JPH03209221A - Ferroelectric liquid crystal element - Google Patents

Abstract

PURPOSE:To easily obtain the orientation uniform over the entire surface of the element at a low cost by subjecting a coated film of polyimide to an orientation treatment to form a liquid crystal orientation control film and specifying the film thickness thereof to a specific value or below. CONSTITUTION:Transparent electrodes 12 consisting of an indium tin oxide is formed on a substrate 11 consisting of glass, plastic, etc. After the orientation control film 13 is formed thereon, the film is subjected to the orientation treatment. A sealing resin 14 in common use as a spacer is printed and two sheets of liquid crystal supporting plates 15 are stuck to each other. A liquid crystal 16 is injected from an aperture and the aperture is sealed, by which a ferroelectric liquid crystal cell is produced. The coated film of the polyimide which is subjected to the orientation and has <=200Angstrom film thickness is provided as the orientation control film 13 on at least one liquid crystal supporting plate 11.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a ferroelectric liquid crystal device. Conventional technology As a technique for controlling the orientation of molecules and their aggregates, etc., in liquid crystal devices, a synthetic polymer such as polyimide or boria-based polymer is applied to a substrate, dried, and the surface is rubbed with a cloth. Orientation control films are mainly used, which are subjected to a rubbing process to control the orientation. Further, as a method that does not perform this rubbing treatment, there is an oblique evaporation method of silicon oxide or the like.

