JP2008304701A - Uneven pattern formed sheet, its manufacturing method, process sheet original plate for manufacturing light diffusion body, and method for manufacturing light diffusion body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an uneven pattern foamed sheet by which the uneven pattern formed sheet capable of being used as a light diffusion body can simply be manufactured. <P>SOLUTION: The manufacturing method of uneven pattern formed sheet comprises: a process of forming a layered sheet by disposing a hard layer made of a metal or a metal compound, which has a smooth surface and has a thickness of >0.01 μm and ≤0.2 μm, on one surface of a base made of resin; and a process of deforming at least a hard layer of the layered sheet so as to fold the hard layer, wherein the hard layer is constituted with a metal or a metal compound. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a concavo-convex pattern forming sheet used as a process sheet for producing a light diffuser and a method for producing the same. Moreover, it is related with the process sheet | seat original plate for light diffuser manufacture used as a type | mold for manufacturing the light diffuser in which the uneven | corrugated pattern was formed in the surface. Furthermore, it is related with the manufacturing method of a light diffuser.

Generally, a concavo-convex pattern forming sheet having a wave-like concavo-convex pattern formed on the surface is used as a light diffuser.
For example, in Patent Document 1, as a light diffuser, a plurality of protrusions are formed on at least one surface of a light-transmitting substrate, the height of the protrusions is 2 to 20 μm, and the interval between the vertexes of the protrusions is 1 to 10 μm. A projection having an aspect ratio of 1 or more is disclosed. Patent Document 1 discloses a method of processing the surface of a light-transmitting substrate by irradiation with an energy beam such as a KrF excimer laser as a method for forming a protrusion.
Patent Document 2 discloses a diffusion light guide plate (light diffuser) in which an anisotropic diffusion pattern composed of wavy irregularities is formed on one side. In Patent Document 2, as a method for forming an anisotropic diffusion pattern, a photosensitive resin film is irradiated with a laser beam to be exposed and developed to form a master hologram having unevenness formed on one side. A method for transferring the master hologram to a mold and molding a resin using the mold is disclosed.
JP-A-10-123307 Japanese Patent Application Laid-Open No. 2006-261064

  The light diffusers described in Patent Documents 1 and 2 have sufficient light diffusibility. However, the processing method described in Patent Document 1 by irradiation with an energy beam and the method of exposing and developing a photosensitive resin film described in Patent Document 2 with a laser have a problem that they are complicated. Further, the light diffusers of Patent Documents 1 and 2 cannot be said to have sufficient diffusion anisotropy.

  This invention is made | formed in view of the said situation, and it can utilize as a process sheet | seat for manufacturing a light diffuser, and it aims at providing the uneven | corrugated pattern formation sheet which can be manufactured simply. Moreover, it aims at providing the manufacturing method of the uneven | corrugated pattern formation sheet which can manufacture the uneven | corrugated pattern formation sheet utilized as a process sheet | seat for manufacturing a light diffuser simply. Furthermore, there is provided a process sheet for manufacturing a light diffuser and a method for manufacturing the light diffuser, which can easily and in large quantities produce a light diffuser having a concave / convex pattern having the most frequent pitch and average depth equivalent to the concave / convex pattern forming sheet. The purpose is to provide.

The present invention includes the following aspects.
[1] A concavo-convex pattern forming sheet comprising a resin base material and a hard layer provided on one side of the base material, and a concavo-convex pattern formed in one direction on the surface of the hard layer,
The hard layer is made of metal or metal compound,
A concavo-convex pattern forming sheet, wherein the concavo-convex pattern has a mode pitch of more than 1 μm and 20 μm or less, and the average depth of the bottom of the concavo-convex pattern is 10% or more when the mode pitch is 100%.
[2] The uneven pattern forming sheet according to [1], wherein the hard layer is made of metal.
[3] The metal is at least one selected from the group consisting of gold, aluminum, silver, carbon, copper, germanium, indium, magnesium, niobium, palladium, lead, platinum, silicon, tin, titanium, vanadium, zinc, and bismuth. The uneven | corrugated pattern formation sheet as described in [2] which is a metal.
[4] A step of forming a laminated sheet by providing a metal or metal compound hard layer having a smooth surface on one side of a resin base material, and a step of deforming at least the hard layer of the laminated sheet so as to be folded. And
The manufacturing method of the uneven | corrugated pattern formation sheet characterized by the thickness of a hard layer exceeding 0.01 micrometer and 0.2 micrometer or less.
[5] In the step of using a uniaxial heat-shrinkable film as a resin substrate and deforming the hard layer so as to be folded, the laminated sheet is heated to shrink the uniaxial heat-shrinkable film. Manufacturing method of uneven | corrugated pattern formation sheet.
[6] A light diffuser comprising the concavo-convex pattern forming sheet according to any one of [1] to [3], wherein the concavo-convex pattern having the most frequent pitch and average depth equivalent to the concavo-convex pattern forming sheet is formed on the surface. A process sheet original plate for producing a light diffuser used as a mold for producing a sheet.
[7] A step of applying an uncured curable resin to the surface on which the concavo-convex pattern is formed, of the light diffuser manufacturing process sheet original plate according to [6],
A process for producing a light diffuser comprising: curing the curable resin, and then peeling the cured coating film from the process sheet original plate.
[8] The step of bringing a sheet-like thermoplastic resin into contact with the surface on which the concave-convex pattern is formed of the light diffuser production process sheet original plate according to [6],
A step of heating and softening the sheet-like thermoplastic resin while being pressed against the process sheet original plate, and then cooling;
A method for producing a light diffuser comprising: a step of peeling a cooled sheet-like thermoplastic resin from a process sheet original plate.
[9] A step of laminating a concavo-convex pattern transfer material on the surface on which the concavo-convex pattern is formed of the light diffuser production process sheet original plate according to [6],
A step of peeling the concavo-convex pattern transfer material laminated on the concavo-convex pattern from the process sheet original plate to produce a molded product for the secondary process;
A step of coating an uncured curable resin on the surface of the molded product for the secondary process, which is in contact with the uneven pattern of the process sheet original plate;
A method for producing a light diffuser comprising: curing the curable resin, and then peeling the cured coating film from the molded product for the secondary process.
[10] A step of laminating a concavo-convex pattern transfer material on the surface on which the concavo-convex pattern is formed of the light diffuser production process sheet original plate according to [6],
A step of peeling the concavo-convex pattern transfer material laminated on the concavo-convex pattern from the process sheet original plate to produce a molded product for the secondary process;
A step of bringing a sheet-like thermoplastic resin into contact with the surface of the molded product for the secondary process that is in contact with the concave-convex pattern of the process sheet original plate;
A step of heating and softening the sheet-like thermoplastic resin while being pressed against the molded product for the secondary process, and then cooling,
A method for producing a light diffusing body comprising a step of peeling a cooled sheet-like thermoplastic resin from a molded product for a secondary process.

