KR20210143273A - Manufacturing method of optical film - Google Patents

Abstract

Provided is a method for manufacturing an optical film that includes drilling using an end mill, suppresses deterioration of the inner peripheral surface quality of a hole, and enables drilling with good dimensional accuracy. The manufacturing method of the drilling-processed optical film of this invention includes the drilling process of forming a workpiece|work by overlapping a plurality of optical films, and performing a drilling process on the said workpiece|work using an end mill, After drilling a foundation hole in the workpiece with an end mill in a cantilever state with one end in the direction held, the inner circumferential surface of the foundation hole is cut by an end mill in a cantilever state in which one end and the other end in the axial direction are maintained. includes doing

Description

Manufacturing method of optical film

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

Various optical films (eg, polarizing plates) are used in image display devices such as portable terminals and notebook-type personal computers to realize image display and/or to enhance the performance of the image display. In recent years, the use of image display is expanding, and the optical film of a shape different from a rectangular shape other than a general rectangular optical film is calculated|required. As one of the optical films of different shapes, there is an optical film comprising a hole. In manufacture of such an optical film, it is possible to drill a foundation hole using an end mill, and also to cut the inner peripheral surface of a foundation hole using an end mill, and to drill a hole of a predetermined size.

In the drilling process as described above, it is required that there is no deterioration in quality such as crack generation in the workpiece (optical film), and a hole excellent in dimensional accuracy is formed. In addition, from the viewpoint of manufacturing efficiency, etc., it is preferable to provide a work obtained by laminating as many optical films as possible for drilling, and even when the work is thickened in this way, it is required to form holes with high dimensional accuracy.

International Publication No. 2017/047510

The present invention has been made in order to solve the above conventional problems, and its main object includes drilling using an end mill, suppressing deterioration of the inner peripheral surface quality of the hole, and optically capable of drilling with good dimensional accuracy It is to provide the manufacturing method of a film.

The manufacturing method of the drilling-processed optical film of this invention includes the drilling process of forming a workpiece|work by overlapping a plurality of optical films, and performing a drilling process on the said workpiece|work using an end mill, In the said drilling process, an axis After drilling a foundation hole in the workpiece with an end mill in a cantilever state with one end in the direction held, the inner circumferential surface of the foundation hole is cut by an end mill in a cantilever state in which one end and the other end in the axial direction are maintained. includes doing

In one embodiment, when cutting the inner peripheral surface of the foundation hole, the other end of the end mill is held in contact with the support unit.

In one embodiment, the said support unit is comprised so that attachment or detachment is possible with respect to the said end mill.

In one embodiment, the support unit is movable in the axial direction of the end mill.

In one embodiment, the pressing pressure with respect to the end mill of the said support unit is 0.01 MPa or more.

In one embodiment, the other end of the said end mill is a tapered shape.

In one embodiment, the support unit includes a recess configured to receive the other end of the end mill.

In one embodiment, the angle of the bottom of the concave portion is the angle of the top of the other end of the end mill ±10°.

In one embodiment, the Vickers hardness of the said end mill is HV900-HV7000.

In one embodiment, the Vickers hardness of the part in which the said end mill in the said support unit abuts is HV45-HV800.

In one embodiment, the outer diameter in the outermost part of the said end mill is 6 mm or less.

