JPH06230392A - Orientation control film for ferroelectric liquid crystal and ferroelectric liquid crystal element formed by using the same - Google Patents

Abstract

PURPOSE:To provide the orientation control film for a ferroelectric liquid crystal which has the excellent orientability and bistability of the ferroelectric liquid crystal and is suitable for increasing a contrast and the ferroelectric liquid crystal element constituted by using the film. CONSTITUTION:This orientation control film for the ferroelectric liquid crystal is constituted by using a high polymer contg. the skeleton expressed by the formula in its molecular long chain and the ferroelectric liquid crystal element is constituted by using this control film. In the formula, R1 denotes a 4 to 22C alkyl group; R2 denotes hydrogen or a 1 to 22C alkyl group, respectively' R3 to R10 denote hydrogen or 1 to 4C alkyl groups which are the same as or different from each other.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an alignment control film for a ferroelectric liquid crystal capable of improving display characteristics by improving the initial alignment state of ferroelectric liquid crystal molecules, and a ferroelectric film using the same. Liquid crystal device.

[0002]

2. Description of the Related Art In a conventional liquid crystal display device, a twisted nematic structure (hereinafter, referred to as T) having a structure in which an arrangement direction of nematic liquid crystal molecules is twisted by 90 degrees between a pair of upper and lower electrode substrates.
Abbreviated as N. ) Elements and super twisted nematic (hereinafter abbreviated as STN) elements twisted by 180 to 300 degrees are mainly used. These devices utilize the dielectric anisotropy of liquid crystal molecules, and apply a voltage to the liquid crystal to move the liquid crystal to turn it on. However, the TN element has a drawback that the driving margin becomes narrower and the contrast is deteriorated as the driving method becomes multiplex, and the STN element has a drawback that the response speed becomes slower when used for a large capacity display. There is.

In order to overcome such drawbacks, a new device using a ferroelectric liquid crystal has been proposed by Clark and Lagerwall. (JP-A-56-10726
This device is turned on and off by reversing the polarity of the electric field and reversing the spontaneous polarization of the ferroelectric liquid crystal.
Compared with the TN element and the STN element, the memory property, the high-speed response property, the high duty driving property, and the high density and high image quality are extremely excellent.

In order to make full use of such a function of the ferroelectric liquid crystal, it is necessary to create a special alignment state suitable for the ferroelectric liquid crystal. That is, in order to obtain a ferroelectric liquid crystal element, a special alignment film that controls the alignment of the ferroelectric liquid crystal is required. However, the alignment film that has been conventionally used is an alignment film for nematic liquid crystal, and an alignment control film that has been subjected to a uniaxial alignment process such as a rubbing process or an oblique vapor deposition process has been mainly used.

[0005]

However, when such a conventional alignment control film is applied to a ferroelectric liquid crystal device, it has the following problems. One of the drawbacks is that ferroelectric liquid crystals have a lower molecular symmetry than nematic liquid crystals, making it difficult to align them uniformly, which makes it difficult to obtain uniformly aligned devices. Is mentioned. According to Clarke and Lagabal, the tilt angle of a ferroelectric liquid crystal that realizes bistability should be the same as the tilt angle Θ that is 1/2 the cone angle as shown in FIG. 2, the tilt angle θ of the ferroelectric liquid crystal becomes smaller than the tilt angle θ by several degrees. As a result, the transmittance is reduced to about 30 to 50%.

In order to set the tilt angle θ of the ferroelectric liquid crystal to the maximum tilt angle Θ, the alignment of the liquid crystal molecules needs to be in the uniform alignment state shown in FIG. 3a, but actually, as shown in FIG. 3b. There is a problem that a sufficiently large tilt angle θ cannot be formed because each of the liquid crystal molecules adjacent to is twisted and aligned at a twist angle α. The liquid crystal element under such a twist alignment state has lower contrast than the uniform alignment, and exhibits optical response to a pulse signal as shown in FIGS. 4 and 5, and this optical response is obtained when performing multiplexing driving. May cause the display screen to flicker. Therefore, in order to obtain a high-contrast and flicker-free screen, it is necessary to perform uniform orientation.

