KR20210125487A - 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 unnecessary recessed part in an edge part while using an end mill. The manufacturing method of the optical film processed by cutting includes forming a workpiece by overlapping a plurality of optical films, and cutting the workpiece with an end mill, and at the start of cutting, from an oblique direction with respect to the workpiece in a planar view, the end This includes bringing the end mill into contact with the work while the mill is running, or separating the end mill from the work while running the end mill in an oblique direction with respect to the work in a planar view at the end of cutting.

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. In cutting with an end mill, high-precision cutting is possible, while at the beginning of cutting, a minute concavity is formed when the end mill is in contact with the surface to be machined, or when the end mill is removed from the surface to be machined, At the time of placement, there may be small steps or burrs. In recent years, high shape precision of an optical film is calculated|required, and suppression of generation|occurrence|production of such a recessed part, a level|step difference, a burr, etc. is calculated|required.

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

The present invention has been made to solve the above conventional problems, and its main purpose is to suppress the occurrence of unnecessary concavities, steps, burrs, etc. at the cutting start point and/or cutting end point while using an end mill, It is to provide the manufacturing method of an optical film.

The manufacturing method of the optical film processed by cutting includes forming a workpiece by overlapping a plurality of optical films, and cutting the workpiece with an end mill, and at the start of cutting, from an oblique direction with respect to the workpiece in a planar view, the end Contacting the end mill with the work while the mill is running, and/or separating the end mill from the work while running the end mill in an oblique direction with respect to the work in a planar view at the end of cutting include that

In one embodiment, the traveling trajectory ts of the said end mill at the time of a cutting start is curved.

In one embodiment, the radius of curvature of the traveling trajectory ts of the end mill at the start of cutting is larger than 1/2 of the outer diameter of the end mill.

In one embodiment, the radius of curvature of the traveling trajectory ts of the end mill at the start of cutting is larger than the outer diameter of the end mill.

In one embodiment, the traveling trajectory te of the end mill at the time of the end of the cutting is curved.

In one embodiment, the radius of curvature of the travel trajectory te of the end mill at the end of the cutting is greater than 1/2 of the outer diameter of the end mill.

In one embodiment, the radius of curvature of the travel trajectory te of the end mill at the end of the cutting is larger than the outer diameter of the end mill.

In one embodiment, the speed of the said end mill when the said end mill is brought into contact with the said work is slower than the feed speed of the said end mill when cutting the outer peripheral surface of the said work with the said end mill.

In one embodiment, the speed of the said end mill when separating the said end mill from the said work is slower than the feed speed of the said end mill when cutting the outer peripheral surface of the said work with the said end mill.

In one embodiment, cutting is performed over the entire periphery of the outer peripheral surface of the workpiece, the cutting start point (a) and the cutting end point (b) are set to different positions, and the running direction of the end mill is forward from the cutting start point (a) The cutting end point (b) is set in .

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°.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the optical film which can suppress generation|occurrence|production of unnecessary recesses, steps, burrs, etc. at a cutting start point and/or a cutting end point while using an end mill can be provided.

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).
4(a) and 4(b) are schematic plan views for explaining cutting according to one embodiment of the present invention.
5(a) and 5(b) are schematic plan views for explaining cutting according to one embodiment of the present invention.
It is a schematic plan view explaining the workpiece|work in 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.
8(a) and 8(b) of FIG. 8 are schematic plan views for explaining the cutting process according to one embodiment of the present 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.

The manufacturing method of the cut optical film of this invention includes overlapping a plurality of optical films to form a work, and cutting the outer peripheral surface of the work with an end mill.

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 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, and the thickness is 0.3 mm - 5 mm, for example. 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.

Next, the outer peripheral surface of the work 1 is cut by the end mill 20 . Cutting is 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 structure, the rigidity of a blade is ensured, and a pocket is ensured and a cutting chip can be discharged|emitted favorably. In one embodiment, an end mill with a torsion angle of 0° is used. In the present invention, even if an end mill having a torsion angle of 0° which tends to easily form an unnecessary concave portion at the time of contact with a work piece is used, the generation of the concave portion can be prevented.

