JP2020149033A - Method for manufacturing cut film - Google Patents

Abstract

To provide a method for manufacturing a cut film formed with high dimensional accuracy even in a curve-shape having a small curvature radius.SOLUTION: The method for manufacturing a cut film, including the operation of cutting a film laminate using a cutting device including a cutting tool and capable of setting a cutting width comprises: the first step of cutting the laminate by relatively moving the cutting tool to the laminate while contacting the cutting tool to the end surface of the laminate; and the second step of setting the cutting width of the cutting device to zero and relatively moving the cutting tool to the laminate obtained by the first step along the cut end surface.SELECTED DRAWING: None

Description

The present invention relates to a method for producing a machined film.

As a method of processing the shape of the film, a method of cutting the end face of the film with a cutting tool has been proposed.

Japanese Unexamined Patent Publication No. 2015-072454

In recent years, with the diversification of film shapes, cutting with a curved shape having a small radius of curvature may be required.

An object of the present invention is to provide a method for producing a machined film capable of forming a curved shape having a small radius of curvature with high dimensional accuracy.

The present invention provides the following method for producing a machined film.
[1] A method for manufacturing a cut film, which includes an operation of cutting a laminated film of a film using a cutting device equipped with a cutting tool and capable of setting a cutting width.
The first step of performing cutting by moving the cutting tool relative to the laminated body while making contact with the end face of the laminated body.
A second step of setting the cutting width of the cutting device to zero and moving the cutting tool relative to the laminated body obtained in the first step along the machined end face is included.
A method for manufacturing a machined film.
[2] The manufacturing method according to [1], wherein the cutting tool has a cutting blade that rotates about a rotation axis.
[3] The manufacturing method according to [2], wherein in the first step and the second step, the cutting tool is moved in a state where the rotation axis is perpendicular to the main surface of the laminate.
[4] The manufacturing method according to any one of [1] to [3], wherein in the first step and the second step, the cutting tool is moved along a direction parallel to the main surface of the laminated body. ..
[5] The manufacturing method according to any one of [1] to [4], wherein in the second step, the cutting tool is relatively moved in the same movement path as in the first step.
[6] The manufacturing method according to any one of [1] to [5], wherein in the first step, the cutting tool is relatively moved along the end face of the laminated body two or more times.
[7] In the second step, the end face machined with respect to the laminate obtained in the first step at a moving speed equal to or lower than the final moving speed of the cutting tool in the first step. The manufacturing method according to [6], wherein the cutting tool is relatively moved along the above.
[8] The production method according to any one of [1] to [7], wherein the cut film has a U-shaped notch and / or a concave portion.
[9] The production method according to any one of [1] to [8], wherein the cut film is an optical laminated film.
[10] The production method according to [9], wherein the optical laminated film has a polarizing layer.
[11] The manufacturing method according to [9], wherein the optical laminated film has a touch sensor.
[12] The production method according to any one of [9] to [11], wherein the optical laminated film further has a front plate.
[13] The manufacturing method according to [12], wherein the front plate exhibits flexibility.

According to the present invention, it is possible to provide a method for manufacturing a machined film capable of cutting even a curved shape having a small radius of curvature with high dimensional accuracy.

It is the schematic which shows an example of a cutting film. It is the schematic which shows an example of the cutting apparatus used in the manufacturing method of this invention. It is schematic cross-sectional view explaining an example of the manufacturing method of the cutting film of this invention. It is a schematic top view explaining an example of the manufacturing method of the cutting film of this invention. It is the schematic sectional drawing which shows an example of an optical laminated film. It is the schematic which shows the moving path of a cutting tool and the design shape of a cutting film in an Example.

<Manufacturing method of cutting film>
The method for manufacturing a cutting film of the present invention (hereinafter, also abbreviated as "manufacturing method") is a laminated body of films (hereinafter, abbreviated) using a cutting device equipped with a cutting tool and capable of setting a cutting width. Includes the operation of cutting a "laminate").

[Cutting film]
In the present specification, the machined film means a film whose end face is machined. The machined film may be square or rounded in plan view. The rounded square shape means a shape in which one or more of the four corners of the square are rounded corners composed of curved lines. The square shape means a shape in which none of the four corners are rounded, such as a rectangle, a square, or a parallelogram. In the present specification, the end face is a plane perpendicular to the stacking direction of the laminated body, and includes a corner portion and a side surface of a through hole described later. In the present specification, the plan view means that the film is viewed from the thickness direction of the machined film. Further, in the present specification, a shape in which the curve has a radius of curvature on the outside in the plan view of the laminate and a shape in which the curve has a radius of curvature on the inside in the plan view of the laminate are also referred to as inner R and outer R, respectively.

When the plan-view shape of the cut film is rectangular, the length of the long side may be, for example, 10 mm or more and 2000 mm or less, preferably 1000 mm or more and 1800 mm or less. The length of the short side is, for example, 5 mm or more and 800 mm or less, preferably 10 mm or more and 500 mm or less, and more preferably 20 mm or more and 300 mm or less.

The radius of curvature of the rounded corners may be, for example, 0.1 mm or more and 20 mm or less, preferably 1 mm or more and 15 mm or less. The rounded corners may be either an inner R or an outer R.

