Manufacturing method of adhesive sheet, manufacturing method of optical film having adhesive sheet, and manufacturing method of picture display unit

Abstract

To provide a manufacturing method of an adhesive sheet suitable for efficiently manufacturing a photo-curing type adhesive sheet.SOLUTION: A manufacturing method of an adhesive sheet includes irradiating a coating layer including a photo-curing type adhesive composition with an active energy ray to form an adhesive sheet from the coating layer. The irradiation of the coating layer with an active energy ray is carried out by two or more times of irradiation including first irradiation and second irradiation later than the first irradiation. In the first irradiation, an integrated light volume of the active energy ray with which the coating layer is irradiated is 7000 mJ / cm2 or less. In the second irradiation, an integrated light volume of the active energy ray with which the coating layer is irradiated is 1600 mJ / cm2 or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing a pressure-sensitive adhesive sheet, a method for producing an optical film with a pressure-sensitive adhesive sheet, and a method for producing an image display device. [Background technology]

[0002] In recent years, image display devices, such as liquid crystal display devices and electroluminescence (EL) display devices (e.g., organic EL display devices and inorganic EL display devices), have rapidly become popular. Image display devices generally include an optical laminate containing optical substrates such as a polarizing film and a retardation film. In an optical laminate containing multiple optical substrates, a bonding layer is usually disposed between adjacent optical substrates to bond them together. One example of the bonding layer is a pressure-sensitive adhesive sheet formed from a pressure-sensitive adhesive composition.

[0003] Patent Document 1 discloses an example of a pressure-sensitive adhesive sheet, which is produced by irradiating a coating layer of a pressure-sensitive adhesive composition disposed between two release liners with light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6688054 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the investigations of the present inventors, there is room for improvement in the conventional photocuring method from the viewpoint of efficiently producing a pressure-sensitive adhesive sheet.

[0006] An object of the present invention is to provide a method for producing a pressure-sensitive adhesive sheet that is suitable for efficiently producing a photocurable pressure-sensitive adhesive sheet. [Means for solving the problem]

[0007] [1] A method for producing a pressure-sensitive adhesive sheet according to an embodiment of the present invention includes: A method for producing a pressure-sensitive adhesive sheet, comprising irradiating a coating layer containing a photocurable pressure-sensitive adhesive composition with active energy rays to form a pressure-sensitive adhesive sheet from the coating layer, the irradiation of the coating layer with the active energy rays is carried out by two or more irradiations including a first irradiation and a second irradiation subsequent to the first irradiation, The cumulative amount of the active energy rays irradiated onto the coating layer in the first irradiation is 7000 mJ / cm 2 is as follows: The cumulative amount of the active energy rays irradiated onto the coating layer in the second irradiation is 1600 mJ / cm 2 That's all. [2] In the manufacturing method according to the above [1], the cumulative light amount of the active energy rays irradiated onto the coating layer in the first irradiation is 4400 mJ / cm 2 It may be the following: [3] In the manufacturing method according to the above [1] or [2], the cumulative light amount of the active energy rays irradiated onto the coating layer in the second irradiation is 3800 mJ / cm 2 It may be more than that. [4] In the manufacturing method described in any one of [1] to [3] above, the first irradiation and the second irradiation may be carried out by irradiating a laminate including a base sheet, the coating layer, and a release liner in this order with the active energy rays. [5] In the manufacturing method according to any one of [1] to [4] above, the light source of the active energy rays in the first irradiation may include a black light, and the light source of the active energy rays in the second irradiation may include a metal halide lamp. [6] In the manufacturing method according to any one of the above items [1] to [5], the manufacturing method may not substantially include a step of heating the coating layer. [7] In the manufacturing method according to any one of [1] to [6] above, the pressure-sensitive adhesive sheet may be formed with a residual monomer content of 4000 wtppm or less. [8] In the manufacturing method according to any one of the above items [1] to [7], the pressure-sensitive adhesive sheet may have a refractive index of 1.55 or more. [9] In the manufacturing method according to any one of the above items [1] to [8], the monomer component M contained in the pressure-sensitive adhesive composition may contain a (meth)acrylic monomer.

[10] In the manufacturing method according to any one of the above items [1] to [9], the monomer component M contained in the pressure-sensitive adhesive composition may include a monomer a having a double bond-containing ring.

