JP2017181829A5 - - Google Patents

Description

[Louvre rod structure]
The plurality of louver rod structures 2 in the anisotropic light diffusion layer 1 of the present invention shown in FIG. 1 are characterized in that the cross-sectional shape perpendicular to the column axis direction has a substantially rounded rectangle.
Specifically, as shown in FIG. 2, the substantially rounded rectangle has a shape in which both ends of two substantially parallel lines having a parallel line width L are connected by a substantially arc. A long diameter line width Y of the substantially major axis line the maximum width of the substantially square RoundRectangle, parallel line width L can be confirmed by observing the anisotropic light-diffusing layer (anisotropic optical film) by an optical microscope.
In addition, as shown in FIG. 2, S, which is a substantially rounded rectangular width in a direction perpendicular to the long-diameter line width Y of the substantially rounded rectangle, is hereinafter referred to as a short-diameter line width.
The shape of the substantially rounded rectangular shape only needs to satisfy the regulations and formulas described later, and the linear shape or curved shape of the outer peripheral portion of the substantially rounded rectangular shape is another shape, for example, a wavy shape or an inclined shape, Each shape may be mixed.

(Relationship between Y and S)
In the present invention, since the cross-sectional shape orthogonal to the column axis direction of the plurality of louver rod structures is a substantially rounded rectangle, the relationship between the long diameter line width Y and the short diameter line width S is S <Y Need to be. In addition, the long diameter line width Y is preferably 0.5 μm to 50.0 μm , more preferably 1.0 μm to 10.0 μm , and even more preferably 1.0 μm. ˜5.0 μm. If it is less than 0.5 μm, the uncured resin composition layer of the anisotropic light diffusing layer cannot be faithfully irradiated with the photomask pattern, which may be easily affected by the optical proximity effect, and may exceed 50.0 μm. In such a case, glare due to light interference may easily occur.

That is, according to this method, a sample is disposed between the light source 4 and the detector 5, and the incident light angle from the light source 4 to the sample is rotated while rotating the sample around the rotation axis P of the sample. The linear transmitted light amount and the linear transmittance { Linear transmittance = (Linear transmitted light amount of the detector when there is a sample / Linear transmitted light amount of the detector when there is no sample) × 100} are measured by the detector 5. An optical profile is obtained from the obtained data, and the maximum linear transmittance and the minimum linear transmittance are obtained from this optical profile. In addition, when the linearly transmitted light amount and the linear transmittance are measured for each incident light angle so that the axis orthogonal to the AA line coincides with the rotation axis P shown in FIG. 3, the incident light is incident as shown in FIG. The linear transmitted light amount near zero is shown regardless of the light angle.

Although depending on the material forming the anisotropic light diffusion layer, the angle at which the plurality of louver rod structures diffuse light strongly depends on the column axis direction of the louver rod structure, that is, the inclination of the diffusion center axis, the louver rod structure This is when the difference between the inclination of the incident light and the traveling direction is in the range of approximately ± 10 °.
Further, when the louver rod structure is bent and extended in the column axis direction, a region where light is strongly diffused can be further expanded. This is because bending causes the louver rod structure to have a plurality of angular ranges in the column axis direction in which light is strongly diffused.
If multiple having the bending added, a region for diffusing light strongly, it is possible to form continuously in the column direction, while maintaining the intensity of light substantially constant, the more the light diffusion and The light collecting property can be improved.

The angle (bending angle) when the column axis direction of the louver rod structure is bent is preferably 10 ° to 40 ° in order to obtain a sufficient region for diffusing light strongly.
Further, when the bending angle is 15 ° to 25 °, the region where light is strongly diffused can be further expanded, which is more preferable.

Further, when the column axis direction of the louver rod structure has a plurality of inclinations, each inclination may be within a range of ± 70 ° when the normal direction to the plane of the anisotropic light diffusion layer is 0 °. Is preferred. The number of the plurality of slope is not limited, it is preferred to be between 2-5. This is because as the number of inclinations increases, the thickness of the anisotropic light diffusion layer increases in order to form the inclination, and the productivity decreases.

[Other layers]
It is good also as an anisotropic optical film which provided the other layer in one surface of the anisotropic light-diffusion layer. Examples of other layers include an adhesive layer, a polarizing layer, a light diffusion layer, a low reflection layer, an antifouling layer, an antistatic layer, an ultraviolet ray and near infrared (NIR) absorption layer, a neon cut layer, and an electromagnetic wave shielding layer. be able to.
Moreover, you may laminate | stack another layer sequentially. Further, other layers may be laminated on both surfaces of the anisotropic light diffusion layer. The other layer laminated on both surfaces may be a layer having the same function or a layer having another function.

