JP3147706U - Winding core and film winding body using the same - Google Patents

Abstract

The present invention provides a winding core in which no stamp mark is formed on the film when the film is wound and held on the winding core, and a film winding body in which the film is wound using the winding core.
A present invention the core has a stepped portion extending in the longitudinal direction as a start point on the outer peripheral surface, a winding core for winding a film, a rising start point P ₁ of the step portion, When defining the end point P _{2 of the} stepped portion located farther from the axis P ₀ of the main core than the starting point P _{1, the} distance from the starting point P ₁ to the end point P ₂ so as to make the stepped portion gentle. peripheral line S _1-2 of the core is rounded.
[Selection] Figure 3

Description

  The present invention relates to a winding core and a film winding body using the winding core. More specifically, the present invention relates to a winding core suitable for winding a display member-forming film used for forming a display member such as a dielectric layer of a display panel, and a film winding body using the same.

  As an application requiring management of film smoothness, for example, a film for a plasma display panel (hereinafter also simply referred to as “PDP”) is known. Since the dielectric layer covering the cell electrode of the PDP affects the display of the PDP, it is necessary to highly manage the smoothness. This dielectric layer can be formed by a method of transferring a glass paste layer (inorganic particle-containing resin layer) formed on a support film, as disclosed in Patent Document 1 below. Similarly, a method of transferring a paste layer formed on a support film can also be used for parts such as electrodes and partition walls used in PDP. Films having these paste layers are usually distributed and managed as a film wound body wound around a winding core. However, since a high degree of smoothness management is required as described above, even in a wound state. An extremely high level of smoothness management is required.

JP-A-9-102273

  However, conventionally, when the film 20 is wound around the core 10 (see FIG. 17), a convex portion due to the thickness of the film 20 itself is generated, and this overlaps many times to form the convex portion 60 in the film winding body 30. Is formed. The film 20 positioned at the convex portion 60 is formed with a linear imprint 61 (see FIG. 18), and there is a problem that the smoothness of the film cannot be sufficiently maintained.

  The present invention solves the above-described problems, and a winding core in which no imprint is formed on the film even when the film is wound around and held by the winding core, and a film winding in which the film is wound using the winding core. The purpose is to provide a body.

That is, the present invention is as follows.
(1) A winding core for winding a film having a stepped portion extending in the longitudinal direction as a winding start point on the outer peripheral surface;
In a cross section perpendicular to the longitudinal direction of the winding core, a rising start point P ₁ of the step portion, and the end point P ₂ of the step portion which is farther from the shaft center P ₀ of the core than the starting point P ₁ when defining the, so as to smooth the stepped portion, the winding core, characterized in that the peripheral line S _1-2 of the winding core from the starting point P ₁ to the end point P ₂ is rounded .
(2) A line segment LS _0-1 connecting the axis center P ₀ and the starting point P ₁ and a line segment connecting the axis center P ₀ and the end point P ₂ in a cross section perpendicular to the longitudinal direction of the core. When LS _0-2 and the angle θ _1-2 formed by the line segment LS _0-1 and the line segment LS _0-2 are defined, the angle θ _1-2 is 0.05-3. The core according to claim 1, wherein the core is 0 degree.
(3) in the cross section perpendicular to the longitudinal direction of the winding core, the peripheral line _{S 1-2,} the winding core of claim 2 comprising a curve of radius of curvature 0.02 to 1.0 mm.
(4) in the cross section perpendicular to the longitudinal direction of the winding core, the peripheral line _{S 1-2} are straight line segments _{S 1-3} forming from the starting point _{P 1} to the end point _{P 2} to the headed changing point _{P 3} And a curve S _3-2 having a radius of curvature of 0.1 to 3.0 mm and extending from the change point P ₃ to the end point P ₂ .
(5) In a cross section perpendicular to the longitudinal direction of the core, the line segment LS _0-1 connecting the axis center P ₀ and the starting point P ₁ , the line segment LS _0-1, and the straight line segment S _1- 5. The core according to claim 4, wherein the angle θ _A is 10 to 80 degrees when the angle θ _A formed by ₃ is defined.
(6) A winding core for winding a film having a stepped portion extending in the longitudinal direction as a winding start point on the outer peripheral surface;
In a cross section perpendicular to the longitudinal direction of the winding core, a rising start point P ₁ of the step portion, and the end point P ₂ of the step portion which is farther from the shaft center P ₀ of the core than the starting point P ₁ when defining the with origin P ₁ the end point P ₂ to the outer peripheral line S _1-2 of the winding core forms from is formed by straight line segments, the peripheral line S _1-2 is, the stepped portion A winding core characterized by being inclined with respect to a line segment LS _0-1 connecting the axial center P ₀ of the main winding core and the starting point P ₁ so as to be gentle.
(7) In a cross section perpendicular to the longitudinal direction of the core, the line segment LS _0-1 connecting the axis center P ₀ and the starting point P ₁ , the line segment LS _0-1, and the outer peripheral line S _1- The winding core according to claim 6, wherein the angle θ _B is 10 to 80 degrees when the angle θ _B formed by ₂ is defined.
(8) A line segment LS _0-1 connecting the axis center P ₀ and the start point P ₁ and a line segment connecting the axis center P ₀ and the end point P ₂ in a cross section perpendicular to the longitudinal direction of the core. When LS _0-2 and the angle θ _1-2 formed by the line segment LS _0-1 and the line segment LS _0-2 are defined, the angle θ _1-2 is 0.05-3. The core according to claim 6 or 7, wherein the core is 0 degree.
(9) The present core is made of a main body made of a hard thermoplastic resin having a Rockwell R scale of 80 to 130 and a soft thermoplastic resin having a Shore A hardness of 30 to 95, and is joined to the main body. The core according to any one of claims 1 to 8, comprising the step portion.
(10) A winding core for winding a film, having a one-step perpendicular step portion extending in the longitudinal direction as a winding start point on the outer peripheral surface;
The main core is composed of a main body portion made of a hard thermoplastic resin having a Rockwell R scale of 80 to 130, and a step portion made of a soft thermoplastic resin having a Shore A hardness of 30 to 95 and joined to the main body portion. And a winding core characterized by comprising:
(11) A film winding body comprising: the core according to any one of claims 1 to 10; and a film wound around the core.
(12) The film roll according to claim 11, wherein the film is a display member forming film.
(13) The film roll according to claim 12, wherein the display member forming film has a support film layer and an inorganic particle-containing resin layer.
(14) The film roll according to claim 13, wherein the display member forming film has a resist layer between the support film layer and the inorganic particle-containing resin layer.

