KR102159503B1 - Preparation Method for Optical Device - Google Patents

Abstract

The present application relates to a method of manufacturing an optical device and an optical device. In the present application, a manufacturing method capable of minimizing or eliminating doting spots that may occur when an optical device is manufactured by a doting process is provided. The method of the present application may improve the doting stain to provide an alignment layer having improved orientation even when the method of the present application has a large cell gap or a polymer substrate is applied as a substrate and thus high temperature heat treatment is impossible.

Description

Optical device manufacturing method TECHNICAL FIELD

The present application relates to a method of manufacturing an optical device and an optical device.

An optical device capable of adjusting light transmittance, color, etc. by disposing a light modulation layer between substrates is known. For example, in Patent Document 1, a so-called GH cell (Guest host cell) to which a mixture of a liquid crystal host and a dichroic dye guest is applied is known.

Various methods of manufacturing optical devices are known. In one of the methods, the optical modulation material is dotting on the substrate on which the alignment layer is formed on the surface, and the opposing substrate is pressed onto the doted optical modulation material, so that the light modulation material spreads in the gaps between the substrates. There is a method of filling the gap (also referred to as vacuum assembly LC (VALC) or one drop filling (ODF)) (hereinafter, it may be referred to as a doting process).

1 is a diagram illustrating a process of performing the doting process as described above. As shown in FIG. 1, the doting process is performed to spread the doted light modulating material evenly between the substrates by doting the light modulating material 301 on an appropriate portion of the substrate 201A and then bonding another substrate 201B. I can. However, the process shown in FIG. 1 is an example of the doting process, and the actual doting process may be variously changed based on the method shown in FIG. 1.

In this method, compared to other methods, only the required amount of liquid crystal can be used, so that the consumption amount of liquid crystal can be reduced, and even in the case of a large area, the productivity can be greatly improved by reducing TAT (Turn Around Time). However, in the above method, doting spots due to misalignment often occur in regions where the light modulating material is dotted and spread out during the compression.

The present application relates to a method of manufacturing an optical device and an optical device. One object of the present application is to provide a method of manufacturing a device having excellent performance without doting spots even when an optical device is manufactured by applying a doting process and an optical device manufactured in such a manner.

The present application relates to a method of manufacturing an optical device, and in an example, to a method of manufacturing an optical device by applying a doting process.

In the scope of the term optical device, it is possible to switch between two or more different optical states, e.g., high transmittance and low transmittance states, high transmittance, medium transmittance and low transmittance states, states in which different colors are implemented, etc. All types of devices formed to be configured may be included.

The manufacturing method may include forming an alignment layer on the substrate layer. Such a process can be formed using, for example, an alignment layer forming material including an alignment layer forming material.

In the manufacturing method of the present application, any substrate layer used as a substrate in the construction of a known optical device such as, for example, a liquid crystal display (LCD), may be applied without particular limitation. For example, the base layer may be an inorganic base layer or an organic base layer. As the inorganic substrate layer, a glass substrate layer and the like may be exemplified, and as the organic substrate layer, various plastic films may be exemplified. As a plastic film, a triacetyl cellulose (TAC) film; Cycloolefin copolymer (COP) films such as norbornene derivatives; Acrylic film such as PMMA (poly(methyl methacrylate)); PC (polycarbonate) film; Polyolefin film such as PE (polyethylene) or PP (polypropylene); PVA (polyvinyl alcohol) film; DAC (diacetyl cellulose) film; Pac (Polyacrylate) Film; PES (polyether sulfone) film; PEEK (polyetheretherketon) film; PPS (polyphenylsulfone) film, PEI (polyetherimide) film; PEN (polyethylenemaphthatlate) film; PET (polyethyleneterephtalate) film; PI (polyimide) film; PSF (polysulfone) A film or a polyarylate (PAR) film may be exemplified, but is not limited thereto.