According to another aspect of the present invention, a drilling apparatus is provided. This drilling apparatus includes a pair of clamps configured to clamp a workpiece, an end mill held at one end, and a support unit disposed opposite the end mill and configured to hold the other end of the end mill, the clamp includes a through hole penetrating the end mill in an axial direction, the through hole is composed of a small diameter portion and a large diameter portion located outside the small diameter portion, and the large diameter portion has a shape in which the diameter of the through hole increases toward the outside.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the optical film which suppresses the deterioration of the inner peripheral surface of a hole, and can drill with favorable dimensional accuracy can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic perspective view for demonstrating an example of the drilling process and drilling apparatus in one Embodiment of this invention.
It is a schematic sectional drawing for demonstrating an example of the drilling process and drilling apparatus in 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 optical film by which the drilling process of this invention was carried out includes the drilling process of forming a workpiece|work by overlapping a plurality of optical films, and performing a drilling process on the said workpiece|work using an end mill. In the drilling process, after drilling a foundation hole in the workpiece by means of an end mill in a cantilever state in which one end in the axial direction is maintained, the foundation hole is made by an end mill in a two-arm state in which one end and the other end in the axial direction are maintained. cut the inner peripheral surface of

A-1. formation of work

1 is a schematic perspective view for explaining a drilling process, the work W is shown in this figure. As shown in FIG. 1, the workpiece|work W which laminated|stacked the optical film multiple sheets is formed. The optical film is typically cut into any suitable shape when forming a 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 example of illustration, the optical film is cut|disconnected in rectangular shape.

2 is a schematic cross-sectional view illustrating a state in which a workpiece provided for drilling is set. The work W is preferably clamped from the top and bottom by the clamp 10 . 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 40 mm, still more preferably 9 mm to 30 mm, particularly preferably 9 mm to 20 mm. 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 may be composed of a soft material, may be composed of a hard material, or may be composed of a soft material and a hard material. When comprised from a soft material, the hardness (JIS A) becomes like this. Preferably it is 20 degree - 80 degree, More preferably, it is 60 degree - 80 degree. When the hardness is too high, a dent by the clamp may remain. If the hardness is too low or too thick, positional deviation may occur due to deformation of the clamp, resulting in insufficient drilling precision. The thickness of the clamp is, for example, 5 mm to 30 mm. When the clamp includes a soft material, the thickness of the layer made of the soft material is, for example, 0.3 mm to 5 mm.

In one embodiment, the clamp 10 includes a through hole 11 that axially penetrates the end mill. The end mill 20 may pass through the through hole 11 to drill a foundation hole in the work W. In one embodiment, the through-hole 11 of the clamp 10 has the small-diameter portion 11a and the large-diameter portion 11b located outside the small-diameter portion 11a (the side opposite to the side in contact with the workpiece W). ) is composed of Details will be described later in Section B.

In one embodiment, the said optical film contains a polarizer. 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 from 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 via 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. Generally, although the polarizer obtained through an extending|stretching process has the characteristic that a crack is easy to produce, according to this invention, the optical film containing a polarizer can be cut, preventing a crack.

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.

A-2. drilling process

Next, a hole is drilled in the work W with the end mill 20 . Drilling of the work can be performed by passing the end mill through the work while rotating the end mill. In one embodiment, as shown in Fig. 1(b), after drilling a foundation hole in the work by lowering the end mill, as shown in Fig. 1(c), the end mill is rotated and moved in the horizontal direction. Cut the inner peripheral surface of the foundation hole. In the present invention, a foundation hole is drilled in the work W by the end mill 20 in a cantilevered state. The end mill 20 in a cantilevered state is an end mill in a state in which one end 21 (shank side end) in the axial direction of the end mill 20 is held, and typically the upper end of the end mill 20 is held. do. In FIG. 1 , one end 21 of the end mill 20 is held by a holding part 40 . Further, in the present invention, the inner circumferential surface of the foundation hole is cut by the end mill 20 in a biceps state in which one end 21 (shank side end) and the other end 22 (blade side end) in the axial direction are held. The two-armed end mill is an end mill in which both ends in the axial direction are held, and typically the upper end and the lower end of the end mill are held.