Problems to be Solved by the Invention Rubbing treatment, which is one of the methods for controlling the orientation of molecules, etc. in liquid crystal elements, is a simple method that can be carried out at low cost. A polymer coating film made of polyimide, polyamide, etc. with a thickness of about 300 to 1000 is used as an orientation control film.
In liquid crystal devices using ferroelectric liquid crystals that require bistability in the orientation direction of molecules, the i! It had a problem. - On the other hand, as a method for aligning liquid crystal without performing rubbing treatment,
There is a method of wearing oblique wisteria. Using this method, it is possible to manufacture liquid crystal elements with good performance, but the vapor deposition process is complicated and the cost is generally high, making it difficult to reduce the cost, especially for large areas. Above are the means to solve the problem! ! In order to solve the problem, the ferroelectric liquid crystal element of the present invention is provided with a polyimide coating film on at least one of the liquid crystal support plates which has undergone an alignment treatment as an alignment control film and has a thickness of 200 or less. ．． Function The present invention is an alignment system in which the coating film of the bolioid ξ is subjected to an alignment treatment.
An important feature of the 11 film is that its M4 thickness is less than 200 mm, and by making the film thinner in this way, good orientation of molecules and their aggregates can be achieved. Also,
When this is applied to a liquid crystal device, uniform alignment can be easily achieved over the entire surface of the device at low cost. In particular, liquid crystal devices using ferroelectric liquid crystals can achieve uniform alignment at low cost while maintaining complete bistability. EXAMPLE Hereinafter, an alignment control film according to an example of the present invention and a liquid crystal device using the same will be described with reference to the drawings. 1st
The figure is a schematic diagram of a liquid crystal device using the alignment control film of the present invention. A transparent electrode 12 made of indium/tin oxide is formed on a substrate 11 such as glass or brass tink, an alignment control film 13 is formed thereon and then subjected to alignment treatment, a spacer/sealing resin 14 is printed, and 2 Two liquid crystal support plates 15 were pasted together, liquid crystal 16 was injected through the opening, and the opening was sealed to produce a so-called ferroelectric liquid crystal cell. In order to improve the bistability of the ferroelectric liquid crystal element, which had achieved such success, stearylamine, triphenylamine, cyclohexylamine, and diphenylamine were added to the ferroelectric liquid crystal to be injected. Methyldiphenylamine, penzylamine, methylbenzylamine, dimethylbenzylamine, phenylethylamine.
Phenylpubiruamine, benzylethanolamine,
Phenyldiethanolamine, 1.1'-(phenylimino)di-2-probanol, diphenyl, diviridyl. One type of amine of polyoxypropylene polyamine or a mixture of several types thereof may be added as an additive. Example 1 A commercially available polyimide (RN7 1 5 manufactured by Nissan Chemical Co., Ltd.) was diluted with a special thinner to prepare a 0.3% by weight polyimide solution. Next, this solution was spin-coated for 1 minute at 2500 rpm on a glass substrate with an ITO electrode pattern. The coating was dried in i80'C for 15 minutes to evaporate the solvent, and then dried in an electric furnace at 250'C for 1 hour. The surface was rubbed 10 times in the same direction using a rayon cloth to completely form the alignment control film.Two glass liquid crystal support plates with polyimide alignment control films formed thereon were prepared in this way, as shown in Figure 2. On the surface of one of the supporting plates (for example, the lower liquid crystal supporting plate 22) on which the alignment control film is formed, a substrate and sealing resin 25 with a diameter of 2
Acid anhydride-curing epoxy resin with μm glass fibers dispersed in it leaves a width of 5M in the center of one side and 0.5M in the other periphery.
．． The rubbing direction 23 of the alignment control film printed on the upper liquid crystal support plate 2l and the lower support plate 22 after printing with a width of 2 sheets
．． 24 were parallel and the orientation control film surfaces faced each other, pressure was applied, and the film was heated at 140°C for 4 hours to cure and bond. After adhesion, the liquid crystal is heated to a temperature at which it exhibits isotropy, that is, around 80°C, and the liquid crystal (manufactured by Merck & Co., Ltd., product name zt, r3) is inserted through the opening.
654) was injected. After injection, it was slowly cooled to room temperature and the opening was sealed with a commercially available acid anhydride-curing epoxy resin, completing the ferroelectric liquid crystal cell. The ferroelectric liquid crystal cell that was successfully completed in this way exhibited good alignment with no alignment unevenness or rubbing streaks, and when voltage was applied, good electro-optical properties with guaranteed bistability were obtained. Example 2 A commercially available polyimide (RN715 manufactured by Nissan Chemical Co., Ltd.) was diluted with a special thinner to prepare a 1.0% by weight polyimide solution. Next, this solution was spin-coated for 1 minute at 2500 rpm on a glass substrate with an ITO electrode pattern formed thereon. After coating, the coating was dried at 80°C for 15 minutes to evaporate the solvent, and then dried in an electric furnace at 250°C for 1 hour. V. There were 200 people. The ferroelectric liquid crystal cell prepared by the same operation as in the specific example below shows a good alignment state with no alignment unevenness or rubbing streaks, and when a voltage is applied, good electro-optic properties with bistability are ensured. Obtained. Example 3 0.1% by weight of stearylamine was added as an additive to a ferroelectric liquid crystal cell prepared using commercially available polyimide (RN7 1 5 manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1.
The added liquid crystal (manufactured by Merck & Co., trade name: ZLI3654) was injected. The ferroelectric liquid crystal cell that has been perfected in this way exhibits a good alignment state with no alignment unevenness or rubbing streaks, and when voltage is applied, good electro-optical properties with guaranteed bistability can be obtained. Bistability was ensured over the period.

Example 4 A strong V, conductive liquid crystal cell was prepared using commercially available polyimide (RN715 manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1, and a liquid crystal cell was prepared by adding 0.3% by weight of benzylamine as an additive ( The thus completed ferroelectric liquid crystal cell injected with ZLl3654 (manufactured by Merck & Co., Ltd.) showed a good alignment state with no alignment unevenness or rubbing streaks, and bistability was ensured by applying a voltage. Good electro-optical properties were obtained, and bistability was ensured for a long period of time. Example 5 0.1% of polyoxybrobylene diamine having a molecular weight of 1400 was added as an additive to a ferroelectric liquid crystal cell prepared using commercially available polyimide (RN715 manufactured by Nissan Chemical Industries, Ltd.) in the same manner as in Example 1. liquid crystal (manufactured by Merck & Co., Ltd.)
The product (trade name: ZLI3654) was injected. The ferroelectric liquid crystal cell that has been perfected in this way shows a good alignment state with no alignment unevenness or rubbing streaks, and when voltage is applied, good electro-optical properties with ensured bistability can be obtained, and furthermore, it can be used for a long time. Bistability was ensured over the period.