The manufacturing method of the present application may be particularly useful when an organic substrate layer, for example, a plastic film is used as the substrate layer. A method of removing the spot by treating the device or the like in which the spot has occurred in the case of occurrence of doting spots, for example, by treating the spot at a temperature equal to or higher than Tni of a liquid crystal compound which is an example of a light modulating material. How to remove is known. However, when the organic base layer is applied as the substrate, the heat resistance of the organic base layer is poor, and it is difficult to perform a high-temperature heat treatment process. However, by the method described in the present specification, since it is possible to prevent doting stains from occurring even without the high-temperature treatment as described above, an alignment layer having excellent physical properties can be formed even when an organic substrate layer is applied.

In the present application, the thickness of the substrate layer is not particularly limited, and an appropriate range may be selected according to the use.

In the manufacturing method of the present application, the alignment layer may be formed directly on the base layer, or may be formed on the other layer or configuration while another layer or configuration is present on the base layer.

Examples of other layers or configurations in the above are not particularly limited, and all of the known layers or configurations required for driving and configuring an optical device are included. Examples of such layers or structures include electrode layers, spacers, and the like.

In the present application, an alignment layer is formed on the base layer in order to adjust the alignment state of the liquid crystal compound. The type of alignment layer applied in the present application is not particularly limited, and a known alignment layer may be used. For example, it satisfies appropriate coating properties, solubility in solvents, heat resistance, chemical resistance, and durability against orientation treatment such as rubbing, and shows appropriate tilting properties as needed, and impurity management All known alignment layers satisfying physical properties such as an appropriate voltage holding ratio (VHR) and a high contrast ratio may be applied. The alignment layer may be, for example, a vertical or horizontal alignment layer. As the vertical or horizontal alignment layer, any alignment layer having vertical or horizontal alignment capability with respect to the liquid crystal compound of the adjacent liquid crystal layer may be selected and used without particular limitation. As such an alignment layer, for example, an alignment layer known to be capable of exhibiting alignment characteristics by a non-contact method such as irradiation of linearly polarized light including a contact alignment layer or a photo alignment layer compound, such as a rubbing alignment layer, may be used.

The alignment layer is an alignment layer forming material containing an alignment layer forming material, for example, an alignment layer forming material prepared by dispersing, diluting and/or dissolving the alignment layer forming material in an appropriate solvent, that is, an alignment layer comprising an alignment layer forming material and a solvent It can be manufactured by applying a forming material.

As for the kind of the alignment layer forming material, all kinds of materials known to be capable of exhibiting alignment ability such as vertical or horizontal alignment ability with respect to liquid crystal by appropriate treatment may be used. Such materials include polyimide compounds, poly(vinyl alcohol) compounds, poly(amic acid) compounds, polystylene compounds, polyamide compounds, and polyoxy compounds. A material known to exhibit orientation ability by rubbing orientation, such as an ethylene (polyoxyethylene) compound, or a polyimide compound, a polyamic acid compound, a polynorbornene compound, a phenylmaleimide copolymer ( phenylmaleimide copolymer) compound, polyvinylcinamate compound, polyazobenzene compound, polyethyleneimide compound, polyvinylalcohol compound, polyimide compound, polyethylene compound, poly Light irradiation such as polystylene compound, polyphenylenephthalamide compound, polyester compound, chloromethylated polyimide (CMPI) compound, polyvinylcinnamate (PVC) compound, and polymethyl methacrylate compound, etc. A material known to be capable of exhibiting orientation capability may be exemplified. In the present application, since it is required to adjust the surface energy of the alignment layer in a predetermined range as described later, it may be required to select a material advantageous to exhibit surface energy in the range to be described later from among the known materials mentioned above. Since the surface energy is mainly controlled by the thickness of the alignment layer, the boiling point of the solvent, the heat treatment temperature, etc., the alignment layer forming material used in the present application is not particularly limited.

The alignment layer forming material may be prepared by diluting, dispersing, and/or dissolving the alignment layer forming material as described above in a solvent. In this case, it is advantageous to apply a solvent having a boiling point of 160°C or less as a solvent. It was confirmed that when a solvent having a boiling point exceeding 160°C is used as the solvent, the possibility of occurrence of doting stains is high. The boiling point may be about 100°C or more, 110°C or more, 120°C or more, or 125°C or more in other examples.