According to the present invention, by cutting the inner circumferential surface of the foundation hole by the end mill in a bipedal state, shaking and bending of the end mill are prevented, and a hole having excellent inner circumferential quality can be drilled. Specifically, it is possible to prevent floatation of each layer constituting the optical film (eg, floatation of the surface protection film, floatation of the separator), delamination, cracks, and the like, and a hole having excellent inner peripheral surface quality can be drilled. Further, according to the present invention, a hole having excellent dimensional accuracy can be formed. Specifically, as the thickness of the conventional work increases, the dimensional deviation of the optical film has occurred within the work due to shaking and warping of the end mill, etc. However, according to the manufacturing method of the present invention, even if the thickness of the work is thickened as well as when the work is thin, Each optical film can be punched with excellent dimensional precision. Further, according to the present invention, when forming a small-diameter hole, even when a thin and low-strength end mill is used, drilling with excellent inner peripheral quality and excellent dimensional accuracy can be performed.

As shown in FIG. 1, the end mill 20 includes a rotating shaft extending in the lamination direction (vertical direction) of the work W, and a cutting edge configured as the outermost diameter of a main body rotating around the rotating shaft. As shown in FIG. 1, it is preferable that a cutting edge is comprised as the outermost diameter twisted along a rotation axis. The twist angle of the cutting edge is preferably 70° or less, more preferably 65° or less, and still more preferably 45° or less. The cutting edge includes a cutting edge, a rake face, and an escape face. The number of cutting edges can be appropriately set as long as a desired number of contacts, which will be described later, is obtained. Preferably, the number of blades is three. With such a configuration, the rigidity of the blade is ensured and the pockets are secured, so that the cutting chips can be discharged satisfactorily.

In one embodiment, the outer diameter of the end mill in the outermost part is 6 mm or less, Preferably they are 1 mm - 4 mm, More preferably, they are 1.6 mm - 3.7 mm. In addition, as used herein, the term 'outer diameter of the end mill' refers to doubling the distance from the rotating shaft to the tip of one blade.

The overall length of the end mill, the length of the shank and the length of the blade may be any suitable length depending on the thickness of the work. The overall length of the end mill is, for example, 20 mm to 90 mm, preferably 30 mm to 70 mm. The length of the shank portion of the end mill is, for example, 15 mm to 40 mm, preferably 20 mm to 30 mm. The length of the blade part of the end mill is, for example, 5 mm to 50 mm, preferably 15 mm to 40 mm. The length of each part of the end mill is preferably within the range in which drilling of the workpiece is possible, and the shorter one is preferable. By using a short end mill, it is possible to suppress the wobble, warp, etc. of the end mill and perform drilling with good dimensional accuracy and excellent inner peripheral quality.

The Vickers hardness of the end mill is preferably HV900 to HV7000, more preferably HV1000 to HV5000, still more preferably HV1200 to HV3000. Vickers hardness is measured by the test method prescribed|regulated to JIS Z2244:2009.

In one embodiment, as shown in FIG. 1, the other end 22 of the said end mill has a tapered shape. If an end mill having such a shape is used, drilling with excellent inner peripheral surface quality can be performed. The angle of the top and bottom of the other end of the end mill is preferably 10° to 170°, more preferably 15° to 100°, and still more preferably 20° to 60°.

The conditions of processing at the time of drilling a foundation hole can be set suitably according to a desired shape. For example, the rotation speed of the end mill at the time of drilling a foundation hole becomes like this. Preferably it is 1000 rpm - 60000 rpm, More preferably, it is 10000 rpm - 40000 rpm.

The same end mill may be sufficient as the end mill used when drilling a foundation hole, and the end mill used when cutting the inner peripheral surface of a foundation hole, and different end mills may be sufficient as it. In one embodiment, the end mill used when drilling a foundation hole is used for cutting of the inner peripheral surface of a foundation hole as it is (that is, foundation hole drilling and cutting of the inner peripheral surface of a foundation hole are performed without replacing|exchanging an end mill). In one embodiment, after drilling a foundation hole, before cutting the inner peripheral surface of a foundation hole, an end mill is once spaced apart from a workpiece|work, and an end mill is made to revolve. By doing in this way, the cutting chips adhering to the end mill can be removed by centrifugal force, and problems at the time of cutting the inner peripheral surface caused by the cutting chips can be prevented. The rotational speed of the end mill at the time of revolving is, for example, 10000 rpm - 70000 rpm, Preferably it is 20000 rpm - 60000 rpm. In addition, at the time of the removal of a cutting chip, you may spray air to an end mill.

