KR20210126006A - Manufacturing method of optical film - Google Patents

Abstract

This invention provides the manufacturing method of the optical film which can suppress generation|occurrence|production of the crack of the optical film containing a polarizer, using an end mill. The manufacturing method of the cut optical film of this invention includes forming a workpiece|work by overlapping a plurality of optical films containing a polarizer, and a cutting process of cutting the said workpiece with an end mill, The film is configured so that the absorption axis directions of the polarizers of the film are in the same direction, and the side (A) of the work including the cutting start point by the end mill or the tangent line (B) of the work at the cutting start point (B) and the polarizer The angle formed by the absorption axis is 0° to 30° or 150° to 180°.

Description

Manufacturing method of optical film

The present invention relates to a method for manufacturing an optical film.

BACKGROUND ART Various optical films (eg, polarizing plates) are used in image display devices such as mobile phones and notebook personal computers to realize image display and/or to enhance the performance of the image display. In recent years, use of an optical laminated body is desired also for the instrument panel of an automobile, a smart watch, etc., and it is desired to process the shape of an optical laminated body into a desired shape. In the case of such processing, the end mill may cut the end face. While high-precision cutting is possible in cutting by an end mill, there is a tendency for cracks to occur in the optical film during cutting. In particular, the occurrence of cracks when the end mill is in contact with the surface to be machined, and the occurrence of cracks when cutting an optical film containing a film that is easily torn in a predetermined direction such as a polarizer, is a typical problem of cutting by an end mill. .

Japanese Patent Laid-Open No. 2007-187781 Japanese Laid-Open Patent Publication No. 2018-022140

The present invention has been made in order to solve the above conventional problems, and its main object is to provide a method for manufacturing an optical film capable of suppressing crack generation of an optical film including a polarizer while using an end mill.

The manufacturing method of the cut optical film of this invention includes forming a workpiece|work by overlapping a plurality of optical films containing a polarizer, and a cutting process of cutting the said workpiece|work with an end mill, The said workpiece|work is It is configured so that the absorption axis direction of the polarizer of the optical film is in the same direction, and the side (A) of the work including the cutting start point by the end mill or the tangent line (B) of the work at the cutting start point and the polarizer The angle formed by the absorption axis is 0° to 30° or 150° to 180°.

In one embodiment, the said manufacturing method includes cutting the outer peripheral surface of the said workpiece|work with the said end mill in the said cutting process.

In one embodiment, the said workpiece|work is substantially rectangular shape comprised by a long side and a short side, the absorption axis of the said polarizer and the said long side are parallel, and the said cutting start point is set on the said long side.

In one embodiment, the said workpiece|work has a substantially rectangular shape comprised by a long side and a short side, the absorption axis of the said polarizer and the said short side are parallel, and the said cutting start point is set on the said short side.

In one embodiment, a recess or a hole is provided on one side of the said short side, and the said cutting starting point is set on the other short side.

In one embodiment, the work has a hole, and in the cutting step, the inner peripheral surface of the hole is cut with the end mill, and the tangent (B') of the work at the cutting start point by the end mill and the corresponding The angle formed by the absorption axis of the polarizer is 0° to 30° or 150° to 180°.

In one embodiment, the said workpiece|work is substantially rectangular shape comprised by a long side and a short side, and the absorption axis of the said polarizer and the said long side are parallel.

In one embodiment, the said workpiece|work is substantially rectangular shape comprised by a long side and a short side, and the absorption axis of the said polarizer and the said short side are parallel.

According to another aspect of the present invention, there is provided a method of manufacturing a machined optical film set. The manufacturing method includes manufacturing a first optical film and a second optical film that are cut by the manufacturing method of the cut optical film, the absorption axis of the polarizer constituting the first optical film and the second optical film The first optical film and the second optical film are formed so that the absorption axes of the polarizers constituting the optical film can be disposed so as to be orthogonal to each other.

In one embodiment, the outer diameter of the said end mill is 10 mm or less.

In one embodiment, the angle of twist of the end mill is 0°.

