JP7016729B2 - Manufacturing method of single-wafer film - Google Patents

Description

The present invention relates to a method for producing a single-wafer film for obtaining a single-wafer film from a multilayer film having an adhesive layer, and also relates to a production apparatus and a method for cutting the multilayer film.

Conventionally, as one of the methods for cutting a multilayer film containing a polarizing plate or the like, a method for cutting using a push-cutting blade is known (for example, Japanese Patent Application Laid-Open No. 2015-33727 (Patent Document 1)). Patent Document 1 describes that the occurrence of fluff on the cut surface can be suppressed by using a push-cutting blade whose surface roughness of the cutting edge is within a specific numerical range as the push-cutting blade used for cutting a multilayer film. There is.

JP-A-2015-33727

As described in Patent Document 1, when a multilayer film is cut using a push-cutting blade, streaky minute irregularities may occur in the vicinity of the cut portion on the surface of the multilayer film. When manufacturing a sheet-fed film by cutting a multilayer film for mobile devices such as smartphones, the size of the sheet-fed film is small, and the displayed characters and patterns are relatively small to fit the screen. Since it can be seen from a distance, even minute irregularities are easily noticeable and easily become defects in appearance. The present inventors have proceeded with studies and have found that such fine irregularities in the form of streaks are likely to occur when the multilayer film has an adhesive layer. Then, after further diligent studies, a method capable of suppressing such fine streaky irregularities was found and the present invention was reached.

An object of the present invention is to provide a method and an apparatus for producing a single-wafer film, and a method for cutting a multilayer film, which can suppress the occurrence of streak-like minute irregularities.

The present invention provides a method and an apparatus for producing a single-wafer film shown below, and a method for cutting a multilayer film.

[1] A method for producing a single-wafer film, which comprises a cutting step of cutting a multilayer film having an adhesive layer to obtain a single-wafer film from the multilayer film.
In the cutting step, the push-cutting blade is made to enter the multilayer film from the first surface of the multilayer film until it reaches the blade receiving plate arranged so as to be in contact with the second surface of the multilayer film. Including a push-cutting step of cutting the multilayer film,
The blade receiving plate is a method for manufacturing a single-wafer film having a indentation elastic modulus of 3.5 × ¹⁰⁹ Pa or less.

[2] The method for producing a single-wafer film according to [1], wherein the blade receiving plate has a indentation elastic modulus of 1.0 × ¹⁰⁹ Pa or less.

[3] The method for producing a single-wafer film according to [1] or [2], wherein the blade receiving plate has a tack value of 0.1 N or less on the surface of the multilayer film in contact with the second surface.

[4] The method for producing a single-wafer film according to any one of [1] to [3], wherein the multilayer film has a polarizing element.

[5] A single-wafer film manufacturing apparatus having a cut portion for cutting a multilayer film having an adhesive layer to obtain a single-wafer film from the multilayer film.
The cutting portion is arranged so as to be in contact with the push-cutting blade arranged so as to be able to enter the multilayer film from the first surface of the multilayer film and the second surface of the multilayer film, and the push-cutting portion has entered the multilayer film. Equipped with a blade receiving plate that can receive the blade,
The blade receiving plate is a single-wafer film manufacturing apparatus having a indentation elastic modulus of 3.5 × ¹⁰⁹ Pa or less.

[6] The single-wafer film manufacturing apparatus according to [5], wherein the blade receiving plate has a indentation elastic modulus of 1.0 × 10 ⁹ Pa or less.

[7] The single-wafer film manufacturing apparatus according to [5] or [6], wherein the blade receiving plate has a tack value of 0.1 N or less on the surface of the multilayer film in contact with the second surface.

[8] A cutting method for cutting a multilayer film having an adhesive layer.
The push-cutting blade is inserted into the multilayer film from the first surface of the multilayer film until it reaches the blade receiving plate arranged so as to be in contact with the second surface of the multilayer film, and cuts the multilayer film. Including the push-cutting process
The blade receiving plate is a method for cutting a multilayer film having an indentation elastic modulus of 3.5 × ¹⁰⁹ Pa or less.

[9] The method for cutting a multilayer film according to [5], wherein the blade receiving plate has a indentation elastic modulus of 1.0 × 10 ⁹ Pa or less.

[10] The method for cutting a multilayer film according to [8] or [9], wherein the blade receiving plate has a tack value of 0.1 N or less on the surface of the blade receiving plate that comes into contact with the second surface of the multilayer film.

[11] The method for cutting a multilayer film according to any one of [8] to [10], wherein the multilayer film has a polarizing element.

According to the present invention, it is possible to provide a method and an apparatus for producing a single-wafer film and a method for cutting a multilayer film, which can suppress the occurrence of streak-like minute irregularities.

It is a schematic diagram schematically showing an example of a cutting process for obtaining a sheet-fed film from a multilayer film. It is a schematic diagram schematically showing an example of a cutting process for obtaining a sheet-fed film from a multilayer film. It is a schematic diagram schematically showing an example of a cutting process for obtaining a sheet-fed film from a multilayer film. It is sectional drawing which shows typically the cutting apparatus which has a push cutting blade. It is (a) sectional drawing, (b) oblique view from the lower surface, (c) bottom view which shows an example of a push-cutting edge member. It is a figure which shows typically the cutting operation by a push cutting blade. It is a bottom view which shows an example different from FIG. 5 of a push cutting edge member. It is an image diagram which shows the streak-like minute unevenness generated in the vicinity of the cut surface of a multilayer film surface. It is schematic sectional drawing which shows an example of the specific layer structure of a multilayer film schematically.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In all the drawings below, the scales are appropriately adjusted and shown in order to make each component easier to understand, and the scale of each component shown in the drawings does not necessarily match the scale of the actual component.

