JP2009084566A - Liquid crystal, liquid crystal material mixture including the same and liquid crystal display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal and a liquid crystal material mixture which can be used for a liquid crystal display panel (LCD) and can present a satisfactory transmittance. <P>SOLUTION: The liquid crystal has the following characteristics. (I) Dielectric anisotropy (Δε) is in the range of about -2.5 to about -5. (II) Splay elastic constant (K<SB>11</SB>) is in the range of about 1.1×10<SP>-11</SP>N to about 1.6×10<SP>-11</SP>N. (III) Bend elastic constant (K<SB>33</SB>) is in the range of about 1.1×10<SP>-11</SP>N to about 1.6×10<SP>-11</SP>N. (IV) Δε, K<SB>11</SB>(N) and K<SB>33</SB>(N) satisfy the relation (1). The liquid crystal material mixture comprises the liquid crystal and a polymerizable monomer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal material mixture used in a liquid crystal used in a liquid crystal display panel (LCD), in particular, a PSA (Polymer Sustained Alignment) LCD.

  In the display device market, the LCD is the most established and popular display. LCDs have many advantages over conventional cathode ray tube (CRT) displays such as light weight, low power consumption, good portability, and no radiation. Therefore, it has been widely used in 3C products such as mobile phones, digital cameras, notebook computers, desktop display devices and the like.

  The characteristics of the liquid crystal material greatly affect the performance of the LCD. In general, liquid crystal materials are classified into positive liquid crystal materials (ie, Δε> 0) and negative liquid crystal materials (Δε <0) with respect to dielectric anisotropy (Δε). Positive liquid crystal materials are typically used for parallel alignment (PA) LCDs, and negative liquid crystal materials are typically used for vertical alignment (VA) LCDs.

  In order to improve the performance of LCDs, several assist liquid crystal alignment techniques have been proposed that give pretilt angles to the liquid crystal molecules in order to obtain LCDs characterized by fast response and high contrast ratio. One assist liquid crystal alignment technique is to add a polymerizable monomer to the liquid crystal material. When polymerized, the polymer imparts a pretilt angle to the liquid crystal molecules to achieve an assist alignment effect and improved optical properties. An LCD using such a liquid crystal material to which a polymerizable monomer is added is usually known as a PSA-LCD.

  However, the pixel structure of LCDs has become increasingly complex, especially with the development of multi-domain pixel structures, and the LCD industry is faced with the challenge of dealing with decreasing liquid crystal transmission. Simply put, the effective electric field is decreasing with the same driving voltage, and as a result, the transmittance of the liquid crystal material tends to decrease under the same conditions, which adversely affects the optical properties of the LCD Is exerting.

  In view of the above problems, the inventors of the present application have found through research that the optical performance, for example, transmittance of the LCD can be improved by selecting a liquid crystal material having specific characteristics.

One object of the present invention is to provide a liquid crystal display panel. The liquid crystal display panel includes a first substrate, a second substrate, and a plurality of liquid crystal molecules sealed between the first substrate and the second substrate, the plurality of liquid crystal molecules having the following characteristics:
(I) the dielectric anisotropy (Δε) ranges from about −2.5 to about −5;
(Ii) the spreading elastic constant (K ₁₁ ) ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iii) the flexural modulus (K ₃₃ ) ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iv) The relationship between Δε, K ₁₁ (N), and K ₃₃ (N) is represented by the following equation:
Have

Another object of the present invention is to provide a liquid crystal. This liquid crystal has the following characteristics:
(I) the dielectric anisotropy (Δε) ranges from about −2.5 to about −5;
(Ii) the spreading elastic constant (K ₁₁ ) ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iii) the flexural modulus (K ₃₃ ) ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iv) The relationship between Δε, K ₁₁ (N), and K ₃₃ (N) is represented by the following equation:
Have

Still another object of the present invention is to provide a liquid crystal material mixture containing the plurality of liquid crystal molecules and a polymerizable monomer.
With reference to the figures and methods described below, those skilled in the art will readily understand the spirit, other objects, technical means, and preferred embodiments of the present invention.

