JP2013076829A - Optical sheet and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical sheet that is excellent in finish and has hardly any defect such as deformation by reducing adhesion of an adhesive agent to a blade surface of a cutting blade and an occurrence of a defect resulting from the adhesion thereof, and further to provide a manufacturing method of the optical sheet.SOLUTION: An optical sheet 1 formed in a rectangular shape, as viewed in a plan view, with a protecting layer 11 and a coating layer 15 disposed at outermost layers is constituted of layers laminated in an integrated manner of: the protecting layer 11; a base material layer 12; an optical functional layer 13 that has a plurality of light transmitting portions 16 disposed side by side along a surface of the base material layer 12 and light absorbing portions 17 formed among the plurality of light transmitting portions 16; an adhesive agent layer 14; and the coating layer 15 for detachably coating the adhesive agent layer 14. The optical sheet 1 is formed in a substantially trapezoidal shape in a cross-section in a thickness direction D3 such that a width thereof at the protecting layer 11 side is smallest and the width is gradually increased toward the coating layer 15 side.

Description

  The present invention relates to an optical sheet formed in a rectangular shape in plan view, and a method for manufacturing the optical sheet.

  Video display devices that emit images to the viewer, such as liquid crystal displays, plasma displays, rear projection displays, organic EL displays, field emission displays, etc., improve the quality of the video source and the video light from the video source. And an optical sheet having layers having various functions for emitting to an observer.

  Examples of the optical sheet include a base material layer, an optical functional layer, and an adhesive layer for bonding the optical sheet to the surface of a display panel or the like. Such an optical sheet further includes a protective layer for protecting the base material layer and a coating layer for releasably covering the pressure-sensitive adhesive layer. The optical sheet is formed by cutting each of these layers integrally and cutting the protective layer and the coating layer on the outermost side into a rectangular shape in a plan view.

  Such an optical sheet is roughly divided into an optical sheet in which a protective layer is disposed on the base layer side, and an adhesive layer and a coating layer are disposed on the optical functional layer side in the thickness direction, In the direction, there is an optical sheet in which a protective layer is disposed on the optical functional layer side, and an adhesive layer and a coating layer are disposed on the base material layer side.

  In the case of any of the optical sheets described above, conventionally, the width of the protective layer side and the width of the coating layer side are the same by cutting the laminated sheet from the protective layer side to the coating layer side. As shown, the cross section in the thickness direction is cut into a regular square shape. That is, the cut surface is formed at right angles to the surfaces of the protective layer and the coating layer (see Patent Documents 1 and 2).

JP 2006-189867 A JP 2009-198588 A

  As described above, the conventional optical sheet formed in a square shape in the cross section in the thickness direction is cut when the cutting blade is moved from the protective layer side to the coating layer side in the manufacturing process. Since the blade surface of the blade moves in contact with the pressure-sensitive adhesive layer, the pressure-sensitive adhesive easily adheres to the blade surface. Also, when the cutting blade is removed from the sheet in the reverse direction and moved after cutting the sheet, the blade surface of the cutting blade moves while being rubbed against the cutting surface of the sheet, so that more adhesive is attached to the blade surface. It becomes difficult to move in the pulling direction. Furthermore, when the cutting blade is pulled out of the protective layer, the protective layer is easily pulled off from the base material layer or the optical functional layer by the adhesive attached to the blade surface in the pulling direction of the cutting blade.

  As a result, the cut surface of the optical sheet is not finished cleanly, and the adhesive attached to the blade surface is transferred to and attached to the cut surface of the layer other than the adhesive layer, thereby easily reducing the product value of the optical sheet. . Furthermore, when an optical sheet is continuously manufactured due to adhesion of the adhesive to the blade surface of the cutting blade, there is a problem that defects such as cutting failure of the sheet and deformation of the optical sheet are likely to occur.

  The present invention relates to an optical sheet that has a good finish and is less susceptible to deformation and the like, and a method for manufacturing the optical sheet, by reducing the occurrence of problems associated with the adhesion of the cutting blade to the blade surface and the accompanying defects. The issue is to provide.

In order to solve the above problems, the present invention employs the following means.
The invention according to claim 1 is a protective layer (11), a base material layer (12), a plurality of light transmission portions (16) arranged in parallel along the surface of the base material layer (12), and the light transmission. An optical functional layer (13) having a light absorption part (17) formed between the parts (16), an adhesive layer (14), and a coating layer (a) covering the adhesive layer (14) in a peelable manner. 15), and the protective layer (11) and the covering layer (15) are formed in a rectangular shape in a plan view in which the protective layer (11) and the covering layer (15) are arranged on the outermost layer, It is formed in a substantially trapezoidal shape in the cross section in the thickness direction (D3) so that the width on the layer (11) side is the smallest and the width gradually increases toward the coating layer (15) side. It is an optical sheet (1).