[11] In the production method described in

[10] above, the double bond-containing ring may be an aromatic ring.

[12] In the production method according to the above

[10] or

[11] , the content of the monomer a in the monomer component M may be 50 parts by weight or more.

[13] In the manufacturing method according to any one of the above items [1] to

[12] , the pressure-sensitive adhesive composition may contain a polymer B having a weight-average molecular weight of 1,500 to 30,000.

[14] In the manufacturing method described in

[13] above, the content of the polymer B in the pressure-sensitive adhesive composition may be 55 parts by weight or less relative to 100 parts by weight of the monomer component M contained in the pressure-sensitive adhesive composition.

[15] In the manufacturing method according to any one of the above items [1] to

[14] , the pressure-sensitive adhesive composition may contain inorganic particles.

[16] In the manufacturing method described in

[15] above, the inorganic particles may contain zirconium oxide.

[17] In the manufacturing method described in

[15] or

[16] above, the content of the inorganic particles may be 40 parts by weight or more relative to a total of 100 parts by weight of the monomer component M and the inorganic particles contained in the pressure-sensitive adhesive composition.

[18] In the manufacturing method according to any one of the above items [1] to

[17] , the pressure-sensitive adhesive composition may contain an ultraviolet absorber.

[19] In the manufacturing method according to any one of the above items [1] to

[18] , the content of the solvent in the pressure-sensitive adhesive composition may be 5% by weight or less.

[20] A method for manufacturing an optical film with an adhesive sheet according to an embodiment of the present invention includes forming an optical film with an adhesive sheet by placing an optical film on the exposed surface of an adhesive sheet formed by a manufacturing method described in any one of [1] to

[19] above.

[21] In the manufacturing method according to the above item

[20] , the optical film may include at least one film selected from the group consisting of a polarizing film and a retardation film.

[22] A method for manufacturing an image display device according to an embodiment of the present invention includes bonding an optical film with an adhesive sheet formed by the manufacturing method described in

[20] or

[21] above to an image display panel to form an image display device. [Effects of the Invention]

[0008] According to an embodiment of the present invention, a method for manufacturing a pressure-sensitive adhesive sheet suitable for efficiently manufacturing a photocurable pressure-sensitive adhesive sheet can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] 1A to 1C are schematic diagrams illustrating a method for producing a pressure-sensitive adhesive sheet according to one embodiment of the present invention. [Figure 2] FIG. 1 is a schematic diagram illustrating a method for producing an optical film with a pressure-sensitive adhesive sheet according to one embodiment of the present invention. [Figure 3] FIG. 1 is a schematic diagram illustrating a method for producing an optical film with a pressure-sensitive adhesive sheet according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Terminology] In this specification, when the expression "weight" appears, it may be read as "mass," which is the commonly used SI unit for indicating weight, and vice versa.

[0011] In this specification, the expression "(meth)acrylic" means "acrylic and / or methacrylic", the expression "(meth)acrylate" means "acrylate and / or methacrylate", the expression "(meth)allyl" means "allyl and / or methallyl", and the expression "(meth)acrolein" means "acrolein and / or methacrolein".

[0012] In this specification, when the term "100 parts by weight of monomer component M" is used as a standard for the content of various components in a pressure-sensitive adhesive composition, it means the total amount of the monomer component M that is not partially polymerized and is contained in the pressure-sensitive adhesive composition, and the monomer component M that is consumed in forming a partially polymerized product that may be contained in the pressure-sensitive adhesive composition.

[0013] In this specification, when the reference is made to "100 parts by weight of the total of monomer component M and inorganic particles" as a standard for the content of various components in a pressure-sensitive adhesive composition, this refers to the total amount of non-partially polymerized monomer component M contained in the pressure-sensitive adhesive composition, monomer component M consumed in forming a partially polymerized product that may be contained in the pressure-sensitive adhesive composition, and inorganic particles.

