KR102097811B1 - Preparation Method for Optical Device - Google Patents

Abstract

The present application relates to a method for manufacturing an optical device and an optical device. In the present application, a manufacturing method is provided for minimizing or eliminating dotting unevenness that may occur when an optical device is manufactured by a dotting process. Such a method of the present application may provide an alignment film with improved orientation by improving the dot staining even when a high temperature heat treatment is impossible due to a particularly large cell gap or a polymer substrate applied as a substrate.

Description

Manufacturing method for optical device {Preparation Method for Optical Device}

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

Optical devices capable of controlling light transmittance or color by disposing a light modulation layer between substrates are known. For example, Patent Document 1 discloses a so-called GH cell (Guest host cell) to which a mixture of a liquid crystal host and a dichroic dye guest is applied.

Various methods for manufacturing such an optical device are known. In one of them, the optical modulating material is doped on a substrate having an alignment layer formed on the surface, and the opposing substrate is compressed on the doped optical modulating material so that the optical modulating material is purged at intervals between the substrates. However, there is a method of filling the gap (hereinafter, referred to as a dotting process).

1 is a view exemplarily showing a process in which the above-described dotting process is performed. As shown in FIG. 1, the dotting process is performed by dotting the light modulating material 301 to an appropriate portion on the substrate 201A, and then applying pressure to the other substrate 201B with a roller 302 or the like to bond the dot to the light modulating material. It can be performed to spread evenly between the substrates. However, the process shown in FIG. 1 is an example of a dotting process, and the actual dotting process may be variously changed based on the method shown in FIG. 1.

This method can significantly improve productivity by reducing Turn Around Time (TAT) compared to a method of injecting a liquid crystal after first bonding an opposing substrate. However, the method is that when the crimping, spotting unevenness due to misalignment often occurs in a region where the light-modulating material is spread out from the dotted region.

The present application relates to a method for manufacturing an optical device and an optical device. One object of the present application is to provide a method for manufacturing a device having excellent performance without dot staining and an optical device manufactured in such a way even when an optical device is manufactured by applying a dotting process.

The present application relates to a method for manufacturing an optical device. The manufacturing method of the exemplary optical device of the present application relates to a manufacturing method of an optical device including a process of forming an alignment film on a substrate layer, wherein the alignment film is formed using an alignment film forming material including an alignment film forming material, The concentration of the alignment layer forming material in the alignment layer forming material is 2.5% by weight or more, and the formed alignment layer may have a polarity of 0.1 or less.

This application relates to optical devices. Exemplary optical devices of the present application include a first substrate; A second substrate facing the first substrate; And a light-modulating material present between the first and second substrates, the surface facing the second substrate of the first substrate and the surface facing the first substrate of the second substrate. A horizontal alignment layer is formed on, and at least one of the alignment layer formed on the first substrate and the alignment layer formed on the second substrate may have a polarity of 0.1 or less.

In the present application, a manufacturing method is provided for minimizing or eliminating dotting unevenness that may occur when an optical device is manufactured by a dotting process. Such a method of the present application may provide an alignment film with improved orientation by improving the dot staining even when a high temperature heat treatment is impossible due to a particularly large cell gap or a polymer substrate applied as a substrate.

1 is a diagram showing a process of an exemplary dotting process.
2 is an image observing the spotting stain of Examples 1 to 3 of the present application.
3 is an image observing the dot staining of Comparative Examples 1 to 6 of the present application.

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

The term optical device category can switch between two or more different optical states, for example, high transmittance and low transmittance states, high transmittance, medium transmittance and low transmittance states, and states in which different colors are implemented. All kinds of devices formed to be included may be included.

The manufacturing method may include a step of forming an alignment layer on the base layer. Such a process can be formed using, for example, an alignment film forming material containing an alignment film forming material.