When the outer peripheral line _S1-2 is rounded so that the core according to the present invention gently smoothes the stepped portion, even when the film is wound around and held by the core, there is no trace on the film. It is not formed, and the smoothness of the wound film can be accurately maintained during transportation and storage.
When the angle θ _{1-2 of the} core is 0.05 to 3.0 degrees, an appropriate gap is obtained between the core and the film, so that a stamp mark is formed on the film. It can be effectively prevented.
If the radius of curvature of the peripheral line S _1-2 of the winding core is a curve of 0.02~1.0mm are traces push the film formation to moderate clearance is obtained between the core and the film Can be prevented more effectively.
Peripheral line _{S 1-2} of the core is, the straight line segment _{S 1-3,} the curve _{S 3-2} curvature radius 1.0 to 3.0 mm, if made of, between the core and the film Since an appropriate gap can be obtained, it is possible to more effectively prevent the formation of imprints on the film.
The outer circumference S _{1-2 of the} core is composed of a straight line S _1-3 and a curve S _3-2 having a curvature radius of 1.0 to 3.0 mm, and the angle θ _A is 10 to 80 degrees. In some cases, an appropriate gap is obtained between the core and the film, so that it is possible to more effectively prevent the formation of imprints on the film.
In the case where the winding core includes a hard main body and a soft stepped portion, the soft stepped portion can suppress the influence on the film due to the shape of the hard main body and can prevent imprinting on the film.

If winding core according to the present invention, together with peripheral line S _1-2 are formed by straight line segments, are inclined relative to the line segment LS _0-1 so as to smooth the step portion, winding the film Even when wound around a core and held, no trace is formed on the film, and the smoothness of the wound film can be accurately maintained during transportation and storage.
If the angle theta _B of the core is 10 to 80 degrees can prevent the mark push the film in order to moderate clearance is obtained between the core and the film is formed more effectively.
When the angle θ _{1-2 of the} core is 0.05 to 3.0 degrees, an appropriate gap is obtained between the core and the film, so that a stamp mark is formed on the film. It can be effectively prevented.
In the case where the winding core includes a hard main body and a soft stepped portion, the soft stepped portion can suppress the influence on the film due to the shape of the hard main body and can prevent imprinting on the film.

According to the film winding body which concerns on this invention, a press mark is not formed in a film, but the smoothness of a film can be correctly maintained during transport and storage.
In the case where the film is a display member forming film, excellent optical properties resulting from high smoothness can be obtained in a display using this film.
When the display member-forming film has a support film layer and an inorganic particle-containing resin layer, the smoothness of the inorganic particle-containing resin layer can be particularly favorably maintained, and the display using this film has a high smoothness. Excellent optical properties can be obtained.
When the display member-forming film has a resist layer between the support film layer and the inorganic particle-containing resin layer, the smoothness of each of the inorganic particle-containing resin layer and the resist layer can be maintained particularly well, and a display using this film Excellent optical properties resulting from high smoothness can be obtained.

Hereinafter, the core of the present invention and a film winding body using the core will be described with reference to FIGS.
In addition, in each figure, while showing the magnitude | size of the level | step-difference part 12, the thickness of the film 20, etc. exaggeratingly for easy understanding, in FIGS. 3-7, FIGS. 9-10, FIGS. In order to display the axial center P ₀ of the winding core 10 in the drawing, it is shown at a position closer to the step 12 than the actual position. Moreover, although the film 20 may be comprised from several layers, it has shown as a single layer for convenience. Further, in the cross-sectional views perpendicular to the longitudinal direction of the core shown in FIGS. 3 to 7, 9 to 10, and 11 to 12, the hatching indicating the cross section is provided only on the step portion 124 made of a soft thermoplastic resin. In addition, hatching of other parts is omitted because it is complicated in illustrating various symbols and auxiliary lines.

[1] of the core of the core present invention, (1-1) a first winding core, core step portion 12 becomes smooth by peripheral line S _1-2 are rounded (Fig. 3 ~ 8). Furthermore, (1-2) a second core is a core step portion 12 becomes smooth by peripheral line _{S 1-2} is tilted (Figure 9-11). Furthermore, (1-3) the third core is a core (FIG. 12) having a right-angle step formed from a soft material. Hereinafter, each of these winding cores will be described.

(1-1) First winding core (see FIGS. 1 to 8 and FIGS. 14 to 15)
Among the cores of the present invention, the first core 10 is
The outer peripheral surface 11 has a stepped portion 12 extending in the longitudinal direction as a winding start point, and is a winding core for winding a film,
In a cross section perpendicular to the longitudinal direction of the winding core 10, the rising start point P ₁ of the step portion 12, than said starting point P ₁ located far from the axial center P ₀ of the winding core 10 of the step portion 12 If you define the end point P _2, so as to smooth the stepped portion 12, that peripheral line S _1-2 of the winding core from the starting point P ₁ to the end point P ₂ is rounded Features.

In the first core 10, the step portion 12 is gently formed by rounding the outer peripheral line S _1-2 (the line segment S _1-2 forming the outer periphery of the main core) ( See FIGS. As a result, as illustrated in FIG. 8, a gap 15 is formed between the core 10 and the wound film 20, and no stamp mark is generated by the step portion 12.
This peripheral line _{S 1-2} of the first winding core 10 (line segment _{S 1-2} forming the outer periphery of the core), in order to take on the rounded, generally peripheral line _{S 1-2} is a curve segments Contains. The peripheral line _S1-2 may consist of (1) only one curve segment, (2) two or more curve segments, and (3) one curve segment and one line segment. (4) It may consist of two or more curved lines and one straight line, and (5) may include two or more straight lines.

Although not particularly limited size in the circumferential direction of the outer peripheral line S _1-2 (a direction around along the surface of the core), the line segment connecting the axial center P ₀ and the starting point P ₁ "LS _0-1" The line segment connecting the axis center P ₀ and the end point P ₂ is “LS _0-2 ”, and the angle formed by these line segments LS _0-1 and line segment LS _0-2 is “θ _1-2 ”. The angle θ _1-2 is preferably 0.05 to 3.0 degrees, and more preferably 0.1 to 1.0 degrees. In this range, an appropriate gap is obtained between the winding core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.

