JP2021184086A - Manufacturing method for optical laminate and manufacturing apparatus for optical laminate - Google Patents

Abstract

To provide a manufacturing method for an optical laminate and a manufacturing apparatus for an optical laminate, by which the temperature unevenness in a width direction on a surface or a roll can be reduced and the problem of the quality of a bonding film can be reduced.SOLUTION: A manufacturing method for an optical laminate includes a bonding step of forming a bonding film from two different films through an adhesive of an energy line activation type, and an activating step of irradiating the bonding film with an energy line while bringing the bonding film into contact with the roll so as to activate the adhesive. A heat medium flow path for feeding a heat medium in the roll is provided. By heat medium circulating means, the temperature of the surface of the roll is adjusted. The heat medium flow path includes a main path extending in accordance with the entire region of an outer peripheral surface part of a roll main body part along a rotation shaft center, an introduction path for introducing the heat medium to the main path, a first discharge path connecting to the main path and discharging the heat medium flowing in the main path, and a second discharge path. The activating step includes an operation of feeding the heat medium into the heat medium flow path while the outer peripheral surface part rotates the roll main body part extending in a cylindrical shape.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing an optical laminate and an apparatus for manufacturing an optical laminate.

In the manufacture of an optical laminate such as a polarizing plate, the optical films of each layer constituting the optical laminate are bonded with an energy ray-active adhesive, and then the activation treatment is performed while transporting the obtained bonded film. It is done. The activation treatment is performed by irradiating the bonded film passing on the roll with energy rays. The irradiation of the energy rays is usually performed while cooling the bonded film on a cooled roll so as not to cause problems in the quality of the bonded film such as deformation of the bonded film and uneven curing.
Conventionally, as a method for cooling a roll, for example, as shown in Japanese Patent Application Laid-Open No. 2019-3210 (Patent Document 1), it is known to flow a heat medium in the roll.

Japanese Unexamined Patent Publication No. 2019-3210

However, when the heat medium is passed through the roll as in the conventional case, there is a possibility that temperature unevenness may occur in the width direction of the surface of the roll. Further, the temperature unevenness in the width direction of the surface of the roll may make the reaction rate of the adhesive non-uniform in the width direction of the bonded film, and may cause a problem in the quality of the bonded film.

Therefore, the present disclosure is to provide a method for manufacturing an optical laminate and an apparatus for manufacturing an optical laminate in which the temperature unevenness in the width direction of the surface of the roll is reduced and the problem of the quality of the laminated film is reduced.

In response to the above problems, the inventors of the present application have found that the occurrence of temperature unevenness is caused by the gas accompanying the circulation of the heat medium, and have completed the invention of the present application.
The method for manufacturing an optical laminate of the present invention is:
A method for manufacturing an optical laminate having at least one layer made of an optical film.
The bonding process of forming a bonding film by bonding two films that are different from each other via an energy ray-active adhesive, and
It is provided with an activation treatment step of irradiating the bonded film with energy rays on the roll while bringing the bonded film into contact with the roll to activate the adhesive.
Inside the roll, a heat medium flow path through which a heat medium flows is provided, and the roll includes a roll main body portion in which the roll center line coincides with the rotation axis and the outer peripheral surface portion extends in a cylindrical shape. The temperature of the surface of the roll is adjusted by the heat medium circulation means for circulating the heat medium in the flow path.
The heat medium flow path extends along the rotation axis so as to correspond to the entire outer peripheral surface portion of the roll main body portion, and extends on the rotation axis and communicates with the main passage to the main passage. An introduction passage for introducing the heat medium into the passage, a first discharge passage extending on the rotation axis and communicating with the main passage to discharge the heat medium flowing into the main passage, and one end of the main passage. It is provided with a second discharge passage that communicates with the main passage on the downstream side and at a position close to the outer peripheral surface portion, while the other end communicates with the first discharge passage.
The activation treatment step includes an operation of flowing a heat medium into the heat medium flow path while rotating the roll main body portion.

According to the above aspect, since the activation treatment step includes an operation of flowing a heat medium into the heat medium flow path while rotating the roll main body, the roll is made to discharge the gas in the main passage from the second discharge passage. A heat medium can be passed through the main body. This reduces the temperature unevenness in the width direction of the surface of the roll caused by the gas in the roll, makes the reaction rate of the adhesive substantially uniform in the width direction of the bonded film, and reduces the problem of the quality of the bonded film. can do.

Further, the method for manufacturing the optical laminate of the present invention is as follows.
A method for manufacturing an optical laminate having at least one layer made of an optical film.
The bonding process of forming a bonding film by bonding two films that are different from each other via an energy ray-active adhesive, and
It is provided with an activation treatment step of irradiating the bonded film with energy rays on the roll while bringing the bonded film into contact with the roll to activate the adhesive.
Inside the roll, a heat medium flow path through which a heat medium flows is provided, and the roll includes a roll main body portion in which the roll center line coincides with the rotation axis and the outer peripheral surface portion extends in a cylindrical shape. The temperature of the surface of the roll is adjusted by the heat medium circulation means for circulating the heat medium in the flow path.
The heat medium flow path includes a main passage extending along the rotation axis so as to correspond to the entire outer peripheral surface portion of the roll main body portion, and a discharge passage for discharging the heat medium flowing through the main passage. Ori,
The activation treatment step includes an operation of flowing a heat medium into the heat medium flow path while rotating the roll main body portion, and the volume of the heat medium flowing in the main passage is the total volume of the main passage. It is maintained at 90% or more and 100% or less.