In the above, as the substrate layer, any substrate layer used as a substrate in the configuration of a known optical device, such as a liquid crystal display (LCD), for example, 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 base layer, a glass base layer or the like can be exemplified, and as the organic base layer, various plastic films or the like can be exemplified. As a plastic film, a triacetyl cellulose (TAC) film; COP (cyclo olefin copolymer) films such as norbornene derivatives; Acrylic films such as PMMA (poly (methyl methacrylate); PC (polycarbonate) films; Polyolefin films such as PE (polyethylene) or PP (polypropylene); PVA (polyvinyl alcohol) films; DAC (diacetyl cellulose) films; Pac (Polyacrylate) Film; PES (poly ether sulfone) film; PEEK (polyetheretherketon) film; PPS (polyphenylsulfone) film, PEI (polyetherimide) film; PEN (polyethylenemaphthatlate) film; PET (polyethyleneterephtalate) film; PI (polyimide) film; PSF (polysulfone) Films or polyarylate (PAR) films may be exemplified, but are not limited thereto.

The manufacturing method of the present application can be particularly useful when an organic substrate layer, such as a plastic film, is used as the substrate layer. When a spotting stain or the like occurs, the stain is removed by treating the stained device or the like at a high temperature, for example, by treating the stain at a temperature higher than Tni of the liquid crystal compound, which is an example of a light-modulating material. Methods of removal are known. However, when the organic base layer is applied as a 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 the spotting stain from occurring without the high temperature treatment as described above, it is possible to form an alignment film having excellent physical properties even when an organic base layer is applied.

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

In the manufacturing method of the present application, an alignment film may be directly formed on the base layer, or may be formed on the other layer or component in a state where other layers or components are present on the base layer.

Examples of the other layers to configurations in the above are not particularly limited, and all known layers and configurations required for driving and configuring optical devices are all included. Examples of such a layer to structure include an electrode layer or a spacer.

In this application, an alignment layer is formed on the substrate layer in order to control the alignment of the liquid crystal compound. The type of the alignment film applied in the present application is not particularly limited, and a known alignment film can be used. For example, it satisfies suitable coating properties, solubility in solvents, heat resistance, chemical resistance, durability against orientation treatment such as rubbing, etc., and displays appropriate tilting properties, etc. as necessary, and manages impurity It is possible to apply all known alignment films satisfying physical properties such as an appropriate voltage holding ratio (VHR) and high contrast ratio. The alignment film may be, for example, a vertical or horizontal alignment film. As a vertical or horizontal alignment film, an alignment film having a vertical or horizontal alignment capability with respect to the liquid crystal compound of an adjacent liquid crystal layer can be selected and used without particular limitation. As such an alignment layer, for example, an alignment layer known to exhibit 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, can be used.

The alignment film may be produced by applying an alignment film forming material prepared by dispersing, diluting, and / or dissolving the alignment film forming material in an appropriate solvent as an alignment film forming material including an alignment film forming material.

As the type of the alignment layer forming material, any kind of material known to be capable of exhibiting an alignment capability such as a vertical or horizontal alignment capability to a liquid crystal can be used by appropriate treatment. Alignment film forming materials include polyimide compounds, poly (vinyl alcohol) compounds, poly (amic acid) compounds, polystyrene compounds, polyamide compounds, and polyoxyethylene (polyoxyethylene) compound, polynorbornene compound, phenylmaleimide copolymer compound, polyvinylcinamate compound, polyazobenzene compound, polyethyleneimide compound, polyethylene ( polyethylene) compounds, polystylene compounds, polyphenylenephthalamide compounds, polyester compounds, chloromethylated polyimide (CMPI) compounds, polyvinylcinnamate (PVCI) compounds and polymethyl methacrylate It may be one or more selected from the group consisting of compounds. In the present application, since it is required to adjust the polarity of the alignment layer to a predetermined range, as described later, it may be required to select a material that is advantageous for exhibiting the polarity of the range described below among the aforementioned known materials, but the polarity is Since it is also possible to control the concentration of the alignment layer forming material to be described later, basically, 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. The solvent that can be applied at this time is basically not particularly limited. For example, as a solvent, cycloalkanes such as cyclohexane or cycloalkanes having 3 to 12 carbon atoms or 3 to 8 carbon atoms, dimethyl sulfoxide (DMSO), tetrahydrofuran (THF), dimethylformamide (DMF), and NMethyl-pyrrolidone (NMP) , Chloroform (CHCl ₃ ), gamma-butyrolactone or ketone solvents such as cyclopentanone, alcohols such as 2-butoxyethanol or glycols such as ethylene glycol, or a mixture of two or more selected solvents Can be applied.

