DE2351684A1 - VISION DEVICE WITH LIQUID CRYSTALS - Google Patents

Description

15, OHi 1HV3

LW / Xl / POS-3 2048

MATSUSHITA ELECTRIC. INDUSTRIAL CO., LTD., Osaka, Japan.

Display device with liquid crystals

The invention relates to a viewing device using liquid crystals. In particular, the invention relates an electro-optical, based on liquid crystals working display device, - in the case of the modulation of the · from A light source emitted light rays form a thin layer of hematic liquid crystals with constant molecular alignment is used.

The invention has for its object to provide a display device of the type mentioned, whose stability and efficiency is superior to the known display devices of the same type.

To solve this problem, a display device or a

409816/0956

Proposed display device, characterized by liquid crystals of the composition

CH ₃ (CH ₂ ) ₃ - ^ V-CH = N- ⁷ '> -CN

with a nematic structure at room temperature "

The new crystals used for the display are mainly characterized by a wide temperature range, in which the nematic state is retained. The new liquid crystals used were 4-n-butylbenziriden-4'-cyanoanilines thus enable the production of significantly more powerful viewing devices.

The invention is described below on the basis of exemplary embodiments. play described in more detail in conjunction with the drawings. Show it:

Fig. La shows a liquid crystal display structure

in plan view and

Fig. Ib shows a section according to Ib-Ib in Fig. La.

The figures show a typical structure for the visual display of information with the aid of liquid Crystals shown consisting of a first transparent substrate 1 with first transparent electrical Conductor layers 4,4 *, 4% as a coating on a, Surface of the first substrate are applied. A second transparent substrate 2 with a second light-permeable conductor layer 5 forms together with the substrate 1 an optical cell, which with the nematic

409816/0956. "

liquid crystals 6 is filled with »light that enters this cell occurs is with the help of an electric or a magnetic Field modulatable <,

The surfaces of substrates 1 and 2 and the conductor layers 4,4 * and 4 "as well as 5 can be treated as that the molecules of the liquid crystals at the phase interfaces are aligned in a preferred direction, while their longitudinal axis is parallel to the substrates and conductor layers stays aligned. In addition, polarizers not shown in the figures can be on each of the sides be attached to the display device, the polarization directions of which run parallel to one another or perpendicular stand on top of each other.

It is known from optical cells of the type described that the liquid crystals contained in them can be modulated _{under the control of a magnetic field or an electric field which is incident 4 from a light source.}

A number of applications have also become known for chemical compounds which are capable of forming liquid crystal systems. The optical devices for displaying information described by the known technologies have _# capable of forming such chemical substances a nematic liquid crystal system, is used. The viewing devices described so far are immovable built-in devices that work at very specific * temperatures, which are usually precisely maintained. For the extended applicability of such display devices, however, it is important that they are also used in mobile devices without meticulous temperature control at room temperature,

409816/09 50

so in the range of about 25 ⁰ C, can work. For the production of portable display devices, however, it is necessary that they do not require any complex temperature control to maintain precise temperatures of the liquid crystal system.

To practice the invention, a new chemical compound is used, namely 4-n-butylbenziridene-4-cyanoaniline the formula

^ -ff ^ -CH = N- ⁷ ^ -CN (A)

The transition temperature is for this new compound
from the crystalline state to the mesomorphic state
28.5 ° C and the transition temperature from the door mesomorphic state to isotropic liquid state at 51.8 ⁰ C.

Furthermore, a liquid crystal system consisting of various substances with a broad mesomorphic
Area can be obtained in a simple manner by adding compound A to at least one of the following substances:

409816/0956

0> CH = N (θ) CN

CN

CIL 0 (θ) CH = N

CH ₃ CH ₂ Q (O) CH = N (O) CN CH. (CH ₂ ) ₂ O {θ) CH = N (θ) CN CH ₀ (CHJ, O (θ) CH = N (O) CN CH ₃ (CH ₂ ) _k 0 <0) CH = N (5) CN

CIL (CHJ ^ O <O> CII = N (O) CN 5 ^ - J

O <O

CN

I 0 (Q> CH = N. (θ) CN

I _.