[0014] 1. Manufacturing method of adhesive sheet 1-1. First Irradiation and Second Irradiation An example of a method for producing a pressure-sensitive adhesive sheet according to an embodiment of the present invention is shown in Figure 1. In the production method of Figure 1, active energy rays 35 are irradiated onto a coating layer 12 containing a photocurable pressure-sensitive adhesive composition A, and a pressure-sensitive adhesive sheet 1 is formed from the coating layer 12. The irradiation of the active energy rays 35 onto the coating layer 12 is carried out by a first irradiation and a second irradiation subsequent to the first irradiation. The cumulative light amount of the active energy rays 35 (35A) irradiated onto the coating layer 12 in the first irradiation is 7000 mJ / cm2. 2 The cumulative amount of the active energy rays 35 (35B) irradiated onto the coating layer 12 in the second irradiation is 1600 mJ / cm 2 That's all.

[0015] By performing the first irradiation and the second irradiation on the coating layer 12, it is possible to reduce the amount of residual monomer in the formed pressure-sensitive adhesive sheet 1, for example. Residual monomer can affect the properties and durability of the pressure-sensitive adhesive sheet 1. If this reduction is possible, it will be possible to increase the degree of freedom in control of the mass production line of the pressure-sensitive adhesive sheet 1 and to simplify or even omit the process of reducing the amount of residual monomer, which has traditionally been performed on cured pressure-sensitive adhesive sheets. These can contribute to the efficient production of the pressure-sensitive adhesive sheet 1. Furthermore, the process of reducing the amount of residual monomer usually includes a heating step, but being able to omit the heating step can contribute to the sustainable production of the pressure-sensitive adhesive sheet 1.

[0016] The cumulative amount of active energy rays 35A irradiated onto the coating layer 12 in the first irradiation is 6000 mJ / cm 2 Below, 5500mJ / cm 2 Below, 5000mJ / cm 2 Below, 4500mJ / cm 2 Below, 4400mJ / cm 2 Below, 4200mJ / cm 2 Below, 4000mJ / cm 2 Below, 3900mJ / cm 2 Below, 3700mJ / cm 2 Below, 3500mJ / cm 2 Below, 3400mJ / cm 2 Below, 3200mJ / cm 2 Below, 3000mJ / cm 2 Below, 2900mJ / cm 2 Below, 2700mJ / cm 2 Below, 2500mJ / cm 2 Below, 2400mJ / cm 2 Below, 2300mJ / cm 2 Below that, 2200mJ / cm 2 The lower limit of the integrated light amount of the active energy rays 35A may be, for example, 50 mJ / cm 2 or less. 2 or more, 100 mJ / cm 2 More than 300mJ / cm 2 More than 500mJ / cm 2 More than 800mJ / cm2 More than 1000mJ / cm 2 More than 1500mJ / cm 2 More than 2000mJ / cm 2 or more, and even 2200mJ / cm 2 According to the studies of the present inventors, the more the integrated light amount of the active energy rays 35A is reduced, the more the haze of the pressure-sensitive adhesive sheet 1 formed tends to be suppressed. Pressure-sensitive adhesive sheets 1 with reduced haze are particularly suitable for use in optical laminates and image display devices.

[0017] The illuminance of the active energy rays 35A irradiated onto the coating layer 12 in the first irradiation is, for example, 25 mW / cm 2 less than 20 mW / cm 2 Below, 15mW / cm 2 Below, 10mW / cm 2 Below, 9mW / cm 2 Below, 7mW / cm 2 Below, 5mW / cm 2 Below, 4mW / cm 2 Below 3mW / cm 2 The lower limit of the illuminance may be, for example, 1 mW / cm 2 and above 2 mW / cm 2 or more, and even 3mW / cm 2 It may be more than that.

[0018] The cumulative amount of active energy rays 35B irradiated onto the coating layer 12 in the second irradiation is 1700 mJ / cm 2 More than 1800mJ / cm 2 More than 1900mJ / cm 2 More than 2000mJ / cm 2 More than 2100mJ / cm 2 More than 2300mJ / cm 2 More than 2500mJ / cm 2 More than 2800mJ / cm 2 More than 3000mJ / cm 2 More than 3300mJ / cm 2 More than 3500mJ / cm 2 More than 3800mJ / cm 2 More than 4000mJ / cm2 More than 4300mJ / cm 2 More than 4500mJ / cm 2 More than 4800mJ / cm 2 More than 5000mJ / cm 2 More than 5300mJ / cm 2 More than 5500mJ / cm 2 More than 5800mJ / cm 2 More than 6000mJ / cm 2 More than 6300mJ / cm 2 More than 6500mJ / cm 2 More than 6800mJ / cm 2 More than 7000mJ / cm 2 More than 7100mJ / cm 2 or more, and even 7200mJ / cm 2 The upper limit of the cumulative amount of light of the active energy rays 35B is not particularly limited, and may be, for example, 10,000 mJ / cm 2 or more. 2 less than 9000mJ / cm 2 Below, 8000mJ / cm 2 Below, 7500mJ / cm 2 Below that, 7200mJ / cm 2 According to the studies of the present inventors, increasing the integrated light amount of active energy rays 35B can contribute to further reducing the amount of residual monomers in the pressure-sensitive adhesive sheet that is formed.

