TW202212156A - Method for manufacturing optical laminate and manufacturing device of optical laminate - Google Patents

Abstract

An object of the present invention is to provide a method for manufacturing an optical laminate which can reduce the temperature unevenness in the width direction of a surface of roll and reduce a problem of the quality of bonded film, and a manufacturing device of the optical laminate.

The method for manufacturing the optical laminate comprises a bonding step of forming a bonding film by bonding two films different from each other via an energy ray-active adhesive, and an activation treatment step of irradiating the bonding film with energy rays on the roll while bringing the bonding film into contact with the roll to activate the adhesive;

wherein a heat medium flow path through which the heat medium flows is provided inside the roll, the roll has a roll body portion in which the roll center line coincides with the rotation axis and the outer peripheral surface portion extends in a cylindrical shape, and the temperature of the surface of the roll is regulated by the heat medium circulation means for circulating the heat medium in the heat medium flow path;

The heat medium flow path has a main passage extending along the axis of rotation so as to correspond to the entire outer peripheral surface of the roll body, an introduction passage which extends on the axis of rotation and communicates with the main passage to introduce a heat medium into the main passage, a first discharge passage which 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 a second discharge passage in which one end communicates with the main passage on the downstream side of the main passage and at a position close to the outer peripheral surface, while the other end communicates with the first discharge passage; and

the activation treatment step contains an operation of flowing a heat medium into the heat medium flow path while rotating the roll main body.

Description

Manufacturing method of optical laminated body and manufacturing apparatus of optical laminated body

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

In the manufacture of optical laminates such as polarizing plates, after bonding the optical films constituting each layer of the optical laminate with an energy ray-active adhesive, activation treatment is performed while conveying the resulting bonded films. This activation treatment is performed by irradiating energy rays to the bonding film passing over the roll. Irradiation of this energy ray is usually performed while cooling the laminated film on a cooled roll in order to avoid problems of the quality of the laminated film such as deformation of the laminated film or uneven hardening.

Conventionally, as a method of cooling a roll, for example, as shown in JP 2019-3210 A (Patent Document 1), it is known to flow a heat medium in a roll.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2019-3210

However, when the heat medium is flowed in the roll as in the past, there is a fear that temperature unevenness occurs in the width direction of the surface of the roll. Next, the temperature nonuniformity in the width direction of the roll surface causes the reaction rate of the adhesive to be nonuniform in the width direction of the bonding film, which may cause a problem of the quality of the bonding film.

Therefore, the present disclosure is to provide a method for producing an optical layered product and an apparatus for producing an optical layered product, which reduce the temperature unevenness in the width direction of the roll surface and reduce the quality problem of the bonding film.

With regard to the aforementioned problems, the inventors of the present application found that the occurrence of temperature unevenness was caused by the gas accompanying the circulation of the heat medium, and finally completed the present invention.

The method for producing an optical laminate of the present invention is a method for producing an optical laminate having at least one layer composed of an optical film, comprising:

The step of laminating is to make two films different from each other stick together through the adhesive of the energy ray active type, and form a lamination film;

In the activation treatment step, the bonding film is irradiated with energy rays on the roller while the bonding film is brought into contact with the roller, and the activation treatment of the adhesive is performed;

The inside of the roller is provided with a heat medium flow path for the heat medium to flow, and the roller system has a roller body portion whose "roll center line is aligned with the rotation axis and the outer peripheral surface extends in a cylindrical shape". The heat medium circulation means for circulating the heat medium through the heat medium flow path, so as to adjust the temperature of the surface of the roller;

The heat medium flow path is provided with: a main passage extending along the rotational axis so as to correspond to the entire area of the outer peripheral surface of the roller body; and an introduction passage extending on the rotational axis and communicating with the roller body. The main passage is used to introduce the heat medium into the main passage; the first discharge passage is extended on the rotation axis and communicated with the main passage to discharge the heat medium flowing in the main passage; the second discharge passage is one end On the downstream side of the main passage, and communicated with the main passage at a position close to the outer peripheral surface portion, on the other hand, the other end is communicated with the first discharge passage;

The activation treatment step includes an operation of causing a heat medium to flow in the heat medium flow path while rotating the roll body.

According to the above-mentioned aspect, since the activation treatment step includes the operation of causing the heat medium to flow in the heat medium flow path while rotating the roll body, it is possible to discharge the gas in the main passage from the second discharge passage while The heat medium flows in the roll body. Thereby, the temperature unevenness in the width direction of the surface of the roller caused by the gas in the roll can be reduced, the reaction speed of the adhesive in the width direction of the lamination film can be made slightly uniform, and the quality of the lamination film can be reduced.

Moreover, the manufacturing method of the optical laminated body of this invention is the manufacturing method of the optical laminated body which has at least 1 layer which consists of an optical film, and comprises:

The step of laminating is to make two films different from each other stick together through the adhesive of the energy ray active type, and form a lamination film;

In the activation treatment step, the bonding film is irradiated with energy rays on the roller while the bonding film is brought into contact with the roller, and the activation treatment of the adhesive is performed;

The inside of the roller is provided with a heat medium flow path for the heat medium to flow, and the roller system has a roller body portion with "the center line of the roller coincides with the rotation axis and the outer peripheral surface extends in a cylindrical shape". The medium flow path makes the heat medium circulation means to circulate the heat medium to adjust the temperature of the surface of the roller;

The heat medium flow path includes: a main passage extending along the axis of rotation so as to correspond to the entire area of the outer peripheral surface of the roller body; a discharge passage for discharging the heat medium flowing in the main passage;

The activation treatment step includes an operation of making the heat medium flow in the heat medium flow path while rotating the roll body, and the volume of the heat medium flowing in the main passage is maintained at a volume equal to the total volume of the main passage. More than 90% and less than 100%.

