JP2952148B2 - Liquid crystal optical element and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal optical element suitably used in the field of optoelectronics as a liquid crystal display element, a liquid crystal storage element, a liquid crystal acoustic element, a light control glass, and the like, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A ferroelectric liquid crystal has attracted attention as a liquid crystal material of a liquid crystal optical element because of its high-speed response and memory properties. However, when manufacturing a liquid crystal optical element by a normal method of injecting a liquid crystal material between glass substrates, there is a problem that it is difficult to increase the area and the yield is low. On the other hand, if a flexible substrate (eg, a plastic film) is used as the substrate, a series of continuous processes such as film formation of a liquid crystal, lamination with a counter substrate, and bending alignment can be used. An optical element can be easily manufactured. However, in the obtained liquid crystal optical element, since the substrate has flexibility, a conduction defect is easily generated by pressing or the like. In order to prevent the defect, it is necessary to strengthen the liquid crystal layer by some method.

[0003] Japanese Patent Application Laid-Open No. 4-199128 describes a method in which a mixture of a polymer material and a spacer is selectively adhered to an arbitrary position through a mask opening to maintain a distance between substrates. However, in this method, the size of a substrate that can be handled is limited by the size of a mask (screen printed matter), and thus there is a problem that an element having a size of a meter or more cannot be usually manufactured. Also, it is necessary to attach or fix the spacer material,
There is also a problem that it is necessary to increase the number of steps independent of a normal element manufacturing step.

Japanese Patent Application Laid-Open No. 4-338724 discloses a method of forming a member for fixing a spacer at a predetermined position on a substrate and fixing the spacer.
Complicated steps such as formation of a fixing member by printing or the like, dispersion of spacers, and curing of the fixing member are required.

Japanese Patent Application Laid-Open No. 2-73219 discloses a method in which a thermoplastic resin is mixed with a ferroelectric liquid crystal and the thermoplastic resin is used as a reinforcing material for a panel. However, this method has a problem that the mechanical strength is inferior to the case where the spacer is mixed in the liquid crystal layer. Further, if it is desired to have the same strength as that in the case where the spacer is inserted, it is necessary to increase the amount of the thermoplastic resin, and there is a problem that the contrast ratio is lowered.

[0006]

SUMMARY OF THE INVENTION The present invention provides a ferroelectric liquid crystal optical element in which at least one of the opposing substrates has flexibility, which liquid crystal optical element has excellent mechanical strength. The purpose is to do so. Further, the present invention can manufacture the liquid crystal optical element by a simplified manufacturing process regardless of the size of the area,
It is an object of the present invention to provide a manufacturing method which has a good yield and enables cost reduction.

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a non-liquid crystalline high liquid crystal layer is formed in a ferroelectric liquid crystal layer composed of a mixture of a ferroelectric polymer liquid crystal and a ferroelectric low molecular liquid crystal. In addition to the mixture of molecular materials, the contrast ratio can be improved by interposing an insulating film made of a non-liquid crystalline polymer material that has adhesiveness to the non-liquid crystalline polymer material in the liquid crystal layer between the liquid crystal layer and the substrate. It has been found that it is possible to improve the mechanical strength of the liquid crystal layer and the panel without lowering the liquid crystal layer and to prevent alignment defects and conduction defects. In such a liquid crystal optical element, the formation of the liquid crystal layer and the insulating film can be performed by a simple operation of coating, and does not require a complicated process. In addition, the present inventors further improved the mechanical strength of the liquid crystal optical element by a simple method by using a solution of a non-liquid crystalline polymer material mixed with a spherical spacer material when forming the insulating film by coating. They have found that they can be improved, and have completed the present invention based on these findings.

In other words, the present invention relates to a liquid crystal optical element in which a ferroelectric liquid crystal layer is sandwiched between two substrates with electrodes, at least one of which has flexibility, on at least one of the substrates provided with electrodes. A ferroelectric liquid crystal layer composed of a mixture of a ferroelectric polymer liquid crystal and a ferroelectric low molecular weight liquid crystal and a non-liquid crystal property. It consists of a cured polymer material, and the ferroelectric liquid crystal in the ferroelectric liquid crystal layer and the cured product of the non-liquid crystalline polymer material are uniformly separated and mixed with each other to form an insulating film. The cured product of the non-liquid crystalline polymer material and the cured product of the non-liquid crystalline polymer material present in the ferroelectric liquid crystal layer are cured products of the non-liquid crystalline polymer material having adhesive properties to each other. And a liquid crystal optical element.

FIG. 1 is a partial cross-sectional view showing one embodiment of the liquid crystal optical element of the present invention. An insulating film is provided on two opposing substrates 1 and 1 'on which electrodes 2 and 2' are provided. 3 and 3 'are formed, and a ferroelectric liquid crystal layer 4 made of a cured product of a ferroelectric liquid crystal which is a mixture of a ferroelectric polymer liquid crystal and a ferroelectric low molecular liquid crystal and a non-liquid crystal polymer material is insulated. It is sandwiched between two substrates 1 and 1 'via films 3 and 3'. The insulating films 3 and 3 'are made of a cured product of a non-liquid crystalline polymer material, and the ferroelectric liquid crystal layer 4 is formed by curing a ferroelectric liquid crystal and a non-liquid crystalline polymer material which are uniformly separated from each other and mixed. It is composed of things. The insulating film may be provided on only one substrate, or may be provided on both substrates.