According to the present invention, the occurrence of cracks in the optical film containing the polarizer can be suppressed while using the end mill by setting the cutting start point to a specific position with respect to the absorption axis direction of the polarizer of the optical film containing the polarizer. It is possible to provide a method for manufacturing a cut-processed optical film.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic perspective view for demonstrating an example of the cutting process of the optical film of this invention.
It is a schematic perspective view for demonstrating an example of the end mill used for the cutting in the manufacturing method of the optical film of this invention.
Fig. 3 (a) of Fig. 3 is a schematic cross-sectional view seen in the axial direction for explaining another example of a cutting means used for cutting in the method for producing an optical film of the present invention; Fig. 3(b) is a schematic perspective view of the cutting means of Fig. 3(a).
It is a schematic plan view explaining the cutting process which concerns on one Embodiment of this invention.
5(a) and 5(b) are schematic plan views for explaining cutting according to one embodiment of the present invention.
6(a) - FIG.6(d) of FIG. 6 are schematic plan views explaining the cutting process which concerns on one Embodiment of this invention.
7(a) and 7(b) of FIG. 7 are schematic plan views for explaining the cutting process which concerns on one Embodiment of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, although specific embodiment of this invention is described with reference to drawings, this invention is not limited to these embodiment. In addition, the drawings are schematically shown for easy viewing, and the ratios and angles of length, width, thickness, etc. in the drawings are different from the actual ones.

A. Manufacturing method of optical film

The manufacturing method of the cut optical film of this invention includes overlapping a plurality of optical films containing a polarizer to form a work, and cutting the outer peripheral surface of the work with an end mill. The work is configured such that the absorption axis directions of the polarizers of the plurality of optical films are respectively the same. In the present specification, the term 'same direction' includes a case in which the direction is substantially the same, and specifically includes a case where the angle formed by each direction is 0° to 5°.

A-1. work formation

A single polarizer may be sufficient as the optical film containing a polarizer, and the film containing a polarizer and another layer may be sufficient as it. As another layer, the protective layer which protects a polarizer, the layer comprised with arbitrary appropriate optical function layers, etc. are mentioned. In one embodiment, a polarizing plate is used as an optical film containing a polarizer. The polarizing plate may include a polarizer and a protective layer disposed on at least one side of the polarizer. Moreover, as a film containing a polarizer, you may use the laminated body of a polarizing plate, a surface protection film, and/or a separator. A surface protection film or a separator is laminated|stacked so that peeling is possible on a polarizing plate through arbitrary appropriate adhesives. As used herein, a 'surface protection film' is a film that temporarily protects a polarizing plate, and is different from a protective layer (a layer that protects a polarizer) included in the polarizing plate.

The polarizer is typically a resin film (eg, polyvinyl alcohol-based resin film) with swelling treatment, stretching treatment, dyeing treatment with a dichroic substance (eg, iodine, organic dye, etc.), crosslinking treatment, washing It is obtained by performing various processes, such as a process and a drying process. In general, the polarizer obtained through the stretching treatment has a characteristic that cracks easily occur, but according to the present invention, the optical film containing the polarizer can be cut while preventing cracks.

The thickness of the optical film including the polarizer is not particularly limited and an appropriate thickness may be employed depending on the purpose, for example, 20 μm to 200 μm. The thickness of the polarizer is also not particularly limited, and an appropriate thickness may be employed depending on the purpose. The thickness of the polarizer is typically about 1 µm to 80 µm, and preferably 3 µm to 40 µm.

The size of the optical film including the polarizer is not particularly limited and may be an appropriate size depending on the purpose. In one embodiment, the optical film containing a polarizer is rectangular shape including the side parallel to the absorption axis of a polarizer, the length of the side parallel to the absorption axis of a polarizer is 10 mm - 400 mm, The length of the other side is 10 mm - It is 500 mm. In the present specification, 'parallel' includes a case that is substantially parallel, and specifically includes a case where an angle between two directions is 0° to 5°.