According to the aforementioned aspect, the activation treatment step includes the operation of causing the heat medium to flow in the heat medium flow path while rotating the roller body, and the volume of the heat medium flowing in the main passage is maintained at the total volume of the main passage. Since the volume is 90% or more and 100% or less, the heat medium can flow in the roller body while the gas in the main passage is discharged from the discharge passage. Thereby, the temperature unevenness in the width direction of the surface of the roller caused by the gas in the roller can be reduced, and the reaction speed of the adhesive in the width direction of the lamination film can be slightly uniform, so as to reduce the quality of the lamination film. .

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

According to the above-mentioned embodiment, the activation treatment step is performed so that the temperature distribution in the width direction of the surface of the roller body is maintained at 3.5°C or lower, so that the temperature unevenness in the width direction of the surface of the roller can be further reduced, and more The problem of reducing the quality of the lamination film.

One embodiment of the manufacturing method of an optical laminated body includes the step of irradiating the energy ray on the bonding film 33 which obtained the activation process.

According to the above-mentioned embodiment, since the step of irradiating the energy ray on the activated lamination film is further included, the activation treatment of the adhesive can be performed more reliably.

Moreover, the manufacturing apparatus of the optical laminated body which concerns on one aspect of this disclosure is the manufacturing apparatus of the optical laminated body which has at least one layer which consists of an optical film, and is provided with:

The laminating device is for laminating two mutually different films through an energy ray-active adhesive to form a laminating film;

A roller is in contact with the aforementioned laminating film;

The activation treatment device is to perform activation treatment of the adhesive agent while irradiating the bonding film with energy rays on the roller;

The inside of the roller is provided with a heat medium flow path for the heat medium to flow, and the roller system has a roller body portion with "the center line of the roller coincides with the rotation axis and the outer peripheral surface extends in a cylindrical shape". The medium flow path makes the heat medium circulation means to circulate the heat medium to adjust the temperature of the surface of the roller;

The heat medium flow path is provided with a main passage extending along the rotation axis so as to correspond to the entire area of the outer peripheral surface of the roller body portion, and an introduction passage extending on the rotation axis and communicating with the rotation axis. The main passage is used to introduce the heat medium into the main passage; the first discharge passage is extended on the rotation axis and communicated with the main passage to discharge the heat medium flowing in the main passage; the second discharge passage is one end On the downstream side of the main passage, it communicates with the main passage at a position close to the outer peripheral surface portion, and the other end communicates with the first discharge passage.

According to the above aspect, since the heat medium flow path of the roller has the second discharge passage communicating with the main passage, the heat medium can flow in the roller body while discharging the gas in the main passage from the second discharge passage. In this way, the temperature unevenness of the gas in the roll in the width direction of the surface of the roll can be reduced, and the reaction speed of the adhesive in the width direction of the lamination film can be slightly uniform, so as to reduce the quality of the lamination film. .

Preferably, in one embodiment of the manufacturing apparatus of the optical layered body, it is further provided with a control device, which controls the activation of the adhesive agent by the activation treatment device so as to cause the roller body part to be activated. The temperature distribution in the width direction of the surface was maintained at 3.5°C or lower.

According to the above-mentioned embodiment, when the activation treatment of the adhesive is performed by the activation treatment device, the temperature distribution in the width direction of the surface of the roller body portion can be controlled to further reduce the temperature unevenness of the surface of the roller in the width direction, and It also reduces the quality of the lamination film.

Preferably, in an embodiment of the apparatus for manufacturing the optical laminate, the roller body has an outer tube and an inner tube,

The space between the outer tube and the inner tube constitutes a part of the flow path of the heat medium.

According to the above-mentioned embodiment, since the space between the outer tube and the inner tube constitutes a part of the flow path of the heat medium, the heat medium can only flow in a part of the space in the outer tube. Therefore, the flow rate can be increased by a smaller amount of heat medium than with a single-pipe roll of the same diameter.

Preferably, in one embodiment of the manufacturing apparatus of an optical laminated body, two or more said 2nd discharge paths are provided.

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

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

According to the aforementioned embodiment, each of the second discharge passages is formed to pass through the gas pool on the upper part of the roll at short intervals during the rotation operation of the roll, so that the discharge time of the gas accumulated on the upper part of the main passage of each rotation of the roll is increased. , which can effectively fill the main passage with heat medium.

According to the manufacturing method of an optical laminated body and the manufacturing apparatus of an optical laminated body of one aspect of this disclosure, the temperature unevenness of the width direction of the surface of a roll can be reduced, and the problem of the quality of a bonding film can be reduced.

