JPS58129058A - Disazo type multicolored dyestuff and liquid crystal composition and display body containing said dyestuff - Google Patents

Abstract

NEW MATERIAL:A compound of formulaI[R is 3-18C alkyl; X is H, (cyclo) alkyl, nitro, cyano, aryl, halogen, etc.; Z<1>-Z<9> are H, halogen, methyl, OH or methoxyl; Z<1> and Z<2>, Z<4> and Z<5>, or Z<7> and Z<8> together may like to form an aromatic ring]. EXAMPLE:A compound of formula II. USE:A liquid crystal composition or display body capable of giving clear displays having high contrast of parallel dichromatic multicolored dyestuff. PROCESS:A compound of formula III is reacted with a compound of formula IV (Y is halogen).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disazo pleochroic dye, a liquid crystal composition containing the dye, and a display.

Pleochroic dyes absorb light in the direction of the dye molecules.This dye has the highest absorption intensity when the direction of the absorption transition moment is parallel to the electric vector of the light, and when the direction of the absorption transition moment is parallel to the electric vector of the light. The absorption intensity is the smallest when

In the liquid crystal display element described above, the orientation of the dye molecules can be changed by utilizing the fact that the alignment direction of liquid crystal molecules changes when an electric field is applied. The color of the liquid crystal display element can be changed by applying voltage. *This color change is called the guest-host effect, considering the crystalline compound as the host and the dye as the guest. Among pleochroic dyes, especially those with parallel dichroism, the absorption transition moment of visible light is The direction is almost parallel to the long axis direction of the molecules, and when dissolved as a guest molecule in the host liquid crystal, when =fC, the dye molecule long axes have the property of being aligned in the same direction as the alignment direction of the liquid crystal molecular axes.

For example, in a liquid crystal display element in which the liquid crystal composition consists of a pleochroic dye with parallel dichroism and a nematic liquid crystal compound with positive dielectric anisotropy, and is subjected to homogeneous alignment treatment, the long axis of one dye molecule is Like the molecules, they form a homogeneous alignment that is parallel to the electron plane and aligned in a fixed direction.In the liquid crystal layer in such an aligned state, the molecules travel in a direction perpendicular to the electron plane, and in the same direction as the alignment direction of the liquid crystal molecules. When polarized nine-white light propagates, its electric vector becomes parallel to the dye molecules, and a specific wavelength region is particularly strongly absorbed.As a result, the liquid crystal layer takes on a strongly colored state. When , the long axes of the dye molecules form a homeotropic alignment since the dielectric anisotropy of the host liquid crystal is positive.

The long axis of the dye molecule is perpendicular to the electric vector of the incident white light, so that the incident light is hardly absorbed by the dye molecule, resulting in an oddly colored state of the liquid crystal layer Fi.

The guest-host effect can be obtained not only by using a nematic liquid crystal compound as described above, but also by using a smectic liquid crystal compound or by using a cholesteric-nematic phase transition. In the bonding using phase transition, each cholesteric liquid crystal molecule is arranged in a spiral shape in an element subjected to homogeneous alignment treatment. #When IIK white light propagates perpendicularly to the electrode surface in the liquid crystal layer, the dye molecules are oriented in various directions, so a specific wavelength range of all polarized light components is particularly strongly absorbed by the dye molecules. As a result, the liquid crystal layer is in a strongly colored state due to the zero-order K
When a voltage is applied to the M liquid crystal island, if the dielectric anisotropy of the cholesteric liquid crystal is positive, the spiral molecular arrangement is dissolved and the long axes of the dye molecules form a homeotropic alignment like the liquid crystal molecules. As a result, the liquid crystal layer becomes weakly colored.

The above pleochroic dyes include (1) high order parameters in the host liquid crystal (represented by the symbol S); (2) sufficient 111#f for the host liquid crystal, i3+ high stability against light, heat, and electricity; Parallel K 141 An arbitrary hue is required depending on the purpose.Kd At least (1) and (2) above are required in order to enhance the contrast of the special label.

The order parameter date is defined by Equation (1), and is experimentally determined by Equation (1). In the formula, the term cos'# is time-averaged, θ is the angle between the absorption axis of the dye molecule and the alignment direction of the liquid crystal molecules, and A/mu is the angle between the absorption axis of the dye molecule and the alignment direction of the liquid crystal molecules, respectively. and the absorbance of the dye molecule for vertically polarized light.

S w-(j cos"θ-7)/λ...
... (1) S-(A/-A soil)/(λ artificial + A/)...
...(II) In parallel dichroic pleochroic dyes, the closer the S value is to the theoretical maximum value, the weaker the colored state111
The degree of residual color in the display is reduced, making it possible to display bright and clear images with high contrast.