The concentration of the alignment layer forming material in the alignment layer forming material may be about 2.5% by weight or more. Through the application of such concentration, an alignment layer having excellent alignment ability can be formed without the occurrence of dotting stains after the dotting process. It is considered that the polarity of the alignment film to be described later changes mainly depending on the type of the alignment film forming material and the concentration of the alignment film forming material. For example, in the case of the polyimide-based alignment film-forming material described in Examples described later, the polarity tends to decrease as the concentration increases. Therefore, the concentration of the material may be adjusted according to the type of the alignment layer forming material selected, but even in this case, the limiting condition is that the concentration should be 2.5% by weight or more. The upper limit of the concentration is not particularly limited, and may be selected in consideration of fairness and the like. For example, the concentration of the alignment layer forming material is about 20 wt% or less, about 18 wt% or less, about 16 wt% or less, about 14 wt% or less, about 12 wt% or less, about 10 wt% or less, about 8 It may be less than or equal to about 6% by weight or less.

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

In the case where the heat treatment and / or drying process is performed in the above, the treatment temperature or time is not particularly limited and may be appropriately adjusted. For example, the process is performed at a temperature of about 50 ° C or higher, about 60 ° C or higher, about 70 ° C or higher, about 80 ° C or higher, about 90 ° C or higher, about 100 ° C or higher, about 110 ° C or higher, or about 120 ° C or higher Can be. In addition, the temperature is about 300 ° C or less, about 280 ° C or less, about 260 ° C or less, about 240 ° C or less, about 230 ° C or less, about 220 ° C or less, about 210 ° C or less, about 200 ° C or less, about 180 ° C or less, or It may be less than about 160 ℃.

The processing temperature of the process may also be selected in consideration of the state of the alignment layer forming material, the temperature, and the like, for example, an appropriate time may be selected within a range of about 1 minute to 2 hours.

In the manufacturing method of the present application, a step of performing an alignment treatment on the formed alignment layer (a layer of an alignment layer forming material) may be further 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 light alignment layer, the alignment treatment may be performed through an appropriate light irradiation treatment. The specific method of performing each treatment is not particularly limited, for example, the rubbing process, a method using a rubbing cloth such as cotton, rayon, or nylon can be applied, and the light irradiation process is a method of irradiating an appropriate linear polarization. Etc. can be applied.

In the present application, the alignment layer formed in the above manner may have a polarity of 0.1 or less. By controlling the polarity of the alignment film to 0.1 or less, it is possible to form an alignment film having excellent alignment ability without generating spotting stains or the like. In the above, the polarity of the alignment layer may be obtained by measuring the surface energy (γ ^surface ) of the alignment layer, in which case the surface energy is the dispersion force between the non-polar molecules (γ ^dispersion ) and the interaction force between the polar molecules (γ ^polar ). It is the sum (γ ^surface = f ^dispersion + p ^polar ), and the ratio of the interaction force between polar molecules in the surface energy (γ ^polar / γ ^surface ) may be defined as the polarity. This polarity can be measured in a known manner. In one example, the polarity may be obtained by first obtaining the above-mentioned surface energy, and the surface energy may be measured using a droplet shape analyzer (product made by KRUSS, DSA100). For example, after dropping a liquid having a known surface tension on the alignment film, for example, deionized water, the process of obtaining the contact angle is repeated 5 times, and the average value of the obtained 5 contact angle values is obtained. In addition, similarly, another liquid having a known surface tension, for example, diiodomethane is added dropwise to the alignment layer, and the process of obtaining the contact angle is repeated 5 times to obtain an average value of 5 contact angles. Subsequently, the surface energy can be obtained by substituting a numerical value (Strom value) for the surface tension of the solvent by the Owens-Wendt theory method using the obtained average value of the contact angle for deionized water and diiodmethane.

When the measured temperature among the properties mentioned in this specification affects the result, unless otherwise specified, the properties are measured at room temperature. The term room temperature is the temperature at which it is naturally heated and not reduced, and may be, for example, any temperature in the range of about 10 ° C to 30 ° C, or about 23 ° C or about 25 ° C. In the case where the measured pressure among the properties mentioned in this specification affects the result, unless otherwise specified, the properties are those measured at normal pressure. The term atmospheric pressure is a natural pressure that does not specifically raise or lower pressure, and generally means a pressure of about 1 atmosphere, such as atmospheric pressure. In the above, the polarity may be a polarity before performing a rubbing treatment or a polarity after being performed.