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 - 6 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 of the end mill is preferably 500 mm/min to 10000 mm/min, more preferably 500 mm/min to 2500 mm/min. Also, in this specification, the speed of the end mill is relative to the work.

In one embodiment, at the start of cutting, the said end mill is made to contact a workpiece|work while traveling an end mill from an oblique direction with respect to a workpiece|work in planar view. In this specification, the 'inclined direction with respect to the workpiece' at the start of cutting refers to the cutting start point (a) (the point at which the end mill first comes into contact with the workpiece), in the back of the running direction of the end mill after the start of cutting. A direction in which the angle (x) (angle (x) in Fig. 4) formed by the side (A) of the workpiece including the starting point (a) or the tangent (B) of the workpiece at the cutting starting point (a) is 60° or less means In addition, the 'direction inclined with respect to the workpiece' means a direction that does not include a direction perpendicular to or close to perpendicular to the workpiece, that is, includes a direction in which the angle (x) is 0°. In addition, in this specification, the said angle (x) is called the traveling angle (x) of the end mill at the time of a cutting start. When the cutting start point (a) is on a straight line, the travel angle (x) of the end mill at the start of cutting is defined from the side (A) of the workpiece including the cutting start point (a) and the travel trajectory of the end mill ( 4), when the cutting start point (a) is on the curve, the travel angle (x) of the end mill at the start of cutting is obtained from the tangent (B) of the workpiece at the cutting start point (a) and the travel trajectory of the end mill defined (FIG. 5).

4(a) and 4(b) are schematic plan views for explaining cutting according to one embodiment of the present invention. 5(a) and 5(b) are schematic plan views for explaining cutting according to another embodiment of the present invention. In Figs. 4(a) and 4(b), and Figs. 5(a) and 5(b), the movement of the end mill (movement relative to the workpiece 1) at the start of cutting is the travel trajectory in plan view. (ts) is shown. 4(a) and (b), the workpiece|work 1 is substantially rectangular shape. In addition, in Fig.5 (a) and (b), the outer edge of the workpiece|work 1 includes a curve. The travel trajectory ts of the end mill at the start of cutting may be curved as shown in Figs. 4(a) and 5(a) or may be linear as shown in Figs. 4(b) and 5(b). may be The traveling angle (x) of the end mill at the start of cutting is 60° or less as described above, preferably 0° or more and 60° or less, more preferably 0° or more and 45° or less, and still more preferably 0° or more. It is 40 degrees or less, Especially preferably, they are 0 degrees or more and 35 degrees or less. In this invention, generation|occurrence|production of the unnecessary recessed part at a cutting starting point can be prevented by making the said end mill contact a work while traveling an end mill from an oblique direction with respect to a work. The traveling angle x of the end mill at the start of cutting is preferably closer to 0°, and in one embodiment, the traveling angle x is 5° or less (preferably 3° or less, more preferably 1° or less) , more preferably 0.5° or less). In addition, the traveling trajectory ts only needs to satisfy the above traveling angle x at the start of cutting, and any trajectory until the start of cutting (for example, before 2 seconds before the end mill contacts the workpiece) The end mill may be driven by

As described above, the traveling angle x may be 0°. For example, when the workpiece is rectangular, the vertex of the workpiece is the cutting start point, and the end mill is driven from a direction parallel to one side of the workpiece. The end mill may be brought into contact with the work while making it, but preferably, the apex of the work is not used as the cutting start point (that is, when the work is rectangular, the travel angle (x) is preferably larger than 0°). When the vertex of the workpiece is used as the cutting start point, there is a possibility that burrs may be generated at the cutting start point.

