JPS6295380A - Chiral smectic liquid crystal composition - Google Patents

Abstract

PURPOSE:The title composition that contains a chiral smectic liquid crystal compound of negative dielectric anisotropy, thus manifesting satisfactory memorizing properties even in 2 micrometer-measuring cells, and being used in high multiplex liquid crystal display. CONSTITUTION:The objective composition contains at least one of chiral smectic or smectic liquid crystal with negative dielectric anisotropy. Further, it is preferred that the composition additionally contains chiral smectic or smectic liquid crystal with positive dielectric anisotropy.

Description

[Detailed description of the invention] (Application field) The present invention relates to chiral smectic liquid crystal compositions.

More specifically, the present invention relates to a ferroelectric liquid crystal composition that exhibits good memory properties by containing chiral smectic or smectic compounds having negative dielectric anisotropy.

(Prior Art) In recent years, liquid crystal displays have come to be widely used as display devices due to their characteristics such as thinness, light weight, and low power consumption. However, most of these display devices are T-N type display devices using nematic crystals.
In application fields that require high multiplexing, response is still slow and improvements are needed.

Under these circumstances, attention has been drawn to the fact that sufficient contrast cannot be obtained when displaying chiral smectic liquid crystals having optically active sites.

(Objective of the Invention) Therefore, an object of the present invention is to provide a chiral smectic liquid crystal composition that exhibits sufficient memory properties even in cells of about 2 μm.

(Means of the Invention) Based on the above object, the present invention provides a chiral smectic liquid crystal composition that satisfies the above conditions, and contains at least one component of chiral smectic or smectic liquid crystal compound having negative dielectric anisotropy. The above object is achieved by a liquid crystal composition characterized by the following.

(Embodiments of the Invention) Example 1 An electro-optical element, which was encapsulated in two substrates having transparent electrodes whose surfaces had been subjected to rubbing treatment and assembled so that the cell thickness was 2 μm, was placed between two substrates perpendicular to each other. When it was held between polarizing plates and an AC electric field of ±15V was applied, it responded depending on the direction of the electric field. At this time, m/m p = a8, which is improved compared to m/p = CL6 when using only pace liquid crystal A,
The contrast was also good at 1:5.

Example Z A negative chiral smectic liquid crystal 0.2H, O-◎-coo-◎-OH: C
,-Co.

Omu J An electro-optical element assembled to have a thickness of 2 μm was sandwiched between two mutually orthogonal polarizing plates, and when a full alternating current electric field of ±15 V was applied, it responded depending on the direction of the electric field. At this time, m/p = Q, 9, which is improved compared to m/p = 06 when using only pace LCD A, and the contrast is also 1:1.
0-i was good.

Example & Liquid crystal B, negative chiral smectic α crystal self, H2,O-<chicoo-<>
an= c-coocH, aged He, H, the present invention ON OH, mixed at 20%.

The liquid crystal composition of Example 1 and 2 was sealed in the glass-based cell shown in Examples 1 and 2, and the electro-optical element assembled so as to have a cell thickness of 2 μm was sandwiched between two polarizing plates orthogonal to each other, and ±1
When a 5 V photocurrent electric field was applied, the response depended on the direction of the electric field. At this time, In/engine p=α8, and pace liquid crystal B
It was improved compared to the case of only CL5, where M/P = CL5, and the contrast was also good at 1:10 or more.

(Effects of the Invention) As described above, the ferroelectric liquid crystal composition of the present invention can be used in Examples 1 to 2.
6, if g′vt anisotropy is negative, El
Whether or not it exhibits the m''C phase, by mixing these, it is possible to obtain a chiral smectic liquid crystal composition that exhibits good memorabilia and high cosf in cells of about 2 μm.

Applications of the invention include high speed liquid crystal shutters and high multiplex liquid crystal displays.

[Brief explanation of drawings]

Figure 1 shows the electric field applied to the liquid crystal and the optical response of the liquid crystal. +11 shows the ground level, and (2) shows the optical response waveform of the liquid crystal.
(21a d engineering m level k, (21-b iri engineering p
Level f s (31 indicates the applied voltage waveform.

Claims (1)

[Scope of Claims] 1) A cameral smectic liquid crystal composition containing at least one component of chiral smectic or smectic liquid crystal compound having negative dielectric anisotropy. 2) It is characterized by containing at least one component each of chiral smectic or smectic liquid crystal compound having positive dielectric anisotropy and chiral smectic or smectic liquid crystal compound having negative dielectric anisotropy. Chiral smectic liquid crystal composition.