Recently, it has been found that the ferroelectric liquid crystal has two alignment states. All of them are chiral smectic C (hereinafter, S
Abbreviated as mC ^* . ) Due to the structure of the phase. It was found that the phase structure of SmC ^* is different from the initially thought book-shelf type shown in FIG. 3 and actually has a structure in which it is bent into a “<” shape as shown in FIG. (TPRieke
r, NAClark et al., Phys Rev. Lett., 59 , (1987) 265
8). Therefore, when an alignment control film having a pretilt angle is used, the ferroelectric liquid crystal is
It rises by a certain value θ _{P in the} rubbing direction. The orientation state is slightly different depending on which direction the "C" character faces the rubbing direction. Kambe et al. Have arranged these two states in such a way that the “K” character is arranged in the forward direction (→) with respect to the rubbing direction (→), and C1 is arranged with respect to the rubbing direction (→). "
The letter C is arranged in the opposite direction (←) and is defined as C2. (J.Kanbe, et al., Ferroelectrics, 114 ,
(1991) 3). It is said that which of C1 and C2 is more likely to appear is related to the pretilt angle.
According to Kamibe et al., In the C1 state, the liquid crystal molecules existing at the interface of the orientation control film are θ + δ> θ _P (where θ is the tilt angle, δ
Represents the layer tilt angle, and θ _p represents the pretilt angle. ) Exists, and conversely, the C2 state exists in the state of θ−δ> θ _P. The high orientation control films pretilt angle, the conditions of θ + δ> θ _P is satisfactory, θ-δ> θ _P
Is not satisfied, it is believed that C1 orientation can be obtained.

Similarly, for uniform orientation, C1U, C2
There are two orientation states of U. A schematic diagram of these director profiles is shown in FIG. In the C1U orientation, the value of θ slightly decreases in the central part of the cell, but takes a value close to Θ. On the other hand, the C2U orientation slightly increases in the central portion of the cell, but the value of θ becomes smaller than the C1U orientation. From this, it is considered that the C1U orientation has a higher contrast between the bright state and the dark state than the C2U orientation. On the other hand, since the C2U orientation appears in a lower temperature region than the C1U orientation, the energy is low and it may be more stable against external impact or strain than the C1 orientation.

The method considered to be the best method for obtaining a ferroelectric liquid crystal element exhibiting uniform orientation is as follows.
The use of an orientation control film in which SiO or the like is obliquely vapor-deposited is used, but in order to industrially produce such an orientation control film, the scale of the apparatus becomes large and the restrictions on the apparatus also increase. Therefore, it is desired to replace such an alignment control film with an alignment control film using an organic thin film such as a nematic liquid crystal element.

The object of the present invention is to solve the above-mentioned problem, namely to increase the tilt angle in a non-helical ferroelectric liquid crystal which realizes at least two stable states, in particular bistability, and thereby to improve the pixel (EN) Provided are an alignment control film capable of improving the transmittance at the time of opening a shutter and increasing uniform alignment (especially C1U), which is easy to form a thin film, and a ferroelectric liquid crystal device using the alignment control film. Another object of the present invention is to provide a ferroelectric liquid crystal element that does not cause flicker on the screen.

[0011]

The present invention is an alignment control film for a ferroelectric liquid crystal characterized by using a specific polyimide for the alignment control film in the alignment control of a ferroelectric liquid crystal. In a liquid crystal device having a substrate and a ferroelectric liquid crystal having an array of molecules forming a plurality of layers perpendicular to the planes of the pair of parallel substrates, at least one of the pair of parallel substrates is provided. A ferroelectric liquid crystal device characterized in that a substrate has an alignment control film for preferentially aligning the plurality of layers in one direction, and the alignment control film is composed of a specific polyimide.