Preferably, the running trajectory ts of the end mill at the start of cutting is curved. By making the traveling trajectory ts of the end mill at the start of cutting into a curved shape, the effect of the said this invention becomes more remarkable. When the traveling trajectory ts is curved, the traveling angle x of the end mill at the start of cutting is the tangent (us) of the traveling trajectory (ts) at the cutting start point (a), the side of the workpiece (A) or It is defined by the tangent (B) at the starting point of cutting (a). In one embodiment, by bringing the end mill and the work into contact with each other while rotating the work in-plane, the end mill is relatively run with respect to the work on a curved travel trajectory ts. When bringing the end mill and the work closer together, the work may be brought closer to the fixed end mill, the end mill may be moved linearly to bring the end mill and the work closer together, or both the end mill and the work may be moved linearly to bring the end mill and the work closer together. The mill and the work may be brought close together.

When the running trajectory ts of the end mill at the start of cutting is curved, the radius of curvature of the running trajectory ts is preferably 1/2 or more of the outer diameter of the end mill, more preferably larger than the outer diameter of the end mill, It is more preferably 110% or more with respect to the outer diameter of the mill, particularly preferably 130% or more with respect to the outer diameter of the end mill, and most preferably 150% or more with respect to the outer diameter of the end mill. By setting it as such a range, generation|occurrence|production of the unnecessary recessed part at the cutting start point a can be prevented. Further, when the running trajectory ts of the end mill at the start of cutting is curved, the radius of curvature of the running trajectory ts is preferably 4 mm or more, more preferably 6 mm or more, still more preferably 7.5 mm or more. am.

It is preferable that the speed of the end mill when the end mill is brought into contact with the work is slower than the feed rate of the end mill at the time of cutting (when the surface to be cut of the work is cut with the end mill). By slowing the speed of the end mill at the start of cutting, the rattling of the workpiece can be suppressed. In one embodiment, the speed of the end mill at the time of bringing the end mill into contact with the work is preferably 400 mm/min to 1200 mm/min, more preferably 500 mm/min to 900 mm/min. In one embodiment, for example, when cutting the inner peripheral surface of the hole with respect to a work having a hole, the speed of the end mill when the end mill is brought into contact with the work is preferably 30 mm/min to 1200 mm/min, More preferably, they are 50 mm/min - 1000 mm/min.

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 said workpiece|work may not be a pure rectangular shape, polygonal shape, a circular shape, an elliptical shape, etc., and the shape in which the irregular part was added to these shapes may be sufficient as it. 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.

The cutting method (specifically, the travel trajectory of the end mill at the start of cutting, and the travel trajectory of the end mill at the end of cutting, which will be described later), is as shown in FIG. 6 , a workpiece including the hole 11 . Regarding (1'), it can be applied also when cutting the inner peripheral surface of the hole 11.

In one embodiment, at the end of cutting, the said end mill is spaced apart from a workpiece|work while running the end mill in the oblique direction with respect to a workpiece|work in a planar view. In the present specification, the term "inclined direction with respect to the workpiece" at the end of cutting refers to the cutting end point (b) (the point that separates the end mill from the work) in front of the travel direction of the end mill before the end of cutting, the cutting end point (b) ) means a direction in which the angle (y) (angle (y) in FIG. 7 ) formed by the side (A) of the workpiece or the tangent (B') of the workpiece at the cutting end point (b) is 60° or less. As described above, the 'inclined direction with respect to the work' means a direction that does not include a direction perpendicular to or close to perpendicular to the work, that is, it includes a direction in which the angle y is 0°. In addition, in this specification, the said angle y is called the traveling angle y of the end mill at the time of cutting end. When the cutting end point (b) is on a straight line, the travel angle (y) of the end mill at the end of cutting is defined from the side (A) of the workpiece including the cutting end point (b) and the travel trajectory of the end mill (FIG. 7) , when the cutting end point b is on the curve, the travel angle y of the end mill at the end of cutting is defined from the tangent B' of the workpiece at the cutting end point b and the travel trajectory of the end mill (Fig. 8).