Among (1) to (5) of the peripheral line _{S 1-2,} the outer peripheral line _{S 1-2} in the form of (1) can be formed from one arc (see FIGS. 3 and 5-7 ). In this case, the arc is preferably a curve having a curvature radius of 0.02 to 1.0 mm, and more preferably 0.07 to 0.3 mm. In this range, an appropriate gap is obtained between the winding core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.
Furthermore, in this case, the angle θ _1-2 is preferably 0.05 to 3.0 degrees, and more preferably 0.1 to 1.0 degrees. In this range, an appropriate gap is obtained between the winding core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.
Further, when the line segment connecting the axis center P ₀ and the starting point P ₁ is “LS _0-1 ” and the line segment connecting the axis center P ₀ and the end point P ₂ is “LS _0-2 ”, min _{LS 0-2} is longer than the line segment _{LS 0-1,} the difference _T 2 -T ₁ and the length _{T 1} of the length of the line segment _{LS 0-2 T 2} and the line segment _{LS 0-1} is 0 0.02-1.0 mm is preferable, and 0.07-0.3 mm is more preferable. In this range, an appropriate gap can be obtained between the core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.

Also, out of the peripheral line _{S 1-2} (1) ~ (5), the outer peripheral line _{S 1-2} in the form of (3) can be formed from a single straight line and one curve (FIG. 4). In this case, the outer peripheral line _{S 1-2} is a straight line segment _{S 1-3} forming from the starting point _{P 1} to the end point _{P 2} change point _{P 3} toward the radius of curvature forms the transition points _{P 3} to the end point _{P 2} 0 It is preferable that the curve S _{3-2 has a} thickness of 1 to 3.0 mm. The radius of curvature is more preferably 0.5 to 1.5 mm. In this range, an appropriate gap can be obtained between the core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.
The angle θ _1-2 is preferably 0.05 to 3.0 degrees, and more preferably 0.1 to 1.0 degrees. In this range, an appropriate gap can be obtained between the core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.

Furthermore, in the form illustrated in FIG. 4, the line segment connecting the axis center P ₀ and the starting point P ₁ is “LS _0-1 ”, and the line segment LS _0-1 and the straight line segment S _{1-3 are} formed. When the angle is “θ _A ”, the angle θ _A is preferably 10 to 80 degrees, and more preferably 40 to 75 degrees. In this range, an appropriate gap can be obtained between the core and the film, and the formation of a stamp mark on the film can be more effectively prevented.
The difference _T 2 -T ₁ and the length _{T 1} of the length of the line segment _{LS 0-2 T 2} and the line segment _{LS 0-1} is, 0.02 to 1.0 mm is preferable, 0.07 to 0 .3 mm is more preferable. In this range, an appropriate gap can be obtained between the core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.

  Further, the outline of the first core 10 is not particularly limited as long as the outer periphery is substantially circular. For example, the winding core 10 may have a columnar shape (solid shape) or a cylindrical shape. Of these, a cylindrical shape is preferable. In the case of a cylindrical shape, the size and dimensions of each part are not particularly limited, but the length can be 5 to 2500 mm (particularly 200 to 1800 mm). Moreover, the outer diameter in the site | part which does not include the level | step-difference part 12 of the core 10 can be 71-190 mm (especially 80-94 mm). The inner diameter can be 65 to 160 mm (particularly 74 to 78 mm). Furthermore, the thickness in the site | part which does not contain the level | step-difference part 12 of the core 10 can be 3-15 mm (especially 3-8 mm). Note that the length and the outer diameter are also applied to a cylindrical shape.

Moreover, the material which comprises a 1st winding core is although it does not specifically limit, Usually, it consists of a hard thermoplastic resin whose Rockwell R scale (conforms to JIS K7202-2, and the same below) is 80-130. Examples of such thermoplastic resins include olefin resins (polyethylene, polypropylene, etc.), styrene resins (ABS resin, AES resin, AS resin, MBS resin, polystyrene, etc.), polyvinyl chloride, vinylidene chloride resin, methacrylic resin. , Polyvinyl alcohol, styrene block copolymer resin, polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polyester (polybutylene terephthalate, polyethylene terephthalate, etc.), fluorine resin, polyphenylene sulfide, polysulfone, amorphous polyarylate, polyetherimide, polyether Examples include sulfone, polyether ketones, liquid crystal polymers, polyamideimides, thermoplastic polyimides, and syndio-type polystyrene. These may use only 1 type and may use 2 or more types together. Among these, ABS resin and vinyl chloride resin are preferable, and ABS resin is more preferable. The Rockwell R scale is more preferably 85 to 125, and still more preferably 85 to 120.
The core 10 and the stepped portion 12 may be formed in any manner, and it is preferable to use an appropriate method depending on the above-mentioned various materials. Usually, extrusion molding or cutting molding may be used. it can.

  The first winding core 10 may be integrally formed from a hard thermoplastic resin (see FIGS. 3 and 4), but the hard heat of the Rockwell R scale 80 to 130 is used. A core provided with a main body portion 13 made of a plastic resin and a step portion 12 made of a soft thermoplastic resin (for example, Shore A hardness 30 to 95, conforming to JIS K6253, the same applies hereinafter) and joined to the main body portion 13. 10 (see FIGS. 5 to 7). That is, only the step portion 12 (124) or a part of the core including the step portion 12 (124) is formed from a soft thermoplastic resin, and the core 10 can be joined to the main body portion 13. By setting it as such a structure, the soft step part 124 can suppress the influence on the film by the outer periphery shape of the hard main-body part 13, and can prevent the trace to a film more effectively.

  5-7 are illustrated as an example provided with the level | step-difference part 12 (124) formed from the said soft thermoplastic resin. FIG. 5 shows a form in which a new step portion 124 made of a soft plastic resin having a rounded shape is joined to a step portion of a core (main body portion 13) having a right-angle step portion. The core 10 of this form can be formed using a conventional form of the core (FIG. 13). Further, FIG. 6 shows that the bonding area between the main body 13 and the stepped portion 124 is increased so that a part of the stepped portion 124 is placed in the main body 13 so that the main body 13 and the stepped portion 124 are bonded more firmly. It is the form joined so that it may be embedded in. Furthermore, FIG. 7 shows a form in which the bottom area of the step portion 124 is increased and joined to the main body portion 13 so that the main body portion 13 and the step portion 124 are more firmly joined.

The step portion 124 made of the soft thermoplastic resin may be a solid body (non-foamed material) made of a thermoplastic resin or a foamed material.
Further, as the soft thermoplastic resin, a thermoplastic elastomer is usually used. Thermoplastic elastomers include styrene thermoplastic elastomers, polyolefin thermoplastic elastomers, dynamically cross-linked polyolefin thermoplastic elastomers, polyvinyl chloride thermoplastic elastomers, polyurethane thermoplastic elastomers, polyester thermoplastic elastomers, polyamides Examples include thermoplastic elastomers, acrylic thermoplastic elastomers, 1,2-polybutadiene thermoplastic elastomers, and the like. These may use only 1 type and may use 2 or more types together. The Shore A hardness is more preferably from 30 to 95, still more preferably from 60 to 90.