[Manufacturing method of sheet-fed film]
The method for producing a single-wafer film according to the present embodiment includes a cutting step of cutting a multilayer film having an adhesive layer to obtain a single-wafer film from the multilayer film. The cutting step cuts the multilayer film by allowing the push-cutting blade to penetrate the multilayer film from the first surface of the multilayer film until it reaches the blade receiving plate arranged so as to contact the second surface of the multilayer film. Including the push-cutting process.

<Cutting process>
1 to 3 are schematic views schematically showing an example of a cutting process of cutting a multilayer film to obtain a single-wafer film from the multilayer film, respectively. In FIGS. 1 to 3, the dotted line indicates a cutting line in the cutting process. In the example shown in FIG. 1, a long multilayer film 10a is cut in a direction orthogonal to the longitudinal direction using a push-cutting blade having a linear cutting edge (FIG. 1A), and the multilayer film 10b is sliced into small pieces. (FIG. 1 (b)), and then the fragmented multilayer film 10b is cut in the longitudinal direction of the original multilayer film 10a using a push-cutting blade having a linear cutting edge (FIG. 1 (b)). )), A single-wafer film 11 of a desired size is obtained (FIG. 1 (c)).

In the example shown in FIG. 2, a long multilayer film 10a is punched and cut with a mold-shaped push-cutting blade (FIG. 2A) to obtain a single-wafer film 11 having a desired size (FIG. 2B). ).

In the example shown in FIG. 3, a long multilayer film 10a is cut in a direction orthogonal to the longitudinal direction using a push-cutting blade having a linear cutting edge (FIG. 3A), and the multilayer film 10c is sliced into small pieces. (FIG. 3 (b)), and then punching with a mold-shaped push-cutting blade to obtain a single-wafer film 11 of a desired size (FIG. 3 (c)).

The cutting direction of the cutting step shown in FIGS. 1 to 3 is not particularly limited, and when cutting a multilayer film having orientation characteristics, a single-wafer film 11 having desired orientation characteristics can be obtained. Determine the cutting direction.

In each of the examples shown in FIGS. 1 to 3, one or a plurality of single-wafer films can be obtained from the multilayer film through one or a plurality of cuttings. The number of cuts in the cutting process is not limited. Further, in the above, the case where all the cutting in the cutting process is the push-cutting process has been described, but the case is not limited as long as any of the cutting is the push-cutting step. It may be a cutting step including cutting by rotation of a round blade, and the like. That is, it suffices that the obtained sheet-fed film includes a cut surface obtained by the push-cutting step. According to the push-cutting step, streak-like minute irregularities are likely to occur in the vicinity of the cut portion on the surface of the multilayer film, but in the present embodiment, even if all cutting is the push-cutting step, such streak-like minute irregularities are likely to occur. It is possible to suppress the occurrence of unevenness.

<Oshikiri process>
FIG. 4 is a schematic view schematically showing a cutting device having a push-cutting blade. With the cutting device 20 shown in FIG. 4, the push-cutting step according to the present embodiment can be carried out. The cutting device 20 mounts a push-cutting blade member 21 having a push-cutting blade, a control unit 24 for controlling the vertical movement of the push-cutting blade member 21, and a multilayer film 10 having a blade receiving plate 22 on the upper surface thereof. It is provided with a stand 23. The multilayer film 10 is placed on the mounting table 23 so as to be in contact with the blade receiving plate 22. In the multilayer film 10 mounted on the mounting table 23, the surface in contact with the blade receiving plate 22 is referred to as the second surface 102, and the upper surface facing the second surface 102 is referred to as the first surface 101. In the push-cutting step, the push-cutting blade member 21 moves downward, so that the push-cutting blade enters the multilayer film 10 from the first surface 101 of the multilayer film 10 until it reaches the blade receiving plate 22. After that, the push-cutting blade member 21 moves upward, so that the push-cutting blade is separated from the multilayer film 10. The multilayer film 10 is cut by the vertical movement of the push-cutting blade member 21.

FIG. 5A is a cross-sectional view showing in detail the push-cutting blade member 21a, which is an example of the push-cutting blade member 21 shown in FIG. FIG. 5B shows an oblique view from the lower surface of the push-cutting blade member 21a, and the cross-sectional view taken along the line aa of FIG. 5B corresponds to FIG. 5A. FIG. 5C shows a bottom view of the push cutting blade member 21a. The push-cutting blade member 21a includes a push-cutting blade 211a having a linear cutting edge portion, a holding portion 213a for holding the push-cutting blade 211a, and an elastic body 212a arranged on the lower surface of the holding portion 213a. The lowermost surface of the elastic body 212a is located at the same as the cutting edge portion of the push-cutting blade 211a or below the cutting edge portion of the push-cutting blade 211a.

6 (a) to 6 (c) schematically show a cutting operation by the push-cutting blade 211a when cutting the multilayer film 10 by the cutting device provided with the push-cutting blade member 21a shown in FIGS. 5 (a) to 5 (c). It is a figure shown in. In the cutting operation, the push-cutting blade member 21a moves downward (FIG. 6 (a)), and the lowermost surface of the elastic body 212a of the push-cutting blade member 21a comes into contact with the first surface 101 of the multilayer film 10 (FIG. 6 (b). )). After that, as the push-cutting blade member 21a further moves downward, the elastic body 212a contracts on the first surface 101 of the multilayer film 10, and only the cutting blade 211a is transferred from the first surface 101 of the multilayer film 10 to the multilayer film 10. It enters inside and continues to enter until it reaches the blade receiving plate 22 (FIG. 6 (c)). When the cutting blade 211a reaches the blade receiving plate 22, the moving direction of the push-cutting blade member 21 is switched upward, and the cutting blade 211a is pulled out from the multilayer film 10. By the above cutting operation, the multilayer film 10 is cut in the laminating direction.