1: Roller device

2: Roller

3: Heat medium circulation unit (heat medium circulation means)

4: Roller body

4a: Peripheral face

4b: End face

5: Shaft

10: Heat medium flow path

10a: Main Path

10b: Import Pathway

10c: 1st discharge passage

10d: Second discharge passage

11: Adhesive coating device

13: Activation treatment device

15: Manufacturing equipment for optical laminates

16: Fitting device

17: Controls

20: Winding roller

21: The first bonding roller

22: The second bonding roller

31: The first film (polarizing film)

32: Second film (transparent film)

33: Lamination film

34: Optical laminate (polarizing plate)

50: Roller

51: Outer tube (roller body)

51a: Peripheral face

52: Inner tube (roller body part)

53: 1st shaft

54: 2nd shaft

55: Heat medium flow path

55a: 1st channel (main channel)

55b: 2nd channel (main channel)

55c: 3rd channel (main channel)

55d: Introductory pathway

55e: 1st discharge passage

55f: Second discharge passage

C1: Rotation axis

FIG. 1 is a schematic diagram showing an embodiment of an apparatus for producing an optical laminate.

Fig. 2 is a schematic cross-sectional view of one embodiment of the roll.

FIG. 3 is a cross-sectional view taken along line II-II of FIG. 2 .

FIG. 4 is an enlarged view of part III of FIG. 2 .

FIG. 5A is a schematic cross-sectional view showing another embodiment of the roller.

FIG. 5B is a cross-sectional view taken along line A-A of FIG. 5A .

Hereinafter, the manufacturing method of the optical laminated body and the manufacturing apparatus of the optical laminated body of an aspect of this disclosure are demonstrated in detail by the embodiment shown in figure. In addition, the drawings include some schematic diagrams, and sometimes do not reflect the actual size or ratio.

(implementation type)

(Manufacturing device of optical laminate)

FIG. 1 is a schematic diagram showing an embodiment of an apparatus for producing an optical laminate. As shown in FIG. 1, the manufacturing apparatus 15 of the optical laminated body is provided with: the bonding apparatus 16, the 1st film 31 and the 2nd film 32 which are different from each other are bonded together to form the bonding film 33; In the bonding film 33 ; the activation treatment device 13 is used to irradiate the bonding film 33 with energy rays to form the optical layered body 34 , and the control device 17 is used to control the roll 2 .

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 layered body 34 is a polarizing plate. The films were fed in the direction indicated by the arrows in FIG. 1 .

Optical films are resin films that exhibit optical properties, such as polarizing films and retardation films. The polarizing film is, for example, formed by applying iodine or a dichroic dye to a uniaxially stretched polyvinyl alcohol film, followed by boric acid treatment.

Examples of the transparent film include thermoplastic resins such as amorphous polyolefin-based resin films, polyester-based resin films, acrylic resin films, polycarbonate-based resin films, polysilicon-based resin films, and alicyclic polyimide-based resin films. . The transparent film is preferably a resin film with low moisture permeability. As a transparent film system, a cellulose acetate-type resin film, such as a triacetate cellulose film and a diacetate cellulose film, is mentioned more.

The optical film may be a single layer or a laminate. The type of the optical film system is not particularly limited as long as it is a film showing optical properties. The resulting optical laminate may have a As a film showing optical properties, if it is a film showing optical properties, for example, it may be an optical film such as a retardation film, a protective film, the above-mentioned polarizing film, or an optical laminate in which these films or thermoplastic resins are laminated. That is, the optical laminated system should just have at least one layer which consists of an optical film.

The laminating apparatus 16 includes: the adhesive coating apparatus 11 for coating the adhesive on one side of the first film 31; The bonding roll 21 and the second bonding roll 22 . The adhesive is an energy ray active adhesive.

From the viewpoints of weather resistance, refractive index, cationic polymerizability, and the like, the adhesive is, for example, an epoxy resin that does not contain an aromatic ring in the molecule. As epoxy resins, for example, hydrogenated epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, and the like are used. Polymerization initiators are added to epoxy resins, such as photocationic polymerization initiators for polymerization by irradiation with active energy rays, thermal cationic polymerization initiators for polymerization by heating, and other additives (sensitizers, etc.).

The roller 2 is driven to rotate so that the center line of the roller 2 coincides with the axis of rotation, and the bonding film 33 is conveyed while being brought into contact with the surface of the roller 2 . The roll 2 is in contact with the bonding film 33 . That is, when the roller 2 irradiates the bonding film 33 with energy rays from the activation treatment device 13 , it is difficult to heat the bonding film 33 by being in contact with the bonding film 33 . The roller 2 has a heat medium flow path through which the heat medium flows, and the bonding film 33 is cooled by the heat medium flowing in the heat medium flow path. The heat medium system is, for example, a refrigerant such as water.

The roller 2 is provided with a roller body portion whose outer peripheral surface portion extends in a cylindrical shape. The surface temperature of the roll 2 is regulated by a 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 is controlled by the control device 17 .

The heat medium flow path is provided with: a main passage extending along the rotation axis so as to correspond to the entire area of the outer peripheral surface of the roller body; an introduction passage extending on the rotation axis and communicating with the main passage. The heat medium is introduced into the main passage; the first discharge passage extends on the rotation axis and communicates with the main passage to discharge the heat medium flowing in the main passage; the second discharge passage has one end on the downstream side of the main passage , and communicates with the main passage at a position close to the outer peripheral surface, and on the other hand, the other end communicates with the first discharge passage.

Since the heat medium flow path of the roller 2 has a second discharge passage that communicates with the main passage, the heat medium can flow in the roller body portion while the gas in the main passage is discharged from the second discharge passage. The gas is, for example, air. The second exhaust passage system exhausts 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 can be reduced, the reaction speed of the adhesive agent in the width direction of the lamination film 33 can be made slightly uniform, and the temperature of the lamination film 33 can be reduced. quality issue.