The present invention will be described in more detail below. The alignment control film for a ferroelectric liquid crystal and the ferroelectric liquid crystal device using the same according to the present invention have the following general formula:

[0013]

[Chemical 3]

An alignment control film for a ferroelectric liquid crystal, which comprises a polymer having a skeleton represented by the following as a main chain. (2) General formula

[0015]

[Chemical 4]

An alignment control film for a ferroelectric liquid crystal, which comprises a polyimide polymer substance having 5 to 100 mol% of a repeating unit represented by: (3) A ferroelectric liquid crystal device using the alignment control film for ferroelectric liquid crystal of (1) or (2). (4) The ferroelectric liquid crystal device according to (3), wherein the ferroelectric liquid crystal device is a liquid crystal light modulation device. (5) The ferroelectric liquid crystal device according to (3), wherein the ferroelectric liquid crystal device is a liquid crystal display device. Is.

Specific examples of the diamino compound used as a raw material of the alignment control film for a ferroelectric liquid crystal of the present invention are: 1,1-bis [4- (4-aminophenoxy) phenyl] pentane 1,1-bis [ 4- (4-aminophenoxy) phenyl] hexane 1,1-bis [4- (4-aminophenoxy) phenyl] heptane 1,1-bis [4- (4-aminophenoxy) phenyl] octane 1,1-bis [4- (4-Aminophenoxy) phenyl] nonane 1,1-bis [4- (4-aminophenoxy) phenyl] decane 1,1-bis [4- (4-aminophenoxy) phenyl] undecane 1,1- Bis [4- (4-aminophenoxy) phenyl] dodecane 1,1-bis [4- (4-aminophenoxy) phenyl] tridecane 1,1-bis [4- (4-a Minophenoxy) phenyl] tetradecane 1,1-bis [4- (4-aminophenoxy) phenyl] pentadecane 1,1-bis [4- (4-aminophenoxy) phenyl] hexadecane 1,1-bis [4- (4 -Aminophenoxy) phenyl] heptadecane 1,1-bis [4- (4-aminophenoxy) phenyl] octadecane 1,1-bis [4- (4-aminophenoxy) phenyl] nonadecane 1,1-bis [4- ( 4-Aminophenoxy) phenyl] eicosane 1,1-bis [4- (4-aminophenoxy) phenyl] heneicosane 1,1-bis [4- (4-aminophenoxy) phenyl] docosane 1,1-bis [4- (4-Aminophenoxy) phenyl] tricosane

2,2-bis [4- (4-aminophenoxy) phenyl] hexane 2,2-bis [4- (4-aminophenoxy) phenyl] heptane 2,2-bis [4- (4-aminophenoxy) ) Phenyl] octane 2,2-bis [4- (4-aminophenoxy) phenyl] nonane 2,2-bis [4- (4-aminophenoxy) phenyl] decane 2,2-bis [4- (4-amino) Phenoxy) phenyl] undecane 2,2-bis [4- (4-aminophenoxy) phenyl] dodecane 2,2-bis [4- (4-aminophenoxy) phenyl] tridecane 2,2-bis [4- (4- Aminophenoxy) phenyl] tetradecane 2,2-bis [4- (4-aminophenoxy) phenyl] pentadecane 2,2-bis [4- (4-aminophenoxy) ) Phenyl] hexadecane 2,2-bis [4- (4-aminophenoxy) phenyl] heptadecane 2,2-bis [4- (4-aminophenoxy) phenyl] octadecane 2,2-bis [4- (4-amino) Phenoxy) phenyl] nonadecane 2,2-bis [4- (4-aminophenoxy) phenyl] eicosane 2,2-bis [4- (4-aminophenoxy) phenyl] heneicosane 2,2-bis [4- (4- Aminophenoxy) phenyl] docosane 2,2-bis [4- (4-aminophenoxy) phenyl] tricosane 2,2-bis [4- (4-aminophenoxy) phenyl] tetracosane

1,1-bis [4- (4-aminophenoxy) -3,5-dimethylphenyl] pentane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] hexane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] heptane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] octane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] nonane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] decane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] undecane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] dodecane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] tridecane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] tetradecane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] pentadecane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] hexadecane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] heptadecane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] octadecane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] nonadecane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] eicosane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] heneicosane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] docosane 1,1-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] tricosane