The cut film may have a U-shaped notch and / or a concave portion at the outer edge portion, a through hole in the plane, or any of them in a plan view shape.

The concave portion has a shape that is recessed inward from the outer edge portion in a plan view, and the depth of the recess may be, for example, 0.1 mm or more, preferably 3 mm or more. On the other hand, the depth of the recess is usually 20 mm or less. The corners forming the concave portion may be rounded. The radius of curvature of the rounded corners forming the concave portion may be, for example, 0.1 mm or more and 20 mm or less, preferably 1 mm or more and 15 mm or less.

The U-shaped notch has a U-shaped concave portion in a plan view. The radius of curvature of the U-shaped portion of the U-shaped notch may be, for example, 5 mm or less, preferably 4 mm or less, and more preferably 2.5 mm or less. The depth of the U-shaped notch may be, for example, 0.1 mm or more and 20 mm or less, preferably 1 mm or more and 15 mm or less.

The radius of the through hole may be, for example, 0.1 mm or more and 50 mm or less, preferably 1 mm or more and 30 mm or less. The shape of the through hole is not particularly limited, and may be, for example, a perfect circle shape, an elliptical shape, or the like.

The thickness of the cut film is not particularly limited because it varies depending on the function required for the cut film, the application of the cut film, etc., but may be, for example, 25 μm or more and 1000 μm or less, preferably 100 μm or more and 500 μm or less. More preferably, it is 100 μm or more and 300 μm or less.

FIG. 1 is a diagram showing an aspect of the shape of the cut film in a plan view. The cut film 100 has a square shape with rounded corners in a plan view, and has a concave portion composed of rounded corners 101, 102, 104, 105, rounded corners 106, 107, 108, 109, and a U-shape. It has a notch 103.

The cut film may be an optical laminated film described later. The constituent members constituting the optical laminated film may be a front plate, a polarizing layer, an optical functional layer, an adhesive layer, a separator film, a protective film, a touch sensor panel, a back plate, and the like, and these constituent members are laminated. It may be a

[Cutting tools]
The cutting tool may be, for example, a cutting tool having a cutting blade that rotates about a rotation axis. Examples of such a cutting tool include an end mill and the like. The cutting device may include two or more cutting tools.

[Cutting equipment]
The cutting device usually includes a cutting tool for cutting the laminated body, a mounting table having a flat surface for mounting the laminated body, and a fixing jig for fixing the laminated body to the mounting table. .. The cutting device may have two or more cutting tools. The mounting table may be fixed to the cutting device or may be movably installed. The cutting device may be provided with means for relatively moving the cutting tool and / or the mounting table, for example, by numerical control. Examples of such a cutting device include a numerically controlled milling machine.

The cutting width can be set in the cutting device. When the cutting device is a numerically controlled milling machine, a CAD diagram of the movement path of the cutting tool and / or the mounting table is created, and the cutting width is set by inputting a program for relatively moving the cutting tool and / or the mounting table according to the CAD diagram. Can be set. The CAD diagram may have a shape that is a predetermined amount inside the outer shape of the laminated body of the film that is the object to be cut, for example. Further, when the cutting tool is relatively moved along the guide having a predetermined shape, the cutting width can be set by adjusting the shape of the guide. In addition, there may be a portion where the cutting width set in the cutting device and the width of the end face of the laminated body to be actually cut do not match. The end face of the laminated body means a surface perpendicular to the laminating direction of the laminated body.

[Laminate]
The laminated body is formed by laminating a plurality of films before cutting (hereinafter, also referred to as a film for cutting). The film for cutting may be formed by shearing a long film to a predetermined size with a cutting blade such as a Thomson blade. The number of films to be laminated may be, for example, 10 or more and 500 or less. The thickness of the laminated body in the laminating direction may be, for example, 1 mm or more and 50 mm or less.

[First step]
The first step is a step of performing a cutting process by moving the cutting tool relative to the laminated body while contacting the end face of the laminated body.

When the cutting tool is a cutting tool having a cutting blade that rotates around a rotation axis, the cutting tool is generally moved relative to the main surface of the laminate with the rotation axis perpendicular to the main surface of the laminate from the viewpoint of improving dimensional accuracy. .. The main surface of the laminated body means the surface when viewed from the laminating direction of the film.

When the cutting tool is a cutting tool having a cutting blade that rotates about a rotation axis, the cutting tool is generally relatively moved along a direction parallel to the main surface of the laminate from the viewpoint of improving dimensional accuracy. be able to. Variations in the amount of cutting of the laminate in a direction parallel to the main surface of the laminate tend to be suppressed.

In the first step, the cutting tool can be relatively moved once or twice or more along the end face of the laminate. Even when the cutting tool is relatively moved along the end face of the laminated body only once, the cutting process can be performed precisely so that the design dimensions can be obtained. When the cutting tool is moved relative to the end face of the laminate twice, the first time it is roughly cut (roughened) with respect to the design dimensions, and the second time it is precisely cut so that the design dimensions can be obtained. (Finishing) can be performed. The cutting width during rough machining may be, for example, 50 μm or more and 500 μm, preferably 100 μm or more and 300 μm or less, and the amount of increase in the cutting width during finish machining with respect to the cutting width during rough machining is, for example, 20 μm or more and 300 μm or less. Preferably, it can be set to 50 μm or more and 200 μm or less. In the finishing process, the moving speed of the cutting tool can be the same as or slower than the roughing process.