  In the winding core 10 having the hard main body 13 and the soft stepped portion 124 as described above, the film winding start point or the film winding point can be changed by changing the color of each thermoplastic resin forming the main body 13 and the stepped portion 124. The end point can be made easier to understand. Each color may be the original color of each thermoplastic resin, or a colorant may be mixed.

The method for forming the first winding core is not particularly limited, and the main body portion excluding the step portion 12 (step portion formed integrally with the hard main body portion) and the main body portion 13 (soft step portion 124). ) May be formed in any manner, and it is preferable to use an appropriate method depending on the various materials. Among these, a hard main-body part can be obtained by extrusion molding or cutting molding as mentioned above. On the other hand, the soft stepped portion 124 can be obtained by extrusion molding or press molding. Furthermore, in the core having the hard main body portion 13 and the soft stepped portion 124, each can be molded by separate molding methods. However, when both are performed by extrusion molding, The melted hard main body portion 13 and the melted soft stepped portion 124 can be merged, joined, integrated, and extruded in the mold. Further, the temporary molding step and the integration step may be performed discontinuously, but each of the temporarily molded hard main body portion 13 and soft stepped portion 124 is melted (melting enough to maintain the form). While maintaining the (state), both can be melt-bonded by continuously shifting to the integration step.
In the first core, since the stepped portion 12 is gentle, the handleability is further improved and safe particularly when the stepped portion is made of a soft thermoplastic resin.

  As illustrated in FIG. 14, the first core 10 of the present invention can be provided with an identification mark 40 indicating the film winding start point or film winding end point on the outer peripheral surface of the core 10. By providing this identification mark 40, the winding start point or the winding end point can be easily identified. The identification mark 40 may be printed directly on the outer surface 11 of the core 10 or may be formed by a seal member or the like. Moreover, the formation position of the identification mark 40 should just be a site | part which can discriminate | determine the position of the level | step-difference part 12, for example, can be formed in the lower step surface 121 of the level | step-difference part 12 so that it may illustrate. In addition, you may form in the upper stage surface 122 of the level | step-difference part 12, and may form in the side surface 123 of the core 10 further.

(1-2) Second winding core (see FIGS. 1-2, 9-11, 14-15)
Among the cores of the present invention, the second core 10 is
The outer peripheral surface 11 has a stepped portion 12 extending in the longitudinal direction as a winding start point, and is a winding core for winding a film,
In a cross section perpendicular to the longitudinal direction of the winding core 10, the rising start point P ₁ of the step portion 12, than said starting point P ₁ located far from the axial center P ₀ of the winding core 10 of the step portion 12 If you define the end point _{P 2,} together with the peripheral line _{S 1-2} of the present core 10 forming from the starting point _{P 1} to the end point _{P 2} is formed by straight line segments, said peripheral line _{S 1-2} The step portion 12 is inclined with respect to a line segment LS _0-1 connecting the axial center P ₀ of the main core 10 and the starting point P ₁ so as to make the stepped portion 12 gentle.

Unlike the first winding core, the second winding core 10 does not include a curve in the outer circumferential line S _1-2 (the line segment S _1-2 forming the outer circumference of the main winding core), but the outer circumferential line S _The step portion 12 is gently formed by the _1-2 being inclined with respect to the line segment LS _0-1 . As a result, as illustrated in FIG. 11, a gap 15 is formed between the core 10 and the wound film 20, and no stamp mark is generated by the step portion 12.
In the core 10, the line segment connecting the axis center P ₀ and the starting point P ₁ is “LS _0-1 ”, and the angle formed by the line segment LS _0-1 and the outer circumferential line S _1-2 is “θ _In the case of “ _B ”, the angle θ _B is preferably 10 to 80 degrees, and more preferably 40 to 75 degrees. In this range, an appropriate gap can be obtained between the core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.

Furthermore, the winding core 10, the axial center _{P 0} and the line segment connecting the end point _{P 2} as _{"LS 0-2",} the line segment _{LS 0-1} and the angle formed by the line segment _{LS 0-2} "theta _{1 −2} ”, the angle θ _1-2 is preferably 0.05 to 3.0 degrees, more preferably 0.05 to 1.5 degrees. In this range, an appropriate gap can be obtained between the core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.
The difference _T 2 -T ₁ and the length _{T 1} of the length of the line segment _{LS 0-2 T 2} and the line segment _{LS 0-1} is, 0.02 to 1.0 mm is preferable, 0.07 to 0 .3 mm is more preferable. In this range, an appropriate gap can be obtained between the core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.
In addition, about the general form of these 2nd cores 10, the description in a 1st core is applicable as it is.

Further, the second core 10 may be integrally formed from a hard thermoplastic resin (see FIG. 9), but, like the first core, the Rockwell R scale is A core 10 having a main body portion 13 made of 80 to 130 hard thermoplastic resin and a step portion 12 made of a soft thermoplastic resin having a Shore A hardness of 30 to 95 and joined to the main body portion 13 (FIG. 10). Reference). That is, only the stepped portion 12 (124) is formed from a soft thermoplastic resin, and the core 10 can be formed by joining the stepped portion 12 (124) to the main body portion 13. By setting it as such a structure, the soft step part 124 can suppress the influence on the film by the outer periphery shape of the hard main-body part 13, and can prevent the trace to a film more effectively.
As the hard thermoplastic resin and the soft thermoplastic resin, each thermoplastic resin described in the first core can be similarly applied to the second core.

Further, in the embodiment including the main body portion 13 and the step portion 124 joined to the main body portion 13 (see FIG. 10), the main body portion 13 and the step portion 124 are joined in a cross section perpendicular to the longitudinal direction of the main core 10. the line segment connecting the starting point _{P 1} and the shaft center _{P 0} which is one end of the boundary line _{L C} forming the surface as _{"LS 0-1",} the _{P 4} and the axial center point _{P 0,} which is the other end of the boundary line _{L C} When the connecting line segment is “LS _0-4 ” and the line segment connecting the axis center P ₀ and the end point P ₂ is “LS _0-2 ”, the length T ₂ of the line segment LS _0-2 and the line segment The difference T ₂ -T _{1 from} the length T _{1 of} LS _0-1 is preferably 0.02 to 1.0 mm, and more preferably 0.07 to 0.3 mm. The difference T ₄ -T ₁ between the length T ₄ of the line segment LS _{0-4 and} the length T ₁ of the line segment LS _0-1 is preferably 0.01 to 1.0 mm, and preferably 0.05 to 0. .25 mm is more preferable. In this range, an appropriate gap can be obtained between the core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.

