TWI494611B - Louver sheet and method for manufacturing louver sheet - Google Patents

Description

Grid and grid manufacturing method

The present invention relates to a louver sheet having a high contrast and a high total light transmittance, and a method of manufacturing the grid.

In a display such as a liquid crystal display or a plasma display, a functional film having an anti-reflection function, an anti-glare function, an electromagnetic wave shielding function, a near-infrared shielding function, or the like is usually disposed on the viewing side of the display. Further, in order to suppress a decrease in contrast due to external light, a filter for display including a grid in which a plurality of light-shielding portions are arranged in a stripe shape has been proposed (Patent Documents 1, 2, and 3). The grid is also used in automatic teller machines (ATMs), portable phones, and personal computers to prevent peeping. In addition, the grid is also used in automotive driving guidance systems, so that the image is not reflected in the front glass, or used to limit the viewing direction. These grating sheets form a lens layer having a stripe-like convex portion composed of an ultraviolet curable resin on a transparent substrate, and fill the convex portion of the lens layer with the convex portion and the convex portion by a black substance capable of absorbing light. A light shielding portion is formed.

In order to effectively suppress the contrast reduction caused by external light, it has been conventionally to provide a light-shielding portion having a height of 100 μm or more, and the grid having the light-shielding portion needs to be able to reduce the visibility of the display image of the display. Since the amount of the light-shielding portion (the period in which the light-shielding portion is repeated) is always set to 50 μm or more. That is, the previous shading portion has been designed to have a high height and a wide pitch. Since the deep groove is formed in the formation process of the light shielding portion and the black substance is filled in the groove, the use amount of the light shielding material is large in the manufacturing steps of the light shielding portion, and the filling of the groove is likely to be insufficient to cause productivity. Low disadvantages.

Therefore, in order to improve the cost or the usability of the sheet, a grid in which the pitch of the light shielding portion and the width of the light shielding portion are made narrow has been proposed (Patent Document 4). Since the height of the light shielding portion can be reduced by making the pitch or the width of the light shielding portion narrow, the amount of the resin material can be reduced and the cost can be reduced.

Further, a method of manufacturing a grid in which the width of the light-shielding portion is made narrow by the light-shielding material so that the lens layer is swollen is proposed (Patent Document 5).

Prior technical literature Invention patent document

Patent Document 1 Japanese Patent Application Laid-Open No. 2004-62084

Invention Patent Document 2 Japanese Invention Patent Laid-Open No. 2006-201577

Patent Document No. 3 Japanese Patent Application Laid-Open No. 2006-189867

Invention Patent Document 4 Japanese Patent Application Laid-Open No. 2008-304674

Patent Literature No. 5 Japanese Patent Application Laid-Open No. 2009-139493

According to the invention of Patent Document 4, a mold having a plurality of blades arranged in parallel is pressed against the lens layer to form a groove for filling the light shielding portion in the lens layer. However, in order to make the pitch or the width of the light-shielding portion narrow, the blade width of the non-reduced mold or the interval between the blade and the blade is not sufficient, and thus the moldability of the mold is deteriorated. Moreover, the mold release property of the mold and the lens layer is also deteriorated, and defects are easily generated to cause a decrease in yield.

According to the manufacturing method of Patent Document 5, it is not necessary to reduce the blade width of the mold, and therefore the moldability of the mold is good. In addition, the mold release property of the mold and the substrate is also good, and the production efficiency is increased. However, when the lens layer is swollen with a light-shielding material, the boundary between the light-shielding portion and the lens layer becomes blurred to cause a decrease in total light transmittance.

In view of the above, an object of the present invention is to provide a grid which can effectively suppress a decrease in contrast due to external light and which has a high total light transmittance. Still further, it is an object of the present invention to provide a method of manufacturing such grids at low cost and with good productivity.

The present invention is a grid comprising: a resin sheet having a plurality of parallel grooves formed on a first side; and a gate portion formed of a gate material filled at least at a bottom portion of the groove; and The aperture ratio of the first surface of the sheet viewed in the vertical direction is 80% or more, and the width of the gate portion is 0.1 μm or more and 5 μm or less in a cross section perpendicular to the long axis direction of the groove. The ratio W/H of the widest width W to the height H of the portion is 0.01 or more and 0.2 or less.

Further, the present invention is a method of manufacturing a grid comprising: a step (A) of molding a resin sheet having a plurality of parallel grooves on one side; and filling the gate material at least in the step (A) Step (B) at the bottom of the groove; and step (C) of pressing the resin sheet toward the thickness direction of the sheet to narrow the width of the groove.

According to the present invention, it is possible to provide a grid which can effectively suppress a decrease in contrast due to external light and which has a high total light transmittance. Also, the above-described grid sheet can be manufactured at low cost and with good productivity.

[Best Embodiment of the Invention] [grid]

Several embodiments of the grid of the present invention are described below with reference to the drawings. Fig. 1(a) is a perspective view of a grid sheet of the present invention. The grid 1 is formed with a gate portion 3 having a plurality of parallel stripe shapes inside the resin sheet 2. The gate portion 3 is formed with a plurality of parallel grooves on the surface on one side of the resin sheet 2, and is filled with a material for imparting optical characteristics such as light blocking property or light diffusibility in the groove (hereinafter, referred to as "gate material"). ) formed. Hereinafter, the surface on which one side of the groove having the resin sheet is formed is referred to as "face 4".

The gate material is a combination of various coloring agents in addition to an opacifier or a light diffusing material. If the opacifier is filled as a gate material, the contrast enhancing film or the security film can be used for the display as described above. When the light-diffusing material is filled, it is possible to extract light for use in a brightness enhancement film such as a backlight or a surface light-emitting body such as an organic electroluminescence light. As in the above various fields, it is useful to use a grid having a high aperture ratio and a fine groove. Hereinafter, the description will be focused on the manner in which the opacifier is filled as a gate material, but the present invention does not limit the gate material to an opacifier. In the present invention, the gate portion for the purpose of the light shielding property is referred to as a "light shielding portion", and the gate material for forming the light shielding portion is referred to as a "light shielding material".

The grid does not require a complete landfill, as long as it satisfies the relationship between width and height as will be described later, at least the bottom of the trench may be filled, and voids or other components may be present inside. Further, the grooves or the gate portions need not be strictly parallel, as long as they are not sized to cross each other or the gate portions at the size of the grid for practical application, and may be slightly offset from parallel.

Next, referring to Fig. 1(b), Fig. 1(c) and Fig. 8, the shape of the grid portion 3 will be described in detail. Fig. 1(b), Fig. 1(c) and Fig. 8 are cross-sectional views showing the grid sheet cut along a plane perpendicular to the longitudinal direction of the groove of the resin sheet. Fig. 1(b) is a schematic cross-sectional view showing one of the grid sheets of the present invention. Fig. 1(c) is a cross-sectional view showing another mode of the grid sheet of the present invention. Figure 8 is a further schematic cross-sectional view of the grid of the present invention, with the grid portion enlarged.

The p, W, and H in Fig. 1 (b), Fig. 1 (c), and Fig. 8 are explained below.

p is the pitch of the groove (repetition cycle). The end point of the pitch p is a point at which the line of the side wall of the groove intersects the line of the surface of the resin sheet.