Studies have shown that when the drive voltage is increased to a certain level (about 10V), the transmittance of the liquid crystal material saturates regardless of its parameters. However, due to practical limitations of current display panels, the drive voltage employed is usually not suitable for saturating the transmittance. The above phenomenon can be explained by the graph of transmittance versus drive voltage in FIG. Two kinds of liquid crystal materials having different K ₁₁ , K ₃₃ and Δε, ie, a liquid crystal material LC1 (K ₁₁ = K ₃₃ = 1.33 × 10 ⁻¹¹ N, Δε = −3.5) and a liquid crystal material LC2 (K ₁₁ = K ₃₃ = 1.33 × 10 ⁻¹¹ N, Δε = −3.1) using the same pixel structure and the same measurement method. It has been found that the increase in transmittance as a function of voltage is quite different for the two liquid crystal materials. For example, at a normal driving voltage of 7.5 V, LC2 showed higher transmittance than LC1. Further studies have shown that K ₁₁ , K ₃₃ and Δε of the liquid crystal material are important factors affecting the transmittance when the driving voltage is the same.

Accordingly, the present invention provides a liquid crystal having specific characteristics. In particular, the parameters K ₁₁ , K ₃₃ and Δε of the present liquid crystal satisfy the following conditions.
(I) Δε ranges from about −2.5 to about −5;
(Ii) K ₁₁ ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iii) K ₃₃ ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iv) The relationship between Δε, K ₁₁ (N), and K ₃₃ (N) is expressed by the following equation.

  In accordance with the present invention, any liquid crystal having the above characteristics can be used in an LCD to provide adequate transmission and is not subject to any particular restrictions. The liquid crystal of the present invention is, for example (but not limited to), selected from the group consisting of compounds of the following general formulas (III), (IV), (V), and (VI).

ここで、R¹、R²、R³、R⁴、及びR⁶はそれぞれ他から独立に、１〜１２個の炭素原子を含むアルキル基であり、１つのCH₂基、又は互いに隣接していない２つのCH₂基は、-O-、-CH=CH-、-CO-、-OCO-、又は-COO-によって置換されてもよく、R⁵は２〜８個の炭素原子を含むアルケニル基であり、ｄは０または１であり、

Here, R ¹ , R ² , R ³ , R ⁴ and R ⁶ are each independently an alkyl group containing 1 to 12 carbon atoms and are adjacent to one CH ₂ group or to each other. Two CH ₂ groups not present may be substituted by —O—, —CH═CH—, —CO—, —OCO—, or —COO—, where R ⁵ is an alkenyl containing 2 to 8 carbon atoms. A group, d is 0 or 1,

は

Is

又は

Or

であり、

And

と

When

はそれぞれ他から独立に

Are independent of each other

又は

Or

であり、

And

は

Is

又は

Or

である。

It is.

In the preferred embodiment of the liquid crystal of the present invention, the adopted parameters K ₁₁ , K ₃₃ and Δε are as follows:
(I) Δε ranges from about −3 to about −5;
(Ii) K ₁₁ ranges from about 1.1 × 10 ⁻¹¹ N to about 1.55 × 10 ⁻¹¹ N;
(Iii) K ₃₃ ranges from about 1.1 × 10 ⁻¹¹ N to about 1.55 × 10 ⁻¹¹ N;
(Iv) The relationship between Δε, K ₁₁ (N), and K ₃₃ (N) is expressed by the following equation.

In another preferred embodiment of the liquid crystal of the present invention, the adopted parameters K ₁₁ , K ₃₃ and Δε are as follows:
(I) Δε ranges from about −3 to about −5;
(Ii) K ₁₁ ranges from about 1.37 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iii) K ₃₃ ranges from about 1.37 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iv) The relationship between Δε, K ₁₁ (N), and K ₃₃ (N) is expressed by the following equation.

As described above, the present invention provides an appropriate liquid crystal by selecting a liquid crystal having a specific combination of parameters (Δε, K ₁₁ , and K ₃₃ ). When this liquid crystal is used in an LCD, the optical performance of the LCD is improved.

  Accordingly, the present invention also provides LCDs, particularly PSA-LCDs. The LCD of the present invention includes a first substrate, a second substrate, and the liquid crystal of the present invention sealed between these substrates. The first electrode and the second electrode are disposed on the surface of the first substrate and the surface of the second substrate, respectively. If necessary, an alignment film (eg, polyimide) may be disposed on the first electrode and / or the second electrode.

  In the case of PSA-LCD, it further includes a polymer film disposed on the alignment film. This polymer film is polymerized from a polymerizable monomer. The polymerizable monomer used in the present invention is a photopolymerizable monomer, a thermopolymerizable monomer, or a combination thereof. This polymerizable monomer is, for example (but not limited to) selected from the group consisting of compounds of the following general formulas (I) and (II).