In the core 10 including the hard main body 13 and the soft stepped portion 124 as described above, the color of each thermoplastic resin forming the main body portion 13 and the stepped portion 124 is set in the same manner as the first core. By making a difference, the winding start point or end point of the film can be made easier to understand. Each color may be the original color of each thermoplastic resin, or a colorant may be mixed.
Further, the winding core and the method of forming each part thereof are the same as those of the first winding core. In addition, even in the second core, the stepped portion 12 is gentle, so that the stepped portion is made of a soft thermoplastic resin.
Also, the second winding core 10 of the present invention can be provided with the identification mark 40 as in the first winding core. For the identification mark 40, the description of the identification mark 40 in the first winding core can be applied as it is.

(1-3) Third winding core (see FIGS. 1-2, 12 and 14-15)
Among the cores of the present invention, the third core 10 is
A winding core for winding a film, having a single-step "right angle" step portion 12 extending in the longitudinal direction as a winding start point on the outer peripheral surface 11,
The main core 10 is composed of a main body 13 made of a hard thermoplastic resin having a Rockwell R scale of 80 to 130, a soft thermoplastic resin having a Shore A hardness of 30 to 95, and joined to the main body. And a step portion 124.

In the third winding core, further, in a cross section perpendicular to the longitudinal direction of the winding core 10, the body portion 13 and the starting point P ₁ and the shaft center which is one end of the boundary line L _C constituting the bonding surface between the stepped portion 124 A line segment connecting P ₀ is “LS _0-1 ”, a line segment connecting the point P ₄ that is the other end of the boundary line L _C and the axis center P ₀ is “LS _0-4 ”, and the axis center P ₀ and When the line segment connecting the end points P ₂ is “LS _0-2 ”, the difference T ₂ −T ₁ between the length T ₂ of the line segment LS _{0-2 and} the length T ₁ of the line segment LS _0-1 Is preferably 0.02 to 1.0 mm, and more preferably 0.07 to 0.3 mm. The difference T ₄ -T ₁ between the length T ₄ of the line segment LS _{0-4 and} the length T ₁ of the line segment LS _0-1 is preferably 0.01 to 1.0 mm, and preferably 0.05 to 0. .25 mm is more preferable. In this range, an appropriate gap can be obtained between the core and the film, and it is possible to more effectively prevent the formation of a stamp mark on the film.

In addition, about the general form of these 3rd cores 10, the description in a 1st core is applicable as it is. Furthermore, for the hard thermoplastic resin that constitutes the main body 13 and the soft thermoplastic resin that constitutes the stepped portion 124, the descriptions in the first core can be applied as they are.
Furthermore, the same applies to the fact that the winding start point or end point of the film can be made easier to understand by changing the color of the thermoplastic resin that forms the main body 13 and the stepped portion 124. The forming method and the like are the same as those of the first core. In addition, in the third core, although the step portion 12 is a right angle, since the step portion is made of a soft thermoplastic resin, it is safe and easy to handle.
Further, the third winding core 10 of the present invention can also be provided with an identification mark 40 in the same manner as the first winding core. For the identification mark 40, the description of the identification mark 40 in the first winding core can be applied as it is.

[2] Film Winding Body The film winding body 30 of the present invention includes the core 10 of the present invention and the film 20 wound around the core 10 (FIGS. 8 and 11). FIG. 15).

The various cores 10 of the present invention can be applied to the core 10 as they are. On the other hand, the kind of the film 20 which comprises the film winding body of this invention is not specifically limited. Examples of the film 20 include an optical film (display member forming film and the like), a packaging film, a transfer film, a protective film, a conductive film, a printed wiring board film, a photosensitive film, a weather resistant film, and the like.
Among these, an optical film is preferable, and further, a display member forming film is preferable from the viewpoint of effectively utilizing the characteristic of the core 10 of the present invention that the smoothness of the film can be maintained with high accuracy.

  The display member-forming film may be a display for any application, and the type thereof is not particularly limited, and examples thereof include a plasma display panel and a field emission display panel. Specific examples of the display member include a dielectric layer, a partition, an electrode, a phosphor, a resistor, a color filter, and a black matrix.

  Although the thickness of this display member formation film is not specifically limited, Usually, it is 250 micrometers or less (preferably 100-200 micrometers, More preferably, it is 130-180 micrometers). Further, the width of the display member-forming film is not particularly limited, but is usually 50 to 100% (preferably 70 to 99%, more preferably 75 to 95%) of the width (length) of the core. preferable.

  The display member-forming film usually comprises a support film layer and an inorganic particle-containing resin layer formed on the surface of the support film. This inorganic particle-containing resin layer may be a single layer or may be formed of a plurality of layers having different compositions. Moreover, although the film for display member formation may consist only of a support film layer and an inorganic particle containing resin layer, for example, a protective film layer etc. which protect an inorganic particle containing resin layer can be provided. A film for forming a display panel having a protective film layer can be provided by laminating a support film layer, an inorganic particle-containing resin layer, and a protective film layer in this order. Furthermore, the film for forming a display member can include a resist layer. When a resist layer is provided, a resist layer can be provided between the support film layer and the inorganic particle-containing resin layer. Furthermore, other layers such as an antireflection layer can be provided.

  The support film is preferably a resin film having heat resistance and solvent resistance and flexibility. Since the support film has flexibility, the inorganic particle-containing resin layer can be applied and formed by a roll coater, a blade coater, or the like, and can be wound around a core to preserve the state. The resin species constituting the support film is not particularly limited, and various thermoplastic resins mentioned as the thermoplastic resin constituting the winding core can be applied as they are. Among them, polyester (particularly polyethylene terephthalate), polyolefin, polystyrene, polyimide, polyvinyl alcohol, fluororesin, polyamide, and the like can be used, and among them, polyethylene terephthalate is preferable. These resins may be used alone or in combination of two or more. The thickness of this support film is not particularly limited, but can be 20 to 100 μm.

  The inorganic particle-containing resin layer is a layer having plastic deformability, and usually contains inorganic particles and a binder resin. The method for forming the inorganic particle-containing resin layer is not particularly limited. For example, after applying a paste composition containing inorganic particles, a binder resin and a solvent (hereinafter also simply referred to as “inorganic paste”) on a support film. It can be obtained by drying and removing part or all of the solvent.

