JPH02178390A - Liquid crystal composition and display element using same composition - Google Patents

Abstract

PURPOSE:To obtain a color liquid crystal composition having especially excellent light resistance, further contrast and life, containing a liquid crystal substance and four kinds of anthraquinone-based two-tone dyestuffs. CONSTITUTION:The aimed composition containing (A) a liquid crystal substance and (B) (i) one or more of anthraquinone-based two-tone dyestuffs shown by formula I (R<1>-R<3> are H, halogen, alkyl, etc.; A is group shown by formula II- formula IV, etc.), (ii) one or more of anthraquinone-based two-tone dyestuffs shown by formula V (R<4> is H, halogen, alkyl, etc.; X<1> is H, halogen, carboxylic acid ester, etc.), (iii) one or more of anthraquinone-based two-tone dyestuffs shown by formula VI (R<5> and R<6> are H, halogen, alkyl, etc.) and (iv) one or more of anthraquinone-based two-tone dyestuffs shown by formula VII (R<7> and R<8> are H, halogen, alkyl, etc.).

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a liquid crystal composition and a display element using the same;
In particular, the present invention relates to a color liquid crystal composition and a display element having excellent light resistance.

(Prior Art) A display element that utilizes the guest-host effect of adding a dichroic dye to liquid crystal has 1) a wide viewing angle. 2) A variety of display colors can be easily realized by selecting dyes. 3) Since it does not necessarily require a polarizing plate, it can provide a bright display, and is therefore attracting attention as a display element particularly suitable for medium to large-sized displays.

(Problems to be Solved by the Invention) Conventionally, however, it has been difficult for display elements that utilize the guest-host effect of adding dichroic dyes to liquid crystals to simultaneously satisfy high contrast, long life, and a variety of hues. The reason for this is that in addition to the lack of dichroic dyes that have excellent both dichroism and light resistance, when different types of dyes are combined, the photodegradation of one of the dyes, especially that caused by ultraviolet light, often accelerates. This results in lower light resistance than when the dye is used alone. There is a problem in that the deterioration caused by light that occurs in this way is observed as discoloration or fading, and is measured as an increase in current consumption. Therefore, conventionally, for various hues such as black, brown, dark blue, etc., it is necessary to mix yellow, red, and blue dichroic pigments.
In particular, there was a problem in that it was difficult to achieve both contrast and long life. An object of the present invention is to provide a color liquid crystal composition and a display element that can solve the above-mentioned conventional problems.

(Means for Solving the Problems) The present invention relates to a liquid crystal composition that is excellent in both contrast and life. That is, the present invention relates to a liquid crystal material and the following general 2(1) 1?2 +1-A-S.

(In the formula, Rl and R3 represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxyalkyl group, an alkoxy group, or a cyclohexyl group which may have an alkyl group, and A represents an anthraquinone type.) At least one dichroic dye, -1(II) (wherein R4 represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxyalkyl group, an alkoxy group or a cyclohexyl group which may have an alkyl group, represents a hydrogen atom, a halogen atom, or a carboxylic acid ester group that may have a substituent.)
At least one type of anthraquinone dichroic dye represented by the general formula (III) (wherein R5 and R6 may have a hydrogen atom, a halogen atom, an alkyl group, an alkoxyalkyl group, an alkoxy group or an alkyl group) At least one anthraquinone dichroic dye represented by the formula (IV) (in which R? is a hydrogen atom, a halogen atom, an alkyl group, an alkoxyalkyl group, an alkoxy group) or a cyclohexyl group that may have an alkyl group, and R8 is substituted with a hydrogen atom, a halogen atom, an alkyl group, an alkoxyalkyl group, an alkoxy group, a cyclohexyl group that may have an alkyl group, or an alkyl group or an alkoxy group. A liquid crystal composition characterized in that it contains at least one kind of anthraquinone dichroic dye represented by (a phenyl group that may be The gist of the invention is a display element supported on a substrate.

