JPS58142962A - 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 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 performs optical ON-OFF control by applying signals of a frequency component of FA and a frequency component of FE to a liquid crystal material held in a liquid crystal panel. Do liquid crystal light pulp Kll. ? By using a new liquid crystal component, the light response speed of the channel is extremely fast.

In recent years, there has been rapid progress in increasing the capacity of information processing, increasing the speed of calculations, and popularizing office automation devices. Printers, which are one of the terminal devices in the 0-frame computer, are also required to have high speed, high print quality, and low price, and at present, there are no products on the market that add these features. Its appearance is strongly desired.

Insho Soso (416 Pancreatic Introduction 56-955681
has received more attention than the actual level due to the points mentioned above.

First, an optical signal generator 101 using a liquid crystal light pulp generates an optical signal on a photosensitive drum 102, as shown in No.
You will be moved out. 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. This causes an electrostatic latent image to be formed and developed in a magnetic brush developer 103. The WE method at this time usually involves reversal development. The toner is transferred onto plain paper 104 by the transfer corona discharger 105 and fixed by the fixing device 106 . The toner remaining on the photosensitive drum after transfer is removed by a blade 108, and the electrostatic latent image is neutralized by a neutralizing lamp 109, and the process is completed.

Figure 2 shows the configuration of the optical signal generation section.
Under OFIF control, the transmitted light is imaged onto the photoreceptor by a condenser lens 221. The liquid crystal panel has two polarizing plates 2.
11, a glass plate 2121Kl1 (attached to sputtering and digging), a negative electrode 213 formed by photo-etching, a metal thin film 214 used as an optical mask, an extremely thin film 215, The liquid crystal 218 is sandwiched between the liquid crystal alignment control films 216 and 11, the seal 217, and the liquid crystal panel.

FIG. 3 shows the main 1WJ of a liquid crystal panel, which consists of a group of micro shutters 302 that transmit light and a light mask section 301 that constantly collects light.

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

The fourth @I shows the signal applied to the liquid crystal panel and the transmitted light characteristics. However, what is shown here is Maina lv.
It is a luxury when it is driven separately. When a signal with a higher frequency component than the liquid crystal K fc is applied for the duration TI [Fig. 4 b)], the panel transmits light (Fig. 4 III a)).
eNext, when a low-frequency component is applied to the liquid crystal Kfc, a signal of 4 times higher is applied (Fig. 4h))) The panel emits light tII.
Do IF+. ! 1 is a so-called selection period, and the duty in this case is 1/Ta. The frequency I of the signal applied in this way! Although it is already known that the alignment state of liquid crystal molecules can be controlled by controlling the orientation state of liquid crystal molecules, and the details are omitted here, this phenomenon is that the sign of the dielectric anisotropy of the liquid crystal is reversed (depending on the number of applied signals OII). Based on nature. No. 5111 shows the frequency dependence of the dielectric constant of liquid crystal molecules in the direction of the major axis and the dielectric constant in the minor axis direction. At the crossing frequency fe (~1 sudden frequency), the sign of the dielectric anisotropy Δ- is reversed and v
The above describes the driving and q theory of the liquid crystal light pulp, and 9. When used in the optical booklet insertion part of this liquid crystal light pulp printing device, high speed, high printing quality, l'
In order to achieve high reliability, many constraints must be met.Firstly, the writing time (
During the fourth step (S), high-temperature energy must be supplied onto the photosensitive drum.

20 In order to satisfy the requirement #i, of course, depending on the light source optical system around the panel and the drive method, 411! ! Improvements are possible to some extent, but much depends on the basics of liquid crystals. The ninth liquid crystal material Kl that realizes the excellent nine liquid crystal material Kl! The basic characteristics required are listed below.

t High-speed response with low voltage.

2.111t・Wide voltage margin.

Vessel: Ensure high credibility.

Liquid crystal materials for dual-frequency drive are being researched in the display industry, and some excellent products have been produced. Research on the materials that require the following) is still shallow, and there are not many liquid crystal materials that satisfy all of the above-mentioned characteristics.

111゜The present invention provides a liquid crystal light used for printing capacity cape,
'This is a liquid crystal material for pulp with improved characteristics.The purpose is to provide high-speed response at low voltage.

1114・Wide voltage margin.

5. To ensure high reliability of sea bream.

If we can provide a liquid crystal material for dual-frequency driving that satisfies the above requirements, we will be able to provide a liquid crystal material for dual-frequency driving.