In the liquid crystal optical element of the present invention, a ferroelectric liquid crystal which is a mixture of a ferroelectric polymer liquid crystal and a ferroelectric low molecular liquid crystal, and a non-liquid crystal polymer material are cured in a ferroelectric liquid crystal layer. Since the ferroelectric liquid crystal layer is excellent in mechanical strength due to the mixture of the material and the ferroelectric liquid crystal layer, and even if the ferroelectric liquid crystal layer is deformed by strong pressing, conduction between the upper and lower electrodes is prevented by the presence of the insulating film. You. The insulating film functions not only as an insulating material but also as a reinforcing material, further improving the strength of the ferroelectric liquid crystal layer and the entire device. In addition, the cured product of the non-liquid crystalline polymer material mixed in the ferroelectric liquid crystal layer and the cured product of the non-liquid crystalline polymer material forming the insulating film are obtained by curing the same non-liquid crystalline polymer material. Therefore, the substrate and the ferroelectric liquid crystal layer are firmly adhered to each other via the insulating layer, thereby stabilizing the ferroelectric liquid crystal layer.

The amount of the cured non-liquid crystalline polymer material present in the ferroelectric liquid crystal layer is usually 1 to 30 parts by weight, preferably 1 to 20 parts by weight, per 100 parts by weight of the ferroelectric liquid crystal. It is desirable to do. When the amount of the cured product of the non-liquid crystalline polymer material is less than 1 part by weight, the function as a reinforcing material and an adhesive does not appear, and the strength of the ferroelectric liquid crystal layer may not be sufficiently improved. . If the amount exceeds 30 parts by weight, the contrast ratio of the liquid crystal optical element may decrease, and the orientation of the ferroelectric liquid crystal layer may decrease.

The thickness of the ferroelectric liquid crystal layer is usually 0.5 to 1
0 μm, preferably about 0.5 to 4 μm is suitable.

Each insulating film has a thickness of usually 0.01 to 5 μm.
m, preferably 0.02 to 2 μm, particularly preferably 0.1 to 0.2 μm.
When the insulating film is provided on both substrates, the thicknesses may be the same or different.

In the liquid crystal optical element of the present invention, a spacer may be further provided between the substrates. By arranging the spacer, the cell gap holding ability and the pressure resistance are further improved, and the ferroelectric liquid crystal layer is further stabilized.

The liquid crystal optical element of the present invention can be suitably manufactured by, for example, the manufacturing method of the present invention.

According to the manufacturing method of the present invention, a non-liquid crystalline polymer material is dissolved in a solvent on at least one of the two electrode-attached substrates, each of which has flexibility. A process of applying an aqueous solution, then evaporating the solvent and curing the non-liquid crystalline polymer material to form an insulating film, a ferroelectric liquid crystal comprising a mixture of a ferroelectric polymer liquid crystal and a ferroelectric low molecular liquid crystal And a non-liquid crystalline polymer material used to form the insulating film and a non-liquid crystalline polymer material having adhesive properties to each other, and a liquid crystal solution dissolved in a solvent is applied on the insulating film on at least one substrate. And then evaporating the solvent to form a ferroelectric liquid crystal layer in which the ferroelectric liquid crystal and the non-liquid crystal polymer material are uniformly separated from each other and mixed together, and the two substrates are ferroelectric. A liquid crystal layer is formed between these two substrates via an insulating film. Laminating as is sandwiched Te,
And a step of curing the non-liquid crystalline polymer material in the ferroelectric liquid crystal layer of the laminate.

In the present invention, since a flexible substrate is used as at least one of the substrates, even a large-area liquid crystal optical element can be easily and continuously mass-produced. It is also possible to prevent air bubbles from entering the cell.

As the flexible substrate used in the present invention, various substrates can be used, but usually, strength, heat resistance, transparency, etc. are considered from the viewpoints of productivity, insolubility, workability and the like. A substrate made of plastic having excellent durability and the like is preferably used. Specific examples of the flexible plastic include, for example, crystalline polymers such as uniaxially or biaxially stretched polyethylene terephthalate (PET), non-crystalline polymers such as polysulfone and polyethersulfone (PES), polyethylene, and polypropylene. Polyolefin, polycarbonate (PC), polyamide such as nylon and the like. Among them, polyethylene terephthalate (PET), polyether sulfone (PES), polycarbonate (PC) and the like are preferably used.

In the present invention, one of the substrates may be a substrate having no flexibility, and the material thereof is not particularly limited as long as it is used for a liquid crystal optical element. For example, a glass substrate or the like can be used. In order to manufacture a liquid crystal optical element having a curved screen or the like with high productivity, it is preferable that both substrates are made of a flexible material such as plastic.

