Liquid crystal material, liquid crystal display panel, and method for manufacturing the liquid crystal display panel

Abstract

A liquid crystal material for a liquid crystal display panel is used to form a polymer film on a substrate on which no PI layer is provided so as to realize normal display of the liquid crystal panel. Meanwhile, realiability of the panel can be improved, a voltage holding rate can be improved, and poor alignment of the self-alignment liquid crystal material, afterimage, and other problems can be solved.

Claims

1. A liquid crystal material, comprising liquid crystal molecules, a vertical alignment agent, and a polymerizable monomer, wherein the vertical alignment agent comprises one compound or more compounds selected from a group consisting of: ##STR00027##

2. The liquid crystal material according to claim 1, wherein the polymerizable monomer comprises one or more selected from a group consisting of acrylate and derivatives thereof, methacrylate and derivatives thereof, styrene and derivatives thereof, epoxy resin, and a fatty amine epoxy curing agent.

3. The liquid crystal material according to claim 1, wherein the polymerizable monomer comprises one or two selected from: ##STR00028##

4. The liquid crystal material according to claim 1, wherein the liquid crystal material comprises 94 wt % to 99.8 wt % of the liquid crystal molecules, 0.1 wt % to 5 wt % of the vertical alignment agent, and 0.1 wt % to 1 wt % of the polymerizable monomer.

5. A liquid crystal display panel, comprising: a first substrate, on which an alignment film is arranged; a second substrate, on which a polymer film is arranged, wherein the second substrate is not provided with an alignment film, and the polymer film is formed by a vertical alignment agent and a polymerizable monomer after polymerization reaction; and a liquid crystal layer, which is arranged between the first substrate and the second substrate, wherein the liquid crystal layer comprises liquid crystal molecules; wherein the vertical alignment agent comprises one compound or more compounds selected from a group consisting of: ##STR00029##

6. The liquid crystal display panel according to claim 5, wherein the alignment film is a polyimide film with a thickness in a range from 30 nm to 120 nm.

7. The liquid crystal display panel according to claim 5, wherein the first substrate is a TFT substrate, and the second substrate is a color filter substrate.

8. The liquid crystal display panel according to claim 5, wherein the first substrate is a color filter substrate, and the second substrate is a TFT substrate.

9. The liquid crystal display panel according to claim 5, wherein the polymerizable monomer comprises one or more selected from a group consisting of acrylate and derivatives thereof, methacrylate and derivatives thereof, styrene and derivatives thereof, epoxy resin, and a fatty amine epoxy curing agent.

10. The liquid crystal display panel according to claim 5, wherein the polymerizable monomer comprises one or two selected from: ##STR00030##

11. A method for manufacturing a liquid crystal display panel, comprising steps of: step 1, providing a first substrate, a second substrate, and a liquid crystal material respectively, wherein the first substrate is provided with an alignment film, and the second substrate is not provided with an alignment film; step 2, dropwise adding the liquid crystal material on the second substrate, coating a sealant on a surface of the second substrate, and coating a conductive adhesive on a peripheral area of the second substrate; step 3, fitting the first substrate and the second substrate after treatment in step 2 together, and curing the sealant; step 4, applying a voltage to the liquid crystal material that is dropwise added on the second substrate so that liquid crystal molecules deflect, and irradiating the liquid crystal material with ultraviolet for a first time, so that a vertical alignment agent and a polymerizable monomer experience polymerization reaction, wherein a polymer produced by the polymerization reaction is deposited on a surface of the second substrate facing the liquid crystal material to form a polymer film; and step 5, cutting off the voltage, and irradiating the liquid crystal material, which has been irradiated by ultraviolet for the first time, with ultraviolet for a second time, so that residual vertical alignment agent and polymerizable monomer in the liquid crystal material experience polymerization reaction, wherein a polymer produced by the polymerization reaction is deposited on the polymer film formed in step 4; wherein the vertical alignment agent comprises one compound or more compounds selected from a group consisting of: ##STR00031## wherein the polymerizable monomer comprises one or more selected from a group consisting of acrylate and derivatives thereof, methacrylate and derivatives thereof, styrene and derivatives thereof, epoxy resin, and a fatty amine epoxy curing agent.