[Second step]
The second step is a step of setting the cutting width of the cutting device to zero and moving the cutting tool relative to the laminated body obtained by the first step along the machined end face. The cutting device is a numerically controlled milling machine, and a CAD diagram of the movement path of the cutting tool and / or the mounting table is created, and the cutting width is set by inputting a program for relatively moving the cutting tool and / or the mounting table according to the CAD diagram. If so, the cutting width can be set to zero by moving the cutting tool and / or the mounting table relative to each other according to the same CAD diagram. In addition, when the cutting width is set by adjusting the shape of the guide for relative movement along the cutting tool, the cutting width is set to zero by moving the cutting tool relative to the same guide. be able to.
The cutting tool is a cutting tool having a cutting blade that rotates around a rotation axis, and the cutting tool is placed so that the rotation axis is perpendicular to the main surface of the laminate and parallel to the main surface of the laminate. When the relative movement is performed along the direction, the cutting width can be set to zero by making the movement path of the rotation axis the same as the final movement path of the first step.

In the second step, it is preferable that the conditions such as the rotation speed and the moving speed of the cutting tool are the same as those in the first step. When the cutting process is performed twice or more in the first step, it is preferable to perform the second step under the same cutting conditions as those immediately before the second step.

When the cutting width is set to zero in the second step and the cutting tool is relatively moved along the cut end face, the cut end face may come into contact with the cutting tool in the first step. It does not have to be in contact.

In the present invention, even when uncut parts or dimensional variations occur in the first step, the cutting tool is relatively moved along the machined end face in the second step by setting the cutting width to zero. Since the end face that has not been sufficiently cut in the first step is sufficiently cut in the second step and the end face that has already been sufficiently cut in the first step is not cut, the dimensional accuracy is high. A machined film can be obtained. By performing the second step, the dimensional variation of the outer R and the inner R can be suppressed, and in particular, the dimensional variation of the inner R can be suppressed.

Further, it was found that when the film constituting the laminated body is an optical laminated film and the optical laminated film contains an adhesive layer, cutting chips tend to adhere to the end face of the laminated body. According to the present invention, even in the case of a laminated body of a film containing such an adhesive layer, cutting chips can be removed in the second step, so that the end face of the laminated body can be beautified.

In the second step, the cutting tool is moved relative to the laminate obtained in the first step along the machined end face at the same moving speed as the moving speed of the cutting tool in the first step. Can be done. In the first step, when the relative movement is performed twice or more along the end face of the laminated body, the second step is at the same speed as or less than the movement speed when the cutting tool is last relatively moved in the first step. The cutting tool can be moved relative to each other in the process.

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 to make it easier to understand each component, and the scale of each component shown in the drawings does not necessarily match the scale of the actual component.

[One Embodiment of the present invention]
An embodiment of the present invention will be described with reference to the drawings. In one embodiment of the present invention, the cutting device 10 shown in FIG. 2 is used. The cutting device 10 has an end mill 12 as a cutting tool for cutting the laminated body 11, a fixing jig 13 for fixing the laminated body 11 to the mounting table 14, and a flat surface for mounting the laminated body 11. It is provided with a mounting table 14 having the above. The cutting width of the cutting device 10 can be set.

The laminate 11 is a laminate of a plurality of films. The film may be formed by shearing a long film to a predetermined size with a cutting blade such as a Thomson blade. The film may be an optical laminated film described later.

As shown in FIG. 2, the dimensions of the fixing jig 13 and the mounting table 14 are made smaller than the dimensions of the laminated body 11, and the mounting and fixing are performed so that the end portion of the laminated body 11 protrudes from the fixing jig 13 and the mounting table 14. can do. By placing and fixing the laminated body 11 in this way, the end face 11a of the laminated body 11 can be cut by the end mill 12. Although not shown, the cutting device may have two or more end mills.

A holding member (for example, an acrylic resin sheet or the like) having the same or larger dimensions as the fixing jig 13 and the mounting table 14 can be installed between the fixing jig 13 and the mounting table 14 and the laminated body 11, respectively. .. This makes it possible to prevent damage to the laminated body 11 due to friction between the fixing jig 13 and the mounting table 14 and warpage of the laminated body 11.

The end mill 12 can be a rotating body about a rotation axis. Although the end mill 12 is shown as a cylindrical shape in FIG. 2, it is not limited to this shape. The end mill 12 may be an end mill provided in a numerically controlled milling machine.

The laminated body 11 can be fixed by sandwiching the fixing jig 13 and the mounting table 14 with, for example, a clamp tool, or the fixing jig 13 and / or the mounting table 14 can be moved up and down to fix the structure. It is also possible to fix the tool 13 and / or the mounting table 14 by moving it and sandwiching the laminated body 11.