The uneven | corrugated pattern formation sheet of this invention can be utilized as a process sheet | seat for manufacturing a light diffuser, and can be manufactured simply.
According to the manufacturing method of the uneven | corrugated pattern formation sheet of this invention, the uneven | corrugated pattern formation sheet utilized as a process sheet | seat for manufacturing a light diffuser can be manufactured simply.
According to the process sheet for producing a light diffuser and the method for producing a light diffuser of the present invention, a light diffuser in which a concavo-convex pattern having the most frequent pitch and average depth equivalent to that of the concavo-convex pattern forming sheet is formed easily and in large quantities. Can be manufactured.

(Uneven pattern forming sheet)
An embodiment of the uneven pattern forming sheet of the present invention will be described.
In FIG.1 and FIG.2, the uneven | corrugated pattern formation sheet of this embodiment is shown. The uneven | corrugated pattern formation sheet 10 of this embodiment is provided with the base material 11 and the hard layer 12 provided in the single side | surface of the base material 11, and the hard layer 12 has the uneven pattern 12a.

  The concavo-convex pattern 12a of the concavo-convex pattern forming sheet 10 has a wavy unevenness substantially along one direction, and the wavy unevenness meanders. Further, the tip of the convex portion of the concavo-convex pattern 12a of this embodiment is rounded.

  Examples of the resin constituting the substrate 11 include polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, polystyrene resins such as styrene-butadiene block copolymers, polyvinyl chloride, polyvinylidene chloride, and polydimethylsiloxane. And silicone resins, fluororesins, ABS resins, polyamides, acrylic resins, polycarbonates, polycycloolefins, and the like.

  The thickness of the base material 11 is preferably 0.3 to 500 μm. If the thickness of the base material 11 is 0.3 μm or more, the concavo-convex pattern forming sheet 10 is hardly broken, and if it is 500 μm or less, the concavo-convex pattern forming sheet 10 can be easily thinned. Moreover, in order to support the base material 11, you may provide the resin-made support bodies of thickness 5-500 micrometers.

The hard layer 12 is made of a metal or a metal compound. A metal is preferable in that the uneven pattern forming sheet 10 can be easily obtained.
As the metal, the Young's modulus is not excessively high, and the uneven pattern 12a is more easily formed. Therefore, gold, aluminum, silver, carbon, copper, germanium, indium, magnesium, niobium, palladium, lead, platinum, silicon It is preferably at least one metal selected from the group consisting of tin, titanium, vanadium, zinc and bismuth. The metal here includes a semi-metal.
For the same reason, the metal compounds include titanium oxide, aluminum oxide, zinc oxide, magnesium oxide, tin oxide, copper oxide, indium oxide, cadmium oxide, lead oxide, silicon oxide, barium fluoride, calcium fluoride, fluoride. It is preferably at least one metal compound selected from the group consisting of magnesium, zinc sulfide and gallium arsenide.

  When the hard layer 12 is made of metal, the surface of the layer may be air oxidized to form an air oxide film. However, in the present invention, the surface of such a metal layer may be air oxidized. It is considered as a layer made of metal.

The thickness of the hard layer 12 is preferably more than 0.01 μm and not more than 0.2 μm, and more preferably 0.02 to 0.1 μm. If the thickness of the hard layer is more than 0.01 μm and not more than 0.2 μm, an uneven pattern forming sheet can be easily produced as described later.
Further, a primer layer may be formed between the base material 11 and the hard layer 12 for the purpose of improving adhesion and forming a finer structure.

  The most frequent pitch A of the concavo-convex pattern 12a of the concavo-convex pattern forming sheet 10 is more than 1 μm and 20 μm or less, preferably more than 1 μm and 10 μm or less. When the most frequent pitch A is less than 1 μm and more than 20 μm, a light diffuser with high light diffusibility can be obtained even if the concavo-convex pattern forming sheet 10 is used as a process sheet original plate for producing a light diffuser. Becomes difficult.

The average depth B of the bottom 12b of the concavo-convex pattern 12a is 10% or more (that is, the aspect ratio is 0.1 or more) when the most frequent pitch A is 100%, and 30% or more (that is, the aspect ratio is 0.3). Or more). When the average depth B is less than 10% when the most frequent pitch A is 100%, a light diffusing body having high light diffusibility even when the concavo-convex pattern forming sheet 10 is used as a process sheet original plate for manufacturing a light diffusing body. It becomes difficult to get.
In addition, the average depth B is preferably 300% or less (that is, an aspect ratio of 3.0 or less) when the most frequent pitch A is 100% from the viewpoint that the uneven pattern 12a can be easily formed. Is 200% or less (that is, the aspect ratio is 2.0 or less).
Here, the bottom portion 12b is an inflection point of the concave portion of the concave / convex pattern 12a, and the average depth B is obtained when viewing a cross section (see FIG. 2) obtained by cutting the concave / convex pattern forming sheet 10 along the length direction. , The average value (B _AV ) of the lengths B ₁ , B ₂ , B ₃ ... From the reference line L ₁ parallel to the surface direction of the entire concavo-convex pattern forming sheet 10 to the top of each convex portion, and the reference line It is the difference (b _AV −B _AV ) from the average value (b _AV ) of the lengths b ₁ , b ₂ , b ₃ ... From L ₁ to the bottom of each recess. The top part of the convex part and the bottom part of the concave part are in contact with the surface of the hard layer 12 opposite to the substrate 11 side.
As a method of measuring the average depth B, a method of measuring the depth of each bottom by using a cross-sectional image of a concavo-convex pattern photographed by an atomic force microscope and obtaining an average value thereof is employed.