According to the above aspect, the activation treatment step includes an operation of flowing a heat medium into the heat medium flow path while rotating the roll main body portion, and the volume of the heat medium flowing in the main passage is the total volume of the main passage. Since it is maintained at 90% or more and 100% or less, the heat medium can be flowed into the roll main body while discharging the gas in the main passage from the discharge passage. This reduces the temperature unevenness in the width direction of the surface of the roll caused by the gas in the roll, makes the reaction rate of the adhesive substantially uniform in the width direction of the bonded film, and reduces the problem of the quality of the bonded film. can do.

Preferably, in one embodiment of the method for manufacturing an optical laminate, the activation treatment step is performed in a state where the temperature distribution in the width direction of the surface of the roll main body portion is maintained at 3.5 ° C. or lower.

According to the above embodiment, since the activation treatment step is performed in a state where the temperature distribution in the width direction of the surface of the roll main body is maintained at 3.5 ° C. or lower, the temperature unevenness in the width direction of the surface of the roll is further reduced. Therefore, the problem of the quality of the bonded film can be further reduced.

One embodiment of the method for manufacturing an optical laminate includes a step of irradiating an activated film 33 with energy rays.

According to the above embodiment, further, since the step of irradiating the bonded film that has undergone the activation treatment with energy rays is included, the activation treatment of the adhesive can be performed more reliably.

Further, the apparatus for manufacturing an optical laminate, which is one aspect of the present disclosure, is
An apparatus for manufacturing an optical laminate having at least one layer made of an optical film.
A bonding device that forms a bonding film by bonding two films that are different from each other via an energy ray-active adhesive.
The roll that comes into contact with the bonding film and
A device for activating the adhesive by irradiating the bonded film with energy rays on the roll is provided.
Inside the roll, a heat medium flow path through which a heat medium flows is provided, and the roll includes a roll main body portion in which the roll center line coincides with the rotation axis and the outer peripheral surface portion extends in a cylindrical shape. The temperature of the surface of the roll is adjusted by the heat medium circulation means for circulating the heat medium in the flow path.
The heat medium flow path extends along the rotation axis so as to correspond to the entire outer peripheral surface portion of the roll main body portion, and extends on the rotation axis and communicates with the main passage to the main passage. An introduction passage for introducing the heat medium into the passage, a first discharge passage extending on the rotation axis and communicating with the main passage to discharge the heat medium flowing into the main passage, and one end of the main passage. It is provided with a second discharge passage that communicates with the main passage on the downstream side and at a position close to the outer peripheral surface portion, while the other end communicates with the first discharge passage.

According to the above aspect, since the heat medium flow path of the roll has a second discharge passage communicating with the main passage, the heat medium is flowed into the roll main body while discharging the gas in the main passage from the second discharge passage. Can be done. This reduces the temperature unevenness in the width direction of the surface of the roll caused by the gas in the roll, makes the reaction rate of the adhesive substantially uniform in the width direction of the bonded film, and reduces the problem of the quality of the bonded film. can do.

Preferably, in one embodiment of the optical laminate manufacturing apparatus, when the adhesive is activated by the activation treatment apparatus, the temperature distribution in the width direction of the surface of the roll main body portion is 3.5 ° C. or lower. It also has a control device that controls the state maintained at.

According to the above-described embodiment, when the adhesive is activated by the activation treatment device, the temperature distribution in the width direction of the surface of the roll main body is controlled to further increase the temperature unevenness in the width direction of the surface of the roll. It can be reduced to further reduce the quality problem of the bonded film.

Preferably, in one embodiment of the optical laminate manufacturing apparatus,
The roll main body has an outer pipe and an inner pipe, and has an outer pipe and an inner pipe.
The space between the outer pipe and the inner pipe constitutes a part of the heat medium flow path.

According to the above embodiment, since the space between the outer pipe and the inner pipe forms a part of the heat medium flow path, the heat medium can flow only in a part of the space inside the outer pipe. Therefore, the flow velocity can be increased with a smaller amount of heat medium as compared with a single tube roll having the same diameter.

Preferably, in one embodiment of the optical laminate manufacturing apparatus, two or more of the second discharge passages are provided.

According to the above embodiment, since two or more second discharge passages are provided, gas can be efficiently discharged.

Preferably, in one embodiment of the optical laminate manufacturing apparatus, the second discharge passages are provided at equal intervals around the rotation axis.

According to the above embodiment, since each second discharge passage passes through the gas pool at the upper part of the roll at short intervals during the rotation operation of the roll, the gas collected at the upper part of the main passage per rotation of the roll. The discharge time of the gas is increased, and the main passage can be efficiently filled with the heat medium.

According to the method for manufacturing an optical laminate and the apparatus for manufacturing an optical laminate, which is one aspect of the present disclosure, it is possible to reduce the temperature unevenness in the width direction of the surface of the roll and reduce the problem of the quality of the bonded film.

It is a schematic diagram which shows one Embodiment of the manufacturing apparatus of an optical laminate. FIG. 3 is a schematic cross-sectional view of an embodiment of a roll. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. It is an enlarged view of Part III of FIG. FIG. 3 is a schematic cross-sectional view showing another embodiment of the roll. 5A is a cross-sectional view taken along the line AA of FIG. 5A.

Hereinafter, a method for manufacturing an optical laminate and an apparatus for manufacturing an optical laminate, which is one aspect of the present disclosure, will be described in detail with reference to the illustrated embodiments. The drawings may include some schematic ones and may not reflect the actual dimensions and ratios.

(Embodiment)
(Manufacturing equipment for optical laminates)
FIG. 1 is a schematic view showing an embodiment of an apparatus for manufacturing an optical laminate. As shown in FIG. 1, the optical laminate manufacturing apparatus 15 is attached to a bonding device 16 for bonding a first film 31 and a second film 32, which are different from each other, to form a bonding film 33, and a bonding film 33. A roll 2 in contact with the roll 2, an activation processing device 13 for irradiating the bonded film 33 with energy rays to form an optical laminate 34, and a control device 17 for controlling the roll 2 are provided.