  According to a second aspect of the present invention, in the optical sheet of the first aspect, in the thickness direction (D3), the protective layer (11) is disposed on the base layer (12) side, and the adhesive The agent layer (14) and the coating layer (15) are the optical sheet (1) disposed on the optical functional layer (13) side.

  According to a third aspect of the present invention, in the optical sheet of the first aspect, in the thickness direction (D3), the protective layer (11) is disposed on the optical functional layer (13) side, and the adhesive sheet The agent layer (14) and the coating layer (15) are the optical sheet (1) disposed on the base material layer (12) side.

  The invention according to claim 4 is a protective layer (11), a base material layer (12), a plurality of light transmission portions (16) arranged in parallel along the surface of the base material layer (12), and the light transmission. An optical functional layer (13) having a light absorption part (17) formed between the parts (16), an adhesive layer (14), and a coating layer (a) covering the adhesive layer (14) in a peelable manner. 15) and a laminated sheet producing step (S10) for producing a laminated sheet (10) in which the protective layer (11) and the covering layer (15) are arranged in the outermost layer, and the laminated sheet. (10) By moving the cutting blade (20) from the protective layer (11) side to the covering layer (15) side, the width of the protective layer (11) side is the largest. The thickness direction (in order to be small and gradually increase toward the coating layer (15) side. In section 3) an optical sheet cutting step for cutting the rectangular optical sheet (1) in a plan view a substantially trapezoidal shape (S30), a method for producing an optical sheet having.

  The invention according to claim 5 is the method for manufacturing an optical sheet according to claim 4, wherein the laminated sheet is formed after the laminated sheet manufacturing step (S10) and before the optical sheet cutting step (S30). It is a manufacturing method of the optical sheet further provided with the sheet roll preparation process (S20) which winds (10) in roll shape and produces a sheet roll (30).

  Invention of Claim 6 is a manufacturing method of the optical sheet of Claim 4 or 5, In the said lamination sheet preparation process (S10), the said protective layer (11) is the said base material layer (12). The pressure-sensitive adhesive layer (14) and the coating layer (15) are disposed on the side, and the optical sheet is disposed on the optical functional layer (13) side.

  Invention of Claim 7 is a manufacturing method of the optical sheet of Claim 4 or 5, In the said lamination sheet preparation process (S10), the said protective layer (11) is the said optical function layer (13). The pressure-sensitive adhesive layer (14) and the coating layer (15) are disposed on the side, and the optical sheet is disposed on the base layer (12) side.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive is attached to the blade surface of a cutting blade, generation | occurrence | production of the malfunction accompanying it is reduced, the finish is good and there are few malfunctions, such as a deformation | transformation, and manufacture of an optical sheet A method can be provided.

It is a longitudinal cross-sectional view which follows the width direction of the optical sheet which concerns on 1st Embodiment. It is a top view of the optical sheet shown in FIG. It is sectional drawing which expands and shows a part of optical function layer of the optical sheet shown in FIG. 1 roughly. It is a figure which shows the lamination sheet preparation process of the manufacturing method of the optical sheet which concerns on 1st Embodiment, Comprising: (a) is a 1st process, (b) is a 2nd process, (c) is sectional drawing which shows a 3rd process. It is. It is a perspective view which shows roughly the sheet roll preparation process of the manufacturing method of the optical sheet which concerns on 1st Embodiment. It is a top view which shows the example of the arrangement | positioning relationship of the optical sheet with respect to a lamination sheet. It is sectional drawing which expands and shows the principal part of a cutting device. It is an expanded sectional view of the principal part which shows the optical sheet cutting process process of the manufacturing method of the optical sheet which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which follows the width direction of the optical sheet which concerns on 2nd Embodiment. It is a top view which shows another example of arrangement | positioning relationship of the optical sheet with respect to a lamination sheet.

  The above-mentioned operation and effect of the present invention will be clarified from the embodiments for carrying out the invention described below. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments. The drawings are simplified as appropriate for convenience of illustration and easy understanding. Moreover, in each drawing, the same code | symbol is attached | subjected to the same structure, and the code | symbol which becomes repeated may be abbreviate | omitted in some cases.

(First embodiment)
A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view along the width direction of the optical sheet according to the first embodiment. FIG. 2 is a plan view of the optical sheet shown in FIG. FIG. 3 is a cross-sectional view schematically showing a part of the optical functional layer of the optical sheet shown in FIG.
In the description of the optical sheet 1, the direction in which the light transmitting portion 16 and the light absorbing portion 17 of the optical functional layer 13 that will be described in detail later is referred to as “extending direction D <b> 1”. A direction perpendicular to the extending direction D1 and in which the light transmitting portion 16 and the light absorbing portion 17 are arranged in parallel is referred to as a “width direction D2”. The direction perpendicular to the extending direction D1 and the width direction D2 and the thickness direction of the optical sheet 1 is referred to as “thickness direction D3”.