In addition, since the second discharge passage communicates with the main passage at a position close to the outer peripheral surface, when the rotating shaft center of the roller 2 is horizontally disposed and used, the aggregates can be efficiently discharged from the second discharge passage to the outer peripheral surface side of the main passage. gas.

In addition, since the second exhaust passage communicates with the downstream side of the main passage, the gas can be efficiently exhausted according to the flow of the heat medium.

The roller body may be constituted by, for example, a single tube of the outer tube, and in this case, the space inside the outer tube is a part (main passage) constituting the flow path of the heat medium. In addition, the roller body may be constituted by, for example, a double tube of an outer tube and an inner tube, and in this case, the space between the outer tube and the inner tube constitutes a part (main passage) of the heat medium flow path. The space between the outer tube and the inner tube is formed in an annular shape when viewed from the rotational axis direction of the roller 2 .

The activation treatment device 13 is arranged toward the roll 2 . The activation treatment device 13 irradiates the bonding film 33 with energy rays on the roll 2 to perform activation treatment of the adhesive. That is, the activation treatment device 13 polymerizes and hardens the adhesive by irradiation of energy rays. In this way, the optical layered body 34 formed by the activation treatment of the activation treatment device 13 is wound by the winding roll 20 . In addition, the energy rays are usually irradiated not only on the roll 2 but also on the periphery of the roll 2 .

The activation treatment device 13 has, for example, a light emission distribution at 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 controls the temperature distribution (maximum temperature difference) in the width direction of the surface of the roller body to be kept below 3.5°C, more preferably 2°C, when the activation treatment device 13 performs the activation treatment of the adhesive. the following status. That is, the control device 17 preferably sets the difference between the maximum temperature in the width direction of the surface of the roll body and the minimum temperature in the width direction of the surface of the roll body 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 problem of the quality of the bonding film 33 can be further reduced.

Specifically, the control device 17 is constituted by a central processing device. The control device 17 adjusts the flow rate of the heat medium in the roll 2, the flow rate of the heat medium in the roll 2, or the amount of heat medium in the roll 2, for example, by controlling the heat medium circulation means, so that the The temperature distribution in the width direction of the surface is maintained at 3.5°C or lower.

Preferably, the main body of the tie-roller has an outer tube and an inner tube, and the space between the outer tube and the inner tube is a part of the flow path of the heat medium. According to this, the heat medium can flow only in a part of the space inside the outer tube, so that the flow rate can be increased by a smaller amount of heat medium compared with the roller 2 of a single tube with 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 discharged efficiently. Preferably, the second discharge passages are provided around the rotation axis at equal intervals. According to this, when the roller 2 rotates, the second discharge passages pass through the gas pool on the upper part of the roller at short intervals, so that the discharge time of the gas accumulated on the upper part of the main passage of each rotation of the roller 2 is increased, which can effectively The ground is filled with heat medium in the main passage.

In addition, the manufacturing apparatus of this disclosure is not limited to the above-mentioned embodiment, and the design can be changed in the range which does not deviate from the gist of this disclosure. The said manufacturing apparatus may each have two or more activation processing apparatuses or rolls. In the aforementioned manufacturing apparatus, a plurality of activation treatment apparatuses may be arranged to face one roll.

(Manufacturing method of optical laminate)

Next, an embodiment of the manufacturing method of the optical layered body will be described with reference to FIG. 1 .

First, the bonding film 33 is formed by bonding the first film 31 and the second film 32 with an energy ray active adhesive interposed therebetween. This is called the fitting step. After that, the bonding film 33 is brought into contact with the roll 2, and the bonding film 33 is irradiated with energy rays on the roll 2, and the activation treatment of the adhesive is performed. This is called an activation treatment step.

Here, a heat medium flow path for allowing the heat medium to flow is provided inside the roll 2 . The roll 2 is provided with the roll main body part which the roll center line and the rotating shaft center correspond, and the outer peripheral surface part is extended in a cylindrical shape. The surface temperature of the roller 2 is regulated by the heat medium circulation means for circulating the heat medium in the heat medium flow path.

The heat medium flow path is provided with: a main passage extending along the rotation axis so as to correspond to the entire area of the outer peripheral surface of the roller body; an introduction passage extending on the rotation axis and communicating with the main passage to The main passage introduces heat medium; the first discharge passage is tied to the rotating shaft The second discharge passage is one end on the downstream side of the main passage and communicates with the main passage at a position close to the outer peripheral surface, and on the other hand, the other One end communicates with the first discharge passage.

Next, the activation treatment step includes an operation of rotating the roller body while flowing the heat medium in the heat medium flow path.

According to this, since the activation treatment step includes the operation of rotating the roll body and flowing the heat medium in the heat medium flow path, the gas in the main passage can be discharged from the second discharge passage, and the heat in the roll body can be discharged at the same time. medium flow. Therefore, the temperature unevenness in the width direction of the surface of the roll 2 caused by the gas in the roll 2 can be further reduced, the reaction speed of the adhesive agent in the width direction of the lamination film 33 can be made slightly uniform, and the temperature of the lamination film 33 can be reduced. quality issue.

Preferably, in the activation treatment step, the volume of the heat medium flowing in the main channel relative to the total volume of the main channel is maintained at 90% or more and 100% or less, more preferably 95% or more and 100% 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 problem of the quality of the bonding film 33 can be further reduced.

