JP2013076905A - Roll mold, method for manufacturing roll mold, and method for manufacturing optical sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roll mold capable of enhancing flexibility of an uneven shape to be formed.SOLUTION: In a roll mold (10) for molding an uneven shaped portion of an optical sheet (110) having an uneven shape which includes a cylindrical or columnar substrate (11), a layer (13) to be processed which is stacked on the outer peripheral surface of the substrate and has a groove formed therein, and a surface plated layer (14) which is stacked along the surface of the layer to be processed and is a plated layer having a groove portion (15) and a projection (14) formed therein, a bottom width (A) in the groove portion of the surface plated layer is 10 μm or less.

Description

  The present invention relates to a roll mold used when producing an optical sheet having a fine uneven shape on the surface, a roll mold production method, and an optical sheet production method including the roll mold production method.

  An image display device that emits an image to an observer, such as a plasma television or a liquid crystal display device, has a function of improving the quality of image light from the image light source on the observer side and transmitting it to the observer side. An optical sheet is provided.

  Such an optical sheet is usually formed by laminating a plurality of layers having each function, and one of the layers may include a layer having a fine uneven shape on the surface thereof. is there. For example, an optical sheet (light diffusion sheet) described in Patent Document 1 discloses a configuration in which a plurality of unit lenses each having a fine trapezoidal cross-sectional shape are arranged and a substance different from the unit lens is filled between the unit lenses. ing. According to this, viewing angle control is performed using total reflection by the interface.

  When forming a layer having a fine uneven shape on the surface as described above, a roll mold capable of continuously producing the layer is often used in order to increase productivity. The roll mold is, for example, a cylindrical mold as shown in FIG. 12 of Patent Document 1, and an uneven shape capable of transferring the fine uneven shape is formed on the outer peripheral surface thereof.

  Patent Document 2 discloses an invention in which a plating layer containing fine particles is provided on the surface of a roll mold having an uneven shape on the outer peripheral surface to protect the surface of the roll mold and to retain the fine particles in the plating layer. It is disclosed.

JP 2003-66206 A JP 2010-169879 A

  The uneven shape on the outer peripheral surface of the roll mold is formed by cutting using a cutting tool as a cutting tool. However, such unevenness formed on the surface is very small. Therefore, the cutting tool for that purpose is also thin, and the degree of freedom of the concavo-convex shape that can be formed is small. When trying to form a concavo-convex shape that exceeds the limit, it is difficult to cut a long distance until the bite breaks or does not break. It was.

  Then, this invention makes it a subject to provide the roll metal mold | die which can raise the freedom degree of the uneven | corrugated shape which can be formed. Moreover, the manufacturing method of the said roll metal mold | die and the manufacturing method of the optical sheet by this are provided.

  The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.

  The invention according to claim 1 is a roll mold (10) for forming a concavo-convex shape portion of an optical sheet (110) having a concavo-convex shape, and a cylindrical or columnar base (11) and an outer periphery of the base A processed layer (13) that is laminated on the surface to form a groove, and a surface plated layer that is a plated layer that is laminated along the surface of the processed layer to form the groove (15) and the protrusion (16). 14), and the bottom width (A) of the groove portion of the surface plating layer is 10 μm or less.

  The invention according to claim 2 is characterized in that, in the roll mold (10) according to claim 1, the thickness of the surface plating layer (14) is 1 μm or more.

  The invention according to claim 3 is a method of manufacturing a roll mold (10) for forming a concave-convex shape portion of an optical sheet (110) having a concave-convex shape, wherein the work layer (13) is laminated. A step of rotating the columnar or cylindrical substrate (11) to form a groove in the work layer by the cutting tool (30), and a step of forming a plating layer (14) on the surface of the work layer in which the groove is formed. , And the bottom width of the groove in the groove (15) after forming the plating layer on the surface thereof is 10 μm or less.