  An image display device (not shown) for emitting an image to an observer includes an image source (not shown) and layers having various functions for improving the quality of image light from the image source and emitting the image light to the observer. The optical sheet 1 is provided. The optical sheet 1 of the first embodiment is bonded to the surface of a display panel or the like using the adhesive force of the adhesive layer 14 in a state where the covering layer 15 and the protective layer 11 are peeled off. As shown in FIG. 1, the optical sheet 1 of 1st Embodiment is the state before joining (state before peeling the coating layer 15 and the protective layer 11), and the protective layer 11 and base material layer in thickness direction D3. 12, the optical functional layer 13, the pressure-sensitive adhesive layer 14, and the coating layer 15 are arranged in this order, and are integrally laminated. The optical sheet 1 has the smallest width W1 on the protective layer 11 side and the largest width W2 on the coating layer 15 side, that is, the width gradually increases from the protective layer 11 side toward the coating layer 15 side. In the cross section in the thickness direction D3, it is formed in a substantially trapezoidal shape.

  The oblique sides 1a, 1a on both sides of the short side direction (width direction) D2 of the optical sheet 1 are such that the angle θ1 formed with the surface of the protective layer 11 is more than 90 ° and not more than 100 °, and the surface of the coating layer 15 Is inclined so that the angle θ2 formed by the above becomes 80 ° or more and less than 90 °.

FIG. 1 shows a cross section in the thickness direction D3 along the short side direction (width direction) D2 of the rectangular optical sheet 1 in plan view, but the optical sheet 1 has its long side direction (extension). Also in the cross section of the thickness direction D3 along the direction D1, it is formed in a substantially trapezoidal shape so that the width gradually increases from the protective layer 11 side toward the coating layer 15 side. The oblique sides 1b and 1b (see FIG. 2) on both sides of the long side direction (extending direction) D1 of the optical sheet 1 are also inclined at the same angle as the oblique sides 1a and 1a on both sides of the short side direction (width direction) D2. Yes.
The hypotenuse 1a and the hypotenuse 1b are cut surfaces when the optical sheet 1 is cut from the laminated sheet 10 (details will be described later).
Hereinafter, each layer 11-15 shown in the cross section of FIG. 1 is demonstrated.

(Protective layer 11)
The protective layer 11 is the outermost surface (outermost layer) of the laminated sheet 10 in order to protect the surface of the portion used as the optical sheet 1 in the laminated sheet 10 during production, transportation, storage, etc. It is a layer provided for. The protective layer 11 is a layer that is removed when the optical sheet 1 formed from the laminated sheet 10 is used in an image display device. Therefore, the protective layer 11 is comprised by the film (henceforth a "protective film") which can be peeled after bonding once. As such a protective film, a known film can be used.

  The protective film has an adhesive layer (not shown) composed of an adhesive on one surface of a substrate (not shown). Examples of the base material of the protective film include polyester resins such as polyethylene terephthalate, polyamide resins such as nylon 6, films made of polyolefin resins such as polyethylene and polypropylene, paper such as fine paper, parchment paper, and sulfuric acid paper. Is mentioned. The base material of the protective film can be composed of a single layer or a laminate of two or more layers made of the above materials.

  Although the thickness of the base material of a protective film is not specifically limited, 10 micrometers or more and 100 micrometers or less are preferable. In order to improve the adhesion between the substrate and the pressure-sensitive adhesive layer, easy adhesion treatment such as corona discharge treatment, plasma treatment, primer coating, degreasing treatment, and surface roughening treatment is applied to the surface of the substrate as necessary. It can also be done.

  In addition, the pressure-sensitive adhesive layer of the protective film is required to leave no pressure-sensitive adhesive on the base material layer 12 described later, which becomes an adherend upon peeling. Therefore, the adhesive strength of the adhesive needs to be in an appropriate range. Therefore, the adhesive strength of the adhesive is preferably about 1 N / 25 mm or less. Examples of such an adhesive include natural rubber, synthetic rubber, acrylic resin (hereinafter referred to as “acrylic”), silicone resin, polyester resin, and the like.

(Base material layer 12)
The base material layer 12 is a layer serving as a base material for forming the optical functional layer 13 described in detail later. The base material layer 12 is preferably composed of a material mainly composed of polyethylene terephthalate (PET) from the viewpoints of performance, mass productivity, price, availability, and the like. Here, “main component” means that 50% by mass or more of PET is contained with respect to the entire material forming the base material layer (hereinafter the same). Moreover, the base material layer 12 has PET as a main component and may contain other resins. Further, various additives may be appropriately added to the base material layer 12. Examples of general additives include phenol-based antioxidants, lactone-based stabilizers, and the like.

  However, the main component of the material constituting the base material layer 12 is not necessarily PET, and may be other materials. Examples of other materials include acrylic resins such as polymethyl methacrylate, styrene resins such as polystyrene, cellulose resins such as triacetyl cellulose, and polycarbonate resins. Moreover, you may add additives, such as a ultraviolet absorber, a filler, a plasticizer, an antistatic agent, in these resins suitably as needed.