W is the width of the thickest portion of the grid. The width W is the boundary line (line division) in which the side walls of the grid portion and the groove are drawn, and the longest interval among the intervals of the two boundary lines facing each other in the direction parallel to the surface of the resin sheet. The details are as follows in the eighth drawing. Draw the boundary line between the grid and the side wall of the trench (dashed lines 13, 14), and parallel between the boundary line on the left side of the drawing view (dashed line 13) and the boundary line on the right side of the figure view (dashed line 14) The longest interval among the intervals in the direction of the surface of the resin sheet is the width W.

H is the height of the grid. The height H is a distance from the line closest to the surface of the resin sheet to the line farthest from the surface of the resin sheet among the lines traversing the gate portion in a line parallel to the surface of the resin sheet.

The cross-sectional shape of the grid portion is not particularly limited and may be, for example, any of a rectangular shape, a trapezoidal shape, or a triangular shape. Among these, a rectangle is preferred to increase the total light transmittance from a direction perpendicular to the surface of the grid.

The widest width W of the gate portion is 0.1 μm or more and 5 μm or less. When W is less than 0.1 μm, it is difficult to form a groove in the resin sheet. Further, in the case of the gate portion for the purpose of shielding light, the light blocking rate of light entering the width direction of the gate portion is lowered, so that the contrast of the bright portion is insufficient. Further, when it exceeds 5 μm, the amount of use of the gate material is increased, the thickness of the entire sheet is increased, or the image accuracy for use in a display is lowered. The lower limit of W is preferably 0.5 μm or more, and more preferably 1 μm or more. The upper limit of W is preferably 4 μm or less, more preferably 3 μm or less.

The ratio W/H of the widest width W to the height H of the gate portion is set to be 0.01 or more and 0.2 or less so as not to cause the viewing angle to be extremely narrow and to obtain a good contrast. When W/H is less than 0.01, the visibility becomes extremely narrow or the gate portion is hard to be formed, so that productivity is deteriorated. If W/H is more than 0.2, since the aperture ratio as described later has to be reduced to maintain the contrast of the bright portion, the problem of lowering the total light transmittance is caused. Therefore, when used in a display, the power consumption is increased by the need to maintain the luminance emitted to the viewer side. The lower limit of W/H is preferably 0.05 or more, more preferably 0.1 or more. The upper limit of W/H is preferably 0.15 or less, more preferably 0.12 or less.

The height H of the gate portion is preferably 5 μm or more and 200 μm or less. When H is less than 5 μm, it is difficult to form a groove in the resin sheet, or it is difficult to set W/H to the above range. On the other hand, when it exceeds 200 μm, the amount of use of the gate material is excessively increased, or the thickness of the entire gate sheet is also thickened, which is not preferable. The lower limit of the height H is more preferably 10 μm or more. The upper limit of the height H is more preferably 100 μm or less.

The aperture ratio of the grid viewed from the direction perpendicular to the surface of the resin sheet was 80% or more. The "opening ratio" referred to herein is a value defined by the formula (p-W) / p × 100. In either of the first pattern (b) and the first pattern (c), or when the cross-sectional shape of the grid portion is approximately rectangular or about triangular, the aperture ratio is also defined by the above formula.

The resin constituting the resin sheet is not particularly limited as long as it is a resin which can be molded into an arbitrary shape by pressurization (hereinafter referred to as "pressure-formable resin"). From the viewpoint of easily applying deformation by pressurization, the pressure-mouldable resin is preferably a thermoplastic resin. Among the thermoplastic resins, an amorphous resin is more preferable. Since the amorphous resin is excellent in transparency, it is suitably used as a resin for optical sheets used for displays and the like. In addition, when the film is formed by melt extrusion, the amorphous resin does not require a rapid cooling measure such as a crystalline resin, and can be cooled slowly, and in particular, a sheet having excellent thickness accuracy can be obtained. membrane. The main component of the resin constituting the resin sheet is preferably a cyclic polyolefin resin, a polycarbonate resin, a polystyrene resin, an acrylate resin, a polyvinyl chloride resin, a polyolefin resin, or an amorphous polyester resin. In addition, the "main component of the resin" is the one that occupies the most mass among the materials constituting the resin. The resin material may be a mixture of, for example, the aforementioned resins, or may not contain an antistatic agent or a modifier as needed, without impeding the efficacy of the present invention. Among these, the cyclic polyolefin resin is particularly excellent in that it has excellent transparency, yellowing resistance, moisture permeability, and dimensional change is extremely small.

The resin sheet may be a sheet composed of only a single layer or a laminated sheet of two or more layers from the viewpoint of strength retention and the like. When the laminated sheet is composed of two or more layers, the outermost layer of any of them may be composed of a resin which can be formed by press molding. Further, the layer other than the layer is not necessarily a resin which can be press-formed as long as it can maintain the strength of the entire resin sheet.

The Tg of the resin for press molding which constitutes the outermost layer of the side for molding is preferably 80 ° C or higher. The Tg in the present invention is a value obtained by measuring a half point glass transition temperature by a differential scanning calorimeter according to JIS K 7121-1987. In the case of a grid for use in a display or a home appliance, the durability test is usually a test in which heating is performed only or under heating and humidification conditions. The temperature is mostly 60 to 80 ° C, and the relative humidity is in the range of 80 to 95%. Further, it is also an important condition for the resin sheet to be formed by press molding of the surface and not causing deformation under the temperature and humidity range under the durability test. That is, the Tg of the resin for press molding which forms the outermost layer of the side for molding is preferably 80 ° C or higher which is set to a temperature higher than the endurance test temperature. When the Tg is less than 80 ° C, there is a possibility that the shape of the sheet surface is deformed or the flatness of the sheet itself is deteriorated when the durability test is performed. The Tg is preferably from 80 to 180 ° C, more preferably from 90 to 160 ° C. When the Tg exceeds 180 ° C, sometimes the shape of the mold to be formed on the surface of the resin sheet must be set to a high temperature of 200 ° C or higher, thereby causing a decrease in the durability of the mold or a need to pay in the molding step. A lot of energy.

Examples of the resin sheet other than the thermoplastic resin are, for example, a resin which is hardened by ionizing radiation such as ultraviolet rays or electron beams, an oligomer, a monomer, a mixture of these, or the like, or a hardenability of a thermosetting composition or the like. Resin, laminated on the substrate sheet. In particular, the ionizing radiation-hardening composition is excellent in productivity because of its high curing rate, and is excellent in durability against a coating composition and a solvent used when the gate material is filled. A method of forming a groove on a resin sheet is, for example, a method in which the curable resin is laminated in an uncured state on a base sheet, and then a mold having a convex portion corresponding to the groove is pressed and cured. In addition, the substrate sheet can be used with various plastic films, such as polyester, polyolefin, polystyrene, polyamide, polyimide, polycarbonate, fluororesin, polyfluorene, polyether, epoxy resin, etc. The constituents. Further, two or more kinds of resins may be used in combination or in a laminated manner as needed. The base sheet is comprehensively selected from the viewpoints of necessary optical characteristics or physical properties, adhesion to the laminated resin, and the like.

The resin sheet preferably has a light transmittance of 85% or more in a state before forming the groove, and preferably has a haze of 5% or less. When the light transmittance is 85% or more and the haze is 5% or less, excellent light transmittance can be exhibited in a portion other than the gate portion to obtain a screen luminance or the like.

[grid material]

As the gate material for forming the gate portion, a coating agent obtained by dispersing or dissolving the colorant in the matrix composition, or a coating agent obtained by dispersing or dissolving the coloring agent in a solvent may be used.