The thickness of the substrate is usually 1 μm to 10 μm.
mm, preferably 10 μm to 1 mm.

In the present invention, the two substrates may be made of the same material or different materials. Usually, at least one of the substrates is optically transparent. It is used by providing an optically transparent or translucent electrode.

Specific examples of the transparent or translucent electrode include a tin oxide film called a NESA film, an indium oxide film mixed with tin oxide called an ITO film, an indium oxide film, and a deposited film of gold or titanium. Or other metal or alloy such as aluminum in the form of a thin film. The shape of these electrodes is not particularly limited,
It may be over the entire surface on a predetermined surface of the substrate,
It may be striped or any other desired shape.

The ferroelectric liquid crystal composed of a mixture of a ferroelectric polymer liquid crystal and a ferroelectric low-molecular liquid crystal used in the present invention may be any one as long as a mixture of a high-molecular liquid crystal and a low-molecular liquid crystal exhibits ferroelectricity. There is no particular limitation on the composition, but a mixture of a ferroelectric polymer liquid crystal and a ferroelectric low-molecular liquid crystal as shown below is preferably used, for example.

[0024]

Embedded image

In the present invention, the non-liquid crystalline polymer material used for forming the insulating film and reinforcing the ferroelectric liquid crystal layer has an insulating property and an adhesive property, and is used in a solvent used in manufacturing a liquid crystal optical element. There is no particular limitation as long as it is soluble, and any of a thermoplastic resin or a curable resin may be used.For example, polyimide, polyamide, polyester, cellulose, melamine resin, acrylic resin, epoxy resin, fluorinated epoxy resin, urethane resin, Examples include fluorinated urethane resins, fluorinated vinyl resins, silicones, mixtures of two or more thereof, and copolymers thereof. Among these, preferred non-liquid crystalline polymer materials from the viewpoint of easiness of film forming treatment include, for example, fluorine-containing vinyl resin, acrylic resin,
Epoxy resins, fluorinated epoxy resins, and fluorinated urethane resins. In particular, fluorine-containing vinyl resins such as fluoroethylene / divinyl ether copolymer, fluoroethylene / acrylic monomer copolymer, and fluoroethylene / vinyl ester copolymer, silicone, epoxy resin, and acrylic resin are preferably used. If necessary, a curing agent, a catalyst, a curing accelerator and the like may be added to these non-liquid crystalline polymer materials. These non-liquid crystalline polymer materials may be used alone or in combination of two or more.

In the insulating film and the ferroelectric liquid crystal layer of the liquid crystal optical element of the present invention, the non-liquid crystalline polymer material exists as a cured product. In the present specification, the curing of the non-liquid crystalline polymer material means that when the non-liquid crystalline polymer material is a thermoplastic resin, the molten thermoplastic resin is solidified by cooling, or by evaporation of the solvent. Means solidifying, non-liquid crystal polymer material is thermosetting resin,
In the case of a curable resin such as a crosslinkable resin, it means that the curable resin is crosslinked by heat, a curing agent, a catalyst, or the like to become insoluble and infusible.

In the present specification, the non-liquid crystalline polymer materials having adhesive properties to each other means those having affinity or adhesive property when cured. A preferred combination is the same kind of non-liquid crystalline polymer materials.

In the present invention, the cured product of the non-liquid crystalline polymer material is used as a structural material. Therefore, even if the compatibility of the non-liquid crystalline polymer material with the ferroelectric polymer liquid crystal is large,
It may be small or any.

When the spacer is arranged in the liquid crystal optical element of the present invention, the spacer is not particularly limited as long as it is usually provided in the liquid crystal optical element, but the material is silica or a plastic having solvent resistance and is spherical. Are suitable for a method of manufacturing a liquid crystal optical element by a continuous process, and are suitably used. As a plastic suitable for the spherical spacer used in the present invention, for example, divinylbenzene-based Dynospheres (manufactured by Nippon Synthetic Rubber Co., Ltd.) and the like can be mentioned. The particle size of the spherical spacer is determined by the desired film thickness of the ferroelectric liquid crystal layer and the film thickness of the insulating film, and is usually 1 to 10 μm.

The amount of the spherical spacer is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 1 part by weight, based on the cured product of the non-liquid crystalline polymer material forming the insulating film on one substrate.
0 parts by weight, particularly preferably 1 to 10 parts by weight. When the amount of the spherical spacer is less than 0.1 part by weight, the effect of the spherical spacer in maintaining the cell gap and improving the pressure resistance may be insufficient. When the amount exceeds 10 parts by weight, the contrast of the liquid crystal optical element may be reduced. There is a possibility that the ratio may decrease, and the orientation and the orientation retention of the ferroelectric liquid crystal layer may decrease.

The method for manufacturing a liquid crystal optical element of the present invention will be described below by taking as an example a case where an insulating film is provided on both of two flexible substrates and a spherical spacer is further provided.