[0019] The illuminance of the active energy rays 35B irradiated onto the coating layer 12 in the second irradiation is, for example, 8 mW / cm 2 and above 10 mW / cm 2 More than 13mW / cm 2 More than 15mW / cm 2 More than 18mW / cm 2 More than 20mW / cm 2 More than 23mW / cm 2 More than 25mW / cm 2 More than 28mW / cm 2 More than 30mW / cm 2 More than 33mW / cm 2 More than 35mW / cm 2 More than 38mW / cm 2More than 40mW / cm 2 More than 43mW / cm 2 More than 45mW / cm 2 More than 48mW / cm 2 More than 50mW / cm 2 More than 53mW / cm 2 More than 55mW / cm 2 More than 58mW / cm 2 More than 60mW / cm 2 More than 63mW / cm 2 or more, and 65mW / cm 2 The upper limit of the illuminance may be, for example, 100 mW / cm 2 less than 90mW / cm 2 Below, 80mW / cm 2 Below, 70mW / cm 2 Below 65mW / cm 2 It may be the following:

[0020] The integrated light amount of the active energy rays 35B irradiated to the coating layer 12 in the second irradiation may be greater than the integrated light amount of the active energy rays 35A irradiated to the coating layer 12 in the first irradiation. The integrated light amount of the active energy rays 35B may be smaller than the integrated light amount of the active energy rays 35A, but in this case, the difference between the integrated light amounts of the active energy rays 35B and the coating layer 12 is 1500 mJ / cm. 2 Below, 1200mJ / cm 2 Below, 1000mJ / cm 2 Below, 700mJ / cm 2 Below, 500mJ / cm 2 Below, 300mJ / cm 2 Below that, even 200mJ / cm 2 It may be the following:

[0021] The irradiance of the active energy rays 35B may be greater than the irradiance of the active energy rays 35A. In this case, the difference between the irradiances of the active energy rays 35B and the active energy rays 35A is 5 mW / cm. 2 More than 8mW / cm 2 Over 9mW / cm 2 More than 10mW / cm 2 More than 13mW / cm 2 More than 15mW / cm2 More than 18mW / cm 2 More than 20mW / cm 2 More than 25mW / cm 2 More than 30mW / cm 2 More than 35mW / cm 2 More than 40mW / cm 2 More than 45mW / cm 2 More than 50mW / cm 2 More than 55mW / cm 2 or more, and even 60mW / cm 2 The upper limit of the difference in illuminance is, for example, 80 mW / cm 2 less than 70mW / cm 2 Below, 65mW / cm 2 Below that, 62mW / cm 2 It may be the following:

[0022] Specifically, a manufacturing method according to an embodiment of the present invention can be carried out as follows (see FIG. 1 ). First, a laminate (first laminate) 10 is prepared, which includes, in this order, a substrate sheet 11, a coating layer 12, and a release liner 13. Next, a first irradiation is performed on the first laminate 10. In the first irradiation, active energy rays 35A are irradiated onto the first laminate 10 from a light source 34A. In the example of FIG. 1 , the first irradiation is the first irradiation of active energy rays 35 performed on the first laminate 10. Next, after the first irradiation, a second irradiation is performed on the first laminate 10. In the second irradiation, active energy rays 35B are irradiated onto the first laminate 10 from a light source 34B. In the example of FIG. 1 , the second irradiation is the first irradiation of active energy rays 35 performed on the first laminate 10 after the first irradiation, and is the only irradiation of active energy rays 35. In the example of Fig. 1, no irradiation with active energy rays 35 is performed between the first irradiation and the second irradiation. Moreover, the second irradiation in the example of Fig. 1 is the final irradiation of the first laminate 10 with active energy rays 35.