In this embodiment, the first film 31 is an optical film such as a polarizing film, the second film 32 is a transparent film, and the optical laminate 34 is a polarizing plate. These films are conveyed in the direction indicated by the arrow in FIG.

The optical film is a resin film exhibiting optical characteristics such as a polarizing film and a retardation film. The polarizing film is formed, for example, by dyeing a uniaxially stretched polyvinyl alcohol film with iodine or a dichroic dye and then treating it with boric acid.
Examples of the transparent film include thermoplastic resins such as an amorphous polyolefin resin film, a polyester resin film, an acrylic resin film, a polycarbonate resin film, a polysulfone resin film, and an alicyclic polyimide resin film. As the transparent film, a resin film having a low moisture permeability is preferable. Further, examples of the transparent film include a cellulose acetate-based resin film such as a triacetyl cellulose film and a diacetyl cellulose film.

The optical film may be a single layer or a laminated body. The type of the optical film is not particularly limited as long as it is a film exhibiting optical characteristics. The obtained optical laminate may have a film that does not exhibit optical characteristics, and if it exhibits optical characteristics, for example, an optical film such as a retardation film, a protective film, or the above-mentioned polarizing film, or an optical film such as the above-mentioned polarizing film, or It may be an optical laminate in which these films or thermoplastic resins are laminated. That is, the optical laminate may have at least one layer made of an optical film.

The bonding device 16 is a first bonding device 11 in which an adhesive coating device 11 that applies an adhesive to one side of the first film 31 and a first film 31 and a second film 32 are laminated and bonded via an adhesive. It has a roll 21 and a second bonding roll 22. The adhesive is an energy ray active type adhesive.

As the adhesive, for example, an epoxy resin containing no aromatic ring in the molecule is used from the viewpoint of weather resistance, refractive index, cationic polymerization, and the like. As the epoxy resin, for example, a hydrogenated epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin and the like are used. The epoxy resin contains a polymerization initiator, for example, a photocationic polymerization initiator for polymerization by irradiation with active energy rays, a thermal cationic polymerization initiator for polymerization by heating, and other additives (sensitizer, etc.). Is added.

The roll 2 is rotationally driven so that the center line of the roll 2 coincides with the center of rotation, and the laminated film 33 is conveyed while being in contact with the surface of the roll 2. The roll 2 comes into contact with the bonding film 33. That is, when the laminating film 33 is irradiated with energy rays from the activation processing device 13, the roll 2 comes into contact with the laminating film 33 to make it difficult for heat to be applied to the laminating film 33. The roll 2 has a heat medium flow path inside which the heat medium flows, and the heat medium flows through the heat medium flow path to cool the bonded film 33. The heat medium is, for example, a refrigerant such as water.

The roll 2 includes a roll main body portion whose outer peripheral surface portion extends in a cylindrical shape. The temperature of the surface of the roll 2 is adjusted by the heat medium circulation means for circulating the heat medium in the heat medium flow path. The heat medium circulation means is composed of, for example, a heat medium circulation unit including a circulation pump and the like, and is controlled by the control device 17.

The heat medium flow path extends along the rotation axis so as to correspond to the entire outer peripheral surface of the roll body, and extends on the rotation axis and communicates with the main passage to introduce the heat medium into the main passage. An introduction passage, a first discharge passage that extends on the axis of rotation and communicates with the main passage to discharge the heat medium that has flowed into the main passage, and one end is on the downstream side of the main passage and is close to the outer peripheral surface portion. It is provided with a second discharge passage that communicates with the main passage at the above-mentioned position, while the other end communicates with the first discharge passage.

Since the heat medium flow path of the roll 2 has a second discharge passage communicating with the main passage, the heat medium can flow into the roll main body while discharging the gas in the main passage from the second discharge passage. The gas is, for example, air. The second discharge passage may discharge not only the gas but also the heat medium. Therefore, the temperature unevenness in the width direction of the surface of the roll 2 caused by the gas in the roll 2 is reduced, the reaction rate of the adhesive is made substantially uniform in the width direction of the bonding film 33, and the quality of the bonding film 33 is improved. The problem can be reduced.

Further, since the second discharge passage communicates with the main passage located close to the outer peripheral surface portion, when the rotation axis of the roll 2 is arranged horizontally and used, the gas accumulated on the outer peripheral surface portion side of the main passage is discharged. It can be effectively discharged from the second discharge passage.
Further, since the second discharge passage communicates with the downstream side of the main passage, the gas can be efficiently discharged according to the flow of the heat medium.

The roll main body may be composed of, for example, a single tube of the outer tube, and at this time, the space inside the outer tube constitutes a part (main passage) of the heat medium flow path. Further, the roll main body may be composed of, for example, a double pipe of an outer pipe and an inner pipe, and at this time, the space between the outer pipe and the inner pipe is a part (main passage) of the heat medium flow path. To configure. The space between the outer pipe and the inner pipe is formed in an annular shape when viewed from the direction of the rotation axis of the roll 2.

The activation processing device 13 is arranged facing the roll 2. The activation treatment device 13 irradiates the bonded film 33 with energy rays on the roll 2 to activate the adhesive. That is, the activation treatment device 13 polymerizes and cures the adhesive by irradiating with energy rays. In this way, the optical laminate 34 formed by the activation treatment of the activation treatment device 13 is wound by the take-up roll 20. The energy rays are usually applied not only on the roll 2 but also around the roll 2.
The activation treatment apparatus 13 has, for example, a light emission distribution having a wavelength of 400 nm or less, and uses a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, or the like. ..