The inorganic substance which comprises the said inorganic particle is not specifically limited, According to the use (type of display member) of the sintered compact formed, it can select suitably.
The inorganic particles used in the inorganic particle-containing resin layer for forming the “dielectric layer” and the “partition wall” constituting the PDP, flat panel display (hereinafter simply referred to as “FPD”) and the like have a softening point of 400 to 400. Examples include glass particles at 600 ° C. Examples of such glass particles include PbO—B ₂ O ₃ —SiO ₂ —CaO glass particles, ZnO—B ₂ O ₃ —SiO ₂ glass particles, PbO—B ₂ O ₃ —SiO ₂ —Al ₂ O _3. System glass particles, PbO—ZnO—B ₂ O ₃ —SiO ₂ glass particles, and the like. These may use only 1 type and may use 2 or more types together.

The average particle diameter of the glass particles is preferably 0.5 to 3 μm (more preferably 1 to 2.5 μm). The particle size distribution is preferably such that the proportion of particles having a particle size of 10 μm or more is 10% by mass or less, and further the proportion of particles having a particle size of 0.7 to 2.5 μm is 40% by mass or more. It is preferable. Moreover, it is preferable that a BET specific surface area is 1.0-5.5 m < ² > / g.
These glass particles may be contained (combined) in an inorganic particle-containing resin layer for forming a display member other than the dielectric layer and the partition. The content of the glass particles in the inorganic particle-containing resin layer for obtaining these display members is usually 90% by mass or less, preferably 50 to 90% by mass with respect to the total amount of the inorganic particles.

As the inorganic particles used in the resin layer containing inorganic particles for forming the “electrode” constituting PDP, FPD, etc., metal particles made of Ag, Au, Al, Ni, Ag—Pd alloy, Cu, Cr and the like are used. Can be mentioned.
Examples of the inorganic particles used in the inorganic particle-containing resin layer for forming the “resistor” constituting the PDP include particles made of RuO ₂ or the like.
As inorganic particles used in the inorganic particle-containing resin layer for forming the “phosphor” constituting the PDP, Y ₂ O ₃ : Eu ³⁺ , Y ₂ SiO ₅ : Eu ³⁺ , Y ₃ Al ₅ O ₁₂ : Eu ³⁺ , YVO ₄ : Eu ³⁺ , (Y, Gd) BO ₃ : Eu ³⁺ , Zn ₃ (PO ₄ ) ₂ : red fluorescent material such as Mn; Zn ₂ SiO ₄ : Mn, BaAl ₁₂ O ₁₉ : Mn, BaMgAl ₁₄ O ₂₃ : Mn, LaPO ₄ : (Ce, Tb), Y ₃ (Al, Ga) ₅ O ₁₂ : Green phosphor such as Tb; Y ₂ SiO ₅ : Ce, BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , BaMgAl ^{_{14 O 23: Eu 2+, (}} Ca, Sr, Ba) 10 (PO 4) 6 Cl 2: Eu 2+, (Zn, Cd) S: particles made of a blue fluorescent substance such as Ag It can be mentioned.
The inorganic particles used in the inorganic particle-containing resin layer for forming the “color filter” constituting the PDP include red materials such as Fe ₂ O ₃ and Pb ₃ O ₄ , and green materials such as Cr ₂ O _3. Examples thereof include particles made of a blue substance such as 2 (Al ₂ Na ₂ Si ₃ O ₁₀ ) · Na ₂ S ₄ .
Examples of the inorganic particles used in the inorganic particle-containing resin layer for forming the “black matrix” constituting the PDP include particles made of Mn, Fe, Cr, and the like.
The content of these inorganic particles is usually 50% by mass or more based on the entire inorganic particle-containing resin layer.

The kind of the binder resin is not particularly limited, and various binder resins used for the inorganic paste can be used, and among them, an acrylic resin is preferable. In particular, an acrylic resin that is completely removed by burning at a baking temperature of 400 to 600 ° C. is preferable. Furthermore, the molecular weight of the acrylic resin is preferably 2,000 to 300,000 (more preferably 5,000 to 200,000) as a weight average molecular weight in terms of polystyrene by GPC. Further, when pattern formation is performed by alkali development (alkali etching) when forming the display member, the binder resin needs to be an alkali-soluble resin. Although content of this binder resin is not specifically limited, It is preferable that it is 5-40 mass parts (more preferably 10-30 mass parts) with respect to 100 mass parts of inorganic particles.
Further, the inorganic particle-containing resin layer may have photosensitivity. In this case, the photosensitive inorganic particle-containing resin layer usually contains a photopolymerization initiator and a photosensitive monomer in addition to the inorganic particles and the binder resin. Known photopolymerization initiators can be appropriately used. Moreover, as a photosensitive monomer, although a well-known thing can be used suitably, it is preferable to use a polyvalent (meth) acrylate.

  The inorganic particle-containing resin layer can be obtained by applying an inorganic paste on a support film and then drying the inorganic paste by adding a solvent to the inorganic paste as described above. The type of this solvent is not particularly limited, but ketones such as diethyl ketone, methyl butyl ketone, dipropyl ketone, and cyclohexanone; alcohols such as n-pentanol, 4-methyl-2-pentanol, cyclohexanol, and diacetone alcohol Ether ether alcohols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; saturated aliphatic monocarboxylic acids such as n-butyl acetate and amyl acetate Acid alkyl esters; lactic acid esters such as ethyl lactate and lactic acid-n-butyl; methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether Seteto, ether esters such as ethyl 3-ethoxypropionate, and the like. These may use only 1 type and may use 2 or more types together. Although content of the solvent in an inorganic particle containing resin layer is not specifically limited, It is preferable that it is 0.1-2 mass% with respect to the whole inorganic particle containing resin layer.

Furthermore, the inorganic particle-containing resin layer can contain a silane coupling agent. When the silane coupling agent is contained, the content is not particularly limited, but 0.001 to 10 parts by mass (more preferably 0.001 to 5 parts by mass) is contained with respect to 100 parts by mass of the inorganic particles. preferable.
The inorganic particle-containing resin layer can contain a plasticizer. Plasticizers include dibutyl adipate, diisobutyl adipate, di-2-ethylhexyl adipate, di-2-ethylhexyl azelate, dibutyl sebacate, dibutyl diglycol adipate, and propylene glycol (propylene glycol monolaurate, propylene glycol monooleate, etc. ) And the like. These may use only 1 type and may use 2 or more types together. When a plasticizer is contained, the content is not particularly limited, but is preferably 0.1 to 20 parts by mass (more preferably 0.5 to 10 parts by mass) with respect to 100 parts by mass of the inorganic particles.
In addition to the above components, the inorganic particle-containing resin layer can contain other components. Examples of other components include a dispersant, a tackifier, a surface tension adjuster, a stabilizer, and an antifoaming agent. These may use only 1 type and may use 2 or more types together.