The push-cutting blade 211a included in the cutting blade member 21a is not limited to the push-cutting blade capable of linearly cutting the multilayer film 10 as shown in FIGS. 5 (a) to 5 (c), and can perform desired cutting. Can be designed to be. It may be a type-shaped push-cutting blade capable of punching a rectangular single-wafer film from the multilayer film 10. FIG. 7 shows a bottom view of an example of a push-cutting blade member provided with a shaped push-cutting blade. The push-cutting blade member 21b shown in FIG. 7 includes a push-cutting blade 211b, a holding member, and an elastic body 212b, and has the same configuration as the push-cutting blade member 21a shown in FIG. 5 except that the shape of the push-cutting blade 211b is different. The multilayer film 10 can be cut by the method described above.

As the push cutting blades 21a and 21b, Thomson blades are preferably used. The Thomson blade may have a resin-processed surface. The elastic bodies 212a and 212b are not limited as long as they can shrink on the surface of the multilayer body and can fix the multilayer body by sandwiching the multilayer body 10 together with the blade receiving plate 22 at the time of cutting. Rubber, silicone rubber, porous sponge and the like are preferably used.

In the cutting apparatus according to the present embodiment, the blade receiving plate 22 which is placed on the mounting table 23 and comes into contact with the second surface 102 of the multilayer film ¹⁰ has a indentation elastic modulus of 3.5 × 109 Pa or less. , 1.0 × 10 ⁹ Pa or less, more preferably 5.0 × 10 ⁸ Pa or less, still more preferably 5.0 × 10 ⁷ Pa or less. When the indentation elastic modulus of the blade receiving plate 22 is within the numerical range, it is possible to suppress streak-like minute irregularities generated in the vicinity of the cut surface on the surface of the multilayer film 10. Further, the blade receiving plate 22 preferably has a indentation elastic modulus of 1.0 × ¹⁰⁶ Pa or more. This is because if the indentation elastic modulus of the blade receiving plate 22 is too low, the multilayer film 10 is greatly deformed at the time of cutting, and it becomes difficult to obtain a clean cut surface. The indentation elastic modulus specified in the present specification is a value measured by a microhardness tester "H100SMC" (manufactured by Fisher Instruments) and a Vickers quadrangular pyramid diamond indenter having a facing angle of 136 ° as an indenter.

The blade receiving plate 22 is not particularly limited as long as the indentation elastic modulus is 3.5 × 10 ⁹ Pa or less, but from the viewpoint that the indentation elastic modulus within the above numerical range can be easily formed, the polyurethane rubber sheet, A blade receiving plate 22 using a silicone rubber sheet, a porous sponge, or the like is preferable. Further, from the viewpoint that the multilayer film 10 after cutting can be easily peeled off, the tack value of the surface of the blade receiving plate 22 in contact with the multilayer film 10 is preferably 0.1 N or less. Usually, the tack value is 0.001N or more. The tack value specified in the present specification is a value measured by performing a pick-up tack test (load 800 gf, contact time 30 seconds, pulling speed 300 mm / min, temperature 23 ° C.) according to the method described in JIS T 9233.

The blade receiving plate 22 may have a laminated structure having a surface layer that can be adjusted to a desired tack value on the surface in contact with the multilayer film 10. Examples of such a surface layer include an acrylic film, a cellulose acetate film, and a cycloolefin polymer film. The thickness of the surface layer is not particularly limited, but is, for example, 40 to 80 μm, preferably 60 to 100 μm.

The surface area of the blade receiving plate 22 is not particularly limited, but it is preferably larger than the surface area of the multilayer film 10 to be cut. The thickness of the blade receiving plate 22 is not particularly limited as long as it does not easily penetrate the push-cutting blade, but is, for example, 0.5 to 5 mm, preferably 0.6 to 3 mm.

<Other processes>
The method for producing a single-wafer film according to the present embodiment may include steps other than the above-mentioned cutting step, for example, a multilayer film manufacturing step for manufacturing a multilayer film, and winding a multilayer film wound in a roll shape. Examples thereof include a winding step of unwinding, a transporting step of transporting a multilayer film or a sheet-fed film, and a drying step of drying a multilayer film or a sheet-fed film.

<Multilayer film>
The multilayer film is not particularly limited as long as it has an adhesive layer. The multilayer film is, for example, an optical laminated film. This is because, in the case of an optical laminated film, even a minute unevenness tends to cause a problem in appearance. The thickness of the multilayer film is, for example, 5 to 3000 μm, preferably 100 to 300 μm. The layer structure of the multilayer film is preferably a layer structure in which the pressure-sensitive adhesive layer is not exposed on the outermost surface so that dirt does not easily adhere to the pressure-sensitive adhesive layer in the cutting step.

When the multilayer film has an adhesive layer, when it is cut using a push-cutting blade, fine streaky irregularities are likely to occur in the vicinity of the cut surface on the surface of the multilayer film. , It is possible to suppress the occurrence of such minute irregularities. More specifically, the minute unevenness is often a streak-like ridge extending in a direction substantially parallel to the cut surface, and often occurs on the second surface in contact with the blade receiving plate. The mechanism by which minute irregularities are generated is not clear, but one possible mechanism is that the entry of the push-cutting blade causes different shear stresses in each layer, and the difference in shear stress acting on the two layers in contact with the adhesive layer. As a result, the pressure-sensitive adhesive layer may be locally deformed. It is presumed that such local deformation is caused by the softness of the adhesive layer as compared with other layers.