In other examples, the polarity may be about 0.095 or less, about 0.09 or less, about 0.085 or less, about 0.08 or less, about 0.075 or less, or about 0.07 or less. In addition, the polarity is about 0.001 or more, about 0.005 or more, about 0.01 or more, about 0.015 or more, about 0.02 or more, about 0.025 or more, about 0.03 or more, about 0.035 or more, or about 0.04 in other examples. The degree of abnormality may be about 0.045 or more, about 0.05 or more, or about 0.055 or more.

The polarity can be controlled by controlling the type and concentration of the alignment layer forming material. For example, as described above, in general, when the concentration of the alignment layer-forming material increases, the polarity tends to be lowered. Therefore, in consideration of the polarity of the alignment layer-forming material, the polarity is controlled by controlling the concentration in the above-mentioned range. You can.

The manufacturing method of the present application, the step of dotting a light modulating material containing a liquid crystal compound on the alignment layer formed as described above and the pressure in the state in which the opposing substrate is disposed opposite to the base layer having the alignment layer doped with the light modulating material The method may further include the step of allowing the dotted light modulating material to fill the gap between the base layer and the opposing substrate.

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

In addition, a material suitable for a liquid crystal compound to be applied is also selected and a suitable material is known as necessary without particular limitation.

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

In this case, the concentration of the alignment layer forming material in the alignment layer forming material described above is not particularly limited in the case of the counter substrate, but may be, for example, about 1.5% by weight or more. The concentration may be at least about 2% by weight in other examples. For example, the concentration of the alignment layer forming material is about 20 wt% or less, about 18 wt% or less, about 16 wt% or less, about 14 wt% or less, about 12 wt% or less, about 10 wt% or less, about 8 It may be less than or equal to about 6% by weight or less.

In addition, the polarity of the alignment layer of the opposing substrate formed as described above is not particularly limited in the case of the opposing substrate, but may be set to be about 0.1 or less in one example.

In other examples, the polarity may be about 0.095 or less, about 0.09 or less, about 0.085 or less, about 0.08 or less, or about 0.075 or less. In addition, the polarity is about 0.001 or more, about 0.005 or more, about 0.01 or more, about 0.015 or more, about 0.02 or more, about 0.025 or more, about 0.03 or more, about 0.035 or more, or about 0.04 in other examples. The degree of abnormality may be about 0.045 or more, or about 0.05 or more.

In the above process, the gap between the base layer and the counter substrate, that is, the so-called cell gap is also not particularly limited. However, in one example, the gap may be about 4 μm or more. In another example, 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, and the upper limit thereof is about 20 μm, about 18 μm, about 16 μm, about 14 μm, It may be about 12㎛ or about 10㎛. Typically, when the cell gap is small, for example, when it is less than about 4 μm, even when a dotting process is applied, the problem of dot staining is not significantly highlighted, but the problem is highlighted when the cell gap is large. However, there is a case where a high cell gap is required for the optical device as necessary, and when the method of the present application is applied, even in the manufacture of a device having a high cell gap, spotting unevenness can be minimized or suppressed.

If necessary, the light-modulating material may further include a dichroic dye. For example, the dichroic dye may be divided into two types, a molecule that absorbs more light in a specific direction than other directions, and a positive dichroic dye or p that is a dye that absorbs polarization in the long axis direction of the molecule. Type 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 centering on a wavelength causing maximum absorption. In addition, dyes used in guest host LCDs include chemical and optical stability, color and absorption spectrum width, dichroic ratio, color order, solubility in host, degree of non-ionization, and extinction. ) It can be evaluated by characteristics such as coefficient and purity and high specific resistance. It is assumed that the dichroic dye is a positive dye unless otherwise specified.

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

As the dichroic dye, for example, a known dye known to have properties that can be aligned according to the alignment state of the liquid crystal can be selected and used. As a dichroic dye, a 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 can be appropriately selected in consideration of the purpose of the present application. For example, the dichroic dye may have a dichroic ratio of 5 or more to 20 or less. The term "dichroic ratio" in the present specification 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. Can be. Anisotropic dyes may have the dichroic ratio at least in part or at any wavelength within the wavelength range of the visible region, for example within the 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 facing the first substrate; And a light modulating material present between the first and second substrates. At least one of the first and second substrates may be formed in the above-described manner. For example, a horizontal alignment film is formed on a surface of the first substrate opposite to the second substrate and a surface of the second substrate opposite to the first substrate, and an alignment film formed on the first substrate and the agent 2 At least one of the alignment layers formed on the substrate may have a polarity of 0.1 or less.