Below, we will add an explanation to these requirements.

t High-speed response with low voltage.

Drive circuit KIO is used to make the finished product smaller and lower cost.
When a shoe is used, the driving voltage and driving frequency of the upper eyelid are limited. Low voltage and low frequency are also desirable for rounding to reduce WK power consumption. * Rounding is inversely proportional to the square root of dielectric anisotropy, as shown by crystal response speed f ij fd-・H.
To obtain high-speed response, it is necessary to increase the absolute value of dielectric anisotropy at #i drive frequency. 1! Also, the viscosity is low.
! required.

! FE is also suitable for use in large, hot jets where the KLL theory frequency cannot be raised too high! ! There is no liquid crystal material that satisfies these requirements with a single component.It is necessary to balance and satisfy each characteristic by combining the rounded and fractional components. First, fa and viscosity are adjusted, but these two have contradictory properties. Among the components in the composition provided by the present invention, F(-@-coo-@-OR' (where R, R'
Since it has 1 to 8R4D-@-c o o-@-1' diatomic atoms, it has the property that both the fo and viscosity of IM materials can be lowered to a practical level.

Next, the component that adjusts the dielectric anisotropy at low frequencies and the component that adjusts the dielectric anisotropy at high frequencies are known liquid crystals or compounds with a molecular structure similar to liquid crystals. There are many cases where the absolute value of the dielectric anisotropy is very large, but there are very few cases where the absolute value of the negative dielectric anisotropy is very large. Furthermore, in both cases, the melting end-beam is small, the liquid crystal temperature range is wide, and furthermore, fc, viscosity, K
If constraints such as no influence on M are applied, the species IIIFi becomes even more limited. It is large, and the height of the magnification is low.
It also has excellent compatibility with other ingredients. Among the components of the 11IK composition: [I, RF11-8 chain alkyl t1! [Wow] is a stone with a very large absolute value of negative dielectric anisotropy and excellent interaction with other components.

Next, aliil, which is rendered deaf by the present invention! As for the chiral nematic liquid crystal among the components of the product, it is possible to prevent reverse tilt by adding a small amount of wrinkle component to the panel for displaying tay attenuation, and to improve the contrast by using it for dust host display. - ni sho, l' is the wrinkle component added liquid crystal 1
Many examples of the use of this component are known. Maenaka K uses the ability of chiral nematic liquid crystals to return to the helical spiral structure to increase the response speed, which is well known in the present invention.
The addition of chiral nematic liquid crystal has the above-mentioned effect, that is, the effect of improving response speed, even in the two-wave driving method. In the two-frequency driving method, when driving by a black-and-white wave having a higher frequency than fc, that is, when aligning liquid crystal molecules in a seven-square pattern, there is an effect of increasing the speed by %.

The present inventors have determined that by introducing the above-mentioned components in appropriate proportions, the absolute value of Δa & Δl is c%.In the conventional composition, increasing the absolute value of Δtm takes into consideration the balance with the properties of the intermediate. However, by adding chiral nematic liquid crystals, we were able to dramatically increase the response speed for various applications and voltages. - A composition that is caused by the 0-shot 1j14, which is predicted to have a considerable influence on the interaction between different components, viscosity, and the response. Even if KsP-, this interaction is
It seems to be working in the direction of the 049 sexual reform, but I look forward to the 912) research that will provide a physical or quantum mechanical explanation on this point.

The above is due to the use of the components according to the present invention in order to extract 411-1.

2.11 Voltage margin is wide.

First, regarding the margin, the dielectric anisotropy of liquid crystal 4rs1m dependence chart 4FKJ, ΔεL
is the dielectric anisotropy at a low driving frequency, and Δ8 is the dielectric anisotropy at the Takaoka wave O driving frequency. As you can see, Δl decreases rapidly as the species increases. Although there are some differences in this tendency depending on the liquid crystal, it is the basic 1fIII of the liquid crystal, so 11111 is 4! If the pigeonhouse to be used is selected in a speciation region with a small amount of t change of Δε, then the carp will be in a certain S* high temperature region. The cost is to lower the viscosity of the liquid crystal and use it. Based on the fact that it is undeniable that Δ8 iris works full-time to some extent when converting to K11f expenses, we also take a wide -1I' margin.
Fi, it is necessary to adopt an am that has good transparency of the liquid crystal, which means that the response is reached under a constant voltage and the light transmittance - line is high. In this case, it is a prerequisite that the above-mentioned characteristic 1 is satisfied. Regarding the voltage margin, "ゝ" can be considered in the same way.