In addition, the said cation polymeric compound may be used for each single-piece | unit, and multiple may be used in mixture.
Furthermore, a photocurable compound is not limited to the above. In addition, in order to cause a sufficient difference in refractive index, fluorine atoms (F) may be introduced into the photocurable compound in order to reduce the refractive index, and in order to increase the refractive index, sulfur atoms may be introduced. (S), bromine atoms (Br), and various metal atoms may be introduced. Further, as disclosed in Japanese Patent No. 4423040, acrylic particles are formed on the surface of ultrafine particles made of a metal oxide having a high refractive index such as titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), tin oxide (SnOx). It is also effective to add functional ultrafine particles into which a photopolymerizable functional group such as a group, a methacryl group, or an epoxy group is introduced to the photocurable compound.

[Photoinitiator]
Photoinitiators that can polymerize radically polymerizable compounds include benzophenone, benzyl, Michler's ketone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2- Diethoxyacetophenone, benzyldimethyl ketal, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2 -Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1 -One, bis (cyclo Ntajieniru) - bis [2,6-difluoro-3- (pyrr-1-yl) phenyl] titanium, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) - butanone -1,2,4 , 6-trimethylbenzoyldiphenylphosphine oxide and the like. These compounds may be used alone or in combination.

In this invention, the said photoinitiator is 0.01 weight part- 10 weight part with respect to 100 weight part of photocurable compounds, More preferably, 0.1 weight part- 7 weight part, More preferably, it is 0. it is preferable to be .1 to 5 parts by weight approximately formulation. This is because if less than 0.01 parts by weight, the photocurability is reduced, and if more than 10 parts by weight is blended, in addition to the adverse effect that only the surface is cured and the internal curability is reduced, coloring, This is because the louver rod structure formation is inhibited. These photoinitiators are usually used by directly dissolving powder in a photocurable compound, but if solubility is poor, a photoinitiator dissolved in a very small amount of solvent in advance at a high concentration is used. It can also be used. Such a solvent is more preferably photocurable, and specific examples thereof include propylene carbonate and γ-butyrolactone. It is also possible to add various known dyes and sensitizers to improve photocurability. Further, in the case of a photocurable compound that can be cured by heat, a thermosetting initiator capable of curing the photocurable compound by heating can be used in combination with the photoinitiator. In this case, polymerization and curing of the photocurable compound can be further promoted by heating after photocuring.

≪Process≫
Next, the manufacturing method (process) of the anisotropic optical film of this invention is demonstrated using FIGS. By sequentially performing the following steps, the cross-sectional shape having a plurality of louver rod structures and a matrix region and orthogonal to the column axis direction of the louver rod structures has both ends of two substantially parallel lines. An anisotropic optical film having a substantially rounded rectangular shape connected by a substantially arc can be obtained.
(1) A coating process in which a photocurable resin composition is coated on a substrate to provide a coating film (uncured resin composition layer) (2) A photomask is laminated on the uncured resin composition layer , Photomask lamination process (3) Parallel light acquisition process to obtain parallel light from light source (4) Photomask surface on uncured resin composition layer is irradiated with parallel light to polymerize and cure uncured resin composition layer Curing process
(5) Other layer laminating process for laminating other layers on the anisotropic light diffusing layer according to applications (optional)

<Photomask lamination process>
In order to form the cross-sectional shape orthogonal to the column axis direction of the plurality of louver rod structures of the anisotropic light diffusion layer in the anisotropic optical film of the present invention on the uncured resin composition layer, A step of laminating a photomask can be provided.
As the photomask, a substrate in which a desired substantially rounded rectangle is patterned according to a photomask manufacturing procedure can be used.
A specific photomask manufacturing procedure is as follows. First, a chromium film for forming a light shielding film that blocks ultraviolet rays is formed on the entire surface of a glass substrate to be a photomask. Thereafter, an electron beam resist (photosensitive material) is applied and baked, and then exposed, developed, and rinsed by an electron beam drawing apparatus to pattern the electron beam resist on the chromium film. Thereafter, an unnecessary chromium film is dissolved by etching, a hole through which ultraviolet rays are transmitted is formed, and then the resist is removed with a chemical solution, thereby completing a photomask.
Many substrates used for photomasks have a drawing pattern formed on glass or synthetic quartz using chromium as a light-shielding film as described above, but they are drawn on a transparent polymer film called an emulsion mask. It may be. In that case, it is preferable to form a light-shielding film with blackened metal silver instead of chromium.
The pattern size of the photomask varies depending on the conditions, but in the present invention, the pattern was produced with a size of 3 cm × 3 cm. FIG. 5 is a schematic diagram showing an example of the pattern of the photomask used in the present invention, and FIG. 6 is a schematic diagram showing an example of the entire photomask used in the present invention.
In FIG. 6, the size of the photomask is 5 inches × 5 inches, the pattern is divided into nine blocks, the pitch between each pattern is 0.85 cm, and the distance between the outer periphery of the photomask and the outer periphery of each pattern is 1 cm. is there.
In the present invention, by using a photomask, the cross-sectional shape orthogonal to the column axis direction of the plurality of louver rod structures of the anisotropic light diffusing layer can be formed into a desired substantially rounded rectangular shape. However, if the photomask pattern dimension is smaller than the wavelength when the uncured resin composition layer is irradiated with parallel light, the photomask pattern cannot be faithfully irradiated onto the uncured resin composition layer. You may be affected by the effect. As a countermeasure against this, a technique of previously providing optical proximity correction (OPC) to the mask pattern of the photomask can be applied.
By using the photomask, the cross-sectional shape perpendicular to the column axis direction of the plurality of louver rod structures of the anisotropic light diffusion layer can be formed as a desired substantially rounded rectangular shape.
Further, the photomask also serves to prevent oxygen inhibition when the uncured resin composition layer is cured.