In order to obtain a light diffuser with high light diffusion anisotropy, the uneven pattern 12a meanders to some extent, and the pitch between adjacent convex parts varies along the direction of the uneven pattern 12a. Is preferred. Here, the variation in the orientation of the concavo-convex pattern 12a is referred to as the degree of orientation. The greater the degree of orientation, the more the orientation varies. This degree of orientation is determined by the following method.
First, the top surface of the concavo-convex pattern is photographed with a surface optical microscope, and the image is converted into a grayscale file (for example, a tiff format). In the grayscale file image (see FIG. 3), the lower the whiteness, the deeper the bottom of the concave portion (the higher the whiteness, the higher the top of the convex portion). Next, the image of the grayscale file is Fourier transformed. FIG. 4 shows an image after Fourier transform. The white part extending from the center of the image in FIG. 4 to both sides includes information on the pitch and orientation of the concavo-convex pattern 12a.
Then, pull the extension line L ₂ in the horizontal direction from the center of the image of FIG. 4, plotted (see FIG. 5) the luminance of the auxiliary line. The horizontal axis of the plot of FIG. 5 represents the pitch, the vertical axis represents the frequency, and the value X at which the frequency is maximum represents the most frequent pitch of the concavo-convex pattern 12a.
Then, in FIG. 4, the auxiliary line L ₃ perpendicular at portions of the auxiliary line L ₂ and the value X pull, its plotting the luminance on the auxiliary line L ₃ (see FIG. 6). However, the horizontal axis of FIG. 6 is a numerical value divided by the value of X to enable comparison with various uneven structures. The horizontal axis in FIG. 6 represents an index (orientation) indicating the degree of inclination with respect to the direction of unevenness formation (vertical direction in FIG. 3), and the vertical axis represents frequency. The half width W ₁ of the peak in the plot of FIG. 6 (the width of the peak at the height at which the frequency is half of the maximum value) represents the degree of orientation of the uneven pattern. As the half width W ₁ is larger, indicating that the variations in the pitch meanders.

The degree of orientation is preferably 0.3 to 1.0. If the degree of orientation is 0.3 to 1.0, since the unevenness of the pitch of the concavo-convex pattern 12a is large, the light diffusibility of the light diffuser obtained by using the concavo-convex pattern forming sheet as a process sheet original plate becomes higher. . When the degree of orientation exceeds 1.0, the direction of the concavo-convex pattern becomes random to some extent, so that the light diffusibility increases but the anisotropy tends to decrease.
In order to set the degree of orientation to 0.3 to 1.0, a method of applying a compressive stress necessary for manufacturing the uneven pattern forming sheet may be appropriately selected.

  Note that the most frequent pitch of the concavo-convex pattern obtained using the Fourier transform as described above is equivalent to the average pitch.

Since the uneven | corrugated pattern formation sheet 10 of this invention which the hard layer 12 consists of a metal layer or a metal compound is obtained by the manufacturing method of the uneven | corrugated pattern formation sheet mentioned later, it can be manufactured simply.
Further, as a result of investigation by the inventors, the most frequent pitch A of the concavo-convex pattern 12a is more than 1 μm and not more than 20 μm, and the average depth B of the bottom 12b of the concavo-convex pattern 12a is 10 when the most frequent pitch A is 100%. % Of the concavo-convex pattern forming sheet 10 of the present invention, which is at least%, was found to be usable as a process sheet for producing a light diffuser.

  In addition, the uneven | corrugated pattern formation sheet of this invention is not limited to embodiment mentioned above. For example, the tip of the convex part of the concavo-convex pattern of the concavo-convex pattern forming sheet of the present invention may be sharp. However, it is preferable that the tip of the concavo-convex pattern has a rounded shape because the anisotropy of diffusion becomes higher.

(Method for producing uneven pattern forming sheet)
An embodiment of the method for producing a concavo-convex pattern forming sheet of the present invention will be described.
As shown in FIG. 7, the manufacturing method of the uneven | corrugated pattern formation sheet of this embodiment has the resin-made hard layer 13 (henceforth the surface smooth hard layer 13) with the smooth surface on the single side | surface of the heat-shrinkable film 11a. Forming the laminated sheet 10a (hereinafter referred to as a first step), and a step of causing the heat-shrinkable film 11a to be heated and shrunk to deform at least the surface smooth hard layer 13 of the laminated sheet 10a (see FIG. Hereinafter, it is referred to as a second step).
Here, the smooth surface hard layer 13 is a layer having a center line average roughness of 0.1 μm or less as described in JIS B0601.

[First step]
In the first method, as the method of forming the laminated sheet 10a, for example, a method in which a metal or a metal compound is vapor-deposited on one side of the heat-shrinkable film 11a, or a surface smooth hard material previously produced on one side of the heat-shrinkable film 11a. The method of laminating | stacking the layer 13 etc. are mentioned.

As the heat-shrinkable film 11a, for example, a polyethylene terephthalate shrink film, a polystyrene shrink film, a polyolefin shrink film, a polyvinyl chloride shrink film, or the like can be used.
Among shrink films, those that shrink by 50 to 70% are preferable. If a shrink film that shrinks by 50 to 70% is used, the deformation rate can be 50% or more, the most frequent pitch A of the concavo-convex pattern 12a is more than 1 μm and not more than 20 μm, and the average depth B of the bottom 12b of the concavo-convex pattern 12a is the most frequent pitch. 10% or more of the concavo-convex pattern forming sheet 10 when A is 100% can be easily produced. Furthermore, the uneven | corrugated pattern formation sheet 10 when the average depth B of the bottom part 12b of the uneven | corrugated pattern 12a makes the most frequent pitch A 100% can also be manufactured easily.
Here, the deformation rate is (length before deformation−length after deformation) / (length before deformation) × 100 (%). Alternatively, (deformed length) / (length before deformation) × 100 (%).
Moreover, the average depth B of the uneven | corrugated pattern 12a can be 300% when the most frequent pitch A is set to 100% by the following processes.
A primer resin layer having a glass transition temperature lower than that of the heat-shrinkable film 11a is applied to the heat-shrinkable film 11a, and a laminated sheet in which the surface hard smooth layer 13 is provided on the primer resin layer is formed. The concavo-convex pattern forming sheet is formed by heat shrinking the laminated sheet.
The heat-shrinkable film 11a after heat shrinkage is peeled from the laminated sheet, and another heat-shrinkable film is bonded to form a laminated sheet. By heat-shrinking this laminated sheet, the average depth B can be increased as compared with the case where one heat-shrinkable film is heat-shrinked. By repeating this step a plurality of times, the average depth B of the concavo-convex pattern 12a can be 300% when the most frequent pitch A is 100%.