In one embodiment, after drilling the foundation hole, the end mill is moved in a plane orthogonal to the axial direction (eg, horizontally moved), and the inner peripheral surface of the foundation hole is cut. By cutting the inner peripheral surface of the base hole, a hole having excellent inner peripheral surface quality can be formed. In another embodiment, without moving the end mill in-plane, the workpiece is moved in a plane orthogonal to the axial direction of the end mill, and the inner peripheral surface of the foundation hole is cut. In another embodiment, the end mill and the work are moved in a plane orthogonal to the axial direction of the end mill, and the inner peripheral surface of the foundation hole is cut. The cutting amount of the inner peripheral surface of the foundation hole can be any suitable cutting amount depending on the size of the desired hole or the like. In one embodiment, the cutting amount (cutting thickness) of the inner peripheral surface of a foundation hole becomes like this. Preferably they are 0.01 mm - 1 mm, More preferably, they are 0.02 mm - 0.7 mm, More preferably, they are 0.05 mm - 0.4 mm. The cutting of the inner peripheral surface of the foundation hole may be divided into a plurality of times. In one embodiment, it is divided into 2 times - 4 times, and said cutting amount is cut.

As described above, when cutting the inner peripheral surface of the foundation hole, the end of the end mill on the opposite side (the other end) to the side held at the time of drilling the foundation hole is additionally held. The other end of the end mill may be held by any suitable method. Examples of the holding method include a method of holding by a support unit disposed on one side (eg, below) of the work; a method of moving the chuck mechanism to engage the other end of the end mill by using the centrifugal force of the end mill; For example, a method of clamping the side of the end mill by a chuck mechanism capable of being pressurized by air or the like is exemplified.

In one embodiment, as shown in FIG.1(c), when cutting the inner peripheral surface of a foundation hole, the other end 22 of the end mill 20 abuts against the support unit 30, and is hold|maintained. The support unit is preferably configured to be detachable from the end mill. The other end of the end mill is held when the support unit is in its original state. As the method of holding by the support unit, for example, a method of pressing the support unit in the axial direction with an end mill; The other end of the end mill is twisted into the support unit, and the method of fixing the end mill and the support unit is mentioned. It is preferable that the said support unit rotates according to the rotation of the hold|maintained end mill.

In one embodiment, the support unit is configured to be movable in an axial direction of the end mill, typically in an up-down direction. The support unit configured in this way may be pressed against the other end of the end mill with a predetermined pressure to hold the other end of the end mill. Movement of the support unit may be performed by any suitable method. In one embodiment, the movement of the support unit may be performed by air pressure, hydraulic pressure, or the like. Preferably, the support unit is moved by air pressure. Although not shown, the support unit is connected to, for example, any suitable shaft, and can be moved by up-and-down movement of the shaft. In addition, the support unit may be configured to rotate freely by arranging a bearing in the connection portion between the support unit and the shaft, and the support unit may be configured to rotate according to the rotation of the held end mill.

The pressing pressure of the support unit against the end mill is preferably 0.01 MPa or more, more preferably 0.03 MPa to 1 MPa, still more preferably 0.05 MPa to 0.5 MPa, particularly preferably 0.1 MPa to 0.3 MPa. If it is within such a range, an appropriate frictional force can be generated between the other end of the end mill and the support unit, and the end mill can be maintained satisfactorily. Moreover, while maintaining the end mill favorably, abrasion, damage, etc. of the said end mill can be prevented.