For example, as a solvent, a cycloalkane having 3 to 12 or 3 to 8 carbon atoms such as cyclohexane, dimethylformamide (DMF), chloroform (CHCl3), cyclohexanon, or cyclopentanone C 1 to C 12 or C 3 to C 8 ketone, C 1 to C 12 or C 1 to C 8 alcohol such as 2-butoxyethanol or butanol, or C 1 to C 12 or C 1 to C 8 such as ethylene glycol or butylene glycol Any one selected from the glycols or a solvent satisfying the above-described boiling point among the solvents selected from the above may be applied. If the above-described boiling point is satisfied as a whole, a mixture of two or more of the above-mentioned solvents may be used, or any one of the solvents may be used alone.

In the alignment layer forming material, the concentration of the alignment layer forming material may be in the range of about 0.1% to 10% by weight. Through the application of such a concentration, it is possible to form an alignment layer having excellent alignment performance without generating dot spots after the doting process.

In the present application, the alignment layer is formed by using the alignment layer forming material as described above, and in this case, a method of forming the alignment layer is not particularly limited. For example, the alignment layer forming process may include a process of forming a layer of an alignment layer forming material on a base layer and performing a known treatment such as an alignment treatment on the formed layer. In addition, when the layer of the alignment layer forming material is formed by coating or the like, and the time until firing is not constant for each substrate, or if it is not fired immediately after application, a pretreatment process such as a drying process may be performed. For example, processes such as drying and/or heat treatment may be performed using an appropriate dryer, oven, or hot plate.

The alignment layer forming process of the present application may further include a process of heat-treating the coated alignment layer-forming material, and in this case, the heat treatment may be performed at a temperature of about 115°C or less. The present inventors have confirmed that when the heat treatment temperature exceeds 115° C., doting stains are easily induced. The heat treatment process may be performed at a temperature of about 50°C or more, about 60°C or more, about 70°C or more, about 80°C or more, about 90°C or more, or about 95°C or more.

The heat treatment process may be performed within a range of, for example, about 1 minute to 2 hours. In another example, the heat treatment time is about 110 minutes or less, about 100 minutes or less, about 90 minutes or less, about 80 minutes or less, about 70 minutes or less, about 60 minutes or less, about 50 minutes or less, about 40 minutes or less, about 30 Or less, about 20 minutes or less, or about 15 minutes or less, or in other examples about 2 minutes or more, about 3 minutes or more, about 4 minutes or more, about 5 minutes or more, about 6 minutes or more, about 7 minutes or more, about It can be performed for at least 8 minutes or at least about 9 minutes.

In the process of forming the alignment layer as described above, the alignment layer may be formed to have a thickness of at least about 50 nm or more. If the thickness of the alignment layer is less than 50 nm, doting stains may be easily induced. The thickness of the alignment layer is not particularly limited as long as it is more than the above range, but in other examples, about 1,000 nm or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, or It may be 200 nm or less.

In the present application, the alignment layer formed in the same manner as described above may have a surface energy of about 41 mN/m or less. In another example, the surface energy is about 30 mN/m or more, 31 mN/m or more, 32 mN/m or more, 33 mN/m or more, 34 mN/m or more, 35 mN/m or more, 36 mN/m or more, 37 It may be mN/m or more, 38 mN/m or more, or 39 mN/m or more. Within this range of surface energy, it is possible to manufacture an excellent optical device without doting irregularities, and the surface energy can be controlled through the boiling point of the solvent described above, the thickness of the alignment layer, and the heat treatment temperature.

In the case where the measurement temperature affects the result among the physical properties mentioned in the present specification, the physical properties are those measured at room temperature unless otherwise stated. The term room temperature is a natural temperature that is not heated or reduced, and may be, for example, any temperature within the range of about 10°C to 30°C, or about 23°C or about 25°C. In the case where the measured pressure affects the result among the physical properties mentioned in the present specification, the physical properties are those measured at normal pressure unless otherwise stated. The term atmospheric pressure is a natural pressure that is not specifically raised or lowered, and generally refers to a pressure of about 1 atmosphere, such as atmospheric pressure.

In the above, the surface energy may be the surface energy before or after the rubbing treatment is performed.