2,2-bis [4- (4-aminophenoxy) -3,5-dimethylphenyl] hexane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] heptane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] octane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] nonane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] decane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] undecane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] dodecane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] tridecane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] tetradecane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] pentadecane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] hexadecane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] heptadecane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] octadecane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] nonadecane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] eicosane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] heneicosane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] docosane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] tricosane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] tetracosane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] pentacosane 2,2-bis [4- (4-aminophenoxy) -3,5
-Dimethylphenyl] hexacosane

1,1-bis [4- (4-amino-3,5
-Dimethylphenoxy) phenyl] pentane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] hexane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) Phenyl] heptane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] octane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] nonane 1 , 1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] decane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] undecane 1,1-bis [4- (4-Amino-3,5-dimethylphenoxy) phenyl] dodecane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] tride 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] tetradecane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] pentadecane 1,1 -Bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] hexadecane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] heptadecane 1,1-bis [4 -(4-Amino-3,5-dimethylphenoxy) phenyl] octadecane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] nonadecane 1,1-bis [4- (4- Amino-3,5-dimethylphenoxy) phenyl] eicosane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] heneicosane 1, 1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] docosane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] tricosane

2,2-bis [4- (4-amino-3,5
-Dimethylphenoxy) phenyl] hexane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] heptane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) Phenyl] octane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] nonane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] decane 2 , 2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] undecane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] dodecane 2,2-bis [4- (4-Amino-3,5-dimethylphenoxy) phenyl] tridecane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] teto Decane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] pentadecane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] hexadecane 2,2 -Bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] heptadecane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] octadecane 2,2-bis [4 -(4-Amino-3,5-dimethylphenoxy) phenyl] nonadecane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] eicosane 2,2-bis [4- (4- Amino-3,5-dimethylphenoxy) phenyl] heneicosane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] docosane 2, 2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] tricosane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) phenyl] tetracosane

1,1-bis [4- (4-amino-3,5
-Dimethylphenoxy) -3,5-dimethylphenyl]
Pentane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] hexane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-Dimethylphenyl] heptane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] octane 1,1-bis [4- (4-amino) -3,5-Dimethylphenoxy) -3,5-dimethylphenyl] nonane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] decane 1,1- Bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] undecane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5- Dimethyl Phenyl] dodecane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] tridecane 1,1-bis [4- (4-amino-3,5-dimethyl) Phenoxy) -3,5-dimethylphenyl] tetradecane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] pentadecane 1,1-bis [4- (4 -Amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] hexadecane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] heptadecane 1, 1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] octadecane 1,1-bis [4- (4-amino-3,5-dimethyl) Phenoxy) -3,5-dimethylphenyl] nonadecane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] eicosane 1,1-bis [4- (4 -Amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] heneicosane 1,1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] docosane 1, 1-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] tricosane

2,2-bis [4- (4-amino-3,5)
-Dimethylphenoxy) -3,5-dimethylphenyl]
Hexane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] heptane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] octane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] nonane 2,2-bis [4- (4-amino) -3,5-Dimethylphenoxy) -3,5-dimethylphenyl] decane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] undecane 2,2- Bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] dodecane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5- Dimethyl Phenyl] tridecane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] tetradecane 2,2-bis [4- (4-amino-3,5-dimethyl) Phenoxy) -3,5-dimethylphenyl] pentadecane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] hexadecane 2,2-bis [4- (4 -Amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] heptadecane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] octadecane 2, 2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] nonadecane 2,2-bis [4- (4-amino-3,5-dimethyl) Ruphenoxy) -3,5-dimethylphenyl] eicosane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] heneicosane 2,2-bis [4- ( 4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] docosane 2,2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] tricosane 2 , 2-bis [4- (4-amino-3,5-dimethylphenoxy) -3,5-dimethylphenyl] tetracosane, and the like.

