JPH02242222A - Production of optical liquid crystal device - Google Patents

Abstract

PURPOSE:To continuously produce optical liq. crystal devices of a large area and to enhance productivity by using a gravure coater when a substrate is coated with a liq. crystal material and an adhesive. CONSTITUTION:When a substrate is coated with a liq. crystal material and an adhesive, pattern printing is carried out with a gravure coater fitted with a gravure roll A. The roll A is rotated in a direction reverse to the direction of travelling of the substrate and the linear velocity of the roll A is regulated to 1.5-100 times, preferably 2-50 times as high as the speed of the substrate so as to control the thickness of a coating layer. A roll B is set vertically movably with an air cylinder, brings the substrate into contact with the roll A and enables intermittent coating. A roll C presses the substrate against the roll A and can evaporate a solvent when heated to about 100 deg.C. Such coated substrates are laminated and orientation is carried out by bending or other method. Optical liq. crystal devices is continuously produced.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing a liquid crystal optical element, and more specifically, to a method for continuously manufacturing a liquid crystal optical element that can be suitably used as a liquid crystal display element, a liquid crystal recording element, etc. The present invention relates to a method for easily manufacturing liquid crystal optical elements.

[Conventional technology]

Liquid crystal optical elements that utilize the electro-optic and thermo-optic effects of liquid crystals are used in liquid crystal displays, liquid crystal shutter arrays,
Widely used in liquid crystal printers, etc. Conventionally, the method for manufacturing liquid crystal optical elements was to stack the two substrates that make up the liquid crystal optical element with a spacer in between, glue and seal the periphery leaving a liquid crystal injection hole, and then inject liquid crystal. was. However, this method has problems such as it is difficult to maintain the thickness of the liquid crystal layer at several micrometers, and it is also difficult to inject the liquid crystal.
Improved methods such as those described in Japanese Patent No. 7720 have been proposed. In this method, a liquid crystal material containing a spacer is applied to a substrate under reduced pressure by screen printing, but it is difficult to achieve continuity with screen printing, and
There is a problem in that the process is complicated because it is operated in a reduced pressure chamber.

[Problem to be solved by the invention]

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a method for manufacturing a liquid crystal optical element, which allows liquid crystal optical elements to be manufactured continuously by simple operations.

Another object of the present invention is to provide a method for manufacturing a liquid crystal optical element having a uniform liquid crystal thin film with a large area and large capacity display.

[Means to solve the problem]

As a result of extensive research in order to solve the above problems, the present inventors have discovered that by applying liquid crystal material and/or adhesive to a substrate using a gravure coater, a large area of liquid crystal material can be applied to the substrate. Furthermore, the inventors have discovered that uniform coating can be easily performed and continuous production of liquid crystal optical elements is possible, and based on this knowledge, the present invention has been completed.

That is, the present invention provides a method for manufacturing a liquid crystal optical element, which includes a step of pattern-printing a liquid crystal material and/or adhesive onto a substrate using a gravure coater.

FIG. 1 is a schematic diagram showing an example of a set of gravure coaters used in the present invention, and A is a gravure roll that rotates in the opposite direction to the flow direction of the substrate.

The linear velocity v2 of the gravure surface during rotation of the gravure roll is
Usually 1.5 to 100 times the moving speed v1 of the substrate,
Preferably, it is set to 2 to 50 times. In addition, by changing the rotation speed of this gravure roll,
The thickness of the pattern-printed liquid crystal material and/or adhesive coating layer can be controlled. Roll B is an intermittent application mechanism for performing pattern printing intermittently, and can be moved up and down by an air cylinder, and pattern printing can be performed intermittently by bringing gravure roll A into or out of contact with the substrate. I can do it. Roll C is a roll for pressing the substrate against gravure roll A, and if necessary a heating device is installed and heated to about 100'C to evaporate the solvent used during coating.

A pattern of liquid crystal material is printed on a substrate using such a gravure coater. Further, when a counter substrate is laminated with an adhesive on a substrate on which a pattern of liquid crystal material is printed, the pattern of the adhesive is printed on the substrate or the counter substrate using the gravure coater.

A liquid crystal optical element is obtained by stacking the substrates thus obtained and subjecting them to alignment treatment such as bending alignment treatment. When an adhesive is contained in the liquid crystal material, the substrates can be laminated without applying an adhesive to the opposing substrate.