Example 6 Using a commercially available polyimide (RN7 1 5 manufactured by Nissan Chemical Co., Ltd.), a strong readable liquid crystal cell was prepared in the same manner as in Example 1, and 0.3% of boroxypropylene diamine with a molecular weight of 230 was added as an additive. A liquid crystal (manufactured by Merck & Co., trade name: ZLI3654) containing % by weight was injected. The ferroelectric liquid crystal cell that has been perfected in this way shows a good alignment state with no alignment unevenness or rubbing streaks, and when voltage is applied, good electro-optical properties with ensured bistability can be obtained, and furthermore, it can be used for a long time. Bistability was ensured over the period. Example 7 Commercially available polyimide (SE4110 manufactured by Nissan Chemical Co., Ltd.) was diluted with a special thinner to prepare a 0.3% by weight polyimide solution. Thereafter, spin coating was performed under the same conditions as in Example 1 to form a polyimide coating on the glass substrate on which the ITO pattern had been formed. The film thickness was 60 pieces. Thereafter, in the same manner as in Example 1, liquid crystal (manufactured by Merck & Co., trade name: ZLI3654) was injected into the prepared ferroelectric liquid crystal cell. Is this the kind of coercion that you have completely warned yourself about? It? '． The JE liquid cell showed a good alignment state with no alignment unevenness or rubbing streaks, and when voltage was applied, good electro-optical properties with ensured bistability were obtained. Example 8 Commercially available polyimide (SE4 1 1 0 manufactured by Nissan Chemical Co., Ltd.)
was diluted with a special thinner to prepare a 1.0% by weight polyimide solution. Thereafter, spin coating was performed under the same conditions as in Example 1 to coat the glass substrate with the ITO pattern. ! ! The membrane was shaped. The film thickness was 200 people. Thereafter, by the same operation as in Example 1, a liquid crystal (manufactured by Merck & Co., trade name: ZLI365) was added to the produced ferroelectric liquid crystal cell.
4) was injected. The ferroelectric liquid crystal cell that was successfully completed in this way showed a good alignment state with no alignment unevenness or rubbing streaks, and when voltage was applied, good electro-optical properties with ensured bistability were obtained. Example 9 A ferroelectric liquid crystal cell was prepared using a commercially available polyimide (SE4110 manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1, and a liquid crystal cell was prepared by adding 0.1% by weight of stearyl amine as an additive ( Merck & Co., trade name ZLI3654) was injected. The ferroelectric liquid crystal cell that achieved complete success in this way was
Shows a good orientation state with no orientation unevenness or rubbing streaks,
By applying a voltage, good electro-optical properties with bistability were obtained.Furthermore, bistability was ensured for a long period of time.

Example 10 A ferroelectric liquid crystal cell was prepared using a commercially available polyimide (SE4110 manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1, and a liquid crystal cell (Merck's SE4110) to which 0.3% benzylamine was added as an additive was added. (trade name: ZLI3654) was injected. The ferroelectric liquid crystal cell that has been perfected in this way shows a good alignment state with no alignment unevenness or rubbing streaks, and when voltage is applied, good electro-optical properties with ensured bistability can be obtained, and furthermore, it can be used for a long time. During the period l-) and double stability were ensured.

Example 11 A ferroelectric liquid crystal cell was prepared using a commercially available polyimide (SE4 1 10, manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1, and boroxybrobylenedia with a molecular weight of 400 was added as an additive. A liquid crystal (manufactured by Merck & Co., trade name: ZLI3654) containing 0.1% by weight of was injected. The iA dielectric liquid crystal cell completed in this way has no alignment unevenness and no ripples.
It shows a good orientation without any streaks, and by applying an electric current,
Good electro-optical properties with bistability were obtained, and bistability was maintained for a long period of time.