Preferably, as shown in FIGS. 1 and 2 , the support unit 30 includes a recess 31 . The recess 31 may be configured to receive the other end 22 of the end mill 20 . By providing the concave portion in the support unit, it is possible to prevent wobbling, warping, etc. of the end mill, and it is possible to drill a hole of particularly excellent quality on the inner circumferential surface with good dimensional accuracy. Further, the configuration including the concave portion is advantageous also in that the positioning of the other end of the end mill can be reliably performed, whereby a hole having excellent quality on the inner peripheral surface can be drilled with good dimensional accuracy. The shape of the concave portion may be any suitable shape to match the shape of the other end of the end mill. For example, when the other end of the end mill has a tapered shape, the concave portion may also have a tapered shape. It is preferable that the angle of the bottom of the recess is ±10° of the angle of the top of the other end of the end mill, (the angle of the top of the other end of the end mill -5°) to (the angle of the top of the other end of the end mill +8°) More preferably, it is more preferably (the top angle of the other end of the end mill -1°) to (the top angle of the other end of the end mill +5°), and the top angle of the other end of the end mill is ±1° It is particularly preferred. With such a range, positioning of the other end of the end mill can be performed with high accuracy, and the end mill can be held with excellent holding force.

In one embodiment, it is preferable that the diameter of the opening part of the recessed part 31 is smaller than the outer diameter of the outermost part of the end mill 20. As shown in FIG. The difference between the diameter of the opening of the concave portion and the outer diameter of the outermost portion of the end mill (the outer diameter of the outermost portion of the end mill 20 - the diameter of the opening of the concave portion 31) is preferably 0.1 mm to 4 mm, more preferably 0.5 mm to 2 mm. In another embodiment, the diameter of the opening part of the recessed part 31 is the same as the outer diameter of the outermost part of the end mill 20. As shown in FIG. In another embodiment, the diameter of the opening of the concave portion 31 is larger than the outer diameter of the outermost portion of the end mill 20 .

The Vickers hardness of the portion in the support unit that the end mill is in contact with (eg, the inner surface of the concave portion of the support unit) is preferably HV45 to HV800, more preferably HV80 to HV700, still more preferably HV200 to HV600 am. In such a range, it is possible to prevent wear and damage of the end mill. It is preferable that the Vickers hardness of the portion in contact with the end mill in the support unit is smaller than the Vickers hardness of the end mill. The Vickers hardness of the portion in contact with the end mill in the support unit is preferably 1% to 80%, more preferably 8% to 70%, and still more preferably 17% to Vickers hardness of the end mill. 50%. If it is within such a range, abrasion, damage, etc. of an end mill can be prevented.

In one embodiment, the support unit 30 is configured to be movable in a plane orthogonal to the axial direction of the end mill. When the end mill is moved in a plane perpendicular to the axial direction (eg, horizontally moved) and the inner circumferential surface of the foundation hole is cut, it is preferable to move the support unit 30 in-plane in conjunction with the end mill.

The conditions of processing when cutting the inner peripheral surface of the foundation hole can be appropriately set according to a desired shape. For example, the rotation speed of the end mill at the time of cutting the inner peripheral surface of a foundation hole becomes like this. Preferably it is 1000 rpm - 60000 rpm, More preferably, it is 10000 rpm - 40000 rpm. The feed speed (relative speed with respect to the work) of the end mill is preferably 10 mm/min to 5000 mm/min, more preferably 50 mm/min to 1000 mm/min.

After the cutting of the inner peripheral surface of the foundation hole is finished, the end mill retreats to one end side of the end mill (shank portion side) to separate it from the work. At this time, the support unit 30 may move in a direction opposite to the retraction direction of the end mill, that is, away from the end mill in the axial direction.

B. Drilling device

1 and 2, the drilling apparatus of the present invention includes a pair of clamps 10, an end mill 20 in which one end 21 is held, and the other end of the end mill 20 ( 22) is provided with a support unit 30 configured to be maintainable. The drilling apparatus of the present invention can be used, for example, for the drilling process of the workpiece W (laminate of optical films) as described in section A above.

