JPS58142960A - Liquid crystal composition - Google Patents

Abstract

PURPOSE:To provide a liquid crystal composition containing specific ester compounds and a chiral nematic liquid crystal at specific ratios, exhibiting quick responce even at a low voltage, having broad temperature and voltage margins and high chemical stability, and suitable for a liquid crystal light valve of a printer. CONSTITUTION:The objective composition is composed of (A) a mixture of ester compounds comprising 40-60wt% compound of formulaI(R and R' are 1-8C straight-chain alkyl), 0-20wt% compound of formula II, 0-20wt% compound of formula III, 5-20wt% compound of formula IV and 0-15wt% compound of formula V (group of formula VI is formula VII or formula VIII) and (B) 0-5wt% chiral nematic liquid crystal. A liquid crystal panel suitable as a liquid crystal light valve for the optical ON-OFF control can be manufactured by inserting the liquid crystal composition between a pair of oppositely placed glass plates each having a NESA electrode at the inner side. The ON-OFF control can be carried out by applying a signal containing a component having higher frequency than the cross frequency (fc) of the liquid crystal material and a signal containing lower frequency component than fc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides optical 0N- 01FF control liquid crystal light pulp Kll. Further, by using a new liquid crystal composition, the light response speed of the panel can be greatly increased.

In recent years, there has been rapid progress in increasing the capacity of information processing, increasing the speed of calculations, and popularizing office automation equipment. Printers, which are one of the terminal devices for office automation, are also required to be high speed, 4 print quality, and low price, but there are currently no products on the market that satisfy these requirements. There is no rounding, so C output is strongly desired.

A printing device that uses liquid crystal light pulp as the signal generator and applies electrophotographic technology
A summary of the above points to a practical level.

I'm sweating.

First, optical writing λ is performed on the photosensitive drum 102 by the nine-light signal generating section 101 using the liquid crystal light pulp, as shown in FIG. At this time, the photosensitive drum 102 is charged in advance by a corona charger 110. At this time, when printing characters, the optical signal is usually such that light is generated corresponding to the character part. As a result, an electrostatic latent image is formed, and the toner Il1gII is applied by the magnetic pusher 105. In this case, the current salary method is usually reversed current salary. This firefly, transcription: r
The toner is transferred onto the plain paper 104 by the Rona electric device 105 and fixed by the fixing device 106 . The toner remaining on the transfer mIO photosensitive drum is removed by a blade 108, and the electrostatic latent image is neutralized by a static elimination lamp 109, and the process is completed.

Figure 2 shows the configuration of the light #9 generating section.The light emitted from the light beam 201 is turned ON-〇1 in the liquid crystal panel section (211 to 218).
1, and the transmitted light is passed through the polarizing plate 2 by the condensing lens 221.
11, KII on glass plate 212, spatter, dip coat, I! The liquid crystal 218 is held between the neta 1113 formed by the Kti7 etching, the metal thin @ 214 used as an optical mask, the absolute I# film 215, the W direction control of the liquid crystal 1I216 and the seal 217, and the liquid crystal panel. ing.

The ssth is the positive # diagram of the liquid crystal panel, and the transmission of light, Jll
It consists of a micro-shutter 1pF 302 that performs the 1st function and a light 1 screen section 501 that always blocks light.

Next, the driving principle of liquid crystal light pulp will be explained.

411th Fi shows signals applied to the liquid crystal panel and transmitted light characteristics. However, what is shown here is Dyna 1
This is a case of driving by 1. When a large signal with high frequency components is applied to the liquid crystal display for a short period of time, the panel transmits light.
I a)) *Next, when a signal with a frequency component lower than that of the liquid crystal K fc is applied during the period [#14 Fig. 6)) the panel directs the light. 〒aFi--any selection period, and in this case, the data is #'iT4/TE. It is already known that the alignment of liquid crystal molecules can be controlled by the frequency of the applied signal, and the details are omitted here, but this phenomenon is explained by the fact that the sign of the dielectric anisotropy of the liquid crystal depends on the applied signal. It is based on the property of being inverted depending on the frequency. Figure 5 shows the dielectric constant C in the long axis direction of liquid crystal molecules and the dielectric constant C in the short axis direction.
It shows the frequency dependence of 5. Crossing frequency feC also =
The driving layer 11 of the liquid crystal light pulp has been described above, in which the sign of the dielectric anisotropy Δ- is reversed based on the frequency at which the dielectric anisotropy is -. When used for printing, high speed printing equipment, high print quality,
PK is the ninth type of KFi that achieves high reliability. First, high optical energy must be applied to the photosensitive drum within 4 hours of writing (48th!0th A). In order to satisfy this requirement, it is of course possible to improve the light source optical system around the panel and drive method to some extent, but the basics of liquid crystal A lot depends on the characteristics. The following items are listed as the basic characteristics required of the rounded KW1 crystal material to realize excellent 9-LC light pulp.

High-speed response at low voltage.