Next, as shown in FIG. 3, in the first step, the end mill 12 is brought into contact with the end surface 11a of the laminated body 11 installed between the fixing jig 13 and the mounting table 14 and moved relative to the laminated body. The end face 11a of the laminated body 11 can be cut by the method (FIGS. 3 (a), 3 (b), 3 (c)). The end mill 12 can move the rotation axis relative to the main surface 11b of the laminated body in a state perpendicular to the main surface 11b. Further, the end mill 12 can be relatively moved along a direction parallel to the main surface 11b of the laminated body. The shape of the laminated body 11 when viewed from the laminating direction of the film, that is, the shape of the main surface 11b is shown as a square shape, but after cutting one side of the square shape, the cutting work is still performed. Not another side can be processed. Further, before cutting the laminated body 11 into a desired shape, the end face 11a can be roughly cut by the end mill 12. The cutting width is the distance W1 from the position A1 of the end face before cutting (FIGS. 3 (a) and 3 (b)).

In the second step, the end mill 12 is moved relative to the laminated body obtained in the first step along the machined end face 11c by setting the cutting width of the cutting device to zero (FIG. 3 (d). )). In FIG. 3, in order to set the cutting width of the cutting device to zero, the cutting width W1 and the cutting width W2 are set to be the same (FIGS. 3C and 3D). The end mill 12 can be relatively moved so that the movement paths of the rotation axes of the end mill 12 are the same when viewed from the stacking direction of the laminated body in the first step and the second step.

In the second step, the end mill 12 has a moving speed equal to or less than the moving speed of the end mill 12 in the first step, and is relative to the laminate obtained in the first step along the machined end face. Can be moved. When the end mill 12 is moved twice or more along the end face of the laminated body 11 in the first step, the moving speed is the same as or less than the moving speed when the end mill 12 is finally moved relative to each other in the first step. , The end mill 12 can be relatively moved in the second step.

The movement path of the cutting tool 21 when the cutting film 23 is manufactured according to one embodiment of the present invention will be described with reference to FIG. FIG. 4 is a view of the laminated body 21 showing an example of the moving path of the cutting tool 21 as viewed from the laminating direction. The machined film 23 has rounded corners 21a, 21b, 21c, 21e and a U-shaped notch 21d.

In FIG. 4, first, in the first step, the cutting tool 21 is brought into contact with the end face of the laminated body 21 (FIG. 4A). The contacted cutting tools 21 are relatively moved to form rounded corners 21a, 21b, 21c (FIGS. 4 (b), (c), (d)). Subsequently, while the cutting tool 21 is brought into contact with the end face of the laminated body, the cutting tool 22 is relatively moved as shown by the arrow in FIG. 4 (e) to form the U-shaped notch portion 21d. Finally, the rounded corner portion 21e is formed (FIG. 4 (f)).

In the second step, as shown in FIG. 4 (g), in the same path as the path in which the cutting tool 22 relatively moved in the first step (FIGS. 4 (a) to 4 (f)), that is, in FIG. 4 (g). The cutting film 24 is obtained by moving the cutting tool 22 relative to the laminated body 23 along the machined end face as shown by the arrow in the middle.

In FIG. 4E, when the cutting tool 22 is relatively moved as shown by an arrow when forming the U-shaped notch 21 portion d, the dimensional accuracy of the latter half of the curve may not be sufficiently obtained. Even in such a case, in FIG. 4 (g), the cutting tool 22 is relatively moved as shown by the arrow in the second step, so that the U-shaped notch 21d is formed in a desired size. A processed film will be obtained.

[Optical laminated film]
The constituent members constituting the optical laminated film may include a front plate, a polarizing layer, an optical functional layer, an adhesive layer, a separator film, a protective film, a touch sensor panel, a back plate, and the like, and these constituent members are laminated. It may be the one that has been done.

[Front plate]
The front plate is preferably a plate-like body capable of transmitting light. The front plate may be composed of only one layer, or may be composed of two or more layers.
Examples of the front plate include a glass plate (glass plate, flexible thin-walled glass, etc.), a resin plate (resin plate, resin sheet, resin film (sometimes referred to as a window film), etc.). ), And it is preferable that the plate-like body exhibits flexibility. Among the above, a plate-like body made of resin such as a resin film is preferable. Flexibility means that it can be repeatedly bent or bent.

Examples of the resin plate-like body include a resin film made of a thermoplastic resin. As the thermoplastic resin, a polyolefin resin such as a chain polyolefin resin (polyethylene resin, polypropylene resin, polymethylpentene resin, etc.), a cyclic polyolefin resin (norbornen resin, etc.); cellulose such as triacetyl cellulose Based resin; Polyester based resin such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate; Polycarbonate resin; Ethylene-vinyl acetate resin; Polystyrene resin; Polyamide resin; Polyetherimide resin; Polymethyl (meth) acrylate resin Etc. (Meta) acrylic resin; polyimide resin; polyether sulfone resin; polysulfone resin; polyvinyl chloride resin; polyvinylidene chloride resin; polyvinyl alcohol resin; polyvinyl acetal resin; polyether ketone resin ; Polyether ether ketone resin; polyether sulfone resin; polyamideimide resin and the like.
The thermoplastic resin can be used alone or in combination of two or more.
Among them, a polyimide resin, a polyamide resin, and a polyamide-imide resin are preferably used as the thermoplastic resin constituting the front plate from the viewpoint of flexibility, strength, and transparency.

The front plate may be a film having a hard coat layer provided on at least one surface of the base film to further improve the hardness. As the base film, the above-mentioned resin film can be used.