First, two types of non-liquid crystalline polymer material solutions used for forming an insulating film are prepared. One non-liquid crystalline polymer material solution was prepared by uniformly dissolving a non-liquid crystalline polymer material in a solvent, and the other non-liquid crystalline polymer material solution was prepared as a non-liquid crystalline polymer material and a spherical spacer. Is uniformly dissolved and dispersed in a solvent to prepare a solution.

The solvent is not particularly limited as long as it does not dissolve the substrate but dissolves the non-liquid crystalline polymer material.
Usually, acetone, methyl ethyl ketone, toluene, xylene, dichloromethane, chloroform, tetrahydrofuran, ethyl acetate, a mixed solvent thereof or the like is suitably used. The concentration of the non-liquid crystalline polymer material is not particularly limited, and is appropriately selected according to a coating method and a desired film formation state such as a desired film thickness.

In dispersing the spherical spacer,
It is preferable to disperse the spherical spacer uniformly in the solution using ultrasonic waves or the like. The amount of the spherical spacer mixed into the non-liquid crystalline polymer material solution containing the spherical spacer,
The amount is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 10 parts by weight, particularly preferably 1 to 10 parts by weight based on 100 parts by weight of the non-liquid crystalline polymer material.

The liquid crystal solution used for forming the ferroelectric liquid crystal layer comprises a ferroelectric liquid crystal, a non-liquid crystal polymer material used for forming an insulating film, and a non-liquid crystal polymer material having adhesive properties to each other. The non-liquid crystalline polymer material is usually 1 to 30 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the ferroelectric liquid crystal.
It is prepared by uniformly dissolving or dispersing in a solvent in a ratio of parts by weight. Even when the spherical spacer is not provided, the ratio between the ferroelectric liquid crystal and the non-liquid crystalline polymer material is the same as described above.

A dichroic dye may be mixed in the ferroelectric liquid crystal layer in addition to the ferroelectric liquid crystal and the non-liquid crystalline polymer material. Examples of the dichroic dye include anthraquin, azo, diazo, and merocyanine dyes.

As the solvent used for preparing the liquid crystal solution, various solvents such as methylene chloride, chloroform, toluene, xylene, tetrahydrofuran, acetone, methyl ethyl ketone, and ethyl acetate can be used, and a mixed solvent thereof can also be used. it can. The concentration of the non-liquid crystalline polymer material is not particularly limited, and is appropriately selected according to a coating method and a desired film formation state such as a desired film thickness.
The amount of the solvent to be used is not particularly limited, and is appropriately selected depending on a coating method and a desired film formation state such as a desired film thickness.

Next, a non-liquid crystalline polymer material solution containing a spherical spacer is applied on the surface of one of the substrates to which the electrodes are attached, and after the solvent is evaporated, the non-liquid crystalline polymer material is cured. . The method of applying the non-liquid crystalline polymer material solution is not particularly limited. Specific examples include a method using a bar coater, a rod coating method, a slot coating method, a knife coating method, a direct gravure roll method, and a microgravure roll method. The method of curing the non-liquid crystalline polymer material depends on the material of the non-liquid crystalline polymer material, but is mainly by light irradiation or heating at room temperature or higher. When a spherical spacer is provided by this method, a non-liquid crystalline polymer material other than one solidified by evaporation of a solvent is used as the non-liquid crystalline polymer material used for forming the ferroelectric liquid crystal layer. In this manner, as shown in FIG. 2, the insulating film 3 made of a cured non-liquid crystalline polymer material is formed on the surface of the substrate 1 on which the electrodes 2 are provided. The spherical spacer 5 is firmly fixed on the surface of the substrate 1 on which the electrode 2 is provided by an insulating film 3 made of a cured material of a non-liquid crystalline polymer material.

A non-liquid crystalline polymer material solution containing no spherical spacer is applied to the surface of the other substrate on which the electrodes are provided, and after the solvent is evaporated, the non-liquid crystalline polymer material is cured. Thus, as shown in FIG. 3, an insulating film 3 'made of a cured product of a non-liquid crystalline polymer material is formed on the surface of the substrate 1' on which the electrodes 2 'are provided.

Next, a liquid crystal solution is applied on the insulating film 3 'on the substrate 1' on which the spherical spacers are not fixed, and then the solvent is evaporated, so that the ferroelectric liquid crystal and the non-liquid crystalline polymer material are separated. Form a ferroelectric liquid crystal layer which is uniformly separated from each other and mixed. As a method of applying the liquid crystal solution, the same method as the method of applying the non-liquid crystalline polymer material solution can be used. Thus, as shown in FIG. 4, the ferroelectric liquid crystal layer 4 is formed on the insulating film 3 'on the surface of the substrate 1' on which the electrodes 2 'are provided. At this stage, the non-liquid crystalline polymer material in the ferroelectric liquid crystal layer 4 has not been cured.

Next, the above substrates 1 and 1 'are laminated so that the ferroelectric liquid crystal layer 4 is sandwiched between these two substrates 1 and 1' via the insulating films 3 and 3 '. This lamination is suitably performed, for example, by a normal lamination method using a pressure roller or the like.