To explain the present invention in more detail, the general formula [I] ~ (
R I, R? on TV) As, a hydrogen atom;
Halogen atoms such as fluorine, chlorine, and bromine atoms - straight-chain or branched alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, nonyl, and dodecyl groups Group; methoxymethyl group,
Linear or branched alkoxyalkyl groups such as butoxymethyl group, methoxypropyl group, ethoxyethyl group, butoxyethyl group; straight chain such as methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group, octoxy group, etc. Cyclohexyl which may have a linear or branched alkyl group such as a cyclohexyl group, a propylcyclohexyl group, a butylcyclohexyl group, a pentylcyclohexyl group, a hexylcyclohexyl group, an octylcyclohexyl group; Examples of x+ in the general formula (I[) include hydrogen atom; halogen atom such as fluorine atom, chlorine atom, and bromine atom; methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group, octylcarbonyl group, etc. alkoxycarbonyl groups such as butylphenoxycarbonyl groups, octylphenoxycarbonyl groups, butoxyphenoxycarbonyl groups, phenoxycarbonyl groups that may be substituted with alkoxy groups, trans-4-butylcyclohexyloxycarbonylcyclohexyl Examples include linear or branched alkyl groups such as oxycarbonyl groups, carboxylic acid ester groups that may have substituents such as cyclohexyloxycarbonyl groups that may be substituted with alkoxy groups, etc. , in the general formula (IV) shown above, R11 is a hydrogen atom; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, Straight chain or branched alkyl groups such as nonyl group and dodecyl group; straight chain or branched alkoxyalkyl groups such as methoxymethyl group, butoxymethyl group, methoxypropyl group, ethoxyethyl group, butoxyethyl group ;methoxy group, ethoxy group, propoxy group,
Linear or branched alkoxy groups such as butoxy, pentoxy, and octoxy groups; linear such as cyclohexyl, propylcyclohexyl, butylcyclohexyl, pentylcyclohexyl, hexylcyclohexyl, and octylcyclohexyl groups or a cyclohexyl group which may have a branched alkyl group; phenyl group, ethylphenyl group, butylphenyl group, octylphenyl group,
Examples include phenyl groups which may be substituted with alkyl groups or alkoxy groups such as butoxyphenyl groups and octyloxyphenyl groups.

In each of the dyes of the general formulas (1) to (IV), when having a substituted cyclohexyl group in the structure, trans-4
A -substituted cyclohexyl group is preferred.

As the liquid crystal substance used in the present invention, the following general (in the formula,
R9, RIO is an alkyl group, an alkoxyalkyl group, an alkoxy group, an alkylphenyl group, an alkoxyalkylphenyl group, an alkoxyphenyl group, an alkylcyclohexyl group, an alkoxyalkylcyclohexyl group, an alkylcyclohexylphenyl group, a cyanophenyl group, a cyano group, Halogen atom, alkoxycarbonyl group, alkoxyalkoxycarbonyl group, alkylphenoxycarbonyl group, alkoxyalkylphenoxycarbonyl group, alkoxyphenoxycarbonyl group, alkylcyclohexyloxycarbonyl group, alkoxycyclohexyloxycarbonyl group, alkylcyclohexylphenoxycarbonyl group group, cyanophenoxycarbonyl group,
halogen phenoxycarbonyl group, alkylphenylalkyl group, alkoxyalkylphenylalkyl group, alkoxyphenylalkyl group, alkylcyclohexylalkyl group, alkoxyalkoxycyclohexylalkyl group, alkylcyclohexylphenylalkyl group,
It represents a cyanophenyl alkyl group, and may have an optically active center in the alkyl chain or alkoxy chain. Also, R9, R
The phenyl group or phenoxy group in IO is a fluorine atom,
It may be substituted with a halogen atom such as a chlorine atom.

Moreover, X2 represents a hydrogen atom or a halogen atom such as ).7 element atom or chlorine atom. ) or a mixture thereof.

Further, the liquid crystal composition may contain additives such as an optically active substance such as cholesteryl nonanoate, an ultraviolet absorber, and an antioxidant.

The liquid crystal composition of the present invention can be prepared by dissolving the dyes represented by the structural formulas CI) to (IV) in the liquid crystal substance.
It can be easily adjusted.

A display element applying the guest-host effect by supporting the liquid crystal composition prepared in this way between electrode substrates, at least one of which is transparent [Masashi Matsuki 1 Ichiyoshi Kakuda, “
Latest technology of liquid crystals” Kogyo Kenkyukai 34 (1983) J.
L, Ferguson, SID 85 Diges
t 53 (1985), etc.).

