WO2020186569A1 - Liquid crystal material and liquid crystal display panel - Google Patents

Abstract

The present invention provides a liquid crystal material and a liquid crystal display panel. The liquid crystal material comprises a mixed liquid crystal matrix and a heat stabilizer, wherein the concentration of the heat stabilizer is greater than 50 PPM and is less than 3,000 PPM; by adding the heat stabilizer with the concentration being greater than 50 PPM and less than 3,000 PPM into the liquid crystal material, the density of the present liquid crystal material changes more slowly along with changes in temperature than does the liquid crystal material of the prior art; when the liquid crystal material is applied to the liquid crystal display panel, a change in a volume of the liquid crystal material in a liquid crystal box caused by a temperature change can be reduced, so that a liquid crystal quantity control range is improved, product defects are reduced, and the product quality is improved.

Description

Liquid crystal material and liquid crystal display panel Technical field

The present invention relates to the field of display technology, in particular to a liquid crystal material and a liquid crystal display panel.

Background technique

With the development of display technology, flat-panel display devices such as Liquid Crystal Display (LCD) have been widely used in mobile phones, TVs, and personal computers due to their advantages of high image quality, power saving, thin body and wide application range. Various consumer electronic products such as digital assistants, digital cameras, notebook computers, and desktop computers have become the mainstream of display devices.

Most of the liquid crystal display devices currently on the market are backlit liquid crystal displays, which include a liquid crystal display panel and a backlight module. The working principle of the liquid crystal display panel is to place liquid crystal molecules between two parallel glass substrates. There are many vertical and horizontal small wires between the two glass substrates. The liquid crystal molecules are controlled to change direction by powering on or not, and the light of the backlight module Refraction produces a picture.

Usually the liquid crystal display panel consists of a color film substrate (CF, Color Filter), a thin film transistor substrate (TFT, Thin Film Transistor), liquid crystal (LC, Liquid Crystal) and sealant (Sealant) sandwiched between the color film substrate and the thin film transistor substrate. The molding process generally includes: the front-end array (Array) process (film, yellow light, etching And peeling), the middle-stage cell process (the bonding of the TFT substrate and the CF substrate) and the back-end module assembly process (the pressing of the driver IC and the printed circuit board). Among them, the front Array process is mainly to form TFT substrates to control the movement of liquid crystal molecules; the middle Cell process is mainly to add liquid crystal between the TFT substrate and the CF substrate; the back module assembly process is mainly to drive IC pressing and printed circuits The integration of the board drives the rotation of the liquid crystal molecules to display images.

Under high temperature conditions, the thermal expansion of the liquid crystal in the liquid crystal display panel is significantly greater than that of other components, which causes the cell thickness of the liquid crystal cell assembly to increase, and other parts cannot thermally expand to a corresponding degree, which easily causes the liquid crystal in the vertically placed liquid crystal display panel due to gravity. The effect and the whole downward flow, resulting in uneven gravity display under high temperature (Gravity mura, G mura) defect, and in the low temperature state, the thermal shrinkage of the liquid crystal is greater than that of other parts, that is, the liquid crystal will not be able to fill the entire liquid crystal cell assembly and a vacuum occurs when the cell thickness of the liquid crystal cell is still maintained. Bubbles, producing low temperature bubbles (bubble) Defects. This defect limits the application conditions of the liquid crystal display device, affects the display effect of the liquid crystal display device, and thereby reduces the user experience. In the manufacturing process, the allowable liquid crystal volume control range without occurrence of uneven gravity display defects at high temperatures and bubble defects at low temperatures is called LC Margin (Liquid Crystal Margin).

technical problem

The purpose of the present invention is to provide a liquid crystal material, which can increase the control range of the amount of liquid crystal, reduce product defects, and improve product quality.

The purpose of the present invention is also to provide a liquid crystal display panel, which can increase the control range of liquid crystal volume, reduce product defects, and improve product quality.

Technical solutions

In order to achieve the above objective, the present invention provides a liquid crystal material comprising a mixed liquid crystal matrix and a thermal stabilizer, the concentration of the thermal stabilizer is greater than 50 PPM and less than 3000 PPM.