In the coating agent obtained by dispersing or dissolving the colorant in the matrix composition, the matrix composition is preferably a resin, an oligomer, a monomer, and a mixture thereof which are hardened by ionizing radiation such as ultraviolet rays or electron beams. A curable resin such as a thermosetting composition. In particular, the ionizing radiation-hardening composition is excellent in productivity because it has a high curing rate and is excellent in durability against a coating composition and a solvent to be used for coating the gate portion. As the matrix composition, a polyfunctional acrylic hardening coating or a lanthanide hardening coating which is commercially available can be used. For these hardening coatings, Mitsubishi Rayon Co., Ltd. (trade name "DIABEAM" series, etc.), Nagase Industrial Co., Ltd. (trade name "DENACOL" series, etc.), Shin-Nakamura can be used. Chemical Industry Co., Ltd. (Shin-Nakamura Chemical Co., Ltd.) (trade name "NK Ester" series, etc.), Dainippon Ink and Chemicals, Inc. (trade name "UNIDIC") Series, etc., Toagosei Co., Ltd. (trade name "ARONIX" series, etc.), NOF Corporation (trade name "Blemmer" series, etc.), Nipponization Nippon Kayaku Co., Ltd. (trade name "KAYARAD" series, etc.), Kyoeisha Chemical Co., Ltd. (trade name "LIGHT ESTER" series, "LIGHT ACRYLATE series, etc., JSR Corporation (trade name "DeSolite" series), Shin-Etsu Chemical Co., Ltd. (trade name "X-62-7655" ) and other products. In these matrix compositions, a hardener or a polymerization initiator may be added as needed.

In the case where the gate portion is provided for the purpose of shielding light, the gate material is preferably a composition obtained by mixing a black pigment dispersion or a black dye in the matrix composition as a main component, and the above-mentioned difunctional is added as needed. A coating agent obtained by the following acrylate, polymerization initiator, and modifier.

The black pigment dispersion is a polymer dispersion including a black metal oxide such as carbon black, titanium or iron. When the absorption coefficient of the black pigment dispersion is about 1 × 10 ⁶ m ^-1 , the content of the black pigment dispersion is from 1 to 300 parts by mass, preferably 10, per 100 parts by mass of the above-mentioned matrix composition. It is preferably 100 parts by mass, more preferably 10 to 50 parts by mass. If it is less than 1 part by mass, the light blocking function cannot be exhibited. If it is more than 300 parts by mass, the light-shielding material is not easily filled into the groove due to the high viscosity.

Further, it may be diluted with a general organic solvent to adjust the viscosity of the obtained matrix composition by dispersing or dissolving the colorant. For example, an alcohol such as ethanol or IPA (isopropyl alcohol), a ketone system such as MEK (methyl ethyl ketone) or acetone, an aromatic system such as toluene or xylene, or an ester such as ethyl acetate or butyl acetate may be used. A chlorine-based solvent such as dichloromethane or chloroform may be appropriately selected in accordance with the substrate substrate to be used and the matrix composition of the gate material.

It is also a preferred mode for the gate material to use only the colorant dispersed or dissolved in a solvent. The colorant disperser is obtained by, for example, dispersing carbon black having a number average particle diameter of about 30 to 500 nm in various solvents. The ink for dissolving the coloring agent can also be used, for example, for various inks used in pens or ink pens that have been marketed. In this case, the concentration of the colorant may be selected in accordance with the desired transmittance, and is preferably from 1 to 50% by mass, more preferably from 3 to 20% by mass based on the total of the coating material. When the content of the colorant is less than 1% by mass, there is a possibility that the light-shielding property or other optical characteristics are insufficient. If the content exceeds 50% by mass, there is a possibility that the viscosity of the coating is too high to be easily applied.

Further, when only a coloring agent is dispersed or dissolved in a solvent, a dispersing agent or an auxiliary agent required for dissolution may be added in order to improve the dispersibility or solubility of the coloring agent. The solvent includes, for example, an alcohol such as ethanol or IPA (isopropyl alcohol), a ketone system such as MEK (methyl ethyl ketone) or acetone, an aromatic system such as toluene or xylene, or an ester system such as ethyl acetate or butyl acetate. A chlorine-based solvent such as dichloromethane or chloroform, or water may be used, or a mixture of two or more solvents may be used.

Further, in order to sufficiently adsorb the coloring agent on the surface of the groove of the resin sheet, it may be preferably a resin which is slightly dissolved in the substrate to be formed as a groove, or a solvent which dissolves in the substrate resin. mode.

The gate portion does not necessarily need to completely fill the groove of the resin sheet, and if it satisfies the relationship that W/H is 0.01 or more and 0.2 or less, at least the bottom of the trench may be filled. When the gate material is filled in the trench, if the gate material is filled more than the trench capacity, the gate material overflowing from the trench covers a portion of the surface of the resin sheet, so that the transmittance of the portion which should be the light transmitting portion is lowered. Therefore, it is preferred to fill the gate material to a small amount with respect to the groove capacity, or to fill the groove capacity or more, and to remove excess gate material in an appropriate manner after filling. In the case where excess gate material is removed after filling, it is generally preferred to select a cleaning method such as only preferentially washing or stripping the gate material. In the case where the gate material is filled with less gate material, or the case where excess gate material is removed after filling, the groove of the resin sheet may occur near the surface of the resin sheet and is not the gate portion. The case of the filled part.

As shown in Fig. 7(b), the shape of the groove which is not filled in the gate portion is preferably in the cross section perpendicular to the long axis direction of the groove of the resin sheet to be in the boundary with the gate portion. The line is about the upper trapezoid. The so-called "upper bottom" is the shorter of the parallel sides of the trapezoid. In addition, the so-called "lower bottom" is the longer one of the parallel sides of the trapezoid. The so-called "about trapezoid" means that even if the upper base or the two sides connecting the upper and lower bottoms are not straight, they can be regarded as the boundary line with the grid (16 of Fig. 7(b)). The line connecting the surface of the resin sheet (17 of Fig. 7(b)) has a shape of a trapezoidal shape of the lower base. When the above-mentioned grid sheet is used as a filter for a display, most of the functional layer is laminated on the surface of the resin sheet through the adhesive material. When the thickness W of the gate portion is 5 μm or less, if the space of the portion not filled with the gate portion is a rectangle or the surface of the resin sheet is narrow, the adhesive material may not be completely filled. Space and air are easily entrained to create a bright and dazzling situation. If the shape of the space is about a trapezoidal shape with the boundary of the grid portion as the upper bottom, the adhesive material can be easily filled with the gap to be dense without causing deterioration of image quality, which is preferable.

In the vicinity of the surface of the resin sheet of the groove, there is a portion of the groove which is not filled with the gate portion, and a portion of the shape of the portion of the resin sheet which is not filled with the gate portion and the boundary portion of the gate portion is an upper portion, which can be easily used by the following. The manufacturing method of the present invention is described.

[Method of manufacturing grid]

The manufacturing method of the grid sheet of the invention comprises three steps:

(A) a step of forming a resin sheet having a plurality of parallel grooves on one side surface;

(B) a step of filling the gate material into at least the bottom of the trench;

(C) a step of pressurizing the resin sheet in the thickness direction of the sheet to narrow the width of the groove. When the step (A) is first performed, the step (B) and the step (C) may be performed first. One mode of the step (A) is shown in Fig. 2, and one of the steps (B) and (C) is shown in Fig. 4. Although the step (C) is carried out after the step (B) in Fig. 4, of course, the order may be reversed. The second and fourth figures will be described in detail later.