ここで、
P₁ は他から独立に、重合性基、例えば、アクリル酸塩またはメタクリル酸塩であり、
Sp₁ は他から独立に、スペーサ基、例えば、１つ以上の炭素原子を含む直線炭素鎖であり、
X₁ は他から独立に、-O-, -S-, -OCH₂-, -CO-, -COO-, -OCO-, -CO-NR-, -NR-CO-, -OCH₂-, -SCH₂-, -CH₂S-, -CH=CH-COO-, -OCC-CH=CH-または単一結合であり、ここでRはアルキル基であり、
L は他から独立に、-F, -Cl, -CNまたは１〜７個の炭素原子を含むアルキル基、アルキルカルボニル基、アルコキシカルボニル基またはアルキルカルボニルオキシ基であり、ｍは１以上であり、ここで、Lが１〜７個の炭素原子を含むアルキル基、アルキルカルボニル基、アルコキシカルボニル基またはアルキルカルボニルオキシ基である場合は、１つ以上のH原子はFまたはCl原子によって置換されてもよく、
Y は他から独立に、-H, -F, -Cl, -CN, -SCN, -SF₅H, -NO₂、１〜１２個の炭素原子を含む単一結合または分岐型アルキル基、又は-X₂-Sp₂-P₂であり、ここで、
P₂ は他から独立に、重合性基、例えば、アクリル酸塩またはメタクリル酸塩であり、
Sp₂ は他から独立に、スペーサ基、例えば、１つ以上の炭素原子を含む直線炭素鎖であり、
X₂ は他から独立に、-O-, -S-, -OCH₂-, -CO-, -COO-, -OCO-, -CO-NR-, -NR-CO-, -OCH₂-, -SCH₂-, -CH₂S-, -CH=CH-COO-, -OCC-CH=CH-または単一結合であり、ここでRはアルキル基である。

here,
P ₁ is independently of the other polymerizable group, such as an acrylate or methacrylate,
Sp ₁ is independently of the others a spacer group, for example a straight carbon chain containing one or more carbon atoms,
X ₁ is independently of the other, -O-, -S-, -OCH _2- , -CO-, -COO-, -OCO-, -CO-NR-, -NR-CO-, -OCH _2- , -SCH _2- , -CH ₂ S-, -CH = CH-COO-, -OCC-CH = CH- or a single bond, wherein R is an alkyl group,
L is independently from the other -F, -Cl, -CN or an alkyl group containing 1 to 7 carbon atoms, an alkylcarbonyl group, an alkoxycarbonyl group or an alkylcarbonyloxy group, m is 1 or more, Here, when L is an alkyl group containing 1 to 7 carbon atoms, an alkylcarbonyl group, an alkoxycarbonyl group or an alkylcarbonyloxy group, one or more H atoms may be substituted by F or Cl atoms. Often,
Y is independently from the other -H, -F, -Cl, -CN, -SCN, -SF ₅ H, -NO ₂ , a single bond or branched alkyl group containing 1 to 12 carbon atoms, or -X ₂ -Sp ₂ -P ₂ where
P ₂ is independently of the other polymerizable group, for example, acrylate or methacrylate,
Sp ₂ is independently of the others a spacer group, for example a linear carbon chain containing one or more carbon atoms,
X ₂ is independently of the other, -O-, -S-, -OCH _2- , -CO-, -COO-, -OCO-, -CO-NR-, -NR-CO-, -OCH _2- , -SCH _2- , -CH ₂ S-, -CH = CH-COO-, -OCC-CH = CH- or a single bond, wherein R is an alkyl group.

  In order that those skilled in the art can easily understand an LCD according to an embodiment of the present invention, a PSA-LCD as one embodiment will be described below with reference to the accompanying drawings. In the drawings, similar elements are denoted by the same reference numerals.

  FIG. 2 illustrates a PSA-LCD 20 according to this embodiment of the invention. The LCD 20 includes a first substrate 211, a second substrate 213, and the liquid crystal 11 of the present invention sealed between these substrates. The first electrode 251 and the second electrode 253 are provided on the surface of the first substrate 211 and the surface of the second substrate 213, respectively, and provide an electric field for twisting the liquid crystal 11. Further, as shown in FIG. 2, an alignment film 27 is provided on the surface of the first electrode 251 and the surface of the second electrode 253 so as to align the liquid crystal 11. A polymer film 29 is provided on the surface of the alignment film 27 to assist the alignment of the liquid crystal 11. In addition, as shown in FIG. 2, the two substrates are usually separated by a predetermined distance in the range of about 2.5 μm to about 10 μm, that is, a cell gap 23.

