JPS5825381A - Liquid crystal composition - Google Patents

Abstract

PURPOSE:A liquid crystal composition having an absorption band in the visible long-wave ray region and capable of efficiently absorbing a red ray, which contains a specified anthraquionone dye. CONSTITUTION:A liquid crystal composition contg. an anthraquinone dye of formulaI[wherein R1 is phenyl of formula II (wherein R5 is straight-chain or branched alkyl, alkoxy or halogen), biphenyl of formula III (wherein R6 is the same as R5) or cyclohexylphenyl of formula IV (wherein R7 is the same as R5); R2 and R4 are each hydroxy or amino; R3 is hydroxy, amino or alkylamino] and/or at least one anthraquinone dye of formula V[wherein phi1 is phenyl of formula VI (wherein R8 is straight-chain or branched alkyl, alkylamino or halogen); R9, R10, R11 and R12 are each hydroxy, amino or alkylamino; phi1 is placed at a position adjacent to R9 or R10; phi2 is H or phi].

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal composition that has an absorption band in the visible long wavelength region and can efficiently absorb red light.

Most liquid crystals are colorless. Although a small number of them are colored, none have an absorption band in a long wavelength range that can absorb red light. Liquid crystal displays have been developed as black and white displays, typified by the twisted nematic type.

In recent years, there has been a growing trend to make this display color from both a functional and fashion standpoint, and in particular, so-called guest-host type displays based on a combination of dyes and liquid crystals have been attracting attention. In this method, the display characteristics are greatly influenced by the quality of the guest dye, and for this reason, research and development of dyes with excellent t-retention properties have been actively conducted, and as a result, 1.
In 2 years, practical products such as clocks that displayed red, blue, black, etc. appeared. However, when compared with the existing Ike's display, the display quality, such as contrast and vivid colors, is at a mediocre level, and this seems to be a major factor that is holding back the dramatic development of color LCDs. This is particularly noticeable in black display, which is the basic tone of color liquid crystal displays, and the actual situation is that there are no displays that display a black color that looks like black, except for a very small number of -1 displays. In other words, the location where the display will be used, such as indoors or outdoors, the difference in light sources such as sunlight, fluorescent lights, red lights, etc., and the difference in illuminance between daytime and twilight even under the same sunlight, the location where the display will be used, the light source,
There is a drawback that the displayed colors look different depending on the state etc. The biggest reason for this is that it has to absorb enough red light, which is necessary to produce black color, and has other properties (solubility, stability, dichroism, etc.) necessary for use as a liquid crystal composition. The reason lies in the absence of dye. The dye that can efficiently absorb red light is a so-called blue dye, and preferably has an absorption band in the range of 600 to 7501 m.

At present, various dyes have been developed, and if selected from this viewpoint, the following blue dyes may be mentioned.゛Known dye 1 (R is a substituent) Known dye 2 Known dye 1 contains wn (Chloroform) 620-625
nm, and even in liquid crystal it shows a red shift of at most 20nI11, 700-? There is little or no absorption of red light in the 25In region, and only a black color like maroon can be produced. Further, the known dye 2 is a dye according to the invention of the present inventors, but this dye is
(Chloroform) exhibits a wavelength of 680 to 5 nm, exhibits a red shift of approximately 20 nm in various liquid crystals, and is an excellent dye for producing black color. However, this material has insufficient compatibility with liquid crystals, and has the disadvantage that its range of use is limited.

In view of the current situation, the inventors of the present invention have decided to
The present invention was completed as a result of intensive research to develop a dye that can sufficiently absorb colored light and has excellent compatibility and stability with liquid crystals.According to the present invention, red light can be efficiently absorbed. It is possible to provide a liquid crystal composition that is useful as a black display, a filter, a shutter, etc. because it can absorb into the liquid.

The present invention relates to one or two types of anthraquinone dyes represented by the general formula [■] and/or the general formula (1).
and one or two anthraquinone dyes αF represented by
The present invention relates to a liquid crystal composition containing one or two types of anthraquinone dyes represented by and/or the general formula [1].