  Invention of Claim 4 manufactured the roll metal mold | die (10) with the manufacturing method of Claim 3, and filled the photocuring material into the groove | channel formed in the roll metal mold | die, and was filled. The sheet-shaped member is formed by irradiating the light-curable material with light in a state and curing the photo-curable material, and pressing the sheet-shaped member against the surface of the roll mold and then releasing the mold. And a step of moving the cured photocurable material to the surface of the optical sheet.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to raise the freedom degree of the uneven | corrugated shape which can be formed in an optical sheet. In particular, it becomes possible to have a groove shape thinner than the conventional one.

It is a figure explaining one embodiment, and is an external appearance perspective view of a roll metallic mold. It is a front view of a roll metal mold | die. It is a figure explaining the groove part and protrusion which were formed in the outer peripheral surface of a roll metal mold | die. It is a figure explaining the manufacturing method of a roll metal mold | die. It is the figure which expanded and showed the mode of cutting. It is the figure which showed the shape of the cutting tool roughly. It is a figure explaining formation of a surface plating layer. It is the figure which expanded the cross section of the optical sheet. It is the figure which expanded and showed a part of FIG. 8, and represented the example of the optical path.

  The above-described operation and gain of the present invention will be clarified from embodiments for carrying out the invention described below. Hereinafter, the present invention will be described based on embodiments shown in the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 is a diagram for explaining one embodiment, and is a perspective view schematically showing an appearance of a roll mold 10, and FIG. 2 is a front view thereof. FIG. 3 is an enlarged cross-sectional view of the portion indicated by III in FIG. 2 and shows a cross section of the groove 15 and the protrusion 16 formed on the outer peripheral surface of the roll mold 10. The cross section is a cross section in the direction along the rotation axis of the roll mold 10. Note that the grooves 15 and the protrusions 16 formed on the surface of the roll mold 10 and the unevenness of the optical sheet 110 formed corresponding thereto are very fine, but here for ease of understanding. Exaggerated.

  As can be seen from FIGS. 1 and 2, the roll mold 10 includes a cylindrical mold body 11 and a rotation shaft 20. The rotating shaft 20 is a rotating shaft member with the cylindrical axis of the mold body 11 as an axis. As can be seen from FIGS. 1 to 3, a groove 15 and a convex portion 16 that can transfer the concave-convex shape of the optical sheet to be formed are spirally formed on the outer peripheral surface of the mold body 11. This will be described in detail below.

  As can be seen from FIG. 3, the mold body 11 includes a base 12 that serves as a base, a work layer 13 that is laminated on the outer surface of the base 12, and a surface plating layer 14 that is formed on the outermost surface of the mold body 11. have.

  The base 12 is a part for securing the rigidity of the mold body 11 and occupies most of the mold body 11. From this point of view, the base 12 is preferably made of an iron-based material for mechanical structure. Further, from the viewpoint of reducing the weight while ensuring the necessary rigidity, the base body 12 may have a bottomed cylindrical shape having bottoms at both ends. In addition, a double structure is generally used so that cold water, hot water, steam, or high-temperature oil can be circulated inside the base 12 so that the surface temperature of the roll mold 10 can be adjusted.

  The layer 13 to be processed is a layer laminated so as to cover the outer peripheral surface of the base 12. Since the material of the substrate 12 is selected from the viewpoint of structure as described above, it is often difficult to process. In addition, since it is only necessary to actually process the vicinity of the surface of the mold main body 11, a layer 13 to be processed that is relatively easy to process is provided in the processed portion. Therefore, the layer to be processed 13 is preferably a plated layer made of a material that can be easily processed, such as a layer by copper plating or a layer by nickel plating. The thickness of the layer 13 to be processed is determined by the shape to be processed due to its nature. For example, the thickness of the processed layer 13 after processing is not a problem as long as it is equal to or higher than the required shape, but is usually from 0.3 mm to 1.0 mm.

The surface plating layer 14 is a plating layer that is laminated so as to cover the surface of the processing layer 13 along the unevenness formed in the processing layer 13, and constitutes the outermost layer of the mold body 11. The material for forming the surface plating layer 14 is not particularly limited, but nickel or chromium is preferable from the viewpoint of preventing the surface of the roll mold 10 from corroding.
Further, as described later, the surface plating layer 14 is laminated not only to protect the surface of the roll mold 10 but also to determine the shape of the groove 15 and the shape of the protrusion 16 which will be described later.

