JP2011116525A - Winding core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a winding core capable of eliminating optical or configurational distortion when winding a sheet material around thereof. <P>SOLUTION: A winding core 1 is structured by providing a sheet cutting blade storage groove 3 in a cylindrical winding core body 2 at a position adjacent to a winding starting part 1A on a side opposite to the winding direction, and attaching a step absorbing member 4 to a position adjacent to the blade storage groove 3 on a side opposite to the winding direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a winding core used for winding a sheet-like material such as an adhesive sheet, and more particularly to a winding core that does not leave optical or geometric distortion in the sheet-like material during winding.

  Sheet-like products such as pressure-sensitive adhesive sheets are often wound in a roll shape and shipped because they can be efficiently accumulated in a small space and can be easily transported. Also, in the film-forming process of a sheet-like material such as an adhesive sheet or at the time of slitting, it is carried out in a roll shape, and at this time, a method of winding the sheet-like material around a winding core is adopted. .

Thus, when the sheet-like material is wound around the winding core, the thickness of the winding start end of the sheet and the thickness of the pressure-sensitive adhesive or pressure-sensitive adhesive sheet for fixing the winding start end of the sheet to the winding core are added, In some cases, a step is generated in the winding start portion, and a step mark such as a wrinkle, a step pattern, or a dent is attached to the sheet material. That is, when the first layer is wound from the winding start portion and the second layer is applied, the second layer rides on the winding start portion, and this riding portion becomes a step. This step will eventually be resolved as the layers are wound, but the inner side is maintained in a shape along the step with the winding pressure applied. Strain may remain, resulting in wrinkles, stepped patterns, or dents. In particular, the double-sided pressure-sensitive adhesive sheet is wound more softly than an ordinary film, so that there is a problem that the pressure-sensitive adhesive material is deformed by tightening or the step marks are easily left behind.
Conventionally, methods for solving such problems have been proposed.

For example, Patent Document 1 proposes a method for preventing the occurrence of end surface step marks by providing an elastic layer on the surface of a cylindrical body.
Patent Document 2 proposes a method of eliminating winding marks and winding steps generated in the winding material by providing a recess in the winding core.

JP 2005-162478 A JP 2008-7286 A

  The present invention proposes a winding core having a new configuration that does not leave optical or shape distortion when a sheet-like material such as a double-sided pressure-sensitive adhesive sheet is wound.

  The present invention proposes a winding core having a configuration in which a step-absorbing member is provided on the outer peripheral surface of the winding core on the side opposite to the winding direction of the winding start portion.

  Thus, by attaching a step absorbing member such as a foam to the opposite side to the winding direction of the winding start portion, when the winding material is wound from the winding start portion and applied from the first layer to the second layer, a step is formed. Since the winding material (sheet-like material) can be guided to the winding start portion in a state where the step is absorbed by the absorbing member, the second layer and subsequent layers can be wound without causing a step. Therefore, even if a sheet-like material such as a double-sided pressure-sensitive adhesive sheet is rewound, optical or shape distortion does not remain, so that wrinkles, stepped patterns, dents, etc. can be wound up, Product loss can be suppressed, and a winding body with high economic and environmental value can be provided.

It is sectional drawing which showed an example of one Embodiment of this invention. It is the perspective view which showed an example of one Embodiment of this invention. It is the elements on larger scale which showed an example of the winding start part at the time of winding the winding material of the 2nd layer, in order to explain the function of a level difference absorption member. It is the elements on larger scale which showed an example of a mode that a winding material is cut in order to explain a function of a blade slot.

  Examples of embodiments of the present invention will be described below. However, the scope of the present invention is not limited to the embodiments described below.

  As shown in FIGS. 1 and 2, the winding core 1 according to an example of the embodiment of the present invention is located on the outer periphery of the cylindrical winding core body 2 at a position adjacent to the side opposite to the winding direction of the winding start portion 1A. A blade insertion groove 3 for cutting a sheet is provided, a step absorbing member 4 is provided at a position adjacent to the side opposite to the winding direction of the blade insertion groove 3, and a winding material 11 is wound at a position adjacent to the winding direction of the winding start portion 1A. This is a winding core provided with an adhesive member 5 for fixing the starting end to the winding core body 2. However, it is not always necessary to provide the blade insertion groove 3 and the adhesive member 5 depending on the application.