[0023] In the example of FIG. 1, only the first irradiation and the second irradiation are performed on the coating layer 12 (and the first laminate 10) as irradiation with active energy rays 35. However, in the manufacturing method according to an embodiment of the present invention, the coating layer 12 (and the first laminate 10) may be further irradiated with active energy rays 35 in addition to the first and second irradiations. The further irradiation may be performed at any timing. For example, the further irradiation may be performed after the second irradiation.

[0024] Irradiation with active energy rays 35, including the first irradiation and the second irradiation, photo-cures the coating layer 12, forming the pressure-sensitive adhesive sheet 1. The formed pressure-sensitive adhesive sheet 1 is sandwiched between the base sheet 11 and the release liner 13 until the release liner 13 is peeled off, and forms part of the second laminate 17. Peeling the release liner 13 from the second laminate 17 forms a third laminate 15, which includes the base sheet 11 and the pressure-sensitive adhesive sheet 1. In the third laminate 15, one surface of the pressure-sensitive adhesive sheet 1 is exposed to the outside. An optical film can be laminated onto the exposed surface of the pressure-sensitive adhesive sheet 1, either directly or via another layer.

[0025] <1-1-a. Details of the first irradiation> Irradiation with active energy rays 35A is typically carried out from the side of base sheet 11. At this time, active energy rays 35A penetrate base sheet 11 and reach coating layer 12. However, irradiation with active energy rays 35A may also be carried out from the side of release liner 13, or from both the side of release liner 13 and base sheet 11.

[0026] Examples of the active energy rays 35A include ionizing radiation such as α rays, β rays, γ rays, neutron rays, and electron beams, as well as visible light and ultraviolet light. The active energy rays 35A are preferably visible light or ultraviolet light having a wavelength shorter than 450 nm, more preferably ultraviolet light. Hereinafter, visible light and ultraviolet light will be collectively referred to as "light."

[0027] The light may include light having a wavelength in the same region as the absorption wavelength of the photopolymerization initiator contained in the pressure-sensitive adhesive composition A. Light having a wavelength of 300 nm or less may be irradiated by filtering out short-wavelength light using a filter or the like. Filtering out short-wavelength light is suitable for suppressing deterioration of the base sheet 11 and / or release liner 13 due to the active energy rays 35A. The light source 34A for the active energy rays 35A is, for example, a light irradiation device equipped with an ultraviolet irradiation lamp. Examples of ultraviolet irradiation lamps include ultraviolet LEDs, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, microwave-excited mercury lamps, black light lamps, chemical lamps, germicidal lamps, low-pressure discharge mercury lamps, and excimer lasers. Two or more ultraviolet irradiation lamps may be combined.

[0028] The light source 34A of the active energy rays 35A may include a black light, which is particularly suitable for controlling light in low-power irradiation.

[0029] The duration of the first irradiation is, for example, 10 to 1000 seconds, and may be 60 seconds or more, 100 seconds or more, 150 seconds or more, or even 200 seconds or more. The upper limit of the duration is, for example, 800 seconds or less, and may be 600 seconds or less, 500 seconds or less, 400 seconds or less, 300 seconds or less, or even 250 seconds or less.

[0030] During the first irradiation, the temperature of the coating layer 12 is preferably maintained at, for example, 50°C or lower, and more preferably at 10°C to 30°C.

[0031] The first irradiation may be carried out in an atmosphere with a reduced oxygen concentration compared to the atmosphere (oxygen concentration 20.9 vol%), or may be carried out in an atmosphere with an oxygen concentration of 20 vol% or less, 10 vol% or less, 1 vol% or less, 1000 volppm or less, or even 500 volppm or less.

[0032] <1-1-b. Details of the second irradiation> Irradiation with active energy rays 35B is typically carried out from the side of base sheet 11. At this time, active energy rays 35B penetrate base sheet 11 and reach coating layer 12. However, irradiation with active energy rays 35B may also be carried out from the side of release liner 13, or from both the side of release liner 13 and base sheet 11.

[0033] In the first laminate 10, the side on which the first irradiation is carried out and the side on which the second irradiation is carried out may be the same or different.