An object of the present invention is to provide a liquid crystal composition and a display body capable of performing clear display with a novel parallel dichroic pleochroic dye contrast that satisfies the requirements of (1), (27, and (31) above. It is in.

The relationship between the molecular bridge structure of pleochroic dyes and their properties has not yet been fully clarified, and it is a difficult task to select a pleochroic dye that satisfies all of the above-mentioned performance requirements in a desired hue. , it is not easy to make an analogy and select from known materials.

As a result of extensive research, the inventor of the present invention has completed the present invention by discovering that the Mader parameter and solubility can be improved by introducing a benzene ring into a disazo dye matrix through an ester bond.

That is, the gist of the present invention is the general formula [I] ...................................... [■] (wherein, R is an alkyl group having 3 to // carbon atoms, Indicates atoms, alkyl groups, cycloalkyl groups, alkoxy groups, nitro groups, cyano groups, carboxylic acid ester groups, aryl groups, alkylsulfonyl groups, and halogen atoms.
Zl~2" Water X atom, halogen atom, methyl group, fluoroxy group, methoxy group, or zt, Z! or Z"
+ 2”'*Takezt.

z6 may be linked to each other to form an aromatic ring.)
A disazo pleochroic dye represented by the following, a liquid crystal composition containing the dye, and a display body.

To explain the present invention in detail, the disazo pleochroic dye represented by the general formula [■] is a novel dye which has excellent order parameters and solubility inertia with respect to liquid crystal materials, and has good stability.

Specific examples of R in the general formula (INK) include alkyl groups such as a propyl group, a butyl group, a hexyl group, an octyl group, a dodecyl group, an octadecyl group, etc. Specific examples of %X Examples include hydrogen atom; alkyl groups such as methyl group, ethyl group, linear or branched propyl group, butyl group, heptyl group, octyl group, dodecyl group, and octadecyl group; cyclohexyl group, propylcyclohexyl group, butyl group. Cyclohexyl group, heptyl cyclohexyl group (1) Cy/roalkyl group; methoxy group, propoxy group, pentoxy group, octoxy group, octadecyloxy group, etc.; nitro group; cyano group; methoxycarbonyl group, butoxycarbonyl group, octadecyloxy group; Groups of carboxylic acid esters such as oxycarbonyl group, propylcyclohexyloxycarbonyl group, heptylcyclohexyloxycarbonyl group, polyphenoxycarbonyl group, butoxyphenoxycarbonyl group, pentylcyclohexyphenoxycarbonyl group; ethylsulfonyl group, butyl Alkylsulfonyl groups such as sulfonyl group and octylsulfonyl group; 7-aryl groups such as phenyl group, butylphenyl group, octylphenyl group, butoxyphenyl group ζ butyloxyphenyl group; Examples include rogen atoms.

Specific examples of zt and ze include a hydrogen atom, a halogen atom such as a fluorine atom, a chlorine atom, and a bromine atom, a methyl group, a hydroxy group, a methoxy group, a cyano group, or Z' e Z''
7, 4.7. N, zl, and za may be linked to each other to form a part of an aromatic ring.

The disazo pleochroic dye represented by the general formula (1) is
For example, a compound represented by the following formula [Seal] Z@ZQ (wherein, !, Zl, and Z" have the same meanings as in the general formula [1) above) and the following formula [1] ( In the formula, Y represents a halogen atom, and R represents the general formula CI
) has the same meaning as in K. ) The nematic liquid crystal used in the present invention, which is manufactured by reacting a compound represented by be able to.

Furthermore, by adding an optically active substance to such a nematic liquid crystal, it can be made to take a cholesteric state. Examples of nematic liquid crystals include the substances shown in Table 1.
The derivatives of Aruike and H et al.

Table 7 In the above table, R/key alkyl group or alkoxy group,
represents a nitro group, a cyano group, or a halogen atom. All of the liquid crystals in Table 1 have positive dielectric anisotropy, but the liquid crystals that have negative dielectric anisotropy are known ester-based, azoxy-based, azo-based,
Schiff-based, pyrimidine-based, diester-based, or biphenyl ester-based liquid crystals can also be mixed with liquid crystals having positive pm anisotropy (2) to form positive liquid crystals as a whole.

Furthermore, it goes without saying that even a liquid crystal having negative dielectric anisotropy can be used as is, provided that an appropriate element configuration and driving method are used.