The heat stabilizer is a hindered phenolic material.

In the temperature range of -20°C to 60°C, the curvature range of the density of the liquid crystal material with temperature changes is -0.08% to 0;

Wherein, the formula for calculating the curvature of the density of the liquid crystal material with temperature is: R=(AB)/80, R is the curvature of the density of the liquid crystal material with temperature, A is the density of the liquid crystal material at 60°C, B Is the density of the liquid crystal material at -20°C, A is less than B.

The liquid crystal material also includes at least one reactive monomer.

The structure of the reactive monomer is a first group connected with at least one acrylate group, and the first group is a group formed by directly or indirectly connecting 2 to 4 benzene rings or a naphthalene ring.

The present invention also provides a liquid crystal display panel, which includes an upper substrate and a lower substrate which are arranged oppositely, and a liquid crystal layer arranged between the upper substrate and the lower substrate;

The liquid crystal material used in the liquid crystal layer includes a mixed liquid crystal matrix and a thermal stabilizer, and the concentration of the thermal stabilizer is greater than 50 PPM and less than 3000 PPM.

The heat stabilizer is a hindered phenolic material.

In the temperature range of -20°C to 60°C, the curvature range of the density of the liquid crystal material with temperature changes is -0.08% to 0;

Wherein, the formula for calculating the curvature of the density of the liquid crystal material with temperature is: R=(AB)/80, R is the curvature of the density of the liquid crystal material with temperature, A is the density of the liquid crystal material at 60°C, B Is the density of the liquid crystal material at -20°C, A is less than B.

The liquid crystal display panel further includes at least one reactive monomer.

The structure of the reactive monomer is a first group connected with at least one acrylate group, and the first group is a group formed by directly or indirectly connecting 2 to 4 benzene rings or a naphthalene ring.

Beneficial effect

The beneficial effects of the present invention: the present invention provides a liquid crystal material, including a mixed liquid crystal matrix and a thermal stabilizer, the concentration of the thermal stabilizer is greater than 50PPM and less than 3000PPM, by adding a concentration greater than 50PPM and less than 3000PPM to the liquid crystal material The thermal stabilizer can make the density of the liquid crystal material change with temperature at a slower rate than the density of the existing liquid crystal material. The application of the liquid crystal material to the liquid crystal display panel can reduce the temperature change. The volume change of the liquid crystal material in the liquid crystal cell increases the control range of the liquid crystal volume, reduces product defects, and improves product quality. The invention provides a liquid crystal display panel, which can increase the control range of liquid crystal quantity, reduce product defects and improve product quality.

Description of the drawings

In order to further understand the features and technical content of the present invention, please refer to the following detailed description and accompanying drawings of the present invention. However, the accompanying drawings are only provided for reference and illustration and are not used to limit the present invention.

In the attached picture,

FIG. 1 is a schematic diagram of a liquid crystal display panel of the present invention;

2 is a schematic diagram of the comparison between the density curve of the liquid crystal material of the present invention and the temperature curve of the existing liquid crystal material.

Embodiments of the invention

In order to further explain the technical means adopted by the present invention and its effects, the following describes in detail the preferred embodiments of the present invention and the accompanying drawings.

Please refer to the figure 1 , The present invention provides a liquid crystal material, including a mixed liquid crystal matrix and a thermal stabilizer;

Specifically, the liquid crystal matrix and the heat stabilizer are mixed to form a solution, and the concentration of the heat stabilizer in the solution is greater than 50PPM And less than 3000PPM .

Preferably, the thermal stabilizer is a hindered phenolic material, and the liquid crystal matrix is a negative liquid crystal.

It should be noted that the liquid crystal matrix and the thermal stabilizer are both dissolved in the solvent to form a solution. The thermal stabilizer is added to the liquid crystal material and the concentration of the thermal stabilizer is controlled to be greater than 50PPM And less than 3000PPM , Which can make the density of the liquid crystal material change with temperature at a slower speed than that of the existing liquid crystal material, thereby reducing the change in the volume of the liquid crystal material in the liquid crystal cell caused by the temperature change and improving LC Margin , Avoid low temperature bubble And high temperature G mura , Reduce product defects and improve product quality.