The clamp 10 is configured such that the work W can be clamped. The clamp 10 includes a through hole 11 through the end mill 20 in the axial direction.

In one embodiment, the through-hole 11 of the clamp 10 has a small-diameter portion 11a and a large-diameter portion ( 11b). In the large-diameter portion 11b, the through-hole 11 has a shape in which the diameter thereof increases toward the outside.

The diameter of the small-diameter portion 11a is preferably (end mill diameter +0.1 mm) to (end mill diameter +5 mm), more preferably (end mill diameter +0.3 mm) to (end mill diameter +1 mm). .

The shape of the large-diameter portion 11b may be determined according to the shape of the holding portion 40 holding one end 21 of the end mill 20 on the side that becomes the inlet of the end mill 20 . On the side that becomes the inlet of the end mill 20, the shape of the large-diameter portion 11b is preferably such that at least a part of the holding portion 40 is inserted into the large-diameter portion 11b. The shape of the large diameter portion 11b may be determined according to the shape of the support unit 30 on the side that is the outlet of the end mill 20 . On the side that becomes the exit of the end mill 20, the shape of the large-diameter portion 11b is preferably such that at least a part of the support unit 30 is inserted into the large-diameter portion 11b. If the large-diameter portion 11b has such a shape, it becomes possible to use an end mill having a short overall length, and it is possible to prevent the end mill from shaking, warping, and the like. As a result, in the drilling apparatus of this invention, it is excellent in inner peripheral surface quality, and the drilling excellent in dimensional accuracy can be performed.

The configuration of the end mill 20 is as described in section A above.

Drilling apparatus 100 is configured to be able to cut the inner peripheral surface of the foundation hole drilled in the work (W). Specifically, the end mill 20 and/or clamp 10 is configured to move in a plane orthogonal to the axial direction of the end mill, and by in-plane movement of the end mill 20 and/or clamp 10, The inner peripheral surface of the foundation hole may be cut.

The support unit 30 may be disposed to face the end mill 20 . The configuration of the support unit 30 is as described in section A above.

Example

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

[Example 1]

Separator (38 μm) / adhesive layer (15 μm) / acrylic protective film (20 μm) / polarizer (5 μm) / brightness enhancement film (26 μm) / surface protection film ( An optical film (polarizing plate) having a structure of 60 µm) 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 that of FIG. 1 (approximately 140 mm in size x 65 mm in size). A plurality of punched optical films were superimposed on each other to obtain a work (total thickness of about 20 mm). As shown in FIG. 1, in the state which clamped the obtained workpiece|work, the foundation hole was drilled with the end mill (length of blade part 30mm, diameter 2mm). After that, as shown in FIG. 1, the end mill on the blade side of the end mill is held as a support unit, the end mill is moved in the horizontal direction, and the inner peripheral surface of the foundation hole is divided into two cuts (cutting amount per turn 0.1 mm), A hole having a diameter of 2.5 mm was formed. In addition, the support unit was pressed against the end mill with an air pressure and a pressing pressure of 0.15 MPa.

(evaluation)

Drilling is performed as in Examples and Comparative Examples for 10 workpieces, and for each workpiece (optical film) after processing, a total of 3 polarizing plates are taken out, one each from the upper side, the middle part, and the lower side, and 30 polarizing plates For (3 sheets x 10 work pieces), the presence or absence of floating|lifting of the surface protection film in a hole part, floating|lifting of a separator, and delamination between a polarizer/protective film was confirmed.

As a result, there was no sample in which floating of the surface protection film was confirmed at a width of 500 µm or more, and there was no sample in which floating of the separator and delamination were confirmed.