In the L formula, R is a phenyl group represented by the formula ◇
A biphenyl group represented by 6 or the formula @(E>-R7
represents a cyclohexylphenyl group represented by The symbols R,, R, and R2 represent a linear or side-chain alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, an alkylcarbonyloxy group, or a halogen. R,, R, represents a hydroxy group or an amino group, and R8 represents a hydroxy group, an amino group, or an alkylamino group. φ represents the formula ◇XR8, and R.

represents a straight-chain or side-chain alkyl group, an alkoxy group, an alkylamino group, a realkylamino group, an alkylcarbonyloxy group, an alkoxyluponyloxy group, an alkoxycarbonyl group, or a /Xlogeno group. This phenyl group may have a lower alkyl group, an alkoxy group, or a /''trogen in its vacant position.R,,R,.,R11
% RI2 represents a hydroxy group, an amine group or an alkylamino group, at least two of which are amino groups or alkylamino groups, and at least one of which is an alkylamino group. Mat: φ1 is R1, R1
Any adjacent position of ゜ may be used, and φ2 represents φ1.

Next, typical dyes used in the present invention are illustrated. It goes without saying that the present invention is not limited to these dyes.

The dye corresponding to the general formula [■] can be manufactured as follows, for example, with respect to dye number 1. That is, 1,5-dihydroxy-4,8-dinitroanthraquinone and barabutylaniline are reacted by heating at 100°C to 200°C in an inert solvent such as nitrobenzene, and the resulting 1,5-dihydroxy-4-p-butylanilino- 8-nitroanthraquinone in alcoholic water,
The crude product is obtained by reduction with sodium sulfide.

A pure product can be obtained by purifying this using a conventional purification method such as a column or recrystallization. Also, dye 6 is 1
．． It can be obtained in the same manner as Dye I by using 8-dihydroxy-4,5-dinitroanthraquinone as a raw material. Dye 8Fi is obtained by condensing 1,5-dihydroxy-4,8-diaminoanthraquinone and paranonyloxyaniline in alcohol in the presence of poric acid. Dye 10゜18 is produced by reacting the leuco form of 1,5-dihydroxy-4,8-diamino-2-(parahebutyloxyphenyl)-anthraquinone with ethylamine, followed by oxidation reaction with an oxidizing agent such as nitrobenzene. It is obtained by separating and purifying the resulting reaction product. Dye 11 can be obtained by reacting 1,5-dihydroxy-4-amino-8-hebutylamino-anthraquinone and hebutyloxybenzene in sulfuric acid in the presence of manganese dioxide and boric acid, and converting the boric acid ester by a conventional method. Obtained by decomposition. Dye 12 was prepared by reacting 1,4-dihydroxy-5,8-diethylaminoanthraquinone with hebutyloxybenzene in sulfuric acid in the presence of manganese boric acid, and treated in the same manner as dye 11 to obtain a crude product. A pure product can be obtained by purification using the method of purification. By adopting any of these methods,
The dyes of the general formulas CI) and [CI] used in the present invention are obtained.