7(a) and 7(b) are schematic plan views for explaining the cutting process according to one embodiment of the present invention. 8(a) and 8(b) are schematic plan views for explaining cutting according to another embodiment of the present invention. 7(a) and 7(b), and FIGS. 8(a) and 8(b), the movement of the end mill (movement relative to the workpiece 1) at the end of cutting is shown as the travel trajectory ( te) is shown. 7(a) and (b), the workpiece|work 1 is substantially rectangular shape. In addition, in FIGS. 8 (a) and (b), the outer edge of the work 1 includes a curve. The travel trajectory te of the end mill at the end of cutting may be curved as shown in Figs. 7(a) and 8(a), or may be linear as shown in Figs. do. The traveling angle y of the end mill at the end of cutting is 60° or less as described above, preferably 0° or more and 60° or less, more preferably 0° or more and 45° or less, and still more preferably 0° or more. It is 40 degrees or less, Especially preferably, they are 0 degrees or more and 35 degrees or less. In the present invention, by separating the end mill from the work while traveling the end mill in an oblique direction relative to the work, it is possible to prevent an unnecessary step difference at the cutting end point and the occurrence of burrs. The traveling angle y of the end mill at the end of cutting is preferably closer to 0°, and in one embodiment, the traveling angle y is 5° or less (preferably 3° or less, more preferably 1° or less) , more preferably 0.5° or less). Further, the travel trajectory te may satisfy the travel angle y at the end of cutting, and after the end mill is separated from the work by a predetermined distance, the end mill may be driven by any trajectory.

As described above, the traveling angle y may be 0°. For example, when the workpiece is rectangular, the vertex of the workpiece is the cutting end point, and the end mill is separated from the workpiece in a direction parallel to one side of the workpiece. do. In one embodiment, when a workpiece|work is rectangular shape, the vertex of a workpiece|work is not made into a cutting end point (that is, when a workpiece|work is rectangular shape, the traveling angle y is set larger than 0 degree).

Preferably, the running trajectory te of the end mill at the end of cutting is curved. By making the travel trajectory te of the end mill at the end of cutting into a curved shape, the above effect becomes more remarkable. When the traveling trajectory te is curved, the traveling angle y of the end mill at the end of the cutting is the tangent ue of the traveling trajectory te at the cutting end point b, and the side A of the workpiece or the cutting It is defined by the tangent (B') at the endpoint (a). In one embodiment, by separating the end mill from the work while rotating the work in-plane, the end mill is relatively run with respect to the work on a curved travel trajectory te. When separating the end mill and the work, the work may be separated from the fixed end mill, the end mill may be moved linearly to separate the end mill from the work, or both the end mill and the work may be moved linearly to separate the end mill from the end mill. You may separate the work.

When the running trajectory te of the end mill at the end of cutting is curved, the radius of curvature of the running trajectory te is preferably 1/2 or more of the outer diameter of the end mill, more preferably larger than the outer diameter of the end mill, It is more preferably 110% or more with respect to the outer diameter, particularly preferably 130% or more with respect to the outer diameter of the end mill, and most preferably 150% or more with respect to the outer diameter of the end mill. By setting it as such a range, generation|occurrence|production of unnecessary level|step difference and a burr at the cutting end point (b) can be prevented. Further, when the running trajectory te of the end mill at the end of cutting is curved, the radius of curvature of the running trajectory te is preferably 4 mm or more, more preferably 6 mm or more, and still more preferably 7.5 mm or more. am.

It is preferable that the speed of the end mill when separating the end mill from the work is slower than the feed rate of the end mill at the time of cutting (when the surface to be cut of the work is cut with the end mill). By slowing down the speed of the end mill at the end of cutting, rattling of the workpiece can be suppressed. In one embodiment, the speed of this end mill at the time of separating an end mill from a workpiece|work becomes like this. Preferably they are 400 mm/min - 1200 mm/min, More preferably, they are 500 mm/min - 900 mm/min. In one embodiment, for example, in the case of cutting the inner peripheral surface of the hole with respect to a work having a hole, the speed of the end mill when the end mill is separated from the work is preferably 30 mm/min to 1200 mm/min, and more Preferably they are 50 mm/min - 1000 mm/min.