The control device 17 preferably has a temperature distribution (maximum temperature difference) in the width direction of the surface of the roll body portion of 3.5 ° C. or less, more preferably when the adhesive is activated by the activation treatment device 13. Control to maintain the temperature below 2 ° C. That is, preferably, the control device 17 sets the difference between the maximum temperature in the width direction of the surface of the roll body portion and the minimum temperature in the width direction of the surface of the roll body portion to 3.5 ° C. or less. According to this, the temperature unevenness in the width direction of the surface of the roll 2 can be further reduced, and the quality problem of the bonded film 33 can be further reduced.
Specifically, the control device 17 is composed of a central processing unit. The control device 17 controls, for example, the heat medium circulation means to adjust the flow velocity of the heat medium in the roll 2, the flow rate of the heat medium in the roll 2, the amount of the heat medium in the roll 2, and the like. The temperature distribution in the width direction of the surface of the roll 2 is maintained at 3.5 ° C. or lower.

Preferably, the roll body has an outer tube and an inner tube, and the space between the outer tube and the inner tube constitutes a part of the heat medium flow path. According to this, since the heat medium can flow only in a part of the space inside the outer tube, the flow velocity can be increased with a smaller amount of the heat medium as compared with the roll 2 of the single tube having the same diameter.

Preferably, two or more second discharge passages are provided. According to this, the number of the second discharge passages is increased, and the gas can be efficiently discharged. Preferably, the second discharge passages are provided at equal intervals around the center of rotation. According to this, each second discharge passage passes through the gas pool at the upper part of the roll at short intervals during the rotation operation of the roll 2, so that the gas collected at the upper part of the main passage per rotation of the roll 2 The discharge time of the gas is increased, and the main passage can be efficiently filled with the heat medium.

The manufacturing apparatus of the present disclosure is not limited to the above-described embodiment, and the design can be changed without departing from the gist of the present disclosure. The manufacturing apparatus may have two or more activation processing apparatus and rolls, respectively. In the manufacturing apparatus, the plurality of activation processing apparatus may be provided so as to face one roll.

(Manufacturing method of optical laminate)
Next, an embodiment of a method for manufacturing an optical laminate will be described with reference to FIG. 1.
First, the first film 31 and the second film 32 are bonded together via an energy ray-active adhesive to form a bonded film 33. This is called the bonding process. Then, while the bonding film 33 is in contact with the roll 2, the bonding film 33 is irradiated with energy rays on the roll 2 to activate the adhesive. This is called an activation treatment step.

Here, inside the roll 2, a heat medium flow path through which the heat medium flows is provided. The roll 2 includes a roll main body portion whose outer peripheral surface portion extends in a cylindrical shape while the roll center line coincides with the rotation axis. The temperature of the surface of the roll 2 is adjusted by the heat medium circulation means for circulating the heat medium in the heat medium flow path.

The heat medium flow path extends along the rotation axis so as to correspond to the entire outer peripheral surface of the roll body, and extends on the rotation axis and communicates with the main passage to introduce the heat medium into the main passage. An introduction passage, a first discharge passage that extends on the axis of rotation and communicates with the main passage to discharge the heat medium that has flowed into the main passage, and one end is on the downstream side of the main passage and is close to the outer peripheral surface portion. It is provided with a second discharge passage that communicates with the main passage at the above-mentioned position, while the other end communicates with the first discharge passage.
The activation treatment step includes an operation of flowing a heat medium into the heat medium flow path while rotating the roll main body.

According to this, since the activation treatment step includes an operation of flowing a heat medium into the heat medium flow path while rotating the roll main body, the roll main body is discharged from the second discharge passage while discharging the gas in the main passage. A heat medium can be passed through the section. Therefore, the temperature unevenness in the width direction of the surface of the roll 2 caused by the gas in the roll 2 is further reduced, the reaction rate of the adhesive is made substantially uniform in the width direction of the bonded film 33, and the quality of the bonded film 33 is obtained. The problem can be reduced.

Preferably, in the activation treatment step, the volume of the heat medium flowing in the main passage is maintained at 90% or more and 100% or less, more preferably 95% or more and 100% or less with respect to the total volume of the main passage. According to this, the temperature unevenness in the width direction of the surface of the roll 2 can be further reduced, and the quality problem of the bonded film 33 can be further reduced.

Here, the amount of gas discharged in the main passage can be adjusted by appropriately adjusting the flow rate of the heat medium flowing in the heat medium flow path, the rotation speed of the roll body, the size of the cross-sectional area of each discharge passage, and the like. can. That is, the volume of the heat medium flowing in the main passage can be adjusted by discharging the gas in the main passage. The volume of the heat medium flowing in the main passage can be easily adjusted by the roll in the manufacturing apparatus of the present disclosure.

Preferably, the activation treatment step is performed in a state where the temperature distribution in the width direction of the surface of the roll main body portion is maintained at 3.5 ° C. or lower (more preferably 2 ° C. or lower). According to this, the temperature unevenness in the width direction of the surface of the roll 2 can be further reduced, and the quality problem of the bonded film 33 can be further reduced.

In the activation treatment step, when the bonded film 33 is irradiated with energy rays a plurality of times, the energy rays are usually irradiated by using a manufacturing apparatus provided with two or more activation treatment devices. The energy ray irradiation may be performed while passing one roll facing the two or more activation treatment devices, or having two or more rolls facing the one or more activation treatment devices. The bonding film may be passed through a plurality of rolls by using an apparatus.
The present embodiment further includes a step of irradiating the bonded film 33 obtained with the activation treatment with energy rays. According to this, the activation treatment of the adhesive can be performed more reliably.
In the present embodiment, the step of irradiating the bonded film 33 obtained with the activation treatment with energy rays is performed on a roll having a structure different from that of the roll in the activation treatment step. Different from ray irradiation.