These dyes have an absorption maximum of 640 in chloroporum.
It is in the long wavelength range of nmμF and can efficiently absorb red light. Therefore, by adjusting the color of one or two of these dyes, cth, with dyes in other wavelength ranges, it is possible to achieve the desired black-like display. Furthermore, when dyes of general formulas [I), CI), and [1] are used in combination, it is possible to create a blacker black color because it efficiently absorbs light in the wavelength range of 600 to 750 old n. . It can also effectively transmit or block light of 600 to 750 nm. I would like to add that 65-
By mixing the dye of the present invention with a wavelength of about 700 or 650 nm and a yellow dye, a vivid green color can be produced, and by appropriately mixing the dye of the present invention with a wavelength of about 700 or 650 nm with a yellow or red dye, a blackish black can be produced. colored. The dye used in the present invention is an anthraquinone dye, which has excellent photostability. It also shows sufficient solubility for use in various liquid crystals, such as biphenyl liquid crystals and phenylcyclohexane liquid crystals. Historically, it is a group of dyes that have dichroism, which is an element such as contrast, and has values that can be used practically. To further explain these with specific examples, for example, dye 1 has a dichroic ratio of 5.5 in biphenyl liquid crystal, dye 13 has a dichroic ratio of 5, and dye 10 has a dichroic ratio of 5.9. Although these values are slightly lower than the currently required dichroism ratio, it is possible to produce black that is black, that black that is black cannot be produced with existing dyes, and that the demand for black is extremely large. Even with these values, the residual color in the blue region is relatively unnoticeable compared to other colors even with a dichroic ratio of this level, and does not degrade display quality. It can be said that the dye used in the present invention can sufficiently achieve its purpose. Dye 3.4 has higher dichroism than Dye 1, and can achieve dichroism of 7 or higher. Dye 2 also shows a larger value than Dye 1. Furthermore, dye 12 exhibits greater dichroism than dye 13, and dye 11 exhibits dichroism similar to or slightly better than dye 10. dye 1
．． 13, 1O is 6 in phenylcyclohexane mixed liquid crystal
．． The dichroic ratios of 5, 5, and 6.4 are shown, respectively. Moreover, the solubility at room temperature is 2 wt% or more.

According to the present invention, it is possible to display black-like black (even green and other toned colors) regardless of the place where the display is used, the light source, the conditions, etc., so it is possible to display high-quality audio and other indoors. It is possible to provide consumer electronics, outdoor displays for automobiles, optical gloss, etc., and it will greatly contribute to the progress and development of color liquid crystal displays by improving the χ point of today's color liquid crystal displays.

H crystal Id Not only hyphenyl type and phenylcyclohexane type but also ester type, Schiff type and others are significantly used. Also nematic, cholesteritic nematic,
Smectic liquid crystals are also applicable.

As the display method, any method based on the positive or negative dielectric anisotropy of the liquid crystal can be adopted.

Patent Applicant Co., Ltd. Japan Photosensitive Pigment Research Institute Procedural Amendment - (Method) % Formula % i 4th person liquid crystal of working beak Yoso MasaO content patent FGK and specification O engraving (content Km additional 1kL) Al
l) Attachment amount l) Time review and engraving of detailed statement

Claims (1)

[Claims] [In the formula, R1 is the formula ◇) -R, (R is a linear or side chain alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, an alkylcarbonyloxy group, or a halogen phenyl group (which may have a lower alkyl group, alkoxy group or halogen in the vacant position) represented by the formula ()-(R-R, (R, is R6
represents a biphenyl group represented by the formula &R, (R represents the same substituent as described for R3), or a cyclohexylphenyl group represented by the formula &R, (R represents the same substituent as described for R3), %R4 represents a hydroxy group or an amino group, R1 represents a hydroxy group, an amino group or an alkylamino group] and/or an anthraquinone dye represented by [wherein φ1 is the formula ◇)-R, (R is a direct The chain r represents a side chain alkyl group, an alkoxy group, an alkylamino group, a dialkylamino group, an alkylcarbonyloxy group, an alkoxycarbonyloxy group, an alkoxycarbonyl group, or a halogen. group, alkoxy group or halogen), R,, R,. , R, , R, 2 represents a hydroxy group, an amino group or an alkylamino group, at least two of which cJ, h are an amino group or an alkylamino group, and at least one of them represents an alkylamino group. The expression,φ,is R,,R,. Liquid crystal composition 2 containing one or two αE anthraquinone dyes represented by ■ (or φ1) may be at any adjacent position, and φ2 has the general formula [glue] [where R11, RI4, R16 R1 is a μ-droxy group or an amino group, and φ1 is a phenyl group (which may have a lower alkyl group, alkoxy group, or halogen in the vacant position) represented by φ2 represents H or φ1] (symbols are the same as above) and/or anthraquinone dyes represented by the general formula CI] (symbols are the same as above) or a liquid crystal composition containing two or more types.