The hard coat layer may be formed on one surface of the base film or may be formed on both surfaces. By providing the hard coat layer, hardness and scratchability can be improved. The thickness of the hard coat layer may be, for example, 0.1 μm or more and 30 μm or less, preferably 1 μm or more and 20 μm or less, and more preferably 5 μm or more and 15 μm or less.

The hard coat layer is, for example, a cured layer of an ultraviolet curable resin. Examples of the ultraviolet curable resin include (meth) acrylic resin, silicone resin, polyester resin, urethane resin, amide resin, epoxy resin and the like. The hard coat layer may contain additives to improve strength. The additive is not limited, and examples thereof include inorganic fine particles, organic fine particles, and a mixture thereof.

The front plate may not only have a function of protecting the front surface (screen) of the display device, but may also have a function as a touch sensor, a blue light cut function, a viewing angle adjusting function, and the like.

The thickness of the front plate may be, for example, 20 μm or more and 2000 μm or less, preferably 25 μm or more and 1500 μm or less, more preferably 30 μm or more and 1000 μm or less, still more preferably 40 μm or more and 500 μm or less, particularly preferably 40 μm or more and 200 μm or less, and further preferably. It may be 40 μm or more and 100 μm or less.

[Polarizing layer]
The polarizing layer usually consists of a layer made of a polarizer and a protective film.
The polarizer is a polarizer containing a polyvinyl alcohol-based resin film, and may be, for example, a polarizer in which a dichroic dye is adsorbed and oriented on a uniaxially stretched polyvinyl alcohol-based resin film. The polarizer is an absorption type polarizing element having a property of absorbing linearly polarized light having a vibration plane parallel to the absorption axis and transmitting linearly polarized light having a vibration plane orthogonal to the absorption axis (parallel to the transmission axis). be able to. The polarizer can be used as a polarizing plate by attaching a protective film to one surface thereof with an adhesive, an adhesive, or the like.

The thickness of the polarizer is usually 30 μm or less, preferably 18 μm or less, and more preferably 15 μm or less. Reducing the thickness of the polarizer is advantageous for thinning the polarizing plate. The thickness of the polarizer is usually 1 μm or more, and may be, for example, 5 μm or more.

The thickness of the polarizer can be controlled, for example, by selecting a polyvinyl alcohol-based resin film, adjusting the draw ratio, or the like.

Examples of the protective film include a thermoplastic resin film.
Examples of the thermoplastic resin film include a cyclic polyolefin resin film, a cellulose acetate resin film made of a resin such as triacetyl cellulose and diacetyl cellulose, and a polyester film made of a resin such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. Examples of films known in the art such as resin films, polycarbonate-based resin films, (meth) acrylic-based resin films, and polypropylene-based resin films can be mentioned. From the viewpoint of thinning, the thickness of the thermoplastic resin film is usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, and usually 5 μm or more, 20 μm or more. Is preferable.

The thickness of the thermoplastic resin film is preferably thin from the viewpoint of thinning the polarizing plate, but if it is too thin, the strength tends to decrease and the processability tends to be inferior. Therefore, the thickness is preferably 5 μm or more and 150 μm or less, more preferably. It is 5 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less.

The thermoplastic resin film can also be a protective film having optical functions such as a retardation film and a brightness improving film. For example, a retardation film to which an arbitrary retardation value is given by stretching a transparent resin film made of the above material (uniaxial stretching, biaxial stretching, etc.) or forming a liquid crystal layer or the like on the film. Can be.
When the optical laminated film is arranged in the image display device, the optical laminated film can be attached to the image display device so that the thermoplastic resin film is on the image display device side.

The thermoplastic resin film may have a hard coat layer formed therein. The hard coat layer may be formed on one surface of the thermoplastic resin film, or may be formed on both surfaces. By providing the hard coat layer, a thermoplastic resin film having improved hardness and scratchability can be obtained. The hard coat layer is, for example, a cured layer of an ultraviolet curable resin. Examples of the ultraviolet curable resin include acrylic resin, silicone resin, polyester resin, urethane resin, amide resin, epoxy resin and the like. The hard coat layer may contain additives to improve strength. Additives are not limited, and examples thereof include inorganic fine particles, organic fine particles, and mixtures thereof.

[First adhesive layer]
The first pressure-sensitive adhesive layer can be interposed between the polarizing layer and the optical functional layer to bond them. The first pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive composition containing a polymer such as a (meth) acrylic resin, a rubber-based polymer, a urethane-based resin, an ester-based resin, a silicone-based resin, or a polyvinyl ether-based resin as a main component. be able to. 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 containing one or more (meth) acrylic acid esters such as ethylhexyl as a monomer is preferably used. The base polymer is preferably copolymerized with a polar monomer. Polar monomers include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, and glycidyl (meth). 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 acrylate.

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

To form the first pressure-sensitive adhesive layer, a pressure-sensitive adhesive composition is dissolved or dispersed in an organic solvent such as toluene or ethyl acetate to prepare a pressure-sensitive adhesive liquid, which is directly applied to the target surface of the laminate to provide a pressure-sensitive adhesive. It can be carried out by a method of forming a layer, a method of forming an adhesive layer in a sheet shape on a separate film subjected to a mold release treatment, and transferring the adhesive layer to a target surface of a polarizing plate.
The thickness of the first pressure-sensitive adhesive layer is determined according to its adhesive strength and the like, but may be, for example, in the range of 1 μm or more and 50 μm or less, preferably 2 μm or more and 40 μm or less, more preferably 3 μm or more and 30 μm or less, and further preferably. Is 3 μm or more and 25 μm or less.