The host liquid crystal substance used in the present invention may be any of the liquid crystal compounds shown in Table 1 or a mixture thereof, but the following four
ZL from Merck & Co. as a mixture of liquid crystal compounds of the type
%Br1tish Drug Haus as a mixture of the liquid crystal material sold under the trade name I-//J and the following types of liquid crystal compounds:
A liquid crystal material sold under the trade name E-7 by E Company has been found to be particularly useful in the present invention.As optically active substances to be added to the liquid crystal composition of the present invention, chiral nematic compounds, e.g. , -monomethylbutyl group,
There are compounds in which optically active groups such as 3-methylbutoxy group, J-methylpentyl group, 3-methylpentoxy group, goomethylhexyl group, goomethylhexyl group are introduced into nematic liquid crystal compounds. Also! P! j open @zi-f
Alcohol derivatives such as t-menthol and d-borneol shown in Publication No. 6, d-camphor, ketone derivatives of J-methylcyclohexane, d-citronellaic acid, carboxylic acid visiting conductors of l-camphor and m, d-citronellal Of course, optically active substances such as aldehyde derivatives such as d-linonene, alkene derivatives such as d-linonene, and other amine, amide, and nitrile derivatives can be used.

As the element used in the present invention, a known liquid crystal display element can be used. That is, in general, at least four transparent electrodes are provided in an arbitrary pattern on a single glass substrate, one of which is transparent, and a suitable spacer is placed so that the electrode surfaces face each other.
A device is used in which the device is constructed such that two glass substrates are parallel to each other. In this case, the gap between the elements is determined by the spacer. The element gap is J~110
0p, %! -! 0prn is preferred from a practical standpoint.

Examples of parallel dichroic pleochroic dyes used in the liquid crystal composition of the present invention and a parallax liquid crystal composition using these dyes will be specifically explained below using Examples.

Examples - Synthesis examples of pleochroic dyes of the present invention are shown, and Table 12 shows order parameters (8), EL and maximum absorption wavelength (
λmA! ) is shown.

Synthesis Example-1 p-n-hexyloxybenzoic II & 6 is dioxane! A known method is shown by the following structural formula. Is it possible to synthesize azo compounds?
, J f, dioxane 30d, triethylamine 10-
was added and reacted at /Q°C for 3 hours.

After cooling to mold temperature, water! The precipitate obtained by discharging into cOgd was purified by column chromatography,
This dye number 121-1 was obtained from the dyes shown in Table I6 below.
It showed a melting point of 241°C.

Synthesis Example - λ Synthesis Example - Use p-n-butoxybenzoic acid in place of p-n-hexyloxybenzoic acid, /f in place of p-n-hexyloxybenzoic acid, and use the following structure in place of the azo compound shown by the structural formula. Using an azo compound synthesized by a known method represented by the formula, the other procedures were the same as in Synthesis Example 7. Table 1 shows examples of azo pleochroic dyes of the present invention synthesized according to Synthesis Example 1 above.

The characteristics of each pigment listed in Table 1 are as follows: 1. I looked it up. That is, one of the dyes shown in Table 1 is added as a percent pleochroic dye to the above-mentioned phenylcyclohexane-based mixed liquid crystal ZL//J-, and heated to 20° C. or higher to turn the liquid crystal into an orthogonal liquid. After stirring well, the process of leaving to cool was repeated to dissolve the dye.

The above liquid crystal composition prepared as shown in Fig. 1 was prepared between two glass substrates, each having a transparent electrode and a polyamide thread resin coated on the surface in contact with the liquid crystal, cured, and then rubbed to give a homogeneous alignment treatment. It was sealed in a device with a gap of 1o-iooμm. When no voltage is applied in the element subjected to the above-mentioned alignment treatment, the above-mentioned liquid crystal composition assumes a homogeneous alignment state as shown in the first INK, and the dye molecules also assume a similar alignment according to the host liquid crystal.

The structure of the liquid crystal display element shown in FIG. 1 is a common one except that the liquid crystal composition of this example is sealed.

That is, the element has upper and lower transparent glass substrates.

The liquid crystal composition of this embodiment is comprised of transparent electrodes λ formed inside each substrate, and liquid crystal molecules J and pleochroic dye molecules D sandwiched between the substrates. The incident natural light I passes through the polarizing plate and is polarized in the incident light polarization direction 2, and reaches the element together with the incident white polarized light t. Sue and Ri are observers.