According to this manufacturing method, a grid having a narrow width of the gate portion can be obtained. Further, it is possible to easily obtain a gate having a widest width W of the gate portion of 0.1 μm or more and 5 μm or less, an aperture ratio of 80% or more, and a ratio W/H of W to the height H of the gate portion of 0.01 or more and 0.2 or less. sheet.

In the case where step (C) is carried out before step (B), if an appropriate grid shape is to be obtained, it is necessary to stop in the process of pressing the resin sheet to deform the groove in step (C), and The temperature, pressure, time, and the like of the pressurizing step are strictly adjusted so that the temperature or pressure distribution gradient in the surface of the resin sheet is extremely reduced. Depending on the material of the resin sheet to be used or the combination of the gate materials, if the step of filling the gate material of the step (B) is preferentially performed, a step required to obtain the same shape can be set by this (C) The range of pressurization step conditions.

Conversely, in the case where step (B) is carried out before step (C), when the pressurization of step (C) is performed, since it is possible to be affected by the filled gate material, the available gate material is A situation that may be limited. The case of the step (C) is carried out before the step (B), since no more materials can be used as the gate material without such restrictions. Therefore, whether or not the steps (B) and (C) should be prioritized should be comprehensively judged from the characteristics of the grid to be manufactured, and the like.

Next, the steps (A), (B) and (C) are respectively described in detail below.

[Step (A)]

First, the description of the step (A) using the second drawing will be described below. Fig. 2 is a view showing a step of pressing a pattern mold 5 having a convex portion on the resin sheet 6 from the side of the resin sheet to form a groove corresponding to the shape of the convex portion on the resin sheet. The shape of the convex portion of the pattern mold 5 is a shape obtained by reversing the shape of the groove to be formed on the resin sheet.

The pattern mold 5 and the resin sheet 6 are placed in a state of being caught by the temperature regulating sheets 21 and 22. The temperature regulating plates 21 and 22 are internally provided with a heating source such as a heater and a cooling source such as a refrigerant flow path, and can be heated and cooled to an arbitrary temperature. Moreover, the temperature adjustment plates 21 and 22 are attached to a pressurizing device (not shown), and the pattern mold 5 and the resin sheet 6 can be pressed in the thickness direction of the sheet with a desired pressure.

First, the temperature adjustment plates 21 and 22 are heated to raise the temperature of the pattern mold 5 and the resin sheet 6 mounted in advance to a specific temperature. The temperature is controlled such that the temperature of the pattern mold and the resin sheet 6 is within a temperature range of the glass transition temperature Tg of the resin constituting the resin sheet 6 and Tg + 60 ° C or lower (Fig. 2 (a)). The reason for controlling to the above temperature range is that if the temperature is lower than Tg, the moldability is not good, and if it is higher than Tg + 60 ° C, the elastic modulus of the film is too low, so that the sheet cannot be maintained. Flatness.

Next, the resin sheet 6 and the pattern mold 5 are pressed under pressure as desired. The pressure range is preferably controlled in the range of 0.1 MPa to 20 MPa, and more preferably in the range of 1 to 10 MPa. In addition, a cushioning elastomer or cushioning material may be interposed between the sheet and the temperature regulating plate or between the mold and the temperature regulating plate so that pressure can be uniformly applied to the molding region.

Next, after maintaining the time required for molding the resin while still applying pressure, the temperature adjustment plate is cooled while the pressure is still maintained, so that the temperature of the sheet is lowered.

Next, after the temperature of the sheet is lowered to a temperature lower than the glass transition temperature Tg of the resin constituting the sheet, the pressure is released, and the lens sheet is released from the mold (Fig. 2(d)).

The sheet is attached to the mold surface and released from the mold, and the optimum apparatus can be suitably used in response to, for example, a continuous or sheet-like product form or molding area. Further, it is not limited to the above method and configuration as long as it is a process in which the shape of the desired pattern is transferred by pressing the mold by heating and softening the resin, and then the resin is cooled and solidified.

Further, in the method of patterning the surface of the sheet, in addition to the method of intermittently molding using a flat mold as shown in Fig. 2 (intermittent molding method), it is also possible to use a roll-shaped mold having a pattern on the surface or an endless skin. A strip mold is used to form a continuous mold (continuous molding method). In the case of the batch molding method, since the pressure can be maintained for a long period of time, it is excellent in a pattern which can be formed fine and has a high aspect ratio. In the case of the continuous molding method, the pattern shape accuracy is inferior to the batch molding method, but in terms of productivity, it is superior to the batch molding method.

The manufacturing method of the mold used in the step (A) will be described below. First, a machining tool having the same shape as the concave shape of the desired cross section is used on the shaping surface side of the mold material, and the machining is performed by an ultra-precision machining machine capable of performing three-dimensional machining, whereby the shaping surface can be imparted Convex shape section. Ultra-precision processing machines are known, for example, in various ways such as a planer (shaper) method, a wing cut method, an end mill method, and a lathe processing method. Among them, it is preferable to use the highest precision planer (head planer) method and wing cutter method.

A method of molding a resin sheet having a groove, in addition to a method of extruding a mold to a resin sheet, a method by extrusion molding is also possible. This method is a method in which a resin of a sheet is melt-extruded, and then pressed against a transfer roller having a shape obtained by reversing a pattern to be transferred. This method has the disadvantage that the pattern shape accuracy is lower than that of the above method because the resin temperature is still high, but the productivity is high because the film forming step and the molding step can be simultaneously performed. .

[Step (B)]

Next, the description of the step (B) using the third drawing will be described below. The filling of the gate material is preferably carried out continuously in the state of a long sheet-like sheet. Further, it is important that the gate material is buried in the groove formed in the resin sheet without being entrained in the air. If an air layer such as a bubble exists in the groove, it may cause a rise in haze or a poor appearance. This problem can be solved by applying a gate material in parallel to the long axis direction of the groove. The coating method is not particularly limited as long as it can fill the gate material in the groove, but is preferably a micro-gravure rotation method or a bar coating method. After the gate material was previously diluted in a solvent, it was applied as shown in Fig. 3 (a). The solvent is used to be uniformly dispersed without being separated from the gate material. The dilution rate may be appropriately determined depending on the depth of the groove. Further, in the case where the step (C) is carried out after the step (B), the dilution ratio may be appropriately determined in accordance with the size of the gate portion to be molded by the pressurizing step of the step (C). A cross-sectional view of the coated resin sheet is shown in Fig. 3(b). Next, by drying the gate material, the gate material can be filled only in the groove portion as shown in Fig. 3(c). When the gate material is filled according to the above method of the present invention, not only the step of scraping the useless material after filling the gate material which is conventionally used in the production of the grid can be omitted, but also the scratch or contamination can be reduced to improve the quality.

[Step (C)]

Next, the description of the step (C) using the fourth drawing will be described below. Fig. 4 is a view showing a step of pressing the mold 12 against the resin sheet filled with the gate material in the groove as viewed from the side of the resin sheet, so that the width of the groove is deformed to be small.

The resin sheet and the mold are placed in a state in which the temperature adjustment plates 23 and 24 are placed next to each other. The temperature regulating plates 23 and 24 are cooling sources such as a heating source such as a heater and a refrigerant flow path, and can be heated and cooled to an arbitrary temperature. Further, the temperature regulating plates 23 and 24 are attached to a pressurizing device (not shown), and can press the mold and the resin sheet at a desired pressure in the thickness direction of the sheet.