(Optical function layer 13)
The optical functional layer 13 is a layer having a function of appropriately absorbing stray light and external light while controlling the optical path of the video light incident from the video source side.
As shown in FIG. 3, the optical functional layer 13 is formed between a plurality of light transmission parts 16 arranged in parallel along the layer surface so as to be able to transmit light, and can absorb light. A light absorbing portion 17. The light transmission part 16 and the light absorption part 17 are linearly extended in the direction (extension direction D1) orthogonal to the direction (width direction D2) in which they parallel. The optical functional layer 13 includes the light transmitting unit 16 and the light absorbing unit 17 as described above, and controls the optical path of the image light incident from the image source side when it is provided in the display device. It has the function of absorbing light appropriately.

  The light transmission part 16 is a part having a function of transmitting image light, and is an element having a substantially trapezoidal cross section in the cross section shown in FIGS. 1 and 3. The upper base and the lower base longer than the upper base in the substantially trapezoidal cross section are arranged in the direction along the layer surface of the optical functional layer 13 (width direction D2). Note that “upper bottom” and “lower bottom” are expressions based on a trapezoidal shape, and may not coincide with the vertical direction (thickness direction D3) of the sheet (hereinafter the same).

  The light transmission part 16 has a refractive index of Np and has light transmittance. Such a light transmission part 16 can be comprised by hardening | curing a light transmission part structural composition. The value of the refractive index Np is not particularly limited, but is preferably 1.49 to 1.56 from the viewpoint of the availability of the applied material. As the light transmissive part constituting composition, those that can be cured by light such as ultraviolet rays are preferable. For example, a photocurable resin composition containing a photocurable prepolymer, a reactive dilution monomer, and a photopolymerization initiator is preferably used. It is done.

  Next, the light absorption unit 17 will be described. The light absorbing portion 17 is an element that is disposed between the light transmitting portions 16 and has a substantially trapezoidal surface in the cross section shown in FIGS. 1 and 3. The upper base and the lower base longer than the upper base in the substantially trapezoidal cross section of the light absorbing portion 17 are arranged in the direction along the layer surface of the optical functional layer 13 (width direction D2). A surface corresponding to the lower base of the substantially trapezoidal cross section of the light absorbing portion 17 is arranged in parallel between the upper bases of the light transmitting portion 16. One surface of the optical functional layer 13 is formed by the lower bottom of the light absorbing portion 17 and the upper bottom of the light transmitting portion 16. The hypotenuse in the substantially trapezoidal cross section of the light absorbing portion 17 preferably forms an angle of 0 degrees or more and 10 degrees or less with respect to the normal direction (thickness direction D3) of the layer surface of the optical function layer 13.

  The trapezoid is not limited to an isosceles trapezoid and includes an unequal leg trapezoid. When the angle of the hypotenuse in the trapezoid is close to 0 degrees, the cross sections of the light transmitting portion 16 and the light absorbing portion 17 are substantially rectangular. Further, the oblique side of the light absorbing portion 17 does not necessarily have a constant inclination, and may be a polygonal line or a curved line. Furthermore, the cross section of the light absorption part 17 may be a substantially triangular shape with a very short upper base.

  The light absorbing portion 17 is made of a predetermined material having a refractive index Nb smaller than the refractive index Np of the light transmitting portion 16. Thus, by setting the magnitude relationship between the refractive index Np of the light transmitting portion 16 and the refractive index Nb of the light absorbing portion 17 to Np> Nb, the image light from the image source incident on the light transmitting portion 16 is absorbed by light. It can be totally reflected by Snell's law at the interface between the portion 17 and the light transmitting portion 16 to provide a bright image to the observer. The difference in refractive index between Np and Nb is not particularly limited, but is preferably greater than 0 and 0.06 or less.

  Further, in the present embodiment, the refractive index magnitude relationship is preferably Np> Nb as described above, but is not necessarily limited to this. The refractive index of the light transmission part and the refractive index of the light absorption part may be the same, and the refractive index of the light transmission part may be smaller than the refractive index of the light absorption part.

  In addition, the light absorbing portion 17 in the present embodiment has a light absorbing portion constituting composition including the light absorbing particles 18 and the binder 19 in which the light absorbing particles 18 are dispersed in the grooves between the light transmitting portions 16. It is configured by being filled. As a result, stray light that is incident on the inside of the light absorbing portion 17 without being reflected by Snell's law at the interface between the light transmitting portion 16 and the light absorbing portion 17 can be absorbed by the light absorbing particles 18. Furthermore, external light from the viewer side that is incident at a predetermined angle can be appropriately absorbed by the light absorbing particles 18, and the contrast of the image can be improved.

  Note that configuring the light absorbing portion 17 with a predetermined material having the refractive index Nb means that the binder 19 is configured with a material having the refractive index Nb, for example. Although what is used as the binder 19 is not specifically limited, what is hardened | cured by light, such as an ultraviolet-ray, is preferable, for example, the reactive dilution monomer and the photoinitiator were mix | blended with the photocurable prepolymer. A photocurable resin composition is preferably used.