1 : is a schematic perspective view for demonstrating a cutting process, and the workpiece|work 1 is shown in this figure. As shown in FIG. 1, the workpiece|work 1 which laminated|stacked two or more optical films is formed. The optical film is typically cut into any suitable shape at the time of forming the work. Specifically, the optical film may be cut in a rectangular shape, may be cut in a shape similar to a rectangular shape, or may be cut in an appropriate shape (eg, circular) according to the purpose. In the illustrated example, the optical film is cut into a rectangular shape, and the work 1 includes outer peripheral surfaces (cut surfaces) 1a and 1b facing each other and outer peripheral surfaces (cut surfaces) 1c and 1d orthogonal to them. . The work 1 is preferably clamped from the top and bottom by clamping means (not shown). The total thickness of the work is, for example, 8 mm to 100 mm, preferably 8 mm to 50 mm, more preferably 8 mm to 20 mm, still more preferably 9 mm to 15 mm, still more preferably about 10 mm. If it is such a thickness, damage by the impact at the time of pressurization by a clamping means or cutting can be prevented. The optical films are superimposed so that the work has this total thickness. The number of optical films constituting the work may be, for example, 10 to 500 (in one embodiment, 10 to 300; in another embodiment, 10 to 50). The clamp means (eg, a jig) may be made of a soft material or a hard material. When composed of a soft material, its hardness (JIS A) is preferably 20° to 80°, more preferably 60° to 80°, and its thickness is, for example, 0.3 mm to 5 mm. When hardness is too high, the impression by a clamp means may remain. When hardness is too low or too high, a positional deviation may arise by deformation|transformation of a jig|tool, and cutting precision may become inadequate.

A-2. cutting process

Next, the work 1 is cut by the end mill 20 . Cutting can be performed by bringing the cutting edge of the end mill into contact with the outer peripheral surface of the work 1 . The cutting may be performed over the entire perimeter of the outer peripheral surface of the work, or may be performed only at a predetermined position. In addition, with respect to the workpiece|work which has a hole part, you may cut the said inner peripheral surface by making the cutting edge of an end mill abut against the inner peripheral surface of the said hole part. As the end mill 20, a straight end mill can be used typically. In cutting, only the end mill may be moved, only a workpiece|work may be moved, and both an end mill and a workpiece|work may be moved.

2 and 3, the end mill 20 has a rotating shaft 21 extending in the lamination direction (vertical direction) of the work 1, and the outermost diameter of the main body rotating around the rotating shaft 21. and a cutting edge 22 configured as The cutting edge 22 may be configured as the outermost diameter twisted along the rotation axis 21 as shown in FIG. 2 (it may have a predetermined twist angle), and is substantially parallel to the rotation axis 21 as shown in FIG. 3 . It may be comprised so that it may extend in one direction (the torsion angle may be 0 degree). In addition, '0°' means substantially 0°, and includes a case where a slight angle is twisted due to a processing error or the like. When the cutting edge has a predetermined twist angle, the twist angle is preferably 70° or less, more preferably 65° or less, and still more preferably 45° or less. The cutting edge 22 includes a blade tip 22a, a rake surface 22b, and an escape surface 22c. The number of blades of the cutting edge 22 can be appropriately set as long as a desired number of contacts, which will be described later, is obtained. The number of blades in Fig. 2 is 3 and the number of blades in Fig. 3 is 2, but the number of blades may be 1, 4, or 5 or more. Preferably, the number of blades is two. With such a configuration, the rigidity of the blade is ensured, the pockets are secured, and the cutting chips can be discharged satisfactorily.

In one embodiment, the outer diameter of an end mill is 10 mm or less, Preferably they are 3 mm - 9 mm, More preferably, they are 4 mm - 7 mm. In addition, in the present specification, the term 'outer diameter of the end mill' refers to doubling the distance from the rotating shaft to the end of one blade.

The conditions of the cutting process can be appropriately set according to a desired shape. For example, the number of rotations of the end mill is preferably 1000 rpm to 60000 rpm, more preferably 10000 rpm to 40000 rpm. The feed rate (relative speed to the work) of the end mill is preferably 500 mm/min to 10000 mm/min, more preferably 500 mm/min to 2500 mm/min.

In the present invention, the angle between the side (A) of the workpiece including the cutting starting point by the end mill or the tangent (B) of the workpiece at the cutting starting point and the absorption axis of the polarizer is 0° to 30° or 150° Cutting is performed so that it is ~180°. Also, in the present specification, the angle formed by the side (A) or the tangent (B) and the absorption axis of the polarizer means an angle (horizontal angle) in a plan view. In addition, when referring to an angle in the present specification, unless otherwise specified, the angle includes both clockwise and counterclockwise angles.