As shown 2 As shown in the figure 2 Middle curve A1 Is the curve of the density of the liquid crystal material of the present invention with temperature, and the curve B1 Is the density curve of the existing liquid crystal material with temperature, in -20 °C ~60 Within the temperature range of ℃, the density of the liquid crystal material of the present invention varies with temperature and the curvature range is -0.08%~0 , According to the picture 2 It can be seen that, compared with the prior art, the density of the liquid crystal material of the present invention changes with temperature at a slower speed than the prior art, so the liquid crystal material of the present invention has a smaller volume change due to temperature changes than the prior art.

It should be noted that the calculation formula for the curvature of the density of the liquid crystal material as a function of temperature is: R=(A-B)/(60-(-20))= (A-B)/80 , R Is the curvature of the density of the liquid crystal material with temperature, A For liquid crystal materials in 60 Density at ℃, B For liquid crystal materials in -20 Density at ℃, A Less than B .

Further, in some embodiments of the present invention, the liquid crystal material is a photoreactive liquid crystal material, which further includes at least one reactive monomer.

Specifically, the structure of the reactive monomer is a first group with at least one acrylate group attached, and the first group is 2~4 A group formed by directly or indirectly connecting a benzene ring or a naphthalene ring; wherein, the 2~4 The indirect connection of a benzene ring specifically refers to 2~4 Each benzene ring is connected indirectly through a group.

Further, the at least one acrylate is directly connected to the first group, and the first group may be further connected to other polymerizable groups besides the acrylate, that is, the reaction The structure of the sexual monomer is formed by directly connecting at least one polymerizable group to the first group, and at least one of the at least one polymerizable group is an acrylate group.

Please refer to the figure 1 Based on the above-mentioned liquid crystal material, the present invention also provides a liquid crystal display panel, which includes oppositely arranged upper substrates 1 And lower substrate 2 And on the upper substrate 1 And lower substrate 2 Liquid crystal layer 3 ；

The liquid crystal layer 3 The liquid crystal materials used include mixed liquid crystal matrix and thermal stabilizer;

Wherein, the liquid crystal matrix and the heat stabilizer are mixed to form a solution, and the concentration of the heat stabilizer in the solution is greater than 50PPM And less than 3000PPM .

Preferably, the thermal stabilizer is a hindered phenolic material, and the liquid crystal matrix is a negative liquid crystal.

It should be noted that the liquid crystal matrix and the thermal stabilizer are both dissolved in the solvent to form a solution. The thermal stabilizer is added to the liquid crystal material and the concentration of the thermal stabilizer is controlled to be greater than 50PPM And less than 3000PPM , Which can make the density of the liquid crystal material change with temperature at a slower speed than that of the existing liquid crystal material, thereby reducing the change in the volume of the liquid crystal material in the liquid crystal cell caused by the temperature change and improving LC Margin , Avoid low temperature bubble And high temperature G mura , Reduce product defects and improve product quality.

As shown 2 As shown in the figure 2 Middle curve A1 Is the curve of the density of the liquid crystal material of the present invention with temperature, and the curve B1 Is the density curve of the existing liquid crystal material with temperature, in -20 °C ~60 Within the temperature range of ℃, the density of the liquid crystal material of the present invention varies with temperature and the curvature range is -0.08%~0 , According to the picture 2 It can be seen that, compared with the prior art, the density of the liquid crystal material of the present invention changes with temperature at a slower speed than the prior art, so the liquid crystal material of the present invention has a smaller volume change due to temperature changes than the prior art. It should be noted that the calculation formula for the curvature of the density of the liquid crystal material as a function of temperature is: R=(A-B)/(60-(-20))= (A-B)/80 , R Is the curvature of the density of the liquid crystal material with temperature, A For liquid crystal materials in 60 Density at ℃, B For liquid crystal materials in -20 Density at ℃, A Less than B .

Further, in some embodiments of the present invention, the liquid crystal material is a photoreactive liquid crystal material, which further includes at least one reactive monomer.

