JP2003146495A - Winding core for film and winding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core and a winding method, not causing an appearance defect possibly generated in a core part when winding a film in a roll state by use of the core. SOLUTION: In this core winding the film, surface hardness of all the peripheral surface or a part of the peripheral surface winding the film is 1-50 degree in the SRIS 0101 scale. By the winding method for winding the film by use of the core, the appearance defect in the core part can be prevented regardless of a thickness change of the film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film winding core, a winding method, and a film to be wound into a roll, and protects the film from a step at the start of film winding that causes poor transparency and deformation. The present invention relates to a film winding method and a core used therefor that prevent the appearance of the film from being impaired, and a film roll obtained by the film winding method.

[0002]

2. Description of the Related Art When a film is continuously manufactured, an ordinary long film uses a tubular or cylindrical core.
It is wound into a roll along the outer circumference of the core. Commonly used cores are those made of hard plastic such as vinyl chloride pipes, those made by compressing paper into tubular or cylindrical shapes, those made of metal such as iron, aluminum, stainless steel, etc., It is required to have a certain strength or more so that the wound long film is not deformed or cracked due to its weight.

However, since the core of the above-mentioned material generally has a hard surface, when the film is wound into a roll, in the core portion, between the winding end of the innermost layer and the core, or the adhesive tape. When using, a step is created between the adhesive tape and the core, and as a result of the film being wound on this step, the film is deformed, and horizontal streaks and transverse stripes are formed in the width direction of the film from the start of winding to several tens of circumferences There was a problem of scratches and distortion. The thicker the film or adhesive tape is, the larger the step difference at the winding end is, so that the effect of this phenomenon is also large. In particular, in the optical film where the appearance and transparency of the film are important, the transverse loss, scratches, distortion, etc. in the winding core cause the transparency to be lost, the flatness to be impaired, and wrinkles to occur. cause. The defective appearance is tens of meters from the core
To several hundred meters, which is a cause of a decrease in product yield.

As an attempt to improve the appearance defect of such a film, for example, Japanese Patent Laid-Open No. 9-315637 has been proposed. However, this method of cutting the film end face and judging the end face angle with a microscope is a skill It takes work,
It was a dangerous method when cutting and was not suitable for actual production. In addition, it is difficult to actually determine the angle with a microscope online, and it cannot be applied to continuous production. Further, in Japanese Patent Laid-Open No. 11-157592, there is proposed a method in which a step corresponding to the film thickness is provided on the core and the steps of the winding core are eliminated by abutting the ends of the film. In addition, it is difficult to precisely process the core so as to have a step, and it is necessary to change the step of the core when the thickness of the film is changed, so that the versatility is poor.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve a flatness / transparency defect due to a thickness difference at a winding end of a film and to obtain a film in a high yield. And to provide a film roll using the core.

[0006]

The present inventors have arrived at the present invention as a result of intensive studies to solve such problems. That is, the gist of the film winding core in the present invention is that the surface hardness of a part or the whole of the outer peripheral surface on which the film is wound is 1 degree or more and 50 degrees or less on the SRIS0101 scale.

In one embodiment, the core comprises at least an elastic body and a core material, and has a thickness of 0.1 mm.
The surface hardness of a part or the whole of the outer peripheral surface on which the film is wound is SRI
It is adjusted within the range of 1 degree or more and 50 degrees or less on the S 0101 scale.

Further, the gist of the film winding method in the present invention is to use a core in which the surface hardness of a part or the whole of the outer peripheral surface on which the film is wound is 1 degree or more and 50 degrees or less on the SRIS 0101 scale. It is characterized by being used and wound up.

Further, the film winding method is characterized in that the poor transparency and deformation due to the step at the film winding start portion are eliminated from the start of winding to the length of 20 circumferences. An optical film roll is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a film winding core and a winding method using the same according to the present invention will be described in detail below.

The core used to wind up the film roll of the present invention is typically cylindrical or tubular, and the surface hardness of a part or the entire outer peripheral surface of the film is 1 on the SRIS 0101 scale. The feature is that the angle is not less than 50 degrees and not more than 50 degrees.

In the core of the present invention, when the entire surface of the outer peripheral surface on which the film is wound has the above-mentioned surface hardness, the winding start of the film may be performed anywhere.

