Vertical alignment liquid crystal display and manufacture method thereof

Abstract

A vertical alignment liquid crystal display includes a first substrate, a second substrate, a liquid crystal layer located between the first substrate and the second substrate, a first and a second passivation layers respectively located at inner sides of the first and the second substrates, a common electrode layer and a pixel electrode layer respectively located on the first and the second passivation layers. The liquid crystal layer includes liquid crystal molecules, auxiliary alignment agent and a polymer network penetrating the entire liquid crystal layer. The auxiliary alignment agent makes the liquid crystal molecules in the liquid crystal layer vertically aligned on the surfaces of the first and the second substrates. The polymer network stabilizes alignment of the liquid crystal molecules and enhances vertical alignment effect of the auxiliary alignment agent to the liquid crystal molecules.

Claims

1. A vertical alignment liquid crystal display, comprising a first substrate, a second substrate oppositely located with the first substrate, a liquid crystal layer located between the first substrate and the second substrate, a first passivation layer and a second passivation layer respectively located at inner sides of the first substrate and the second substrate, and a common electrode layer and a pixel electrode layer respectively located on the first passivation layer and the second passivation layer; wherein the liquid crystal layer comprises liquid crystal molecules, an auxiliary alignment agent and a polymer network penetrating the entire liquid crystal layer; the auxiliary alignment agent makes the liquid crystal molecules in the liquid crystal layer vertically aligned on the first substrate and the second substrate; the polymer network stabilizes alignment of the liquid crystal molecules and enhances the vertical alignment effect of the auxiliary alignment agent on the liquid crystal molecules; wherein the polymer network is formed through polymerization of polymeric monomers, each of the polymeric monomers having at least two polymerizable groups; wherein the polymeric monomers comprise at least one double polymerizable group monomer having two polymerizable groups and at least one polymeric group compound having at least three polymerizable groups; and a weight percentage of the polymeric group compound in the polymeric monomers is 10%-50%; and wherein a constitutional formula of the double polymerizable group monomer is: ##STR00013## wherein P1 and P2 are polymerizable groups, which are the same or different and are each selected as one of methylacrylate, acrylate, epoxy group, and vinyl, n1 and n2 are integers between 0 and 5 and are the same or different, A1 and A2 are hexatomic rings, which are the same or different, each comprising or not comprising a substituent group, and which are each a benzene ring or cyclohexane, and X is a linking group, which is one of alkyl, ether, and ester groups of chains that have a main chain containing 1-20 molecules which are substituted or unsubstituted, or a hexatomic ring which contains 1-5 of directly linked or spaced alkyl, ether, and ester groups of chains which are substituted or unsubstituted; wherein a constitutional formula of the polymeric group compound is: ##STR00014## wherein Y is a kernel atom or group linking with a plurality of substituent groups, and which is one of a carbon atom, a nitride atom, a phosphate radical, and a multi ring group which is substituted or unsubstituted, L is a linking group, which is one of alkyl, ether, and ester groups of chains that have a main chain containing 1-20 molecules which are substituted or unsubstituted; P is a polymerizable group, which is selected as one of methylacrylate, acrylate, epoxy group, and vinyl, and n is 3 or 4.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The technical solution and the beneficial effects of the present invention are best understood from the following detailed description with reference to the accompanying figures and embodiments.

(2) In drawings,

(3) FIG. 1 is a sectional view of a vertical alignment liquid crystal display using alignment layers according to prior art;

(4) FIG. 2 is a top view of one side of a lower substrate in an MVA liquid crystal display using alignment layers according to prior art;

(5) FIG. 3 is a sectional view of an MVA liquid crystal display using alignment layers according to prior art;

(6) FIG. 4 is a sectional view of a vertical alignment liquid crystal display using auxiliary alignment agent according to prior art;

(7) FIG. 5 is a sectional structure view of the vertical alignment liquid crystal display according to the present invention;

(8) FIG. 6 is a flowchart of a manufacture method of the vertical alignment liquid crystal display according to the present invention;

(9) FIG. 7 is a view showing step 1 of the manufacture method of the vertical alignment liquid crystal display according to the present invention;

(10) FIG. 8 is a view showing step 3 of the manufacture method of the vertical alignment liquid crystal display according to the present invention;

(11) FIGS. 9 and 10 are views showing step 5 of the manufacture method of the vertical alignment liquid crystal display according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(12) For better explaining the technical solution and the effect of the present invention, the present invention will be further described in detail with the accompanying drawings and the specific embodiments.