FIG. 8 is an image diagram showing fine streak-like irregularities generated in the vicinity of the cut surface on the surface of the multilayer film. The mechanism of generation of minute irregularities described with reference to FIG. 8 is one possible mechanism, and the minute irregularities suppressed by the method for producing a single-wafer film of the present embodiment are generated by such a mechanism. It is not limited to the unevenness, and is not limited to the minute unevenness schematically shown in FIG. In FIG. 8, as the multilayer film 10 to be cut, a multilayer film composed of a layer 101, an adhesive layer 102, and a layer 103 is assumed. When the push-cutting blade 211 is inserted into the multilayer film 10, different shear stresses are generated in each layer, and the adhesive layer 102 is softer than the adjacent layers 101 and 103, so that the adhesive layer 102 acts on the two layers 101 and 103. Due to the difference in stress, the local area near the cut surface of the pressure-sensitive adhesive layer 102 is slightly raised to form a ridge 102a. Due to the ridges 102a of the pressure-sensitive adhesive layer 102, the layer 103 adjacent to the pressure-sensitive adhesive layer 102 may also be slightly raised to form the ridges 103a. In this way, the ridges 102a formed on the pressure-sensitive adhesive layer 102 and the ridges 103a formed on the layer 103 cause streak-like irregularities that are visually visible in appearance.

(Adhesive layer)
The pressure-sensitive adhesive layer can be composed of a pressure-sensitive adhesive composition containing a resin as a main component, such as (meth) acrylic, rubber, urethane, ester, silicone, and polyvinyl ether. Among them, a pressure-sensitive adhesive composition using a (meth) acrylic resin having excellent transparency, weather resistance, heat resistance and the like as a base polymer is preferable. The pressure-sensitive adhesive composition may be an active energy ray-curable type or a thermosetting type.

Examples of the (meth) acrylic resin (base polymer) used in the pressure-sensitive adhesive composition include butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2- (meth) acrylate. A polymer or copolymer having one or more (meth) acrylic acid esters such as ethylhexyl as a monomer is preferably used. It is preferable that the base polymer is copolymerized with a polar monomer. Examples of the polar monomer include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylic acid, hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, and glycidyl ( Examples thereof include monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group and the like, such as meth) acrylate.

The pressure-sensitive adhesive composition may contain only the above-mentioned base polymer, but usually further contains a cross-linking agent. The cross-linking agent is a divalent or higher metal ion that forms a carboxylic acid metal salt with a carboxyl group; a polyamine compound that forms an amide bond with a carboxyl group; poly. Examples thereof include epoxy compounds and polyols that form an ester bond with a carboxyl group; polyisocyanate compounds that form an amide bond with a carboxyl group. Of these, polyisocyanate compounds are preferable.

The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by being irradiated with active energy rays such as ultraviolet rays and electron beams, and has adhesiveness even before irradiation with active energy rays. It is a pressure-sensitive adhesive composition having a property that it can be brought into close contact with an adherend such as, etc., and can be cured by irradiation with active energy rays to adjust the adhesive force. The active energy ray-curable pressure-sensitive adhesive composition is preferably an ultraviolet-curable type. The active energy ray-curable pressure-sensitive adhesive composition further contains an active energy ray-polymerizable compound in addition to the base polymer and the cross-linking agent. Further, if necessary, a photopolymerization initiator, a photosensitizer, or the like may be contained.

The pressure-sensitive adhesive composition includes fine particles for imparting light scattering properties, beads (resin beads, glass beads, etc.), glass fibers, resins other than the base polymer, pressure-sensitive adhesives, and fillers (metal powders and other inorganic powders). Etc.), antioxidants, UV absorbers, dyes, pigments, colorants, defoaming agents, corrosion inhibitors, photopolymerization initiators and other additives can be included.

It can be formed by applying an organic solvent diluted solution of the above pressure-sensitive adhesive composition on a substrate and drying it. When the active energy ray-curable pressure-sensitive adhesive composition is used, the formed pressure-sensitive adhesive layer can be irradiated with active energy rays to obtain a cured product having a desired degree of curing.

The thickness of the pressure-sensitive adhesive layer can be, for example, 1 to 40 μm. When the thickness of the pressure-sensitive adhesive layer is 1 to 40 μm, fine streaky irregularities are likely to occur due to the push-cutting step, but according to the method for producing a single-wafer film of the present embodiment, the thickness of the pressure-sensitive adhesive layer is 1 to 40 μm. Even if there is, it is possible to suppress the occurrence of streak-like minute irregularities.

The pressure-sensitive adhesive layer can exhibit a storage elastic modulus of 0.15 to 1 MPa at a temperature of 20 ° C. and an angular frequency of 1,000 radians / second. When the pressure-sensitive adhesive layer has such a storage elastic modulus, it is often softer than other layers and tends to have minute irregularities. However, according to the method for producing a single-wafer film of the present embodiment, the pressure-sensitive adhesive layer Even if the storage elastic modulus at a temperature of 20 ° C. is 0.15 to 1 MPa, the generation of minute irregularities can be suppressed. Further, when the multilayer film of the present embodiment has a plurality of pressure-sensitive adhesive layers, fine irregularities tend to be more likely to occur in the pressure-sensitive adhesive layer having a smaller storage elastic modulus. According to the method for producing a single-wafer film of the present embodiment, even when a plurality of pressure-sensitive adhesive layers are provided, it is possible to suppress the generation of minute irregularities in all the pressure-sensitive adhesive layers.

The storage elastic modulus of the pressure-sensitive adhesive layer can be measured using a commercially available viscoelasticity measuring device, for example, a viscoelasticity measuring device “DYNAMIC ANALYZER RDA II” manufactured by REOMETRIC.