(Winding core body 2)
The core body 2 may have a single layer structure or a multilayer structure as long as it has a substantially cylindrical shape. In the case of a multilayer structure, the blade groove 3 and the step absorbing member 4 may be provided on the surface of the surface of the core body 2.

  The material of the core body 2 is arbitrary. For example, it may be made of paper, plastic, metal, or a composite system of a plurality of materials. More specifically, ABS resin, vinyl chloride resin, ester resin, polycarbonate, polyamide resin, plastic such as styrene resin, metal such as aluminum, iron, copper, titanium or at least one alloy thereof, FRP Examples thereof include composite materials such as (glass fiber reinforced plastic). In addition, ABS (acrylonitrile butadiene styrene) resin, vinyl chloride, FRP (glass fiber reinforced plastic) resin, polycarbon resin, and the like can be given because they can be reused.

  The outer peripheral surface of the core body 2 may be subjected to a process such as a friction reducing coating process, a dimple process, or an emboss process.

(Blade groove 3)
By providing a cutting groove 3 for film cutting in the axial direction of the winding core body 2 on the outer peripheral surface of the winding core body 2, the cutter blade S is inserted into the cutting groove 3 as shown in FIG. Since the winding material 11 can be cut along the blade insertion groove 3, for example, when the winding material 11 is started to be wound, the edge of the winding material 11 can be cut straight in the axial direction, and the winding start portion The cut surface of 1A does not become curved, and the generation of step marks due to the shape of the cut surface can also be suppressed.

The blade insertion groove 3 is preferably formed from substantially the entire width of the core body 2, that is, from one end portion in the axial direction to the other end portion.
The blade insertion groove 3 is configured so that a cutting means such as a cutter blade can be inserted perpendicularly to the outer peripheral surface of the core body 2, that is, the depth direction of the blade insertion groove 3 is directed toward the center of the cylinder. In other words, it is important to form the core body 2 so as to be deep in the vertical direction with respect to the tangent line on the outer periphery of the core body 2.
However, as for the shape of the blade insertion groove 3, the shape of the groove such as a U-shaped groove, a V-shaped groove, and a slit shape is arbitrary, and the groove width is also arbitrary, for example, 0.3 mm to 3.0 mm, preferably What is necessary is just to form in 0.5 mm-1.0 mm. Moreover, the groove depth is also arbitrary, for example, 0.5 mm to 5.0 mm, preferably 1.0 mm to 2.5 mm.

(Step absorbing member 4)
When the step absorbing member 4 is provided on the side opposite to the winding direction of the winding start portion 1A, as shown in FIG. 3, the winding material 11 is wound from the winding start portion and applied from the first layer to the second layer. When the winding pressure is applied to the winding material 11, the step absorbing member 4 is crushed and absorbs the step, so that the second layer of the winding material 11 can be guided to run on the winding start portion without adding a step.

In this way, the step absorbing member 4 is such that the step absorbing member 4 is crushed and absorbs the step, and the second layer of the winding material 11 is guided on the winding start portion without adding a step, so that it is too soft. However, it is not preferable that it is too hard.
From this point of view, the material of the step absorbing member 4 is, for example, acetyl cellulose, epoxy resin, styrene / polyester resin, phenol resin, polyethylene, polystyrene, silicon, urea formaldehyde resin, polyurethane, synthetic elastomer, polyvinyl chloride, ebonite, and poly Examples thereof include foams such as tetrafluoroethylene, chloroprene rubber, natural rubber, nitrile rubber, urethane rubber, silicone rubber, butyl rubber, fluororubber and other rubber materials, non-woven fabric, felt and the like. Among these, it is preferable to use a foam in terms of compression hardness and ease of molding. Among them, a foamed resin having closed cells and mainly composed of polyolefin such as polyethylene or polypropylene is preferable.