(13) Referring to FIG. 5, the present invention first provides a vertical alignment liquid crystal display, comprising a first substrate 1, a second substrate 2, oppositely located with the first substrate 1, a liquid crystal layer 3 located between the first substrate 1 and the second substrate 2, a first passivation layer 11 and a second passivation layer 21 respectively located at inner sides of the first substrate 1 and the second substrate 2 and a common electrode layer 12 and a pixel electrode layer 22 respectively located on the first passivation layer 11 and the second passivation layer 21.

(14) The first substrate 1 comprises a black matrix, a color filter and photo spacers but not limited thereto. The first substrate 1 is equivalent to a CF substrate of the traditional liquid crystal display. The second substrate 2 comprises gate lines, scan lines, thin film transistors but not limited thereto. The second substrate 2 is equivalent to a TFT substrate of the traditional liquid crystal display. Materials of the common electrode layer 12 and the pixel electrode layer 22 are both ITO. A material of the first passivation layer 11 and a material of the second passivation layer 21 are silicon nitride.

(15) The liquid crystal layer 3 comprises liquid crystal molecules 30, auxiliary alignment agent 31 and a polymer network 33 penetrating the entire liquid crystal layer 3 but not limited thereto. Furthermore, the liquid crystal molecules 30 are negative liquid crystal molecules. The vertical alignment liquid crystal display of the present invention does not use the PI alignment layer but the auxiliary alignment agent 31 in the liquid crystal layer 3 for achieving the vertical alignment of the liquid crystal molecules 30, to make the liquid crystal molecules 30 vertically aligned on the surfaces of the first and the second substrates 1, 2, and save consumption of the PI material and the investments for the related equipments of PI spray coating, baking. The tremendous consumed energy required in the PI pre-baking and high temperature post baking processes can be saved to prevent the damages to the environment and human body from the solvent evaporation in the PI processes.

(16) The polymer network 33 has an extremely large surface area, and an extremely large contact area with the liquid crystal molecules 30 to stabilize alignment of the liquid crystal molecules 30 and enhance vertical alignment effect of the auxiliary alignment agent 31 to the liquid crystal molecules 30.

(17) The polymer network 33 is manufactured by polymerization of UV light sensitive polymeric monomer after UV irradiation. A weight percentage of the polymeric monomer 32 in the liquid crystal layer 3 is 0.5%-8%, and preferably, the weight percentage of the polymeric monomer 32 in the liquid crystal layer 3 is 1%-5%. Specifically, the polymeric monomer comprises two or more compounds of methylacrylate, acrylate, epoxy group, vinyl, which comprises at least one double polymerizable group monomer and at least one polymeric group compound. A weight percentage of the polymeric group compound in the polymerizable monomer is 10%-50%.

(18) The double polymerizable group monomer comprises two polymerizable groups, and the polymerizable group can be methylacrylate, acrylate, epoxy group or vinyl. The polymeric group compound comprises three or more polymerizable groups, and the polymerizable group can be methylacrylate, acrylate or epoxy group. The polymeric group compound comprises a plurality of polymerizable groups which can act as a crosslinking center in the polymerization for easily forming the polymer network 33.

(19) Specifically, the double polymerizable group monomer comprises a constitutional formula of:

(20) ##STR00005##

(21) wherein P1 and P2 are polymeric groups, and the two can be the same or different and are selected as one of methylacrylate, acrylate, epoxy group, vinyl.

(22) n1 and n2 are integers of 0-5, and the two can be the same or different.