When cutting is performed over the entire circumference of the outer peripheral surface of the workpiece or the inner peripheral surface of the hole, the cutting start point (a) and the cutting end point (b) may be at the same position, and the cutting start point (a) and the cutting end point (b) may be different positions, and the cutting end point b may be set forward in the running direction of the end mill rather than the cutting start point a. Preferably, the cutting start point (a) and the cutting end point (b) are set to different positions, and the cutting end point (b) is set ahead of the cutting start point (a) in the traveling direction of the end mill. In this way, when the cutting is terminated with the running trajectories of the end mill partially overlapping during the cutting process, unnecessary steps and burrs can be preferably prevented from occurring at the end of the cutting. As described above, when the cutting end point (b) is set ahead of the cutting start point (a) in the traveling direction of the end mill, the distance between the cutting start point (a) and the cutting end point (b) is preferably 0.1 mm to 5 mm and more preferably 0.3 mm to 4 mm, and still more preferably 0.5 mm to 2 mm.

In one embodiment, the end mill is driven as described above at the start of cutting, and the end mill is driven as described above at the end of cutting. In another embodiment, the end mill is driven as described above at the start of cutting, and at the end of cutting, the end mill is driven by an arbitrary method. In another embodiment, the end mill is driven by an arbitrary method at the start of cutting, and the end mill is driven as described above at the end of cutting.

In one embodiment, the optical film comprises 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 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. 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.

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 has a rectangular shape including a side parallel to the absorption axis of the polarizer, the length of the side parallel to the absorption axis of the polarizer is 10 mm to 400 mm, and the length of the other side is 10 mm to 500 mm am. 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°.

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 instrument panel or smart watch of a vehicle. .

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). A plurality of punched optical films were overlapped to obtain a work (total thickness of about 10 mm). The entire periphery of the outer peripheral surface of the work was cut with an end mill while the obtained work was clamped with a clamp (jig). At the start of cutting, while running the end mill from an oblique direction with respect to the workpiece in a planar view (trajectory of the end mill at the start of cutting (ts): on a curve with a radius of curvature of 7.5 mm, the travel angle of the end mill at the start of cutting ( x): 13°, end mill speed at the start of cutting: 700 mm/min), and the end mill was brought into contact with the work. In addition, the outer diameter of the end mill was 5 mm, the number of blades was 2 sheets, and the twist angle was 0 degree. 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.

By the above cutting process, it was possible to obtain a cut optical film without generating an unnecessary concave portion at the cutting starting point.

[Example 2]

In the same manner as in Example 1, cutting was started, and at the end of cutting, the end mill was moved away from the work while the end mill was traveling in an oblique direction with respect to the work in a planar view (trajectory of the end mill at the end of cutting (te)) : On a curved line with a radius of curvature of 7.5 mm, the travel angle of the end mill at the end of cutting (y): 0°, the speed of the end mill at the end of the cut: 700 mm/min). In addition, the cutting end point (b) was made into the traveling direction forward of the end mill from the cutting start point (a), and the distance between the cutting start point (a) and the cutting end point (b) was 1 mm.

By the above cutting process, it was possible to obtain a cut optical film without the occurrence of an unnecessary concave portion at the cutting start point and without the occurrence of a step difference or burr at the cutting end point.

[Example 3]

At the start of cutting, with the apex of the work as the cutting start point, while the end mill is running in a direction parallel to the long side of the work (trajectory of the end mill at the start of cutting (ts): in a straight line, the end mill travels at the start of cutting) Angle (x): 0°, end mill speed at the start of cutting: 700 mm/min), and except that the end mill was brought into contact with the work, cutting was performed in the same manner as in Example 1.