FIG. 5 shows the simplest example of a laminating method using this pressure roller. The substrate 1 provided with the insulating film 3 and the spherical spacer 5 on the surface provided with the electrode 2 and the substrate 1 'provided with the insulating film 3' and the ferroelectric liquid crystal layer 4 on the surface provided with the electrode 2 '. Then, the ferroelectric liquid crystal layer 4 is laminated between the pressure roller pair 6 so as to be sandwiched between the insulating films 3 and 3 '. By the pressing of the pressure roller pair 6, the spherical spacer 5 fixed to the substrate 1 is buried in the ferroelectric liquid crystal layer 4 and comes into contact with the insulating film 3 'on the substrate 1', whereby a laminate is formed. You.

Next, the non-liquid crystalline polymer material in the ferroelectric liquid crystal layer 4 of the laminate is cured by light irradiation, heating and the like.

FIG. 6 is a partial cross-sectional view of the liquid crystal optical element manufactured as described above.

The insulating films 3 and 3 'are respectively provided on the surface of the substrate 1 on which the electrodes 3 are provided and on the surface of the substrate 1' on which the electrodes 3 'are provided. The spherical spacer 5 exists in a state of being in contact with the surface of the substrate 1 on which the electrode 2 is provided and the insulating film 3 'on the substrate 1'.

In the case of a liquid crystal optical element in which an insulating film is not provided on one of the substrates 1 ', the spherical spacer 5 is provided on the surface of the substrate 1 on which the electrodes 2 are provided and on the surface of the substrate 1' on which the electrodes 2 'are provided. Exists in contact.

FIG. 7 is a partially enlarged view of the liquid crystal optical element of FIG. In the ferroelectric liquid crystal layer 4, a cured product 7 of a non-liquid crystalline polymer material is dispersed in a state of being separated from the ferroelectric liquid crystal,
It functions as a reinforcing material for the ferroelectric liquid crystal layer 4. Further, the spherical spacer 5 is firmly fixed on the surface of the substrate 1 on which the electrode 2 is provided by the insulating film 3, and is also formed by the cured product 7 of the non-liquid crystalline polymer material dispersed in the ferroelectric liquid crystal layer 4. Fixed. Further, the cured product of the non-liquid crystalline polymer material forming the insulating films 3 and 3 'and the cured product of the non-liquid crystalline polymer material in the ferroelectric liquid crystal layer 4 have a non-liquid crystalline high adhesive property with each other. Since it is a cured product of a molecular material, the insulating films 3 and 3 '
Adheres firmly to the ferroelectric liquid crystal layer 4 and stabilizes the ferroelectric liquid crystal layer 4 in the liquid crystal optical element.

The liquid crystal optical element of the present invention is used as an optical element by aligning the ferroelectric liquid crystal in the ferroelectric liquid crystal layer.
As the orientation method, any generally known method can be used. When the orientation by the orientation film is employed, the insulation film may be rubbed in one direction and used as an orientation layer, or various orientation films such as obliquely deposited silicon oxide on the insulation film may be used. It can also be used. When an alignment film is not used, a shearing method can be used. When two flexible substrates are used, the laminate is subjected to bending deformation before the non-liquid crystalline polymer material in the ferroelectric liquid crystal layer is cured, so that the ferroelectric liquid in the ferroelectric liquid crystal layer is hardened. It is also possible to use a method of orienting a liquid crystal. The orientation by bending deformation may be performed while applying an electric field between the electrodes. According to this method, a better orientation can be obtained.

According to the method of the present invention, a liquid crystal optical element excellent in external pressure and the like can be easily and continuously manufactured without a special step for installing a spacer material. In addition, by mixing the spherical spacer into the non-liquid crystalline polymer material solution for forming the insulating film, the spacer can be arranged by a simple method of applying the non-liquid crystalline polymer material solution to the substrate. Further enhancement of the element and improvement of the cell gap holding ability can be easily performed.

[0050]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Embodiment 1 1. As a solution (1) for forming an insulating film, Lumiflon LF200 (trade name, manufactured by Asahi Glass Co., Ltd.) having methyl ethyl ketone as a solvent and being soluble in an organic solvent.
A solution was prepared by dissolving 5% by weight of a mixture having a weight ratio of 5: 1 to an isocyanate-based curing agent. Further, as a solution (2) for forming an insulating film, a spherical silica spacer having a diameter of 2.4 μm was added to a solution prepared in the same manner as the solution (1) in an amount of 0.1 part by weight based on 100 parts by weight of the Lumiflon solution. To prepare a dispersed solution.

2. The solution (1) was applied on the electrode surface of a polyethersulfone substrate with an ITO transparent electrode by a microgravure coating method, and after the solvent was evaporated, the coating film was heated at a temperature of 120 ° C. for 20 minutes to remove Lumiflon. This was cured to form an insulating film having a thickness of 0.1 μm.
The shape of the electrode has a width of 1.
A simple stripe having a width of 17 mm and a gap of 0.1 mm was used.