In the manufacturing method of the present application, the step of performing an alignment treatment on the formed alignment layer (a layer of an alignment layer forming material) may be additionally performed. In this case, the orientation treatment can be performed in a known manner. For example, in the case of a rubbing alignment layer, an appropriate rubbing treatment may be performed, or in the case of a photo-alignment layer, the alignment treatment may be performed through an appropriate light irradiation treatment. The specific method of performing each of the above treatments is not particularly limited, for example, the rubbing process may be a method using a rubbing cloth made of cotton, rayon, nylon, etc., and the light irradiation process irradiates appropriate linearly polarized light. Method, etc. can be applied.

In the manufacturing method of the present application, the step of doting a light modulating material including a liquid crystal compound on the alignment layer formed as described above, and applying pressure in a state in which the opposing substrate faces the substrate layer having the alignment layer dotd with the light modulation material. By adding the doted light modulating material, the step of filling the gap between the base layer and the opposite substrate may be further included.

The above process may be performed, for example, according to a general doting process, and the specific process is not particularly limited.

In addition, a material such as a liquid crystal compound to be applied is not particularly limited, and a known suitable material is selected as needed.

In addition, the type of the counter substrate disposed to face the base layer is not particularly limited, and a known substrate may be applied. For example, the substrate may also include a base layer and an alignment layer formed on one surface thereof, and may include other configurations such as an electrode layer if necessary. A method of forming an alignment layer formed on the substrate layer of the counter substrate is not particularly limited, and a known method may be followed. In one example, the method of forming the alignment layer on the base layer of the opposite substrate may follow the above-described alignment layer forming method.

In the above process, the gap between the base layer and the counter substrate, that is, a so-called cell gap, is not particularly limited. However, in one example, the interval may be about 4 μm or more. The interval may be about 5 μm or more, about 6 μm or more, about 7 μm or more, or about 8 μm or more in another example, and the upper limit thereof is about 20 μm, about 18 μm, about 16 μm, about 14 μm, It may be about 12 μm or about 10 μm. In general, when the cell gap is small, for example, if it is less than about 4 μm, the problem of doting spots is not greatly emphasized even when the doting process is applied, but the above problem is highlighted when the cell gap is increased. However, there are cases where a high cell gap is required for the optical device as needed. If the method of the present application is applied, doting irregularities can be minimized or suppressed even in manufacturing a device having a high cell gap.

If necessary, the light modulation material may further include a dichroic dye. For example, the dichroic dye can be classified into two types. A dye that absorbs polarization in the long axis direction of the molecule as a molecule that absorbs more light in a specific direction than in other directions is a positive dichroic dye or p A dye absorbing light in a vertical direction may mean a negative dichroic dye or an n-type dye. In general, such a dye may have an absorption spectrum in a narrow region around a wavelength that causes maximum absorption. In addition, the dyes used in guest host LCD display are chemical and optical stability, color and absorption spectrum width, dichroic ratio, order of pigment, solubility in host, degree of nonionization, quenching ( extinction) coefficient, purity, and high specific resistance. Unless otherwise specified, the dichroic dye is assumed to be a positive dye.

In the present specification, the term ``dye'' may refer to a material capable of intensively absorbing and/or modifying light in at least a part or the entire range in a visible light region, for example, 400 nm to 700 nm wavelength range, The term "dichroic dye" may mean a material capable of dichroic absorption of light in at least a part or the entire range of the visible light region.

As the dichroic dye, for example, a known dye known to have a property that can be aligned according to the alignment state of the liquid crystal may be selected and used. As a dichroic dye, black dye can be used, for example. Such dyes are known as, for example, azo dyes or anthraquinone dyes, but are not limited thereto.

The dichroic ratio of the dichroic dye may be appropriately selected in consideration of the purpose of the present application. For example, the dichroic dye may have a dichroic ratio of 5 to 20 or less. In the present specification, the term "dicolor ratio" means, for example, in the case of a p-type dye, a value obtained by dividing the absorption of polarized light parallel to the long axis direction of the dye by the absorption of polarized light parallel to the direction perpendicular to the long axis direction. I can. The anisotropic dye may have the dichroic ratio in at least some wavelengths or at any one wavelength within a wavelength range of a visible light region, for example, within a wavelength range of about 380 nm to 700 nm or about 400 nm to 700 nm.