As a method for adjusting the storage elastic modulus within the above range, an oligomer, specifically, a urethane (meth) acrylate-based oligomer is further added to a base polymer or a pressure-sensitive adhesive composition containing a cross-linking agent. An active energy ray-curable pressure-sensitive adhesive composition (preferably an ultraviolet-curable pressure-sensitive adhesive composition) may be used. More preferably, the pressure-sensitive adhesive layer is appropriately cured by irradiating it with active energy rays.

(Example of layer configuration of multilayer film)
FIG. 9 is a schematic cross-sectional view schematically showing an example of a specific layer structure of a multilayer film used or manufactured in the method for producing a single-wafer film according to the present embodiment. The multilayer film 10d includes a polarizing plate 100 including a polarizing element (not shown in FIG. 9), a protective film 60 laminated on one surface thereof, and a first pressure-sensitive adhesive layer 31 laminated on the other surface. A peelable separate film 70 for temporarily protecting the first pressure-sensitive adhesive layer 31 is laminated on the outer surface of the first pressure-sensitive adhesive layer 31. On the other hand, the surface of the polarizing plate 100 on the protect film 60 side (the surface to which the protect film 60 is bonded) and the surface on the first pressure-sensitive adhesive layer 31 side (the surface to which the first pressure-sensitive adhesive layer 31 is bonded) are, for example. It can be the surface of a protective film, another optical film or a layer added on the film.

The protective film 60 may be laminated by adhering the protective film 60 to the polarizing plate 100 on one surface which is adhesive and the other surface is non-adhesive. Examples of such a protective film 60 include a so-called self-adhesive protective film. The self-adhesive protective film is, for example, a resin film composed of a non-adhesive resin layer 61 made of a non-adhesive resin and an adhesive resin layer 62 made of a self-adhesive resin. Examples of the self-adhesive protective film include "Tretec" (Toray Film Processing Co., Ltd.). Further, there is also a protective film composed of a resin film (base film) 61 and a second pressure-sensitive adhesive layer 62 laminated on the resin film (base film) 61, which is laminated and laminated on the polarizing plate 100 via the pressure-sensitive adhesive layer. .. When the protective film 60 has the second pressure-sensitive adhesive layer 62, the storage elastic modulus thereof is usually larger than the storage elastic modulus of the first pressure-sensitive adhesive layer.

The polarizing plate 100 is a polarizing element including at least a polarizing element and a first pressure-sensitive adhesive layer 31, and further includes a protective film usually bonded to one side or both sides of the polarizing element. In addition to the protective film, the polarizing plate 100 can also include another optical film such as a film having an optical function different from that of the polarizing element, and a layer added on the film such as an optical layer. Various optical films including the protective film can be bonded via an adhesive layer or an adhesive layer. The polarizing plate 100 may or may not include a pressure-sensitive adhesive layer.

The thickness of the polarizing plate 100 is usually 20 to 200 μm, preferably 30 to 150 μm, more preferably 40 to 120 μm, and further preferably 50 to 100 μm.

The multilayer film 10d is obtained by laminating another raw material film continuously unwound from the film roll on the raw material film continuously unwound from the film roll and conveyed, and forming a long laminated film. The film may be produced by a so-called roll-to-roll method in which the film is wound into a roll, or may be a multilayer film obtained by further cutting the film. In the method for producing a single-wafer film according to the present embodiment, the multilayer film 10d is cut in the cutting step to produce the single-wafer film.

When the multilayer film 10d includes both the first pressure-sensitive adhesive layer 31 and the second pressure-sensitive adhesive layer 62 as the pressure-sensitive adhesive layer, the first pressure-sensitive adhesive layer 31 on which the peelable separate film 70 is laminated is usually better. , It is easy to cause minute unevenness in the push-cutting process. It is considered that this may be due to the fact that the separate film 70 is once peeled off or displaced due to the action of the shear stress, and the displacement of the pressure-sensitive adhesive layer is fixed.

When the multilayer film 10d is cut by the cutting device shown in FIG. 4, the protect film 60 side is used as the first surface and the separate film 70 side is used as the second surface so that the separate film 70 comes into contact with the blade receiving plate 22. The resin film 61 constituting the protect film 60 has a blade receiving plate with the separate film 70 side as the first surface and the protect film 60 side as the second surface. It may be placed on the mounting table 23 so as to come into contact with 22 and cut. According to the method for producing a single-wafer film of the present embodiment, even when the multilayer film 10d is placed in any direction, it is possible to suppress the generation of streak-like minute irregularities due to the push-cutting process.

The shape of the uncut multilayer film 10d is not particularly limited, but is typically long (strip-shaped). The length in the length direction and the length in the width direction of the uncut multilayer film 10d are not particularly limited, but usually, the length in the length direction of the multilayer film 10d is 100 m to 20,000 m, and the length in the width direction is It is 1000 mm to 1500 mm. The multilayer film 10d may be cut into small pieces of the multilayer film 10d and then subjected to the pressing step. In this case, the shape of the small multilayer film 10d is not particularly limited, but it is preferably a square shape having a long side and a short side, and is typically a rectangle. The lengths of the long side and the short side are not particularly limited, but for example, the length of the long side is 900 mm or less, and the length of the short side is 800 mm or less.

The size, shape and cutting angle of the single-wafer film are not particularly limited. The single-wafer film is preferably a square shape, and more preferably a square shape having a long side and a short side. This rectangular shape is preferably rectangular. When the single-wafer film is rectangular, the length of the long side is, for example, 50 mm to 300 mm, preferably 70 mm to 200 mm. The length of the short side is, for example, 30 mm to 200 mm, preferably 40 mm to 100 mm. The smaller the size of the sheet-fed film, the more conspicuous the minute irregularities generated on the surface of the sheet-fed film near the cut surface in the push-cutting step, and the more likely it is to become a defect in appearance. Even when the size of the single-wafer film is small, it is possible to prevent the occurrence of minute irregularities.