3. A liquid crystal solution was applied on the insulating film formed in 2 by a microgravure coating method. As the ferroelectric liquid crystal, a liquid crystal composed of a ferroelectric polymer liquid crystal A and a ferroelectric low molecular liquid crystal B (weight ratio, A: B = 3: 7) having the following structural formula is used. For parts by weight, Lumiflon LF200 (trade name, Asahi Glass Co., Ltd.)
And a isocyanate-based curing agent in a weight ratio of 5 to 1 (hereinafter simply referred to as lumiflon) together with 5 parts by weight of the mixture were dissolved in methyl ethyl ketone to obtain a liquid crystal solution. The ratio of the total amount of ferroelectric liquid crystal and lumiflon in the liquid crystal solution was 30% by weight (that is, methyl ethyl ketone: 7).
0% by weight). After applying the liquid crystal solution, the solvent was evaporated by heating to form a ferroelectric liquid crystal layer having a thickness of 2.0 μm.

[0054]

Embedded image (Iso: isotropic phase, SmA: smectic A phase, SmC
^* : Chiral smectic C phase, Cry. : Crystalline state)

4. The solution (2) was applied on the electrode surface of the same type of substrate as used in 2 in the same manner as in 2, the solvent was evaporated and Lumiflon was cured, and a 0.1 μm thick insulating film and a spherical spacer were provided. A substrate was prepared.

5. The substrate provided with the insulating film and the ferroelectric liquid crystal layer obtained in 3 and the substrate provided with the insulating film and the spherical spacer obtained in 4 are sandwiched between pressure rolls by the method shown in FIG. Then, an optical liquid crystal element was produced.

6. The liquid crystal optical device obtained in 5 was subjected to bending deformation while applying a voltage of 40 V and 50 Hz between the upper and lower electrodes, thereby aligning the ferroelectric liquid crystal in the device. Next, the liquid crystal optical element is heated at 75 ° C. for 60 minutes,
Lumiflon in the ferroelectric liquid crystal layer was cured.

7. A 40 × 40 × 5 mm acrylic plate was placed on the aligned and cured liquid crystal optical element obtained in 6 above, and a load test was conducted by placing a 1 kg weight on the acrylic plate. Table 1 shows the results. In Table 1, a defective pixel is
It means a pixel in which the disorder of the alignment can be visually confirmed.

Embodiment 2 1. As a solution (1) for forming an insulating film, a solution in which 10% by weight of lumiflon was dissolved using methyl ethyl ketone as a solvent was prepared. In addition, as a solution (2) for forming an insulating film, a solution prepared in the same manner as the solution (1) had a diameter of 2.
A solution was prepared by dispersing a 4 μm spherical silica spacer in an amount of 0.1 part by weight based on 100 parts by weight of Lumiflon.

2. The solution (1) was applied on the electrode surface of the same substrate as used in Example 1-2 by a microgravure coating method, and after the solvent was evaporated, the solution (2) was heated at a temperature of 120 ° C.
Lumiflon was cured for 0 minutes to form an insulating film having a thickness of 0.1 μm.

3. A liquid crystal solution was applied on the insulating film formed in 2 by a microgravure coating method. The same ferroelectric liquid crystal as used in Example 1-3 was used, and this was dissolved in methyl ethyl ketone together with 1 part by weight of Lumiflon per 100 parts by weight of the ferroelectric liquid crystal.
A liquid crystal solution was obtained. The ratio of the total amount of ferroelectric liquid crystal and lumiflon in the liquid crystal solution was 30% by weight (that is, methyl ethyl ketone: 70% by weight). After applying the liquid crystal solution, the solvent was evaporated by heating to form a ferroelectric liquid crystal layer having a thickness of 2.0 μm.

4. The solution (2) was applied on the electrode surface of the same type of substrate as used in 2 in the same manner as in 2, the solvent was evaporated and Lumiflon was cured, and a 0.1 μm thick insulating film and a spherical spacer were provided. A substrate was prepared.

5. The substrate provided with the insulating film and the ferroelectric liquid crystal layer obtained in 3 and the substrate provided with the insulating film and the spherical spacer obtained in 4 are laminated in the same manner as in 5 of Example 1 to obtain an optical liquid crystal. An element was manufactured.

6. The same operation as in 6 of Example 1 was performed on the liquid crystal optical element obtained in 5 to align the ferroelectric liquid crystal and cure Lumiflon in the ferroelectric liquid crystal layer.

7. A load test similar to 7 of Example 1 was performed on the aligned and cured liquid crystal optical element obtained in 6. Table 1 shows the results.

Comparative Example 1 1. As a solution (1) for forming an insulating film, a solution in which 10% by weight of lumiflon was dissolved using methyl ethyl ketone as a solvent was prepared. In addition, as a solution (2) for forming an insulating film, a solution prepared in the same manner as the solution (1) had a diameter of 2.
A solution was prepared by dispersing a 4 μm spherical silica spacer in an amount of 0.1 part by weight based on 100 parts by weight of Lumiflon.

2. The solution (1) was applied on the electrode surface of the same substrate as used in Example 1-2 by a microgravure coating method, and after the solvent was evaporated, the solution (2) was heated at a temperature of 120 ° C.
Lumiflon was cured for 0 minutes to form an insulating film having a thickness of 0.1 μm.