The light absorbing particles 18 are contained in the light absorbing portion constituent composition, and act to absorb stray light and external light when the light absorbing portion 17 is configured.
The light absorbing particles 18 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 the image light. May be used. Specifically, organic light particles colored with metal salts such as carbon black, graphite, black iron oxide, dyes, pigments, colored glass beads, and the like can be used as the light absorbing particles 18. The light-absorbing particles 18 are usually included in the light-absorbing part constituting composition in the range of 3% by mass to 30% by mass. The average particle diameter of the light absorbing particles 18 is preferably 1.0 μm or more and 20 μm or less.

  Further, depending on the material constituting the light transmission part 16, the surface of the light absorption part 17 may be filled on the same plane (smooth) with respect to the surface of the light transmission part 16, or the light absorption part 17. A recess may be formed on the top.

  In addition, the means for absorbing light by the light absorption part 17 is not limited to the method by the light absorption particle 18 like this embodiment. For example, the whole light absorption part can also be colored using the light absorption part structural composition colored with the pigment or the dye.

(Adhesive layer 14)
As shown in FIG. 1, the adhesive layer 14 is a layer comprised by the adhesive composition containing an adhesive. The pressure-sensitive adhesive refers to one type of adhesive. When bonding, it is performed at room temperature (for example, 15 to 40 ° C.), and the surface is only sticky by pressing moderately, usually lightly by hand. It means that it can be bonded only by its properties. The material of the pressure-sensitive adhesive composition is not particularly limited as long as it transmits light and has appropriate adhesiveness. The adhesive strength of the pressure-sensitive adhesive layer 14 can be, for example, about several N / 25 mm to 20 N / 25 mm.

  The pressure-sensitive adhesive that can be used for the pressure-sensitive adhesive layer 14 is not particularly limited as long as necessary film forming properties, light transmittance, pressure-sensitive adhesive properties, and weather resistance are realized, and various conventionally known pressure-sensitive adhesives can be used. It can be appropriately selected and used. The higher the transparency of the pressure-sensitive adhesive layer 14 is, the better. However, the light transmittance is preferably such that the wavelength average light transmittance in the visible light region of 380 to 780 nm is 70% or more, more preferably 80% or more.

(Coating layer 15)
The coating layer 15 is a layer that covers the pressure-sensitive adhesive layer 14 in a peelable manner. The coating layer 15 is a layer that can also be used as a base material when the pressure-sensitive adhesive layer 14 is formed.

  Since the pressure-sensitive adhesive layer 14 is used when the optical sheet 1 is bonded to another member, the coating layer 15 needs to be peeled off from the pressure-sensitive adhesive layer 14. In this case, as the coating layer 15, for example, the same material as the base material of the release film used for the protective layer 11 can be used. As described above, when the coating layer 15 is used on the assumption that the optical sheet 1 is peeled and discarded when the optical sheet 1 is used, the coating layer 15 uses the optical sheet 1 as another member via the adhesive layer 14. Until it is bonded, it serves to prevent foreign matter from adhering to the pressure-sensitive adhesive layer 14 and the pressure-sensitive adhesive layer 14 from coming into contact with other things.

  Next, the manufacturing method of the optical sheet 1 of 1st Embodiment of this invention is demonstrated. The manufacturing method of the optical sheet 1 of 1st Embodiment has lamination sheet production process S10, sheet roll production process S20, and optical sheet cutting process S30. Hereinafter, each step will be described in detail.

FIGS. 4A and 4B are diagrams illustrating a laminated sheet manufacturing process of the optical sheet manufacturing method according to the first embodiment, where FIG. 4A is a first process, FIG. 4B is a second process, and FIG. 4C is a third process. FIG. FIG. 5 is a perspective view schematically showing a sheet roll manufacturing process of the optical sheet manufacturing method according to the first embodiment. FIG. 6 is a plan view illustrating an example of an arrangement relationship of the optical sheet with respect to the laminated sheet. FIG. 7 is an enlarged cross-sectional view showing a main part of the cutting device. FIG. 8 is an enlarged cross-sectional view of a main part showing an optical sheet cutting process of the optical sheet manufacturing method according to the first embodiment.
In the description of the laminated sheet 10, the longitudinal direction (feeding direction) of the laminated sheet 10 is referred to as “longitudinal direction D11”. The thickness direction of the laminated sheet 10 is referred to as “thickness direction D13”. A direction orthogonal to the longitudinal direction D11 and the thickness direction D13 is referred to as a “width direction D12”.

<Laminated sheet manufacturing process S10>
As shown in FIG. 4, the laminated sheet manufacturing step S <b> 10 is performed by attaching the first step for forming the optical functional layer 13, the second step for forming the adhesive layer 14, and the optical functional layer 13 and the adhesive layer 14. And a third step of combining.