CH ₀ (CH ₀ ) ₀ C 0 (O) CH = N (θ) CN

.Q-

CH ₃ (CH ₂₎ C0 ^ @ CH- N (θ) CN

O
Qi ₀ (CHJ, CO (θ) CH = N (θ) CN

CH ₃ O <θ) CH = N (5) (CH ₂ ) ₂ CH ₃ ^! 3 '

CH ₃ (CH ₂ ) ^ O ® CH. = N ^ CCH ₂ ) ₃ CH ₃

CH 0 @ CH = N (g) (CH ₃ (CH ₂ ) ₂ O φ CH. = N.

(D (2)

(3)

0) (6) (7) (8)

(9)

(10) (11)

(13)

(16)

09 θ 16/09 56

The mixed liquid crystals having nematic properties obtained in this way are particularly liquid Crystal system in the electro-optical display devices, which work using the polarization effects, can be used advantageously.

To prepare the compound ä, 0.10 mol of p-n-butylbenzaldehyde were used and 0.1O mol of p-cyanoaniline in 500 ml of benzene refluxed in a 1 l round bottom flask for 4 h. The reaction flask was equipped with a reflux condenser, the upper open end of which with a calcium chloride tube was locked. A Dean-Stark trap was used to collect the seotropically removed water. After completion of the implementation under reflux, the solvent was removed under reduced pressure on a rotary evaporator. The residue was taken up and recrystallized from isopropanol.

The material obtained was recrystallized until its Melting point remained constant. Compounds 1 to 16 were prepared in the same manner.

There are a number of compounds with a nematic crystal structure known, which are relatively simple and are in the state of liquid crystals at room temperature. For these compounds, however, the temperature range is • in which they are in the nematic state, relatively narrow. For this reason, mixtures of different compounds have been studied to make a mixed system more fluid Crystals produce the state of liquid crystals not only in the range of room temperature or below have, but above all in an essential way wider temperature range than can be achieved for individual compounds. Examples of such mixtures of substances are compiled in Table 1 below.

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Table 1

; - ;. ■ Mixture compositions

CH ₀ CH ₀ O (θ) CH = N (θ) (CH ₀ ), CEL

9C

Wt%

(CHJ ₁ - 0 (θ) CH = N (θ) CH - CHCOOCH ₀ CH ₀ 10% by weight

^CH 3 O (θ) CH = N <O

.90

CH (CHJ ^ 0 (O) CH = N \ O) CH = CHCOOCH ₂ CH ₃

10

Wt%

. Weight %

CH ₀ CH ₀ O (O) CH = N (O) (CHJ ₀ CH - 3 2 VV v_ / 2. 3 3

Cd ₃ 0- (5) CH = N (θ) 0 CO (CH ₂ ) ₂ CH ₃

CH ₀ (CH _? ) O (5) CH = N (5) N = CH ./Ö) Oi

■■ egg

Wt%

_{Gew #} _ _{o / o}

CH (OH ₂ ) 0 (θ) CH = N (6) OCOCH ₀
CH ₀ 0 (Ö), CH. = N (5) OCO (CH _{2) 2} CH-.
Cli '. = "N (O) OC9CH-.

33.3

33.3

33

Wt%

Temperature range of
nematic state

22-77 ⁰ C

-15-115 ⁰ C

22-105 ° C

Table 1 (continued)

. Mixture compositions Temperature range of
nematic state

ο eo ot σ>

CH ₀ O (O) CH = N <0) (CH _o ) ₀ C:

J ^N ' ^V ' Q ^ J

CH 0 (0) CH = Ή (θ) OC (CH ₂ )

CH ₀ CCH ₀ ), C 0 <θ) COO (θ) OCH ₀ CH j ■ et -4 · ν- / v_y 'ii

2 mol 2 mol 1 mol

-3-8O ° C

CH ₀ (g) CH = N (θ) (CH ₂ ) CH ₀

Il __ ^

CH ₀ (CH ₂ ) 0 C (θ) COO (O) CH ₂ CH.