12. The method according to claim 11, wherein in step 4, the voltage applied to the liquid crystal material is in a range from 13 V to 25 V.

13. The method according to claim 11, wherein in step 4, an energy of the ultraviolet used during ultraviolet irradiation for the first time ranges from 85 mW/cm.sup.2 to 100 mW/cm.sup.2, and an irradiation time ranges from 40 s to 100 s.

14. The method according to claim 11, wherein in step 5, an energy of the ultraviolet used during ultraviolet irradiation for the second time ranges from 85 mW/cm.sup.2 to 100 mW/cm.sup.2, and an irradiation time ranges from 90 min to 180 min.

15. The method according to claim 11, wherein in step 1, the alignment film is a polyimide film with a thickness in a range from 30 nm to 120 nm.

16. The method according to claim 11, wherein in step 1, the first substrate is a TFT substrate, and the second substrate is a color filter substrate.

17. The method according to claim 11, wherein in step 1, the first substrate is a color filter substrate, and the second substrate is a TFT substrate.

18. The method according to claim 11, wherein a thickness of the polymer film finally obtained in step 5 is in a range from 300 to 1200 .

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings provide further understandings of the present disclosure and constitute one part of the description. The drawings are used for interpreting the present disclosure together with the embodiments, not for limiting the present disclosure. In the drawings:

(2) FIG. 1 schematically shows an embodiment of a method for manufacturing a liquid crystal display panel according to the present disclosure; and

(3) FIG. 2 schematically shows another embodiment of a method for manufacturing a liquid crystal display panel according to the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(4) The present disclosure will be illustrated in detail hereinafter with reference to the embodiments. However, the present disclosure is not limited by the embodiments disclosed herein.

Embodiment 1

(5) A TFT substrate, a color filter substrate, and a self-alignment liquid crystal material are provided, wherein the TFT substrate is provided with a PI film with a thickness of 100 nm, and the color filter substrate is not provided with a PI film. In the self-alignment liquid crystal material, a ratio of the vertical alignment agent, the polymerizable monomer, to the liquid crystal molecules is 0.5 wt %:0.3 wt %:99.2 wt %.

(6) The vertical alignment agent has a structure of:

(7) ##STR00019##

(8) The polymerizable monomer has a structure of:

(9) ##STR00020##

(10) The liquid crystal material is dropwise added on the color filter substrate. A sealant is coated on a surface of the color filter substrate, and a conductive adhesive is coated on a peripheral area of the color filter substrate.

(11) Then, in a vacuum environment, the TFT substrate and the treated color filter substrate are fitted together, and the sealant is cured by a heat curing method or UV curing method.

(12) Next, a 13-25 V voltage is applied to the liquid crystal material that is dropwise added on the color filter substrate so that liquid crystal molecules can deflect. The liquid crystal material is irradiated by ultraviolet for a first time, so that the vertical alignment agent and the polymerizable monomer experience polymerization reaction. An energy of the ultraviolet used during ultraviolet irradiation for the first time ranges from 85 mW/cm.sup.2 to 100 mW/cm.sup.2, and an irradiation time ranges from 40 s to 100 s. A polymer produced by the polymerization reaction is deposited on a surface of the color filter substrate facing the liquid crystal material to form a polymer film.

(13) At last, the voltage is cut off. The liquid crystal material is irradiated by ultraviolet for a second time, so that residual vertical alignment agent and polymerizable monomer in the liquid crystal material experience polymerization reaction. An energy of the ultraviolet used during ultraviolet irradiation for the second time ranges from 85 mW/cm.sup.2 to 100 mW/cm.sup.2, and an irradiation time ranges from 90 min to 180 min. A polymer produced by the polymerization reaction is deposited on the polymer film formed in a previous step. A thickness of the polymer film finally obtained is about 600 .

(14) The liquid crystal material, in which the vertical alignment agent and the polymerizable monomer are removed, constitutes a liquid crystal layer, and thus a liquid crystal display panel is obtained.