However, in a core having a part within the above range of surface hardness, that part must be the winding start position. Further, in that case, it is preferable to set the surface hardness within the above range across the width direction of the core, and if the length (width) in the circumferential direction is too small, it becomes difficult to align the winding start. It is preferably 15 mm or more.

The surface hardness is 1 since the deformation of the surface elastic layer becomes remarkable due to the tension generated when the film is wound, and the long film may not be able to be wound up.
The degree is preferably 3 degrees or more, more preferably 3 degrees or more.
Further, in order to eliminate the step difference at the beginning of winding, the surface hardness is 5
It is preferably 0 degrees or less, and more preferably 20 degrees or less.

In order to make the surface hardness of the core 1 degree or more and 50 degrees or less on the SRIS 0101 scale, a method using an elastic body can be mentioned. However, on the other hand, in order to achieve the core's original purpose of winding a long film,
It must have enough strength to withstand the tension during winding and the weight of the film. Therefore, when the core is made of the elastic body alone, the load bearing capacity thereof becomes a problem. Therefore, the core of the present invention preferably has a structure including at least an elastic body and a core material, and the surface hardness of a part or the whole of the outer peripheral surface on which the film is wound by the elastic body is 1 on the SRIS 0101 scale.
It is preferable to adjust within the range of not less than 50 degrees and not more than 50 degrees.

The core material of the core is paper, resin-impregnated paper,
It is preferably made of plastic, glass epoxy or metal, but is not limited thereto. The elastic body may be wrapped around the entire circumference of these core materials, or may be attached to a part of them, or may be provided with a cutout portion to be embedded. When sticking, a step corresponding to the thickness of the elastic body is formed, and this step may adversely affect. Therefore, the cross section of the elastic body is preferably trapezoidal.

The material of the elastic body used for adjusting the surface hardness of the core is not particularly limited, but foam such as sponge, elastic body such as rubber, cloth such as felt can be preferably used. Further, if the thickness of the elastic body is too thin, the surface hardness of the core cannot be reduced to a desired range. Therefore, the thickness is preferably 0.1 mm or more, more preferably 3 mm or more. Also, if the thickness is too large, the deformation of the elastic body may become too large,
The thickness is preferably 30 mm or less, more preferably 20 mm or less. The thickness of the elastic body referred to here means the length of the elastic body from the center of the core toward the outer peripheral surface direction.

The method of forming the elastic body portion is not particularly limited, and as described above, a method of winding a rubber or sponge sheet around the outer peripheral surface of the core material, or applying an elastic solution or the like to the outer peripheral surface of the core material and solidifying it. There is a method to make it possible, but if you create a seamless tubular elastic body in advance and insert a nucleus such as a PVC pipe inside it and fix it, a step due to the seam will occur on the outer peripheral surface Of course, this is the most preferable method.

Further, the above-mentioned elastic body is preferably used on the outermost periphery of the core, but if problems such as surface contamination occur when it is brought into direct contact with the film to be wound, a protective layer may be provided on the outermost periphery. . Whichever method is used, the elastic body and the protective layer are preferably fixed to the core. If the elastic body or protective layer is not fixed, winding misalignment or winding tightness may occur, which causes new scratches or horizontal streaks,
It may cause a plane defect.

Next, the material of the film wound around the core is not particularly limited, and the present invention can be applied to any film-shaped material represented by a plastic film. Examples of plastic films include polyolefin resins represented by polyethylene and polypropylene, polystyrene resins, vinyl chloride resins, polyester resins represented by polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polynorbornene resins. , Polyamide resin,
Polyimide resin, polyester resin, polyetherimide resin, acrylic resin, polyketone resin, polyphenylene oxide resin, polyphenylene sulfide resin, polysulfone resin, polycarbonate resin, polyarylate resin, polyphenylene sulfide resin, Phenolic resins, urea resins, melamine resins, fluorine resins and the like can be mentioned. These may be used alone or in combination. Alternatively, a copolymer represented by AS resin or ABS resin can be used. Further, the film using these may contain internally precipitated particles generated during polymerization, and inert inorganic particles or organic particles represented by calcium carbonate, aluminum oxide, silicon oxide, titanium oxide and the like. Also,
Besides the plastic film, it can be applied to a sheet made of paper or cloth.