〔Example〕

EXAMPLES The present invention will be specifically explained below using examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

In addition, in the following examples, the quality of dichroism is determined by the order parameter (S) of the dye compound obtained from the following formula.
Evaluated by.

Here, A, // and A are the absorbances of the dye for light polarized parallel and perpendicular to the alignment direction of the liquid crystal, respectively.

Specifically, the order parameter (S) is
This is a value that indicates the display contrast of a host type liquid crystal display element, and theoretically, as this value approaches 1, the degree of residual color in white areas decreases, and a bright and clear display with high contrast becomes possible.

Furthermore, the dyes used in the following examples are listed in Table 1.

In addition, all 4-substituted cyclohexyl groups are trans-4
-substituted cyclohexyl i Table bt.

Example 1 The following dichroic dye was used under the trade name ZL;l-1565 (E, M
A liquid crystal composition (1) was prepared by dissolving the liquid crystal composition in 100 g of a liquid crystal mixture containing a phenylcyclohexane compound as a main component (manufactured by ERCK).

Dye (1-1) 2.80g (f[-132,00g (I[l-1) 0.87g (IV-1) 0.40g (IV-9) 0.80g This was coated with polyimide resin and cured. Thereafter, a liquid crystal display element was produced by sealing a glass plate with a transparent electrode, which had been subjected to homogeneous alignment treatment by rubbing, into a cell having a gap of 9 μm and configured such that the alignment treated surfaces faced each other.

The order parameters (S) of this liquid crystal display element were calculated to be 0.74, 0.72 and 0.70 at 575 nm, 539 nm and 467 ns, respectively. As a result of carrying out a light resistance test using a fade meter (carbon arc light source) on a cell filled with liquid crystal composition -■, the hue change after 200 hours: ΔE"(L"
a"b" method) is 3 or less, and the increase rate of the current value is 1/1
0 (applied voltage: 5■, 32Hz) is 2.5,
In addition, each absorption peak (575nm, 539nm, 467n
The absorbance change of m) was 3% or less.

Example 2 A liquid crystal composition-■ was prepared in the same manner as in Example 1 except that the following dichroic dye was used as the dye.

Dye CI-3) (I[-2) (n-3) (III-3) (IV-2) (■-3) (■-4) 2, 20 g 2, 1 0 g 1.55 g 1. 35g 1, 33 g 0.20g 0, 30 g 0, 30 g (1'V-9) 1.05g (1'V-
10) 0.55g of the same liquid crystal display element was prepared in the same manner as in Example 1, and the order parameter (S) of this liquid crystal display element was calculated to be 573
0 nm, 536 nm and 465 nm, respectively.
．． They were 74.0°72 and 0.70. Liquid crystal composition
As a result of conducting a light resistance test on the cell filled with
Hue change after time: ΔEI (L″a″b″ method) is 3.
2 or less, and the rate of increase in current value I/Io (applied voltage: 5
■, 32Hz) is 2.4, and each absorption peak (5
The absorbance change at 73 nm, 536r++n and 465 nm was less than 3%.

Example 3 A liquid crystal composition -■ was prepared in the same manner as in Example 1 except that the following dichroic dye was used as the dye.

Dye Cl-4) 1.40g (1-5) 1.45g (1-63,60g (II-4), 36g (II-6)
, 45g (nl-2)
, 45gCl[I-4], 60g[l
”/-5), 57g (IV 6)
, 62g.A liquid crystal display element was prepared in the same manner as in Example 1, and the order parameter (S) of this liquid crystal display element was calculated.
and 0.73 and 066 at 470rv, respectively.
It was 9. As a result of conducting a light resistance test using a fade meter (carbon arc light source) on a cell filled with liquid crystal composition -■, the hue change after 200 hours was 2ΔE.
(L"a"b" method) is 3.7 or less, the rate of increase in current value 1/Io (applied voltage: 5■, 3211z) is 3.3, and each absorption peak (580 nm and 470 nm
The change in absorbance (nm) was 4% or less.

Example 4 The following dichroic dye was used under the trade name ZLI-1840 (E, ME
A liquid crystal composition -1 was prepared by dissolving the liquid crystal composition in 100 g of a liquid crystal mixture whose main component was a phenylcyclohexane compound commercially available as (manufactured by RCK).