That is, in this case, the first substrate is a substrate manufactured in the above-described manner. In this case, the specific type of the substrate layer included in the substrate, and the specific range of the type and polarity of the alignment layer may be in accordance with 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 act as a guest-host type light modulating material. That is, in the guest-host type light modulating material, dichroic dyes are arranged together according to the arrangement of the liquid crystal compound to absorb the light parallel to the alignment direction of the dye and transmit the vertical light to exhibit anisotropic light absorption effect. . In addition, the content of the anisotropic dye in 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 wt% or more to 10 wt% or less.

Further, the cell gap of the optical device, that is, the gap between the first and second substrates is not particularly limited. However, in one example, the gap may be about 4 μm or more. In another example, 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, and the upper limit thereof is about 20 μm, about 18 μm, about 16 μm, about 14 μm, It may be about 12㎛ or about 10㎛.

Hereinafter, the present application will be described in detail 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 polarity

The polarity of the alignment layer is first obtained by obtaining the surface energy (γ ^surface ), which is the sum (γ ^surface = γ ^dispersion + γ ^polar ), which is the sum of the dispersion forces (γ ^dispersion ) between non-polar molecules and the interaction forces (γ ^polar ) between polar molecules at normal temperature and pressure. The surface energy was obtained from the ratio of the interaction force between polar molecules (γ ^polar / γ ^surface ).

The surface energy was measured using a droplet shape analyzer (Drop Shape Analyzer, manufactured by KRUSS, DSA100). After adding deionized water having a known surface tension to the alignment film, the process of obtaining the contact angle was repeated 5 times, and the average value of the obtained 5 contact angle values was obtained. Further, similarly, the average value of the five contact angles obtained after repeating the process of obtaining the contact angle 5 times by dropping diiodomethane having a known surface tension into the alignment layer was obtained. Subsequently, the surface energy was obtained by substituting a numerical value (Strom value) for the surface tension of the solvent by the Owens-Wendt theory method using the obtained average value of the contact angle for deionized water and diiodine methane, and the polarity was measured accordingly. .

Example 1.

Fabrication of the upper substrate

The upper substrate was produced by forming an alignment layer on a COP (cycloolefin polymer) film having an indium tin oxide (ITO) electrode layer formed on one surface. The alignment layer is formed using an alignment layer forming material in which polyimide-based alignment layer forming material (Nissan, SE-7492) is dispersed in cyclopentanone and ethylene glycol at a concentration of about 2% by weight. Did. The alignment layer forming material was coated so that the final alignment layer thickness was about 200 nm by a bar coating method. Subsequently, a baking and imidizing process was performed in an oven at about 130 ° C. for about 20 minutes. Then, the baking and imidized layers were rubbed in a determined direction to form an alignment layer. The polarity of the alignment layer formed in the above manner was about 0.072.

Fabrication of the lower substrate

The lower substrate was produced in the same manner as the upper substrate. However, in the case of the lower substrate, a ball spacer having a size in the range of 6 to 8 μm was applied according to a known method. The alignment layer is a polyimide-based alignment layer-forming material (Nissan, SE-7492) as a solvent, using an alignment layer-forming material dispersed in cyclopentanone and ethylene glycol (Ethylene glycol) at a concentration of about 2.5% by weight. It was formed, and the final alignment layer thickness was about 250 nm. The polarity of the alignment film thus formed was about 0.064.

Fabrication of optical devices

An adhesive applied to the production of a liquid crystal cell is coated on an end of the upper substrate manufactured as described above, and a light modulating material (Merck's MAT-16-969 (ne: 1.5463, no: 1.4757, in an appropriate position on the lower substrate) ε∥: 7.4, ε⊥: 3.2, TNI: 85 ° C, Δn: 0.0706, Δ ε: 4.2) Dotting the light by dotting the upper and lower substrates, followed by bonding the upper and lower substrates. An optical device was prepared by spreading the material evenly between the two substrates. In the process, the cell gap between the upper and lower substrates was maintained at about 8 μm.

