JP2004250213A - Method for laminating roll film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for laminating a roll film for surely laminating the roll film without generating any bubbles. <P>SOLUTION: A laminating machine 1 draws out a linear polarization separating sheet 12 and a linear polarization sheet 11 respectively from a linear polarization separating film original roll 2 and a linear polarization film original roll 3, and laminates them with laminating rollers 7 after respectively separating separators 16, 18. As laminated surfaces are the outside faces of the respective rolls, once they are brought into contact with each other at one portion, the other portion is in a regular curling state to be separated from the laminated surfaces and lamination can be surely carried out without generating the bubbles. For the linear polarization separating sheet 12, the linear polarization separating film original roll 2 is rolled so as to have a protective film 15 on the opposite side of the laminated surface inside. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for laminating a roll film for laminating a roll film supplied as a roll-shaped raw material to another film or the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, film products having various optical characteristics such as a polarizing plate have been used for a display device such as a liquid crystal display device (LCD). In a transmissive liquid crystal display device, a linearly polarized light separating plate is disposed between a backlight and a polarizing plate of a liquid crystal display cell to improve display luminance. The display brightness can be improved by transmitting a linearly polarized light component whose vibration plane coincides with the transmission axis direction of the linearly polarized light separating plate and once reflecting a linearly polarized light component having a vibration plane close to the reflection axis direction. Such a linearly polarized light separating plate is also called a reflective polarizing film, a non-absorbing polarizing film, a brightness enhancement film, or the like, and for example, a film having a multilayer structure is known (for example, see Patent Document 1). DBM (Dual Brightness Enhancement Film) is sold by 3M as a linearly polarized light separating plate having a multilayer structure. In order to improve the brightness of a liquid crystal display device, Nitto Denko Corporation
A brightness enhancement film called (Polarization Conversion Film) is also sold. Even in a self-luminous display device such as an electroluminescence (EL) display device, by disposing a linearly polarized light separating plate on the front side of the light emitting display unit, it is possible to reduce reflected light of light incident from the outside and make the display easier to see. (For example, see Patent Document 2).
[0003]
The linearly polarized light separating plate is supplied as a linearly polarized light separating film from a manufacturer in the form of a roll-shaped raw material. The linearly polarized light separating film is used through a plurality of steps of linearly pulling out from a roll, cutting into a predetermined shape, bonding with a polarizing plate and the like, and further combining with a display device.
[0004]
[Patent Document 1]
JP-T-5050637 [Patent Document 2]
JP 2001-67022 A [0005]
[Problems to be solved by the invention]
In laminating a film product such as a linearly polarized light separating plate as described above, it is important to uniformly bond so as not to generate bubbles, wrinkles, or overall warpage.
If air bubbles or wrinkles are generated at the bonded portion, the transmitted light is scattered and optical performance is reduced. If a large warp occurs, it cannot be used as a flat optical component.
[0006]
The lamination of the linearly polarized light separating plate and the like is performed in a state where the adhesive or the like is applied. Therefore, for example, when a plurality of locations come into contact at the same time, the film product between the contact points becomes slack, and bubbles and wrinkles are generated. Since the bonding strength of the adhesive is large, it is difficult to return to an appropriate state once improper bonding is performed. A linearly polarized light separating plate or the like is an expensive material, and a decrease in yield leads to an increase in manufacturing cost.
[0007]
An object of the present invention is to provide a method for laminating a roll film, which can surely laminate the roll film without generating bubbles or the like.
[0008]
[Means for Solving the Problems]
The present invention is a method for laminating a roll film supplied by a roll-shaped material,
This is a method for laminating a roll film, wherein a roll-shaped raw material is wound so that the lamination surface side is on the outside.
[0009]
According to the present invention, a roll film supplied as a roll-shaped raw material is easily curled to the inner surface side of the original roll due to curl. Since the web is wound so that the bonding surface side is outside the roll, it tends to be warped outward with respect to the bonding surface during bonding and to be in a state of contact at only one location. If the bonding is advanced from the contacting part, sound bonding can be performed without bubbles or the like mixed.
[0010]
Further, the present invention is characterized in that the roll film is bonded to another film.
[0011]
According to the present invention, a roll film is pasted to another film, and in a pasting step for producing a film product having a plurality of functions, air bubbles and the like do not enter a joint portion, and good pasting is performed. be able to.
[0012]
In the present invention, the roll film is a linearly polarized light separating film,
The other film is a linear polarizing film,
The linearly polarized light separating film is used as an optical film constituting a part of the display device in a form after being bonded to the linearly polarized light film, and has a protective film which is finally peeled off and removed after the production of the display device. And
The roll-shaped raw material is characterized in that it is wound so that the protective film side faces inside.