Dye (1-732, 10g (1-8) 2.30g (II-1) 1.OOg (II-5) 1.20g (III-2) 1.00g C1"/-7) 1.OOg (IV -8) 0.50g (IV-11) 0.50g (rV-12) 0.50g (IV-13) 0.50g This was sealed in a cell in the same manner as in Example 1 to create a liquid crystal display element. did.

As a result of calculating the order parameter (S) of this liquid crystal display element, at 630r+m, 579nm, 541nm and 467nm, the order parameter (S) was 0.74.0.73.
They were 0.73 and 0.69. As a result of carrying out a light resistance test using a fade meter (carbon arc light source) on a cell filled with liquid crystal composition (2), the hue change after 200 hours: ΔE"(L"a1b1 method) was 3.7 or less,
Increase rate of current value ■/r, (applied voltage: 5■, 32Hz)
is 2.9, and each absorption peak (630 nm, 579
541 nm and 467 nm) absorbance change is 3%
It was below.

Example 5 A liquid crystal composition-■ was prepared in the same manner as in Example 4 except that the following dichroic dye was used as the dye.

Dye Cl-9) 2.50g (n-2) 0.40g (n-3) 0.35g [[1-7) 0.42g (m-5) 0.66g (III-6) 0.75g ( IV-10) 0.60 g (IV-14) 0.70 g (IV-1530, 72 g Using these, a liquid crystal display element was created in the same manner as in Example 1.

As a result of calculating the order parameter (S) of this liquid crystal display element, 664 nm, 580 nm and 46'lnm
were 0.74, 0.73 and 0.68, respectively. As a result of carrying out a light resistance test using a fade meter (carbon arc light 'tX) on a cell filled with liquid crystal composition -■, the hue change after 200 hours: ΔEe
(Lm a$ bm method) is 3.5 or less, and the rate of increase in current value I/Io (applied voltage: 5V, 32Hz) is 3.8
, and each absorption peak (664 nm, 580 nm,
The absorbance change at 467 nm) was 4% or less.

(Effects of the Invention) As is clear from the above results, the color liquid crystal composition containing the specific combination of dichroic dyes of the present invention and the liquid crystal display element using the liquid crystal composition do not contain dichroic dyes. It takes advantage of the guest-host effect of the dye, and has excellent light resistance, especially for various hues such as blank, brown, and dark blue, which require the combination of yellow, red, and blue dichroic pigments. This has a remarkable effect of industrial value, making it possible to achieve both contrast and long life, which had been considered difficult.

Claims (1)

[Claims] 1) Liquid crystal substance and the following general formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼-[I] (In the formula, R^1 to R^3 are hydrogen atoms, halogen atoms, alkyl A represents a cyclohexyl group that may have a group, an alkoxyalkyl group, an alkoxy group, or an alkyl group; There is at least one type of anthraquinone dichroic dye represented by the general formula [II]▲mathematical formula, chemical formula, table, etc.▼-[II] (wherein R^4 is a hydrogen atom, a halogen atom, an alkyl group, an alkoxyalkyl cyclohexyl group which may have a group, an alkoxy group or an alkyl group, and X^1 represents a hydrogen atom, a halogen atom, or a carboxylic acid ester group which may have a substituent. At least one type of dichroic dye, general formula [III] ▲Mathematical formula, chemical formula, table, etc.▼-[III] (In the formula, R^5 and R^6 are hydrogen atoms, halogen atoms, alkyl groups, alkoxy At least one type of anthraquinone dichroic dye represented by an alkyl group, an alkoxy group, or a cyclohexyl group that may have an alkyl group, and general formula [IV]▲Mathematical formula, chemical formula, table, etc.▼ -[IV] (In the formula, R^7 represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxyalkyl group, an alkoxy group, or a cyclohexyl group which may have an alkyl group, and R^8 is a hydrogen atom, a halogen atom , an alkyl group, an alkoxyalkyl group, an alkoxy group, a cyclohexyl group that may have an alkyl group, or a phenyl group that may be substituted with an alkyl group or an alkoxy group). A liquid crystal composition comprising at least one of: 2) A liquid crystal display element comprising a liquid crystal composition supported between electrode substrates, at least one of which is transparent, characterized in that the liquid crystal composition according to claim 1 is used as the liquid crystal composition.