The optical laminated film may include the above-mentioned separate film. The separate film can be a film made of a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate, or the like. Of these, a polyethylene terephthalate stretched film is preferable.

The first pressure-sensitive adhesive layer contains a filler composed of optional components, glass fibers, glass beads, resin beads, metal powder and other inorganic powders; pigments; colorants; antioxidants; ultraviolet absorbers; antistatic agents and the like. be able to.

Examples of the antistatic agent include ionic compounds, conductive fine particles, conductive polymers, and the like, and ionic compounds are preferably used.
The cation component constituting the ionic compound may be an inorganic cation or an organic cation.
Examples of the organic cation include pyridinium cation, imidazolium cation, ammonium cation, sulfonium cation, phosphonium cation, piperidinium cation, pyrrolidinium cation and the like, and examples of the inorganic cation include lithium ion and potassium ion.
On the other hand, the anion component constituting the ionic compound may be an inorganic anion or an organic anion, but an anion component containing a fluorine atom is preferable because it provides an ionic compound having excellent antistatic performance. Examples of the anion component containing a fluorine atom include hexafluorophosphate anion [(PF ₆ ⁻ )], bis (trifluoromethanesulfonyl) imide anion [(CF ₃ SO ₂ ) ₂ N ⁻ ] anion, and bis (fluorosulfonyl) imide anion [ (FSO ₂ ) ₂ N ⁻ ] anions and the like can be mentioned.

[Optical functional layer]
The optical functional layer may be an optical functional film other than the polarizer for imparting a desired optical function. A preferred example of an optically functional film is a retardation film. Examples of the retardation film include a film giving a phase difference of λ / 2 (λ / 2 wave plate), a film giving a phase difference of λ / 4 (λ / 4 wave plate), and a positive C plate. The optical functional film may include an alignment layer and a base material, or may have two or more liquid crystal layers, alignment layers, and a base material, respectively. When the optical laminated film has a polarizing layer and a film giving a phase difference of λ / 4, the optical laminated film may be a circular polarizing plate.
The thermoplastic resin film can also serve as a retardation film, but a retardation film can be laminated separately from these films.

The retardation film is a birefringent film composed of a stretched film of a translucent thermoplastic resin; a film in which a discotic liquid crystal or a nematic liquid crystal is oriented and fixed; the above liquid crystal layer is formed on a base film. The ones that have been made are mentioned.
The base film is usually a film made of a thermoplastic resin, and an example of the thermoplastic resin is a cellulosic ester resin such as triacetyl cellulose.

Examples of other optical functional films (optical members) that can be included in the optical laminated film are a condenser plate, a brightness improving film, a reflective layer (reflective film), a semi-transmissive reflective layer (semi-transmissive reflective film), and a light diffusing layer (a light diffusing layer). Light diffusion film) and the like. These are generally provided when the optical laminated film is a polarizing plate arranged on the back side (backlight side) of the liquid crystal cell.

[Second adhesive layer]
The optical laminated film has a second pressure-sensitive adhesive layer on the optical functional layer side. The second pressure-sensitive adhesive layer can be attached to an image display element or another optical member with an optical laminated film.

As for the pressure-sensitive adhesive, the pressure-sensitive adhesive composition, the thickness and the manufacturing method used for the second pressure-sensitive adhesive layer, the description described in the section of the first pressure-sensitive adhesive layer is cited. The description of the first pressure-sensitive adhesive layer is also cited for the separator film used for the second pressure-sensitive adhesive layer and any components that may be contained.

[Protect film]
The optical laminated film can include a protective film for protecting the surface thereof (typically, the surface of the thermoplastic resin film of the polarizing plate). After the polarizing plate is attached to, for example, an image display element or another optical member, the protective film is peeled off and removed together with the adhesive layer contained therein.

The protective film is composed of, for example, a base film and an adhesive layer laminated on the base film. The above description is cited for the pressure-sensitive adhesive layer.
The resin constituting the base film may 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 a thermoplastic resin such as a polycarbonate resin. it can. A polyester resin such as polyethylene terephthalate is preferable.

The thickness of the protective film is not particularly limited, but is preferably in the range of 20 μm or more and 200 μm or less. When the thickness of the base material is 20 μm or more, the strength tends to be easily imparted to the laminated body.

[Touch sensor panel]
The touch sensor panel is not limited as long as it is a panel having a sensor (that is, a touch sensor) capable of detecting the touched position. The detection method of the touch sensor is not limited, and touch sensor panels such as a resistive film method, a capacitance coupling method, an optical sensor method, an ultrasonic method, an electromagnetic induction coupling method, and a surface acoustic wave method are exemplified. Since the cost is low, a touch sensor panel of a resistive film type or a capacitive coupling type is preferably used.