FIG. 2 is a schematic illustration showing a printing pattern when applying a liquid crystal material onto a substrate using a set of gravure rolls shown in FIG. 1, in which 1 is a gravure roll, 2 is a substrate, and 3
is the surface to which the liquid crystal material is applied intermittently. 3 and 4 are schematic explanatory diagrams showing printing patterns when applying adhesive using another gravure roll, and 4.6
2 is a gravure roll, 2' is a counter substrate, and 5.7 is an adhesive coating surface. After applying a line to the area corresponding to the outside of the liquid crystal material application surface as shown in Figure 3, the adhesive application is completed by applying intermittently to the non-applied surface between the liquid crystal application surfaces as shown in Figure 4. . By combining these coating operations shown in FIGS. 2 to 4, the arrangement of the liquid crystal material coated surface and the adhesive coated surface as shown in FIG. 5 is constructed. The liquid crystal material and adhesive may be applied to the same substrate, or may be applied separately to each opposing substrate. The substrate coated with the liquid crystal material thus obtained and the counter substrate coated with adhesive are laminated and sent to the next alignment step.

By applying the liquid crystal material and adhesive using multiple gravure rolls, it is possible to pattern and apply the liquid crystal material and adhesive separately, making it easy to manufacture liquid crystal optical elements with desired configurations. . In the present invention, the substrate to which the liquid crystal material or adhesive is applied is usually a long one, and is continuously supplied to a gravure coater for coating. This allows continuous production of liquid crystal optical elements,
It is possible to easily increase the area. The material of the board is usually selected from the viewpoint of productivity, versatility, workability, etc.
A substrate made of plastic having excellent heat resistance, transparency, durability, etc. is preferably used. Specific examples include crystalline polymers such as -axially or biaxially stretched polyethylene terephthalate, amorphous polymers such as polysulfone and polyethersulfone, polyolefins such as polyethylene and polypropylene, and plastic substrates such as polycarbonates and polyamides such as nylon. It will be done. When a plastic substrate is used, the weight can be reduced compared to when a glass substrate is used.

A transparent electrode is provided on the substrate, and a NESA film coated with tin oxide, an ITO film made of tin oxide and indium oxide, or the like is used as the transparent electrode. These electrodes can be provided on the substrate using various known methods, such as sputtering, vapor deposition, printing, coating, plating, adhesion, etc., or an appropriate combination of these methods. can.

The liquid crystal material used in the present invention is not particularly limited as long as it exhibits liquid crystallinity, but includes low molecular weight nematic liquid crystal,
Low molecular cholesteric crystal, low molecular smectic liquid crystal,
Examples include polymer nematic liquid crystal, polymer cholesteric liquid crystal, polymer smectin liquid crystal, and mixtures thereof. Low-molecular and high-molecular liquid crystal materials exhibiting ferroelectricity and mixtures thereof can also be suitably used. Further, the liquid crystal material used in the present invention may contain additives such as pleochroic dyes and thinners, adhesives, etc. in addition to the above-mentioned polymer liquid crystals and low molecular liquid crystals.

Examples of pleochroic dyes include styryl, azomethine, azo, naphthoquinone, anthraquinone, merocyanine, benzoquinone, and tetrazine dyes.

The adhesive used in the present invention may be used alone or mixed into a liquid crystal material.
The following polymeric substances commonly used as adhesives may be mentioned, such as epoxy adhesives, acrylic adhesives, polyurethane adhesives, hot melt adhesives, and elastomer adhesives.

The liquid crystal material and adhesive are solvents such as dichloromethane, chloroform, methyl ethyl ketone, 1,1,1-trichloroethane, toluene, and/or mixtures thereof, and usually have a concentration of 2 to 70% by weight, preferably 2 to 50% by weight.
It is diluted to % by weight and applied using a gravure coater.

The substrates coated as described above are laminated using a pressure roll or the like, then subjected to orientation treatment such as bending orientation treatment, and then cut to form a liquid crystal optical element.

These coating, laminating, alignment, and cutting processes can be made continuous, allowing large-area liquid crystal optical elements to be produced continuously without the need for complicated processes, and making it possible to reduce the cost of liquid crystal optical elements. becomes.

[Examples] Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited thereto.

Example 1 Diluted liquid (A) A diluted crude liquid (A) was obtained by adjusting a ferroelectric polymer liquid crystal having the following repeating unit to a concentration of 15% by weight with dichloromethane.

Mn=5. 300 (cry: crystalline phase, Smc”: chiral smectic C phase, StmA: smectic A phase, Iso
: Tokichi phase] Dilute crude liquid (B) A diluted liquid made by adjusting the concentration of epoxy resin manufactured by Yuka Shell Epoxy ■ (mixture of base material Epicoat 834 and curing agent QX-11 at a weight ratio of 2:1) with toluene to 5% by weight. (B) was obtained.

The above diluted solutions (A) and (B) were applied to a PES (polyethersulfone) substrate with ITO (thickness: 125 μm, width: 15 cm, length: 50 m) using a gravure coating device configured as shown in Figure 6.
(rolled material) respectively, and after solvent evaporation, the thickness was 3.
A 1 μm film was obtained.

The specifications of the device shown in FIG. 6 are as follows.