A-2-1. cutting of the outer periphery

It is a schematic plan view explaining the cutting process which concerns on one Embodiment of this invention. In embodiment shown in FIG. 4, the outer peripheral surface of the workpiece|work 1 is cut with an end mill. In FIG. 4 , the work 1 has a substantially rectangular shape, and the cutting start point a is included in the side A of the work 1 . The cutting start point (a) is the point at which the end mill first comes into contact with the work 1, and after that, the end mill follows the cut surface (outer circumferential surface in FIG. move relatively. When cutting spans the entire circumference of the outer peripheral surface of the workpiece, the cutting start point (a) and the cutting end point may be at the same position. As described above, the angle between the side A and the absorption axis X of the polarizer is 0° to 30° or 150° to 180°. In the present invention, the cutting start point (a) is set on the side (A) where the angle formed by the absorption axis (X) of the polarizer is 0° to 30° or 150° to 180°, that is, the absorption axis (X) By setting the cutting start point (a) on the side that is parallel to the black side, it is possible to prevent cracks in the polarizer during cutting. The angle between the side (A) and the absorption axis (X) of the polarizer is preferably 0° to 20° or 160° to 180°, more preferably 0° to 10° or 170° to 180°, More preferably, they are 0 degrees - 5 degrees or 175 degrees - 180 degrees.

The shape of the work (that is, the optical film) can be any suitable shape. Examples of the shape of the work include, for example, a substantially rectangular shape as shown in FIG. 4 , a substantially polygonal shape, a substantially circular shape, and a substantially elliptical shape. In addition, the shape of a workpiece|work may be the shape which combined a straight line and a curve suitably, and the shape comprised with the several curve from which curvature differs. In addition, the above-mentioned work may not have a pure rectangular shape, polygonal shape, circular shape, elliptical shape, etc., and may have a shape in which an irregular portion is added to these shapes. In the present specification, for example, a rectangular shape to which a deformable portion is added is included in an 'approximately rectangular shape'. As a mold release part, for example, a convex part, a hole, etc. other than a recessed part as shown in FIG. 4 are mentioned. In addition, the shape similar to that which curved the rectangular part may be sufficient as the said workpiece|work.

As shown in FIG. 5 , when the workpiece has a curved shape, the cutting start point is the angle between the tangent line B of the workpiece 1 at the cutting start point a and the absorption axis of the polarizer 0 It can be set at a position that becomes ° to 30 ° or 150 ° to 180 °. Thus, by setting a cutting starting point, the crack of the polarizer at the time of a cutting process can be prevented. The angle between the tangent (B) and the absorption axis (X) of the polarizer is preferably 0° to 20° or 160° to 180°, more preferably 0° to 10° or 170° to 180°, More preferably, they are 0 degrees - 5 degrees or 175 degrees - 180 degrees. In addition, in the present specification, the term 'tangent to the workpiece' refers to a tangent line in the plan view of the workpiece.

When the outer edge of the workpiece has a vertex and/or a connection point between a straight line and a curve, it is preferable not to use the vertex and the connection point as the cutting start point, and a point more than 2mm away from the vertex and the connection point is the cutting starting point. It is more preferable to set it as, and it is still more preferable to make the point 5 mm or more apart as a cutting start point. In one embodiment, the point 20 mm or more away from the said vertex and this connection point becomes a cutting starting point. In another embodiment, the location 40 mm or more away becomes a cutting starting point. When the said vertex and this connection point are used as a cutting start point, there is a possibility that a burr may generate|occur|produce.

When the workpiece has a mold release portion, the cutting start point is preferably set at a location separated by 2 mm or more from the mold part, more preferably at a location separated by 4 mm or more. In one embodiment, the location 20 mm or more away from the said mold release part becomes a cutting start point. In another embodiment, the location 40 mm or more away becomes a cutting starting point. Moreover, when the shape of a workpiece|work is substantially rectangular, it is preferable to set a cutting start point on the side different from the side in which the mold part was provided. By not making a mold release part and the mold release part vicinity into a cutting start point, the crack of the polarizer at the time of a cutting process can be prevented.

In one embodiment, as shown in FIG.6(a), the workpiece|work 1A has the substantially rectangular shape comprised by the long side and the short side, the absorption axis X of the said polarizer and the said long side are parallel, and a cutting edge is on the said long side. The time point (a) is set. In the work 1A, as shown in Fig. 6(a), a recessed portion may be provided in a part of one short side, or a hole 11 may be provided in the vicinity of one short side as shown in Fig. 6(b). .