The present application also relates to an optical device, for example an optical device manufactured by the above manufacturing method. Such an optical device includes a first substrate; A second substrate disposed opposite to the first substrate; And a light modulating material present between the first and second substrates. In the above, at least one of the first and second substrates may be formed in the manner described above. For example, a horizontal alignment layer is formed on a surface of the first substrate facing the second substrate and a surface of the second substrate facing the first substrate, and the alignment layer formed on the first substrate and the second substrate 2 At least one of the alignment layers formed on the substrate may have a surface energy of 41 mN/m or less.

That is, in this case, the first substrate is a substrate manufactured in the manner described above. In this case, the specific type of the substrate layer included in the substrate, the type of the alignment layer, and the specific range of the surface energy may follow the above-described range.

The light modulating material may include a liquid crystal compound and a dichroic dye. When the light modulating material includes both a liquid crystal compound and a dichroic dye, the light modulating material may function as a guest-host type light modulating material. That is, in the guest-host type light modulation material, dichroic dyes are arranged together according to the arrangement of liquid crystal compounds, so that light parallel to the alignment direction of the dye is absorbed and light perpendicular to the dye is transmitted, thereby exhibiting an anisotropic light absorption effect. . In addition, the content of the anisotropic dye of the light modulating material may be appropriately selected in consideration of the purpose of the present application. For example, the content of the anisotropic dye in the light modulating material may be 0.1% by weight or more to 10% by weight or less.

Further, there is no particular limitation on the cell gap of the optical device, that is, the gap between the first and second substrates. However, in one example, the interval may be about 4 μm or more. The interval may be about 5 μm or more, about 6 μm or more, about 7 μm or more, or about 8 μm or more in another example, and the upper limit thereof is about 20 μm, about 18 μm, about 16 μm, about 14 μm, It may be about 12 μm or about 10 μm.

In the present application, a manufacturing method capable of minimizing or eliminating doting spots that may occur when an optical device is manufactured by a doting process is provided. The method of the present application may improve the doting stain to provide an alignment layer having improved orientation even when the method of the present application has a large cell gap or a polymer substrate is applied as a substrate and thus high temperature heat treatment is impossible.

1 is a diagram illustrating a process of performing an exemplary doting process.
2 to 11 are results of evaluating the occurrence of doting spots in Examples or Comparative Examples.

Hereinafter, the present application will be specifically described through examples according to the present application and comparative examples not according to the present application, but the scope of the present application is not limited by the examples presented below.

1. Measurement of surface energy

The surface energy of the alignment layer was measured using a drop shape analyzer (Drop Shape Analyzer, manufactured by KRUSS, DSA100). After dropping deionized water with known surface tension on the alignment layer, the process of obtaining the contact angle was repeated five times, and the average value of the obtained five contact angle values was obtained. In the same way, the average value of the five contact angles obtained after repeating the process of obtaining the contact angle by dropping MI (Diiodomethane), which has a known surface tension, onto the alignment layer was repeated five times. Subsequently, the surface energy was calculated by substituting a value (Strom value) regarding the surface tension of the solvent by the Owens-Wendt-Rabel-Kaelble method using the obtained average value of the contact angle for deionized water and diiodomethane.

2. Confirmation of doting stains

Dotting stains were confirmed in the following manner. After applying a voltage to the optical device manufactured in Example or Comparative Example to horizontally align the liquid crystal of the light modulating material, the linear polarizer was positioned perpendicular to the optical axis of the horizontally aligned liquid crystal, and the presence or absence of doting spots was checked.

Example 1.

A first substrate was fabricated by forming an alignment layer on a PC film (polycarbonate polymer) film on which an ITO (Indium Tin Oxide) electrode layer is formed on one side. Ball spacers were present on the PC film to maintain a cell gap of about 12 μm with the ITO electrode. The alignment layer was prepared by mixing a polyimide-based alignment layer forming material (Nissan Corp., SE-5661) and cyclopentanone (boiling point: about 131°C), and the proportion of the alignment layer forming material is about 0.7% by weight. I did.