  In the first step, as shown in FIG. 4A, after the light transmitting portion 16 is formed on one surface of the base material layer 12 in parallel in the width direction D12 of the base material layer 12, the light transmitting portion 16 The light absorbing part 17 is formed by filling the groove between them with the light absorbing part constituting composition including the light absorbing particles 18 and the binder 19 in which the light absorbing particles 18 are dispersed. Thereafter, the protective layer 11 is formed on the other surface of the base material layer 12 to form an optical main sheet for the laminated sheet.

  In the second step, as shown in FIG. 4 (b), the release film forming the coating layer 15 is used as a base material, and an adhesive is applied onto the release film and dried with a dryer or the like. The agent layer 14 is formed.

  In the third step, as shown in FIG. 4C, the dried adhesive surface of the adhesive layer 14 and the surface of the optical functional layer 13 of the optical main sheet are bonded together. In this way, a belt-like laminated sheet 10 is produced.

  In addition, after forming the laminated body of the adhesive layer 14 and the coating layer 15 in a 2nd process, you may perform the following processes. A temporary coating layer (not shown) is once attached to the surface of the pressure-sensitive adhesive layer 14 opposite to the coating layer 15, and the temporary coating layer, the pressure-sensitive adhesive layer 14, and the coating layer 15 are integrally laminated. Create a laminated sheet. This pressure-sensitive adhesive laminated sheet is wound into a roll to produce a sheet roll. The pressure-sensitive adhesive laminated sheet is pulled out from the sheet roll, and the temporary covering layer is peeled off from the pressure-sensitive adhesive layer 14 to expose the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer 14. And the 3rd process of bonding together the adhesion side of adhesive layer 14, and the surface of optical function layer 13 of an optical main sheet is performed.

<Sheet roll production process S20>
As shown in FIG. 5, the laminated sheet 10 produced in the laminated sheet production step S <b> 10 is wound into a roll shape in the direction D <b> 20 shown in FIG. 5 to produce a sheet roll 30.

<Optical sheet cutting process S30>
As shown in FIG. 5, the laminated sheet 10 having a predetermined length is pulled out in the direction D30 shown in FIG. 5 from the sheet roll 30 produced in the sheet roll production step S20.
Note that, from the drawn laminated sheet 10, the optical sheet 1 is formed by being punched into a rectangular shape in a plan view and cut as shown by a cutting line CL by a two-dot chain line in FIG. The longitudinal direction D11 of the laminated sheet 10 and the longitudinal direction (extending direction D1) of the optical sheet 1 formed from the laminated sheet 10 are parallel. The optical sheet 1 has a short side in the parallel direction (width direction D2) of the plurality of light transmission portions 16 in the optical functional layer 13 of the multilayer sheet 10 from the laminated sheet 10, and a direction (extending) perpendicular to the parallel direction. It is formed by being punched into a rectangular shape and cut in a plan view having the direction D1) as a long side.

  As shown in FIG. 7, the cutting device 2 includes a cutting blade 20, a cradle 21, and a transport table 22. The transport table 22 is placed on a horizontal surface 21 a that is the upper surface of the receiving table 21 and is disposed below the laminated sheet 10. The conveyance stand 22 is formed in a belt conveyor shape, and is movable in the longitudinal direction D11 of the laminated sheet 10. When cutting the laminated sheet 10 with the cutting blade 20, the cutting edge of the cutting blade 20 comes into contact with the transport table 22. Therefore, it is preferable that the conveyance base 22 has a hardness that allows the laminated sheet 10 to be cut and has a softness that can prevent damage to the cutting edge of the cutting blade 20. An example of the material for the carrier 22 having such physical properties is polyethylene terephthalate (PET).

  As shown in FIG. 7, in the thickness direction D13, the laminated sheet 10 is pulled out with the protective layer 11 positioned at the uppermost layer (outermost layer) and the covering layer 15 positioned at the lowermost layer. And the lower surface of the coating layer 15 located in the lowermost layer of the drawn laminated sheet 10 is placed and fixed on the horizontal surface 21a of the cradle 21 and the protective layer 11 located in the uppermost layer of the laminated sheet 10 is fixed. The cutting blade 20 is disposed above.

  As shown in FIG. 8, the cutting blade 20 is moved downward with respect to the laminated sheet 10 from the uppermost protective layer 11 side to the lowermost coating layer 15 side, thereby moving the cutting blade 20 toward the lowermost coating layer 15 side. As shown in FIG. 4, the width W1 on the protective layer 11 side is the smallest, the width W2 on the coating layer 15 side is the largest, that is, the width gradually increases from the protective layer 11 side toward the coating layer 15 side. 1 is cut. The optical sheet 1 has a substantially trapezoidal shape in a cross section in the thickness direction D3 (see FIGS. 1 and 2), and has a short side in the parallel direction (width direction D2) of the plurality of light transmission portions 16 in the optical functional layer 13 in plan view. And a rectangular sheet having a long side in a direction orthogonal to the parallel direction (extending direction D1).