[0034] Examples of active energy rays 35B are the same as the examples of active energy rays 35A. Active energy rays 35B may be the same as or different from active energy rays 35A.

[0035] Examples of the light source 34B for the active energy rays 35B are the same as the examples of the light source 34A for the active energy rays 35A. The light source 34B may be the same as or different from the light source 34A. The light source 35B may include a metal halide lamp. Metal halide lamps are particularly suitable for controlling light in high-power irradiation.

[0036] In an embodiment according to the present invention, the light source 34A of the active energy rays 35A may include a black light, and the light source 34B of the active energy rays 35B may include a metal halide lamp.

[0037] The time for the second irradiation is, for example, 10 to 1000 seconds, and may be 60 seconds or more, 100 seconds or more, 150 seconds or more, or even 200 seconds or more. The upper limit of the time is, for example, 800 seconds or less, and may be 600 seconds or less, 500 seconds or less, 400 seconds or less, 300 seconds or less, or even 250 seconds or less.

[0038] The temperature of the coating layer 12 during the second irradiation and the atmosphere during the second irradiation may be the same as those described above for the first irradiation.

[0039] When the second irradiation is performed after the first irradiation, the second irradiation is preferably performed within 3 minutes after the end of the first irradiation, more preferably within 2 minutes, 1 minute, and 30 seconds. The second irradiation may be performed immediately after the end of the first irradiation.

[0040] <1-1-c.Common matters> An example of the substrate of the release liner 13 (hereinafter referred to as "liner substrate") is a resin film. Examples of resins that can be contained in the liner substrate include polyesters such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyethersulfone, polycarbonate, polyamide, polyimide, polyolefin, (meth)acrylic resins, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide. The resin is preferably a polyester such as polyethylene terephthalate.

[0041] The release liner 13 may include a layer other than the liner substrate. The release liner 13 may include a release layer. The release liner 13 includes, for example, a liner substrate and a release layer formed on one surface of the liner substrate. This release liner 13 can be used so that the release layer faces the coating layer 12. The release layer is typically a cured layer of a release agent composition containing a release agent. Various release agents can be used as the release agent, such as silicone-based release agents, fluorine-based release agents, long-chain alkyl-based release agents, fatty acid amide-based release agents, and silica powder.

[0042] The release liner 13 may be in the form of a sheet or a continuous piece.

[0043] An example of the base sheet 11 is a resin film. Examples of the resin contained in the base sheet 11 are the same as the examples of the resin that can be contained in the liner base material.

[0044] The thickness of the base sheet 11 is, for example, 10 to 200 μm, and may be 25 to 150 μm.

[0045] The base sheet 11 may have a release layer on the surface on the side of the coating layer 12. Examples of the release layer that may be provided on the base sheet 11 are the same as the examples of the release layer that may be provided on the release liner 13. Both the release liner 13 and the base sheet 11 may have a release layer.

[0046] For the base sheet 11, a sheet having a greater peel strength from the adhesive sheet 1 than the release liner 13 can usually be selected.

[0047] The base sheet 11 may be in the form of a sheet or a continuous sheet.

[0048] The first laminate 10 can be formed, for example, by forming a coating layer 12 on a base sheet 11 (or a release liner 13) and then placing the release liner 13 (or base sheet 11) on the formed coating layer 12. Alternatively, the first laminate 10 may be formed by applying the photocurable composition in a poured manner into the space between the base sheet 11 and the release liner 13, which are held at a predetermined distance so that their main surfaces face each other.

[0049] The coating layer 12 can be formed by various coating methods such as roll coating, kiss roll coating, gravure coating, reverse coating, roll brush, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and die coating.

[0050] The thickness of coating layer 12 can be adjusted depending on the desired thickness of pressure-sensitive adhesive sheet 1, and may be, for example, 500 μm or less, 250 μm or less, 150 μm or less, 100 μm or less, 50 μm or less, 30 μm or less, 25 μm or less, or even 20 μm or less. The lower limit of the thickness of coating layer 12 is, for example, 2 μm or more, and may be 5 μm or more.

[0051] The first laminate 10 may include a long base sheet 11, a long coating layer 12, and a long release liner 13, in other words, it may be long. The long first laminate 10 can be obtained, for example, by forming the coating layer 12 between the base sheet 11 and the release liner 13 while conveying them after they have been unwound from a roll.