2.11 change, the voltage margin is wide.

Examine the cost by ensuring compensation.

2-frequency liquid crystal material, department for display use.

Research has been done in the past, and an excellent one has been published, but Imprint 1
Very fast response (several 4V seconds or less) like the liquid crystal light pulp used in 1fK 11! Research has yet to find out what is required, and there are not many liquid crystal materials that satisfy all of the characteristics mentioned above. It is a material with added features, and its purpose is to provide high-speed response at low voltage.

2. Wide temperature and voltage margins.

To be able to secure technical high school-Italy characteristics.

2 1i1 & jkm that satisfies ON Kyo in a well-balanced manner
Our purpose is to provide liquid crystal materials for use in liquid crystals.

Below, we will explain these requirements.

t High-speed response with low voltage.

Driving circuit KIO for smaller size of completed unit and lower cost
When using the pedestal, the driving voltage, the driving layer A1, and the upper jI
I is constrained. Furthermore, in order to reduce power consumption, low voltage and low frequency are desirable.
It is necessary to increase the absolute value of dielectric anisotropy at . Large and low viscosity is also required. l! Since the driving frequency cannot be made very high, fc at the operating temperature must also be set appropriately low.

The liquid crystal material that satisfies these requirements with a single component is I/larger than 1.
By mixing several components, each characteristic can be satisfied in a well-balanced manner. First 1. (a, viscosity O adjustment,
These two have contradictory properties. Among the components in the composition provided by the present invention, R-Gf)-000-OR' [where R and R' are 1
~8R- [Yes] @-c o obe Q-R' 110
Naoto-kuni-o-o-p-R' with a rotational element
[representing chain full kill] has the property that both fc and viscosity of the composition are low to a practical level.Next, in the component chain that adjusts the dielectric anisotropy at low frequency, a high frequency number is added. It is a component that adjusts the dielectric anisotropy in the liquid crystal, but it is a fake liquid crystal or liquid crystal and S4! Among the compounds having the molecular structure i, there are many compounds with a large absolute value of positive dielectric anisotropy, but there are very few compounds with a large absolute value of negative dielectric anisotropy. , - Solution entropy is a quibble, liquid crystal temperature variation model! If l is wide, and further Kfdfc and t/lll5lf'1 constraints are imposed that do not adversely affect the viscosity, the types will be further limited. , R represents a straight chain alkyl having 1 to 8 Il of divalent atoms] has a very large positive dielectric anisotropy, and also has a low fc,
In addition, in the components of the lateral eyelids, R-(-0-)-@-oosovoof [However, B represents a straight-chain alkyl having 1 to 8 pedicles. In the structural formula, (() represents either Φ or Fi)] d1 The absolute value of negative dielectric anisotropy is large and the compatibility with other components is excellent.

Next, regarding the chiral nematic liquid crystal among the components of the composition provided by the present invention! In the case of summer display panels, we have added a small amount of wrinkle component to prevent reverse tilt, a KN for guest-host display to improve contrast, and a friend display method by applying the memory effect of the liquid crystal with scissors added. Many examples of the use of this ingredient in buds are known. '*Tanaka Ki! It is also well known that the response speed is improved by utilizing the helical force of chiral nematic liquid crystal, that is, the force of returning it to a helical structure. , there is an effect similar to that described above, that is, an effect of improving response speed. In the 2-frequency 41111 system, fc
Driving using a signal having a higher frequency component, that is, aligning the liquid crystal molecules square to the cell image, has the effect of significantly increasing the speed.

The authors have proposed that by combining the above-mentioned components in appropriate proportions, the absolute values of Δ#mu and Δ#rich (especially the absolute value of Δ1 irises in vertical vm compositions can be greatly increased). However, by adding chiral nematic liquid crystal to -1, we were able to dramatically increase the response stray electricity at the voltage used! However, in the case of liquid crystal compositions, it is predicted that the interaction between different components will have a considerable influence on the viscosity, e.g. In the composition provided by the present invention as well, this interaction seems to work in the direction of improving the stability of the composite, but there are no speculative or quantum mechanical theories on this point. I look forward to future research on this topic.

The above is the first example of using the component according to the present invention to achieve characteristic 1.

2. Wide temperature and voltage margins.

First, regarding the temperature margin, the temperature dependence of the dielectric anisotropy of liquid crystal is shown in chick 6@, in aa.

ΔIL is the dielectric anisotropy at a low driving frequency, and ΔII is the dielectric unidirectionality at a high driving frequency. As you can clearly see, Δ-iris decreases rapidly as W rises.

Although there are some differences in the LCD of this +5F11I,
Since this is a basic characteristic of liquid crystals, when using actual 1IIK, it is necessary to select a temperature range in which the amount of W change in ΔIII is small. In some cases, it is necessary to lower the viscosity of the liquid crystal once in the bulk temperature range. Based on the fact that it is undeniable that the temperature difference is driven to a large extent by the temperature change, and in order to maintain a wide temperature margin, the light transmittance 411!1 of the Il insect must be saturated. There are l1ls
It is necessary to adopt This means that under a constant voltage, the response is fast and the transmission is saturated.
By doing so, it is assumed that the above-mentioned characteristic 1t#1 is added. Furthermore, the same consideration can be given to the voltage margin.

