JPS58142968A - Two-color dye for liquid crystal - Google Patents

Abstract

PURPOSE:Two-color dye for liquid crystal having a high two-color ratio, high coloring power, capable of providing sufficient display color with its small amount, having improved compatibility with a liquid crystal, not precipitating even at low temperature, comprising a trisazo-based compound shown by a specific formula. CONSTITUTION:The desired two-color dye comprising a trisazo-based compound shown by the formulaI{X is group shown by the formula II[R2 is H, CH3 or OCH3; p is 1-3], or formula III; Y is group shown by the formula IV[R3 is group shown by the formula V, formula VI, OR6, SR6, etc. (R4-R6 are H, group shown by the formula VII, etc.)], or formula VIII; R1 is H, halogen, CN, SCN, OH, SH, CnH2n+1, fluoroalkyl obtained by replacing H of CnH2n+1 with fluorine, SO2CnH2n+1, fluoroalkylsulfonyl obtained by replacing H of SO2CnH2n+1 with fluorine, OCnH2n+1, SCnH2n+1, O(CnH2n)-O-(CnH2m+1), OCOCnH2n+1 (n and m are 1-8), etc.}. EFFECT:Capable of providing an ideal liquid crystal display device of the guest host type having improved display contrast, response, and display color not fading for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION [zeta]O is used to prepare dust and liquid crystal dyes used in liquid crystal display devices.

General Kr strike/main strike MS crystal display device is contrast)
It is said that the display is continuous in that the 0 stormy display is reduced to row 1, the responsiveness to display driving is good, and the II'i display color does not bleed or fade around the long steel.

On the other hand, the display contrast of a dust/host lid liquid crystal display device is mainly influenced by the dichroic ratio of the dichroic dye mixed into the liquid crystal, but if the coloring ability of the dye is low, the displayed color will change. As the color becomes thinner, the dichroism ratio of the coloring material is high, making it impossible to obtain sufficient display contrast. If the coloring ability of the dye is low, it is necessary to increase the amount of dye O added to the liquid crystal to make the displayed color dull. In this case, the response to display driving becomes worse.

In addition, in dust/host lid liquid crystal display devices, if the compatibility of the dichroic dye with the liquid crystal is not sufficient, mulberry in the liquid crystal may precipitate (this dye precipitation occurs at low temperatures as described in the original paper). ), this may cause color unevenness in the display 11, resulting in further deterioration of display quality.

Therefore, to obtain the ideal dust-host wrinkled liquid crystal display device as described above, the dichroic dye mixed into the liquid crystal is: 1. A dye having a high dichroic ratio.

Elephant: It has high coloring ability, and a sufficient display color of member i5 can be obtained by adding a small amount.

3. It has sufficient compatibility with liquid crystals and does not cause precipitation even at low temperatures.

It is necessary to use a dye that satisfies all three conditions, but the conventionally used benzene-based azo dyes, stilbene-based dyes, anthraquinone-based dyes, etc. cannot be said to satisfy all of the above three conditions. 4 was hot.

The invention of ζO was made in consideration of the actual situation in 1.
For the purpose, ζro has a high dichroic ratio and high coloring ability, and has a 1k compatibility with liquid crystal.
There are two companies, Jin and K, which provide excellent dichroic dyes for liquid crystals.

That is, the dichroic dye for @Ots crystals derived from ζO is a trisazo type dye represented by the following general formula.

[General formula]

R 噌 where, R + ID, )l, Hag f y, CN18CN%
OR, 81% CゎH2t+1, C112, +1 partially substituted with fluorine to form a nine-fluorinated nalkyl group, BO2C, dog, +1.102CゎH! m+I K, where part or all of the water volume in K is substituted with fluorine, alkyl compound k X Jl/ * xk group, 0C11H211
+1, IBCIHffi@+1.0 (C, Hz,) -0
-(C,I-+1'), (C!lH2゜)-0-(Cm
Hzm+t), QCOCBH2m+ 1, COC,H2
11+11e represents C00C@11z=+1'.

iim　a　,H%　CH8%　QC)b.

OR, or Ilg, where R4-R6 is
It represents either Hl() or Cm111m+1.

Edarashi, - and 2 represent positive O integers from 1 to 8.

ν represents a positive integer from 1 to 30.

This dichroic dye is applied to a negative display tie that has been horizontally aligned on the electrode substrate surface (for example, by OO oblique evaporation or by applying a liimide resin and rubbing with cotton cloth, etc.) and vertically aligned on the electrode substrate surface. It can be used in any of the nine types of dust-host crystal display devices by applying treatment (for example, coating with a silane compound) and adding an optically active substance to the liquid crystal. . This dichroic mm family has a high dichroism ratio, high coloring ability, and the necessary and sufficient display color can be obtained with a small amount of addition. However, by using these dichroic dyes that do not precipitate, a display with good contrast can be achieved, and the responsiveness to display driving is also good, and furthermore, the displayed color does not fade over a long period of time. It is possible to obtain a crystal display device.