Roll A Gravure shape Trapezoid 75 mesh diameter 25 plates φ Rotation speed 200 rpm v2415.7 m/min Coating target Diluent (A) Coating area As shown (Unit of numerical value: rMl) Intermittent operation Coating time 4.4 seconds Pausing time 1 second Roll A ' Gravure shape Trapezoid 1.50 mesh Diameter 25IIIllφ Rotation speed 100100 rp = 7.9 m/min Coating target Diluted liquid CB) Coating area As shown (Numeric unit: mm) Intermittent operation
Blank roll A' Gravure shape Trapezoid 150 mesh Diameter 25mmφ Rotation speed 100100 rpm 7.9m/min Coating target Diluent (B) Coating area As shown (Numeric unit: aa) Intermittent operation
Coating time: 0.9 seconds Pause time: 4.5 seconds Substrate speed: v+=2 m/min A set of substrates obtained in this way was stacked with the coated surfaces together using a roll, and then the substrates were stacked with a diameter of 30 m1 and a distance between centers of 40 ffI. [Bending and orientation treatment was performed continuously using a roll group consisting of three rolls of II.

Next, the obtained long liquid crystal panel was cut into two parts at the adhesive coated part to obtain a panel of a desired size.

When the contrast of the obtained liquid crystal panel was measured at room temperature, a good alignment state of 28 was obtained by applying ±5 μ, and the display was maintained for more than 24 hours even when the electric field was turned off. As described above, the method of the present invention enables continuous production of long objects (coating → lamination → alignment treatment → cutting), greatly improving productivity, and easily producing liquid crystal display elements with good contrast. was gotten.

Examples 2 to 6 In Example 1, a liquid crystal display element was produced in the same manner as in Example 1 except that the substrate speed, gravure roll mesh, and rotation speed were changed as shown below. A liquid crystal display element with the performance as shown was obtained.

Example 7 Coating to a substrate was carried out in the same manner as in Example 1, except that the coating target was changed as follows.

Diluent (A) Ferroelectric polymer liquid crystal I Mn=15. 000 [g-niglass state, Sl: unidentified smecti binary phase] Ferroelectric polymer liquid crystal ■ Mn = = 3,000 Shogami IIL drink The above two types of polymer liquid crystals I and ■ were mixed in a ratio of 50:50 (mol% )
The mixture was dissolved in acetone to obtain a 10% by weight diluted solution (A).

Diluent (B) A curable acrylic adhesive (manufactured by Cemedine ■, Cemerox Super Y-862-1) was dissolved in MEK (methyl ethyl ketone) to obtain a 10% by weight diluted solution (B).

After coating and evaporating the above diluted solutions (A) and (B) in the same manner as in Example 1, a 2.5 μm film was obtained.

After the respective substrates were laminated and subjected to orientation treatment, they were irradiated with a 400W metal halide lamp for about 2 seconds and cut to obtain a desired panel.

When the contrast of the obtained liquid crystal panel was measured at room temperature, a value of 36 was obtained when ±5 V was applied.

Example 8 Coating was carried out under the same conditions as in Example 1, except that the coating target was changed as follows.

Diluted Solution (A) A diluted solution (A) was obtained by adjusting the following low-molecular-weight ferroelectric liquid crystal to a concentration of 15% by weight with dichloromethane.

After evaporation of the solvent, a 2.1 μm film was obtained, and laminated and oriented in the same manner as in Example 1 to obtain a desired panel.

When the contrast of the obtained liquid crystal panel was measured at room temperature, a value of 23 was obtained with an application of ±5 μ.

Example 9 Application to a substrate was carried out in the same manner as in Example 1, except that the diluent (A) to be applied was changed as follows.

Diluted solution (A) A: B: C: D=45.6:30.4:4:
20A CH! (mol %) After evaporation of the solvent, a 2.9 μm film was obtained, and laminated and oriented in the same manner as in Example 1 to obtain a desired panel.

When the contrast of the obtained liquid crystal panel was measured at room temperature, a value of 70 was obtained with an application of ±9 square meters.

Example 10 Ferroelectric polymer liquid crystal Mn = 5 30 0 Mn - 3,000 Adhesive Epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd. (mixture of base material Epicoat 834 and curing agent QX-11 in a weight ratio of 2:1) Repeating the above A liquid crystal composition in which a polymeric liquid crystal having units and an adhesive were mixed at a weight ratio of 50,750 was dissolved in dichloromethane to form a 15% by weight solution.

The above solution was IT coated with a gravure coating device having the configuration shown in Fig.
Each of these was applied to a PES substrate with O (a roll of 125 μm in thickness, 15 cm in width, and 50 m in length), and a film with a thickness of 3.1 μm was obtained after solvent evaporation.

The specifications of the device shown in FIG. 7 are as follows.