The manufacturing method of the present disclosure is not limited to the above-described embodiment, and the design can be changed without departing from the gist of the present disclosure. For example, the manufacturing method of the present disclosure is not limited to being realized by the manufacturing apparatus 15 of FIG. 1, and may be realized by another different apparatus.

Further, in another embodiment of the method for manufacturing an optical laminate, a bonding step and an activation treatment step are provided, a heat medium flow path through which a heat medium flows is provided inside the roll, and the roll is centered on the roll. The roll body is provided with a roll body whose line coincides with the center of rotation and whose outer peripheral surface extends in a cylindrical shape, and the temperature of the surface of the roll is adjusted by the heat medium circulation means for circulating the heat medium in the heat medium flow path. The heat medium flow path includes a main passage extending along the rotation axis so as to correspond to the entire outer peripheral surface portion of the roll main body portion, and a discharge passage for discharging the heat medium flowing through the main passage. That is, the discharge passage is not limited to the first discharge passage and the second discharge passage, and for example, the second discharge passage may not be present. The activation treatment step includes an operation of flowing a heat medium into the heat medium flow path while rotating the roll main body portion. In the activation treatment step, the volume of the heat medium flowing in the main passage is maintained at 90% or more and 100% or less, preferably 95% or more and 100% or less of the total volume of the main passage.

According to this, the heat medium can flow into the roll main body while discharging the gas in the main passage from the discharge passage. Therefore, the temperature unevenness in the width direction of the surface of the roll caused by the gas in the roll is reduced, the reaction rate of the adhesive is made substantially uniform in the width direction of the bonded film, and the problem of the quality of the bonded film is reduced. be able to.

(Roll structure)
FIG. 2 is a schematic cross-sectional view of an example of an apparatus provided with a roll applicable to the manufacturing method of the present disclosure (hereinafter, the roll may be referred to as “roll apparatus 1”). As shown in FIG. 2, the roll device 1 is for adjusting the temperature of the bonded film W1 in contact with the continuously conveyed bonding film W1 (bonding film 33 of FIG. 1). The roll device 1 is included in the optical laminate manufacturing device 15.

The roll device 1 has a heat medium flow path 10 through which the heat medium H1 flows, and the above-mentioned roll 2 that can rotate around the rotation axis C1 and heat that circulates the heat medium H1 in the heat medium flow path 10. It is provided with a medium circulation unit 3 (the heat medium circulation means).

The roll 2 is formed of a metal material, and the roll center line coincides with the rotation axis C1 and the outer peripheral surface portion 4a extends in a cylindrical shape. Each shaft portion 5 is provided with a pair of shaft portions 5 whose axis center line coincides with the rotation axis C1 and a pair of rotary joints 6 for connecting each shaft portion 5 and the heat medium circulation unit 3. It is rotatably supported by the support frame 7 via the bearing B1.

The heat medium flow path 10 includes a main passage 10a formed inside the roll main body 4, and an introduction passage 10b that extends linearly on the rotation axis C1 of one of the shafts 5 and communicates with the main passage 10a. It is provided with a first discharge passage 10c that extends linearly on the rotation axis C1 of the other shaft portion 5 and communicates with the main passage 10a.

The main passage 10a has a circular cross-sectional shape and a shape extending along the rotation axis C1 so as to correspond to the entire outer peripheral surface portion 4a.
The introduction passage 10b has a circular cross section and is set to have a narrower cross-sectional area than the main passage 10a, so that the heat medium H1 discharged from the heat medium circulation unit 3 is introduced into the main passage 10a.
The first discharge passage 10c has a circular cross section and is set to have a narrower cross-sectional area than the main passage 10a, so that the heat medium H1 of the main passage 10a is discharged to the heat medium circulation unit 3. That is, the cross-sectional area of the first discharge passage 10c is narrower than the cross-sectional area of the portion extending along the rotation axis C1 in the main passage 10a so as to correspond to the entire outer peripheral surface portion 4a.
The heat medium circulation unit 3 circulates the heat medium H1 from one end side to the other end side of the roll 2, and the heat medium H1 circulates the inside of the roll 2 through the introduction passage 10b, the main passage 10a, and the first discharge passage 10c. It is designed to pass in the order of.

Inside the other end face portion 4b of the roll main body portion 4, a second discharge passage 10d extending in an L shape when viewed from the front is formed. As shown in FIGS. 2 to 4, the second discharge passage 10d communicates with the main passage 10a at a position where one end is on the downstream side of the main passage 10a in the roll main body 4 and is close to the outer peripheral surface portion 4a. The other end communicates with the upstream side of the first discharge passage 10c, and 12 places are formed at equal intervals around the rotation axis C1.

Next, the flow of the heat medium H1 inside the roll 2 when the roll device 1 is operated will be described in detail.
First, the heat medium circulation unit 3 in the roll device 1 is operated. Then, the heat medium H1 flows in order through the introduction passage 10b, the main passage 10a, and the first discharge passage 10c in the roll 2.

Next, the roll 2 is rotated to one side (arrow R1 in FIG. 3) around the rotation axis C1 and is brought into contact with the laminated film W1 which is continuously conveyed. At this time, the heat medium H1 flows inside the roll 2 in the order of the introduction passage 10b, the main passage 10a, and the first discharge passage 10c. Then, the heat medium H1 can be flowed into the roll main body 4 while discharging the gas in the main passage 10a from the second discharge passage 10d. It is preferable that the heat medium H1 circulates so as to be in constant contact with the entire back surface of the outer peripheral surface portion 4a of the roll main body portion 4. When the heat medium H1 circulates so as to be in constant contact with the entire back surface of the outer peripheral surface portion 4a, the outer peripheral surface portion 4a of the roll main body portion 4 is cooled without variation. It is possible to prevent variation from occurring.