The temperature adjustment plates 23, 24 are initially heated so that the mold 12 and the pre-installed resin sheet 11 filled with the gate material are heated to a specific temperature. Further, the temperature of the control mold 12 and the resin sheet 11 is within a temperature range of the glass transition temperature Tg of the resin constituting the sheet of Tg - 10 ° C or more and Tg + 50 ° C or less (Fig. 4 (a)). When the temperature is lower than Tg - 10 ° C, the portion between the groove and the groove of the resin sheet (hereinafter referred to as "the convex portion of the resin sheet") is not easily deformed. If the temperature is higher than Tg + 50 ° C, the deformation of the convex portion may be excessive, the groove may collapse, and the groove may disappear. More preferably, the temperature is controlled within a temperature range of Tg + 20 ° C or lower.

Next, the resin sheet 11 and the mold 12 are pressed under pressure as desired. The convex portion of the resin sheet is thickened while being subjected to an external force, and is compressed in the thickness direction of the resin sheet. As a result, the width of the groove between the convex portion and the convex portion is deformed to be small. The pressure range is preferably controlled in the range of 0.1 MPa to 20 MPa, more preferably in the range of 1 MPa to 10 MPa. In addition, a cushioning elastomer or cushioning material may be interposed between the sheet and the temperature regulating plate or between the mold and the temperature regulating plate so that pressure can be uniformly applied to the molding region.

Next, after the time necessary for maintaining the deformation of the convex portion in a state where the pressure is still applied, the temperature adjustment plate is cooled while the pressure is still maintained, so that the temperature of the resin sheet 11 is lowered.

Then, after the temperature of the resin sheet is lowered to a temperature lower than the glass transition temperature Tg of the resin constituting the resin sheet, the pressure is applied to release the resin sheet 11 from the mold (Fig. 4(d)).

The mounting of the resin sheet on the surface of the mold and the release from the mold may be carried out by appropriately using an optimum apparatus according to, for example, a continuous shape or a sheet-like product form or a molding area. Further, it is not limited to the above method as long as it is a process which deforms the convex portion by pressing the mold by heating and softening the resin.

Further, in addition to the batch molding method as described above, a continuous molding method may be employed. In the case of the batch molding method, since the pressure can be maintained for a long period of time, it is suitable for the case where the amount of deformation of the convex portion of the resin sheet is large. In the case of the continuous molding method, the amount of deformation is smaller than that of the batch molding method, but the productivity is excellent.

Further, in the case where the step (C) is carried out after the step (B), the condition for the deformation is preferably such that the elastic modulus of the gate material is lower than the elastic modulus of the resin sheet material, so that the deformation of the convex portion of the resin sheet It is not hindered by the gate material filled inside the trench. In the case where the modulus of elasticity of the gate material is higher than that of the resin sheet material, there is a possibility that the deformation of the groove shape is hindered.

In addition, the shape of the groove before deformation is preferably designed to be optimal in shape to obtain a desired shape after deformation. In particular, in the shape in which the side wall spacing is narrowed toward the bottom of the groove, it is preferable to obtain a certain groove width shape after being deformed. Moreover, it is preferable to set the bottom of the groove to be flat, and the distance between the sidewalls of the respective portions is to be longer than the distance between the sidewalls after the deformation. If the initial side wall spacing is too narrow, the recess will disappear when pressurized. Further, the groove shape before the deformation is formed in advance so that the width of the groove is a shape in which the surface side of the resin sheet is wider, whereby the groove shape of the portion which is not filled with the gate portion after the deformation can be easily formed. The boundary line with the grid is about the upper trapezoid.

[other steps]

Further, after the completion of the steps (B) and (C), as shown in Fig. 4 (e) and (f), the resin sheet is pressed again in the thickness direction by a mold having a flat surface or a smooth surface roller, so that the resin The surface of the sheet 11 is flattened. When the surface of the resin sheet is flat, the light is easily incident on the grid, and the problem that the light is scattered in an intended direction and the image is deteriorated can be eliminated. As a result, the total light transmittance increases and the haze becomes small, which is preferable. The condition of the pressurization may be a condition that the resin is not deformed and the resin is deformed in a state in which the convex portion of the resin sheet is flattened.

If it is desired to flatten only the surface of the resin sheet while suppressing deformation of the gate material, the gate material must be less deformable than the resin constituting the resin sheet when pressurized. Therefore, it is preferable to control the temperature of the mold and the resin sheet at the time of pressurization to be higher than the glass transition temperature of the resin constituting the resin sheet, and it is a range in which the elastic modulus of the gate material is not significantly lowered. For example, in FIG. 4(d), after the convex portion is deformed by pressurization, the gate material is cured by UV (ultraviolet) irradiation or the like, and then planarized.

The pressurization conditions are as follows. For example, the temperature of the temperature control resin sheet and the mold is within a temperature range of the glass transition temperature Tg of the resin constituting the resin sheet and Tg+60 ° C or lower. If the temperature is lower than Tg, the convex portion of the resin sheet is not easily deformed. If the temperature is higher than Tg + 60 ° C, there is a possibility that the groove of the filled gate material collapses. Further, the pressure range is preferably controlled in the range of 0.1 MPa to 20 MPa, more preferably in the range of 1 MPa to 10 MPa. In addition, a cushioning elastomer or cushioning material may be interposed between the sheet and the temperature regulating plate or between the mold and the temperature regulating plate so that pressure can be uniformly applied to the molding region. After the time and pressure necessary for the surface of the resin sheet to be flat are maintained, the pressure is released and the resin sheet is released from the mold. When demolding from the mold, it is preferred to cool the temperature of the mold and the resin sheet to a temperature lower than Tg to suppress the adhesion of the surface of the resin sheet or the surface of the resin sheet to be thick.

Further, when the surface of the resin sheet is smoothed, in order to smoothly deform or flow the resin, it is preferable to set the friction coefficient of the surface of the resin sheet and the pressing member contacting the surface to be small. For example, a resin sheet surface contact portion of a pressing member is formed of a film containing a high heat resistance fluororesin or a polyimide resin, or a low friction material such as diamond-like carbon is formed into a film. The surface of the component.

Further, if the surface of the resin sheet is not sufficiently flattened by one pressurization, the pressurization treatment can be carried out in many times.

In order to flatten the surface of the resin sheet, other layers may be laminated. For example, a method of laminating through an adhesive layer, or by coating a coating, drying, and hardening, is planarized. Further, the surface may be flattened by applying a solvent (substantially insoluble of the gate material) such that only the resin sheet can be dissolved or swollen. In this case, a mixed solvent containing the aforementioned solvent for dissolving or swelling may be used.

If a groove having a width near the surface of the resin sheet as shown in Fig. 1(c) is narrower than the bottom portion, it is difficult to obtain a good mold processing precision or transfer shape on the resin sheet. When it is not easy to pull out the mold. However, if the method of manufacturing the grid according to the present invention, such a shape can be obtained. Specifically, when the pressure is applied in the step (C), the temperature distribution gradient of the resin sheet on the surface side is lowered by setting the temperature distribution gradient of the resin sheet in the thickness direction closer to the surface side of the resin sheet. By deforming, a groove of such a shape can be produced.

"Embodiment"

Hereinafter, the measurement methods and evaluation methods of the respective examples and comparative examples will be described. The measurement was carried out under the conditions of a room temperature of 23 ° C and a relative humidity of 65% unless otherwise specified.