[0052] The manufacturing method according to the embodiment of the present invention may not substantially include a step of heating the coating layer 12, and may not substantially include a step of heating the coating layer 12 between the first irradiation and the second irradiation. Furthermore, the manufacturing method according to the embodiment of the present invention may not substantially include a step of heating the pressure-sensitive adhesive sheet 1 formed through the second irradiation. The ability to omit the heating step can contribute to efficient manufacturing of the pressure-sensitive adhesive sheet 1. Note that "not substantially including a heating step" means that the object is not heated using a heating device.

[0053] The manufacturing method according to the embodiment of the present invention may not include the step of subjecting the pressure-sensitive adhesive sheet 1 formed through the second irradiation to a corona treatment and / or plasma treatment. Corona treatment and plasma treatment are sometimes performed to reduce the amount of residual monomer in the pressure-sensitive adhesive sheet. The ability to omit the corona treatment and plasma treatment steps can contribute to the efficient manufacture of the pressure-sensitive adhesive sheet 1.

[0054] In the manufacturing method according to an embodiment of the present invention, a pressure-sensitive adhesive sheet 1 having a residual monomer amount of 4000 wtppm or less may be formed. The residual monomer amount in the pressure-sensitive adhesive sheet 1 to be formed may be 3750 wtppm or less, 3500 wtppm or less, 3250 wtppm or less, 3000 wtppm or less, 2750 wtppm or less, 2500 wtppm or less, 2400 wtppm or less, 2300 wtppm or less, 2200 wtppm or less, 2100 wtppm or less, 2000 wtppm or less, 1900 wtppm or less, 1800 wtppm or less, 1700 wtppm or less. The lower limit of the residual monomer amount may be, for example, 10 wtppm or more, 50 wtppm or more, or even 100 wtppm or more.

[0055] In the manufacturing method according to an embodiment of the present invention, a pressure-sensitive adhesive sheet 1 having a refractive index of 1.55 or higher may be formed. The refractive index of the pressure-sensitive adhesive sheet 1 formed may be 1.56 or higher, 1.57 or higher, 1.58 or higher, 1.59 or higher, 1.60 or higher, 1.61 or higher, 1.615 or higher, 1.62 or higher, 1.63 or higher, 1.64 or higher, or even 1.65 or higher. The upper limit of the refractive index is, for example, 1.80 or lower, and may be 1.79 or lower, 1.78 or lower, 1.77 or lower, 1.76 or lower, 1.75 or lower, 1.74 or lower, 1.73 or lower, 1.72 or lower, 1.71 or lower, 1.70 or lower, 1.69 or lower, 1.68 or lower, 1.67 or lower, or even 1.66 or lower. In some cases, the upper limit of the refractive index may be 1.65 or lower, 1.64 or lower, or even 1.63 or lower. A preferred example of the refractive index is 1.63 to 1.66. Another preferred example of the refractive index is 1.60 to 1.63. The optical laminate may include an optical substrate having a high refractive index. Using a high refractive index pressure-sensitive adhesive sheet 1 to bond a high refractive index optical substrate is advantageous in reducing reflected light at the interface between the optical substrate and the pressure-sensitive adhesive sheet.

[0056] In this specification, the refractive index of the adhesive sheet 1 refers to the refractive index of the surface of the adhesive sheet 1. The refractive index of the adhesive sheet 1 can be measured using a prism coupler under conditions of a measurement temperature of 25°C and a measurement wavelength of 594 nm. For adhesive sheets 1 with a thickness of less than 20 μm, measurement in the optical propagation mode is generally suitable. For adhesive sheets 1 with a thickness of 20 μm or more, measurement in the critical angle mode is generally suitable. A commercially available measuring device can be used as the prism coupler, for example, a Model 2010 / M prism coupler manufactured by Metricon or an equivalent can be used.

[0057] The gel fraction of the pressure-sensitive adhesive sheet 1 to be formed is, for example, 50% or more, and may be 75% or more, 80% or more, 85% or more, or even 90% or more.