  In manufacturing the LCD of the present invention, any appropriate process such as a color filter manufacturing process, a thin film transistor array process, a liquid crystal cell process, and a module assembly process can be used. These steps are well known in the art, and details thereof are omitted. In the case of PSA-LCD, the polymer film disposed on the alignment film is prepared by injecting or dropping a liquid crystal material mixture containing a polymerizable monomer in addition to the liquid crystal of the present invention into an LCD cell. Can be provided by polymerizing and forming a polymer film on the alignment film.

  Therefore, as described above, the present invention also relates to a liquid crystal material mixture containing the liquid crystal of the present invention and a polymerizable monomer. According to the present invention, the concentration of polymerizable monomer may be determined by one skilled in the art according to actual requirements. In general, the concentration of the polymerizable monomer ranges from about 0.01% to about 5% by weight of the liquid crystal.

  The following examples are provided to further illustrate the invention so that those skilled in the art may better understand the advantages and technical features of the invention.

Example 1
A transmittance simulation is performed using liquid crystal materials 1 to 5 on a vertical alignment LCD, and a spreading elastic constant (K ₁₁ ), a torsional elastic constant (K ₂₂ ), a bending elastic constant (K ₃₃ ), and a dielectric anisotropy The effects of (Δε) and viscosity coefficient (γ) on the transmittance were observed. The results are shown in Table 1.

Table 1 shows that K ₁₁ , K ₃₃ , and Δε more reflect the transmittance of the liquid crystal material compared to K ₂₂ and γ. More specifically, from the results of the liquid crystal materials 1 and 5, when K ₁₁ , K ₃₃ , γ, and Δε are fixed, the liquid crystal materials 1 and 5 having different K ₂₂ values (0.8 and 0.5, respectively) It can be seen that there is no significant difference in transmittance (24.1% and 24.0% at 7V voltage, and 18.1% at 4.2V voltage, respectively). Similarly, from the results of the liquid crystal materials 3 and 4, when K ₁₁ , K ₂₂ , K ₃₃ , and Δε are fixed, the liquid crystal materials 3 and 4 (0.11 and 0.14, respectively) having different γ values are transmitted. It can be seen that there is no significant difference in the rate (24.1% and 24.0% at 7V voltage, and 21.6% at 4.2V voltage, respectively). On the other hand, from comparison between the liquid crystal materials 1 and 2, when K ₂₂ , γ, and Δε are fixed, the transmission of the liquid crystal materials 1 and 2 having different K ₁₁ and K ₃₃ values at a low driving voltage (for example, 4.2 V). The ratios are greatly different at 18.1% and 24.6%, respectively, indicating that the liquid crystal material 2 has good performance in terms of transmittance. Further, from the comparison between the liquid crystal materials 1 and 3, when K ₁₁ , K ₃₃ , K ₂₂ , and γ are fixed, the liquid crystal materials 1 and 3 having different Δε values at low driving voltage (for example, 4.2 V) (respectively, −3 and −3.5) have a large difference between 18.1% and 21.6%, respectively, which indicates that the liquid crystal material 3 has good performance in terms of transmittance.

From Example 1, it is understood that when the liquid crystal parameters K ₂₂ , γ, and Δε are fixed, the parameters K ₁₁ and K ₃₃ affect the transmittance of the liquid crystal material. On the other hand, when K ₁₁ , K ₃₃ , K ₂₂ , and γ are fixed, the parameter Δε affects the transmittance of the liquid crystal material.

Example 2
The LCD having the structure shown in FIG. 2 was tested by changing only the liquid crystal 11 without changing other elements.

First, the liquid crystal material 1 having the parameters Δε = −3, K ₁₁ = 1.52 × 10 ⁻¹¹ N, K ₃₃ = 1.55 × 10 ⁻¹¹ N was used as the liquid crystal 11. Next, optical measurement was performed on the assembled LCD using a transmittance meter. The measurement results are shown in Table 2 (LC1).

Next, a liquid crystal material 2 having parameters Δε = −3, K ₁₁ = 1.37 × 10 ⁻¹¹ N, K ₃₃ = 1.41 × 10 ⁻¹¹ N was used as the liquid crystal 11. Next, optical measurement was performed on the assembled LCD using a transmittance meter. The measurement results are shown in Table 2 (LC2).