(1) Polarizer A splitter has the property of absorbing linearly polarized light having a vibrating surface parallel to its absorption axis and transmitting linearly polarized light having a vibrating surface orthogonal to the absorption axis (parallel to the transmission axis). It is a type polarizing element, and a polarizing film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film can be preferably used. The decoder is, for example, a step of uniaxially stretching a polyvinyl alcohol-based resin film; a step of adsorbing a dichroic dye by dyeing the polyvinyl alcohol-based resin film with a dichroic dye; polyvinyl having a dichroic dye adsorbed. It can be produced by a method including a step of treating an alcohol-based resin film with an aqueous boric acid solution; and a step of washing with water after the treatment with the aqueous boric acid solution.

The thickness of the splitter is preferably 50 μm or less, and more preferably 30 μm or less. Making the thickness of the polarizing element 30 μm or less is advantageous for reducing the thickness of the polarizing plate 100 and, by extension, the image display device. The thickness of the splitter is usually 2 μm or more (for example, 5 μm or more).

(2) Protective film The protective film that can be laminated on one or both sides of the polarizing element is a translucent (preferably optically transparent) thermoplastic resin, for example, a chain polyolefin resin (polypropylene resin). Etc.), Polyedic resin such as cyclic polyolefin resin (norbornen resin etc.); Cellulosic resin such as triacetyl cellulose, diacetyl cellulose; Polyester resin such as polyethylene terephthalate, Polybutylene terephthalate; Polycarbonate resin; (Meta) acrylic resin such as methyl methacrylate resin; polystyrene resin; polyvinyl chloride resin; acrylonitrile / butadiene / styrene resin; acrylonitrile / styrene resin; polyvinyl acetate resin; polyvinylidene chloride resin A film made of a polyamide resin; a polyacetal resin; a modified polyphenylene ether resin; a polysulfone resin; a polyether sulfone resin; a polyarylate resin; a polyamideimide resin; a polyimide resin or the like can be used. Above all, it is preferable to use a polyolefin-based resin or a cellulosic-based resin. In the present specification, the “(meth) acrylic resin” refers to at least one selected from the group consisting of acrylic resins and methacrylic resins. The same applies to other terms with "(meta)".

The thickness of the protective film is usually 1 to 100 μm, but is preferably 5 to 60 μm, more preferably 5 to 50 μm, from the viewpoint of strength, handleability, and the like.

At least one of the protective films has a hard coat layer, an antiglare layer, a light diffusing layer, and a retardation layer (with a retardation value of 1/4 wavelength) on its outer surface (the surface opposite to the polarizing element). It may be provided with a surface treatment layer (coating layer) such as a retardation layer), an antireflection layer, an antistatic layer, and an antifouling layer, or an optical layer.

The protective film can be attached to the polarizing element, for example, via an adhesive layer. As the adhesive forming the adhesive layer, a water-based adhesive, an active energy ray-curable adhesive, or a thermosetting adhesive can be used, and a water-based adhesive or an active energy ray-curable adhesive is preferable. ..

(3) Other Optical Film The polarizing plate 100 can include an optical film other than the polarizing element and the protective film, and typical examples thereof are a brightness improving film and a retardation film. When the polarizing plate 100 includes another optical film, the protect film 60 may be laminated on the surface of the optical film.

(4) First Adhesive Layer The first adhesive layer 31 is an adhesive layer arranged on the outermost surface of the polarizing plate 100, and a multilayer film is attached to an image display element (for example, a liquid crystal cell) or another optical member. Can be used to fit. The thickness of the first pressure-sensitive adhesive layer 31 can be 1 to 40 μm, but from the viewpoint of thinning the polarizing plate 100 and suppressing the dimensional change of the polarizing plate 100 while maintaining good processability, 3 It is preferably about 25 μm (for example, 3 to 20 μm, more preferably 3 to 15 μm). As the material of the first pressure-sensitive adhesive layer 31, the above description of the pressure-sensitive adhesive layer is applied as it is.

(5) Separate Film The separate film 70 is a film that is temporarily attached to protect the surface of the first pressure-sensitive adhesive layer 31 until it is attached to an image display element (for example, a liquid crystal cell) or another optical member. The separate film 70 is usually made of a thermoplastic resin film having a mold release treatment on one side, and the mold release treatment surface is bonded to the first pressure-sensitive adhesive layer 31. The thermoplastic resin constituting the separate film 70 can be, for example, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, or the like. The same separate film as above can be attached to the surface of the third pressure-sensitive adhesive layer 32 in order to temporarily protect the surface of the optical film such as the luminance improving film 50 until it is attached. The thickness of the separate film 70 is, for example, 10 to 100 μm. When the storage elastic modulus of the first pressure-sensitive adhesive layer 31 is 0.15 to 1 MPa, and the thickness of the separate film in direct contact with the first pressure-sensitive adhesive layer 31 is 50 μm or less, in the push-cutting step, the first pressure-sensitive adhesive layer 31 has a thickness of 50 μm or less. 1 The method of the present invention is preferably applied because the pressure-sensitive adhesive layer 31 often has minute irregularities.

(6) Protect film The protect film 60 is composed of a resin film 61 and a non-adhesive resin layer 62 or a second adhesive layer 62 laminated on the resin film 61. The protective film 60 is a film for protecting the surface of the polarizing plate 100, and usually has a non-adhesive resin layer after the polarizing plate with a protective film is attached to, for example, an image display element or another optical member. The 62 or the second pressure-sensitive adhesive layer 62 is peeled off and removed.