Example 2

Each of the upper and lower substrates was prepared in the same manner as in Example 1, but the alignment layer of the upper substrate was formed of a polyimide-based alignment layer-forming material (Nissan, SE-7492) as a solvent, and cyclopentanone ( Cyclopentanone) and ethylene glycol (Ethylene glycol) were used to form an alignment film-forming material dispersed at a concentration of about 2% by weight to form a final alignment film having a thickness of about 200 nm, and the alignment film of the lower substrate was used as an alignment film forming material. Is, a polyimide-based alignment film forming material (Nissan, SE-7492) as a solvent, cyclopentanone (cyclopentanone) and ethylene glycol (Ethylene glycol) is used in an alignment film forming material dispersed in a concentration of about 4% by weight Thus, the final alignment layer was formed to have a thickness of about 400 nm. The polarity of the alignment film on the formed upper substrate was about 0.072, and the polarity of the alignment film on the lower substrate was about 0.065.

Optical devices were manufactured in the same manner as in Example 1 using the upper and lower substrates manufactured as described above.

Example 3

Each of the upper and lower substrates was prepared in the same manner as in Example 1, but the alignment layer of the upper substrate was formed of a polyimide-based alignment layer-forming material (Nissan, SE-7492) as a solvent, and cyclopentanone ( Cyclopentanone) and ethylene glycol (Ethylene glycol) were used to form an alignment film-forming material dispersed at a concentration of about 6% by weight to form a final alignment film having a thickness of about 600 nm, and the alignment film of the lower substrate was an alignment film-forming material. Is, a polyimide-based alignment film forming material (Nissan, SE-7492) as a solvent, cyclopentanone (cyclopentanone) and ethylene glycol (Ethylene glycol) is used in an alignment film forming material dispersed in a concentration of about 4% by weight Thus, the final alignment layer was formed to have a thickness of about 400 nm. The polarity of the alignment film on the formed upper substrate was about 0.056, and the polarity of the alignment film on the lower substrate was about 0.065.

Optical devices were manufactured in the same manner as in Example 1 using the upper and lower substrates manufactured as described above.

Comparative Example 1

Each of the upper and lower substrates was prepared in the same manner as in Example 1, but the alignment layer of the upper substrate was formed of a polyimide-based alignment layer-forming material (Nissan, SE-7492) as a solvent, and cyclopentanone ( Cyclopentanone) and ethylene glycol (Ethylene glycol) were used to form an alignment film-forming material dispersed at a concentration of about 2% by weight to form a final alignment film having a thickness of about 200 nm, and the alignment film of the lower substrate was used as an alignment film forming material. The polyimide-based alignment film-forming material (Nissan, SE-7492) is used as an alignment film-forming material in a concentration of about 0.5% by weight in cyclopentanone and ethylene glycol. Thus, the final alignment layer was formed to have a thickness of about 50 nm. The polarity of the alignment film on the formed upper substrate was about 0.072, and the polarity of the alignment film on the lower substrate was about 0.186.

Optical devices were manufactured in the same manner as in Example 1 using the upper and lower substrates manufactured as described above.

Comparative Example 2

Each of the upper and lower substrates was prepared in the same manner as in Example 1, but the alignment layer of the upper substrate was formed of a polyimide-based alignment layer-forming material (Nissan, SE-7492) as a solvent, and cyclopentanone ( Cyclopentanone) and ethylene glycol (Ethylene glycol) were used to form an alignment film-forming material dispersed at a concentration of about 2% by weight to form a final alignment film having a thickness of about 200 nm, and the alignment film of the lower substrate was used as an alignment film forming material. For the polyimide-based alignment film-forming material (Nissan, SE-7492) as a solvent, cyclopentanone and ethylene glycol (Ethylene glycol) are used in an alignment film-forming material dispersed in a concentration of about 1.5% by weight. Thus, the final alignment layer was formed to have a thickness of about 150 nm. The polarity of the alignment film on the formed upper substrate was about 0.072, and the polarity of the alignment film on the lower substrate was about 0.160.

Optical devices were manufactured in the same manner as in Example 1 using the upper and lower substrates manufactured as described above.