Here, the discharge amount of gas in the main passage can be adjusted by appropriately adjusting the flow rate of the heat medium flowing in the heat medium flow passage, the rotational speed of the roller body, and the size of the cross-sectional area of each discharge passage. That is, the volume of the heat medium flowing in the main passage can be adjusted by exhausting the gas in the main passage. As long as the rollers of the manufacturing apparatus of the present disclosure are used, the volume of the heat medium flowing in the main passage can be easily adjusted.

The activation treatment step is preferably performed while maintaining the temperature distribution in the width direction of the surface of the roll body at 3.5° C. or lower (more preferably, 2° C. or lower). Based on this, the The problem of reducing the temperature unevenness in the width direction of the surface of the roll 2 and further reducing the quality of the bonding film 33 is reduced.

In the above-mentioned activation treatment step, when the bonding film 33 is irradiated with energy rays a plurality of times, the energy rays are usually irradiated using a manufacturing apparatus equipped with two or more activation treatment apparatuses. This energy ray irradiation is performed while passing through one roll facing two or more activation treatment apparatuses, and an apparatus having two or more rolls facing one or a plurality of activation treatment apparatuses may be used to pass the bonding film through A plurality of rolls are performed while performing.

In this embodiment, the step of irradiating energy rays on the activation-treated adhesive film 33 is further included. Thereby, the activation process of an adhesive agent can be performed more reliably.

In this embodiment, the step of irradiating the bonding film 33 with the activation treatment with energy rays is the same as the activation treatment described above in that it is carried out on a roller having a different configuration from that in the activation treatment step described above. The energy ray irradiation in the steps is different.

In addition, the manufacturing method of this disclosure is not limited to the above-mentioned embodiment, and the design can be changed in the range which does not deviate from the gist of this disclosure. For example, the manufacturing method of the present disclosure is not limited to be implemented by the manufacturing device 15 of FIG. 1 , but can also be implemented by other different devices.

Moreover, another embodiment of the manufacturing method of an optical layered body includes a bonding step and an activation treatment step, a heat medium flow path for allowing a heat medium to flow is provided inside the roll, and the roll system includes: a roll center line and a rotation The roller body part with the same shaft center and the outer peripheral surface extending in a cylindrical shape adjusts the surface temperature of the roller by means of a heat medium circulation which circulates 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 area of the outer peripheral surface of the roller body portion, and a discharge passage for discharging the heat medium flowing in the main passage. That is, the discharge passage is not limited to the aforementioned first discharge passage and the aforementioned For example, the second discharge passage may not be the aforementioned second discharge passage. The activation treatment step includes an operation of flowing the heat medium in the heat medium flow path while rotating the roll body. 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 of the total volume of the main passage, preferably 95% or more and 100% or less.

According to this, the gas in the main passage can be discharged from the discharge passage, and at the same time, the heat medium can flow in the roller body. Therefore, it is possible to reduce the temperature unevenness in the width direction of the surface of the roll caused by the gas in the roll, and to make the reaction rate of the adhesive slightly uniform in the width direction of the lamination film, and reduce the quality of the lamination film.

(Construction of Roller)

FIG. 2 is a schematic cross-sectional view of an example of an apparatus equipped with a roll applicable to the manufacturing method of the present disclosure (hereinafter, this roll may be referred to as a "roll apparatus 1".). As shown in FIG. 2 , the roller device 1 is used to adjust the temperature of the bonding film W1 in contact with the continuously conveyed bonding film W1 (the bonding film 33 in FIG. 1 ). The roll apparatus 1 is contained in the manufacturing apparatus 15 of the said optical laminated body.

The roller device 1 is provided with: the above-mentioned roller 2, which has a heat medium flow path 10 inside which the heat medium H1 flows, and is rotatable around the rotation axis C1; and a heat medium circulation unit 3 (the aforementioned heat medium circulation means) , which circulates the heat medium H1 in the heat medium flow path 10 .

The roller 2 is provided with: a roller body portion 4 formed of a metal material, the center line of the roller being aligned with the rotation axis C1 and the outer peripheral surface portion 4a extending in a cylindrical shape; and a pair of shaft portions 5, which are integrally Provided on each end surface portion 4b of the roller body portion 4, and the axis center line is consistent with the rotation axis C1; a pair of rotary joints 6, which are connected to each axis portion 5 and the heat medium circulation unit 3; each axis portion 5 is separated from The bearing B1 is rotatably supported by the support housing 7 .

The heat medium flow path 10 includes: a main passage 10a formed inside the roller body portion 4; an introduction passage 10b extending linearly on the rotation axis C1 of the one shaft portion 5 and communicating with the main passage 10a; The first discharge passage 10c 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 area of the outer peripheral surface portion 4a.

The introduction passage 10b has a circular cross-sectional shape and a cross-sectional area set narrower than the main passage 10a, and introduces the heat medium H1 discharged from the heat medium circulation unit 3 into the main passage 10a.

The first discharge passage 10c has a circular cross-sectional shape and a cross-sectional area set narrower than the main passage 10a so that the heat medium H1 in the main passage 10a is discharged to the heat medium circulation unit 3 . That is, the cross-sectional area of the 1st discharge passage 10c is narrower than the cross-sectional area of the part extended so that it may correspond to the whole area|region of the outer peripheral surface part 4a along the rotation axis C1 of the main passage 10a.