The resin constituting the resin film 61 is, for example, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, or a thermoplastic resin such as a polycarbonate resin. be able to. A polyester resin such as polyethylene terephthalate is preferable. The resin film 61 may have a single-layer structure or a multi-layer structure, but is preferably a single-layer structure from the viewpoint of ease of manufacture, manufacturing cost, and the like. Regarding the second pressure-sensitive adhesive layer 62, the above-mentioned description of the first pressure-sensitive adhesive layer 31 is quoted.

[Sheet film manufacturing equipment]
The single-wafer film manufacturing apparatus according to the present embodiment has a cutting portion for cutting a multilayer film having an adhesive layer to obtain a single-wafer film from the multilayer film. The cutting portion is arranged so as to be in contact with the push-cutting blade arranged so as to enter the multilayer film from the first surface of the multilayer film and the second surface of the multilayer film, and can receive the push-cutting blade that has entered the multilayer film. It is equipped with a blade receiving plate. The indentation elastic modulus of the blade receiving plate is 3.5 × ¹⁰⁹ Pa or less. As for the cut portion, the above description of the cutting device in the method for manufacturing a single-wafer film is applied as it is. For the multilayer film, the above description of the multilayer film in the method for producing a single-wafer film is applied as it is.

The single-wafer film manufacturing apparatus according to the present embodiment may include components other than the above-mentioned cut portion, for example, a multilayer film manufacturing section for manufacturing a multilayer film, or a multilayer film wound in a roll shape. Examples thereof include an unwinding section, a transport section for transporting a multilayer film or a sheet-fed film, a drying section for drying a multilayer film or a sheet-fed film, and the like.

[How to cut multilayer film]
The method for cutting a multilayer film according to the present embodiment is to cut the inside of the multilayer film from the first surface of the multilayer film until the cutting edge reaches the blade receiving plate arranged so as to be in contact with the second surface of the multilayer film. Includes a push-cutting step to penetrate and cut the multilayer film. The indentation elastic modulus of the blade receiving plate is 3.5 × ¹⁰⁹ Pa or less. As for the cutting method, the above description of the cutting step in the method for producing a single-wafer film is applied as it is.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[Multilayer film]
As the multilayer film to be cut, a cycloolefin polymer (COP) polarizing plate (SRD341 mass-produced original fabric) with a rectangular protective film having a long side length of 300 mm and a short side length of 200 mm was used. The COP polarizing plate with a protective film is, from the top, a protective film (58 μm), a TAC film as a protective film (25 μm), a PVA film as a splitter (25 μm), a COP film (23 μm), and a first pressure-sensitive adhesive layer (1st pressure-sensitive adhesive layer). 20 μm), a PET film (38 μm) as a separate film is laminated. One side of the protective film was adhesive, the other side was non-adhesive, and one side of the adhesive was in contact with the TAC film and bonded.

The first pressure-sensitive adhesive layer had a storage elastic modulus of 0.3 MPa at a temperature of 20 ° C. and an angular frequency of 1,000 radians / sec.

[Example 1]
The cutting device shown in FIG. 4 provided with the cutting blade member 21a shown in FIG. 5 was used. As the cutting blade 211a of the cutting blade member 21a, a Thomson blade (manufactured by Ogino Seiki Seisakusho Co., Ltd.) having a length in the longitudinal direction of 614 mm was used. As the blade receiving plate 22, a polyurethane sheet (manufactured by Tigers Polymer Co., Ltd., Typelen TR100-50, thickness 1 mm) having no surface layer laminated on the surface in contact with the multilayer film was used. The indentation elastic modulus of the blade receiving plate 22 was measured by the following method and found to be 6.4 × 10 ⁶ Pa. The tack value of the surface of the blade receiving plate 22 in contact with the multilayer film was measured by the following method and found to be 0.6N.

(Measurement of indentation modulus)
The indentation elastic modulus is a microhardness tester "H100SMC" (manufactured by Fisher Instruments), and a Vickers quadrangular pyramid diamond indenter with a facing angle of 136 ° is used as an indenter. Derived from. The load increase rate in the measurement was 300 mN / 20 seconds. The lower the indentation modulus, the softer the material.

(Measurement of tack value)
The evaluation of the tackiness indicating the adhesiveness of the material surface was carried out using a device according to the JIS T 9233-3.8.6 (2) Mihashi method. In each Example / Comparative Example, one test piece having a width of 20 mm and a length of 100 mm was collected. The surface of the adhesive disk (diameter 50 mm, thickness 14 mm, made of aluminum) was washed with hexane and dried at room temperature for 30 minutes. The above-mentioned adhesive disk was mounted on a "Picma Tack Tester (II) type" (manufactured by Toyo Seiki Seisakusho Co., Ltd.), and the adhesive disk was lowered by a test device to bring it into contact with a sample. After contacting with a load of 800 gf for 30 seconds in an environment of room temperature (23 ° C.), the mixture was pulled up at 300 mm / sec. The maximum value of the force generated when the adhesive disk and the sample were separated was used as the numerical value of the tack property in the measurement, and the same test was performed 5 times by changing the sample position, and the average value was obtained. The lower the value, the lower the adhesiveness and the less sticking during processing.

(Cut test)
A COP polarizing plate with a protective film was placed on the mounting table 23 so as to be in contact with the blade receiving plate 22. At this time, the PET film (58 μm) as the protective film was placed on the upper side, and the PET film (38 μm) as the separate film was placed on the lower side in the direction of contacting the blade receiving plate 22. Then, the cutting blade 211a is inserted into the COP polarizing plate with a protective film so that the speed on the surface of the protective film is 6.6 mm / s, and the cutting blade 211a is cut in a direction orthogonal to the absorption axis to be attached with the protective film. COP polarizing plate was divided into two equal parts.