Next, a liquid crystal material 3 having parameters of Δε = −3.5, K ₁₁ = 1.52 × 10 ⁻¹¹ N, K ₃₃ = 1.5 × 10 ⁻¹¹ N was used as the liquid crystal 11. Next, optical measurement was performed on the assembled LCD using a transmittance meter. The measurement results are shown in Table 2 (LC3).

As shown in Table 2, when Δε is fixed, the transmittance (%) of the liquid crystal material 2 having a K ₁₁ value of 13.7 and a K ₃₃ value of 14.1 is K ₁₁ value. It can be seen that it is better than the liquid crystal material 1 with 15.2 and K ₃₃ value of 15.5. That is, the liquid crystal material 2 has a transmittance (%) of 3.9, and the liquid crystal material 1 has a transmittance (%) of 3.7. Similarly, from a comparison of the liquid crystal material 1 and 3, the case of fixing the K _11, the transmittance of the [Delta] [epsilon] values -3.5, the liquid crystal material 3 K ₃₃ value of 15 (%) is, [Delta] [epsilon] values -3, K ₃₃ value It can be seen that it is better than the liquid crystal material 1 of 15.5. That is, the liquid crystal material 3 has a transmittance (%) of 4.4, and the liquid crystal material 1 has a transmittance (%) of 3.7.

As can be seen from the second embodiment, the transmittance of the LCD can be effectively improved by selecting an appropriate liquid crystal material having Δε, K ₁₁ , and K ₃₃ values.

  The above disclosure relates to the detailed technical contents and inventive features of the present invention. Those skilled in the art may envision various modifications and substitutions based on the above disclosure and presentation of the present invention without departing from the scope of the present invention. Such modifications and substitutions are not fully disclosed herein but are substantially included in the appended claims.

It is a graph which compares the transmittance | permeability versus drive voltage characteristic when a liquid crystal parameter is changed in the same LCD structure. It is the schematic of LCD of one Embodiment of this invention.

Explanation of symbols

11 Liquid crystal molecules 20 PSA-LCD
23 cell gap 27 alignment film 29 polymer film 211 first substrate 213 second substrate 251 first electrode 253 second electrode

Claims (23)

A first substrate (211);
A second substrate (213);
A plurality of liquid crystal molecules (11) sealed between the first substrate (211) and the second substrate (213), the plurality of liquid crystal molecules having the following characteristics:
(I) the dielectric anisotropy (Δε) ranges from about −2.5 to about −5;
(Ii) the spreading elastic constant (K ₁₁ ) ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iii) the flexural modulus (K ₃₃ ) ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iv) The relationship between Δε, K ₁₁ (N), and K ₃₃ (N) is represented by the following equation:
A liquid crystal display panel.

The Δε is in the range of about −3 to about −3.5, and the K ₁₁ and K ₃₃ are each independently in the range of about 1.1 × 10 ⁻¹¹ N to about 1.55 × 10 ⁻¹¹ N. 2. A liquid crystal display panel according to 1.   2. The liquid crystal display panel according to claim 1, wherein the [Delta] [epsilon] ranges from about -3.0 to about -5. The liquid crystal display panel according to claim 1, wherein the K ₁₁ ranges from about 1.37 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N. The liquid crystal display panel according to claim 1, wherein the K ₃₃ ranges from about 1.37 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N. A first electrode (251) and a second electrode (253) provided opposite to each other on the surface of the first substrate (211) and the surface of the second substrate (213);
The liquid crystal display panel according to claim 1, further comprising one or more alignment films (27) provided on the first electrode (251) and / or the second electrode (253).   The liquid crystal display panel according to claim 6, further comprising a polymer film (29) provided on the alignment film (27).   The liquid crystal display panel according to claim 1, wherein a predetermined cell gap (23) ranging from about 2.5 µm to about 10 µm exists between the first substrate (211) and the second substrate (213). The following characteristics,
(I) the dielectric anisotropy (Δε) ranges from about −2.5 to about −5;
(Ii) the spreading elastic constant (K ₁₁ ) ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iii) the flexural modulus (K ₃₃ ) ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iv) The relationship between Δε, K ₁₁ (N), and K ₃₃ (N) is represented by the following equation:
Liquid crystal having.