  The surface plating layer 14 is preferably formed to be thicker than the conventional surface plating layer from the viewpoint that the shape of the groove 15 and the protrusion 16 can be positively controlled, such as forming the groove 15 to be thin. More specifically, the surface plating layer 14 preferably has a thickness of 1 μm or more. This is because if it is thinner than this, there is a high possibility that the effect of plating cannot be obtained. The upper limit of the thickness of the surface plating layer 14 is not particularly limited, but is preferably 4 μm or less.

In addition, when the width of the bottom surface of the groove 15 shown by A in FIG. 3 is 10 μm or less, the effect of the surface plating layer 14 is particularly remarkable. That is, when forming the groove 15, it is difficult to form the groove with a thin cutting tool having a bottom surface width of 10 μm or less. On the other hand, if the grooves 15 are finally formed by the surface plating layer 14, a thicker cutting tool can be used, and the workability by cutting can be improved.
Accordingly, the width of the bottom surface can be set to 0 μm, and a narrow groove can be appropriately formed.

A groove is formed in the layer 13 to be processed, and the surface plating layer 14 is laminated along the unevenness to form the groove 15 and the protrusion 16. More details are as follows.
As can be seen from FIG. 2, the groove 15 is inclined at an angle α with respect to the axial direction of the cylindrical mold body 11 in the front view of the mold body 11, and the other is from one end side in the axial direction of the mold body 11 It is formed in a spiral shape toward the end side. The protrusions 16 are protrusions formed between the grooves 15 thus formed in a spiral shape. Accordingly, the protrusion 16 is similarly formed in a spiral shape.

  Here, the magnitude of α is not particularly limited as long as it is larger than 0 ° and smaller than 180 °, and is determined by the form of the optical sheet to be manufactured.

  The groove 15 has a shape capable of forming a recess for the light absorbing portion 114 in the optical functional layer 112 of the optical sheet 110 described later. Similarly, the protrusion 16 has a shape capable of forming the light transmitting portion 113 in the optical function layer 112. The shape of the optical functional layer 112 and the method for forming the same will be described later.

  The diameter of the mold body 11 is not particularly limited, but is preferably 300 mm or more and 500 mm or less.

  Next, an example of the method for manufacturing the roll mold 10 will be described.

  First, a roll mold 10 in which a material to be processed layer 13 is laminated on a substrate 12 is prepared, and this is rotated by a rotating shaft 20. As pre-processing for obtaining a reference surface, mirror processing is performed with a predetermined cutting tool (R bite) with a necessary cutting depth and feed. The R bit is a bit having an arcuate tip, and a diamond bit having a radius of curvature of 2 mm to 10 mm is often used. The feed pitch is generally 0.1 mm to 0.2 mm.

  Thereafter, the surface serving as the outer peripheral end surface of the layer to be processed 13 is processed by the cutting tool while rotating the base 12 based on the obtained reference surface. This is performed by a predetermined cutting tool with a necessary cutting depth and feed.

  Next, the process which forms a groove | channel in the to-be-processed layer 13 is performed. FIG. 4 shows the procedure. FIG. 5 shows an enlarged view of the portion indicated by V in FIG. As can be seen from FIGS. 4 and 5, the groove 15 is formed by cutting the outer peripheral surface with a cutting tool 30 and cutting it while rotating the base 12 around the rotation shaft 20 (for example, arrow IVa). At this time, as indicated by IVb in FIG. 4, the groove 15 is formed in a spiral shape by cutting while cutting the cutting tool 30 in a direction along the rotation axis. And between such spiral groove | channels becomes a processus | protrusion, and an unevenness | corrugation is formed in the surface of the to-be-processed layer 13. FIG. Here, the feed of the cutting tool 30 is adjusted so that the groove has an angle α (see FIG. 2) with respect to the axial direction of the cylindrical mold body 11.