Further, since the gas does not collect on the upper portion of the roll main body portion 4, the time required to cool the outer peripheral surface portion 4a to a desired temperature is shortened, and the bonded film W1 can be efficiently cooled.

Further, since the second discharge passages 10d are formed at two or more locations around the rotation axis C1 at equal intervals, each of the second discharge passages 10d shortens the gas pool on the upper part of the roll 2 during the rotation operation of the roll 2. It will pass at intervals. Therefore, the discharge time of the gas accumulated in the upper part of the main passage 10a per rotation of the roll 2 is increased, and the heat medium H1 can be efficiently filled in the main passage 10a without any gap.

Further, since each of the second discharge passages 10d is formed inside the end face portion 4b of the roll main body portion 4, the roll 2 is compared with the case where the structure having the second discharge passage 10d is attached to the outside of the roll main body portion 4. The outer shape of is smaller. Therefore, the entire roll 2 can be made compact, and the space around the roll 2 can be effectively used.

(Other structures of rolls)
FIG. 5A is a schematic cross-sectional view showing another embodiment of the roll applicable to the manufacturing method and manufacturing apparatus of the present disclosure. 5B is a sectional view taken along the line AA of FIG. 5A. This roll 50 is a double-tube roll, unlike the roll 2 of FIG. 2, which is a single tube. Hereinafter, only the portion different from the roll 2 will be described.

As shown in FIGS. 5A and 5B, the roll 50 has an outer pipe 51, an inner pipe 52, a first shaft portion 53, and a second shaft portion 54. The inner pipe 52 is arranged inside the outer pipe 51, and the outer pipe 51 and the inner pipe 52 form a roll main body portion. The first shaft portion 53 is provided at one end of the roll main body portion, and the second shaft portion 54 is provided at the other end of the roll main body portion.

The roll 50 has a heat medium flow path 55 through which a heat medium flows. The heat medium flow path 55 is provided in the main passage provided in the roll main body (outer pipe 51 and inner pipe 52), the introduction passage 55d provided in the first shaft portion 53, and the second shaft portion 54. It has a first discharge passage 55e.

The main passages are the first passage 55a having an annular cross section located between the outer pipe 51 and the inner pipe 52 when viewed from the rotation axis C1 direction of the roll 50, and the first passage radially extending from the rotation axis C1. It is composed of a plurality of second passages 55b communicating with one end side of the 55a and a plurality of third passages 55c extending radially from the rotation axis C1 and communicating with the other end side of the first passage 55a.

The first passage 55a extends along the rotation axis C1 so as to correspond to the entire outer peripheral surface portion 51a of the roll main body portion. The second passage 55b and the third passage 55c are each formed at equal intervals around the rotation axis C1. Each second passage 55b communicates the introduction passage 55d and the first passage 55a, and each third passage 55c communicates the first passage 55a and the first discharge passage 55e.
The first discharge passage 55e is set to have a narrower cross section than the first passage 55a. That is, the cross-sectional area of the first discharge passage 55e is narrower than the cross-sectional area of the portion extending along the rotation axis C1 in the main passage so as to correspond to the entire outer peripheral surface portion 51a.
Then, as shown by the dotted arrow in FIG. 5A, the heat medium passes through the second passage 55b, the first passage 55a, and the third passage 55c in order from the introduction passage 55d, and is discharged from the first discharge passage 55e. NS.

Around the second shaft portion 54, a plurality of second discharge passages 55f extending substantially radially when viewed from the rotation axis C1 direction are arranged around the rotation axis C1 at equal intervals. The second discharge passage 55f includes a pipe. The pipe is composed of, for example, a pipe tube made of a rubber material, but may be formed of a metal pipe or a resin pipe.
One end of the second discharge passage 55f communicates with the main passage (first passage 55a) located on the downstream side of the main passage and close to the outer peripheral surface portion 51a, and the other end of the second discharge passage 55f is the first. It communicates with the discharge passage 55e.
The movement of discharging the gas accumulated in the upper part of the main passage (first passage 55a) is different from that of the roll 2 in FIG. 2, except that the discharge path changes from the second discharge passage 10d to the second discharge passage 55f. Are the same, so detailed description will be omitted.

As described above, since the second discharge passage 55f is arranged outside the roll main body portion and the second shaft portion 54, the second discharge passage 55f is compared with the structure formed inside the end portion of the roll main body portion. The processing cost is low, and the roll 50 can be made at a low cost.

(Example)
Next, an embodiment will be described.

(1st film)
A 20 μm-thick PVA film (average polymerization degree of about 2400, saponification degree of 99.9 mol% or more) was uniaxially stretched about 6 times by dry stretching, and further uniaxially stretched to pure water at 40 ° C. while maintaining a tense state. Soaked for 40 seconds.

Next, this film was dyed by immersing it in a dyeing aqueous solution at 28 ° C. having a mass ratio of iodine / potassium iodide / water of 0.044 / 5.7 / 100 for 30 seconds. Next, the dyed film was crosslinked by immersing it in a 70 ° C. boric acid aqueous solution having a mass ratio of potassium iodide / boric acid / water of 11.0 / 6.2 / 100 for 120 seconds. ..

Subsequently, the crosslinked film was washed with pure water at 8 ° C. for 15 seconds, and then dried at 60 ° C. for 50 seconds and then at 75 ° C. for 20 seconds while being held at a tension of 300 N / m. In this way, a polarizing film having a thickness of 7 μm in which iodine was adsorbed and oriented on the PVA film was obtained.