  Further, the hardness of the step absorbing member 4 is such that the 25% compression hardness is 0.001 MPa to 0.100 MPa, particularly 0.001 MPa to 0.050 MPa, especially 0.003 MPa because it is neither too soft nor too hard. The thing of -0.020MPa is preferable.

The thickness of the step absorbing member 4 depends on the thickness and hardness of the wrapping material 11 and also the thickness of the adhesive member 5, but is preferably at least the thickness of the wrapping material 11, particularly the thickness of the wrapping material. More preferably, the thickness is 0 mm to 5.0 mm, more preferably 1.0 mm to 2.0 mm.
Moreover, it is preferable that the width | variety of the level | step difference absorption member 4 is 0.5 cm-5.0 cm, and it is more preferable that it is 1.0 cm-3.0 cm especially.

  Examples of the shape of the step absorbing member 4 include a rectangular parallelepiped, an elliptical columnar body, a triangular columnar body, and other forms having a slope shape whose height increases in the winding direction. It is not limited.

It is important that the position where the step absorbing member 4 is attached is on the side opposite to the winding direction of the winding start portion 1A, may be a position adjacent to the winding start portion 1A, or is appropriately separated from the winding start portion 1A. Alternatively, the groove 3 may be provided between the winding start portion 1A and the step absorbing member 4 as in the present embodiment.
At this time, when the step absorbing member 4 is attached at a position appropriately separated from the winding start portion 1A, it is attached at a position away from the winding start portion 1A by 0.3 mm to 2.0 mm from the viewpoint of securing the space of the groove 3. In particular, it is even more preferable to attach at a position of 0.4 mm to 1.0 mm, particularly 0.5 mm to 0.8 mm apart.

(Adhesive member 5)
It is preferable to attach an adhesive member 5 for fixing the winding start end portion of the winding material 11 to the core body 2 at a position adjacent to the winding direction of the winding start portion 1A.

As the adhesive member 5, an adhesive, a double-sided adhesive tape, etc. can be illustrated.
In any case, the composition of the pressure-sensitive adhesive is arbitrary. For example, a rubber-based, acrylic-based, silicone-based, vinyl ether-based, urethane-based or other viscoelastic polymer, if necessary, rosin-based, petroleum resin-based tackifying resin, Examples thereof include those containing a softener and a crosslinking agent.

  Since the thickness of the adhesive member 5 may cause a step due to its own thickness, a thinner one is preferable. As a guideline, 0.01 mm to 0.10 mm, particularly 0.01 mm to 0.05 mm may be mentioned. it can.

<Winding body>
By winding a sheet-like winding material 11 around the winding core 1, a wound body 10 can be obtained.

  As the winding material 11, a sheet-like material made of various materials such as a resin material, a metal material, paper, a nonwoven fabric, and a cloth can be used. Among these, from the viewpoint of enjoying the effects of the present invention, a resin sheet, particularly a pressure-sensitive adhesive sheet, particularly a pressure-sensitive adhesive sheet having release sheets on both sides can be preferably used.

  When a pressure-sensitive adhesive sheet, particularly a pressure-sensitive adhesive sheet provided with a release sheet on both sides, is used as the wrapping material 11, the thickness is arbitrary, but as a guide, it is 0.10 mm to 0.50 mm, particularly 0.10 mm to 0.30 mm. Can be illustrated.

  When winding the winding material 11 around the core 1, the winding start end of the winding material 11 is cut while inserting a cutting means such as a cutter blade into the blade insertion groove 3 to straighten the winding start portion. Is preferred.