The tetracarboxylic dianhydride used as a raw material for the alignment control film for a ferroelectric liquid crystal of the present invention is an aromatic type,
Either an aliphatic system or a complex system having both aromaticity and aliphaticity may be used. Although not particularly limited, specific examples include pyromellitic dianhydride,
Biphenyl tetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, bis (dicarboxyphenyl) ether dianhydride, bis (dicarboxyphenyl) sulfone dianhydride, bis (dicarboxy Diphenyl) methane dianhydride,
Cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexanetetracarboxylic dianhydride, dicyclohexanetetracarboxylic dianhydride, dicyclopentanetetracarboxylic dianhydride, bis (dicarboxycyclohexyl) Ether dianhydride, bisdicarboxycyclohexyl sulfone dianhydride, bis (dicarboxycyclohexyl) methane dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-
Methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 1,
3,3a, 4,5,9, b-hexahydro-5- (tetrahydro-2,5, dioxo-3-furanyl) -naphtho [1,2-c] furan 1,3-dione and the like can be mentioned. .

To improve the adhesion of the ferroelectric liquid crystal alignment control film of the present invention to the substrate, an aminosilicon compound or a diaminosilicon compound can be introduced. Specific examples of the liquid crystal alignment film containing the silicon compound include those represented by the general formula:

[0027]

[Chemical 5]

And / or the general formula

[0029]

[Chemical 6]

The structural unit represented by the formula (wherein, in the general formulas 〓 and 〓, X is an alkylene group or phenylene group having 1 to 3 carbon atoms, Y is an alkyl group having 1 to 6 carbon atoms, and R is a tetravalent aromatic group. Group, an aliphatic group, or a composite group having both tetravalent aromaticity and aliphaticity, m represents an integer of 0 to 4), and is 0.1 to 50 mol%, preferably 0.1 to A liquid crystal alignment film containing 20 mol% is mentioned. The following compounds may be mentioned as specific examples of the aminosilicon compound to be introduced. First, as an aminosilicon compound for producing the structural unit represented by the general formula (〓),

[0031]

[Chemical 7]

And the like. When introducing these aminosilicon compounds, the above general formula (〓)
50 mol% or less, preferably 20 mol% or less, of the diamino compound represented by can be used by replacing it with an aminosilicon compound. Further, as the diaminosilicon compound for producing the structural unit represented by the general formula (〓),

[0033]

[Chemical 8]

And the like. When introducing these diaminosilicon compounds, the above general formula (〓)
50 mol% or less, preferably 20 mol% or less, of the diamino compound represented by can be used by replacing it with an aminosilicon compound.

The polyimide polymer used as the alignment control film for the ferroelectric liquid crystal of the present invention is, in addition to the above-mentioned components, an aromatic diamino compound, an alicyclic diamino compound, a diamino having both aromaticity and aliphaticity. It is also possible to introduce and organize the compound and its derivatives.

In order to provide the alignment control film for a ferroelectric liquid crystal of the present invention on a substrate, a polyimide compound is generally insoluble in a solvent, so that the precursor tetracarboxylic dianhydride is condensed with a diamino compound. The polyamic acid obtained by the above is dissolved in a solvent and coated on a substrate. Specifically, polyamic acid is converted into N-methyl-2-pyrrolidone (N
MP), dimethylacetamide (DMAc), dimethylformamide (DMF), dimethylsulfoxide (DM)
SO), butyl cellosolve, ethyl carbitol and the like to prepare a 0.1 to 30 wt% solution, preferably 1 to 10 wt% solution.
Coating is performed by dipping, spin coating, spraying, printing or the like to form a coating film on the substrate. After coating, 50-150
After evaporating the solvent at C, preferably 80-120 C,
150 ° C to 400 ° C, preferably 180 ° C to 280 ° C
And heat treatment is performed to cause dehydration ring closure reaction to provide a liquid crystal alignment film made of a polyetherimide polymer film. if,
When the adhesion of the obtained polymer film to the substrate is not good, this can be improved by forming the polymer film after the surface treatment of the substrate surface with the silane coupling material in advance. Thereafter, the coated surface is rubbed with a cloth or the like to a constant fragrance to obtain an alignment control film for liquid crystal.

An electrode, specifically, a transparent electrode such as ITO (indium oxide-tin oxide) is formed on this substrate. Further, an insulating film for the purpose of preventing elution of alkali from the substrate, an undersheet film such as a polarizing plate or a color filter may be formed under the electrode, and an insulating film or a color filter may be formed on the electrode. An overcoat film such as a film or a light transmission preventing film may be formed. The constitution of the conventional liquid crystal element can be applied to these electrodes, undercoat, overcoat and other constituent elements in the cell.