Roll A Gravure shape Trapezoid 75 mesh Diameter 25mmφ Rotation speed 20Orpm Vz = 15.7m/mtn Application area above solution application area As shown (Numeric unit: aa) Intermittent work
Coating time: 4.4 seconds Pausing time: 1 second Substrate speed: V + "" 2 m/min The plates were stacked and laminated using a roll, and then the bending and orientation treatment was performed in the same manner as in Example 1. Next, the obtained long liquid crystal panel was cut to obtain a panel of a desired size.

When the contrast at room temperature of the obtained liquid crystal panel was measured, a good alignment state of 23 was obtained with an application of ±5 square meters, and the display was maintained for more than 24 hours even when the electric field was turned off. As described above, the method of the present invention enables continuous production of long objects (coating → lamination → alignment treatment → cutting), greatly improves productivity, and easily produces liquid crystal display elements with good contrast. Obtained.

Examples 11 to 14 In Example 10, a liquid crystal display element was produced in the same manner as in Example 10, except that the substrate speed, gravure roll mesh, and rotation speed were changed as shown below. A liquid crystal display element with the performance as shown was obtained.

The coating surface of the thus obtained substrate was coated with an opposing group.Table 2 Example 15 Coating to the substrate was carried out in the same manner as in Example 10, except that the coating object was changed as follows.

Ferroelectric polymer liquid crystal I H3 Mn=15. 000 Ferroelectric polymer liquid crystal■ Mn=3. 000 A UV-curable acrylic adhesive (manufactured by Cemedine ■, Cemerox Super Y-862-1) was added to a mixture of the above two types of polymeric liquid crystals I and ■ at a ratio of 50:50 (mol%).
were mixed at a weight ratio of 3:1 and dissolved in acetone to give a concentration of 10% by weight.
A solution of was obtained. Using this solution, a film of 2.5 μm was obtained after coating and evaporation in the same manner as in Example Process 0. A counter substrate was laminated on the coated surface, and after alignment treatment, irradiation with a 400W metal halide lamp was performed for about 2 seconds. , and cut to obtain the desired panel.

When the contrast of the obtained liquid crystal panel was measured at room temperature, a value of 30 was obtained when ±5V was applied.

Example 16 Coating was carried out under the same conditions as in Example 10, except that the coating object (polymer ferroelectric liquid crystal) was changed as follows.

After evaporation of the IF filter solvent, a 2.1 μm film was obtained, which was laminated and oriented to form a desired panel.

When the contrast of the obtained liquid crystal panel was measured at room temperature, a value of 13 was obtained when ±5 V was applied.

Example 17 Coating to a substrate was carried out in the same manner as in Example 10, except that the coating object (ferroelectric polymer liquid crystal) was changed as follows.

A: B: C: D -45,6:30.4:4
:20 (mol%) A CHtsu! B [Effects of the Invention] According to the manufacturing method of the present invention, liquid crystal optical elements with a large area and large display capacity can be manufactured easily and continuously through simple steps, and productivity is greatly improved. By doing so, it becomes possible to reduce the manufacturing cost of the liquid crystal optical element.

Further, according to the manufacturing method of the present invention, the film thickness can be easily adjusted and a uniform thin film can be obtained.

After evaporating the Mn-3000 solvent, a 2.9 μm film was obtained, which was laminated and oriented in the same manner as in Example 10, and then cut into desired panels.

When the contrast of the obtained liquid crystal panel was measured at room temperature, a value of 55 was obtained with an application of ±9 square meters.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a gravure coater used in the manufacturing method of the present invention, and FIGS. 2, 3, 4, and 5 are schematic cross-sectional views showing the state of the coating film. FIG. FIGS. 6 and 7 are schematic explanatory views showing the manufacturing process of the present invention and the state of the coating film.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a liquid crystal optical element, comprising the step of pattern printing a liquid crystal material and/or adhesive onto a substrate using a gravure coater. 2. The method for manufacturing a liquid crystal optical element according to claim 1, wherein the liquid crystal material and/or the adhesive are diluted with a solvent. 3. The method for manufacturing a liquid crystal optical element according to claim 1, wherein continuous production is performed by using a roll-shaped flexible base material as the substrate. 4. The method for manufacturing a liquid crystal optical element according to claim 1, wherein the pattern printing on the substrate is performed intermittently. 5. By rotating the gravure roll of the gravure coater in the opposite direction to the flow direction of the substrate and changing the rotation speed so that the linear velocity of the gravure surface is 1.5 to 100 times the flow velocity of the substrate, 5. The method for manufacturing a liquid crystal optical element according to claim 1, wherein the film thickness of the pattern-printed liquid crystal material and/or adhesive is controlled. 6. The method for manufacturing a liquid crystal optical element according to claim 1, wherein the liquid crystal material and/or adhesive is pattern-printed on the substrate using a plurality of gravure coaters having different gravure roll shapes.