5. Diagnosis should be performed while ensuring high II reliability.

Many studies and experiments have been conducted on the chemical, optical, and electrochemical stability of liquid crystals.

Since all the liquid crystals produced by the Zero-Hatsu 94 are ester-based liquid crystals, the optical reliability is high.
Ru.

The above-mentioned Kujo characteristics 1, 2. With the aim of producing S in a well-balanced manner and at a performance level, the present invention aims to create a monocrystalline material with excellent strength as a small material by appropriately selecting the blending ratio of each of the above-mentioned components. Kade-e, that is, l! This is a composition as shown in IK.

[In the upper t's, p, R' are vertical cords 1 to 1.
Table 1 Next, the details of the present invention will be explained with reference to Examples.

The liquid crystal listed in Example 112 was prepared, and its basic characteristics and light transmittance were 4I@! - Pee.

C size, lI medium needle 0slist shows the frequency dependence of the cod electric rate of the liquid crystal composition shown in 111E711KII2, provided that the constant 11 degrees is sO°C.

This liquid crystal panel was sealed in a test cell with a casing thickness of 5JllK, and a low-oka liquid signal 4 (50V, 1][11g) and a high frequency signal (
sov.

1! SOKi1g) was used to drive the imager one ivy, and it showed the light transmission characteristics that @swg rewards. ail
xy, h dyna svr drive, repeat cycle is 268
% Opening time α6 to α7■-6 allows for a return response. However, the rubbing angle of the cell used at time t is 7. ,
,,oj, the direction of light of the polarizing plates sandwiching the cells were at right angles to each other, and the Il constant temperature was 40°C.

Next, perform a printing experiment using liquid crystal light pulp.
The driving force is also 111gm, and the structural formula is 01.
Ml A410: Use a high-intensity fluorescent lamp with a phosphor and a 98-cm sensitized photoreceptor with Qi.

As shown in Section 11, the defective parts were examined twice, and the change in the speed of movement of the photosensitive drum was 5□age. The main point of driving the liquid crystal light pulp and reading the memorandum is that 0N-0.
Corresponding to 1Pν, it is possible to form a clear association with 190
Is this example a book? An example of the use of the liquid crystal light pulp provided by
It can also be applied to the front display cape.

Furthermore, the liquid crystal compound used in this example is just an example, and even if each component is changed to the group of its components, it is also possible to
The present inventor has conducted experiments to find that the same characteristics as in this example can be obtained even when the honey tip is within the range of the O-in O-combination ratio that is set in the range of Kosabakyo. For some reason, the original & JI
IFi is not defined in this embodiment.

As stated above, the present invention utilizes dielectric dispersion of liquid crystal,
In order to improve the responsiveness of the liquid crystal material in MA light pulp, which is produced using a two-frequency drive and a high-speed switching tube, Kit! As a result, even when used for ν, it was possible to dramatically improve the writing speed of the printing die by 11 degrees and the voltage margin, so the effects of the present invention are greatly appreciated.

[Brief explanation of drawings]

The first picture 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. No. 311 is the upper part 1111 of the liquid crystal panel used for liquid crystal light pulp. The 411th is the signal applied to the liquid crystal light pulp and the O light response characteristics at that time. @S■ is proportional to the frequency # of the dielectric constant of the liquid crystal. The 6th WJ is the electroanisotropy characteristic of liquid crystal OII. Number 711 is the frequency 41 property of the dielectric constant of the liquid crystal shrinkage material used in this example. 8th Il is the photoresponse characteristic of the liquid crystal light pulp according to this example. Applicant: Hoseikosha System Co., Ltd. Patent Attorney 1#Sat v-18 No. 111 4) 2nd [] 13 figures. Figure 4 Figure 5 □ Sunny Fi1 (+mHc) Figure 8

Claims (1)

[Claims] Two glass panes having NESA electrodes inside are placed facing each other, and a liquid crystal panel with an Ell crystal material sandwiched between them has a high frequency component below the cross frequency c (abbreviated as fe) of the liquid crystal material. No. 1 a with f′z*t″ frequency component 114
When applied alone or in a superimposed manner, the liquid crystal light 11"1lilltK is applied to control the strong change in transmitted light.
A liquid crystal side proboscis characterized in that the liquid crystal material has a structure as shown below. (R,n'Fi vertical atoms 1-1~ in the top i!decay table
Represents a straight chain alcohol having 8 atoms]