The heat medium circulation unit 3 circulates the heat medium H1 from one end side of the roll 2 to the other end side, and the heat medium H1 passes through the introduction passage 10b, the main passage 10a and the first discharge passage 10c in this order inside the roll 2.

In the inside of the other end surface part 4b of the roller main body part 4, the 2nd discharge passage 10d extended in an L-shape when viewed from the front is formed. As shown in FIGS. 2 to 4 , the second discharge passage 10d has one end connected to the main passage 10a downstream of the main passage 10a of the roller body portion 4 and communicating with the position close to the outer peripheral surface portion 4a, and the other end. It communicates with the upstream side of the 1st discharge passage 10c, and is formed in 12 places 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 of the roll device 1 is operated. In this way, the heat medium H1 flows through the introduction passage 10b of the roller 2, the main passage 10a, and the first discharge passage 10c in this order.

Then, the roller 2 is rotated toward one side (arrow R1 in FIG. 3 ) around the rotation axis C1, and is brought into contact with the continuously conveyed bonding film W1. At this time, inside the roller 2, the heat medium H1 flows through the introduction passage 10b, the main passage 10a, and the first discharge passage 10c in this order. Next, the gas in the main passage 10a is discharged from the second discharge passage 10d, and the heat medium H1 is made to flow in the roll body 4 at the same time. The heat medium H1 is preferably circulated so as to be in contact with the entire back surface of the outer peripheral surface portion 4a of the roller body portion 4 at all times. If the heat medium H1 is continuously circulated in contact with the entire back surface of the outer peripheral surface portion 4a, the outer peripheral surface portion 4a of the roller body portion 4 is uniformly cooled, and the temperature distribution unevenness caused by the bonding film W1 of the contact roller 2 can be avoided. .

Moreover, since gas does not collect in the upper part of the roll main body part 4, the time until the outer peripheral surface part 4a is cooled to a desired temperature can be shortened, and the bonding film W1 can be cooled efficiently.

Moreover, since two or more second discharge passages 10d are formed at equal intervals around the rotation axis C1, each second discharge passage 10d becomes an air pool passing through the upper part of the roller 2 at short intervals during the rotation operation of the roller 2. Therefore, the discharge time of the gas accumulated in the upper portion of the main passage 10a for each rotation of the roller 2 is increased, and the main passage 10a can be efficiently filled with the heat medium H1 without a gap.

In addition, since each second discharge passage 10d is formed inside the end surface portion 4b of the roller body 4, the external deformation of the roller 2 is smaller than when the structure having the second discharge passage 10d is attached to the outside of the roller body 4. . Therefore, the entire roll 2 can be made compact, and the space around the roll 2 can be effectively used.

(Other structures of rollers)

FIG. 5A is a schematic cross-sectional view showing another embodiment of the roll that can be applied to the manufacturing method or the manufacturing apparatus of the present disclosure. FIG. 5B is a cross-sectional view taken along line A-A of FIG. 5A . This roll 50 is a double-pipe roll unlike the roll 2 of FIG. 2 which is a single pipe. Hereinafter, only the parts different from the aforementioned roller 2 will be described.

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

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

The main passage is viewed from the direction of the rotation axis C1 of the roller 50, and is connected to the first passage by extending radially from the rotation axis C1 from the first passage 55a having an annular cross-section between the outer tube 51 and the inner tube 52. A plurality of second passages 55b on one end side of 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 are constituted.

The first passage 55a extends along the rotation axis C1 so as to correspond to the entire area of the outer peripheral surface portion 51a of the roller body portion. The second passage 55b and the third passage 55c are formed around the rotation axis C1 at equal intervals, respectively. Each second passage 55b communicates the introduction passage 55d with 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 be narrower in cross section than the first passage 55a. That is, the cross-sectional area of the 1st discharge passage 55e is narrower than the cross-sectional area of the part extended so that it may correspond to the whole area|region of the outer peripheral surface part 51a along the rotation axis C1 of the main passage.

Next, the heat medium is discharged from the first discharge passage 55e through the second passage 55b, the first passage 55a, and the third passage 55c in order from the introduction passage 55d, as indicated by the arrows of the dotted line in FIG. 5A.

The periphery of the second shaft portion 54 is viewed from the direction of the rotational axis C1, and a plurality of second discharge passages 55f extending slightly radially are arranged around the rotational axis C1 at equal intervals. The second discharge passage 55f includes piping. The piping system is formed of, for example, a piping pipe body 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 is on the downstream side of the main passage, and communicates with the main passage (first passage 55a) at a position close to the outer peripheral surface portion 51a, and the other end of the second discharge passage 55f communicates with the first discharge passage 55e.

Furthermore, the operation of discharging the air pool above the main passage (first passage 55a) is the same as that of the roller 2 of FIG. 2, except that the discharge route is changed from the second discharge passage 10d to the second discharge passage 55f , so the detailed description is omitted.

As described above, since the second discharge passage 55f is disposed on the outer side of the roller body portion or the second shaft portion 54, the processing cost is reduced compared to the structure in which the second discharge passage 55f is formed inside the end portion of the roller body portion. It is low, and can be set as the roll 50 which suppresses cost.

(Example)

Next, an Example is demonstrated.