Example 12 0.3 weight of polyoxypropylene diamine having a molecular weight of 230 was added as an additive to a ferroelectric liquid crystal cell prepared in the same manner as in Example 1 using commercially available polyimide (SE4 1 10 manufactured by Nissan Chemical Co., Ltd.). % liquid crystal (manufactured by Merck & Co., trade name: Z L 1 3 6 5 4) was injected. The ferroelectric liquid crystal cell completed in this way (1) showed a good alignment state with no alignment unevenness or rubbing streaks, and when voltage was applied, good electro-optical properties with bistability were obtained. Bistability was ensured for a long period of time.

Comparative Example 1 A commercially available polyimide (RN715 manufactured by Nissan Chemical Co., Ltd.) was diluted with a special thinner to prepare a 1.5% by weight polyimide solution. Thereafter, spin coating was performed under the same conditions as in Example 1 to form a polyimide coating on the glass substrate on which the IT◯ pattern had been formed. The film thickness was 300 people. Following the same operations as in Example 1, the fabricated ferroelectric liquid crystal cell showed a twisted alignment state, and no bistability was achieved even after voltage application. Comparative Example 2 A commercially available polyimide (RN715 manufactured by Nissan Chemical Co., Ltd.) was diluted with a special thinner to prepare a 3.0% by weight polyimide solution. Thereafter, spin coating was performed under the same conditions as in Example 1 to form a polyimide coating on the glass substrate with the ITO pattern. The film thickness was 500 mm.
The i@dielectric liquid crystal cell produced by the same operations as in Example 1 exhibited a twisted alignment state and did not achieve bistability even after voltage application.

Comparative Example 3 A commercially available polyimide (SE4110 manufactured by Nissan Chemical Co., Ltd.) was diluted with a special thinner to prepare a 1.5% by weight polyimide solution. Thereafter, spin coating was performed under the same conditions as in Example 1 to form a polyimide coating on the glass substrate on which the ITO pattern was formed.

The film thickness was 300 people. Following the same procedure as in Example 1, the ferroelectric liquid cell produced exhibited a twisted orientation, and no bistability was achieved even after voltage application. Comparative Example 4 Commercially available polyimide (SE4110 manufactured by Nissan Chemical Co., Ltd.) was diluted with a special thinner, and 3. A solution of 0 ffiff% polyimide was prepared. Thereafter, spin coating was performed under the same conditions as in Example 1 to form a polyimide coating on a glass substrate with an ITO pattern. The film thickness was 500 pieces. Following the same operations as in Example 1, the produced ferroelectric liquid crystal cell showed a twisted alignment state and did not achieve bistability even after voltage application.

Comparative Example 5 0.5% by weight of stearylamine was added as an additive to a ferroelectric liquid crystal cell prepared in the same manner as in Example 1 using commercially available polyimide (RN7 1 5 manufactured by Nissan Chemical Co., Ltd.).
Added liquid crystal (manufactured by Merck & Co., trade name: Z L I 3 6
5 4) was injected. The ferroelectric liquid crystal cell that was successfully developed in this way could not achieve uniform alignment.

Comparative Example 6 A ferroelectric liquid crystal cell was prepared using commercially available polyimide (RN715, manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1, and a liquid crystal cell was prepared by adding 0.5% of Henzilagon as an additive. Merck & Co., trade name ZLl3654) was injected. The ferroelectric liquid crystal cell that was successfully developed in this way could not achieve uniform alignment. Comparative Example 7 A ferroelectric liquid crystal cell was prepared using commercially available polyimide (RN715 manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1, and 0.00% of boroxybrobylene diamone with a molecular ffi of 400 was added as an additive. A liquid crystal (manufactured by Merck & Co., trade name: ZLI3654) containing 5ffifft% was injected. The ferroelectric liquid crystal cell completed in this way did not have uniform alignment.