  For example, the cutting tool 30 used for cutting has the following shape. A schematic view of a cutting tip 30 which is an example of a cutting tool used is shown in FIG.

  In FIG. 6, the rake face is denoted by reference numeral 31, the front flank face is denoted by reference numeral 32, and the lateral flank face is denoted by reference numeral 33. 6A is a perspective view, FIG. 6B is a view from the rake face 31 side, FIG. 6C is a view from the front flank face 32 side, and FIG. 6D is a side flank face. It is the figure seen from 33 side.

  The main dimensions of the cutting tip 30 are set so that the uneven shape before the surface plating layer 14 is laminated can be formed on the processing layer.

  The bite angles θa1 and θa2, the side clearance angle θb, and the front clearance angle θc shown in FIG. 6 are as follows. The sum of the bite angles θa1 and θa2 is called the apex angle. In FIG. 6 (b), w is the cutting edge width. The apex angle and the bite tip width are appropriately changed according to the shape of the groove to be formed in the layer 13 to be processed.

Here, in particular, the cutting tool tip width w is the narrowest part in the cutting tip 30, is easily broken (notched), and is a part where the wear is severe. Therefore, the larger w is as possible, the better the durability and life of the cutting tip 30 will be. On the other hand, since w determines the width of the bottom surface of the groove, it is determined by the shape of the optical sheet to be manufactured. Therefore, the width w cannot be increased freely.
On the other hand, in the present invention, the final width of the bottom surface of the groove 15 is adjusted by 14 surface plating layers. Therefore, in the present invention, the tip width w of the cutting tip 30 can be made sufficiently larger than the width of the bottom surface of the groove 15. Thereby, it becomes possible to improve the durability of the cutting tool 30 (the cutting tip 30).

Further, the lateral clearance angle θb is preferably 2 degrees or more and 5 degrees or less. By setting the side clearance angle θb to 2 degrees or more, the cutting performance of the cutting tip 30 is improved and the burden on the cutting tip is reduced. Therefore, wear can be reduced, and durability is increased to one cutting tip. Can be processed with high accuracy. Therefore, it is possible to manufacture a roll mold without exchanging the cutting tip or suppressing the number of exchanges. That is, it is possible to improve the manufacturing efficiency and accuracy of the roll mold 10 and to manufacture the uneven shape of the optical sheet as the final product with high accuracy. Further, if the lateral clearance angle θb is larger than 5 degrees, it is necessary to increase the front clearance angle, and there is a concern that the strength of the cutting tip 30 is lowered.
The front clearance angle θc is usually 5 degrees or more and 20 degrees or less in many cases. If the angle is less than 5 degrees, the cutting performance tends to be deteriorated as with the side clearance angle. On the other hand, if it is greater than 20 degrees, the cutting tip tip is not rigid enough to cause chipping or chipping.

  The material of the cutting tip 30 can be appropriately selected depending on the material of the layer to be processed, the processing shape, and the like. Examples thereof include cemented carbide, CBN (cubic boron nitride), diamond and the like. Among these, diamond is preferable from the viewpoint of obtaining high accuracy. There are natural and synthetic diamonds, but there is no particular limitation.

  Although the rotational speed of the base | substrate 12 at the time of cutting is not specifically limited, It is preferable that they are 300 rpm or more and 600 rpm or less. Although depending on the diameter of the substrate 12, for example, when the diameter is 400 mm, if it is less than 300 rpm, the cutting speed is slow, so that the burden on the cutting tip becomes large and it may not be possible to process with high accuracy. 600 rpm is approximately the maximum turning speed of the lathe. As the rotational speed of the substrate 12 is increased, the substrate 12 tends to be shaken, and from this viewpoint, about 400 rpm is preferable.

  Next, the surface plating layer 14 is formed on the surface of the processing layer 13 on which the uneven pattern is formed as described above. This is schematically shown in FIG. FIG. 7A shows a cross section of the layer 13 to be processed before the surface plating layer 14 is formed, and FIG. 7B shows a case in which the surface plating layer 14 is laminated along the irregular shape of the layer 13 to be processed. 15 represents a cross section in which the protrusion 15 and the protrusion 16 are formed.