In this manufacturing method, since the uneven pattern 12a can be more easily formed, the Young's modulus of the surface smooth hard layer 13 is preferably 0.1 to 500 GPa, more preferably 1 to 150 GPa.
In order to set the Young's modulus of the surface smooth hard layer 13 in the above range, the surface smooth hard layer 13 is made of gold, aluminum, silver, carbon, copper, germanium, indium, magnesium, niobium, palladium, lead, platinum, silicon, It is preferably composed of at least one metal selected from the group consisting of tin, titanium, vanadium, zinc, and bismuth. Alternatively, the surface smooth hard layer 13 is made of titanium oxide, aluminum oxide, zinc oxide, magnesium oxide, tin oxide, copper oxide, indium oxide, cadmium oxide, lead oxide, silicon oxide, barium fluoride, calcium fluoride, magnesium fluoride. , Zinc sulfide, and gallium arsenide. It is preferable to use at least one metal compound selected from the group consisting of gallium arsenide.
Here, the Young's modulus is a value measured by changing the temperature to 23 ° C. according to “High Temperature Young's Modulus Test Method for Metal Materials” of JIS Z 2280-1993. The same applies when the hard layer is made of a metal compound.

The thickness of the smooth surface hard layer 13 exceeds 0.01 μm and is 0.2 μm or less, preferably 0.05 to 0.5 μm. By setting the thickness of the surface smooth hard layer 13 in the above range, the most frequent pitch A of the concave-convex pattern 12a can be surely exceeded 1 μm and 20 μm or less. However, if the thickness of the surface smooth hard layer 13 is less than 0.05 μm, the mode pitch A may be 1 μm or less, and if it exceeds 0.5 μm, the mode pitch A may exceed 20 μm.
Moreover, the thickness of the surface smooth hard layer 13 may change continuously. When the thickness of the surface smooth hard layer 13 is continuously changed, the pitch and depth of the uneven pattern 12a formed after compression are continuously changed.

When the laminated sheet 10a is deformed, the surface smooth hard layer 13 is preferably deformed at a deformation rate of 5% or more. If the surface smooth hard layer 13 is deformed at a deformation rate of 5% or more, the average depth B of the bottom 12b of the concavo-convex pattern 12a can be easily made 10% or more when the most frequent pitch A is 100%.
Furthermore, it is more preferable to deform the surface smooth hard layer 13 at a deformation rate of 50% or more. If the surface smooth hard layer 13 is deformed at a deformation rate of 50% or more, the average depth B of the bottom 12b of the concavo-convex pattern 12a can be easily made 100% or more when the most frequent pitch A is 100%.

[Second step]
In the second step, the heat-shrinkable film 11a is thermally shrunk, whereby a wavy uneven pattern 12a is formed on the surface smooth hard layer 13 in a direction perpendicular to the shrinking direction to become the hard layer 12.
Examples of the heating method for heat-shrinking the heat-shrinkable film 11a include a method of passing it through hot air, steam, or hot water. Among them, a method of passing it through hot water is preferable because it can be uniformly shrunk.
The heating temperature when the heat-shrinkable film 11a is heat-shrinked is preferably selected as appropriate according to the type of heat-shrinkable film to be used, the pitch of the target concavo-convex pattern 12a, and the depth of the bottom 12b.

  In this manufacturing method, the thinner the surface smooth hard layer 13 is, the lower the Young's modulus of the surface smooth hard layer 13 is, the smaller the most frequent pitch A of the concavo-convex pattern 12a is, and the higher the deformation rate of the substrate is, The average depth B becomes deeper. Therefore, in order to set the concave / convex pattern 12a to the predetermined mode A and the average depth B, it is necessary to appropriately select the above conditions.

In the manufacturing method of the concavo-convex pattern forming sheet described above, the surface smooth hard layer 13 made of a metal or a metal compound has a Young's modulus that is orders of magnitude greater than that of the heat shrinkable film 11a. When the layer 13 is heat compressed, it becomes folded rather than increased in thickness. Furthermore, since the surface smooth hard layer 13 is laminated | stacked on the heat-shrinkable film 11a, the stress by the shrinkage | contraction of the heat-shrinkable film 11a is applied uniformly to the whole. Therefore, according to the present invention, the surface smooth hard layer 13 is deformed so as to be folded, and the uneven pattern forming sheet 10 having excellent performance as a process sheet for producing a light diffuser can be easily and in a large area. Can be manufactured.
Moreover, according to this manufacturing method, the most frequent pitch A of the concavo-convex pattern 12a is easily set to more than 1 μm and not more than 20 μm, the average depth B of the bottom 12b of the concavo-convex pattern 12a is set to 100%. Can be 10% or more.

(Process diffuser for producing light diffuser and method for producing light diffuser)
The process sheet original plate for manufacturing a light diffuser of the present invention (hereinafter referred to as process sheet original plate) is provided with the above-described uneven pattern forming sheet 10, and the uneven pattern is applied to another material by the method described below. A mold for producing a large number of concavo-convex pattern-forming sheets that can be used as a light diffuser having a concavo-convex pattern having the most frequent pitch and average depth formed on the surface thereof by transferring the concavo-convex pattern to the process sheet original plate. It is used as
The process sheet original plate may further include a resin or metal support for supporting the uneven pattern forming sheet 10.