Comparative Example 3

Each of the upper and lower substrates was prepared in the same manner as in Example 1, but the alignment layer of the upper substrate was formed of a polyimide-based alignment layer-forming material (Nissan, SE-7492) as a solvent, and cyclopentanone ( Cyclopentanone) and ethylene glycol (Ethylene glycol) were used to form an alignment film-forming material dispersed at a concentration of about 2% by weight to form a final alignment film having a thickness of about 200 nm, and the alignment film of the lower substrate was used as an alignment film forming material. For the polyimide-based alignment film-forming material (Nissan, SE-7492) as a solvent, an alignment film-forming material dispersed in a concentration of about 2% by weight in cyclopentanone and ethylene glycol (Ethylene glycol) is used. Thus, the final alignment layer was formed to have a thickness of about 200 nm. The polarity of the alignment film on the formed upper substrate was about 0.072, and the polarity of the alignment film on the lower substrate was about 0.128.

Optical devices were manufactured in the same manner as in Example 1 using the upper and lower substrates manufactured as described above.

Comparative Example 4

Each of the upper and lower substrates was prepared in the same manner as in Example 1, but the alignment layer of the upper substrate was formed of a polyimide-based alignment layer-forming material (Nissan, SE-7492) as a solvent, and cyclopentanone ( Cyclopentanone) and ethylene glycol (Ethylene glycol) were used to form an alignment film-forming material dispersed at a concentration of about 6% by weight to form a final alignment film having a thickness of about 600 nm, and the alignment film of the lower substrate was an alignment film-forming material. The polyimide-based alignment film-forming material (Nissan, SE-7492) is used as an alignment film-forming material in a concentration of about 0.5% by weight in cyclopentanone and ethylene glycol. Thus, the final alignment layer was formed to have a thickness of about 50 nm. The polarity of the alignment film on the formed upper substrate was about 0.056, and the polarity of the alignment film on the lower substrate was about 0.186.

Optical devices were manufactured in the same manner as in Example 1 using the upper and lower substrates manufactured as described above.

Comparative Example 5

Each of the upper and lower substrates was prepared in the same manner as in Example 1, but the alignment layer of the upper substrate was formed of a polyimide-based alignment layer-forming material (Nissan, SE-7492) as a solvent, and cyclopentanone ( Cyclopentanone) and ethylene glycol (Ethylene glycol) were used to form an alignment film-forming material dispersed at a concentration of about 6% by weight to form a final alignment film having a thickness of about 600 nm, and the alignment film of the lower substrate was an alignment film-forming material. Is, a polyimide-based alignment film-forming material (Nissan, SE-7492) as a solvent in cyclopentanone (cyclopentanone) and ethylene glycol (Ethylene glycol) in an concentration of about 1% by weight of the alignment film forming material is used Thus, the final alignment layer was formed to have a thickness of about 100 nm. The polarity of the alignment film on the formed upper substrate was about 0.056, and the polarity of the alignment film on the lower substrate was about 0.166.

Optical devices were manufactured in the same manner as in Example 1 using the upper and lower substrates manufactured as described above.

Comparative Example 6

Each of the upper and lower substrates was prepared in the same manner as in Example 1, but the alignment layer of the upper substrate was formed of a polyimide-based alignment layer-forming material (Nissan, SE-7492) as a solvent, and cyclopentanone ( Cyclopentanone) and ethylene glycol (Ethylene glycol) were used to form an alignment film-forming material dispersed at a concentration of about 6% by weight to form a final alignment film having a thickness of about 600 nm, and the alignment film of the lower substrate was an alignment film-forming material. For the polyimide-based alignment film-forming material (Nissan, SE-7492) as a solvent, an alignment film-forming material dispersed in a concentration of about 2% by weight in cyclopentanone and ethylene glycol (Ethylene glycol) is used. Thus, the final alignment layer was formed to have a thickness of about 200 nm. The polarity of the alignment film on the formed upper substrate was about 0.056, and the polarity of the alignment film on the lower substrate was about 0.128.

Optical devices were manufactured in the same manner as in Example 1 using the upper and lower substrates manufactured as described above.

Test example

In the examples and comparative examples, dot staining on the substrate / optical device prepared respectively was confirmed. This dot staining was confirmed by placing the manufactured optical device between the upper and lower polarizing plates arranged so that the absorption axis forms about 60 degrees and then photographing the case where the most stain is observed while rotating the optical device 360 degrees.