A.Tg determination

The measurement was carried out according to the guidelines of JIS K 7121-1987 and using differential scanning calorimetry. A 5 mg composition or film sample was filled in an aluminum dish. The sample was heated from room temperature to 300 ° C at a temperature increase rate of 20 ° C / min and melted for 5 minutes. Then, it was quenched with liquid nitrogen, and heated again from room temperature to a temperature increase rate of 20 ° C /min to 300 ° C, and at the second temperature rise, the glass transition temperature (intermediate point glass transition temperature) was measured, and this was used as the Tg. . The differential scanning calorimetry was performed using Robot DSC "RDSC220" manufactured by Seiko Electronics Industrial Co., Ltd. The data analysis device uses the Disc Station "SSC/5200" manufactured by the company.

B. Cross section observation

The grid is cut by being perpendicular to the long axis direction of the groove. The cross section of the grid was cut using a microtome and with a 3° slicing angle. Platinum-palladium was evaporated in a cross section. The cross section was adjusted to 10 to 5000 times using a scanning electron microscope so that five or more gate portions appeared in the field of view to take a photograph. Then, the dimensions of the groove and the gate are measured from the cross-sectional photograph. When the shape collapses at the time of cutting, the entire grid is immersed in liquid nitrogen, frozen, and then cut, or diced with another resin, and then cut to prevent the shape from collapsing. The slicer is a rotary slicer manufactured by Slicer Research Co., Ltd. The scanning electron microscope was a scanning electron microscope S-2100A manufactured by Hitachi, Ltd. (Hitachi, Ltd.).

[pitch pitch]

The cross-sectional photograph is measured to determine the size of the pitch of the groove. The so-called "pitch" here is the repetition period of the groove. The end point of the pitch is the point at which the line of the side wall of the groove intersects the line of the surface of the resin sheet. The measurement was performed on 10 randomly selected from a cross-sectional photograph, or randomly selected from a plurality of cross-sectional photographs, and then the average value thereof was used as the pitch p of the groove.

[H Height of Gate]

The size of the height of the gate portion is measured by selecting any of the gate portions in the cross-sectional photograph. The term "height" as used herein means a line which traverses the gate portion in a line parallel to the surface of the resin sheet, from the line closest to the surface of the resin sheet to the line farthest from the surface of the resin sheet. distance. The measurement was performed on 10 randomly selected from a cross-sectional photograph, or a total of 10 randomly selected from a plurality of cross-sectional photographs, and then the average value thereof was used as the groove height H of the groove.

[WW width of the gate]

The width of the width of the thickest portion of the gate portion is measured by selecting any of the gate portions in the cross-sectional photograph. The term "width" as used herein means the boundary line (line division) which draws the side wall of the grid portion and the groove, and the longest interval among the intervals of the two boundary lines facing each other in the direction parallel to the surface of the resin sheet. The measurement is performed on 10 randomly selected from a cross-sectional photograph, or a total of 10 randomly selected from a plurality of cross-sectional photographs, and then the average value thereof is used as the widest width W of the groove portion of the groove.

[The ratio of the widest width of the W/H gate to the height of the grid]

The height of the gate portion and the width of the thickest portion are measured by selecting any of the cross-sectional photographs, and then the ratio of (width/height) is calculated. The measurement was performed on 10 randomly selected from a cross-sectional photograph, or a total of 10 randomly selected from a plurality of cross-sectional photographs, and then the average value was taken as the ratio W/H.

[Determination of the shape of the unfilled portion of the groove of the resin sheet]

Whether or not any of the gate portions in the cross-sectional photograph is selected and the shape of the portion of the trench filled with the gate material that is not filled with the gate material is determined to be approximately trapezoidal with the boundary line of the gate portion as the upper substrate. In this case, if the height of the unfilled portion is 0.1 μm or more and the length of the boundary line of the gate portion is shorter than the width of the upper end of the opening portion, even if the upper bottom or the two sides connecting the upper bottom and the lower bottom are not straight lines, However, the boundary line with the grid (16 of Fig. 7(b)) can be regarded as the upper base and the line connecting the surface of the resin sheet (17 of Fig. 7(b)) can be regarded as the trapezoidal shape of the lower bottom. , is considered to be about trapezoidal. Judging from 10 randomly selected from a cross-sectional photograph or a total of 10 randomly selected from a plurality of cross-sectional photographs, if more than 8 or more have a trapezoidal shape, it is determined as a groove of the resin sheet. The shape of the unfilled portion is approximately trapezoidal in shape.

C. Light transmittance and haze of the resin sheet before groove formation

Haze is measured using a haze meter according to the criteria of ISO 14782:1999. The light transmittance is measured by the value of the total light transmittance and the diffuse transmittance calculated from the above haze measurement (total light transmittance - diffuse transmittance). In the measurement, the resin sheet was cut into a square of 80 mm square, and the sample was placed in a state in which the arbitrary side was horizontal. Further, the sample was turned over to measure the light transmittance and haze from the surface opposite to the above. Three samples were taken from one sample and each was measured once, and the average of the total of six data was taken as the light transmittance and the haze. The haze meter was a haze meter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.

D. Total light transmittance, haze

The total light transmittance is determined according to the criteria of ISO 13468-1:1996, and the haze is measured using a haze meter according to the criteria of ISO 14782:1999. The grid was cut into 80 mm squares, and this was mounted such that the light was incident from the side of the side where the groove was not formed, and the long axis direction of the groove was made to be the up and down direction. Three samples were sampled from one sample and each was measured once, and the three average values were used as the total light transmittance and haze. The haze meter was a haze meter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd.

E. Viewing angle characteristics

The exit intensity distribution of the grid was measured using a variable angle photometer. The grid was cut to an angle of 80 mm, and this was mounted on the sample stage so that light was incident from the side of the side where the groove was not formed, and the longitudinal direction of the groove was made to be the up and down direction. The light source and the light-receiving portion of the device were fixed so that the incident angle to the sample surface was in the range of -90° to +90° and was measured every 5°. The variable angle photometer is a variable angle photometer GP-200 manufactured by Murakami Color Research Laboratory Co., Ltd. The measurement conditions are as follows:

‧Light source: 12 V 50 W halogen lamp

‧Light source side filter: The light amount adjustment filter with an average transmittance of 1% and 10% is used in an overlapping manner.

‧ Beam aperture: set to 1 (Φ about 4 mm)

‧Acceptor aperture: set to 6 (Φ about 13 mm)

‧Testing table: Standard sample table with reflection and transmission pitch adjustment device

‧ Measurement mode: transmission

‧The sensitivity of light when the incident angle is 0° is assumed to be 100.

The evaluation was carried out by investigating the incident angle at which the value of the peak became 50% with respect to the sensitivity of the emitted light, and recorded the width value at which the peak was located at the - side and the angle at the + side. For example, when the incident angle with the highest sensitivity is 0° and the sensitivity when incident at 0° is 100, if the sensitivity of the emitted light reaches 50 degrees is -30° and +30°, it is recorded as 60°.

[Example 1]

A cyclic polyolefin resin (TOPAS 6013, Tg 136 ° C, manufactured by Polyplastics Co., Ltd.) was prepared as a resin for constituting a resin sheet. These were dried at 120 ° C for 6 hours and then melted at a temperature of 260 ° C. Next, the resin extruded through the melt extrusion die was extruded in a sheet form on a metal cylinder maintained at 100 °C. The speed of the metal cylinder was set to 25 m/min and taken up to obtain a resin sheet 1. The resin sheet 1 had a light transmittance of 91% and a haze of 0.4%.