A cell is formed using such a substrate, liquid crystal is injected, and then the injection port is sealed. Alternatively, the liquid crystal may be sprinkled on the substrate, and then the substrates may be stacked and sealed so that the liquid crystal does not leak. As the injected liquid crystal, various liquid crystals such as a normal ferroelectric liquid crystal and a liquid crystal added with a dichroic dye can be used.

The ferroelectric liquid crystal used in the ferroelectric liquid crystal device of the present invention is a liquid crystal which has spontaneous polarization P _s and which can be inverted to −P _s by an externally applied electric field and has a chiral smectic C phase. I have.

Use of the alignment control film for a ferroelectric liquid crystal of the present invention acts to increase uniform alignment having a large contrast. In particular, it is particularly useful to produce an orientation control film with a polyetherimide polymer having a carbon chain length of 5 to 15 as the main component, since the C1U orientation with high contrast increases. It is considered that this is because the introduction of side chains increases the pretilt angle and stabilizes the doglegged structure.

[0041]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 Using N-methyl-2-pyrrolidone (MNP) as a solvent, pyromellitic anhydride and 2,2-bis [4]
-(4-Aminophenoxy) phenyl] octane and para-aminophenyltrimethoxysilane were reacted at a ratio of 8: 7: 1.8 to obtain a polyamic acid solution. When this solution was diluted to 3% by weight with a 1: 1 mixed solution of NMP and butyl cellosolve, the viscosity was 9.3 Cp. The polyamic acid thus obtained was applied by spin coating (spinner method) onto a transparent glass substrate having an ITO electrode on one side. The rotation conditions were 3000 rpm and 15 seconds. After the coating film was dried at 100 ° C. for 10 minutes, the temperature was raised in an oven for 40 minutes and heat treatment was performed at 200 ° C. for 90 minutes to obtain a polyetherimide having a film thickness of about 600A. The base on which this polyetherimide film is formed
Rubbing was performed with a push-in amount of 0.4 mm using a 1.8 mm rayon cloth to prepare a ferroelectric liquid crystal cell with a cell thickness of 2 microns in which the rubbing directions were parallel and both substrates were oriented in the same direction. After heating this liquid crystal cell at 110 ℃, inject the ferroelectric liquid crystal "CS-1031" of chisso, and from 100 ℃ to 70
Orientation was carried out by slowly cooling to room temperature at a rate of 1 ° C./minute and then to room temperature. When the initial orientation of this cell was observed under crossed Nicols, uniform orientation was obtained in a range of 90%. The breakdown was 70% for C1U and 20% for C2U. Incidentally, after rubbing the substrate on which this polyetherimide film was formed, cells having a cell thickness of 20 microns were prepared by rubbing directions in parallel and in mutually different directions, and a liquid crystal composition ZLI-1132 manufactured by Merck was injected, After being subjected to isotropic treatment at 120 ° C. for 30 minutes, it was gradually cooled and aligned. When this pretilt angle was measured by the crystal rotation method, it was 7.5 degrees.