  The method for laminating the surface plating layer 14 is not particularly limited, and a known method can be used. Therefore, the surface plating layer 14 can be formed as follows, for example.

  The surface plating layer 14 is formed by sequentially immersing the substrate 12 including the layer 13 to be processed on which the uneven pattern is formed as described above in each bath included in the plating apparatus. Examples of the tanks include a pretreatment tank that performs washing, degreasing, and acid activation treatment, a plating tank that performs plating, and a post-treatment tank that performs washing and drying after plating. Can do.

  A plating solution is stored in the plating tank, and an electrode is also provided. In the plating treatment tank, the substrate 12 is immersed in the plating solution while being energized by the electrodes. At this time, the base 12 is rotated about the rotary shaft 20. Thereby, the surface plating layer 14 is formed.

According to the roll mold and the roll mold manufacturing method as described above, it is possible to obtain a roll mold capable of forming an optical sheet including a layer having an uneven shape.
In the present invention, since the groove shape to be provided in the roll mold is adjusted by the surface plating layer, it is possible to form a narrow groove with high accuracy. It has become possible to form grooves that could not be formed only by cutting as in the prior art.
In addition, when forming a narrow groove, a thick cutting tool can be used for the groove, and the tool life can be improved.

  Next, the manufacturing method of the optical sheet 110 using the said roll metal mold | die 10, and the example of the optical sheet 110 manufactured by this are demonstrated. Here, for ease of understanding, the configuration of the optical sheet 110 to be manufactured will be described first, and then a method for manufacturing the optical sheet 110 using the roll mold 10 will be described.

  FIG. 8 is a cross-sectional view in the thickness direction of the optical sheet 110. FIG. 9 is a partially enlarged view of FIG. 8 and illustrates optical path examples L1 to L4. The optical sheet 110 has a cross section and is formed in a sheet shape so as to extend in the back / front direction of the drawing. The optical sheet 110 has a base material layer 111 and an optical functional layer 112 formed on the base material layer 111. The base material layer 111 and the optical function layer 112 will be described below.

  The base material layer 111 is a layer that becomes a base material for forming the optical functional layer 112 described in detail later. The base material layer 111 is preferably composed of a material mainly composed of polyethylene terephthalate (PET). When the base material layer 111 has PET as a main component, the base material layer 111 may contain other resins. Various additives may be added as appropriate. Examples of general additives include phenol-based antioxidants, lactone-based stabilizers, and the like. Here, “main component” means that the PET is contained in an amount of 50% by mass or more with respect to the entire material forming the base material layer (hereinafter the same).

However, the main component of the material constituting the base material layer 111 is not necessarily PET, and may be other materials. Examples thereof include polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, polyester resins such as terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, and polyamide resins such as nylon 6. , Polyolefin resins such as polypropylene and polymethylpentene, acrylic resins such as polymethyl methacrylate, styrene resins such as polystyrene and styrene-acrylonitrile copolymer, cellulose resins such as triacetyl cellulose, imide resins and polycarbonate resins Etc. Moreover, you may add additives, such as a ultraviolet absorber, a filler, a plasticizer, an antistatic agent, suitably in these resin as needed.
In addition to performance, from the viewpoints of mass productivity, price, availability, etc., it is preferable that the base material layer 111 is made of a resin mainly composed of PET.

  The optical functional layer 112 is a layer that controls the optical path of the image light from the image light source side and has a function of appropriately absorbing stray light and external light. As shown in FIG. 8, the optical function layer 112 includes a light transmission portion 113 and a light absorption portion 114.

  As can be seen from FIG. 8, the light transmitting portions 113 and the light absorbing portions 114 are alternately arranged along the layer surface direction of the optical function layer 112. The cross-sectional shapes of the light absorbing portion 113 and the light absorbing portion 114 correspond to the concavo-convex shape formed by the grooves 15 and the protrusions 16 formed in the roll mold 10 described above, and are transferred shapes. That is, the groove 15 corresponds to the shape of the light absorbing portion 114, and the protrusion 16 corresponds to the shape that forms the light transmitting portion 113.