Next, the following mold 1 and the resin sheet 1 were heated at 175 ° C for 1 minute, and while maintaining the temperature at 175 ° C, the mold 1 and the resin sheet 1 were pressed at a pressure of 2 MPa for 30 seconds. After cooling to 70 ° C, the resin sheet 1 was released from the mold. Thereby, a grooved resin sheet 1 having a pattern obtained by reversing the shape of the mold 1 is formed on one surface of the resin sheet 1 (step (A)).

(Mold 1)

‧In-plane pattern: striped

‧ Cross-sectional shape of the convex part: isosceles trapezoid (isosceles trapezoid)

‧ Height of the convex part: 65μm

‧Width of the convex part: (upper) 7μm, (bottom) 13μm

‧Pitch of the convex part: 35μm

‧ Size: 100 mm × 100 mm (pattern area).

Next, the grooved resin sheet 1 is pressed by the method shown in Figs. 4(a) to 4(d) (but the unfilled gate material) to obtain the grooved resin sheet 2. The pressure plate temperature at the time of pressurization was 135 ° C, the pressurization pressure was 2 MPa, and the pressure holding time was 30 seconds (step (C)).

Next, 20 parts by mass of carbon black was added as a 100 parts by mass of a chlorinated polyolefin coating (manufactured by Toyo Kasei Co., Ltd., manufactured by Toyo Kasei Co., Ltd., solid content concentration: 30%). The black material was stirred and made to produce the gate material 1.

The gate material 1 was applied by a bar coating method using a grooveless wire bar on the grooved resin sheet 2, and dried at 110 ° C for 1 minute. Further, the gate material 1 was again coated by a bar coating method using a grooveless wire bar, and dried at 110 ° C for 1 minute (step (B)).

Table 1 shows the results of the dimensions, total light transmittance, and viewing angle of each part. The W/H was 0.767, the aperture ratio was 86%, the total light transmittance was 83%, the haze was 5%, and the viewing angle was 65°.

[Embodiment 2]

The grooved resin sheet 1 was obtained in the same manner as in Example 1 (step (A)).

Next, 1 part by mass of a hardener (CAT-7605, manufactured by Shin-Etsu Chemical Co., Ltd.) and 100 parts by mass are added to 100 parts by mass of a lanthanide resin (X-62-7655, manufactured by Shin-Etsu Chemical Co., Ltd.). Carbon black as a black material and stirred. Next, the gate material 2 was produced by diluting with MEK (methyl ethyl ketone) to a solid concentration of 20%.

The grid material was applied by a bar coating method using a grooveless wire bar on the grooved sheet 1 and dried at 90 ° C for 1 minute (step (B)). Next, the gate material 1 was hardened by irradiating 1 J/m ² with an ultrahigh pressure mercury lamp. Next, pressurizing to obtain the grid sheet 2 by the method shown in Figs. 4(a) to (d) and at a pressure plate temperature of 130 ° C, a pressurizing pressure of 1.5 MPa, and a pressure holding time of 1 minute (step ( C)).

Table 1 shows the results of the dimensions, total light transmittance, and viewing angle of each part. The W/H was 0.1, the aperture ratio was 86%, the total light transmittance was 80%, the haze was 10%, and the viewing angle was 40°.

[Example 3]

A sample was produced in the same manner as in Example 2 except that the hardening of the gate material 1 irradiated by the ultrahigh pressure mercury lamp was changed to be carried out after the step (C) to obtain the grid sheet 3.

In Fig. 5, a cross-sectional photograph of the obtained grid sheet, the dimensions of the respective portions, the total light transmittance, and the viewing angle are shown in Table 1. It has W/H = 0.125, an aperture ratio of 86%, a total light transmittance of 85%, a haze of 5%, and a viewing angle of 65°.

[Example 4]

The following mold 2 was heated at 145 ° C with an acrylate resin sheet 2 (Delaglas A999, manufactured by Asahi Kasei Chemicals Corporation, light transmittance of 92%, haze of 0.1%) having a thickness of 1 mm. The mold 2 and the resin sheet 2 were pressed at a pressure of 5 MPa for 30 seconds while maintaining the temperature at 145 ° C for 1 minute. Then, it was cooled to 70 ° C. The resin sheet 2 is released from the mold. Thereby, the grooved resin sheet 2 having the pattern obtained by inverting the shape of the mold 2 is formed on one surface of the resin sheet 2 (step (A)).

(Mold 2)

‧ Cross-sectional shape of the convex part: Isosceles trapezoid

‧ Height of the convex part: 80μm

‧Width of the convex part: (upper) 7μm, (bottom) 13μm

‧Pitch of the convex part: 35μm

‧ Size: 100 mm × 100 mm (pattern area).

Next, 30 parts by mass of carbon black as a black material is added to 100 parts by mass of a urethane resin coating (VYLON(R) UR-8300, manufactured by Toyobo Co., Ltd.). And stir. Next, the gate material 4 was produced by diluting with ethyl acetate to a solid concentration of 20%.

The gate material 4 was applied by a bar coating method using a grooveless wire bar on the grooved resin sheet 2, and dried at 90 ° C for 1 minute (step (B)). Next, pressurization was carried out at a pressure plate temperature of 135 ° C, a pressurization pressure of 1.5 MPa, and a pressure holding time of 1 minute in the method shown in Fig. 4 (a) to (d) to obtain a grid sheet 4 (step (C)).

Table 1 shows the results of the dimensions, total light transmittance, and viewing angle of each part. The W/H ratio was 0.089, the aperture ratio was 89%, the total light transmittance was 85%, the haze was 7%, and the viewing angle was 60°.

[Example 5]

The grooved resin sheet 2 was obtained in the same manner as in Example 4 (step (A)).

Next, a black ink was applied by a bar coating method using a grooveless wire bar (ink for securities (product number: INK-30-DO), manufactured by PILOT Corporation), and dried at 90 ° C for 1 minute ( Step (B)). Next, pressurization was carried out at a pressure plate temperature of 135 ° C, a pressurization pressure of 1.5 MPa, and a pressure holding time of 1 minute in the method shown in Fig. 4 (a) to (d) to obtain a grid sheet 5 (step (C)).

Table 1 shows the results of the dimensions, total light transmittance, and viewing angle of each part. The W/H was 0.067, the aperture ratio was 91%, the total light transmittance was 87%, the haze was 5%, and the viewing angle was 65°.

[Comparative Example 1]

The manufacturing was carried out using a manufacturing apparatus as shown in Fig. 6. 100 parts by mass of an ultraviolet curable composition (manufactured by DeSolite Z7528, manufactured by JSR Co., Ltd.) was heated to 70 ° C to have a low viscosity, and 10 parts by mass of carbon black was slowly added while stirring with a mixer. Disperse to make a black paint and use it as a gate material. The gate material is supplied from the supply device 32 to the groove of the mold roll 30 by the mold roll (mold 3) 30 with the following groove rotated in the direction of the arrow. The excess gate material supplied to the grooved mold roll 30 is scraped off by the doctor blade 33. Next, a PET film 34 (manufactured by Toray Industries, Inc., manufactured by Toray Industries, Inc., having a light transmittance of 91% and a haze of 0.9%) having a thickness of 100 μm continuously moved by a roll 35 was used. It is adhered to the mold roll 30 to which the groove is attached. PET film 34 with the groove in the state of adhesion of mold roll 30, the ultraviolet irradiation device 36 is irradiated to 1 J / m ² of ultraviolet light, such that the cured resin filled in the groove with the groove 30 of the mold roll. Next, the PET film 34 is peeled off by the return roller 37 from the grooved mold roll 30 to form a grid portion. Then, the mirror-formed roller 38 located on the surface side on which the grid portion is formed is supplied with the ultraviolet curable composition (DeSolite Z7528, manufactured by JSR Co., Ltd.) from the resin supply device 40 to roll the PET between the two mirror rollers 38 and 39. The film 34 allows the space between the gates to be landfilled. Thereafter, ultraviolet rays of 1 J/m ^{2 were} irradiated with the ultraviolet irradiation device 41, and then taken up by the take-up rolls 42 to obtain the grid sheets 3. Table 1 shows the results of the dimensions, total light transmittance, and viewing angle of each part. The W/H was 0.818, the aperture ratio was 75%, the total light transmittance was 76%, the haze was 14%, and the viewing angle was 60°.