(1st film)

The PVA film with a thickness of 20 μm (average degree of polymerization of about 2400, degree of saponification of 99.9 mol% or more) was uniaxially stretched about 6 times by dry stretching, and then directly maintained in a tensioned state, immersed in 40 ℃ pure water for 40 seconds .

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

Next, the film after the crosslinking treatment was washed with pure water at 8°C for 15 seconds, then dried at 60°C for 50 seconds with a tension of 300 N/m, and then dried at 75°C for 20 seconds. bell. In this way, a polarizing film having a thickness of 7 μm in which directional iodine was adsorbed on the PVA film was obtained.

As a protective film, a cycloolefin-based resin film (COP, ZF-14 made by ZEON Co., Ltd., with a thickness of 13 μm without UV absorption characteristics) was prepared. A water-based adhesive was injected between the obtained polarizing film and the cycloolefin-based resin film, and they 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 including a polarizer layer and a protective layer disposed on one side of the polarizer layer. The thickness of the first film was 20 μm.

In addition, the water-based adhesive was prepared by adding 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 (Taoka Chemical Industry Co., Ltd.) to 100 parts by mass of water. Co., Ltd.; SUMIREZ RESIN (registered trademark) 650; 30% solid content concentration aqueous solution) 1.5 parts by mass was prepared.

(2nd film)

A film formed of a polyethylene terephthalate film having a thickness of 38 μm was prepared as a transparent film. The composition for an alignment layer was applied to one side of the transparent film to a thickness of 3 μm, and ultraviolet rays were irradiated so that the cumulative light intensity was 20 mJ/cm ² to form an alignment layer.

In addition, the composition for the alignment layer is a mixture of 2-phenoxyethyl acrylate, tetrahydrofuran methyl acrylate, dipivalerythritol triacrylate, and bis(2-vinyl acrylate) at a ratio of 1:1:4:5 The oxyethyl) ether was prepared by adding LUCIRIN (registered trademark) TPO as a polymerization initiator at a ratio of 4% with respect to the total mass of the obtained mixture.

On the formed alignment layer, a liquid crystal composition containing a polymerizable nematic liquid crystal compound (manufactured by MERCK, RMM28B) was coated on the alignment layer by die coating.

In the preparation of the liquid crystal composition, a mixed heat medium is used as the heat medium. The mixed heat medium is a mixture of methyl ethyl ketone (MEK) and methyl isobutyl ketone in a mass ratio (MEK:MIBK:CHN) 35:30:35. (MIBK) and cyclohexanone (CHN) with a boiling point of 155°C. Next, the liquid crystal composition is coated on the alignment layer so that the coating weight before drying is 4 to 5 g, and the liquid crystal composition is prepared so that the solid content of the liquid crystal composition is 1 to 1.5 g per 100 g of the liquid crystal composition.

After coating the liquid crystal composition on the alignment layer, the coating layer obtained by drying treatment was set to 75° C. for drying temperature and 120 seconds for drying time. Then, the liquid crystal compound is polymerized and hardened by ultraviolet (UV) irradiation. In this manner, the second film composed of the retardation layer, the alignment layer, and the transparent film was obtained. The retardation layer satisfies the relationship of nz>nx=ny, and is 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)

Compounds were mixed at the ratio shown in Table 1 below as an adhesive. In Table 1, the proportions of the compounds are expressed in parts by mass.

[Table 1]

The details of the compounds in Table 1 are as follows.

Compound 1:

3,4-Epoxycyclohexanecarboxylic acid 3',4'-epoxycyclohexylmethyl ester ("CEL2021P" manufactured by DAICEL Chemical Industry Co., Ltd., alicyclic diepoxide)

Compound 2:

Neopentyl Glycol Diglycidyl Ether (NPGDGE) ("EX-211" manufactured by Nagase Chemtex Co., Ltd., Diepoxide)

Compound 3:

2-Ethylhexylglycidyl ether (EHGE) (manufactured by Tokyo Chemical Industry Co., Ltd., monoepoxide)

Starter: cationic starter SP-500 manufactured by ADEKA Co., Ltd. (solid content 2.25 parts)

Sensitizer: DEN, a sensitizer manufactured by Kawasaki Chemical Industry Co., Ltd.

Leveling agent: Leveling agent KRM-430 manufactured by ADEKA Co., Ltd.

(Manufacturing method of optical laminate)

Using the manufacturing apparatus shown in FIG. 1, the optical laminated body was manufactured in the following procedure. However, the roll system used for this manufacturing apparatus is set to the roll 50 as shown to FIG. 5A. Specifically, the roller system has a second discharge passage connected to the main passage. The diameter of the piping of the second discharge passage was 10 mm. The outermost diameter of the roll was 150 mm, and the length of the roll was 300 mm. The outer diameter of the first passage of the main passage (inner diameter of the outer tube) is 128 mm, and the inner diameter of the first passage of the main passage (outer diameter of the inner tube) is 100 mm. The cross-sectional area of the first passage of the main passage was 0.0050 m ² .

Next, corona treatment is given to the surface of a 1st film and a 2nd film, conveying a 1st film and a 2nd film continuously. Continue to convey the first film and the second film, and at the same time apply the energy ray active adhesive to the corona treated surface of the first film using a coater (bar coater), and then overlap the first film and the second film, It passed between a pair of bonding rolls, and obtained the bonding film which has the layer structure of a 1st film/coating layer/2nd film.

