matrix substrate and the counter substrate; and

alignment sustaining layers provided between the active matrix substrate and the liquid crystal layer and between the counter substrate and the liquid crystal layer, the alignment sustaining layers containing a polymerization product resulting from polymerization of a polyfunctional monomer, wherein, at least one of the active matrix substrate and the counter substrate further includes an alignment film;

the alignment film contains polyimide and a polymerization product resulting from polymerization of another polyfunctional monomer;

wherein the polyimide is a polyimide including a structure represented by general formula (3)

wherein the polyimide has a vertical alignment group in a side chain thereof;

wherein the polyimide is a polyimide including a structure represented by structural formula (3b)