The measurement of the absorption spectrum of the liquid crystal composition of this example was carried out using light polarized parallel to the orientation direction of crystal molecules and light polarized perpendicularly to the dye corresponding to each polarized light. Absorption ij A / and absorption of the dye to find the maximum absorption wavelength yt, K to find the degree Ifi, absorption by the host liquid crystal and glass substrate, and reflection loss K of the element
Correction was made using pA. The S value was calculated from the above formula (1) using the luminosity values M1 and M1 of the dye for each polarized light obtained by K in this way.2Practical use of the dyes listed in Table 2. Accelerated deterioration tests were conducted to gain knowledge regarding the stability of the product. That is, the above-mentioned liquid crystal composition in which each of the dyes listed in Table 1 was dissolved was sealed in the above-mentioned element, and then the liquid crystal composition was left in a sunshine weather meter for about 100 hours, and the rate of decrease in absorbance and the rate of increase in current consumption were monitored. The light source of the sunshine weather meter used in this example was a carbon arc lamp, and the temperature inside the sample chamber was approximately 100%. No humidification or water sprinkling was performed at 0°C.

As a result, when the above test was conducted while protecting the above element with a UV cut filter, accelerated deterioration test 11A1
At 00 hours, the rate of decrease in absorbance for each dye in Table 1 was 70% or less, 3aHz,! The increase in the current consumption value when AC is applied in (2) was within 0%. Color fading is low with flat// pigments, and the element can be protected with a UV cut filter.
Even if you perform the above test without doing so.

Decrease rate of absorbance Fii after 100 hours of accelerated deterioration.

% or less. Such excellent light resistance.

The pleochroic dyes known so far for guest-host display are comparable to the types of antoquinone dyes with high photostability shown below.

? ! MaSho 58-129058 (8) Such high light fastness was not known in the conventional type of azo pleochroic dyes, and was achieved for the first time, at least in practical terms, by #JK. Even though an azo-based pleochroic dye with the same level of light resistance as anthraquinone-based pleochroic dye has been achieved, it is not 4m-high.

The dye according to the present invention has excellent thermal stability, and the decrease rate of the absorbance of the dye in the device after ioo hours at 0°C under 9°dark conditions (Fi10X or more)%3-81, the current consumption when jV AC is applied. The increase rate was less than Fi- times.

[Brief explanation of the drawing]

1 and 3 are schematic cross-sectional views of an example device of the present invention in a state where no voltage is applied; FIG. 1 is a spectral characteristic diagram of an example device of the present invention using the dye shown in Table AI; FIG. 1 is a schematic cross-sectional view of a device according to an embodiment of the present invention in a voltage applied state. ３・・・・・・・Liquid crystal molecules, ta・・・・・・・
Pleochroic purple molecule Applicant: Sanen Kagen Kogyo Co., Ltd. Hitachi Construction Co., Ltd. Attorney: Patent attorney - Others / Naguri 1 Figure 2 Figure difference 3 Figure 4 Continuation of figure 1 page 0 Inventor: Mikio Sato, 3-1-1, Saiwai-cho, Hitachi-shi, Japan Shares: % 0 Applicant: Hitachi, Ltd., 5-1, Marunouchi-chome, Chiyoda-ku, Tokyo

Claims (2)

[Claims] (1) General formula [! ] 7, a ZQ ZQ -・・・・・・・・・−(1) (In the formula, R is an alkyl M having 3 to 1 carbon atoms, and X is a hydrogen atom, an alkyl group, a Schifftetraalkyl group, an alkoxy group , Nido I group, cyano group, carboxylic acid ester group, aryl group, alkylsulfonyl group, halogen atom, %
21~ are hydrogen atoms, halogen atoms, and methyl groups. Human tetraxy group, methoxy group, or Z'*Z"t or z4
．． A disazo pleochroic dye represented by zJ, zt, and za may be linked to each other to form an aromatic ring. (2) General formula [I] Z" ZQ ZQ...
......-[I] (In the formula, R is an alkyl group having 3 to /r carbon atoms, and X is a hydrogen atom, an alkyl group, a cyclofurkyl group, an alkoxy group, a nitro group, or a cyano group. Indicates a carboxyl ester group, an aryl group, an alkylsulfonyl group, a halogen atom, g1-2 is a hydrogen atom,
Hashigen Houshi, methyl group. Hydroxy group, methoxy group, or Zl, Ft or z't
A liquid crystal composition containing a disazo pleochroic dye represented by z't, By, and zi may be interconnected to form an aromatic ring. <3) General formula (1) Z" Z@ Z...-
...-[1] (In the formula, R is an alkyl having 3 to // carbon atoms, a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a nitro group, a cyano group. A carboxylic acid ester group. , aryl group, alkylsulfonyl group, halogen II child t indicates, %Zl~z0 is a hydrogen atom, a halogen atom, a methyl group.
．． A display material using a liquid crystal composition containing a disazo pleochroic dye represented by zl, zt, and za may be linked to each other to form an aromatic ring.