In addition, the core 10 and the film 20 may be joined using a joining member or may not be joined. For example, the step portion 12 of the core via the joining member at the end of the film. Can be bonded to the lower step surface 121.
The type of the bonding member is not particularly limited, and various bonding members can be used. For example, an adhesive, a pressure-sensitive adhesive, and a double-sided tape can be used. These may use only 1 type and may use 2 or more types together. Moreover, this joining member may join the full length of the width direction of a film to a core, and may join only one part.

  Hereinafter, although this invention is demonstrated using a figure and an Example, this invention is not limited by these. In the following, “part” means “part by mass”. Moreover, the evaluation method in an Example uses the method shown below.

(1) Manufacture of winding core (1-1) Embodiments 1 to 3, Comparative Example 1
Using ABS resin (Rockwell R scale 110), the inner diameter is 76.0 mm (± 0.2 mm), the outer diameter is 84.0 mm (± 0.3 mm), and the length is 1550 mm (± 2.0 mm) by extrusion molding. And cylindrical shapes each having a step portion shown below are formed, and these cylindrical tubes are used as Embodiments 1 to 3 and Comparative Example 1.
(1-2) Comparative Example 2
Using ABS resin (Rockwell R scale 110), the inner diameter is 76.0 mm (± 0.2 mm), the outer diameter is 84.0 mm (± 0.3 mm), and the length is 1550 mm (± 2.0 mm) by extrusion molding. A cylindrical shape having no step portion is formed, and this cylindrical tube is used as Comparative Example 2.

(1-3) Embodiments 4 to 5
ABS resin (Rockwell R scale 110) is used as the hard thermoplastic resin constituting the main body 13, and polyurethane thermoplastic elastomer (Shore A hardness 70) is used as the soft thermoplastic resin constituting the stepped portion 124. The shapes of the main body 13 and the stepped portion 124 are merged and integrated in the mold, the inner diameter is 76.0 mm (± 0.2 mm), the outer diameter is 84.0 mm (± 0.3 mm), and the length is 1550 mm. (± 2.0 mm), each of which has a stepped portion shown below, is formed into a cylindrical shape, and these cylindrical tubes are used as Embodiments 4 to 5.

[Embodiment 1]
The core 10 has a stepped portion 12 having a cross-sectional shape shown in FIG. 3 and has a specific form shown below.
Curvature of the S _1-2 radius = 0.18mm
θ _1-2 = 0.25 degree LS _0-1 length = 41.8 mm
LS _0-2 length = 42.0mm

[Embodiment 2]
The core 10 has a stepped portion 12 having a cross-sectional shape shown in FIG. 4 and has a specific form shown below.
S _3-2 radius of curvature = 1.0 mm
θ _1-2 = 0.85 degrees θ _A = 60 degrees Length of LS _0-1 = 41.8 mm
LS _0-2 length = 42.0mm

[Embodiment 3]
It is the core 10 which has the level | step-difference part 12 of the cross-sectional shape shown in FIG. 9, and has the specific form shown below.
θ _1-2 = 0.47 degrees θ _B = 60 degrees Length of LS _0-1 = 41.8 mm
LS _0-2 length = 42.0mm

[Embodiment 4]
The core 10 has a stepped portion 12 having a cross-sectional shape shown in FIG. 10 and has a specific form shown below.
θ _1-2 = 0.47 degrees θ _B = 60 degrees Length of LS _0-1 = 41.8 mm
LS _0-2 length = 42.0mm
LS _0-4 length = 42.0mm

[Embodiment 5]
The core 10 has a stepped portion 12 having a cross-sectional shape shown in FIG. 12 and has a specific form shown below.
LS _0-1 length = 41.8mm
LS _0-2 length = 42.0mm
LS _0-4 length = 42.0mm

[Comparative Example 1]
It is the core 10 which has the substantially right-angled level | step-difference part which consists of the same ABS as the main-body part shown in FIG. 13, and has the concrete form shown below.
LS _0-1 length = 41.8mm
LS _0-2 length = 42.0mm
[Comparative Example 2]
This is a winding core made of a cylindrical tube having no stepped portion.

(2) Production of Display Member Forming Film On the other hand, 100 parts of the following glass particles, 23 parts of the following binder resin, 1 part of the following silane coupling agent, 3 parts of the following plasticizer, and 7 parts of the following solvent are kneaded using a disperser. Then, using a roll coater, a support film (width 400 mm, length 100 m, thickness 38 μm) made of polyethylene terephthalate (PET) obtained by releasing the inorganic paste (glass paste) prepared to have a viscosity of 2,000 cps was applied. To do. Thereafter, the formed coating film is dried at 100 ° C. for 5 minutes to obtain an inorganic particle-containing resin layer having a thickness of 50 μm. Next, a protective film having a thickness of 25 μm (other dimensions are the same as those of the support film) is pressure-bonded onto the inorganic particle-containing resin layer to produce a display member forming film (PDP dielectric layer forming film) having a length of 100 m. The surface of the inorganic particle-containing resin layer of the obtained film is observed with an optical microscope, and it is confirmed that there are no film defects such as aggregation of glass particles, streaky coating marks, craters and pinholes.

Glass particles: PbO—B ₂ O ₃ —SiO ₂ —CaO-based glass particles
{PbO / B ₂ O ₃ / SiO ₂ / CaO = 60/10/25/5 (mass ratio)}
Binder resin: Acrylic resin {Copolymerization ratio: Butyl methacrylate / Hydroxypropylene
Dimethacrylate = 70/30 (mass ratio, Mw: 80,000}
Silane coupling agent: n-butyltrimethoxysilane Plasticizer: Propylene glycol monooleate (propylene glycol and olei
Ester compound with acid)
Solvent: Propylene glycol monomethyl ether

(3) Winding of display member forming film A double-sided tape having a thickness of 10 μm is attached to the lower surface 121 of each step 12 of each of the seven types of cores 10 obtained in (1) above in the center in the width direction over a length of 100 mm. . Thereafter, the support film layer of the display panel film obtained in the above (2) is attached to the stepped portion 12 and then joined to the double-sided tape, and then the display member forming film on the core 12 with a winding tension of 150 N / m. 20 is wound into 1,000 layers, and the film winding body 30 is formed.
In addition, the film winding body 30 is formed in the same manner except that the winding core of Comparative Example 2 does not have the step portion 12.

(4) Evaluation of film after being held wound After the display member forming film 20 wound around the film wound body 30 obtained in the above (3) is stored at 25 ° C. for one month, the film wound body 30 While confirming the appearance, all the film 20 is rewound from the core 12. Thereafter, the state of the inorganic particle-containing resin layer is visually observed from the surface of the rewound display member forming film 20.