In another embodiment, as shown in FIG.6(c), the workpiece|work 1B has the substantially rectangular shape comprised by the long side and the short side, the absorption axis X of the said polarizer and the said short side are parallel, and a cutting edge is on the said short side. The time point (a) is set. In the work 1B, a recessed part may be provided in a part of one short side. When a recessed part is provided in a part of one short side, it is preferable to set the cutting start point (a) to the other short side. Moreover, as shown in FIG.6(d), the hole 11 may be provided in the vicinity of one short side of the workpiece|work 1B. Also in this case, it is preferable to set the cutting start point (a) to the other short side.

A-2-2. Inner peripheral cutting

It is a schematic plan view explaining the cutting process which concerns on one Embodiment of this invention. In the embodiment shown in FIG. 7, the workpiece|work 1A', 1B' has the hole part 11', and the inner peripheral surface of the hole part 11' is cut by an end mill. In the present embodiment, the angle between the tangent (B') of the workpiece (substantially the outer edge of the hole) at the cutting start point (a) and the absorption axis (X) of the polarizer is 0° to 30° or 150° to 180°. ° (preferably 0 ° to 20 ° or 160 ° to 180 °, more preferably 0 ° to 10 ° or 170 ° to 180 °, still more preferably 0 ° to 5 ° or 175 ° to 180 ° )am. In one embodiment, as shown in FIG.7(a), the workpiece|work 1A' has the substantially rectangular shape comprised by the long side and the short side, and the absorption axis X of the said polarizer and the said long side are parallel. In another embodiment, as shown in FIG.7(b), the workpiece|work 1B' has the substantially rectangular shape comprised by the long side and the short side, and the absorption axis X of the said polarizer and the said short side are parallel.

A-3. Applications of Machined Optical Films

The cut optical film obtained by the manufacturing method of the present invention can be used for a liquid crystal image display device, an organic EL image display device, and the like. In addition, the cut optical film may be suitably used in a rectangular image display unit typified by the personal computer (PC) or tablet terminal and/or a heterogeneous image display unit typified by an automobile instrument panel or a smart watch.

B. Manufacturing method of optical film set

In one embodiment, a method of manufacturing a machined optical film set is provided. This manufacturing method comprises manufacturing a first optical film cut by forming a first work (eg, the work 1A, the work 1A'), and a second work (eg, the work 1B); and forming a workpiece 1B') to manufacture a cut-processed second optical film. The first optical film and the second optical film may be manufactured according to the manufacturing method described in Item A above. In one embodiment, a 1st work|work, a 2nd work, and the optical film which comprises these work|works are substantially the same shape.

In one embodiment, in the manufacturing method of the cut optical film set, it is possible to arrange|position so that the absorption axis of the polarizer which comprises the said 1st optical film may be orthogonal to the absorption axis of the polarizer which comprises the said 2nd optical film To form a first optical film and a second optical film. More specifically, when the first optical film and the second optical film have substantially the same shape, and when these films are formed into a laminate of the same shape in plan view, the absorption axis of the polarizer of the first optical film and the absorption of the second optical film A first optical film and a second optical film are formed so that the axes may be orthogonal. In such an embodiment, the cutting starting point at the time of cutting a 1st workpiece|work turns into a position which does not correspond to the cutting starting point at the time of cutting a 2nd workpiece|work. In addition, in the present specification, 'orthogonal' includes a case that is substantially orthogonal, and specifically includes a case where an angle between two directions is 85° to 95°.

In one embodiment, also in the manufacturing method of the optical film set cut-processed, 1 A of 1st workpiece|works and the 2nd workpiece|work 1B are substantially rectangular shape comprised by a long side and a short side as mentioned above. It is preferable that the 1st work 1A, the 2nd work 1B, and the optical film which comprises these work have substantially the same shape.

Moreover, as shown to Fig.6 (a), (b), in 1 A of 1st workpiece|works, the absorption axis (X) and long side of the polarizer with which the optical film which comprises 1 A of 1st workpiece|works are equipped are parallel. When cutting 1 A of 1st workpiece|works, a cutting start point is set on the long side of 1 A of 1st workpiece|works. In one embodiment, a recessed part is provided in a part of one short side of 1 A of 1st workpiece|works. Moreover, the hole part may be provided in the vicinity of one short side of 1 A of 1st work pieces.