(23) A1 and A2 are hexatomic rings, and the two can be the same or different, and comprise substituent group or do not comprise substituent group, and can be benzene rings or cyclohexane.

(24) X is linking group, which can be alkyl, ether, ester group chain that main chain contains 1-20 molecules replaced or not replaced, or hexatomic ring, which contains 1-5 of directly linked or spaced alkyl, ether, ester group of chain replaced or not replaced.

(25) For instance, a constitutional formula of the double polymerizable group monomer can be:

(26) ##STR00006##

(27) The polymeric group compound comprises a constitutional formula of:

(28) ##STR00007##

(29) wherein Y is kernel atom or group, capable of linking a plurality of substituent groups, and L is linking group, and P is polymeric group, and n is 3 or 4.

(30) Y can be carbon atom, nitride atom, phosphate radical, multi ring group replaced or not replaced; L is alkyl, ether, ester group chain that main chain contains 1-20 molecules replaced or not replaced; P is selected from one of methylacrylate, acrylate, epoxy group, vinyl.

(31) For instance, a specific constitutional formula of the polymeric group compound can be:

(32) ##STR00008##

(33) Referring to FIGS. 6-10, the present invention further provides a manufacture method of the vertical alignment liquid crystal display, comprising steps of:

(34) step 1, loading a first substrate 1 and a second substrate 2.

(35) As shown in FIG. 7, a first passivation layer 11 and a second passivation layer 21 are respectively located at inner sides of the first substrate 1 and the second substrate 2, and a common electrode layer 12 and a pixel electrode layer 22 are respectively located on the first passivation layer 11 and the second passivation layer 21.

(36) The first substrate 1 comprises a black matrix, a color filter and photo spacers but not limited thereto. The first substrate 1 is equivalent to a CF substrate of the traditional liquid crystal display. The second substrate 2 comprises gate lines, scan lines, thin film transistors but not limited thereto. The second substrate 2 is equivalent to a TFT substrate of the traditional liquid crystal display. Materials of the common electrode layer 12 and the pixel electrode layer 22 are both ITO. A material of the first passivation layer 11 and a material of the second passivation layer 21 are silicon nitride.

(37) step 2, coating a glue frame on the first substrate 1 or the second substrate 2.

(38) step 3, filling a liquid crystal layer 3 in a district surrounded by the glue frame.

(39) As shown in FIG. 8, the liquid crystal layer 3 comprises liquid crystal molecules 30, auxiliary alignment agent 31 and polymeric monomer 32 penetrating the entire liquid crystal layer 3 but not limited thereto. The liquid crystal molecules 30 are negative liquid crystal molecules.

(40) A weight percentage of the polymeric monomer 32 in the liquid crystal layer 3 is 0.5%-8%, and preferably, the weight percentage of the polymeric monomer 32 in the liquid crystal layer 3 is 1%-5%. Specifically, the polymeric monomer comprises two or more compounds of methylacrylate, acrylate, epoxy group, vinyl, which comprises at least one double polymerizable group monomer and at least one polymeric group compound. A weight percentage of the polymeric group compound in the polymerizable monomer is 10%-50%.

(41) The double polymerizable group monomer comprises two polymerizable groups, and the polymerizable group can be methylacrylate, acrylate, epoxy group or vinyl. The polymeric group compound comprises three or more polymerizable groups, and the polymerizable group can be methylacrylate, acrylate or epoxy group. The polymeric group compound comprises a plurality of polymerizable groups which can act as a crosslinking center in the polymerization for easily forming the polymer network 33.

(42) Specifically, the double polymerizable group monomer comprises a constitutional formula of:

(43) ##STR00009##

(44) wherein P1 and P2 are polymeric groups, and the two can be the same or different, and selected from one of methylacrylate, acrylate, epoxy group, vinyl.

(45) n1 and n2 are integers of 0-5, and the two can be the same or different.

(46) A1 and A2 are hexatomic rings, and the two can be the same or different, and comprise substituent group or do not comprise substituent group, and can be benzene rings or cyclohexane.