The film roll obtained in the present invention can be used in all kinds of applications, and particularly suitable one is an optical film which requires a high level of flatness and visibility is important. The resin used for the optical film is a material having high transparency among the above-mentioned materials and is not particularly limited, but examples thereof include a polyolefin resin, an acrylic resin, a polynorbornene resin, Examples thereof include polycarbonate resin, polyarylate resin, and cellulose resin. As the optical film, a retardation film, a color filter,
Examples thereof include a polarizing film and an adhesive sheet.

The winding method of the present invention for winding these films around the core of the present invention is not particularly limited, except that the core is used as the core. That is, the same winding conditions as those when using a general core can be applied.

Now, the effect of the winding core of the present invention will be described.

FIG. 1 is a general view of a film roll wound on a core. Further, FIG. 2 is an enlarged view of a portion A of FIG. 1 when a conventional general core is used, and FIG. 3 is an enlarged view of FIG. A when a core of the present invention is used. As shown in FIG. 2, when the conventional core is used, it is unavoidable that a step (3a) having a height corresponding to the thickness of the film is generated at the beginning of winding, and it is wound after the second winding. The film is affected by the step, and damages such as horizontal stripes, scratches, and distortion occur in the width direction of the film. However, when the core of the present invention having the surface elastic layer (2) in the outer peripheral portion as shown in FIG. 3 is used, the winding start portion of the film is embedded in the surface elastic layer due to the pressure generated when winding the film. ,
The winding start portion of the film and the surface elastic layer form a continuous flat surface. Therefore, the second film can be wound without being affected by the step.

[0025]

EXAMPLES The contents of the present invention will be specifically described below based on examples, but the present invention is not limited thereto.

Regarding the measurement of the hardness of the outer peripheral surface in the present invention, SRIS 0101 (Japan Rubber Association standard)
It was measured according to. In the present invention, an Asker C type hardness tester (manufactured by Kobunshi Keiki Co., Ltd.) was used as the measuring machine.

Further, the poor transparency and deformation of the film, and the confirmation of the horizontal stripes were carried out by visual inspection.

In the present invention, the thickness of the film, the adhesive tape, etc. is the stylus type thickness gauge KG60 manufactured by Anritsu Corporation.
1A was used.

The thickness of the surface elastic layer and the core were measured with a caliper.

(Example 1) As the core material of the core, an inner diameter of 15
A PVC pipe having a width of 2 mm, a width of 1250 mm and a thickness of 7 mm was used. An NBS-based rubber sheet having a thickness of 1.5 mm was attached to the entire outer periphery with an adhesive, and the surface hardness of the core was adjusted to 30 degrees (SRIS 0101 scale).
A film made of polycarbonate (width: 1000 mm, thickness: 70 μm) is applied to the outer periphery at a tension of 147 N / m for 1000 m.
I wound up. The winding start end has a width of 10 mm and a thickness of 100 μ.
A double-sided adhesive tape of m was attached and fixed in the width direction with a length of 1000 mm. After winding, the film was rewound and the appearance of the film up to 30 m from the winding core was visually observed. As a result, horizontal streaks and deformation due to steps disappeared from the first winding onward from the first lap, and the loss was 0.5 m.

(Example 2) As the core material of the core, an inner diameter of 15
A PVC pipe having a width of 2 mm, a width of 1250 mm and a thickness of 7 mm was used. A sheet of silicon sponge having a thickness of 1.5 mm was attached to the entire outer periphery with an adhesive, and the surface hardness of the core was adjusted to 8 degrees (SRIS 0101 scale). A polycarbonate film (width 1000 mm, thickness 70 μm) of 100 is applied to the outer periphery with a tension of 118 N / m.
It was wound up 0m. The winding start end has a width of 10 mm and a thickness of 10
A 0 μm double-sided adhesive tape was attached and fixed in the width direction with a length of 1000 mm. After winding, the film was rewound and the appearance of the film was visually observed from the core to the end of the winding. No horizontal streaks or deformations due to steps were found.