Moreover, as shown to FIG.6(c), (d), in the 2nd workpiece|work 1B, the absorption axis X and the short side of the polarizer with which the optical film which comprises the 2nd workpiece|work 1B is equipped are parallel. When cutting the 2nd workpiece|work 1B, a cutting start point is set on the short side of the 2nd workpiece|work 1B. In one embodiment, in the 2nd work|work 1B, a recessed part is provided in a part of one short side. When a recessed part is provided in a part of one short side, it is preferable to set a cutting start point to the other short side. Moreover, the hole part may be provided in the vicinity of one short side in the 2nd work 1B. Also in this case, it is preferable to set the cutting start point to the other short side.

The first work may be a first work 1A' having a hole, and the first optical film may be an optical film from which the inner peripheral surface of the hole is cut. In addition, the said 2nd workpiece|work may be 2nd workpiece|work 1B' which has a hole part, and the optical film by which the inner peripheral surface of the hole part was cut off may be sufficient as the 2nd optical film. It is preferable that the 1st workpiece|work 1A', the 2nd workpiece|work 1B', and the optical film which comprise these workpiece|works have substantially the same shape. Moreover, it is preferable that the holes formed in each workpiece|work have substantially the same shape, and are respectively formed in the same position (corresponding position) in a workpiece|work. In one embodiment, as shown to Fig.7 (a), the workpiece|work 1A' has the substantially rectangular shape comprised by the long side and the short side, and the absorption axis X of the said polarizer and the said long side are parallel. In another embodiment, as shown in FIG.7(b), the workpiece|work 1B' has the substantially rectangular shape comprised by the long side and the short side, and the absorption axis X of the said polarizer and the said short side are parallel.

In addition to the substantially rectangular shape, the said 1st workpiece|work and the 2nd workpiece|work may have a substantially polygonal shape, a substantially circular shape, a substantially elliptical shape, etc. In addition, the shape of a workpiece|work may be the shape which combined a straight line and a curve suitably, and the shape comprised with the several curve from which curvature differs. For example, a cutting-processed optical film set can be manufactured from the 1st workpiece|work of the shape shown in FIG.5(a), and the 2nd workpiece|work of the shape shown in FIG.5(b). Even when the first work and the second work have these shapes, it is preferable that the first work, the second work, and the optical film constituting these work have substantially the same shape.

According to the manufacturing method of the cut-processed optical film set of the present invention, two types of optical films can be manufactured in which the absorption axes of the polarizers are orthogonal to each other and can be disposed to face each other. The first optical film and the second optical film may be used in, for example, a liquid crystal display device, the first optical film is disposed on one side of a liquid crystal cell provided in the liquid crystal display device, and the second optical film is disposed on the other side It can be used to arrange the film.

Example

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.

[Example 1]

By a common method, in order from the visual recognition side, surface protection film (48 micrometers) / hard coat layer (5 micrometers) / cycloolefin type protective film (47 micrometers) / polarizer (5 micrometers) / cycloolefin type protective film The optical film (polarizing plate) which has the structure of (24 micrometers)/adhesive layer (20 micrometers)/separator was produced. The pressure-sensitive adhesive layer was prepared according to [0121] and [0124] of Japanese Patent Application Laid-Open No. 2016-190996. The obtained optical film was punched out in a shape similar to FIG. 4 (approximately about 140 mm in size x 65 mm in size). The direction of the absorption axis of the polarizer of each optical film was made parallel to the long side of the optical film, and a plurality of punched optical films were overlapped to obtain a work (total thickness of about 10 mm). In a state in which the obtained work was clamped with a clamp (jig), a cutting start point was set on the long side of the optical film, and the periphery was cut by end milling. The end mill had two blades and a twist angle of 0°. In addition, the feed rate (feed rate at the time of cutting a straight line part) of the end mill was 1000 mm/min, and the rotation speed was 25000 rpm.

During the cutting, no cracks occurred in the optical film.