[0013]
According to the present invention, a linearly polarized light film is bonded to a linearly polarized light separation film supplied as a roll-shaped raw material, and is used as an optical film constituting a part of a display device. In the linearly polarized light separating film, a protective film is bonded to an outer surface side opposite to a surface to be bonded to the linearly polarized light film so as not to be damaged in a manufacturing process. If this protective film side is wound so as to be on the inside of the roll-shaped material, the bonding surface will be on the outside of the roll, and the bonding can be performed with an appropriate warp.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1A shows a schematic configuration of a laminating machine that executes a method of laminating a roll film according to an embodiment of the present invention, and FIG. 1B shows a cross-sectional configuration of a laminating sheet that performs lamination. ). The laminating machine 1 can be mounted with the linearly polarized light separating film raw roll 2 and the linearly polarized film raw material roll 3, respectively, and can pull out and bond the film. The linearly polarized light separating film pulled out from the linearly polarized light separating film roll 2 is wound with a separator so as not to be damaged. Is cut to a predetermined length by a cutting device. On the cut linearly polarized light separating sheet, the linearly polarized light sheet is pulled out from the raw linearly polarized film roll 3 and separated by the bonding roll 7 so that the separator is separated by the separator winding mechanism 6. When lamination of a predetermined length is performed, the lamination sheet 10 is obtained by cutting with the cutting mechanism 8.
[0015]
The bonding sheet 10 is formed by bonding a linearly polarizing sheet 11 and a linearly polarizing separation sheet 12 as shown in FIG. The linearly polarizing sheet 11 has pressure-sensitive adhesive layers 13 and 14 on both surfaces, respectively, and one of the pressure-sensitive adhesive layers 13 is bonded to the linearly polarized light separating sheet 12. A protective film 15 is bonded to the surface of the linearly polarized light separating sheet 12 facing the bonding surface. A separator 16 is joined to the bonding surface side. The separator 17 is joined to the surface of the protective film 15. Separators 18 and 19 are respectively bonded to the surface side of the pressure-sensitive adhesive layers 13 and 14 of the linear polarizing sheet 11.
[0016]
In the laminating machine 1 shown in FIG. 1A, prior to lamination, the separators 16 and 18 on the lamination surface side are rolled up and removed by the separator winding mechanisms 4 and 6. As a result, the surface of the linearly polarized light separating sheet 12 and the surface of the pressure-sensitive adhesive layer 13 are exposed, and a state in which lamination is possible. Protect the surface of the linearly polarized light separating sheet 12 with the protective film 15 adhered to the surface of the linearly polarized light separating sheet 12 on the side where the bonding with the linearly polarizing sheet 11 is not performed via the pressure-sensitive adhesive layer 13. are doing. Although the separator 17 is also joined to the surface of the protective film 15, the separator 17 is peeled off before shipping as the bonded sheet 10. The pressure-sensitive adhesive layer 14 on the front surface side of the linearly polarized light separating sheet 11 opposite to the bonding surface is used when the bonding sheet 10 is bonded to a liquid crystal display cell or the like.
[0017]
FIG. 2 shows a cross-sectional configuration of a linearly polarized light separating film 20 supplied in the form of the raw linearly polarized light separating film roll 2 of FIG. The linearly polarized light separating sheet 12 such as DBEF has a thickness of 100 to 200 μm as a whole, and is formed such that both sides of the linearly polarized light separating layer 21 are sandwiched between skin protective layers 22 and 23. As described in Patent Document 1, the linearly polarized light separating layer 21 is formed by alternately forming an optical layer made of a thin film of polyethylene naphthalate (PEN) and an optical layer made of a thin film of a copolymer of polyethylene naphthalate, for example. It is formed by laminating 100 layers. The skin protective layers 22 and 23 are made of polyethylene naphthalate. On the outer surface of one skin protective layer 23, a protective film 15 made of polyethylene terephthalate (PET) having a thickness of about several tens of micrometers is mounted. The bonding between the skin protection layer 23 and the protection film 15 is performed by an adhesive (not shown).
[0018]
Separators 16 and 17 made of polyethylene (PE) are mounted on the outer surfaces of the other skin protective layer 22 and protective film 15, respectively. The joining of the separators 16 and 17 is also performed by affinity. The separators 16 and 17 are thicker than the protective film 15 and have a thickness of several tens of μm. As described above, the separators 16 and 17 are peeled off before shipment as the bonded sheet 10. Usually, the surface of the separator 16 which is not on the side of the protective film 15 is marked or the like, so that it can be seen that the side on which the protective film 15 is not present.