As a protective film, a cycloolefin resin film (COP, ZF-14 manufactured by Nippon Zeon Corporation, 13 μm thick without UV absorption characteristics) was prepared. A water-based adhesive was injected between the obtained polarizing film and the cycloolefin-based resin film, and the films were bonded together with a nip roll. The obtained laminate was dried at 60 ° C. for 2 minutes while maintaining the tension at 430 N / m to obtain a first film comprising a polarizing element layer and a protective layer arranged on one side of the polarizing element layer. .. The thickness of the first film was 20 μm.

The water-based adhesive is 100 parts by mass of water, 3 parts by mass of carboxyl group-modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd .; Kuraray Poval (registered trademark) KL318), and a water-soluble polyamide epoxy resin (manufactured by Taoka Chemical Industry Co., Ltd .;). It was prepared by adding 1.5 parts by mass of Kuraray's resin (registered trademark) 650; an aqueous solution having a solid content concentration of 30%.

(2nd film)
As a transparent film, a film formed of a polyethylene terephthalate film having a thickness of 38 μm was prepared. The composition for the alignment layer was applied to one side of the transparent film so as to have a film thickness of 3 μm, and the alignment layer was formed by irradiating with ultraviolet rays so ^{that the integrated light amount was 20 mJ / cm 2.}

The composition for the alignment layer described above is composed of 2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, dipentaerythritol triacrylate, and bis (2-vinyloxyethyl) ether in a ratio of 1: 1: 4: 5. The mixture was mixed at a ratio, and LUCIRIN (registered trademark) TPO was added as a polymerization initiator at a ratio of 4% to the total mass of the obtained mixture.

A liquid crystal composition containing a polymerizable nematic liquid crystal compound (RMM28B, manufactured by Merck & Co., Inc.) was applied onto the formed alignment layer by die coating.

To prepare the liquid crystal composition, as a heat medium, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone (CHN) having a boiling point of 155 ° C. are used in a mass ratio (MEK: MIBK: CHN) of 35. A mixed heat medium mixed at a ratio of: 30: 35 was used. Then, the liquid crystal composition prepared so that the solid content per 100 g of the liquid crystal composition was 1 to 1.5 g was applied onto the alignment layer so that the coating amount before drying was 4 to 5 g.

After coating the liquid crystal composition on the oriented layer, the obtained coated layer was dried at a drying temperature of 75 ° C. and a drying time of 120 seconds. Then, the liquid crystal compound was polymerized and cured by irradiation with ultraviolet rays (UV). In this way, a second film composed of a retardation layer, an alignment layer and a transparent film was obtained. This retardation layer satisfied the relationship of nz> nx = ny and was a positive C layer. The total thickness of the retardation layer and the alignment layer was 4 μm.

(Manufacturing method of energy ray active adhesive)
As the adhesive, the compounds were mixed in the proportions shown in Table 1 below. In Table 1, the ratio of the compound is expressed by the number of parts by mass.

３’，４’−エポキシシクロヘキシルメチル ３，４−エポキシシクロヘキサンカルボキシレート（ダイセル化学工業株式会社製「ＣＥＬ２０２１Ｐ」、脂環式ジエポキシ） The details of the compounds in Table 1 are as follows.
Compound 1: Compound 1:

3', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate ("CEL2021P" manufactured by Daicel Chemical Industries, Ltd., alicyclic diepoxy)

ネオペンチルグリコールジグリシジルエーテル（ＮＰＧＤＧＥ）（ナガセケムテックス株式会社製「EX-211」、ジエポキシ） Compound 2:

Neopentyl Glycol Diglycidyl Ether (NPGDGE) ("EX-211" manufactured by Nagase ChemteX Corporation, Diepoxy)

２−エチルヘキシルグリシジルエーテル（ＥＨＧＥ）（東京化成工業株式会社製、モノエポキシ） Compound 3:

2-Ethylhexyl glycidyl ether (EHGE) (manufactured by Tokyo Chemical Industry Co., Ltd., monoepoxy)

Initiator: Cationic initiator SP-500 (solid content 2.25 parts) manufactured by ADEKA CORPORATION
Sensitizer: Kawasaki Kasei Chemicals Co., Ltd. Sensitizer DEN
Leveling agent: Leveling agent KRM-430 manufactured by ADEKA CORPORATION

(Manufacturing method of optical laminate)
Using the manufacturing apparatus shown in FIG. 1, an optical laminate is manufactured by the following procedure. However, the roll used in the manufacturing apparatus is the roll 50 as shown in FIG. 5A. Specifically, the roll has a second discharge passage connected to the main passage. The diameter of the pipe of the second discharge passage is 10 mm. The outermost diameter of the roll is 150 mm, and the length of the roll is 300 mm. The outer diameter of the first passage of the main passage (inner diameter of the outer pipe) is 128 mm, and the inner diameter of the first passage of the main passage (outer diameter of the inner pipe) is 100 mm. The cross-sectional area of the first passage of the main passage is 0.0050 m ² .

Then, the surfaces of the first film and the second film are subjected to corona treatment while continuously transporting the first film and the second film. While continuing to convey the first film and the second film, an energy ray-active adhesive is applied to the corona-treated surface of the first film using a coating machine (bar coater), and then the first film and the second film are applied. Are laminated and passed between a pair of bonding rolls to obtain a bonding film having a layer structure of a first film / a coating layer / a second film.

While transporting the obtained bonded film at a speed of 10 m / min, ultraviolet rays from the activation treatment device are brought into close contact with the roll body so that the integrated light amount with respect to the bonded film is 250 mJ / cm ^{2 (UVB)).} The optical laminate is obtained by irradiating with the above and curing the adhesive. The activation processing device uses a high-pressure mercury lamp manufactured by Igraphics.