<Explanation of terms>
“Sheet” generally refers to a product that is thin by definition in JIS and generally has a thickness that is small and flat for the length and width. A thin flat product with an extremely small thickness and an arbitrarily limited maximum thickness, usually supplied in the form of a roll (Japanese Industrial Standard JISK6900). For example, in terms of thickness, in the narrow sense, a film having a thickness of 100 μm or more is sometimes referred to as a sheet, and a film having a thickness of less than 100 μm is sometimes referred to as a film. However, since the boundary between the sheet and the film is not clear and it is not necessary to distinguish the two in terms of the present invention, in the present invention, even when the term “film” is used, the term “sheet” is included and the term “sheet” is used. In some cases, “film” is included.

In the present invention, when expressed as “X to Y” (X and Y are arbitrary numbers), “X is preferably greater than X” and “preferably Y”, with the meaning of “X to Y” unless otherwise specified. It is meant to include “less than”.
Further, in the present invention, when expressed as “more than X” (X is an arbitrary number), unless otherwise specified, it means “preferably greater than X” and includes “Y or less” (Y is an arbitrary number) When expressed as (numerical), it means “preferably smaller than Y” unless otherwise specified.

  Hereinafter, although an example is described, the present invention is not limited to this.

Example 1
As shown in FIGS. 1 and 2, adjacent to the winding surface of the winding start portion 1 </ b> A on the outer peripheral surface of a cylindrical core body 2 made of ABS resin and having a radius of 82.2 mm and a thickness of 6 mm. In addition, the cutting groove 3 is cut by an acrylic cutter over the entire width of the winding core body 2, and the step across the entire width of the winding core body 2 is positioned adjacent to the winding direction of the cutting groove 3 opposite to the winding direction. An absorbent member 4 is additionally provided, and a double-sided adhesive tape 5 having a width of 3 mm and a thickness of 0.05 mm is pasted over the entire width of the core body 2 at a position adjacent to the winding direction of the winding start portion 1A of the core body 2. The core 1 was formed.

The step absorbing member 4 was made of a polyolefin foam and had a flat rectangular parallelepiped shape, a thickness of 2.0 mm, a width of 20 mm, and a 25% compression hardness of 0.004 MPa.
Further, the blade insertion groove 3 was formed so that the depth direction was directed toward the center of the cylinder, and was formed into a slit groove shape having a groove width of 0.9 mm and a groove depth of 1.5 mm.

  Double-sided pressure-sensitive adhesive tape is used for the ends of the wound material 11 in which both sides of an acrylic pressure-sensitive adhesive sheet (thickness 0.175 mm, winding length 100 m) are covered with a release PET film (thicknesses 0.075 mm and 0.125 mm). 5 and the winding material 11 was wound around 165 times to produce a wound body 10.

  When this winding body 10 was visually observed for winding traces when unwound, step traces were confirmed for 29 laps (about 15 m). no problem.

(Comparative Example 1)
A cylindrical winding core made of ABS resin and having a radius of 82.2 mm and a thickness of 6 mm is prepared. At the position adjacent to the winding direction of the winding start portion of this winding core, in the same manner as in Example 1, the entire winding core width is set. A double-sided pressure-sensitive adhesive tape having a width of 3 mm and a thickness of 0.05 mm was pasted, and the winding material 11 was wound 165 times in the same manner as in Example 1 to prepare a wound body.
About this winding body, when the winding trace when unwinding was observed by visual observation similarly to Example 1, the level | step difference trace was recognized over 65 m.

DESCRIPTION OF SYMBOLS 1 Winding core 2 Winding core main body 3 Blade insertion groove | channel 4 Level | step difference absorption member 5 Adhesive member 10 Winding body 11 Winding material

Claims (4)

  A winding core having a configuration in which a step absorbing member is provided on the outer circumferential surface of the winding core on the side opposite to the winding direction of the winding start portion.   On the outer peripheral surface of the winding core, a blade cutting groove for film cutting is provided across the entire width of the winding core at a position adjacent to the winding side of the winding start portion on the opposite side, and the side opposite to the winding direction of the cutting groove A winding core having a configuration comprising a step absorbing member.   The core according to claim 1 or 2, wherein the step absorbing member is made of a foam. The winding body which has a structure formed by winding a winding material around the winding core according to claim 1.

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