Method of manufacturing liquid crystal display
A liquid crystal display may be manufactured by forming a first alignment layer on a first base substrate, forming a second alignment layer on a second base substrate, disposing liquid crystal on the first alignment layer or the second alignment layer, and combining the first base substrate and the second base substrate with each other. At least one of the first and second alignment layers may be formed by forming an alignment solution including an alignment agent and a cross-linking agent on the first or second base substrate. The alignment solution is cured at a first temperature to form an alignment layer. The base substrate is exposed to light or an electron beam to align the alignment layer. The alignment layer is baked at a second temperature. The first temperature is lower than a cross-linking reaction temperature of the cross-linking agent.
1. A method of manufacturing a liquid crystal display, the method comprising:
forming a first alignment layer on a first base substrate;
forming a second alignment layer on a second base substrate;
disposing liquid crystal on the first alignment layer or the second alignment layer; and
combining the first base substrate and the second base substrate with each other,
wherein the forming of at least one of the first and second alignment layers comprises;
forming an alignment solution on the first or second base substrate, wherein the alignment solution comprises an alignment agent and a cross-linking agent;
curing the alignment solution at a first temperature to form an alignment layer;
exposing the base substrate to light or an electron beam to align the alignment layer; and
baking the alignment layer at a second temperature,
wherein the first temperature is lower than a cross-linking reaction temperature of the cross-linking agent.
2. The method of claim 1 , wherein at least one of the first and second alignment layers comprises a polymer having a photolytic group.
3. The method of claim 2 , wherein the alignment agent comprises a cyclobutane dianhydride or a derivative thereof and a diamine.
4. The method of claim 3 , wherein the alignment agent comprises one or more compounds having Chemical Formula 1, and one or more compounds having Chemical Formula 2:
wherein R 1 , R 2 , R 3 , and R 4 are each independently a hydrogen atom, a fluorine atom, or an alkyl group or alkoxy group having a carbon number of 1 to 6,
wherein R 1 , R 2 , R 3 , and R 4 are each independently a hydrogen atom, a fluorine atom, an alkyl group or alkoxy group having a carbon number of 1 to 6, a vinyl group (—(CH 2 ) m —CH═CH 2 , m=0, 1, or 2), or an acetyl group (—(CH 2 ) n —C≡CH, n=0, 1, or 2), and X is —S—, —CO—, or —NH—.
5. The method of claim 4 , wherein the cross-linking agent comprises an oxirane compound, a melamine compound, an epoxy compound, an isocyanate compound, a polyol compound, or a bis-azide compound.
6. The method of claim 4 , wherein the cross-linking agent is expressed by Chemical Formula 3:
7. The method of claim 1 , wherein the alignment solution comprises the cross-linking agent in an amount of 0.1 wt % to 7 wt % based on 100 wt % of the alignment solution.
8. The method of claim 1 , wherein the second temperature is higher than the cross-linking reaction temperature.
9. The method of claim 1 , wherein the curing of the alignment solution comprises:
pre-curing the alignment solution at a third temperature; and
main curing the alignment solution at a fourth temperature that is higher than the third temperature.
10. The method of claim 9 , wherein the main curing is performed for a longer period of time than the pre-curing.
11. The method of claim 10 , wherein the third temperature is in a range of 65° C. to 80° C. and the fourth temperature is in a range of 50° C. to 200° C., and
the pre-curing is performed for 60 seconds to 300 seconds and the main curing is performed for 600 seconds to 1,000 seconds.
12. The method of claim 10 , wherein the baking is performed for a longer period of time than the main curing.
13. The method of claim 12 , wherein the second temperature is in a range of 210° C. to 240° C., and the baking is performed for 1,200 seconds to 2,500 seconds.
14. The method of claim 1 , wherein the light comprises ultraviolet light, infrared light, or far infrared light.
15. The method of claim 14 , wherein the light is partially polarized or fully polarized light.
16. A method of forming an alignment layer of a liquid crystal display, comprising:
forming an alignment solution on a base substrate;
curing the alignment solution at a first temperature to form an alignment layer;
exposing the base substrate to light or an electron beam to align the alignment layer; and
baking the alignment layer at a second temperature,
wherein the first temperature is lower than a cross-linking reaction temperature of the alignment solution, and
wherein the cross linking agent is expressed by Chemical Formula 3:
17. The method of forming an alignment layer of a liquid crystal display of claim 16 , wherein curing the alignment solution comprising pre-curing the alignment solution and main curing the alignment solution.
18. The method of forming an alignment layer of a liquid crystal display of claim 17 , wherein the temperature of the pre-curing and the main curing is 190° C.
19. The method of forming an alignment layer of a liquid crystal display of claim 16 , wherein the second temperature is higher than the cross-linking temperature.
20. The method of forming an alignment layer of a liquid crystal display of claim 16 , wherein the second temperature is in a range of 210° C. to 240° C.