As a result, in the film roll 30 using the core 10 of Comparative Example 1, as shown schematically in FIG. 16, in a combination in which the thickness of the film 20 and the height of the stepped portion 12 do not completely match, A thin imprint is confirmed in the inorganic particle-containing resin layer of the film 20 about 10 m from the beginning of winding.
Moreover, in the film winding body 30 using the core 10 of the comparative example 2, as shown schematically in FIG. 17, the protruding convex portion 60 is recognized due to the thickness of the lowermost film 20. It is done. Furthermore, as shown schematically in FIG. 18, the film 20 that has been rewound has an impression 61 that allows the appearance to be confirmed, and a strong impression is confirmed on the inorganic particle-containing resin layer of the film 20 about 20 m from the beginning of winding. .
On the other hand, in the cores of Embodiments 1 to 5, as schematically shown in FIG. 8 (corresponding to Embodiments 1 and 2) and FIG. 11 (corresponding to Embodiments 3 and 4). In addition, the film winding body 30 has no protrusions, and the inorganic particle-containing resin layer of the film 20 has no impressions.

The perspective view of an example of a core. Sectional drawing of an example of a core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of an example (Embodiment 1) of a 1st core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of an example (Embodiment 2) of a 1st core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of an example of a 1st core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of an example of a 1st core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of an example of a 1st core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of the film winding body using a 1st core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of an example (Embodiment 3) of a 2nd core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of an example (Embodiment 4) of a 2nd core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of the film winding body using a 2nd core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of an example (Embodiment 5) of a 3rd core. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of an example (comparative example 1) of a winding core of a comparative product. The perspective view of an example of a core provided with the identification mark which concerns on this invention. The perspective view of an example of the film winding body which concerns on this invention. Explanatory drawing which shows the cross section of the level | step-difference part vicinity of the film winding body of the former (comparative example 1). Explanatory drawing which shows the cross section of the winding start point vicinity of the film winding body of the former (comparative example 2). Explanatory drawing of the mode of the press mark recognized when a film is rewound from the conventional film winding body.

Explanation of symbols

  10; winding core, 11; outer peripheral surface, 12; stepped portion, 121; lower stepped surface, 122; upper stepped surface, 123; side surface, 124; stepped portion made of soft thermoplastic resin, 13; body portion, 15; 20; Film, 30; Film wound body, 40; Identification mark, 60; Convex part, 61;

Claims (14)

A winding core for winding a film having a stepped portion extending in the longitudinal direction as a winding starting point on the outer peripheral surface,
In a cross section perpendicular to the longitudinal direction of the winding core, a rising start point P ₁ of the step portion, and the end point P ₂ of the step portion which is farther from the shaft center P ₀ of the core than the starting point P ₁ when defining the, so as to smooth the stepped portion, the winding core, characterized in that the peripheral line S _1-2 of the winding core from the starting point P ₁ to the end point P ₂ is rounded . In a cross section perpendicular to the longitudinal direction of the core, a line segment LS _0-1 connecting the axis center P ₀ and the start point P ₁ and a line segment LS _0- connecting the axis center P ₀ and the end point P ₂ are used. ₂ and the angle θ _1-2 formed by the line segment LS _0-1 and the line segment LS _0-2 , the angle θ _1-2 is 0.05 to 3.0 degrees. The core according to claim 1. In a cross section perpendicular to the longitudinal direction of the winding core, the peripheral line _{S 1-2,} the winding core of claim 2 comprising a curve of radius of curvature 0.02 to 1.0 mm. In the cross section perpendicular to the longitudinal direction of the winding core, the peripheral line S _1-2 is a straight line segment S _1-3 forming from the starting point P ₁ to the end point P ₂ change point P ₃ toward the The winding core according to claim 2, comprising: a curve S _3-2 having a radius of curvature of 0.1 to 3.0 mm that forms the transition point P ₃ to the end point P ₂ . In the cross section perpendicular to the longitudinal direction of the core, the line segment LS _0-1 connecting the axis center P ₀ and the starting point P ₁ , the line segment LS _0-1, and the straight line segment S _{1-3 are} formed. when defined as the angle theta _a which is a, the angle theta _a is winding core according to claim 4 which is 10 to 80 degrees. A winding core for winding a film having a stepped portion extending in the longitudinal direction as a winding starting point on the outer peripheral surface,
In a cross section perpendicular to the longitudinal direction of the winding core, a rising start point P ₁ of the step portion, and the end point P ₂ of the step portion which is farther from the shaft center P ₀ of the core than the starting point P ₁ when defining the with origin P ₁ the end point P ₂ to the outer peripheral line S _1-2 of the winding core forms from is formed by straight line segments, the peripheral line S _1-2 is, the stepped portion A winding core characterized by being inclined with respect to a line segment LS _0-1 connecting the axial center P ₀ of the main winding core and the starting point P ₁ so as to be gentle. In a cross section perpendicular to the longitudinal direction of the main winding core, formed by a line segment LS _0-1 connecting the axis center P ₀ and the starting point P ₁ , the line segment LS _0-1 and the outer peripheral line S _1-2. when defined as the angle theta _B that is, a, the angle theta _B is winding core according to claim 6 which is 10 to 80 degrees. In a cross section perpendicular to the longitudinal direction of the core, a line segment LS _0-1 connecting the axis center P ₀ and the start point P ₁ and a line segment LS _0- connecting the axis center P ₀ and the end point P ₂ are used. ₂ and the angle θ _1-2 formed by the line segment LS _0-1 and the line segment LS _0-2 , the angle θ _1-2 is 0.05 to 3.0 degrees. The core according to claim 6 or 7.   The main core is composed of a main body portion made of a hard thermoplastic resin having a Rockwell R scale of 80 to 130, and a step portion made of a soft thermoplastic resin having a Shore A hardness of 30 to 95 and joined to the main body portion. A winding core according to any one of claims 1 to 8. A winding core for winding a film, having a stepped portion at a right angle extending in the longitudinal direction as a winding starting point on the outer peripheral surface,
The main core is composed of a main body portion made of a hard thermoplastic resin having a Rockwell R scale of 80 to 130, and a step portion made of a soft thermoplastic resin having a Shore A hardness of 30 to 95 and joined to the main body portion. And a winding core characterized by comprising:   A film winding body comprising: the core according to any one of claims 1 to 10; and a film wound around the core.   The film winding body according to claim 11, wherein the film is a display member forming film.   The film wound body according to claim 12, wherein the display member forming film has a support film layer and an inorganic particle-containing resin layer.   The film wound body according to claim 13, wherein the display member forming film has a resist layer between the support film layer and the inorganic particle-containing resin layer.

Images