Negative type liquid crystal, the following general formula (III), (IV), (V) or (VI),

Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁶ are each independently an alkyl group containing 1 to 12 carbon atoms, one CH ₂ group, Or two CH ₂ groups that are not adjacent to each other may be substituted by —O—, —CH═CH—, —CO—, —OCO—, or —COO—, and R ⁵ is 2-8 An alkenyl group containing carbon atoms, d is 0 or 1,

Is

Or

And

When

Are independent of each other

Or

And

Is

Or

The liquid crystal according to claim 9, comprising the compound The Δε is in the range of about −3 to about −3.5, and the K ₁₁ and K ₃₃ are each independently in the range of about 1.1 × 10 ⁻¹¹ N to about 1.55 × 10 ⁻¹¹ N. 9. The liquid crystal according to 9.   The liquid crystal of claim 9, wherein Δε is in the range of about −3.0 to about −5. The liquid crystal according to claim 9, wherein the K ₁₁ ranges from about 1.37 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N. The liquid crystal according to claim 9, wherein the K ₃₃ ranges from about 1.37 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N. Including liquid crystal and a polymerizable monomer,
The liquid crystal has the following characteristics:
(I) the dielectric anisotropy (Δε) ranges from about −2.5 to about −5;
(Ii) the spreading elastic constant (K ₁₁ ) ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iii) the flexural modulus (K ₃₃ ) ranges from about 1.1 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N;
(Iv) The relationship between Δε, K ₁₁ (N), and K ₃₃ (N) is represented by the following equation:
A liquid crystal material mixture having:

  The liquid crystal material mixture according to claim 15, wherein the polymerizable monomer is a photopolymerizable monomer, a thermally polymerizable monomer, or a combination thereof. The polymerizable monomer is represented by the following general formula (I) or (II),

A compound represented by:
P ₁ is, independently of the others, acrylate or methacrylate,
Sp ₁ is a linear carbon chain containing one or more carbon atoms, independent of the others,
X ₁ is independently of the other, -O-, -S-, -OCH _2- , -CO-, -COO-, -OCO-, -CO-NR-, -NR-CO-, -OCH _2- , -SCH _2- , -CH ₂ S-, -CH = CH-COO-, -OCC-CH = CH- or a single bond, wherein R is an alkyl group,
L is independently from the other -F, -Cl, -CN or an alkyl group containing 1 to 7 carbon atoms, an alkylcarbonyl group, an alkoxycarbonyl group or an alkylcarbonyloxy group, m is 1 or more, Here, when L is an alkyl group containing 1 to 7 carbon atoms, an alkylcarbonyl group, an alkoxycarbonyl group or an alkylcarbonyloxy group, one or more H atoms may be substituted by F or Cl atoms. Often,
Y is independently of the others -H, -F, -Cl, -CN, -SCN, -SF ₅ H, -NO ₂ , an alkyl group containing 1 to 12 carbon atoms, or -X ₂ -Sp ₂ -P ₂ where
P ₂ is, independently of the others, acrylate or methacrylate,
Sp ₂ is a linear carbon chain containing one or more carbon atoms, independent of the others,
X ₂ is independently of the other, -O-, -S-, -OCH _2- , -CO-, -COO-, -OCO-, -CO-NR-, -NR-CO-, -OCH _2- , The compound according to claim 16, comprising —SCH ₂ —, —CH ₂ S—, —CH═CH—COO—, —OCC—CH═CH—, or a single bond, wherein R is an alkyl group. Liquid crystal material mixture. The liquid crystal is a negative type liquid crystal, and the following general formula (III), (IV), (V) or (VI),

Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁶ are each independently an alkyl group containing 1 to 12 carbon atoms, one CH ₂ group, Or two CH ₂ groups that are not adjacent to each other may be substituted by —O—, —CH═CH—, —CO—, —OCO—, or —COO—, and R ⁵ is 2-8 An alkenyl group containing carbon atoms, d is 0 or 1,

Is

Or

And

When

Are independent of each other

Or

And

Is

Or

The liquid crystal material mixture according to claim 15, comprising a compound that is:   The liquid crystal material mixture according to claim 15, wherein the concentration of the polymerizable monomer is in the range of about 0.01 wt% to about 5 wt% of the weight of the liquid crystal. The Δε is in the range of about −3 to about −3.5, and the K ₁₁ and K ₃₃ are each independently in the range of about 1.1 × 10 ⁻¹¹ N to about 1.55 × 10 ⁻¹¹ N. 15. A liquid crystal material mixture as described in 15.   The liquid crystal material mixture of claim 15, wherein the Δε is in the range of about −3.0 to about −5. The liquid crystal material mixture of claim 15, wherein the K ₁₁ ranges from about 1.37 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N. The liquid crystal material mixture of claim 15, wherein the K ₃₃ ranges from about 1.37 × 10 ⁻¹¹ N to about 1.6 × 10 ⁻¹¹ N.

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