Attached FIG. 1 is a result of confirming the presence or absence of dot staining for Examples 1 to 3, and FIG. 2 is a result of confirming the presence or absence of dot staining for Comparative Examples 1 to 6.

1 and 2, in the case of the comparative example, the dot staining was confirmed, but in the example, it was confirmed that the stain was not confirmed.

In the Examples and Comparative Examples of the present application, the results of fabricating the optical device by dotting the light modulating material only on the lower substrate are shown, but when the optical device was fabricated by dotting the light modulating material on both the upper substrate and the lower substrate, The same results as in Examples 1 to 3 and Comparative Examples 1 to 6 were confirmed.

201A, 201B: Substrate
301: light modulating material
302: roller

Claims (16)

A method for manufacturing an optical device comprising a step of forming an alignment film on a base layer,
The alignment layer is a horizontal alignment layer, the alignment layer is formed using an alignment layer forming material containing an alignment layer forming material, the concentration of the alignment layer forming material in the alignment layer forming material is 2.5% by weight to 20% by weight or less, and the formed alignment layer Polarity of 0.1 or less,
The polarity of the alignment layer is obtained by measuring the surface energy (γ ^surface ) of the alignment layer, and the surface energy (γ ^surface ) is the sum of the dispersion force between non-polar molecules (γ ^dispersion ) and the interaction force between polar molecules (γ ^polar ). And the polarity of the alignment layer is defined as a ratio of the interaction force between polar molecules in the surface energy of the alignment layer (γ ^polar / γ ^surface ). The method of claim 1, wherein the base layer is a plastic film. The method according to claim 1, wherein an electrode layer is present on the substrate layer, and an alignment film is formed on the electrode layer. The method according to claim 1, wherein a spacer is present on the substrate layer, and an alignment film is formed on the spacer. delete The method of claim 1, wherein the alignment layer-forming material comprises a rubbing alignment layer-forming material. 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 polystyrene compound, a polyamide ) Compound, polyoxyethylene compound, polynorbornene compound, phenylmaleimide copolymer compound, polyvinylcinamate compound, polyazobenzene compound, polyethyleneimide ( polyethyleneimide) compounds, polyethylene compounds, polystylene compounds, polyphenylenephthalamide compounds, polyester compounds, chloromethylated polyimide (CMPI) compounds, polyvinylcinnamate (PVCI) compounds and polymethyl meta Preparation of at least one selected from the group consisting of polymethyl methacrylate compounds Law. The method according to claim 1, wherein the alignment film forming material further comprises a solvent. The manufacturing method according to claim 1, wherein the alignment film forming step includes a step of forming a layer of an alignment film forming material on the substrate layer and heat-treating the layer. The manufacturing method according to claim 1, further comprising a step of rubbing the formed alignment layer. The method of claim 1, further comprising: dotting a light modulating material comprising a liquid crystal compound on the formed alignment layer; And compressing the opposing substrate in a state in which the light modulating material is disposed opposite to the base layer having a dot-oriented alignment layer so that the dot-moded light modulating material fills the gap between the base layer and the opposing substrate. Manufacturing method. The manufacturing method according to claim 11, wherein a gap between the base layer and the counter substrate is 4 µm or more to 20 µm or less. A first substrate; A second substrate facing the first substrate; And a light modulating material present between the first and second substrates,
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,
At least one of the alignment layer formed on the first substrate and the alignment layer formed on the second substrate has a polarity of 0.1 or less,
The polarity of the alignment layer is obtained by measuring the surface energy (γ ^surface ) of the alignment layer, and the surface energy (γ ^surface ) is the sum of the dispersion force between non-polar molecules (γ ^dispersion ) and the interaction force between polar molecules (γ ^polar ). And the polarity of the alignment layer is defined as a ratio of the interaction force between polar molecules in the surface energy of the alignment layer (γ ^polar / γ ^surface ). 14. The optical device of claim 13, wherein the first and second substrates are plastic films. The optical device according to claim 13, wherein the light modulating material comprises a liquid crystal compound. 14. The optical device according to claim 13, wherein a space between the first and second substrates is 4 m to 20 m.

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