Example 3 As the core material of the core, an inner diameter of 15
A PVC pipe having a width of 2 mm, a width of 1250 mm and a thickness of 7 mm was used. A silicon sponge sheet of the same material as that used in Example 2 having a trapezoidal cross section with a width of about 3 cm, a length of 1200 mm, and a thickness of 1.5 mm was attached to the outer periphery thereof with an adhesive, and Surface hardness 8 degrees (SRIS 01
01 scale). Using the core, tension 14
The same film as in Example 1 was wound at 1000 N at 7 N / m. The winding start end has a width of 10 mm and a thickness of 100 μm.
After wrapping the double-sided pressure-sensitive adhesive tape of 1000 mm in the width direction and fixing it, after winding and visually observing the appearance of the film up to 300 m from the core, horizontal streaks and deformations due to steps are 3 turns from the core. It disappears by the eye and the loss is 1.5m
Met.

Example 4 Using the core used in Example 1, a polyester (polyethylene terephthalate) film (thickness 125 μm) was used as a film, and the film was wound up at a tension of 137 N / m for 1000 m. After winding, the appearance of the film from the core up to 30 m was visually inspected, and no horizontal streaks or deformations due to steps were found on the core.

(Comparative Example 1) As the core material of the core, an inner diameter of 15
2mm, width 1500mm, thickness 7mm PVC pipe,
The outer peripheral surface was not processed, the winding end was directly attached to the outer peripheral surface of the PVC pipe, and the polycarbonate film used in Example 1 was wound up at a tension of 147 N / m for 1000 m.
When the roll after winding was rewound and the appearance of the film was visually observed, horizontal streaks and deformation due to steps were observed from the winding core to a portion of 75 m, and it could not be used as an optical film.

(Comparative Example 2) As the core material of the core, an inner diameter of 15
2mm, width 1500mm, thickness 7mm PVC pipe,
The outer peripheral surface was not processed, the winding end was directly attached to the outer peripheral surface of the PVC pipe, and the polyester film used in Example 3 was wound up at a tension of 147 N / m for 1000 m. When the roll after winding was rewound and the appearance of the film was visually observed, horizontal streaks and deformation due to steps were observed from the winding core to the portion 100 m away.

(Comparative Example 3) As the core material of the core, an inner diameter of 15
A PVC pipe having a width of 2 mm, a width of 1250 mm and a thickness of 7 mm was used. A fluororubber sheet having a thickness of 1.5 mm was attached to the entire outer periphery with an adhesive, and the surface hardness of the core was adjusted to 70 degrees (SRIS 0101 scale). Using the core, a film similar to that in Example 1 was wound up for 1000 m with a tension of 147 N / m. After winding, horizontal streaks and deformation due to steps were observed from the winding core to a portion of about 40 laps (about 21 m).

[0037]

As described above, according to the winding core of the present invention, when the film is wound into a roll, a step generated at the winding core portion and deformation of the film due to the step are prevented, and It is possible to obtain effects such as improvement in yield and quality.

Specifically, in the film roll wound by the winding method of the present invention, the poor transparency and the deformation due to the step at the film winding start portion are eliminated from the start of winding to the length of 20 laps. Therefore, it is possible to suppress a decrease in yield.

[Brief description of drawings]

FIG. 1 is a diagram of a typical film roll using a core.

FIG. 2 is an enlarged cross-sectional view of a portion A in FIG. 1 of a film roll using a conventional general core.

FIG. 3 is an enlarged view of part A in FIG. 1 of a film roll having a core wound with a film according to the present invention.

[Explanation of symbols]

1 core 2 Surface elastic fixed to the outer periphery of the core 3 film 3a Film winding start end

Claims (4)

[Claims] 1. A core for winding a film, wherein the surface hardness of a part or the entire outer peripheral surface of the film is 1 to 50 degrees on the SRIS 0101 scale. 2. A core comprising at least an elastic body and a core material, wherein the elastic body has a thickness of 0.1 mm or more and 20 mm or less, and the elastic body winds a part or the entire outer peripheral surface of the film. Hardness is SRIS 010
The core according to claim 1, wherein the core is adjusted within a range of 1 degree or more and 50 degrees or less on one scale. 3. A film winding method for winding a film on a core, wherein a core having a surface hardness of a part or the entire outer peripheral surface of the film is 1 degree or more and 50 degrees or less on an SRIS 0101 scale. A method for winding a film, characterized in that the film is wound up. 4. The winding method according to claim 3, wherein the poor transparency and the deformation due to the stepped portion at the film winding start portion are eliminated from the winding start to the length of 20 circumferences. Taken optical film roll.