  Further, as can be seen from FIG. 8, the interface formed by the light transmitting portion 113 and the light absorbing portion 114 may be inclined at a predetermined angle with respect to the normal to the sheet surface represented by the arrow VIII in FIG. As will be described later (see, for example, the light L2 in FIG. 9), the degree of viewing angle control of the emitted image light is determined by this inclination angle. Accordingly, in this case, the corresponding portions (grooves 15 and protrusions 16) formed on the roll mold 10 are inclined according to the inclination of the interface.

Here, in this embodiment, the light absorption part 114 has light absorption performance by containing the light absorption particles 116. That is, the binder 115 (light absorption part constituent composition) in which the light absorption particles 116 are dispersed is filled between the light transmission parts 113. Thereby, the light absorption part 114 can absorb light. The means for absorbing light is not limited to the method using light absorbing particles as in this embodiment. In addition, for example, the entire light absorbing portion can be colored with a pigment or a dye.
The material and method for forming the light absorbing portion 114 will be described in detail later.

  On the other hand, the light transmitting portion 113 is made of a material that transmits light. The material and method for forming the light transmission portion 113 will be described in detail later.

  Here, the light absorbing portion 114 is made of a predetermined material having a refractive index Nb that is the same as or smaller than the refractive index Np of the light transmitting portion 113. In this embodiment, the binder is a substance having a refractive index Nb. The values of the refractive indexes Np and Nb are not particularly limited, but are preferably 1.49 to 1.56 from the viewpoint of availability of applied materials.

  The optical sheet 110 having such an optical functional layer 112 has the following optical effects. FIG. 9 shows optical path examples L1 to L4. However, these optical path examples are conceptual for explaining the optical path and do not accurately represent the degree of refraction or reflection. Further, the optical path example assumes a case where the optical sheet 110 is provided with an image source such as a liquid crystal panel or a plasma display panel below the paper surface of FIG. 9 and image light is provided to an observer present above the paper surface. .

The light L1 is provided to the viewer as it is after the image light emitted from the image source passes through the light transmitting portion 113.
When the refractive index Np of the light transmission unit 113 and the refractive index Nb of the light absorption unit 114 satisfy Np> Nb, the light L2 is emitted from the video source as the light absorption unit 114 and the light transmission unit 113. And is provided to the viewer side after being reflected at the interface. Whether or not the light is reflected at the interface depends on a difference in refractive index between Np and Nb and an incident angle to the interface. As described above, the light L2 is image light provided to the observer in addition to the light L1, so that a brighter image can be provided to the observer. Further, since the interface is configured to have a predetermined inclination angle with respect to the normal to the sheet surface (line indicated by IX in FIG. 9), the image light can be obtained by setting the inclination angle to an appropriate angle. The viewing angle can be controlled.

In the light L <b> 3, the image light emitted from the image source passes through the interface between the light absorption unit 114 and the light transmission unit 113 and is absorbed by the light absorption particles 116 in the light absorption unit 114. Such light is called stray light and is not image light that should be emitted to the observer. Therefore, the quality of the image light can be improved by being absorbed by the light absorbing unit 114.
The light L4 is external light that has entered the optical sheet 110 from the observer side, and is incident on the light absorption unit 114 and absorbed without being reflected at the interface between the light absorption unit 114 and the light transmission unit 113. This improves the contrast and improves the quality of the video.

Next, a method for manufacturing such an optical sheet 110 will be described.
First, an excessive amount of a composition for forming a light absorbing portion on the surface of the roll mold 10 is supplied, and the excess composition is scraped off with a blade. Thereby, the composition constituting the light absorbing portion is filled in the groove 15 of the roll mold 10. Thereafter, the composition filled in the groove 15 is cured by irradiating light or the like.

  Although what is used as a binder among the compositions which comprise a light absorption part is not specifically limited, For example, a reactive dilution monomer (M2) and a photoinitiator (S2) are added to a photocurable prepolymer (P2). ) Is preferably used.