[Example 1]
A PET film having a thickness of 100 μm and a size of 150 mm × 150 mm (trade name: A4100, manufactured by Toyobo Co., Ltd.) is used as a base material. A partition wall was formed. The height of the partition wall corresponds approximately to the thickness of the anisotropic light diffusion layer obtained. The partition wall is filled with a photocurable resin composition having the following composition to form an uncured resin composition layer, and then a glass substrate photomask made of a chromium film is formed on the surface of the uncured resin composition layer. (Thickness 2 mm) was laminated.
The photomask of the standard shown in FIG. 6 is used, the size is 5 inches × 5 inches, the pattern is divided into nine blocks, the pitch between each pattern is 0.85 cm, the outer periphery of the photomask and each pattern The distance from the outer periphery was 1 cm. FIG. 7 is a photograph of the appearance.
In addition, the standard pattern shown in FIG. 5 is used, and the size is 3 cm × 3 cm, and the substantially rounded rectangular shape has a long diameter line width Y of 1.5 μm, a parallel line width L of 0.9 μm, and a rounded radius width. r is 0.3 μm, the short-diameter line width S is 0.5 μm, the pitch between the substantially rounded rectangles in the long-diameter line width Y direction is 1.1 μm, and between the substantially rounded rectangles in the short-diameter line width S direction The pitch was 0.4 μm. FIG. 8 is a partial surface photograph thereof.
Silicone urethane acrylate (refractive index: 1.460, weight average molecular weight: 5,890) 20 parts by weight (trade name: 00-225 / TM18, manufactured by RAHN)
・ Neopentyl glycol diacrylate (refractive index: 1.450) 30 parts by weight (manufactured by Daicel-Cytec Corporation, trade name: Ebecryl 145)
· EO adduct diacrylate of bisphenol A (refractive index: 1.536) 15 parts by weight (manufactured by Daicel-Cytec Co., Ltd., trade name: Ebec r yl150)
・ Phenoxyethyl acrylate (refractive index: 1.518) 40 parts by weight (manufactured by Kyoeisha Chemical Co., Ltd., trade name: light acrylate PO-A)
・ 2,2-dimethoxy-1,2-diphenylethane-1-one 4 parts by weight (manufactured by BASF, trade name: Irgacure 651)
Parallel rays (wavelength: emitted from an irradiation unit for incident light of a UV spot light source (trade name: L2859-01, manufactured by Hamamatsu Photonics Co., Ltd.) from the photomask surface on the uncured resin composition layer on which the photomask is laminated. 365 nm ultraviolet rays) was irradiated for 1 minute with an irradiation intensity of 5 mW / cm ² , and further, ultraviolet rays with an irradiation intensity of 20 mW / cm ² were irradiated from the substrate side to be completely cured. From there, the base material and the photomask were peeled off to obtain the anisotropic light diffusion layer (anisotropic optical film) of Example 1.

[Example 2]
After laminating a glass substrate photomask (thickness 2 mm) with a chromium film on the surface of the uncured resin composition layer , the substrate side of the uncured resin composition layer is placed on a hot plate heated to 80 ° C. Anisotropic light diffusion of Example 2 is performed in the same manner as in Example 1 except that air is blown from the blower from the mask surface and irradiated with parallel rays from the photomask side of the uncured resin composition layer. A layer (anisotropic optical film) was obtained.
Further, when the thickness direction of the anisotropic light diffusion layer (direction perpendicular to the plane of the anisotropic light diffusion layer) was confirmed with an optical microscope, it had two diffusion center axes, and the thickness direction of the anisotropic light diffusion layer was 0 °. In this case, each diffusion center axis had a bent structure with inclinations of 0 ° and 15 ° and a bending angle of 15 °.