3. A liquid crystal solution was applied on the insulating film formed in 2 by a microgravure coating method. The same ferroelectric liquid crystal as that used in Example 1-3 was used, and this was dissolved in methyl ethyl ketone without adding Lumiflon to obtain a liquid crystal solution. The ratio of the ferroelectric liquid crystal in the liquid crystal solution was 30% by weight (that is, methyl ethyl ketone: 70% by weight). After applying the liquid crystal solution, the solvent was evaporated by heating to form a ferroelectric liquid crystal layer having a thickness of 2.0 μm.

4. The solution (2) was applied on the electrode surface of the same type of substrate as used in 2 in the same manner as in 2, the solvent was evaporated and Lumiflon was cured, and a 0.1 μm thick insulating film and a spherical spacer were provided. A substrate was prepared.

5. The substrate provided with the insulating film and the ferroelectric liquid crystal layer obtained in 3 and the substrate provided with the insulating film and the spherical spacer obtained in 4 are laminated in the same manner as in 5 of Example 1 to obtain an optical liquid crystal. An element was manufactured.

6. The liquid crystal optical element obtained in 5 was subjected to the same alignment operation as in the alignment method of 6 in Example 1 to align the ferroelectric liquid crystal and cure Lumiflon in the ferroelectric liquid crystal layer.

7. A load test similar to 7 of Example 1 was performed on the aligned liquid crystal optical element obtained in 6. Table 1 shows the results.

[0073]

[Table 1]

As is clear from Table 1, Examples 1 and 2
In the liquid crystal optical element obtained in Comparative Example 1, the number of defective pixels is significantly reduced as compared with the liquid crystal optical element obtained in Comparative Example 1. In particular, the occurrence of defective pixels when the load test was performed for 9 days was about 5 to 6 times smaller than that of Comparative Example 1 in Examples 1 and 2, and excellent mechanical strength was maintained over a long period of time. I understand.

The liquid crystal optical element obtained in Example 1 was peeled off, and the surface of the substrate on which the spherical spacer was attached was observed with a microscope. The substrate had a structure as shown in FIG. Was found to have improved.

In the liquid crystal optical element of the present invention, a hardened material of a non-liquid crystalline polymer material as a reinforcing material is contained in a ferroelectric liquid crystal layer composed of a mixture of a ferroelectric polymer liquid crystal and a ferroelectric low molecular liquid crystal. It is dispersed in a state separated from the dielectric liquid crystal and contains not only low molecular liquid crystal but also high molecular liquid crystal as ferroelectric liquid crystal, and furthermore, an insulating film is provided between the substrate and the ferroelectric liquid crystal phase. Due to the provision, excellent mechanical strength is exhibited, and alignment defects and passage defects due to external pressure and the like are significantly reduced. In addition, the cured product of the non-liquid crystalline polymer material forming the insulating film and the cured product of the non-liquid crystalline polymer material in the ferroelectric liquid crystal layer are cured of the non-liquid crystalline polymer material having adhesive properties to each other. As a result, the insulating film and the ferroelectric liquid crystal layer adhered to the substrate are firmly adhered to each other, and have strong resistance to peeling. Even when the spherical spacer is mixed, the spherical spacer is firmly fixed by the cured material of the non-liquid crystal polymer material in the insulating layer and the ferroelectric liquid crystal layer, and exhibits excellent cell gap holding ability.

According to the method of manufacturing a liquid crystal optical element of the present invention, the liquid crystal optical element of the present invention is a large-area liquid crystal optical element without requiring a special step for installing a spacer material. Can also be manufactured easily and continuously. In addition, by mixing the spherical spacer into the non-liquid crystalline polymer material solution for forming the insulating film, the spacer can be arranged by a simple method of applying the non-liquid crystalline polymer material solution to the substrate. Further enhancement of the element and improvement of the cell gap holding ability can be easily performed.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing one embodiment of a liquid crystal optical element of the present invention.

FIG. 2 is a partial cross-sectional view showing a state where one substrate is provided with an insulating film and a spherical spacer in the method for manufacturing a liquid crystal optical element of the present invention.

FIG. 3 is a partial cross-sectional view showing a state where an insulating film is provided on the other substrate in the method for manufacturing a liquid crystal optical element of the present invention.

FIG. 4 is a partial cross-sectional view showing a state in which a ferroelectric liquid crystal film is further provided on a substrate provided with an insulating film in the method for manufacturing a liquid crystal optical element of the present invention.

FIG. 5 is a partial cross-sectional view showing a laminating step in the method for manufacturing a liquid crystal optical element of the present invention.

FIG. 6 is a partial cross-sectional view showing one embodiment of the liquid crystal optical element of the present invention.

7 is a partially enlarged view of the liquid crystal optical element shown in FIG.

FIG. 8 is a partial cross-sectional view showing the surface of one substrate when the liquid crystal optical element of the present invention is peeled off.