(47) X is linking group, which can be alkyl, ether, ester group chain that main chain contains 1-20 molecules replaced or not replaced, or hexatomic ring, which contains 1-5 of directly linked or spaced alkyl, ether, ester group of chain replaced or not replaced.

(48) For instance, a constitutional formula of the double polymerizable group monomer can be:

(49) ##STR00010##

(50) The polymeric group compound comprises a constitutional formula of:

(51) ##STR00011##

(52) wherein Y is kernel atom or group, capable of linking a plurality of substituent groups, and L is linking group, and P is polymeric group, and n is 3 or 4.

(53) Y can be carbon atom, nitride atom, phosphate radical, multi ring group replaced or not replaced; L is alkyl, ether, ester group chain that main chain contains 1-20 molecules replaced or not replaced; P is selected from one of methylacrylate, acrylate, epoxy group, vinyl.

(54) For instance, a specific constitutional formula of the polymeric group compound can be:

(55) ##STR00012##

(56) step 4, assembling the first substrate 1 and the second substrate 2.

(57) step 5, as shown in FIG. 9, applying voltage to the common electrode layer 12 and the pixel electrode layer 22 to make the liquid crystal molecules 30 in the liquid crystal layer 3 twisted with a certain degree, and employing UV to irradiate the liquid crystal layer 3.

(58) As shown in FIG. 10, the polymeric monomer 32 is occurred with polymerization to form a polymer network 33 penetrating the entire liquid crystal layer 3. The polymer network 33 has an extremely large surface area, and an extremely large contact areas with the liquid crystal molecules 30 to stabilize alignment of the liquid crystal molecules 30 and enhance vertical alignment effect of the auxiliary alignment agent 31 to the liquid crystal molecules 30.

(59) Besides, in the manufacture method vertical alignment liquid crystal display of the present invention the PI alignment layer is not manufactured and saves consumption of the PI material and the investments for the related equipments of PI spray coating, baking. The tremendous consumed energy required in the PI pre-baking and high temperature post baking processes can be saved to prevent the damages to the environment and human body from the solvent evaporation in the PI processes.

(60) In conclusion, in the vertical alignment liquid crystal display of the present invention, the liquid crystal layer comprises liquid crystal molecules, auxiliary alignment agent and a polymer network penetrating the entire liquid crystal layer, and with the auxiliary alignment agent, the vertical alignment of the liquid crystal molecules can be achieved. The polymer network has an extremely large surface area, and an extremely large contact area with the liquid crystal molecules to stabilize alignment of the liquid crystal molecules and enhance vertical alignment effect of the auxiliary alignment agent to the liquid crystal molecules. Thus, the weaker alignment ability issue of the small molecule auxiliary alignment agent can be solved to enhance the aligning force and the anchoring energy of the auxiliary alignment agent to the liquid crystal molecules and vertical alignment effect of the auxiliary alignment agent to the liquid crystal molecules; in the manufacture method of the vertical alignment liquid crystal display according to the present invention, by filling the liquid crystal layer comprising liquid crystal molecules, auxiliary alignment agent and polymeric monomer, and applying voltage to the liquid crystal layer with UV irradiation to induce polymerization of polymeric monomer, a polymer network penetrating the entire liquid crystal layer with a extremely large surface area is formed. The polymer network has an extremely large surface area, and an extremely large contact area with the liquid crystal molecules to stabilize alignment of the liquid crystal molecules. Thus, the weaker alignment ability issue of the small molecule auxiliary alignment agent can be solved to enhance the aligning force and the anchoring energy of the auxiliary alignment agent to the liquid crystal molecules and vertical alignment effect of the auxiliary alignment agent to the liquid crystal molecules. The method is more environmental protective and saves energy.

(61) Above are only specific embodiments of the present invention, the scope of the present invention is not limited to this, and to any persons who are skilled in the art, change or replacement which is easily derived should be covered by the protected scope of the invention. Thus, the protected scope of the invention should go by the subject claims.