[Example 2]

The direction of the absorption axis of the polarizer of each optical film is parallel to the short side of the optical film, and a plurality of punched optical films are overlapped to form a work (total thickness of about 10 mm), and the cutting start point is set on the short side of the optical film Other than that, it carried out similarly to Example 1, and performed the cutting process.

During the cutting, no cracks occurred in the optical film.

[Comparative Example 1]

Except having set the cutting start point on the short side of the optical film, it carried out similarly to Example 1, and cut the optical film. In this case, a crack occurred in the optical film when the end mill came into contact with the outer peripheral surface of the work at the start of cutting.

Industrial Applicability

The cut optical film of the present invention can be suitably used in a rectangular image display unit typified by a personal computer (PC) or tablet terminal, and/or a heterogeneous image display unit typified by an instrument panel or smart watch of a vehicle. .

1 work
20 end mill

Claims (15)

stacking a plurality of optical films containing a polarizer to form a work; and
A cutting process of cutting the workpiece with an end mill,
The work is configured such that the absorption axis directions of the polarizers of the plurality of optical films are in the same direction,
The angle between the side (A) of the workpiece including the cutting starting point by the end mill or the tangent (B) of the workpiece at the cutting starting point and the absorption axis of the polarizer is 0° to 30° or 150° to 180 °in,
A method for manufacturing a cut optical film. According to claim 1,
In the cutting process, the manufacturing method of the cut-processed optical film comprising cutting the outer peripheral surface of the work with the end mill. 3. The method of claim 2,
The method for manufacturing a cut optical film, wherein the workpiece has a substantially rectangular shape composed of a long side and a short side, the absorption axis of the polarizer and the long side are parallel to each other, and the cutting start point is set on the long side. 3. The method of claim 2,
The method of manufacturing a cut optical film, wherein the workpiece has a substantially rectangular shape composed of a long side and a short side, the absorption axis of the polarizer and the short side are parallel to each other, and the cutting start point is set on the short side. 5. The method of claim 4,
The manufacturing method of the optical film by which the cutting process was carried out, the recessed part or a hole part is provided in one side of the said short side, and the said cutting starting point is set on the other short side. According to claim 1,
The work has a hole,
In the cutting process, it comprises cutting the inner peripheral surface of the hole with the end mill,
The angle between the tangent line (B ') of the work at the starting point of cutting by the end mill and the absorption axis of the polarizer is 0° to 30° or 150° to 180°,
A method for manufacturing a cut optical film. 7. The method of claim 6,
The manufacturing method of the optical film processed by the said workpiece|work being a substantially rectangular shape comprised by a long side and a short side, and the absorption axis of the said polarizer and the said long side being parallel. 7. The method of claim 6,
The manufacturing method of the optical film by which the said workpiece|work was cut into the substantially rectangular shape comprised by a long side and a short side, and the absorption axis of the said polarizer and the said short side are parallel. By the manufacturing method of the optical film processed according to claim 1, comprising manufacturing the first optical film and the second optical film processed,
Forming the first optical film and the second optical film so that the absorption axis of the polarizer constituting the first optical film and the absorption axis of the polarizer constituting the second optical film are orthogonal to each other,
A method for manufacturing a machined optical film set. 10. The method of claim 9,
By the manufacturing method of the cutting-processed optical film of Claim 3, manufacturing the cutting-processed 1st optical film, and
The method for producing a cut optical film according to any one of claims 4 to 5, comprising producing a cut second optical film,
A method for manufacturing a machined optical film set. 10. The method of claim 9,
By the manufacturing method of the optical film processed according to claim 7, manufacturing a cutting processing of the first optical film, and
By the manufacturing method of the optical film processed according to claim 8, comprising manufacturing a processing second optical film,
A method for manufacturing a machined optical film set. 9. The method according to any one of claims 1 to 8,
The outer diameter of the end mill is 10 mm or less, the manufacturing method of the cut optical film. 12. The method according to any one of claims 9 to 11,
The outer diameter of the end mill is 10 mm or less, the manufacturing method of the cut-processed optical film set. 9. The method according to any one of claims 1 to 8,
The twist angle of the end mill is 0 °, the manufacturing method of the cut-processed optical film. 12. The method according to any one of claims 9 to 11,
A method for manufacturing a cut optical film set, wherein the torsion angle of the end mill is 0°.

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