Further, a total of three polarizing plates were taken out one by one from the upper side, the middle part, and the lower side, and for each polarizing plate, the dimensional accuracy of the inner peripheral surface of the hole was measured by a CNC image measurement system (manufactured by Nikon Corporation, trade name 'NEXIV'). . As a result, in any sample, an optical film was obtained with dimensional accuracy within ±0.05 mm from the standard value.

[Example 2]

Drilling was performed in the same manner as in Example 1 except that the pressing pressure of the support unit was set to 0.1 MPa.

(evaluation)

Evaluation similar to Example 1 was performed. As a result, there was no sample in which floating of the surface protection film was confirmed at a width of 500 µm or more, and there was no sample in which floating of the separator and delamination were confirmed. In addition, the dimensional accuracy was able to meet the standard value within ±0.05mm.

[Comparative Example 1]

Drilling was performed in the same manner as in Example 1, except that the inner peripheral surface of the foundation hole was cut without holding the edge of the end mill on the blade side.

(evaluation)

Evaluation similar to Example 1 was performed. As a result, floating|lifting of the surface protection film and the floating|lifting of a separator were confirmed with the width|variety of 500 micrometers or more, and delamination was confirmed with the width|variety of 100 micrometers or more. Also, the dimensional accuracy could not satisfy the standard value ±0.05mm.

Industrial Applicability

The drilling-processed optical film of this invention can be used suitably for the rectangular image display part represented by a portable terminal, and/or the heteromorphic image display part represented by the instrument panel or smart watch of a car.

10 clamp
20 end mill
30 support units

Claims (12)

stacking a plurality of optical films to form a work; and
Including a drilling process of performing a drilling process on the work using an end mill,
The drilling process is
After drilling a foundation hole in the workpiece by an end mill in a cantilever state with one end in the axial direction held,
Including cutting the inner peripheral surface of the foundation hole by an end mill in a bipedal state in which one end and the other end in the axial direction are maintained,
A method for manufacturing a drilled optical film. According to claim 1,
When cutting the inner peripheral surface of the foundation hole, the other end of the end mill is held in contact with the support unit, the manufacturing method of the drilled optical film. 3. The method of claim 2,
The method of manufacturing a drilling-processed optical film, the support unit is configured to be detachable with respect to the end mill. 4. The method of claim 2 or 3,
The support unit is movable in the axial direction of the end mill, a method of manufacturing a drilled optical film. 5. The method according to any one of claims 2 to 4,
The manufacturing method of the drilling-processed optical film whose pressing pressure with respect to the end mill of the said support unit is 0.01 MPa or more. 6. The method according to any one of claims 2 to 5,
The method for manufacturing a drilled optical film, wherein the support unit includes a recess configured to receive the other end of the end mill. 7. The method according to any one of claims 2 to 6,
The Vickers hardness of a portion in contact with the end mill in the support unit is HV45 to HV800, a method of manufacturing a drilling-processed optical film. 8. The method according to any one of claims 1 to 7,
The other end of the end mill is a tapered shape, the manufacturing method of the drilling-processed optical film. 9. The method of claim 8 citing claim 6,
The manufacturing method of the drilling-processed optical film whose bottom angle of the said recessed part is the top angle of the other end of the said end mill ±10 degree. 10. The method according to any one of claims 1 to 9,
The Vickers hardness of the end mill is HV900 ~ HV7000, the manufacturing method of the drilling-processed optical film. 11. The method according to any one of claims 1 to 10,
The manufacturing method of the drilling-processed optical film whose outer diameter in the outermost part of the said end mill is 6 mm or less. A pair of clamps configured to clamp a workpiece, an end mill having one end held therein, and a support unit disposed opposite the end mill and configured to hold the other end of the end mill;
The clamp includes a through hole through the end mill in the axial direction,
The through hole is composed of a small-diameter portion and a large-diameter portion located outside the small-diameter portion,
The large-diameter portion has a shape in which the diameter of the through-hole increases toward the outside,
drilling device.

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