  Examples of the photocurable prepolymer (P2) include urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, and butadiene (meth) acrylate.

  Moreover, as a reactive dilution monomer (M2), a vinyl monomer, a (meth) acrylic acid ester monomer, and a (meth) acrylamide derivative are mentioned as a monofunctional monomer, for example. Moreover, (meth) acrylate type thing is mentioned as a polyfunctional monomer.

  Examples of the photopolymerization initiator (S2) include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1 -One, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and the like. Among these, the irradiation device for curing the photocurable resin composition and the curability of the photocurable resin composition can be arbitrarily selected.

  The light absorbing particles 116 are preferably light absorbing colored particles such as carbon black, but are not limited thereto, and are colored particles that selectively absorb a specific wavelength in accordance with the characteristics of image light. May be used. Specific examples include organic fine particles colored with metal salts such as carbon black, graphite, and black iron oxide, dyes, pigments, colored glass beads, and the like. In particular, colored organic fine particles are preferably used from the viewpoints of cost, quality, availability, and the like. More specifically, acrylic cross-linked fine particles containing carbon black, urethane cross-linked fine particles containing carbon black, and the like are preferably used.

  Next, the base material sheet used as the base material layer which apply | coated the primer on the surface is pressed and made to contact with the outer periphery of the said mold roll, and it is made to peel. Thereby, the hardened composition filled in the groove 15 of the roll mold 10 is detached from the mold roll 10 and moves so as to stand up in the form of a base sheet. Therefore, it is possible to obtain an intermediate member in which a plurality of light absorbing portions are arranged in parallel at a predetermined interval on one surface of the base sheet.

  Next, the intermediate member is supplied between two rolls having a predetermined interval. At this time, the composition which comprises a light transmissive part is supplied between the surface by which the light absorption part is standing among the surfaces of a base material sheet, and a roll. Thereby, the composition which comprises a light transmissive part is filled between light absorption parts, and it can comprise the cross-sectional shape similar to FIG. Thereafter, the composition constituting the light transmission part is cured by irradiating light or the like, and peeled off from the roll.

  Here, as a composition which comprises a light transmissive part, the photocurable resin composition which mix | blended the reactive dilution monomer (M1) and the photoinitiator (S1) with the photocurable prepolymer (P1), for example. Is preferably used.

  Examples of the photocurable prepolymer (P1) include epoxy acrylate-based, urethane acrylate-based, polyether acrylate-based, polyester acrylate-based, and polythiol-based prepolymers.

  Examples of the reactive dilution monomer (M1) include vinyl pyrrolidone, 2-ethylhexyl acrylate, β-hydroxy acrylate, and tetrahydrofurfuryl acrylate.

  Examples of the photopolymerization initiator (S1) include hydroxybenzoyl compounds (2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin alkyl ether, etc.), benzoyl Formate compounds (such as methylbenzoylformate), thioxanthone compounds (such as isopropylthioxanthone), benzophenones (such as benzophenone), phosphate compounds (1,3,5-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-) Trimethylbenzoyl) -phenylphosphine oxide and the like, and benzyldimethyl ketal and the like. Among these, the irradiation device for curing the photocurable resin composition and the curability of the photocurable resin composition can be arbitrarily selected.

  As described above, the optical sheet 110 can be obtained by forming the light transmitting portion 113 and the light absorbing portion 114 on the base material layer 111. At that time, by using the roll mold 10 described above, the optical sheet 110 having the light absorbing portion 114 corresponding to the groove of the roll mold can be obtained.

  The optical sheet 110 may be further laminated with layers having other functions as necessary. Specifically, for example, an electromagnetic wave shielding layer, a wavelength filter layer, an antiglare layer, an antireflection layer, a hard coat layer, and the like can be formed by bonding using an adhesive layer. The order of lamination of these layers and the number of laminations are appropriately determined according to the use of the optical sheet. Although any known layer can be applied to each layer, each layer will be described below.

  The electromagnetic wave shielding layer is a layer having a function of shielding electromagnetic waves. As long as the layer has the function, a means for blocking electromagnetic waves is not particularly limited. Examples thereof include a metal mesh formed by a method such as an etching method, a printing method, a vapor deposition method, or a sputtering method.