CH ₀ 0 ( 3rd

CH = N (θ) OCCH ₀

mixture

60 moles -

40 mol%

19-3O ° C

C "d _1? OCO (0) CH = N (Q) CN C ^ H ₁₀ O (Ö) CH = K (Ö) CW C) ₁ H _n O / oS CH = N <^> CN

1 mol 1 mol 1 mol

CD CX)

According to a particularly advantageous embodiment of the Invention is also the new compound A, which is itself extraordinarily, shows good nematic properties when mixed with correspondingly other suitable compounds. Examples for such mixed systems are summarized in Table 2 below.

Table 2

Composition Share in

Weight %

Temperature range of the nematic state - ( ⁰ C)

Connection A

Il
Il

75 25

80 2O

below 0 - 37.3

1! Ä 75 under O - 56.0 It 2 25th Il A. 75 23.0 - 67, 2 Il 3 25th

25.0-48.9

M. A. 50 13.2 - 75 _f 8 It 6th 50 Il A. 5O ■■ 14.0 - 79.0 S! 7th 50 ta A. 67 under 0 - 54.0 U -8th 33

4098 IS / 09 56

IC -

Table 2 (port setting)

Connection A 9

33 17 11.0-40.6

A 10

75 25 25.0 - 42.2

Ä 11

50

50 6.0-66.2

A 12

50 50 15.0-75.6

A 7 12

33.3 33.3 33.3 below -25 - SO, 6

Ά 5 6

33.3 33.3 33.3 below -25 - 83.3

A 5 12

50 25 25 below -25 - 76.1

A 5 7

33 _t 3 33.3 33.3 18, O - 36.6

13th

14th

33 _S 3 33.3 33.3 15.0 - 57.2

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Table 2 (continued)

Connection A 33, 3 20, 0 - 59 # 3 15th 33, 3 16 33, 3

In addition, the compound A or mixtures of the following organic substances are added to compound A with at least one of compounds 1 16:

(1) Pigment additives to produce a multicolored appearance, for example methyl red or indophenol blue and or or

(2) stabilizing additives such as hydroquinone or 2,4,6-tri-tert-butylphenol.

The aforementioned organic substances can be used as required be admitted. As already described, the vision device that comes with the use of the new liquid Crystals or crystal systems has been produced, its nematic properties in the optical cell over an extraordinarily wide temperature range including room temperature. The inventive Viewing device, which modulates the light coming from a light source, is suitable for practical use both in the industrial area as well as in the consumer area on clear advantages over the known devices.

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Claims (5)

Patent claims Γΐ.) A viewing device that works with liquid crystals, characterized by liquid crystals of the composition CH- (CH_) _-f J Z 3 \ - with a nematic structure at room temperature. 2. Viewing device according to claim 1, additionally containing an organic substance. 3. Display device according to claim 2, additionally containing at least one of the following compounds: 409816/0956 ₀ (CH ₀ ) _ο CO (Ö) CH = .Ν (θ) CN 3 - 2 έ ^ - ^J ^ - ^ ) V C O θ) CH "= N (O) CN CH ₀ (CH ₀ ), CO / θ) CH = N (θ) CN J ti D - __ CH ₀ 0 (θ) CH = N (5) (CH) _p CH _o CH ₃ (CH ₂ ) ₃ 0 ₂ ) ₃ CH = N (θ) (CH ₂ ) CH 0 (θ) CH = N (θ) (CH ₂ ) ₆ Cif ₃ CH ₃ (CH ₂ ) ₂ 0 @> CH. = N (θ) (CH ₃ (CH ₂ ) ₂ CH o S) CE = N <O> CN CH = N (θ) CN CH.CH. 0 @ CH = N = κ © CH ₃ (CH ₂ ) i _f 0 <O) CH> N -CH ^ (CH ₉ ). 0 (θ) CH = N @ CN CH ₃ (CH ₂ ) ₆ 0 <O) CH = N (Ö) CN CH ₃ CH ₂ CO (θ) .CH = N (O) CN 409816/0956 4. Viewing device according to one of claims 2 or 3, characterized in that the organic substance is a pigment additive for the multicolored display. 5. Display device according to one of claims 2 to 4 _# characterized in that the organic substance is a stabilizing additive. 409816/0958