While conveying the obtained lamination film at a speed of 10 m/min, the lamination film was adhered to the roll body part so that the cumulative light amount was 250 mJ/cm ² (UVB)), and ultraviolet rays were irradiated from the activation treatment device to make the adhesive film adhere to the roll body. The agent is cured, whereby an optical layered body is obtained. The activation treatment device used a high-pressure mercury lamp manufactured by EYEGRAPHICS.

2: Roller

11: Adhesive coating device

13: Activation treatment device

15: Manufacturing equipment for optical laminates

16: Fitting device

17: Controls

20: Winding roller

21: The first bonding roller

22: The second bonding roller

31: The first film (polarizing film)

32: Second film (transparent film)

33: Lamination film

34: Optical laminate (polarizing plate)

Claims (9)

A method for producing an optical laminate comprising at least one layer of an optical laminate comprising: The step of laminating is to make two films different from each other stick together through the adhesive of the energy ray active type, and form a lamination film; In the activation treatment step, the bonding film is irradiated with energy rays on the roller while the bonding film is brought into contact with the roller, and the activation treatment of the adhesive is performed; A heat medium flow path for flowing the heat medium is provided inside the roll, the roll is provided with a roll body portion, and the surface of the roll is adjusted by a heat medium circulation means for circulating the heat medium in the heat medium flow path. The temperature of the roller body part is consistent with the center line of the roller and the axis of rotation, and the outer peripheral surface extends into a cylindrical shape; The heat medium flow path is provided with a main passage extending along the rotation axis so as to correspond to the entire area of the outer peripheral surface of the roller body portion, and an introduction passage extending on the rotation axis and communicating with the rotation axis. The main passage is used to introduce the heat medium into the main passage; the first discharge passage is extended on the rotation axis and communicated with the main passage to discharge the heat medium flowing in the main passage; the second discharge passage is one end On the downstream side of the main passage, and communicated with the main passage at a position close to the outer peripheral surface portion, on the other hand, the other end is communicated with the first discharge passage; The activation treatment step includes an operation of causing a heat medium to flow in the heat medium flow path while rotating the roll body. A method for producing an optical laminate comprising at least one layer of an optical laminate comprising: The step of laminating is to make two films different from each other stick together through the adhesive of the energy ray active type, and form a lamination film; In the activation treatment step, the bonding film is irradiated with energy rays on the roller while the bonding film is brought into contact with the roller, and the activation treatment of the adhesive is performed; A heat medium flow path for flowing the heat medium is provided inside the roll, the roll is provided with a roll body portion, and the surface of the roll is adjusted by a heat medium circulation means for circulating the heat medium in the heat medium flow path. The temperature of the roller body part is that the center line of the roller is consistent with the rotation axis and the outer peripheral surface extends into a cylindrical shape; The heat medium flow path is provided with: a main passage extending along the rotation axis so as to correspond to the entire area of the outer peripheral surface of the roller body; and a discharge passage for discharging the heat medium flowing in the main passage ; The activation treatment step includes an operation of causing a heat medium to flow in the heat medium flow path while rotating the roller body, The volume of the heat medium flowing in the main passage is maintained at 90% or more and 100% or less of the total volume of the main passage. The manufacturing method of the optical laminated body of Claim 1 or 2 whose said activation process is performed in the state which maintains the temperature distribution of the width direction of the surface of the said roll main body part at 3.5 degreeC or less. The method for producing an optical laminate according to any one of Claims 1 to 3, further comprising: a step of irradiating an energy ray on the adhesive film subjected to the activation treatment. An apparatus for producing an optical laminate, comprising at least one apparatus for producing an optical laminate having a layer composed of an optical film, comprising: The laminating device is for laminating two mutually different films through an energy ray-active adhesive to form a laminating film; A roller is in contact with the aforementioned laminating film; The activation treatment device is used to irradiate the bonding film with energy rays on the roller to perform activation treatment of the adhesive; A heat medium flow path for flowing the heat medium is provided inside the roll, the roll is provided with a roll body portion, and the surface of the roll is adjusted by a heat medium circulation means for circulating the heat medium in the heat medium flow path. The temperature of the roller body part is that the center line of the roller is consistent with the rotation axis and the outer peripheral surface extends into a cylindrical shape; The heat medium flow path is provided with a main passage extending along the rotation axis so as to correspond to the entire area of the outer peripheral surface of the roller body portion, and an introduction passage extending on the rotation axis and communicating with the rotation axis. The main passage is used to introduce the heat medium into the main passage; the first discharge passage is extended on the rotation axis and communicated with the main passage to discharge the heat medium flowing in the main passage; the second discharge passage is one end On the downstream side of the main passage, it communicates with the main passage at a position close to the outer peripheral surface portion, and the other end communicates with the first discharge passage. The manufacturing apparatus for an optical laminate according to claim 5, further comprising a control device for controlling the surface of the roller body to be activated when the adhesive is activated by the activation treatment device. The temperature distribution in the width direction is maintained at 3.5°C or lower. The apparatus for producing an optical laminate according to claim 5 or 6, wherein the roll body portion has an outer tube and an inner tube, The space between the outer tube and the inner tube constitutes a part of the flow path of the heat medium. The manufacturing apparatus of the optical laminated body of any one of Claims 5-7 in which the said 2nd discharge passage is provided in 2 or more. The manufacturing apparatus of the optical laminated body of Claim 8 in which the said 2nd discharge passage is provided in the periphery of the said rotating shaft center at equal intervals.

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