Example 2 Using N-methyl-2-pyrrolidone (MNP) as a solvent, pyromellitic anhydride and 2,
2-bis [4- (4-aminophenoxy) phenyl] decane and para-aminophenyltrimethoxysilane 8:
The reaction was performed at a ratio of 7: 1.8 to obtain a polyamic acid solution. When this solution was diluted to 3% by weight with a 1: 1 mixed solution of NMP and butyl cellosolve, the viscosity was 7.3 Cp.
Became. The polyamic acid thus obtained was applied by spin coating (spinner method) onto a transparent glass substrate having an ITO electrode on one side. Rotation condition is 3000 rpm, 1
It was 5 seconds. After coating, after drying at 100 ° C for 10 minutes, the temperature was raised in an oven for 40 minutes, and the temperature was raised to 9 ° C at 200 ° C.
A heat treatment was performed for 0 minutes to obtain a polyetherimide having a film thickness of about 600A. The substrate on which this polyetherimide film is formed is pushed in using a rayon cloth with 1.8 mm wool and a pushing amount of 0.4 mm.
Then, a ferroelectric liquid crystal cell having a cell thickness of 2 microns in which the rubbing directions were parallel and both substrates were oriented in the same direction was prepared. After heating this liquid crystal cell at 110 ° C, inject the ferroelectric liquid crystal "CS-1031" of the chisso type at 100 ° C.
To 70 ° C. at a rate of 1 ° C./min, and then gradually cooled to room temperature for orientation. When the initial orientation of this cell was observed under crossed Nicols, uniform orientation was obtained in a range of 90%. The breakdown was 80% for C1U and 10% for C2U. still,
After rubbing the substrate on which the polyetherimide film was formed, cells having a cell thickness of 20 microns were prepared by rubbing directions in parallel and in mutually different directions, and a liquid crystal composition ZLI-1132 manufactured by Merck & Co., Inc. was injected at 120 ° C. After being subjected to isotropic treatment for 30 minutes, it was gradually cooled and oriented. When this pretilt angle was measured by the crystal rotation method, it was 8.4 degrees.

Example 3 Using N-methyl-2-pyrrolidone (MNP) as a solvent, pyromellitic anhydride and 2,
2-bis [4- (4-aminophenoxy) phenyl] tridecane and paraaminophenyltrimethoxysilane were reacted at a ratio of 8: 7: 1.8 to obtain a polyamic acid solution. This solution was mixed with NMP and butyl cellosolve 1: 1.
When diluted to 3% by weight with the mixed solution of, the viscosity was 14.
It became 9 Cp. The polyamic acid thus obtained was applied by spin coating (spinner method) onto a transparent glass substrate having an ITO electrode on one side. Rotation condition is 4000rp
m was 15 seconds. After coating, dry at 100 ° C for 10 minutes and then raise the temperature in the oven for 40 minutes to 200
A heat treatment was performed at 90 ° C. for 90 minutes to obtain a polyetherimide having a film thickness of about 600A. Push the substrate on which this polyetherimide film is formed using a rayon cloth with 1.8mm wool.
Rubbing was performed at 0.4 mm to prepare a ferroelectric liquid crystal cell having a cell thickness of 2 μm in which the rubbing directions were parallel and both substrates were oriented in the same direction. After heating this liquid crystal cell at 110 ℃, inject the ferroelectric liquid crystal "CS-1031" of the chisso.
Orientation was performed by gradually cooling from 100 ° C. to 70 ° C. at a rate of 1 ° C./minute and then to room temperature. When the initial orientation of this cell was observed under crossed Nicols, uniform orientation was obtained in a range of 70%. The breakdown was C1U 70%, and no C2U orientation was observed. Incidentally, after rubbing the substrate on which this polyetherimide film was formed, cells having a cell thickness of 20 microns were prepared by rubbing directions in parallel and in mutually different directions, and a liquid crystal composition ZLI-1132 manufactured by Merck was injected, After being subjected to isotropic treatment at 120 ° C. for 30 minutes, it was gradually cooled and aligned. When this pretilt angle was measured by the crystal rotation method, it was 9.2 degrees.

(Comparative Example 1) Polyvinyl alcohol (PV
A) A 0.3% aqueous solution was applied by a spin coating method (spinner method) onto a transparent glass substrate having an ITO electrode on one surface.
The rotation conditions were 3000 rpm and 15 seconds. After coating, 150
It was dried at 30 ° C. for 30 minutes to obtain a PVA film having a film thickness of about 50A. The PVA film-formed substrate was rubbed with a 1.8 mm thick rayon cloth at a push-in amount of 0.4 mm, and the rubbing directions were parallel and both substrates were oriented in the same direction. Ferroelectric liquid crystal with a cell thickness of 2 microns. Created a cell. After warming this liquid crystal cell at 110 ℃, ferroelectric liquid crystal "CS-1031" made by Chisso was injected and the temperature was raised from 100 ℃ to 70 ℃ at 1 ℃ /
Orientation was then achieved by slow cooling to room temperature at a rate of minutes. Observing under the initial orientation orthogonal row Nicol of this cell,
The entire surface was twisted. After rubbing the substrate on which the PVA film was formed, cells having a cell thickness of 20 microns were prepared by rubbing directions parallel to each other and in different directions, and a liquid crystal composition ZLI-1132 manufactured by Merck & Co., Inc. was injected at 120 ° C. After being subjected to isotropic treatment for 30 minutes, it was gradually cooled and oriented. When this pretilt angle was measured by the crystal rotation method, it was approximately 0 degree.