[0019]
The linearly polarized light separating film 20 has a transmission axis direction and a reflection axis direction as optical anisotropy. When light enters, light that vibrates in the transmission axis direction is transmitted, and light that vibrates in the reflection axis direction is reflected. In the bonding sheet 10 shown in FIG. 1B, the transmission axis direction of the linear polarization sheet 11 and the transmission axis direction of the linear polarization separation sheet 12 are matched.
[0020]
FIG. 3 shows a cross-sectional configuration of a linearly polarizing film 30 supplied in the form of the raw linearly polarizing film roll 3 of FIG. The linear polarizing sheet 11 is formed with the polarizing layer 31 interposed between the protective layers 32 and 33. The polarizing layer 31 has a thickness of, for example, several tens of μm, and the protective layers 32 and 33 are thicker than the polarizing layer 31. The polarizing layer 31 is stretched while heating a film of polyvinyl alcohol (PVA) or the like, and is brought into contact with a solution such as iodine (I) to arrange iodine molecules and the like in the stretching direction to add a polarizing function. Such a polarizing layer 31 absorbs light oscillating in the stretching direction and transmits light oscillating in a direction perpendicular to the stretching direction. The protective layers 32 and 33 are made of, for example, triacetyl cellulose (TAC), and are bonded to both sides of the polarizing layer 31 with an adhesive (not shown). On the outer surfaces of the protective layers 32 and 33, for example, acrylic pressure-sensitive adhesive layers 13 and 14 having a thickness of several tens of μm are provided. On the outer surfaces of the pressure-sensitive adhesive layers 13 and 14, for example, polyethylene terephthalate is used. The separators 18 and 19 are provided with a thickness of several tens of μm, respectively.
[0021]
When laminating with the laminating roll 7 of FIG. 1A, the separator 18 is automatically peeled off, and the pressure-sensitive adhesive layer 13 is separated from the linearly polarized light separating film 20 by the surface of the skin protective layer 22 where the separator 16 is peeled off. And is attached.
[0022]
FIG. 4 shows a cross-sectional configuration of a bonded product 40 manufactured by bonding the linearly polarized light separating film 20 of FIG. 2 and the linearly polarized light film 30 of FIG. The linearly polarized light separating layer 21 of the linearly polarized light separating film 20 has a property of easily transmitting light having a vibration plane in the transmission axis direction and reflecting light having a vibration plane in the reflection axis direction as optical anisotropy.
The polarizing layer 31 of the linear polarizing film 30 has a property of easily transmitting light having a vibration plane in the transmission axis direction as optical anisotropy and easily absorbing light having a vibration plane in the absorption axis direction. The bonded product 40 is bonded so that the direction of the transmission axis of the linearly polarized light separating layer 21 and the direction of the transmission axis of the polarizing layer 31 match.
[0023]
The bonded product 40 is shipped to a liquid crystal display device manufacturer as an intermediate product. The manufacturer of the liquid crystal display device peels off the separator 19 and attaches it to the glass substrate of the liquid crystal display cell with the adhesive layer 14. Finally, the protective film 15 is also peeled off.
[0024]
FIG. 5 shows the laminating machine 1 of FIG. 1 (a) in which the linearly polarized light separating film 20 drawn from the raw linearly polarized film roll 2 and the linearly polarized light film 30 drawn from the linearly polarized film raw roll 3 are bonded. The following shows the relationship between the directions. In the linearly polarized light separating film 20, the longitudinal direction is the transmission axis direction 20a, and the width direction is the reflection axis direction 20b. In the linear polarizing film 30, the width direction is the transmission axis direction 30a, and the longitudinal direction is the absorption axis direction 30b. Since both the transmission axis directions 20a and 30a are bonded together, the axis direction of the raw linearly polarized light separating film roll 2 and the axial direction of the linearly polarized light raw film roll 3 are orthogonal to each other.
[0025]
FIG. 6A shows the state of curl as warpage generated on the bonding surface due to the curl of the roll when the roll films as shown in FIG. 5 or at least one of them is a roll film. When the warpage from the surface to be bonded is represented by a curl value H, there are two types of curl: a normal curl in which the end is away from the bonding surface with respect to the center, and a reverse curl in which the end is closer to the bonding surface than the center. A condition can occur. As shown in (b), a reverse curl and a normal curl were prepared and bonded, and the results were compared. As a result, bubbles were mixed in the reverse curl, whereas no bubbles were mixed in the normal curl. It can be seen that proper bonding is performed. In order to bond the linearly polarized light separating sheet 12 in the state of normal curl by the bonding machine 1 of FIG. 1A, as shown in FIG. 1C, the protection sheet 15 on the side opposite to the bonding surface is removed. When the linearly polarized light separating film raw roll 2 is wound, it may be wound inward. Although the configuration in the thickness direction of the linear polarizing film 30 shown in FIG. 3 is symmetric, when the bonding is performed as shown in FIG. Surface.