The alignment layer forming material was coated so that the final alignment layer thickness was about 50 nm by a bar coating method. Subsequently, an alignment layer having a thickness of about 50 nm was formed by holding it in an oven at about 100° C. for about 10 minutes to perform a baking and imidizing process, followed by rubbing to form an alignment layer. The surface energy of the alignment layer formed in the above manner was about 40.6 mN/m after rubbing.

The second substrate was manufactured in the same manner as described above, but a PC film without spacers was applied when the second substrate was manufactured.

The end of the first substrate prepared as described above is coated with an adhesive that is usually applied to the production of a liquid crystal cell, and a light modulating material (HNG730200 of HCCH (ne: 1.551, no: 1.476, ε ∥: 9.6, ε) at an appropriate position. ⊥: 9.6, TNI: 100°C, Δn: 0.075, △ ε: -5.7) Dotting a mixture of liquid crystal and anisotropic dye (BASF, X12) and then bonding the second substrate, thereby dotting ( An optical device was manufactured by allowing the dotting) of the light-modulating material to spread evenly between the two substrates.

FIG. 2 is a result of observing the existence of doting spots with respect to the optical device formed in the same manner as described above, and no doting spots were observed as shown in FIG. 2.

Example 2

Each of the first and second substrates was prepared in the same manner as in Example 1, but the thickness of the alignment layer was about 100 nm, and an optical device was manufactured using the prepared substrate in the same manner. The surface energy of the alignment layer of the prepared substrate was about 39.5 mN/m when evaluated in the same manner as in Example 1.

3 is a result of observing the existence of doting spots with respect to the optical device formed in the same manner as described above, and no doting spots were observed as shown in FIG. 3.

Example 3

Each of the first and second substrates was prepared in the same manner as in Example 1, but as a solvent, cyclohexanone having a boiling point of about 155.6°C was used, and the thickness of the alignment layer was about 100 nm to prepare a substrate, An optical device was manufactured using the prepared substrate. The surface energy of the alignment layer of the prepared substrate was about 40.4 mN/m when evaluated in the same manner as in Example 1.

4 is a result of observing the existence of doting spots for the optical device formed in the same manner as described above, and no doting spots were observed as shown in FIG. 4.

Example 4

Each of the first and second substrates was prepared in the same manner as in Example 1, but the thickness of the alignment layer was about 100 nm, and the heat treatment temperature was changed to about 110°C to prepare a substrate, and using the prepared substrate. The optical device was fabricated. The surface energy of the alignment layer of the prepared substrate was about 40.6 mN/m when evaluated in the same manner as in Example 1.

5 is a result of observing the existence of doting spots with respect to the optical device formed in the same manner as described above, and no doting spots were observed as shown in FIG. 5.

Comparative Example 1

Each of the first and second substrates was prepared in the same manner as in Example 1, but the substrate was fabricated so that the thickness of the alignment layer was about 30 nm, and an optical device was fabricated using the prepared substrate. The surface energy of the alignment layer of the prepared substrate was about 42.8 mN/m when evaluated in the same manner as in Example 1.

6 is a result of observing the existence of doting spots with respect to the optical device formed in the same manner as described above, and the doting spots were severely observed as shown in FIG. 6.

Comparative Example 2

Each of the first and second substrates was prepared in the same manner as in Example 1, but the substrate was prepared so that the thickness of the alignment layer was about 40 nm, and an optical device was manufactured using the prepared substrate. The surface energy of the alignment layer of the prepared substrate was about 41.9 mN/m when evaluated in the same manner as in Example 1.

7 is a result of observing the existence of doting spots for the optical device formed in the same manner as described above, and as shown in FIG. 7, the doting spots were severely observed.

Comparative Example 3

Each of the first and second substrates was prepared in the same manner as in Example 1, but gamma butyrolactone having a boiling point of about 204°C was used as a solvent when preparing the alignment layer forming material, and the thickness of the alignment layer was about 100 nm. Thus, a substrate was prepared, and an optical device was manufactured using the prepared substrate. The surface energy of the alignment layer of the prepared substrate was about 41.9 mN/m when evaluated in the same manner as in Example 1.

FIG. 8 is a result of observing the existence of doting spots for the optical device formed in the same manner as described above, and as shown in FIG. 8, the doting spots were observed severely.