Specific examples of the method for producing a light diffuser using the process sheet original plate include the following methods (a) to (c).
(A) Step of applying an uncured ionizing radiation curable resin to the surface of the process sheet original plate on which the concavo-convex pattern is formed, and curing the curable resin by irradiating with ionizing radiation and then curing the coating And a step of peeling the film from the process sheet original plate. Here, the ionizing radiation is usually ultraviolet rays or electron beams, but in the present invention, it includes visible rays, X-rays, ion rays and the like.
(B) A step of applying an uncured liquid thermosetting resin to the surface on which the concave and convex pattern of the process sheet original plate is formed, and a coating film cured by heating and curing the liquid thermosetting resin. And a step of peeling from the process sheet original plate.
(C) A step of bringing a sheet-shaped thermoplastic resin into contact with the surface of the process sheet original plate on which the concave / convex pattern is formed, and heating and softening the sheet-shaped thermoplastic resin while pressing the sheet-shaped thermoplastic resin against the process sheet original plate And a step of cooling, and a step of peeling the cooled sheet-like thermoplastic resin from the step sheet precursor.

Moreover, the molded article for secondary processes can be produced using a process sheet | seat original plate, and a light-diffusion body can also be manufactured using the molded article for secondary processes. Examples of the molded product for the secondary process include a secondary process sheet. In addition, as the molded product for the secondary process, there is a plating roll obtained by rolling the process sheet original plate and sticking it on the inside of the cylinder, plating with the roll inserted inside the cylinder, and taking out the roll from the cylinder. It is done.
Specific methods using the molded product for the secondary process include the following methods (d) to (f).

(D) A step of performing metal plating such as nickel on the surface of the process sheet original plate on which the concave / convex pattern is formed, and laminating a plating layer (material for transferring the concave / convex pattern), and peeling the plating layer from the process sheet original plate. Then, a step of producing a metal molded product for the secondary process, and then a step of applying an uncured ionizing radiation curable resin to the surface on the side that has been in contact with the concave-convex pattern of the molded product for the secondary process And a step of irradiating ionizing radiation to cure the curable resin, and then peeling the cured coating film from the molded product for the secondary process.
(E) A step of laminating a plating layer (a material for transferring a concavo-convex pattern) on the surface of the process sheet original plate on which the concavo-convex pattern is formed, and peeling the plating layer from the process sheet original plate for a metal secondary process. The step of producing a molded product, the step of applying an uncured liquid thermosetting resin to the surface that was in contact with the concave-convex pattern of the molded product for the secondary process, and the resin was cured by heating. And a step of peeling the cured coating film from the molded product for the secondary process.
(F) A step of laminating a plating layer (uneven pattern transfer material) on the surface of the process sheet original plate on which the concave / convex pattern is formed, and peeling the plating layer from the process sheet original plate for a metal secondary process A step of producing a molded product, a step of bringing a sheet-shaped thermoplastic resin into contact with the surface of the molded product for the secondary process that has been in contact with the concave-convex pattern, and a secondary process of the sheet-shaped thermoplastic resin. A method comprising: a step of cooling after being softened by heating while pressing the molded product, and a step of peeling the cooled sheet-like thermoplastic resin from the molded product for the secondary process.

  A specific example of the method (a) will be described. As shown in FIG. 8, first, an uncured liquid ionizing radiation curable resin 112 c is applied by a coater 120 to the surface of the web-shaped process sheet original plate 110 on which the uneven pattern 112 a is formed. Next, the process sheet original plate 110 coated with the curable resin is pressed by passing through a roll 130, and the curable resin is filled into the concave and convex pattern 112 a of the process sheet original plate 110. Thereafter, ionizing radiation is irradiated by the ionizing radiation irradiation device 140 to crosslink and cure the curable resin. And the web-like light-diffusion body 150 can be manufactured by peeling the ionizing radiation-curable resin after hardening from the process sheet | seat original plate 110. FIG.

In the method (a), for the purpose of imparting releasability to the surface on which the uneven pattern of the process sheet original plate is formed, before coating with an uncured ionizing radiation curable resin, from a silicone resin, a fluororesin or the like. The layer to be formed may be provided with a thickness of about 1 to 10 nm.
Examples of the coater for applying an uncured ionizing radiation curable resin to the surface of the process sheet original plate on which the uneven pattern is formed include a T-die coater, a roll coater, and a bar coater.
Uncured ionizing radiation curable resins include epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl / acrylate, polyene / acrylate, silicon acrylate, polybutadiene, and polystyrylmethyl methacrylate. Selected from monomers such as prepolymers such as aliphatic acrylate, alicyclic acrylate, aromatic acrylate, hydroxyl group-containing acrylate, allyl group-containing acrylate, glycidyl group-containing acrylate, carboxy group-containing acrylate, halogen-containing acrylate, etc. The thing containing the above component is mentioned. The uncured ionizing radiation curable resin is preferably diluted with a solvent or the like.
Moreover, you may add a fluororesin, a silicone resin, etc. to uncured ionizing radiation curable resin.
When the uncured ionizing radiation curable resin is cured by ultraviolet rays, it is preferable to add a photopolymerization initiator such as acetophenones and benzophenones to the uncured ionizing radiation curable resin.

  After coating the uncured liquid ionizing radiation curable resin, the substrate may be irradiated with ionizing radiation after a substrate made of resin, glass or the like is bonded. Irradiation with ionizing radiation may be performed from any one of the base material and the process sheet original plate having ionizing radiation transparency.

  The thickness of the ionizing radiation curable resin sheet after curing is preferably about 0.1 to 100 μm. If the thickness of the ionizing radiation curable resin sheet after curing is 0.1 μm or more, sufficient strength can be secured, and if it is 100 μm or more, sufficient flexibility can be secured.

In the method shown in FIG. 8, the process sheet original plate is a web-like shape, but it may be a sheet. In the case of using a single sheet, a stamp method using a single sheet as a flat plate mold, a roll imprint method using a single sheet wound around a roll as a cylindrical mold, and the like can be applied. Moreover, you may arrange | position the sheet | seat process sheet | seat original plate inside the type | mold of an injection molding machine.
However, in the method using these single sheets, in order to mass-produce the light diffuser, it is necessary to repeat the process of forming the concavo-convex pattern many times. When the release property between the ionizing radiation curable resin and the process sheet original plate is low, clogging of the concavo-convex pattern occurs when repeated many times, and the transfer of the concavo-convex pattern tends to be incomplete.
On the other hand, in the method shown in FIG. 8, since the process sheet precursor is web-like, it is possible to continuously form a concavo-convex pattern in a large area, so even if the number of repeated use of the concavo-convex pattern forming sheet is small, A required amount of light diffuser can be produced in a short time.