1 roll device 2 roll 3 heat medium circulation unit (heat medium circulation means)
4 Roll main body 4a Outer peripheral surface 4b End surface 5 Shaft 10 Heat medium flow path 10a Main passage 10b Introduction passage 10c First discharge passage 10d Second discharge passage 15 Optical laminate manufacturing equipment 16 Laminating device 17 Control device 11 Adhesion Agent coating equipment 13 Activation processing equipment 20 Winding roll 21 1st bonding roll 22 2nd bonding roll 31 1st film (polarizing film)
32 Second film (transparent film)
33 Laminated film 34 Optical laminate (polarizing plate)
50 roll 51 outer pipe (roll body)
51a Outer peripheral surface 52 Inner pipe (roll body)
53 1st shaft part 54 2nd shaft part 55 Heat medium flow path 55a 1st passage (main passage)
55b 2nd passage (main passage)
55c 3rd passage (main passage)
55d Introduction passage 55e First discharge passage 55f Second discharge passage C1 Rotation axis

Claims (9)

A method for manufacturing an optical laminate having at least one layer made of an optical film.
The bonding process of forming a bonding film by bonding two films that are different from each other via an energy ray-active adhesive, and
It is provided with an activation treatment step of irradiating the bonded film with energy rays on the roll while bringing the bonded film into contact with the roll to activate the adhesive.
Inside the roll, a heat medium flow path through which a heat medium flows is provided, and the roll includes a roll main body portion in which the roll center line coincides with the rotation axis and the outer peripheral surface portion extends in a cylindrical shape. The temperature of the surface of the roll is adjusted by the heat medium circulation means for circulating the heat medium in the flow path.
The heat medium flow path extends along the rotation axis so as to correspond to the entire outer peripheral surface portion of the roll main body portion, and extends on the rotation axis and communicates with the main passage to the main passage. An introduction passage for introducing the heat medium into the passage, a first discharge passage extending on the rotation axis and communicating with the main passage to discharge the heat medium flowing into the main passage, and one end of the main passage. It is provided with a second discharge passage that communicates with the main passage on the downstream side and at a position close to the outer peripheral surface portion, while the other end communicates with the first discharge passage.
The activation treatment step is a method for manufacturing an optical laminate, which comprises an operation of flowing a heat medium into the heat medium flow path while rotating the roll main body portion. A method for manufacturing an optical laminate having at least one layer made of an optical film.
The bonding process of forming a bonding film by bonding two films that are different from each other via an energy ray-active adhesive, and
It is provided with an activation treatment step of irradiating the bonded film with energy rays on the roll while bringing the bonded film into contact with the roll to activate the adhesive.
Inside the roll, a heat medium flow path through which a heat medium flows is provided, and the roll includes a roll main body portion in which the roll center line coincides with the rotation axis and the outer peripheral surface portion extends in a cylindrical shape. The temperature of the surface of the roll is adjusted by the heat medium circulation means for circulating the heat medium in the flow path.
The heat medium flow path includes a main passage extending along the rotation axis so as to correspond to the entire outer peripheral surface portion of the roll main body portion, and a discharge passage for discharging the heat medium flowing through the main passage. Ori,
The activation treatment step includes an operation of flowing a heat medium into the heat medium flow path while rotating the roll main body portion, and the volume of the heat medium flowing in the main passage is the total volume of the main passage. A method for manufacturing an optical laminate, which is maintained at 90% or more and 100% or less. The method for producing an optical laminate according to claim 1 or 2, wherein the activation treatment step is performed in a state where the temperature distribution in the width direction of the surface of the roll main body portion is maintained at 3.5 ° C. or lower. The method for producing an optical laminate according to any one of claims 1 to 3, further comprising a step of irradiating the bonded film that has undergone the activation treatment with energy rays. An apparatus for manufacturing an optical laminate having at least one layer made of an optical film.
A bonding device that forms a bonding film by bonding two films that are different from each other via an energy ray-active adhesive.
The roll that comes into contact with the bonding film and
A device for activating the adhesive by irradiating the bonded film with energy rays on the roll is provided.
Inside the roll, a heat medium flow path through which a heat medium flows is provided, and the roll includes a roll main body portion in which the roll center line coincides with the rotation axis and the outer peripheral surface portion extends in a cylindrical shape. The temperature of the surface of the roll is adjusted by the heat medium circulation means for circulating the heat medium in the flow path.
The heat medium flow path extends along the rotation axis so as to correspond to the entire outer peripheral surface portion of the roll main body portion, and extends on the rotation axis and communicates with the main passage to the main passage. An introduction passage for introducing the heat medium into the passage, a first discharge passage extending on the rotation axis and communicating with the main passage to discharge the heat medium flowing into the main passage, and one end of the main passage. An apparatus for manufacturing an optical laminate, comprising a second discharge passage that communicates with a main passage on the downstream side and at a position close to the outer peripheral surface portion, while the other end communicates with the first discharge passage. The claim further comprises a control device for controlling the temperature distribution in the width direction of the surface of the roll main body to be maintained at 3.5 ° C. or lower when the adhesive is activated by the activation treatment device. 5. The apparatus for manufacturing an optical laminate according to 5. The roll main body has an outer pipe and an inner pipe, and has an outer pipe and an inner pipe.
The apparatus for manufacturing an optical laminate according to claim 5 or 6, wherein the space between the outer tube and the inner tube constitutes a part of the heat medium flow path. The apparatus for manufacturing an optical laminate according to any one of claims 5 to 7, wherein the second discharge passage is provided in two or more. The apparatus for manufacturing an optical laminate according to claim 8, wherein the second discharge passages are provided at equal intervals around the center of rotation.

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