  According to the first embodiment, when forming the optical sheet 1 by cutting the laminated sheet 10 into a rectangular shape in plan view, the protective layer 11 disposed on one outermost layer of the front and back surfaces of the laminated sheet 10 By cutting from the side toward the side of the coating layer 15 disposed in the other outermost layer, the distance at which the blade surface 20a of the cutting blade 20 contacts the pressure-sensitive adhesive layer 14 covered by the coating layer 15 is shortened. Is possible. Therefore, adhesion of the adhesive to the blade surface 20a of the cutting blade 20 can be reduced.

  Further, the sheet is cut by forming a substantially trapezoidal shape in the cross section in the thickness direction D3 so that the width on the protective layer 11 side is the smallest and the width gradually increases toward the coating layer 15 side. When the cutting blade 20 is later pulled in the reverse direction (upward) and moved, the blade surface 20a of the cutting blade 20 can be moved without rubbing against the cutting surface of the sheet. Therefore, adhesion of the adhesive to the blade surface 20a can be reduced, and the cutting blade 20 can be smoothly pulled out and moved. In addition, the protective layer 11 is pulled in the pulling direction of the cutting blade 20 by the adhesive attached to the blade surface 20a, and the optical sheet 1 is unexpectedly peeled off from the base material layer 12 or the optical functional layer 13. Deformation can be prevented. As a result, it is possible to provide the optical sheet 1 that has a good finish and has few defects such as deformation.

  Moreover, in the manufacturing method of the optical sheet 1 of 1st Embodiment, after the lamination sheet preparation process S10 and before optical sheet cutting process S30, the lamination sheet 10 is wound in roll shape and the sheet roll 30 is produced. A sheet roll manufacturing step S20 is provided. Therefore, the curing period of each layer 11, 12, 13, 14, 15 of the laminated sheet 10 can be sufficiently secured to stabilize the performance as an optical sheet, and the production of the laminated sheet 10 and the optical sheet 1 By separating the cutting, the productivity and quality can be improved.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 9 is a longitudinal sectional view along the width direction of the optical sheet according to the second embodiment.
In the optical sheet 1A of the second embodiment, the protective layer 11 is disposed on the optical functional layer 13 side, the pressure-sensitive adhesive layer 14 and the coating layer 15 are disposed on the base material layer 12 side, and in the thickness direction D3, The protective layer 11, the optical functional layer 13, the base material layer 12, the pressure-sensitive adhesive layer 14, and the coating layer 15 are arranged in this order and laminated integrally.

  As described above, the optical sheet 1A of the second embodiment is different from the optical sheet 1 of the first embodiment in the arrangement configuration of the optical functional layer 13 and the base material layer 12 (reverse), and is a laminated sheet. The width W1 on the side of the protective layer 11 is the smallest and the width W2 on the side of the coating layer 15 is the largest due to cutting from 10 to a rectangular shape in plan view and cutting from the side of the protective layer 11 toward the side of the coating layer 15. Thus, the substantially trapezoidal shape in the cross section in the thickness direction D3 and the effects and the like obtained in accordance with the trapezoidal shape are the same as in the first embodiment.

  Moreover, also about the manufacturing method of 1 A of optical sheets of 2nd Embodiment, similarly to the manufacturing method of the optical sheet 1 of 1st Embodiment, laminated sheet preparation process S10, sheet roll preparation process S20, and an optical sheet cutting process process S30. Therefore, the detailed description and illustration of the manufacturing method are omitted.

(Deformation)
The present invention is not limited to the first and second embodiments described above.
For example, in the above embodiment, as shown in FIG. 6, the longitudinal direction D11 of the laminated sheet 10 and the longitudinal direction (extending direction D1) of the optical sheet 1 formed from the laminated sheet 10 are parallel. This is not a limitation. As shown in FIG. 10, when the longitudinal direction (extending direction D1) of the optical sheet 1 is at an angle with respect to the longitudinal direction D11 of the laminated sheet 10 (in a non-parallel state), the optical direction from the laminated sheet 10 is increased. It can also be formed by cutting the sheet 1. The angle formed by the longitudinal direction (extending direction D1) of the optical sheet 1 with respect to the longitudinal direction D11 of the laminated sheet 10 is, for example, more than 0 ° and 45 ° or less.

In the said embodiment, although the laminated sheet 10 demonstrated the form provided with the protective layer 11, the base material layer 12, the optical function layer 13, the adhesive layer 14, and the coating layer 15, the laminated sheet 10 is used for a use. Accordingly, layers having other functions can be provided. As other layers that can be provided in the laminated sheet 10, those used in the conventional optical sheet can be used without any particular limitation. Specific examples include an electromagnetic wave shielding layer, an antiglare layer, an antireflection layer, a hard coat layer, a wavelength filter layer, and an impact absorption layer.
For example, as in the first embodiment, the protective layer 11, the base material layer 12, the optical function layer 13, the pressure-sensitive adhesive layer 14, and the coating layer 15 are arranged in this order in the thickness direction D3 and are integrally laminated. In the optical sheet 1, an antiglare layer or an antireflection layer can be provided between the protective layer 11 and the base material layer 12.