  The wavelength filter layer is a layer having a function of attenuating and transmitting light of a predetermined wavelength. The light of the wavelength to be attenuated can be selected as needed, but the layer that attenuates / blocks the neon line emitted from the plasma display panel (PDP), attenuates / blocks infrared rays, near infrared rays, and ultraviolet rays. And a layer for correcting a color tone.

  The antiglare layer is a layer having a function of suppressing so-called glare and is sometimes called an antiglare layer or an AG layer.

  The antireflection layer is a layer that is disposed closest to the viewer and has a function of preventing reflection of external light. According to this, it can suppress that external light reflects on the observer side surface of an optical sheet, returns to the observer side, and what is called reflection arises and it becomes difficult to see an image | video.

  The hard coat layer is sometimes called a protective layer or an HC layer. This is a layer in which a film having a function capable of imparting scratch resistance is provided in order to prevent the image display surface from being scratched.

  The adhesive layer is a layer in which an adhesive is disposed. An acrylic adhesive can be mentioned as this adhesive. However, the pressure-sensitive adhesive is not limited to this as long as necessary light transmittance, adhesiveness, and weather resistance can be obtained. Depending on the layer structure, it is desirable to include a UV absorber (benzotriazole type or the like) having an effect of absorbing ultraviolet rays in the pressure-sensitive adhesive in order to prevent deterioration of the pigment. Moreover, a UV absorber, a near-infrared absorber, a neon ray absorber, and a toning pigment may be included in the adhesive layer in the adhesive layer.

(Example)
In the embodiment, a groove width is formed at a depth of 50 μm and a pitch of 31 μm in a processed layer formed by copper plating with a diamond cutting tool having a tip width indicated by w in FIG. did. Thereafter, a nickel surface plating layer having a thickness of 1.5 μm was formed on the layer to be processed. The surface plating layer was formed by electrolytic nickel plating at a current of 10 A for 1 hour. The roll mold has a diameter of 300 mm and an axial length of 600 mm.
As a result, a groove having a width of 2 μm at the bottom of the groove indicated by A in FIG. 3 and a depth of 48.5 μm could be formed.

  If an attempt is made to form a groove having a width of 2 μm at the bottom of the groove only by cutting with a cutting tool as in the prior art, the cutting tool is broken and the groove cannot be formed appropriately.

DESCRIPTION OF SYMBOLS 10 Roll metal mold 11 Metal mold body 12 Base body 13 Work layer 14 Surface plating layer 15 Groove 16 Projection 20 Rotating shaft 30 Cutting tool 110 Optical sheet

Claims (4)

A roll mold for molding the uneven portion of the optical sheet having an uneven shape,
A cylindrical or columnar substrate;
A layer to be processed that is laminated on the outer peripheral surface of the base body to form a groove;
A surface plating layer that is a plating layer laminated along the surface of the layer to be processed to form a groove and a protrusion, and
The roll metal mold | die whose bottom width of the said groove part of the said surface plating layer is 10 micrometers or less.   The roll mold according to claim 1, wherein the surface plating layer has a thickness of 1 μm or more. A method of manufacturing a roll mold for molding the uneven portion of the optical sheet having an uneven shape,
A step of rotating a columnar or cylindrical substrate on which the layer to be processed is laminated, and forming a groove in the layer to be processed by a cutting tool;
Forming a plating layer on the surface of the layer to be processed in which the groove is formed,
The manufacturing method of a roll metal mold | die whose bottom width of the groove | channel in the groove | channel after forming a plating layer on the said surface is 10 micrometers or less. A roll mold is manufactured by the manufacturing method according to claim 3,
Filling a groove formed in the roll mold with a photocurable material;
Irradiating the photocurable material with light in the filled state to cure the photocurable material; and
A step of moving the cured photocurable material to the surface of the sheet-like member by releasing the mold after pressing and contacting the sheet-like member to the surface of the roll mold. Manufacturing method.

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