Embodiment 2

(15) A TFT substrate, a color filter substrate, and a self-alignment liquid crystal material are provided, wherein the TFT substrate is provided with a PI film with a thickness of 100 nm, and the color filter substrate is not provided with a PI film. In the self-alignment liquid crystal material, a ratio of the vertical alignment agent, the polymerizable monomer, to the liquid crystal molecules is 1.5 wt %:0.3 wt %:98.2 wt %.

(16) The vertical alignment agent has a structure of:

(17) ##STR00021##

(18) The polymerizable monomer has a structure of:

(19) ##STR00022##

(20) The liquid crystal material is dropwise added on the color filter substrate. A sealant is coated on a surface of the color filter substrate, and a conductive adhesive is coated on a peripheral area of the color filter substrate.

(21) Then, in a vacuum environment, the TFT substrate and the treated color filter substrate are fitted together, and the sealant is cured by a heat curing method or UV curing method.

(22) Next, a 13-25 V voltage is applied to the liquid crystal material that is dropwise added on the color filter substrate so that liquid crystal molecules can deflect. The liquid crystal material is irradiated by ultraviolet for a first time, so that the vertical alignment agent and the polymerizable monomer experience polymerization reaction. An energy of the ultraviolet used during ultraviolet irradiation for the first time ranges from 85 mW/cm.sup.2 to 100 mW/cm.sup.2, and an irradiation time ranges from 40 s to 100 s. A polymer produced by the polymerization reaction is deposited on a surface of the color filter substrate facing the liquid crystal material to form a polymer film.

(23) At last, the voltage is cut off. The liquid crystal material is irradiated by ultraviolet for a second time, so that residual vertical alignment agent and polymerizable monomer in the liquid crystal material experience polymerization reaction. An energy of the ultraviolet used during ultraviolet irradiation for the second time ranges from 85 mW/cm.sup.2 to 100 mW/cm.sup.2, and an irradiation time ranges from 90 min to 180 min. A polymer produced by the polymerization reaction is deposited on the polymer film formed in a previous step. A thickness of the polymer film finally obtained is about 800 .

(24) The liquid crystal material, in which the vertical alignment agent and the polymerizable monomer are removed, constitutes a liquid crystal layer, and thus a liquid crystal display panel is obtained.

Embodiment 3

(25) A TFT substrate, a color filter substrate, and a self-alignment liquid crystal material are provided, wherein the TFT substrate is not provided with a PI film, and the color filter substrate is provided with a PI film with a thickness of 100 nm. In the self-alignment liquid crystal material, a ratio of the vertical alignment agent, the polymerizable monomer, to the liquid crystal molecules is 0.5 wt %:0.3 wt %:99.2 wt %.

(26) The vertical alignment agent has a structure of:

(27) ##STR00023##

(28) The polymerizable monomer has a structure of:

(29) ##STR00024##

(30) The liquid crystal material is dropwise added on the TFT substrate. A sealant is coated on a surface of the TFT substrate, and a conductive adhesive is coated on a peripheral area of the TFT substrate.

(31) Then, in a vacuum environment, the color filter substrate and the treated TFT substrate are fitted together, and the sealant is cured by a heat curing method or UV curing method.

(32) Next, a 13-25 V voltage is applied to the liquid crystal material so that liquid crystal molecules can deflect. The liquid crystal material is irradiated by ultraviolet for a first time, so that the vertical alignment agent and the polymerizable monomer experience polymerization reaction. An energy of the ultraviolet used during ultraviolet irradiation for the first time ranges from 85 mW/cm.sup.2 to 100 mW/cm.sup.2, and an irradiation time ranges from 40 s to 100 s. A polymer produced by the polymerization reaction is deposited on a surface of the TFT substrate facing the liquid crystal material to form a polymer film.