[Comparative Example 1]
Other than laminating a glass substrate photomask made of chromium film on the surface of the uncured resin composition layer, a PET film having a thickness of 50 μm and a size of 150 mm × 150 mm (made by Toyobo Co., Ltd., trade name: A4100) In the same manner as in Example 1, the anisotropic light diffusion layer (anisotropic optical film) of Comparative Example 1 was obtained.
In the anisotropic light diffusing layer of Comparative Example 1, a plurality of pillar structures are formed in the anisotropic light diffusing layer, not a plurality of louver rod structures, and a cross-sectional shape orthogonal to the column axis direction of the plurality of pillar structures is When confirmed with an optical microscope, it was substantially circular.

As shown in the above results, the anisotropic light diffusion layers (anisotropic optical films) of Examples 1 to 4 have good maximum linear transmittance, minimum linear transmittance, diffusion width, glare, and rapid change in luminance. In particular, Examples 2 and 3 gave better results. This is because, in the anisotropic light diffusion layer of the anisotropic optical film, the shape of the cross section perpendicular to the column axis direction (thickness direction of the anisotropic light diffusion layer) of the plurality of louver rod structures is optimized. By adopting a rectangular shape, the lens effect that moderately diffuses the light emitted from the anisotropic light diffusing layer is manifested, suppressing glare and sudden changes in brightness due to light interference, and optimizing the balance of optical properties including light diffusivity It is thought that it was possible.
Furthermore, since the anisotropic light-diffusion layers of the present invention in Examples 1 to 4 were within the range of the rounded radius width defined above, the diffusion width could be widened.
The reason why the diffusion width of Example 3 is large is considered to be that the louver rod structure was appropriately inclined, and the reason why the diffusion width of Example 2 was the largest was that the louver rod structure. because it has a cylindrical axis direction in the bent and spread more areas to diffuse light strongly, presumably because it is possible to further increase the diffusion width.

Claims (9)

An anisotropic optical film in which the amount of transmitted light changes depending on the incident light angle of light,
The anisotropic optical film has at least one anisotropic light diffusion layer,
The anisotropic light diffusion layer is
A plurality of louver rod structures and a matrix region;
Sectional shape perpendicular to the cylindrical axis direction of the louver rod structure, each ends of two substantially parallel lines, Ri substantially square RoundRectangle der which connects in a substantially circular arc,
The parallel line width of the two substantially parallel lines is L, the long diameter line width of the substantially long diameter line which is the maximum width of the substantially rounded rectangle is Y, and (Y−L) / 2 is the rounded radius width r. The anisotropic optical film characterized by satisfying Formula 2r <L <10r .   2. The anisotropic optical film according to claim 1, wherein the length of r is in a range of 0.01 μm or more and less than 0.4 μm. The anisotropic optical film according to claim 1, wherein Y is in a range of 0.5 μm to 50.0 μm.   The width of the minor axis that is the substantially rounded rectangular width in the direction perpendicular to Y is S, and the value obtained by dividing S by r is in the range of 0.4 to 10.0. The anisotropic optical film according to claim 1, wherein the anisotropic optical film is characterized in that: The louver rod structure has one inclination in the column axis direction, and the inclination is within a range of ± 70 ° when a normal direction to the plane of the anisotropic light diffusion layer is 0 °. It exists, The anisotropic optical film of any one of Claims 1-4 characterized by the above-mentioned. The louver rod structure is bent and extended in the column axis direction, and a bending angle thereof is in a range of 10 ° to 40 °. The anisotropic optical film as described in the item.   The anisotropic optical film according to claim 1, wherein a thickness of the anisotropic light diffusion layer is in a range of 10 μm to 100 μm. The maximum linear transmittance, which is the linear transmittance of light incident on the anisotropic light diffusing layer at an incident light angle that maximizes the linear transmittance of the anisotropic light diffusing layer, is in the range of 35% to 95%. The minimum linear transmittance, which is the linear transmittance of light incident on the anisotropic light diffusing layer at an incident light angle at which the linear transmittance of the isotropic light diffusing layer is minimum, is in the range of 25% or less. The anisotropic optical film of any one of 1-7. A diffusion width that is a width of an incident light angle range of two incident light angle values with respect to a linear transmittance that is an intermediate value between the maximum linear transmittance and the minimum linear transmittance is in a range of 30 ° to 80 °. The anisotropic optical film according to claim 8, wherein the anisotropic optical film is present.

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