[0026]
That is, in the present embodiment, the lamination of the roll film supplied by the roll-shaped raw material is performed by winding the roll-shaped raw material such that the bonding surface side is on the outside. A roll film supplied in the form of a roll is likely to curl toward the inner surface of the original roll due to curl. Since the material roll is wound so that the bonding surface side is outside the roll, it warps outward with respect to the bonding surface during bonding and forms a regular curl as shown in FIG. It is easy to be in a state to do. If bonding is advanced from the contacting portion, sound bonding can be performed without air bubbles and the like mixed.
[0027]
In particular, the linearly polarized light separating film 20 is difficult to manufacture and is relatively expensive, and it is necessary to improve the yield of bonding with the linearly polarized light film 30. Only by wrapping the protective film 15 side inward, good bonding in a normal curl state can be performed.
[0028]
【The invention's effect】
As described above, according to the present invention, the raw film is wound so that the bonding surface side of the roll film is on the outside of the roll. It is possible to perform sound bonding in a state where air bubbles and the like are not mixed.
[0029]
Further, according to the present invention, when the roll film is bonded to another film, good bonding can be performed without bubbles or the like entering the joint.
[0030]
Further, according to the present invention, when the linearly polarizing film is bonded to the linearly polarized light separating film supplied in the form of a roll, a protective film that protects the linearly polarized light separating film from being damaged or the like is a linearly polarized light. Since it is bonded to the outer surface side opposite to the lamination surface with the film, if the protective film side is wound inside the roll-shaped raw material, the curl is effectively used, and appropriate warpage Can be bonded in a state where the sheet is held.
[Brief description of the drawings]
FIG. 1 is a simplified side view showing a schematic configuration of a laminating machine for executing a method for laminating a roll film according to an embodiment of the present invention, and a cross-sectional view of a laminating sheet for laminating. is there.
FIG. 2 is a cross-sectional view of the linearly polarized light separating film 20 supplied in the form of the raw linearly polarized light separating film roll 2 of FIG.
FIG. 3 is a cross-sectional view of a linear polarizing film 30 supplied in the form of a raw linear roll 3 of FIG.
4 is a cross-sectional view of a bonded product 40 manufactured by bonding the linearly polarized light separating film 20 of FIG. 2 and the linearly polarized light film 30 of FIG.
FIG. 5 is a diagram illustrating a direction in which the linear polarizing separation film 20 drawn from the raw linear roll 2 and the linear polarizing film 30 drawn from the raw linear roll 3 are bonded by the bonding machine 1 of FIG. FIG. 4 is a simplified perspective view showing the relationship of FIG.
FIG. 6 is a cross-sectional view showing a state of curling of the linearly polarized light separating sheet 12 when laminating with the laminating machine 1 of FIG. 1, a chart showing test results of laminating states according to curl directions, and a normal curl. It is a perspective view which shows the form of the raw material roll 2 of a linearly polarized light separation film to obtain.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 laminating machine 2 raw roll of linearly polarized light separating film 3 raw roll of linearly polarized film 4, 6 separator winding mechanism 7 bonding roll 10 bonding sheet 11 linearly polarizing sheet 12 linearly polarizing separation sheet 13, 14 adhesive layer 15 Protective films 16, 17, 18, 19 Separator 20 Linearly polarized light separating film 21 Linearly polarized light separating layer 30 Linearly polarizing film 31 Polarizing layer

Claims (3)

The lamination of the roll film supplied by the roll material is
A method for laminating a roll film, wherein a roll-shaped raw material is wound so that the lamination surface side is on the outside. The method for laminating a roll film according to claim 1, wherein the roll film is laminated with another film. The roll film is a linearly polarized light separating film,
The other film is a linear polarizing film,
The linearly polarized light separating film is used as an optical film constituting a part of the display device in a form after being bonded to the linearly polarized light film, and has a protective film which is finally peeled off and removed after the production of the display device. And
3. The method of laminating a roll film according to claim 2, wherein the roll-shaped raw material is wound so that the protective film side faces inside.

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