(33) At last, the voltage is cut off. The liquid crystal material is irradiated by ultraviolet for a second time, so that residual vertical alignment agent and polymerizable monomer in the liquid crystal material experience polymerization reaction. An energy of the ultraviolet used during ultraviolet irradiation for the second time ranges from 85 mW/cm.sup.2 to 100 mW/cm.sup.2, and an irradiation time ranges from 90 min to 180 min. A polymer produced by the polymerization reaction is deposited on the polymer film formed in a previous step. A thickness of the polymer film finally obtained is about 1100 .

(34) The liquid crystal material, in which the vertical alignment agent and the polymerizable monomer are removed, constitutes a liquid crystal layer, and thus a liquid crystal display panel is obtained.

Comparative Embodiment 1

(35) A TFT substrate, a color filter substrate, and a self-alignment liquid crystal material are provided, wherein the TFT substrate and the color filter substrate both are not provided with a PI film. In the self-alignment liquid crystal material, a ratio of the vertical alignment agent, the polymerizable monomer, to the liquid crystal molecules is 0.5 wt %:0.3 wt %:99.2 wt %.

(36) The vertical alignment agent has a structure of:

(37) ##STR00025##

(38) The polymerizable monomer has a structure of:

(39) ##STR00026##

(40) The liquid crystal material is dropwise added on the TFT substrate and the color filter substrate. A sealant is coated on a surface of the TFT substrate and the color filter substrate, and a conductive adhesive is coated on a peripheral area of the TFT substrate and the color filter substrate.

(41) Then, in a vacuum environment, the treated color filter substrate and TFT substrate are fitted together, and the sealant is cured by a heat curing method or UV curing method.

(42) Next, a 13-25 V voltage is applied to the liquid crystal material so that liquid crystal molecules can deflect. The liquid crystal material is irradiated by ultraviolet for a first time, so that the vertical alignment agent and the polymerizable monomer experience polymerization reaction. An energy of the ultraviolet used during ultraviolet irradiation for the first time ranges from 85 mW/cm.sup.2 to 100 mW/cm.sup.2, and an irradiation time ranges from 40 s to 100 s. A polymer produced by the polymerization reaction is deposited on the TFT substrate and the color filter substrate to form a polymer film.

(43) At last, the voltage is cut off. The liquid crystal material is irradiated by ultraviolet for a second time, so that residual vertical alignment agent and polymerizable monomer in the liquid crystal material experience polymerization reaction. An energy of the ultraviolet used during ultraviolet irradiation for the second time ranges from 85 mW/cm.sup.2 to 100 mW/cm.sup.2, and an irradiation time ranges from 90 min to 180 min. A polymer produced by the polymerization reaction is deposited on the polymer film formed in a previous step. A thickness of the polymer film finally obtained is about 1100 .

(44) The liquid crystal material, in which the vertical alignment agent and the polymerizable monomer are removed, constitutes a liquid crystal layer, and thus a liquid crystal display panel is obtained.

(45) Table 1 shows performances of liquid crystal display panels manufactured by Embodiments 1 to 3 and Comparative Embodiment 1.

(46) TABLE-US-00001 TABLE 1 Voltage If there is holding rate light leakage (1 V, 60 C., If there is If there is in dark state 0.6 Hz) an afterimage a dark line Embodiment 1 No 98.2% No No Embodiment 2 No 98.0% No No Embodiment 3 No 99.2% No No Comparative Slight 97.5% Yes Yes Embodiment 1 light leakage

(47) It can be seen from Table 1 that, compared with Comparative Embodiment 1, in the liquid crystal display panels manufactured by Embodiments 1 to 3, a normal display can be realized, and a voltage holding rate can be improved. At the same time, poor alignment of the self-alignment liquid crystal material, afterimage and other problems can be solved.

(48) The embodiments disclosed herein are used for illustrating, rather than restricting, the present disclosure. Although the embodiments are disclosed hereinabove, it can be understood that, various deformations can be made by those skilled in the art without departing from the teachings and advantages of the present disclosure, and all deformations are included in the scope as defined by the claims. It can be understood that, the embodiments disclosed herein are descriptive and illustrative ones, rather than restrictive ones. The protection scope of the present disclosure shall be determined by the claims.