[Explanation of symbols]

 Reference Signs List 1 substrate 1 'substrate 2 electrode 2' electrode 3 insulating film 3 'insulating film 4 ferroelectric liquid crystal layer 5 spherical spacer 6 pressure roll 7 cured non-liquid crystalline polymer material

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02F 1/1333 610 G02F 1/1339 500

Claims (9)

(57) [Claims] In a liquid crystal optical element in which a ferroelectric liquid crystal layer is sandwiched between two substrates having electrodes, at least one of which has flexibility, a non-liquid crystal surface is formed on at least one of the substrates on which the electrodes are provided. It has an insulating film made of a cured polymer material, and the ferroelectric liquid crystal layer is made of a ferroelectric liquid crystal made of a mixture of a ferroelectric polymer liquid crystal and a ferroelectric low molecular liquid crystal and a non-liquid crystal polymer material. The ferroelectric liquid crystal in the ferroelectric liquid crystal layer and the cured material of the non-liquid crystalline polymer material are uniformly separated and mixed with each other in the ferroelectric liquid crystal layer to form an insulating film. Liquid crystal optics characterized in that the cured product of the molecular material and the cured product of the non-liquid crystalline polymer material present in the ferroelectric liquid crystal layer are cured products of a non-liquid crystalline polymer material having adhesive properties to each other. element. 2. A cured product of a non-liquid crystalline polymer material constituting an insulating film is polyimide, polyamide, polyester, cellulose, melamine resin, epoxy resin, fluorinated epoxy resin, urethane resin, fluorinated urethane resin, or fluorinated vinyl. The liquid crystal optical element according to claim 1, wherein the liquid crystal optical element is a cured product of a non-liquid crystalline polymer material selected from the group consisting of resin, silicone, a mixture of two or more of these, and a copolymer of two or more of these. 3. A cured product of a non-liquid crystalline polymer material is contained in the ferroelectric liquid crystal layer in an amount of 1 to 3 parts by weight based on 100 parts by weight of the ferroelectric liquid crystal.
The liquid crystal optical element according to claim 1, wherein the liquid crystal optical element is contained in an amount of 0 parts by weight. 4. A cured product of a non-liquid crystalline polymer material which forms an insulating film and has a spherical spacer made of silica or a solvent-resistant plastic having an insulating film on only one substrate. The liquid crystal optical element according to any one of claims 1 to 3, wherein the liquid crystal optical element is arranged in an amount of 0.1 to 10 parts by weight with respect to part by weight and in contact with the electrode-attached surfaces of the two opposing substrates. 5. An insulating film is provided on both substrates, and a spherical spacer made of silica or a solvent-resistant plastic is provided on one surface of the substrate on which the electrodes are provided and on the other substrate. It is arranged in contact with the film, and the amount of the spherical spacer is the amount of the non-liquid crystalline polymer material that forms the insulating film formed on the substrate on which the spherical spacer is in contact with the electrode-attached surface of the substrate. 0.1 parts by weight for 100 parts by weight of the cured product.
The liquid crystal optical element according to claim 1, wherein the amount is 1 to 10 parts by weight. 6. A solution in which a non-liquid crystalline polymer material is dissolved in a solvent is applied to at least one of the two substrates with electrodes, at least one of which has flexibility, on a surface on which the electrodes are attached, Next, a step of forming an insulating film by evaporating the solvent and curing the non-liquid crystalline polymer material, a ferroelectric liquid crystal composed of a mixture of ferroelectric polymer liquid crystal and ferroelectric low molecular liquid crystal, A liquid crystal solution obtained by dissolving the non-liquid crystalline polymer material used for the formation and the non-liquid crystalline polymer material having adhesiveness to each other in a solvent is applied on the insulating film on at least one substrate, and then the solvent is evaporated. Forming a ferroelectric liquid crystal layer in which the ferroelectric liquid crystal and the non-liquid crystalline polymer material are uniformly separated from each other and mixed together, and the two substrates are formed of an insulating film. Through the two substrates so that they are sandwiched between these two substrates. 2. The method for manufacturing a liquid crystal optical element according to claim 1, comprising a step of forming a layer and a step of curing a non-liquid crystalline polymer material in the ferroelectric liquid crystal layer of the laminate. 7. The non-liquid crystalline polymer material is polyimide, polyamide, polyester, cellulose, melamine resin, acrylic resin, epoxy resin, fluorinated epoxy resin, urethane resin, fluorinated urethane resin, fluorinated vinyl resin, silicone, 7. The method for producing a liquid crystal optical element according to claim 6, wherein the liquid crystal optical element is selected from the group consisting of a mixture of two or more of these and a copolymer of two or more of these. 8. The method according to claim 6, wherein the liquid crystal solution contains the non-liquid crystalline polymer material in an amount of 1 to 30 parts by weight based on 100 parts by weight of the ferroelectric liquid crystal. 9. A solution of a non-liquid crystalline polymer material to be coated on an electrode-attached surface of one of the substrates comprises a spherical spacer made of silica or a solvent-resistant plastic material. 9. The method for producing a liquid crystal optical element according to claim 6, wherein the content is 0.1 to 10 parts by weight based on 100 parts by weight.