(Evaluation of streak-like unevenness)
A cutting test was carried out on eight samples, and the presence or absence of streak-like unevenness in the vicinity of the cut surface on the surface of the cut piece divided into two equal parts was visually evaluated for the eight samples. The evaluation results are shown in Table 1.

[Example 2]
A cutting test was performed in the same manner as in Example 1 except that a polyurethane sheet (manufactured by Tigers Polymer Co., Ltd., Typelen TR100-70, thickness 1 mm) different from that of Example 1 was used as the blade receiving plate 22. The presence or absence of streak-like unevenness was evaluated. The evaluation results are shown in Table 1. The indentation elastic modulus of the blade receiving plate 22 used in Example 2 and the tack value of the surface in contact with the multilayer film were as shown in Table 1.

[Example 3]
As the blade receiving plate 22, the same polyurethane sheet as in Example 1 is used as a base material, and an acrylic film (Technoloy S001 manufactured by Sumitomo Chemical Co., Ltd., thickness 80 μm) is applied as a surface layer on the surface in contact with the multilayer film. A cutting test was conducted in the same manner as in Example 1 except that the laminated plates laminated through the film were used, and the presence or absence of streak-like unevenness was evaluated. The evaluation results are shown in Table 1. The indentation elastic modulus of the blade receiving plate 22 used in Example 3 and the tack value of the surface in contact with the multilayer film were as shown in Table 1.

[Example 4]
As the blade receiving plate 22, the same polyurethane sheet as in Example 2 is used as a base material, and an acrylic film (Technoloy S001 manufactured by Sumitomo Chemical Co., Ltd., thickness 80 μm) is applied as a surface layer on the surface in contact with the multilayer film. A cutting test was conducted in the same manner as in Example 1 except that the laminated plates laminated through the film were used, and the presence or absence of streak-like unevenness was evaluated. The evaluation results are shown in Table 1. The indentation elastic modulus of the blade receiving plate 22 used in Example 4 and the tack value of the surface in contact with the multilayer film were as shown in Table 1.

[Comparative Example 1]
A cutting test was conducted in the same manner as in Example 1 except that a polyvinyl chloride sheet (manufactured by Sumitomo Bakelite Co., Ltd., thickness 3000 μm) was used as the blade receiving plate 22, and the presence or absence of streak-like unevenness was evaluated. went. The evaluation results are shown in Table 1. The indentation elastic modulus of the blade receiving plate 22 used in Comparative Example 1 and the tack value of the surface in contact with the multilayer film were as shown in Table 1.

10, 10a, 10b, 10c, 10d multilayer film, 11 sheet-fed film, 20 cutting device, 21,21a, 21b push-cutting blade member, 22 blade receiving plate, 23 mounting table, 31 first adhesive layer, 60 protective film, 61 resin film, 62 second adhesive layer, 70 separate film, 100 polarizing plate, 101 first surface, 102 second surface, 211a, 211b push-cutting blade, 212a, 212b elastic body, 213a holding portion.

Claims (8)

A method for producing a single-wafer film, which comprises a cutting step of cutting a multilayer film having an adhesive layer to obtain a single-wafer film from the multilayer film.
In the cutting step, the push-cutting blade is made to enter the multilayer film from the first surface of the multilayer film until it reaches the blade receiving plate arranged so as to be in contact with the second surface of the multilayer film. Including a push-cutting step of cutting the multilayer film,
A method for manufacturing a single-wafer film, wherein the blade receiving plate has a indentation elastic modulus of 1.0 × 10 ⁶ Pa or more and 1.0 × 10 ⁹ Pa or less. The method for producing a single-wafer film according to claim 1 , wherein the blade receiving plate has a tack value of 0.001 N or more and 0.1 N or less on the surface of the multilayer film in contact with the second surface. The method for producing a single-wafer film according to claim 1 or 2 , wherein the multilayer film has a polarizing element. A single-wafer film manufacturing apparatus having a cutting portion for cutting a multilayer film having an adhesive layer to obtain a single-wafer film from the multilayer film.
The cutting portion is arranged so as to be in contact with the push-cutting blade arranged so as to be able to enter the multilayer film from the first surface of the multilayer film and the second surface of the multilayer film, and the push-cutting portion has entered the multilayer film. Equipped with a blade receiving plate that can receive the blade,
The blade receiving plate is a single-wafer film manufacturing apparatus having a indentation elastic modulus of 1.0 × 10 ⁶ Pa or more and 1.0 × 10 ⁹ Pa or less. The single-wafer film manufacturing apparatus according to claim 4 , wherein the blade receiving plate has a tack value of 0.001 N or more and 0.1 N or less on the surface of the multilayer film in contact with the second surface. A cutting method for cutting a multilayer film having an adhesive layer.
The push-cutting blade is inserted into the multilayer film from the first surface of the multilayer film until it reaches the blade receiving plate arranged so as to be in contact with the second surface of the multilayer film, and cuts the multilayer film. Including the push-cutting process
The blade receiving plate is a method for cutting a multilayer film having an indentation elastic modulus of 1.0 × 10 ⁶ Pa or more and 1.0 × 10 ⁹ Pa or less. The method for cutting a multilayer film according to claim 6 , wherein the blade receiving plate has a tack value of 0.001 N or more and 0.1 N or less on the surface of the multilayer film in contact with the second surface. The method for cutting a multilayer film according to claim 6 or 7 , wherein the multilayer film has a polarizing element.

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