In the methods (b) and (e), examples of the liquid thermosetting resin include uncured melamine resin, urethane resin, and epoxy resin.
Moreover, it is preferable that the curing temperature in the method (b) is lower than the glass transition temperature of the base material constituting the process sheet original plate. This is because if the curing temperature is equal to or higher than the glass transition temperature of the substrate constituting the process sheet original plate, the uneven pattern of the process sheet original plate may be deformed at the time of curing.

In the methods (c) and (f), examples of the thermoplastic resin include acrylic resin, polyolefin, polyester, and the like.
The pressure when pressing the sheet-like thermoplastic resin against the molded product for the secondary process is preferably 1 to 100 MPa. If the pressure at the time of pressing is 1 MPa or more, the concavo-convex pattern can be transferred with high accuracy, and if it is 100 MPa or less, excessive pressurization can be prevented.
Moreover, it is preferable that the heating temperature of the thermoplastic resin in the method (c) is lower than the glass transition temperature of the base material constituting the process sheet original plate. This is because if the heating temperature is equal to or higher than the glass transition temperature of the substrate constituting the process sheet original plate, the uneven pattern of the process sheet original plate may be deformed during heating.
The cooling temperature after heating is preferably less than the glass transition temperature of the thermoplastic resin because the uneven pattern can be transferred with high accuracy.

  Among the methods (a) to (c), the method (a) using an ionizing radiation curable resin is preferable in that heating can be omitted and deformation of the concavo-convex pattern of the process sheet original plate can be prevented.

In the methods (d) to (f), it is preferable that the thickness of the metallic secondary process molded product is about 50 to 500 μm. If the thickness of the metal secondary process molded product is 50 μm or more, the secondary process molded product has sufficient strength, and if it is 500 μm or less, sufficient flexibility can be secured.
In the methods (d) to (f), a metal sheet that is not easily deformed by heat is used as a process sheet. Therefore, as a material for the concavo-convex pattern forming sheet, an ionizing radiation curable resin, a thermosetting resin, or a thermoplastic resin is used. Either can be used.
When using the uneven | corrugated pattern formation sheet manufactured by the method of (a)-(f) as a light diffuser, it consists of the light-diffusion agent which consists of the said inorganic compound, and an organic compound for the purpose of improving a light-diffusion effect more. An organic light diffusing agent or fine bubbles can be contained.

  In addition, in (d)-(f), the uneven | corrugated pattern of the process sheet | seat original plate was transcribe | transferred to the metal, and the molding for secondary processes was obtained, However, you may transcribe | transfer to resin and may obtain the molding for secondary processes. Examples of the resin that can be used in this case include polycarbonate, polyacetal, polysulfone, and ionizing radiation curable resin used in the method (a). When using an ionizing radiation curable resin, similarly to the method (a), the ionizing radiation curable resin is sequentially applied, cured, and peeled to obtain a molded product for the secondary process.

In the light diffuser obtained as described above, an adhesive layer may be provided on the surface opposite to the surface on which the uneven pattern is formed. Moreover, you may form an uneven | corrugated pattern further in the surface on the opposite side to the surface in which the uneven | corrugated pattern was formed.
Moreover, the uneven | corrugated pattern formation sheet used as the process sheet | seat original plate or the molding for secondary processes may be used as a protective layer without peeling, and a protective layer may be peeled off just before use of a light diffusing body.

The light diffusing body manufactured by the manufacturing method described above has the same uneven pattern as the uneven pattern forming sheet 10 described above, and therefore the uneven orientation varies, and the diffusion anisotropy is excellent.
In the light diffuser, another layer may be provided on one side or both sides of the uneven pattern forming sheet. For example, in order to prevent the surface of the concavo-convex pattern forming sheet on the side where the concavo-convex pattern is formed, the antifouling having a thickness of about 1 to 5 nm containing a fluororesin or a silicone resin as a main component is prevented. A layer may be provided.
Further, a transparent resin or glass support may be provided on the surface of the light diffuser where the uneven pattern is not formed.

  The Young's modulus in the following example was changed to 23 ° C. using a tensile tester (Tensilon RTC-1210 manufactured by Orientec Co., Ltd.) according to “High Temperature Young's Modulus Test Method for Metal Materials” in JIS Z 2280-1993. Measured value. The same applies when the hard layer is made of a metal compound.

Example 1
On one side of a heat-shrinkable film made of polyethylene terephthalate with a thickness of 50 μm and a Young's modulus of 3 GPa (Hishipet LX-10S manufactured by Mitsubishi Plastics Co., Ltd.) uniaxially, aluminum with a Young's modulus of 70 GPa is added to a thickness of 0.05 μm. Thus, vacuum deposition was performed to form a surface smooth hard layer to obtain a laminated sheet.
Next, the laminated sheet is heated at 100 ° C. for 1 minute to cause heat shrinkage to 40% of the length before heating (that is, to deform to a deformation rate of 60%), and the hard layer is orthogonal to the shrinking direction. The uneven | corrugated pattern formation sheet which has a wavy uneven | corrugated pattern which has a period along a direction was obtained.
Next, using the uneven pattern forming sheet as a process sheet original plate, a light diffuser was obtained as follows.
That is, an uncured ultraviolet curable resin composition containing an epoxy acrylate prepolymer, 2-ethylhexyl acrylate and a benzophenone photopolymerization initiator was applied to the surface of the process sheet original plate on which the uneven pattern was formed.
Next, a 50 μm-thick triacetyl cellulose film was superimposed on the surface of the uncured ultraviolet curable resin composition coating film that was not in contact with the process sheet original plate and pressed.
Next, ultraviolet light was irradiated from above the triacetyl cellulose film to cure the uncured ultraviolet curable resin, and the cured product was peeled off from the process sheet original plate to obtain a light diffuser.

(Example 2)
Using the uneven pattern forming sheet obtained by the method of Example 1 as a process sheet original plate, a light diffuser was obtained as follows.
That is, the surface of the process sheet original plate obtained in Example 1 on which the concavo-convex pattern was formed was subjected to nickel plating, and the nickel plating was peeled off to obtain a secondary process sheet having a thickness of 200 μm. An uncured ultraviolet curable resin composition containing an epoxy acrylate prepolymer, 2-ethylhexyl acrylate and a benzophenone photopolymerization initiator was applied to the surface of the secondary process sheet on which the uneven pattern was formed.
Next, a 50 μm thick triacetyl cellulose film was superimposed on the surface of the uncured ultraviolet curable resin composition coating film not in contact with the secondary process sheet and pressed.
Next, ultraviolet light was applied from above the triacetyl cellulose film to cure the uncured curable resin, and the cured product was peeled from the secondary process sheet to obtain a light diffuser.