(Mold 3)

‧Dimensions of the groove: Isosceles trapezoid

‧Ditch depth: 110μm

‧Width of the groove: (bottom) 8μm, (top) 20μm

‧itch pitch: 80μm

‧ Size: 100 mm × 100 mm (pattern area).

[Comparative Example 2]

The same applies to Comparative Example 1 except that a grooved mold roll (mold 4) having a cross-sectional shape obtained by reversing the cross-sectional shape of the mold 1 was used instead of the grooved mold roll (mold 3). The way to obtain the grid 4 is obtained. Table 1 shows the results of the dimensions, total light transmittance, and viewing angle of each part. The W/H was 0.200, the aperture ratio was 63%, the total light transmittance was 75%, the haze was 18%, and the viewing angle was 55°.

[Comparative Example 3]

Although it is intended to manufacture the mold 4 having the convex portion having the same shape as the groove of the grid sheet 3, when the cutting mold is performed, the mold cannot be manufactured due to the collapse of the convex portion.

(design shape of mold 4)

‧ Cross-sectional shape of the convex part: Isosceles trapezoid

‧ Height of the convex part: 40μm

‧Width of the convex part: (upper) 3μm, (bottom) 5μm

‧Pitch of the convex part: 35μm

‧ Size: 100 mm × 100 mm (pattern area).

As is apparent from the results of the respective examples, the grid of the present invention maintains the same viewing angle as the grid of the comparative example, but the total light transmittance in the front direction is high and the haze is small. That is, when it is used for a display, it is a grating which has a loss of luminance and a deterioration in image quality. Further, it has also been found that according to the method of manufacturing a grid sheet of the present invention, an extremely small gate portion can be easily produced.

Further, the grid sheets of the present invention (Examples 1, 2, and 3) can be produced regardless of the order of the steps (B) and (C). Further, in the case where the step (B) is performed first, when the hardening of the gate material is performed after the step (C), a grid having a higher total light transmittance and a lower haze can be obtained (according to the embodiment 2 and the implementation) Comparison of Example 3).

Further, it is also known that the grid material is not only a mixture of a resin and a pigment, but also a grid sheet can be produced in the case of only one of a pigment and a dye.

(Examples 4 and 5)

In addition, it is also known that the shape of the portion of the grid that is not filled with the trench gate material is about a trapezoid with the boundary line with the gate portion as the upper bottom (Examples 1, 3, 4, 5), and other In comparison with the examples and the comparative examples, the total light transmittance was high and the haze was small.

The mold shapes of Comparative Example 1 and Comparative Example 2 were the shapes of the grooves.

The shape of the mold of Comparative Example 3 was the shape of the convex portion.

[Industry use possibility]

The present invention is useful in the manufacturing art of a viewing angle control sheet for a display or a screen, a diffusion control sheet, a grid for a comparative improvement sheet, and a grid.

1. . . Grid

2. . . Grooved resin sheet

3. . . Grid

4. . . Surface of the grid

5. . . Pattern mold

6. . . Forming the resin sheet before the groove

8. . . ditch

9. . . Mirror roll 1

10. . . Gate material

11. . . Resin sheet filled with gate material

12. . . Mold

13, 14. . . The boundary between the grid and the side wall of the trench

15. . . a portion of the groove of the resin sheet that is not filled with the gate material

16. . . The boundary line with the grid

17. . . a line connecting the surface of the resin sheet

21~24. . . Warming plate

30. . . Groove mold roll

31. . . ditch

32. . . Resin supply device

33. . . scraper

34. . . PET film

35. . . Roll

36. . . Ultraviolet irradiation device 1

37. . . Return roller

38. . . Mirror roller 2

39. . . Mirror roller 3

40. . . Resin supply device

41. . . Ultraviolet irradiation device 2

42. . . Take-up roll

P. . . Ditch pitch

H. . . Height of the grid

W. . . The widest width of the grid

1(a) to (c) are schematic perspective and schematic cross-sectional views of a grid sheet of the present invention.

Fig. 2 (a) to (d) are schematic views showing the steps of forming a groove on the surface of the resin sheet.

Fig. 3 (a) to (c) are schematic views showing the steps of filling the gate material in the grooved resin sheet.

4(a) to (f) are views showing a step of pressurizing the resin sheet filled with the gate material in the thickness direction to deform the convex portion of the resin sheet.

Fig. 5 is a photograph of a cross section of the grid of Example 3.

Fig. 6 (a) and (b) are schematic views showing a manufacturing apparatus for manufacturing a grid of Comparative Example 1.

Fig. 7 (a) and (b) are schematic cross-sectional views showing the shape of a portion which is not filled with the gate material of the trench, which is about trapezoidal.

Fig. 8 is a schematic enlarged view for explaining the gate portions of p, W, and H.

1. . . Grid

2. . . Grooved resin sheet

3. . . Grid

4. . . Surface of the grid

Claims (8)

A grid sheet comprising: a resin sheet having a plurality of parallel grooves formed on a first surface thereof; and a gate portion formed of a gate material filled at least at a bottom portion of the groove; and The aperture ratio observed in a direction perpendicular to the vertical direction is 80% or more, and the widest width W of the gate portion is 0.1 μm or more and 5 μm or less, and the widest portion of the gate portion is perpendicular to the longitudinal direction of the groove. The ratio W/H of the width W to the height H is 0.01 or more and 0.2 or less, and the shape of the portion of the groove not filled with the gate material is about a trapezoid, wherein the approximately trapezoidal system has a boundary with the boundary of the gate as an upper bottom. . A grid sheet according to claim 1, wherein the resin sheet is composed of a thermoplastic resin. A method for manufacturing a grid, comprising the steps of: forming a resin sheet having a plurality of parallel grooves on one side surface (A); and filling the gate material at least in the step (A) a step (B) of the bottom of the groove; and a step (C) of pressurizing the resin sheet in the thickness direction of the sheet to narrow the width of the groove. A method of producing a grid sheet according to the third aspect of the invention, wherein the resin sheet is composed of a thermoplastic resin. A method of manufacturing a grid sheet according to item 4 of the patent application, wherein the step (A) is a step of melt-extruding a thermoplastic resin to form a resin sheet, and pressing a mold having a convex portion on the surface to the resin sheet to form a shape corresponding to the shape of the convex portion on the resin sheet The step of the ditch. A method of producing a grid sheet according to claim 3 or 4, wherein the step (A) is carried out by extrusion molding of a resin. A method of manufacturing a grid sheet according to claim 3 or 4, wherein the step (C) is carried out after the step (B). A method of manufacturing a grid sheet according to claim 7, wherein the gate material is hardened after the step (C).