As an example of a resistance film type touch sensor, a pair of substrates arranged opposite to each other, an insulating spacer sandwiched between the pair of substrates, and a transparent conductive film provided as a resistance film on the inner surface of each substrate. Examples thereof include a member composed of a film and a touch position detection circuit. In an image display device provided with a resistance film type touch sensor, when the surface of the front plate is touched, the opposing resistance films are short-circuited and a current flows through the resistance film. The touch position detection circuit detects the change in voltage at this time, and the touched position is detected.

An example of a capacitively coupled touch sensor is a member composed of a substrate, a transparent electrode for position detection provided on the entire surface of the substrate, and a touch position detection circuit. In an image display device provided with a capacitance coupling type touch sensor, when the surface of the front plate is touched, the transparent electrode is grounded via the capacitance of the human body at the touched point. The touch position detection circuit detects the grounding of the transparent electrode, and the touched position is detected.

The thickness of the touch sensor panel may be, for example, 5 μm or more and 2,000 μm or less, preferably 5 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

The touch sensor panel may be a member in which a touch sensor pattern is formed on a base film. The example of the base film may be the same as the example in the above description of the protective film. The thickness of the touch sensor pattern may be, for example, 1 μm or more and 20 μm or less.
As an optical laminated film having a touch sensor panel, for example, a laminate having a base material (preferably a front plate, more preferably a front plate exhibiting flexibility), a touch sensor, and a polarizing layer in this order, or a base material (preferably). Is a laminate having a front plate, more preferably a front plate exhibiting flexibility), a polarizing layer, and a touch sensor in this order.

[Back plate]
The back plate is preferably a plate-like body capable of transmitting light. The back plate may be composed of only one layer, or may be composed of two or more layers.
Similar to the front plate, the back plate includes, for example, a glass plate-like body (for example, a glass plate, a glass film, etc.) and a resin plate-like body (for example, a resin plate, a resin sheet, a resin film, etc.). Can be mentioned.
Among the above, from the viewpoint of flexibility of the laminated body and the display device including the laminated body, it is preferable to show flexibility, and a resin plate-like body showing flexibility is preferable. Examples of the resin plate-like body include a resin film made of a thermoplastic resin. For specific examples of thermoplastic resins, the description of the front plate is cited. The thermoplastic resin is preferably a cellulose-based resin, a (meth) acrylic-based resin, a cyclic polyolefin-based resin, a polyester-based resin, a polycarbonate-based resin, or the like.

The retardation layer formed by curing the polymerizable liquid crystal compound may be incorporated into the polarizing plate and the laminate in the form of having an alignment layer and / or a base film. The back plate may be a base film to which the above composition is applied.

The thickness of the back plate is preferably 15 μm or more and 200 μm or less, more preferably 20 μm or more and 150 μm or less, and further preferably 30 μm or more and 130 μm or less from the viewpoint of thinning the laminated body.

The optical laminated film will be described with reference to FIG. The optical laminated film 200 shown in FIG. 5 has a protective film 201, a polarizing layer 202, an adhesive layer 203, a retardation layer 204, an adhesive layer 205, and a separator film 206. The polarizing layer 202 has thermoplastic resin films 208 and 209 on both sides of the polarizing element 207, respectively. The retardation layer 204 includes a λ / 2 wave plate 210, an adhesive layer 211, and a λ / 4 wave plate 212. The optical laminated film 200 can be used as a circular polarizing plate by peeling off the separator film 206 and sticking it to the visible side of the image display device via the pressure-sensitive adhesive layer 205.

[Use of optical laminated film]
The optical laminated film can be used in various display devices. The display device is a device having a display element, and includes a light emitting element or a light emitting device as a light emitting source. Examples of the display device include a liquid crystal display device, an organic EL display device, an inorganic electroluminescence (hereinafter, also referred to as inorganic EL) display device, an electron emission display device (for example, an electric field emission display device (also referred to as FED), and a surface electric field emission display. Device (also called SED)), electronic paper (display device using electronic ink or electrophoresis element, plasma display device, projection type display device (for example, grating light valve (GLV) display device, digital micromirror device (DMD)) (Also referred to as), a piezoelectric ceramic display, and the like. The liquid crystal display device includes any of a transmissive liquid crystal display device, a transflective liquid crystal display device, and the like. These display devices include a two-dimensional image. It may be a display device for displaying a three-dimensional image, or a three-dimensional display device for displaying a three-dimensional image. The laminate can be particularly effectively used for an organic EL display device or an inorganic EL display device.

<Manufacturing example 1>
(Making a film for cutting)
A polarizing plate for end face processing provided with a (meth) acrylic resin film was produced by the following procedure. After immersing a polyvinyl alcohol film with an average degree of polymerization of about 2400 and a saponification degree of 99.9 mol% or more in pure water at 30 ° C., the weight ratio of iodine / potassium iodide / water is 0.02 / 2/100. It was immersed in an aqueous solution at 30 ° C. Then, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water of 12/5/100 at 56.5 ° C. Subsequently, the film was washed with pure water at 8 ° C. and then dried at 65 ° C. to obtain a polarizing film in which iodine was adsorbed and oriented on polyvinyl alcohol. The stretching was mainly carried out in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.3 times. The thickness of the polarizing film was 12 μm.