The 011 dichroic dyes may be used alone or in combination of two or more, and may also be used in combination with other dichroic dyes or substantially orthotropic dyes. however,
It is necessary to keep the total amount of dye added to any pigeonhole within a range that does not affect the operation of the liquid crystal molecules, so the total amount of dye added to the liquid crystal should be 0.1~! It is desirable to set the weight to S weight.

In addition, the dichroic dye for liquid crystals represented by the above general formula can be prepared, for example, by dinoazotizing unsubstituted or various substituted 2-aminobenzothiazoles by a known method, and then adding aniline methanesulfonic acid or naphthylamine methanesulfonic acid. After a pulling reaction, the aminoazo compound was obtained by hydrolysis (with alkali), which was diazotized, and then α-naphthylamine and ! Pudding! After reacting, it becomes diazo and uses it as various forces, f-ler and force, pudding! It can be synthesized by a method of reacting to obtain the desired trisazo compound. This compound can be used in liquid column coumad and recrystallization.
It is refined into products.

Hereinafter, the II theory example of the ζO invention will be explained.

Examples of dichroic dyes for liquid crystals represented by the above general formula include those represented by the following structural formula.

(1) [Structural formula] (2) [Structural formula] [Structural formula] (4) [Structural formula] (5) [Structural formula] (6) [Structural formula] Next, the dichroic dye 04I property is I will explain about the case when it is used in liquid crystal display devices.

The 11th Qti liquid crystal molecules are arranged homozonically to form a nine-negative display tie (DI" host-attached liquid crystal display device). Between a pair of electrode substrates JJIJj bonded via a sealing material 11, a host liquid crystal 14 and dichroic dye IJ
is filled.

In addition, the inner surface of both electrode bases @JJ and JJ is
611), and the total thickness of the liquid crystal layer is ulon9. And both electrode substrates 11.11 have both bases horizontal 11. An external power source 1- is connected to the JI gate to apply an electric field. In addition, display both sides O electrode group 1 [JJO outside picture,
A polarizer is provided to increase display contrast, and the optical transmission axis of the F-o polarizing plate IFO is homogeneously aligned with the long axis direction of the crystal molecules and the dye molecules.

7) In the liquid crystal display device, the host liquid crystal 14 is made of IDH Chemical Co., Ltd. 7 (a nematic liquid crystal with positive electrotropy) and the dye of (1) above was used as the dichroic dye 15, this display device displayed a purple color when no voltage was applied. When a voltage of 32 Hm, 3 VC) is applied, the electric field applied part becomes colorless9, and the dichroic dye exhibits a maximum 1tliL value length of 573 mm and a dichroic ratio of 10.2 in the host liquid crystal. The display contrast of this display device is extremely good.Moreover, the dichroic dye has a very high coloring ability and can be used by adding just 0.7% by weight to the host liquid crystal. It was possible to obtain a clear purple display color, and the dichroic dye had sufficient compatibility with liquid crystals, and no precipitation was observed even at low temperatures.

Additionally, in a negative display type dust host IIIm crystal display device using the V-phenyl liquid crystal F7,
Above (2) to (9) (using the latest dyes), the dye in (2) showed a color change of 10.2 at a maximum collection liquid length of 605 mm, and the dye in (3) showed a maximum absorption length of ff. .

mtm, the dichroic ratio IQ, (I), the dye (4) has a maximum collection wavelength of 602w+m, the dichroism ratio of 11J, and the (aOIII dye has a maximum collection wavelength of 607a).
m, dichroic ratio 12. In both cases, the display contrast of the display device is extremely good.9 However, these dichroic dyes also have very high coloring ability, and the contrast with the host liquid crystal is very good. It also has excellent solubility. In addition, here we will explain the six types of dichroic dyes mentioned above.Not only these dyes*, but all of them expressed by the above general formula have the same performance. The reason is that two or more types can be used together to obtain the same effect.

8th WJ shows a dust host wave crystal display device of a white tailor lid, and an optically talkative substance is glued between a pair of electrode substrates 111 and 21 through a sealing material 21. Meeting host LCD 24 and two-color Ik! Ik family 2j is filled. Note that the inner surfaces of both electrode substrates 11 and 11 are subjected to a horizontal alignment treatment, and the total thickness of the liquid crystal layer is I.
It is OA. Then, both the electrode substrates 21° 22
, there is an external power supply 2 that applies an electric field between both bases @11.21.
– is connected.