Comparative Example 2 Using N-methyl-2-pyrrolidone (MNP) as a solvent, pyromellitic dianhydride, bis (4-aminophenyl) ether and para-aminophenyltrimethoxysilane were mixed at 8: 7: 1. The reaction was carried out at a ratio of 8 to obtain a polyamic acid solution. When this solution was diluted to 3% by weight with a 1: 1 mixed solution of NMP and butyl cellosolve, the viscosity was 17.3 Cp. The polyamic acid thus obtained was applied by spin coating (spinner method) onto a transparent glass substrate having an ITO electrode on one side. The rotation conditions were 4000 rpm and 15 seconds. After coating
After drying at 100 ° C for 10 minutes, increase the temperature in the oven for 40 minutes and heat treatment at 200 ° C for 90 minutes,
A polyetherimide having a film thickness of about 600 A was obtained. The substrate on which this polyetherimide film was formed was rubbed with a push-in amount of 0.4 mm using rayon cloth with 1.8 mm foot length, and the rubbing directions were parallel and both substrates were oriented in the same direction. Liquid crystal cell was prepared. After heating this liquid crystal cell at 110 ° C, inject the chisso ferroelectric liquid crystal “CS-1031” to increase the temperature from 100 ° C to 70 ° C by 1 ° C /
Orientation was then achieved by slow cooling to room temperature at a rate of minutes. Observing under the initial orientation orthogonal row Nicol of this cell,
The entire surface was twisted. After rubbing the substrate on which the polyetherimide film was formed, cells having a cell thickness of 20 μm were prepared by aligning the rubbing directions in parallel and in different directions, and a liquid crystal composition ZLI-11 manufactured by Merck & Co., Inc.
32 was injected, and isotropic treatment was performed at 120 ° C. for 30 minutes, followed by slow cooling alignment. When this pretilt angle was measured by the crystal rotation method, it was 1.5
It was degree.

[0046]

According to the present invention, it is possible to obtain a ferroelectric liquid crystal device having good orientation, high contrast and bistability.

[0047]

[Brief description of drawings]

FIG. 1 is a diagram showing a helical structure of SmC ^* liquid crystal.

FIG. 2 is a diagram showing a tilt angle of SmC ^* liquid crystal.

FIG. 3 is a diagram showing a phase structure and orientation of SmC ^* liquid crystal.

FIG. 4 is a diagram showing an optical response (uniform orientation) of an SmC ^* liquid crystal element.

FIG. 5: Optical response of SmC ^* liquid crystal element (twist orientation)
FIG.

FIG. 6 is a diagram showing a V-shaped structure of SmC ^* liquid crystal and definitions of C1 and C2 orientations.

FIG. 7 is a diagram showing director profiles of C1U and C2U orientations.

Claims (5)

[Claims] 1. A general formula: An alignment control film for a ferroelectric liquid crystal, which comprises a polymer having a skeleton represented by as a main chain as a main component. 2. A general formula: An alignment control film for a ferroelectric liquid crystal, comprising a polyimide polymer substance having a repeating unit represented by 3. A ferroelectric liquid crystal device using the alignment control film for a ferroelectric liquid crystal according to claim 1 or 2. 4. The ferroelectric liquid crystal device according to claim 3, wherein the ferroelectric liquid crystal device is a liquid crystal light modulation device. 5. The ferroelectric liquid crystal device according to claim 3, wherein the ferroelectric liquid crystal device is a liquid crystal display device.