By the above cutting process, a cut optical film was obtained without generation of unnecessary concavities at the cutting starting point, but generation of burrs was found at the cutting starting point.

[Example 4]

By a commercial method, in order from the visual recognition side, surface protection film (48 µm)/hard coat layer (5 µm)/cycloolefin-based protective film (47 µm)/polarizer (5 µm)/cycloolefin-based protective film (24 µm) The optical film (polarizing plate) which has the structure of / 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). A plurality of punched optical films were overlapped to obtain a work (total thickness of about 10 mm). The entire circumference of the outer peripheral surface of the work was cut with an end mill while the obtained work was clamped with a clamp (jig). At the end of cutting, the end mill was separated from the work while running the end mill in an oblique direction relative to the work in plan view (trajectory of the end mill at the end of cutting (te): curved shape with a radius of curvature of 7.5 mm, cutting Travel angle of end mill at end (y): 30°, end mill speed at end of cut: 700 mm/min). In addition, the outer diameter of the end mill was 5 mm, the number of blades was 2 sheets, and the twist angle was 0 degree. 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.

By the above cutting process, it was possible to obtain a cut optical film without the occurrence of a step difference or a burr at the cutting end point.

[Comparative Example 1]

At the start of cutting, cutting was performed in the same manner as in Example 1, except that the end mill was brought into contact with the work while the end mill was traveling in a direction perpendicular to the work in plan view.

According to the above cutting process, unnecessary recesses at the cutting start point were found.

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 (12)

stacking a plurality of optical films to form a work; and
cutting the workpiece with an end mill,
At the start of cutting, bringing the end mill into contact with the work while driving the end mill from an oblique direction with respect to the work in plan view, and/or at the end of cutting, in a direction oblique with respect to the work in plan view. Comprising separating the end mill from the work while driving the end mill,
A method for manufacturing a cut optical film. According to claim 1,
A method for producing a cut optical film, wherein the travel trajectory (ts) of the end mill at the start of cutting is curved. 3. The method of claim 2,
The method of manufacturing a cut optical film, wherein the radius of curvature of the running trajectory (ts) of the end mill at the start of the cutting is greater than 1/2 of the outer diameter of the end mill. 3. The method of claim 2,
The method for manufacturing a cut optical film, wherein the radius of curvature of the running trajectory (ts) of the end mill at the start of the cutting is larger than the outer diameter of the end mill. 5. The method according to any one of claims 1 to 4,
A method for producing a cut optical film, wherein the travel trajectory te of the end mill at the end of cutting is curved. 6. The method of claim 5,
The method of claim 1, wherein the radius of curvature of the travel trajectory te of the end mill at the end of the cutting is greater than 1/2 of the outer diameter of the end mill. 6. The method of claim 5,
The method for manufacturing a cut optical film, wherein the radius of curvature of the travel trajectory (te) of the end mill at the end of the cutting is larger than the outer diameter of the end mill. 8. The method according to any one of claims 1 to 7,
A method for producing a cut optical film, wherein a speed of the end mill when the end mill is brought into contact with the work is slower than a feed rate of the end mill when the outer peripheral surface of the work is cut with the end mill. 9. The method according to any one of claims 1 to 8,
The method for manufacturing a cut optical film, wherein the speed of the end mill when separating the end mill from the work is slower than the feed rate of the end mill when cutting the outer peripheral surface of the work with the end mill. 10. The method according to any one of claims 1 to 9,
Cutting is performed over the entire perimeter of the outer peripheral surface of the workpiece, and the cutting start point (a) and the cutting end point (b) are set to different positions, and the cutting end point (b) ahead of the cutting start point (a) in the running direction of the end mill The manufacturing method of the optical film by which this was set. 11. The method according to any one of claims 1 to 10,
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 1 to 11,
The twist angle of the end mill is 0 °, the manufacturing method of the cut-processed optical film.

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