Specifically, the structure of the reactive monomer is a first group with at least one acrylate group attached, and the first group is 2~4 A group formed by directly or indirectly connecting a benzene ring or a naphthalene ring; wherein, the 2~4 The indirect connection of a benzene ring specifically refers to 2~4 Each benzene ring is connected indirectly through a group.

Further, the at least one acrylate is directly connected to the first group, and the first group may be further connected to other polymerizable groups besides the acrylate, that is, the reaction The structure of the sexual monomer is formed by directly connecting at least one polymerizable group to the first group, and at least one of the at least one polymerizable group is an acrylate group.

Specifically, in some embodiments of the present invention, the upper substrate is a color filter substrate, on which a color filter layer, a black matrix separating the color filter layers and a black matrix are provided on the color filter layer and The common electrode on the black matrix, the lower substrate is an array substrate, and the TFT Array and the TFT Pixel electrodes electrically connected to the array.

In summary, the present invention provides a liquid crystal material comprising a mixed liquid crystal matrix and a thermal stabilizer, the concentration of the thermal stabilizer is greater than 50PPM And less than 3000PPM , By adding a concentration greater than 50PPM And less than 3000PPM The thermal stabilizer can make the density of the liquid crystal material change with temperature more slowly than that of the existing liquid crystal material. The application of this liquid crystal material to the liquid crystal display panel can reduce the temperature change. The resulting change in the volume of the liquid crystal material in the liquid crystal cell increases the control range of the liquid crystal volume, reduces product defects, and improves product quality. The invention provides a liquid crystal display panel, which can increase the control range of liquid crystal quantity, reduce product defects and improve product quality.

As mentioned above, for those of ordinary skill in the art, various other corresponding changes and modifications can be made according to the technical solutions and technical ideas of the present invention, and all these changes and modifications shall fall within the protection scope of the claims of the present invention. .

Claims (10)

1. A liquid crystal material includes a mixed liquid crystal matrix and a thermal stabilizer, the concentration of the thermal stabilizer is greater than 50 PPM and less than 3000 PPM.
2. 8. The liquid crystal material of claim 1, wherein the thermal stabilizer is a hindered phenolic material.
3. The liquid crystal material according to claim 1, in the temperature range of -20°C to 60°C, the curvature range of density changing with temperature is -0.08% to 0;

   Wherein, the formula for calculating the curvature of the density of the liquid crystal material with temperature is: R=(AB)/80, R is the curvature of the density of the liquid crystal material with temperature, A is the density of the liquid crystal material at 60°C, B Is the density of the liquid crystal material at -20°C, A is less than B.
4. The liquid crystal material of claim 1, further comprising at least one reactive monomer.
5. The liquid crystal material of claim 4, wherein the structure of the reactive monomer is a first group connected with at least one acrylate group, and the first group is a direct or indirect connection of 2 to 4 benzene rings. The formed group may be a naphthalene ring.
6. A liquid crystal display panel, comprising an upper substrate and a lower substrate arranged oppositely, and a liquid crystal layer arranged between the upper substrate and the lower substrate;

   The liquid crystal material used in the liquid crystal layer includes a mixed liquid crystal matrix and a thermal stabilizer, and the concentration of the thermal stabilizer is greater than 50 PPM and less than 3000 PPM.
7. 8. The liquid crystal display panel of claim 1, wherein the thermal stabilizer is a hindered phenolic material.
8. 3. The liquid crystal display panel of claim 1, wherein, within a temperature range of -20°C to 60°C, the density of the liquid crystal material varies with temperature in a range of -0.08% to 0;

   Wherein, the formula for calculating the curvature of the density of the liquid crystal material with temperature is: R=(AB)/80, R is the curvature of the density of the liquid crystal material with temperature, A is the density of the liquid crystal material at 60°C, B Is the density of the liquid crystal material at -20°C, A is less than B.
9. 5. The liquid crystal display panel of claim 1, further comprising at least one reactive monomer.
10. The liquid crystal display panel of claim 9, wherein the structure of the reactive monomer is a first group connected with at least one acrylate group, and the first group is directly or indirectly connected to 2~4 benzene rings. The formed group may be a naphthalene ring.