(Example 3)
A light diffusing material was obtained in the same manner as in Example 2 except that a thermosetting epoxy resin was used instead of the ultraviolet curable resin composition, and the thermosetting epoxy resin was cured by heating instead of irradiating with ultraviolet rays. It was.

Example 4
In the same manner as in Example 2, a secondary process sheet having a thickness of 200 μm was obtained. A polyacrylamide film having a thickness of 50 μm was superimposed on the surface of the secondary process sheet on which the uneven pattern was formed, and heated. The polyacrylamide film softened by heating and the secondary process sheet were pressed from both sides, then cooled and solidified, and the solidified polyacrylamide film was peeled from the secondary process sheet to obtain a light diffuser. .

(Comparative Example 1)
A light diffuser was obtained in the same manner as in Example 1 except that aluminum was vacuum-deposited to a thickness of 0.3 μm.

(Comparative Example 2)
A light diffuser was obtained in the same manner as in Example 1 except that aluminum was vacuum-deposited to a thickness of 0.01 μm.

(Comparative Example 3)
Aluminum with a Young's modulus of 70 GPa is 0.05 μm on one side of a heat-shrinkable film made of polyethylene terephthalate with a thickness of 50 μm and a Young's modulus of 3 GPa (Hissippet LX-10S manufactured by Mitsubishi Plastics, Inc.). As described above, vacuum deposition was performed to form a smooth surface hard layer to obtain a laminated sheet.
Next, the laminated sheet was heated at 70 ° C. for 1 minute, and shrunk to 97% of the length before heating (ie, deformed to a deformation rate of 3%). A diffuser was obtained.

(Comparative Example 4)
The uneven | corrugated pattern formation sheet was obtained using the manufacturing method of the anisotropic diffusion pattern shown by patent document 2. FIG.
That is, a shielding plate having a slit having a width of 1 mm and a length of 10 cm, into which a diffusion plate such as polished glass that diffuses and transmits laser light, and a commercially available photosensitive resin were applied in a thickness of 100 μm. The photosensitive film plates were installed so that the distance between them was 1 m and the plates were parallel to each other.
Next, an argon laser having a wavelength of 514 nm was irradiated from the side of the shielding plate, and the photosensitive resin on the photosensitive film plate was exposed with argon laser light that passed through the slit and was diffused by ground glass.
The exposure as described above was repeated to expose the photosensitive resin on the entire surface of the photosensitive film plate. And the exposed photosensitive film was developed and the light diffusing plate was obtained.
FIG. 9 shows a grayscale file converted image in Comparative Example 4, and FIG. 10 shows a Fourier transformed image of the grayscale file image. Further, pulling the auxiliary line L ₄ in the horizontal direction from the center of the image of FIG. 10 shows a diagram plotting the intensity of the auxiliary line in FIG. 11. Further, in FIG. 10, pull the extension line L ₅ perpendicular with portion of the auxiliary line L ₄ and a value Y, shows a diagram plotting the luminance on the extension line L ₅ in FIG. 12.

(Comparative Example 5)
An attempt was made to obtain a light diffuser in the same manner as in Example 1 except that a biaxially stretched polyethylene terephthalate film (G2 manufactured by Teijin Limited) having a thickness of 50 μm and a Young's modulus of 5 GPa was used instead of the shrink film. However, this method cannot form a wavy uneven pattern, and an uneven pattern forming sheet cannot be obtained.

The upper surface of the light diffuser of the uneven | corrugated pattern formation sheet of Examples 1-4 and Comparative Examples 1-5 was image | photographed with the atomic force microscope (Nippon Beeco Nanoscope III).
In the uneven | corrugated pattern formation sheet of Examples 1-4 and Comparative Examples 1-4, the depth of the uneven | corrugated pattern was measured in ten places with the image of the atomic force microscope, and those were averaged and the average depth was calculated | required.
Further, the degree of orientation of the concavo-convex pattern was determined as follows.
First, the top surface of the concavo-convex pattern was photographed with a surface optical microscope, and the image was converted into a grayscale file (see FIG. 3). Next, the image of the grayscale file is Fourier transformed. FIG. 4 shows an image after Fourier transform. Then, pull the extension line L ₂ in the horizontal direction from the center of the image of FIG. 4, and the luminance of the auxiliary line is plotted (see FIG. 5). Then, in FIG. 5, pull the extension line L ₃ perpendicular at portions of the auxiliary line L ₂ and the value X (the modal pitch), the plots the luminance on the auxiliary line L ₃ (see FIG. 6). Then, to determine the degree of orientation of the half-value width W ₁ than the concavo-convex pattern of the peaks in the plot of FIG. ...
These values are shown in Table 1.

Moreover, the suitability as a light diffuser was evaluated according to the following criteria from the most frequent pitch of the concavo-convex pattern and the average depth of the bottom. The evaluation results are shown in Table 1.
○: The mode pitch of the concavo-convex pattern is more than 1 μm and 20 μm or less, the average depth is 10% or more when the mode pitch is 100%, the degree of orientation is 0.3 to 1.0, and as a light diffuser Is suitable.
Δ: The mode pitch of the concavo-convex pattern is 1 μm or less or exceeds 20 μm, or the average depth is less than 10% when the mode pitch is 100%, or the orientation degree is less than 0.3 and light Not necessarily suitable as a diffuser.
×: Uneven pattern cannot be formed

  In Examples 1 to 4 in which the concavo-convex pattern forming sheet obtained by deforming the surface smooth hard layer of the laminated sheet was folded as a process sheet original plate, a light diffuser having a concavo-convex pattern could be easily produced. In particular, in the light diffusers obtained in Examples 1 to 4, the mode pitch of the concavo-convex pattern exceeds 1 μm and is 20 μm or less, and the average depth of the bottom is 10% or more when the mode pitch is 100%. It was suitable as a light diffuser. In Examples 1 to 4, the mode pitch and the average depth as described above were obtained when the thickness of the surface smooth hard layer was more than 0.01 μm and 0.2 μm or less, and the deformation rate was 10% or more. This is because of this.

