CN216187633U

CN216187633U - Roll of optical film

Info

Publication number: CN216187633U
Application number: CN202122506990.4U
Authority: CN
Inventors: 堀口司; 藤井干士; 西幸二朗
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2020-10-21
Filing date: 2021-10-18
Publication date: 2022-04-05
Anticipated expiration: 2031-10-18
Also published as: JP3230067U

Abstract

The utility model provides a reel capable of reducing defects such as winding deviation in a reel of an optical film with a mark. A roll (100A) of the present invention is a roll of an optical film (100) wound around a core, wherein 3 or more marks (70) are provided to the optical film (100) in the winding direction, and the distances (D) between the marks (70) are different from the distances (D') between adjacent marks.

Description

Roll of optical film

Technical Field

The present invention relates to a roll of optical film.

Background

As a material of the optical film, a roll of the optical film wound around a core is known.

In such a roll of optical film, in order to provide a reference for a position in a winding direction, a large number of marks are sometimes given to the optical film at regular intervals in the winding direction by a laser beam or the like.

Documents of the prior art

Patent document

Patent document 1: japanese Kohyo publication No. 2019-512393

Patent document 2: japanese patent No. 5347406

Patent document 3: japanese patent No. 5925609

SUMMERY OF THE UTILITY MODEL

Problem to be solved by the utility model

However, it has been found that, in such a roll of optical film provided with a mark, a winding deviation (japanese: reel ずれ) or the like is liable to occur.

The present invention has been made in view of the above problems, and an object thereof is to provide a roll of an optical film to which a mark is applied, which can reduce defects such as winding displacement in the roll.

Means for solving the problems

The roll of the present invention is a roll of an optical film wound around a core, wherein 3 or more marks are provided to the optical film in a winding direction, and distances between the marks are different from adjacent ones of the distances.

Here, the distance may be different from the adjacent distance by 1mm or more, respectively.

In addition, when the maximum diameter of the reel of the portion to which the mark is applied in the axial direction of the reel is RM and the minimum diameter of the reel is RC, the following equation may be satisfied.

1≤RM/RC≤1.05

The length of the optical film in the winding direction may be 100m or more, and the number of the marks may be 100 or more.

Effect of the utility model

According to the present invention, it is possible to provide a roll in which defects such as winding displacement in a roll of an optical film to which a mark is applied can be reduced.

Drawings

Fig. 1 is a cross-sectional view perpendicular to a winding axis of a roll of the optical film of the present invention.

Fig. 2 is a perspective view showing a state in which a part of the optical film is pulled out from the roll of fig. 1.

Fig. 3 is a top view of a roll of the optical film of fig. 1.

Description of the reference numerals

100A roll, 100 optical film, 10 cores, 70 mark.

Detailed Description

A roll of optical film according to an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a schematic diagram showing a cross section of a roll of optical film according to an embodiment of the present invention. The roll 100A of the optical film 100 is wound around the circumferential surface of the core 10.

The core 10 has a cylindrical or barrel shape. The material of the core 10 is not particularly limited, and may be, for example, resin, paper, or the like. The diameter of the core 10 may be, for example, 50mm to 400 mm.

The axial length of the core 10 may be 500mm to 2000 mm. As shown in fig. 2 and 3, the axial length of the core 10 is generally greater than the width of the optical film 100, and both ends of the core 10 in the axial direction protrude from the optical film 100.

As shown in fig. 2, the optical film 100 has a strip shape and is wound around the core 10.

The length of the optical film 100 in the longitudinal direction (winding direction) is not limited, and may be, for example, 100m or more.

The width (length in the axial direction of the core) of the optical film 100 is also not particularly limited, and may be, for example, 500mm to 2000 mm.

The thickness of the optical film 100 is not particularly limited, and may be, for example, 20 to 500 μm, preferably 50 to 500 μm, and more preferably 50 to 200 μm.

The optical film 100 may be a single-layer film or a laminated film.

An example of a single layer film is a resin film. Examples of the resin include a cellulose-based resin (triacetyl cellulose and the like), a polyolefin-based resin (polypropylene-based resin and the like), a cycloolefin-based resin (norbornene-based resin and the like), an acrylic-based resin (polymethyl methacrylate-based resin and the like), a polyester-based resin (polyethylene terephthalate-based resin and the like), and a polyimide-based resin (polyimide, polyamideimide) and the like. These single-layer films may be protective films, substrate films, retardation films, window films, and the like.

The laminated film is an optical film having a plurality of layers. Examples of the laminated film are a polarizing film, a circularly polarizing plate, and a touch sensor.

For example, a polarizing film includes at least a protective layer (substrate layer) and a polarizing plate.

The circularly polarizing plate has, for example, a polarizer and a phase difference (1/4 λ) layer.

The touch sensor may include a transparent substrate layer, a sensing pattern layer, and a sensing line.

The laminated film may further include an adhesive layer and an adhesive layer.

The adhesive is a material having adhesiveness and capable of being directly bonded to another member at room temperature. Examples of the adhesive are an acrylic adhesive, a silicone adhesive, and a urethane adhesive. The pressure-sensitive adhesive may be a pressure-sensitive adhesive layer which has adhesiveness before curing, can be bonded to another member at room temperature, and has improved adhesive strength when crosslinked by a method such as heat or light in a subsequent step and cured. An example of such an adhesive is an acrylic adhesive binder.