A thermoplastic resin (TAC) film made of triacetyl cellulose having a thickness of 20 μm is placed on one surface of the obtained polarizing film, and a thermoplastic resin (COP) film made of a cyclic olefin resin having a thickness of 50 μm is placed on the other side. Each of the bonded surfaces was subjected to corona treatment, and then bonded via a photocurable adhesive (epoxy-based photocurable adhesive) to obtain a polarizing plate.

Next, a protective film having a thickness of 53 μm was provided on the outer surface of the COP film of the obtained polarizing plate, a pressure-sensitive adhesive layer having a thickness of 5 μm was provided on the outer surface of the COP film, and a liquid crystal compound was further provided on the outer surface of the pressure-sensitive adhesive layer. Consists of a λ / 2 wave plate (thickness 2 μm) composed of a cured layer and an alignment film, an adhesive layer (thickness 5 μm), and a λ / 4 wave plate (thickness 2 μm) composed of a layer and an alignment film cured with a liquid crystal compound. The retardation films were laminated. Next, a pressure-sensitive adhesive layer (thickness 25 μm) was provided on the outer surface of the retardation film, and a separate film (thickness 38 μm) subjected to a mold release treatment was bonded to the outer surface of the pressure-sensitive adhesive layer. Then, it was cut into a size of 1031 mm × 588 mm to obtain a film for cutting.

<Example 1>
A laminate in which the cutting films obtained as described above were stacked was installed on a mounting table of a cutting device equipped with a numerically controlled end mill, a fixing jig, and a mounting table. The installed laminate was pressed from above with a fixing jig and fixed.

[First step]
Cutting (roughing) was performed by moving the end mill relative to the laminated body while keeping it in contact with the end face of the laminated body. Next, cutting (finishing) was performed by moving the end mill relative to the laminated body while bringing it into contact with the end face of the laminated body.

[Second step]
With respect to the obtained laminated body, the cutting width of the cutting device was set to zero, and the end mill was relatively moved along the machined end face to obtain a machined film. No cutting chips were found on the end faces of the laminate.

FIG. 6 shows the movement paths of the end mills in the first step and the second step of the first embodiment. The broken line 1 indicates the movement path of the end mill during rough machining in the first step, and the broken line 2 indicates the movement path of the end mill during finishing machining in the first step and the movement path of the end mill in the second step, and the solid line 3 Shows the design shape of the obtained machined film. Table 1 shows the difference (dimension difference) between the design radius of curvature of each curved portion A to H and the measured radius of curvature of the obtained cut film.

<Comparative example 1>
In Example 1, a machined film was obtained in the same manner except that the second step was not performed. No cutting chips were found on the end faces of the laminate. Table 1 shows the difference (dimension difference) between the design value and the measured value of each curved portion of the cutting film of FIG.

As shown in Table 1, in Example 1, the dimensional difference could be made smaller than that in Comparative Example 1. According to the present invention, it is understood that a machined film can be manufactured with high dimensional accuracy.

10 Cutting device, 11 Laminated body, 11a End face, 11b surface, 11c Machined end face, 12 Cutting tool, 13 Fixing jig, 14 Mounting stand, 21 Laminated body, 21a, 21b, 21c, 21e Rounded corners, 21d U-shaped notch, 22 end mill, 100 machined film, 101, 102, 104, 105, 106, 107, 108, 109 rounded corners, 103 U-shaped notch, 200 laminate, 201 polarizer, 202 thermoplastic Resin film, 203 polarizing layer, 204 first pressure-sensitive adhesive layer, 205 optical functional layer, 206 second pressure-sensitive adhesive layer.

Claims (13)

A method for manufacturing a cut film, which includes an operation of cutting a laminate of films using a cutting device equipped with a cutting tool and capable of setting a cutting width.
The first step of performing cutting by moving the cutting tool relative to the laminated body while making contact with the end face of the laminated body.
A second step of setting the cutting width of the cutting device to zero and moving the cutting tool relative to the laminated body obtained in the first step along the machined end face is included.
A method for manufacturing a machined film. The manufacturing method according to claim 1, wherein the cutting tool has a cutting blade that rotates about a rotation axis. The manufacturing method according to claim 2, wherein in the first step and the second step, the cutting tool is moved in a state where the rotation axis is perpendicular to the main surface of the laminate. The manufacturing method according to any one of claims 1 to 3, wherein in the first step and the second step, the cutting tool is moved along a direction parallel to the main surface of the laminated body. The manufacturing method according to any one of claims 1 to 4, wherein in the second step, the cutting tool is relatively moved in the same movement path as the first step. The manufacturing method according to any one of claims 1 to 5, wherein in the first step, the cutting tool is relatively moved along the end face of the laminated body two or more times. In the second step, at a moving speed equal to or lower than the final moving speed of the cutting tool in the first step, the laminated body obtained in the first step is cut along the end face. The manufacturing method according to claim 6, wherein the cutting tool is relatively moved. The manufacturing method according to any one of claims 1 to 7, wherein the cut film has a U-shaped notch and / or a concave portion. The manufacturing method according to any one of claims 1 to 8, wherein the cut film is an optical laminated film. The manufacturing method according to claim 9, wherein the optical laminated film has a polarizing layer. The manufacturing method according to claim 9, wherein the optical laminated film has a touch sensor. The manufacturing method according to any one of claims 9 to 11, wherein the optical laminated film further has a front plate. The manufacturing method according to claim 12, wherein the front plate is flexible.