On the other hand, in Comparative Examples 1 and 2, since the surface hard smooth layer thickness was 0.01 μm or less or more than 0.2 μm, the obtained light diffuser had a concavo-convex pattern having a mode pitch of 1 μm or less or 20 μm. It was over. In Comparative Example 3, since the deformation rate was 3%, the obtained light diffuser had an average depth of the bottom of the concavo-convex pattern of less than 10% when the most frequent pitch was 100%. In Comparative Example 4, the degree of orientation was less than 0.3. These are not necessarily suitable as light diffusers.
On the other hand, in the manufacturing method of Comparative Example 5 using a biaxially stretched polyethylene terephthalate film as the resin base material, the uneven surface pattern was not formed because the surface smooth hard layer was not deformed so as to be folded.

It is an expansion perspective view which expands and shows a part of one embodiment of a concavo-convex pattern formation sheet of the present invention. It is sectional drawing when the uneven | corrugated pattern formation sheet of FIG. 1 is cut | disconnected in the orthogonal direction with the formation direction of an uneven | corrugated pattern. It is a gray scale conversion image of the image obtained by image | photographing the surface of an uneven | corrugated pattern with a surface optical microscope. It is the image which carried out the Fourier transform of the image of FIG. 5 is a graph plotting luminance with respect to the distance from the center of the ring in the image of FIG. 4. Is a graph plotting the luminance on the auxiliary line L ₃ in the image of FIG. It is sectional drawing which shows the lamination sheet in one Embodiment of the manufacturing method of the uneven | corrugated pattern formation sheet of this invention. It is a figure explaining an example of the manufacturing method of the light diffusing body using the uneven | corrugated pattern formation sheet of this invention. It is a gray scale conversion image of the image obtained by image | photographing the surface of the uneven | corrugated pattern in the comparative example 4 with a surface optical microscope. It is the image which carried out the Fourier transform of the image of FIG. It is the graph which plotted the brightness | luminance with respect to the distance from the center of the ring in the image of FIG. Is a graph plotting the luminance on the auxiliary line L ₅ in the image of FIG. 10.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Asperity pattern formation sheet 10a Laminated sheet 11 Base material 11a Heat-shrinkable film 12 Hard layer 12a Asperity pattern 12b Bottom part 13 Hard layer made of resin with smooth surface (surface smooth hard layer)

Claims (10)

A concavo-convex pattern forming sheet comprising a resin base material and a hard layer provided on one side of the base material, and having a concavo-convex pattern formed in one direction on the surface of the hard layer,
The hard layer is made of metal or metal compound,
A concavo-convex pattern forming sheet, wherein the concavo-convex pattern has a mode pitch of more than 1 μm and 20 μm or less, and the average depth of the bottom of the concavo-convex pattern is 10% or more when the mode pitch is 100%.   The uneven | corrugated pattern formation sheet of Claim 1 in which a hard layer consists of a metal.   The metal is at least one metal selected from the group consisting of gold, aluminum, silver, carbon, copper, germanium, indium, magnesium, niobium, palladium, lead, platinum, silicon, tin, titanium, vanadium, zinc, and bismuth. The concavo-convex pattern forming sheet according to claim 2. A step of forming a laminated sheet by providing a metal or metal compound hard layer having a smooth surface and a thickness of more than 0.01 μm and not more than 0.2 μm on one side of a resin substrate; and at least of the laminated sheet A step of deforming the hard layer so as to be folded,
An uneven pattern forming sheet, wherein the hard layer is made of a metal or a metal compound.   The uneven | corrugated pattern formation of Claim 4 which heats a laminated sheet and shrinks a uniaxial heat-shrinkable film in the process of using a uniaxial heat-shrinkable film as a resin-made base material, and deform | transforming so that a hard layer may be folded. Sheet manufacturing method.   It is provided with the uneven | corrugated pattern formation sheet in any one of Claims 1-3, For manufacturing the light diffuser by which the uneven | corrugated pattern of the most frequent pitch and average depth equivalent to this uneven | corrugated pattern formation sheet was formed in the surface A process sheet precursor for producing a light diffuser used as a mold. A step of applying an uncured curable resin to the surface on which the concavo-convex pattern is formed of the light diffusion body manufacturing process sheet original plate according to claim 6;
A process for producing a light diffuser comprising: curing the curable resin, and then peeling the cured coating film from the process sheet original plate. A step of bringing a sheet-like thermoplastic resin into contact with the surface on which the concavo-convex pattern is formed of the light diffusion body manufacturing process sheet original plate according to claim 6;
A step of heating and softening the sheet-like thermoplastic resin while being pressed against the process sheet original plate, and then cooling;
A method for producing a light diffuser comprising: a step of peeling a cooled sheet-like thermoplastic resin from a process sheet original plate. The step of laminating a concavo-convex pattern transfer material on the surface on which the concavo-convex pattern is formed, of the light diffuser manufacturing process sheet original plate according to claim 6;
A step of peeling the concavo-convex pattern transfer material laminated on the concavo-convex pattern from the process sheet original plate to produce a molded product for the secondary process;
A step of coating an uncured curable resin on the surface of the molded product for the secondary process, which is in contact with the uneven pattern of the process sheet original plate;
A method for producing a light diffuser comprising: curing the curable resin, and then peeling the cured coating film from the molded product for the secondary process. The step of laminating a concavo-convex pattern transfer material on the surface on which the concavo-convex pattern is formed, of the light diffuser manufacturing process sheet original plate according to claim 6;
A step of peeling the concavo-convex pattern transfer material laminated on the concavo-convex pattern from the process sheet original plate to produce a molded product for the secondary process;
A step of bringing a sheet-like thermoplastic resin into contact with the surface of the molded product for the secondary process that is in contact with the concave-convex pattern of the process sheet original plate;
A step of heating and softening the sheet-like thermoplastic resin while being pressed against the molded product for the secondary process, and then cooling,
A method for producing a light diffusing body comprising a step of peeling a cooled sheet-like thermoplastic resin from a molded product for a secondary process.

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