Comparative Example 8 A ferroelectric liquid crystal cell was prepared using commercially available polyimide (RN715 manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1, and 0.5% of voriquine propylene diamine with a molecular weight of Mt230 was added as an additive. % added liquid crystal (manufactured by Merck & Co., Ltd.,
(trade name: ZLI3654) was injected. The ferroelectric liquid crystal cell that was successfully developed in this way could not achieve uniform alignment.

Comparative Example 9 A ferroelectric liquid crystal cell was prepared using commercially available polyimide (SE4110 manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1, and 0.5% by weight of stearylamine was added as an additive to a liquid crystal cell (Merck & Co. (trade name: ZLI3654) was injected. The ferroelectric liquid crystal cell completed in this way is
Uniform orientation could not be obtained.

Comparative Example 10 A ferroelectric liquid crystal cell was prepared using commercially available polyimide (SE4110 manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1, and a liquid crystal cell (Merck & Co., Ltd.) in which 0.5% by weight of benzylamine was added as an additive was added. (trade name: ZLI3654) was injected. The ferroelectric liquid crystal cell completed in this way did not have uniform alignment. Comparative Example 11 0.5% by weight of boroxybrobylene diamine having a molecular weight of 400 was added as an additive to a ferroelectric liquid crystal cell prepared in the same manner as in Example 1 using commercially available polyimide (SE4110 manufactured by Nissan Chemical Co., Ltd.). Added liquid crystal (manufactured by Merck & Co., Ltd.,
The product (trade name: ZLI3654) was injected. The ferroelectric liquid crystal cell completed in this way did not have uniform alignment. Comparative Example 12 0.5% polyoxypropylene diamine having a molecular weight of 1230 was added as an additive to a ferroelectric liquid crystal cell prepared using commercially available polyimide (SE4110 manufactured by Nissan Chemical Co., Ltd.) in the same manner as in Example 1. Added liquid crystal (manufactured by Merck & Co., Ltd.)
(trade name: ZLI3654) was injected. The ferroelectric liquid crystal cell completely discharged in this manner did not have uniform alignment.

In the above examples, the surface of the polyimide formed on the transparent electrode was directly rubbed, but in the present invention, the surface of the polyimide formed on the silicon oxide etc. formed on the transparent electrode to prevent short circuits was rubbed. It can also be applied in cases.

Effects of the Invention As described above, the present invention applies alignment treatment to a polyimide coating film to form a liquid crystal alignment control film, and by making the film thickness 200 or less, it is possible to control the orientation of molecules and their aggregates, etc. become. Furthermore, when applied to liquid crystal devices, uniform alignment can be easily achieved over the entire surface of the device at low cost.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a liquid crystal device of the present invention, and FIG. 2 is a schematic diagram of a strong electrostatic liquid crystal device using the alignment control film and alignment control method of the present invention. l1...substrate, 12...transparent electrode layer,
13...Alignment control film, l4...Spacer/sealing resin, 15...Liquid crystal support plate, 16.
...Liquid crystal, 2l... Upper liquid crystal support plate, 2
2...' F-side liquid crystal support plate, 23... Upper liquid crystal support plate rubbing direction, 24... Lower liquid crystal support plate rubbing direction, 25...・・・Subasa and sealing resin.

Claims (3)

[Claims] (1) An alignment control film characterized in that the alignment control film is a polyimide coating film, the coating film has been subjected to an alignment treatment, and the film thickness is 200 Å or less, and the liquid crystal element has at least one A ferroelectric liquid crystal element, characterized in that a ferroelectric liquid crystal substance is held in a space between a pair of liquid crystal supporting plates facing each other, each of which has a polyimide alignment control film as described above on a substrate. (2) The ferroelectric liquid crystal element according to claim (1), wherein the liquid crystal substance held in the opposing interval between the liquid crystal support plates is a pyrimidine liquid crystal and exhibits ferroelectricity. (3) The ferroelectric liquid crystal element according to claim (2), wherein the liquid crystal substance contains an amine compound as an additive.