Comparative Example 4

Each of the first and second substrates was prepared in the same manner as in Example 1, but a solvent (DMAc (Dimethylacetamide)) having a boiling point of about 165° C. was used, and the thickness of the alignment layer was about 100 nm. , An optical device was manufactured using the prepared substrate. The surface energy of the alignment layer of the prepared substrate was about 41.2 mN/m when evaluated in the same manner as in Example 1.

9 is a result of observing the existence of doting spots for the optical device formed in the same manner as described above, and as shown in FIG. 9, the doting spots were observed severely.

Comparative Example 5

Each of the first and second substrates was prepared in the same manner as in Example 1, but the heat treatment temperature was about 130°C, and the thickness of the alignment layer was about 100 nm to prepare the substrate, and the prepared substrate was used for optical The device was fabricated. The surface energy of the alignment layer of the prepared substrate was about 41.9 mN/m when evaluated in the same manner as in Example 1.

FIG. 10 is a result of observing the existence of doting spots with respect to the optical device formed in the same manner as described above, and as shown in FIG. 10, the doting spots were severely observed.

Comparative Example 6

Each of the first and second substrates was prepared in the same manner as in Example 1, but the heat treatment temperature was about 120°C and the thickness of the alignment layer was about 100 nm to prepare the substrate, and the prepared substrate was used for optical The device was fabricated. The surface energy of the alignment layer of the prepared substrate was about 41.4 mN/m when evaluated in the same manner as in Example 1.

FIG. 11 is a result of observing the existence of doting spots with respect to the optical device formed in the same manner as described above, and as shown in FIG. 11, the doting spots were severely observed.

Claims (14)

As a method for manufacturing an optical device comprising a step of forming an alignment film on a base layer,
In the alignment layer forming process, an alignment layer forming material containing an alignment layer forming material and a solvent having a boiling point of 100° C. or more and 160° C. or less is coated to form an alignment layer having a thickness of 50 nm or more and 1,000 nm or less on the substrate layer, and 60° C. or more. And treating the coated alignment layer forming material at a temperature of to 115° C. or less, and rubbing the coated alignment layer forming material,
Doting a light modulating material including a liquid crystal compound on the formed alignment layer; And
Comprising the step of compressing the opposite substrate in a state in which the light modulating material is disposed opposite to the base layer having the doted alignment layer so that the doted light modulating material fills the gap between the base layer and the opposite substrate,
The alignment layer forming material is a material exhibiting alignment ability by rubbing orientation,
In the alignment layer forming material, the concentration of the alignment layer forming material is 0.1% to 10% by weight. The method of claim 1, wherein the base layer is a plastic film. The manufacturing method according to claim 1, wherein an electrode layer is present on the base layer, and an alignment layer is formed on the electrode layer. The manufacturing method of claim 1, wherein a spacer is present on the base layer, and an alignment layer is formed on the spacer. delete The method according to claim 1, wherein the alignment layer is a vertical alignment layer. delete The method of claim 1, wherein the alignment layer-forming material is a polyimide compound, a poly(vinyl alcohol) compound, a poly(amic acid) compound, a polystylene compound, a polyamide ) Compound, polyoxyethylene compound, polynorbornene compound, phenylmaleimide copolymer compound, polyvinylcinamate compound, polyazobenzene compound, polyethyleneimide ) Compound, polyethylene compound, polyphenylenephthalamide compound, polyester compound, CMPI (chloromethylated polyimide) compound, PVCI (polyvinylcinnamate) compound and polymethyl methacrylate compound A manufacturing method selected from the group consisting of. The method of claim 1, wherein the solvent is a mixed solvent or a single solvent selected from the group consisting of cycloalkane, DMF (dimethylformamide), chloroform (CHCl ₃ ), ketone, alcohol, and glycol to satisfy the boiling point. Way. delete The manufacturing method according to claim 1, wherein the surface energy is 30 mN/m or more and 41 mN/m or less. delete The method of claim 1, wherein the light modulating material further comprises a dichroic dye. The manufacturing method according to claim 1, wherein the distance between the base layer and the counter substrate is 4 µm or more and 20 µm or less.

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