White Tailor with Heavy Dust Hoth FI111I
In the K-crystal display device, as the host liquid crystal 24, the via-2L liquid crystal 7 (used in the display device of FIG. 1) is used as a K optically active substance. 3 weights of nomiphenyl was added, and the dichroic brass material of (6) above was used as the dichroic dye 21. When no voltage is applied, it is colored one blue, and when a voltage of 32Bm and eVO is applied, the electric field application part becomes colorless.
) dichroic dye has a maximum collection liquid length of 1! 07 mwa,
It shows a dichroic ratio of 12.0, and the display contrast is extremely good.Moreover, the dichroic dye has a very high coloring ability and can be used as a host.
It is possible to obtain a display color of one blue' by just adding one weight by weight to the liquid crystal.

- At this one addition amount of the dichroic dye, the dichroic dye does not affect the operation of the liquid crystal.
The response of the display device to display driving is also good9.Furthermore, when the display device was left at a low temperature of -25°C and the precipitation of dichroic dye was investigated, no dye precipitation was observed even after 720 hours. No deterioration in the display quality of the display device was observed.

Note that the dichroic dyes that can be used in White Taylor-i's dust/homochrome crystal display device are not the same as the dyes in (6) above, but the dyes in (1) to (5) above. Similar effects can be obtained by using dyes such as the above dyes or other dichroic dyes represented by the above general formulas, and using a mixture of two or more dyes such as tortoise and oki.

Iris 31a shows a dust-host type liquid crystal display device of a nine-di display type in which liquid crystal molecules are homeotropically arranged, and is bonded via a sealing material 33 to nine pairs of O electrode groups*zx.
, sx are filled with a host liquid crystal 14 and a dichroic dye 3j. Note that the inner surfaces of both electrode groups @sx and sz are subjected to vertical alignment treatment II (orientation cutting is performed using, for example, octadecyltriethoxysilane), and the thickness of the liquid crystal layer metal body is 10 degrees. There is. Then, both electrode substrates 3
7, sx has both groups 1 [JJ.

An external power source 16 that applies an electric field is connected to the JJ cabinet.

In this host liquid crystal display device, as the host liquid crystal 34, the following chiral netite (as the ivy liquid crystal 36) is used as the optically active material. When the dye (4) was used, this display device was colorless when no voltage was applied), 32Hs, 3V
When a voltage of 591 cm is applied, the applied electric field is colored deep blue, and the dichroic dye exhibits a maximum absorption wave of 591 cm and a dichroic ratio of 10.5 in the host liquid crystal. The display contrast line of the display device was extremely good. Moreover, the dichroic dye has an extremely excellent coloring ability, and a deep blue display color could be obtained by adding only 2 weights of the dichroic dye to Phos-11.

Nine, the dichroic dye has sufficient compatibility with liquid crystals,
No precipitation was observed even at low temperatures.In addition, the dichroic dye used in this display type f (DI' host) liquid crystal display device, which is heated, leaks into the dye described in (4) above. (1) and (2) above.

(3) , (6) , (@) The same effect can be obtained even if 0 dye or other dichroic dyes represented by the above general formula are used, or if two or more of the 9 and 9 dyes are used together. is obtained.

[Brief explanation of the drawing]

The first iml is a negative display type r host type liquid crystal display design, and the second figure is a white taylor ma.
3rd IQ Hiro 4 Cross-sectional view of rst host crystal display device
The display type is 11 m [j & display scissors device disconnection i + osa. 11.12.21.12.31. JII2...electrode substrate, 11.13. IJ...Sealing material, 14°JJ, J
J... Host liquid crystal, 15.21.35... Dichroic dye, itt, xi, sg... External power supply, 11... Polarizing plate. Applicant's agent Patent attorney Suzue Takehiko Hikoyoko ill Hikoyoko 311 j4 j″3 jl

Claims (1)

[Claims] A dichroic dye for liquid crystals represented by the following general formula. [General formula] R" where: Ih Id, H, 80l"7, CN, gcN, 01
%811°CnHh+1, 01M21+I Part of the hydrogen in K is replaced with fluorine to form a nonafluorinated alkyl group, 1020@H2B-H1lQ2c@I! m+I
The water volume in K is partially or completely fluorinated in aluminum fluoride, where K is a hydrogen group, OCmH2m+1, gcI
In2II+t, 0(emHzm)-0-(CaHzm
+t), (Cs1gm)-0-(c,llHzm+t
), 0COC@H2vr+ 1, COC, HffiI
1〇㙸te represents C00C, Ilz@+r. Represents Isu, HSCal, OCIIM. /14 g x ■ 1, NgN-R4, Kanhiro, Do 1,
N1 Aya O Tsubasa 6 Kaiku represents 1114, this ζ is Rji4i#t,
H% @1. Represents either Cm12m+10. Edashi, *11! , Biji indicates Mu~5ojEo**・- is 1~
5oJEo** is shown.