  In addition, as described above, these other layers can be bonded to other layers using the same adhesive layer as the adhesive layer 14. As the pressure-sensitive adhesive layer, a known pressure-sensitive adhesive can be used in the same manner as the pressure-sensitive adhesive layer 14. Similarly to the pressure-sensitive adhesive layer 14, an ultraviolet absorber, a near-infrared absorber, a neon line absorber, and a toning It is also possible to include pigments and the like. The stacking order and the number of stacking of these layers are appropriately determined according to the use of the optical sheet 1 cut from the stacking sheet 10. A description of the functions of these layers is omitted.

In the said embodiment, although the light transmission part 16 of the optical function layer 13 is formed in one surface of the base material layer 12 formed previously, it is not restrict | limited to this. The base material layer 12 and the light transmission portion 16 of the optical function layer 13 may be integrally formed.
In the manufacturing method of the said embodiment, although it demonstrated that it had lamination sheet production process S10, sheet roll production process S20, and optical sheet cutting process S30, sheet roll production process S20 was abbreviate | omitted, The optical sheet 1 (1A) may be cut directly from the laminated sheet 10 produced in the laminated sheet production step S10. That is, the optical sheet 1 (1A) may be cut from the sheet-like laminated sheet 10 instead of the roll.

In the manufacturing method of the said embodiment, although the two optical sheets 1 (1A) are cut in the width direction D12 from the lamination sheet 10, it is not restricted to this, One or three in the width direction D12 The above optical sheet 1 (1A) may be cut.
In addition, in the sheet roll production step S20 in which the laminated sheet 10 is wound into a roll shape to produce the sheet roll 30, the laminated sheet 10 is wound into a roll shape while spacers are arranged in the vicinity of both ends in the width direction D12 of the laminated sheet 10. You may turn. In this case, at the time of winding the laminated sheet 10, it is possible to prevent minute irregularities on the surface of the protective layer 11 from being transferred to the pressure-sensitive adhesive layer 14 side.

DESCRIPTION OF SYMBOLS 1 Optical sheet 1A Optical sheet 1a, 1b Oblique side 10 Laminated sheet 11 Protective layer 12 Base material layer 13 Optical functional layer 14 Adhesive layer 15 Covering layer 16 Light transmission part 17 Light absorption part 20 Cutting blade 30 Sheet roll

Claims (7)

A protective layer, a base material layer, a plurality of light transmission parts arranged in parallel along the surface of the base material layer, an optical functional layer having a light absorption part formed between the light transmission parts, and an adhesive layer An optical sheet formed in a rectangular shape in a plan view in which the protective layer and the coating layer are disposed on the outermost layer, and a coating layer that covers the pressure-sensitive adhesive layer in a peelable manner.
An optical sheet formed in a substantially trapezoidal shape in a cross section in the thickness direction so that the width on the protective layer side is the smallest and the width gradually increases toward the covering layer side. 2. The optical sheet according to claim 1, wherein in the thickness direction, the protective layer is disposed on the substrate layer side, and the pressure-sensitive adhesive layer and the coating layer are disposed on the optical functional layer side. 2. The optical sheet according to claim 1, wherein in the thickness direction, the protective layer is disposed on the optical functional layer side, and the pressure-sensitive adhesive layer and the coating layer are disposed on the base material layer side. A protective layer, a base material layer, a plurality of light transmission parts arranged in parallel along the surface of the base material layer, an optical functional layer having a light absorption part formed between the light transmission parts, and an adhesive layer A laminated sheet producing step of producing a laminated sheet in which a coating layer covering the pressure-sensitive adhesive layer so as to be peeled is integrally laminated, and the protective layer and the coating layer are arranged in an outermost layer;
By moving the cutting blade from the protective layer side toward the coating layer side with respect to the laminated sheet, the width of the protective layer side is the smallest and toward the coating layer side An optical sheet manufacturing method comprising: an optical sheet cutting process for cutting an optical sheet having a substantially trapezoidal shape in a cross section in the thickness direction and a rectangular shape in plan view so that the width gradually increases. 5. The optical sheet according to claim 4, further comprising a sheet roll forming step of winding the laminated sheet into a roll shape after the laminated sheet manufacturing step and before the optical sheet cutting step. Production method.   In the said lamination sheet preparation process, the said protective layer is arrange | positioned at the said base material layer side, The said adhesive layer and the said coating layer are arrange | positioned at the said optical function layer side. Manufacturing method of optical sheet. In the said lamination sheet preparation process, the said protective layer is arrange | positioned at the said optical function layer side, The said adhesive layer and the said coating layer are arrange | positioned at the said base material layer side. Manufacturing method of optical sheet.

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