The adhesive is a material that fixes 2 layers after curing by reaction. Examples of the adhesive include an acrylic adhesive and a silicone adhesive.

The optical film may further include a release layer which is bonded to the adhesive layer to protect the adhesive layer and is peeled off when the adhesive layer is bonded to another member; and a protective layer which is attached to a layer constituting the optical film to protect the layer from damage during transportation and the like.

Examples of the release layer and the protective layer are resin films. Examples of the resin include, in addition to the resins exemplified in the resin film, polystyrene, polyethylene terephthalate (japanese patent: ポリエチレンテレフタラート), and the like.

As shown in fig. 1 and 2, the optical film 100 has many marks 70 along the longitudinal direction, i.e., the winding direction. The marks 70 are provided at arbitrary identical positions in the width direction (hereinafter, may be referred to as width direction mark positions) in consideration of reading in a state pulled out from the roll in the subsequent process, as shown in fig. 2. Examples of the widthwise mark position include either one end or both ends in the widthwise direction.

The method of giving the mark 70 is not limited. Examples of the mark 70 include a mark obtained by changing physical properties (light absorption rate, light reflectance, and the like) of the optical film 100 by irradiation with a laser beam, a mark obtained by printing, that is, application of an ink, and a mark obtained by attaching another film with an adhesive such as a seal tape.

The form of the mark 70 is not particularly limited, and may be a two-dimensional code such as a one-dimensional barcode or a QR code (registered trademark), or a form directly having a number or a sign (number or sign itself).

In the present embodiment, each distance D between the marks 70 is different from the distance D between adjacent marks 70. For example, in FIG. 2, distance D₁To adjacent distance D₂Different, distance D₂To adjacent distance D₁And D₃Different, distance D₃To adjacent distance D₂And D₄Different.

The distance D between the marks is usually different from the distance between adjacent marks by 1mm or more, preferably 3mm or more, and more preferably 5mm or more. The difference between the distance D between the marks and the distance between adjacent marks is usually 500mm or less, and preferably 100mm or less.

Further, not only the distance D may be different from the adjacent distance, but also the distance D may be periodically increased or decreased along the winding direction. For example, the distance between the marks is set to D_nWhen n is 1, 2, 3, · · in order along the longitudinal direction, i.e., the winding direction, the following manner may be adopted, namely, according to D₁、D₂、…D_iIncrease in sequential distance of D_i+1Is reduced to a distance of D₁Same value, otherwise, up to D_i+2、D_i+3、…D_2iThe distance to the ground increases in sequence. i.e. iFor example, the amount of the organic solvent is 3 to 30, preferably 3 to 50.

The distance (interval) D between the marks 70 may be, for example, 50mm to 2000mm, preferably 50mm to 1000 mm.

The number of the marks 70 is not particularly limited as long as it is 3 or more, and may be, for example, 100 or more.

The mark 70 is preferably provided in a region close to the widthwise end 100F of the roll 100A, for example, at a distance of 1mm to 50mm from the widthwise end 100F. The distance between each mark 70 and the width direction end 100F may be the same or different from the adjacent mark.

(action)

As a result of research, the inventors of the present invention have found that when the distance D between the marks 70 is constant, the marks 70 are likely to overlap in a specific radial direction at the mark position in the width direction of the roll. The portion of the optical film 100 where the mark 70 exists differs from the other portions in properties such as thickness and elasticity. Therefore, when the marks 70 are overlapped in the specific radial direction at the widthwise mark position of the roll 100A, the outer diameter of the roll in the specific radial direction is greatly increased, which causes winding displacement, film deformation, unevenness formation, tunnels, scratches (scratches), and the like.

For example, as shown in fig. 3, when each mark 70 is provided in the vicinity of the widthwise end 100F of the roll 100A, the outer diameter in the radial direction tends to be larger in the vicinity of the widthwise end 100F, that is, the widthwise end 100E, than in other portions in the widthwise direction of the roll 100A.

However, according to the present embodiment, since the distance D between the marks 70 is not constant, it is possible to suppress the marks 70 from overlapping in a specific radial direction at the mark position in the width direction of the roll. Therefore, a large increase in the outer diameter in the specific radial direction at the widthwise mark position can be suppressed, and troubles such as winding displacement are less likely to occur in the roll.

In the roll of the present embodiment, when the maximum diameter of the roll 100A at the widthwise mark position is RM and the minimum diameter of the roll 100A is RC, the following expression can be satisfied. RM/RC may be 1.02 or less.

1≤RM/RC≤1.05

Such a roll is likely to be a roll in which problems such as winding displacement are reduced.

In the case where a plurality of single films, each having a constant cut feed length, are stacked on each other from a roll in which the distance D between the marks is not constant as described above, the marks are not selectively stacked only at specific positions, and therefore, variation in the thickness of the laminate is suppressed.

Claims

1. A roll of optical film wound around a core, wherein 3 or more marks are provided on the optical film in the winding direction, and the distance between each mark is different from the adjacent distance.

2. The spool as claimed in claim 1,

the distance is different from the adjacent distance by more than 1 mm.

3. The spool according to claim 1 or 2,

when the maximum diameter of the reel of the portion to which the mark is given in the axial direction of the reel is RM and the minimum diameter of the reel is RC, the following equation is satisfied:

1≤RM/RC≤1.05。

4. a spool as claimed in any one of claims 1 to 3,

the length of the optical film in the winding direction is 100m or more, and the number of the marks is 100 or more.