'EL　＾ Must be able to ensure reliable noodles.

Many studies and 11 experiments have been conducted regarding the chemical, optical, and chemical stability of liquid crystals.The liquid crystals according to the present invention are all ester-based liquid crystals. Furthermore, due to accelerated aging and other factors, the reliability has been evaluated as being at a practical level for optical spectroscopy.

In order to clear the above-mentioned 41 items 12 and 5 in a well-balanced manner and at a practical level, the present invention creates a high performance crystalline material with excellent properties as a composition by appropriately selecting the proportion of each of the above-mentioned components. I was able to make it. -r that is 1
The composition is as shown in IIK.

[Ebo, in Ea above, R and R' represent straight chain alkyl having 1 to 8 leg atoms, and (-0-)V in the structural formula
(ah) either i, -〇- or 〇〕11 Next, the details of the present invention will be explained with reference to examples.

The liquid crystal composition listed in Example 112 was combined and its basic properties and light transmission properties tWI4 were determined.

lI! 2 Acupuncture [However, Oa Hlf in the table has an arc structure] Shows the frequency dependence of the dielectric constant of the liquid crystal composition shown in No. 711Kl12, provided that the constant temperature #i is 50°C.

This liquid crystal T can withstand low frequency signals (isOV, IKHI) and high frequency signals 4 (5Qv) in a test cell with a cell thickness of 5.1 liters.

150K11g) was driven on an H dyna, and the light transmittance range shown in No. 6 was obtained. 11
In 1 Yosho and Idaina 1 ivy drive, the repetition period is t
4~t @ mam, - date and time @ (L 4 % (15
On a Mac, you can use strange blocking responses. (UL, the two pin angles of the nine cells used at this time were Fi70@, and the polarizing angles of the polarizing plates sandwiching the cells were set at right angles to each other.The measured hot injection temperature was #0 at 40°C.

Next, a printing experiment was conducted using this liquid crystal light pulp. The liquid crystal light source used is the same as the illumination type 4 described above, the driving conditions are also the same, and the light source has the structural formula as M17 A.
11on: Using the phosphor of Te♂1, sensitize the photoreceptor with a high-intensity fluorescent lamp with #i-d, and use 90-.

As shown in FIG.
f8 movement speed * ii5 ex/see. By driving the liquid crystal light pulp, it was possible to write a memorandum, and it was possible to form a clear calligraphy corresponding to the oy-opv. This embodiment is an example of the use of the liquid crystal light pulp provided by the present invention, and is applicable to Tol+, optical writing feed at other than printing molds, and display #.

Book IJ again! The liquid crystal composition used in the koji example is an example. Even if each component was replaced with its homolog Kf#, the blending ratio was 1,000,000. Even within the range of , the same excellent sIK characteristics as in this example are obtained! The present invention is not limited to this embodiment, since the present inventor has already experimented with what is possible.

As stated above, in the zero release, we use the dielectric dispersion of liquid crystal,
By using liquid crystal light pulp KTh, which uses two armpit drives for positioning and high-speed switching, we have succeeded in demonstrating the responsiveness of the liquid crystal material, and have been able to improve the printing capacity even during IK. The effect of the present invention is significant because the voltage margin can be dramatically improved.

[Brief explanation of drawings]

Part 1m is a structural diagram of a liquid crystal light pulp type printing device. The second m is a schematic diagram of liquid crystal light pulp. sli is the liquid crystal used for the liquid crystal light pulp (upper surface of the panel). Figure 4 shows the signals applied to the liquid crystal light pulp and the O
It is photoresponsive to IF411. Figure 5 shows the frequency characteristics of the dielectric constant of liquid crystal. Il[Figure 6 shows the iI variation of dielectric neutronics of liquid crystal. 7th Ii+ is the dielectric and modulus frequency characteristics of the nine liquid crystal condensates used in this example. No. 8I11 shows the photoresponse characteristics of the liquid crystal light pulp according to this example. That's all, Suwa Seikou Co., Ltd. Item 1, Figure 2, Figure 3, Figure 4, Figure 7

Claims (1)

[Claims] A liquid crystal panel in which two glass plates each having a Nesa electric grid on the inside are placed facing each other and a liquid crystal material is sandwiched between them has a frequency component higher than 1 (hereinafter abbreviated as fc) of the liquid crystal material. In the liquid crystal control study #IF, the intensity of transmitted light is controlled by applying a signal having a frequency component as low as fc and a signal having a frequency component as low as fc, singly or in combination, to control the intensity of transmitted light. A liquid crystal composition having the following composition: [In the structural formula, (() ) is Banmae represents one of the states of coma.]