[0058] The haze of the pressure-sensitive adhesive sheet 1 to be formed is, for example, 5.0% or less, and may be 4.0% or less, 3.0% or less, 2.5% or less, 2.2% or less, 2.0% or less, 1.9% or less, 1.8% or less, 1.7% or less, 1.6% or less, 1.5% or less, 1.4% or less, 1.3% or less, 1.2% or less, 1.1% or less, 1.0% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, or even 0.5% or less. The lower limit of the haze is not particularly limited and may be 0.1% or more. A low-haze pressure-sensitive adhesive sheet 1 is particularly suitable for use in optical laminates.

[0059] In this specification, haze refers to the ratio of diffuse transmitted light to total transmitted light when visible light is irradiated onto the pressure-sensitive adhesive sheet 1, which is the object to be measured. Haze can be calculated using the following formula: In the following formula, Th is haze (%), Td is scattered light transmittance, and Tt is total light transmittance. Th(%)=Td / Tt×100

[0060] The chromaticity of the adhesive sheet 1 to be formed is CIE1976 L defined in Japanese Industrial Standard (JIS) Z8781-4:2013. * ,a * ,b * Color space chromaticity b* The absolute value of chromaticity b may be 2.0 or less. * The absolute value of chromaticity b may be 1.7 or less, 1.5 or less, 1.2 or less, 1.1 or less, 1.0 or less, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, or even 0.5 or less. * The lower limit of the absolute value of chromaticity b of the pressure-sensitive adhesive sheet 1 is, for example, 0 or more, and may be 0.1 or more. * can be evaluated using a commercially available colorimeter capable of measurements in accordance with JIS Z8781-4:2013.

[0061] The thickness of the pressure-sensitive adhesive sheet 1 to be formed is, for example, 500 μm or less, and may be 250 μm or less, 150 μm or less, 100 μm or less, 50 μm or less, 30 μm or less, 25 μm or less, or even 20 μm or less. The lower limit of the thickness is, for example, 2 μm or more, and may be 5 μm or more. In some cases, the lower limit of the thickness may be 20 μm or more, or may be 30 μm or more. A preferred example of the thickness is 2 to 30 μm. Another preferred example of the thickness is 30 to 100 μm.

[0062] The pressure-sensitive adhesive sheet 1 produced by the production method according to the embodiment of the present invention is particularly suitable for use in optical laminates and image display devices. In other words, the pressure-sensitive adhesive sheet 1 to be formed may be an optical pressure-sensitive adhesive sheet.

[0063] <1-2. Pressure-sensitive adhesive composition A> The pressure-sensitive adhesive composition A is a photocurable pressure-sensitive adhesive composition that forms a pressure-sensitive adhesive sheet by irradiation with active energy rays. The photocurable type is particularly preferable in terms of environmental protection and sustainability, since it can reduce the amount of energy required to form a pressure-sensitive adhesive sheet compared to a thermosetting type that forms a pressure-sensitive adhesive sheet mainly by using heat.

[0064] <1-2-a. Monomer component M> The pressure-sensitive adhesive composition A usually contains a monomer component M. A part of the monomer component M may be in the form of a partial polymer.

[0065] [1-2-a1. (Meth)acrylic monomer] Monomer component M may contain a (meth)acrylic monomer or an acrylic monomer. The content of the (meth)acrylic monomer in monomer component M is, for example, 50% by weight or more, and may be 60% by weight or more, 70% by weight or more, 75% by weight or more, 80% by weight or more, 85% by weight or more, 90% by weight or more, 92% by weight or more, 94% by weight or more, 95% by weight or more, 96% by weight or more, 97% by weight or more, or even 98% by weight or more. Monomer component M may contain only (meth)acrylic monomers as monomers.

[0066] [1-2-a2. Monomer a having a double bond-containing ring] The monomer component M may contain a monomer a having a double bond-containing ring. Monomer a can contribute to improving the refractive index of the pressure-sensitive adhesive sheet 1 to be formed. In this specification, a double bond-containing ring refers to a ring in which at least one of the bonds constituting the ring is a double bond. Examples of double bonds include carbon-carbon double bonds, carbon-heteroatom double bonds, and heteroatom-heteroatom double bonds. Examples of heteroatoms include nitrogen, sulfur, and oxygen.

[0067] The number of double bonds in the double bond-containing ring is not particularly limited and may be, for example, 1 to 10, or 2 to 5. When the double bond-containing ring contains two or more double bonds, these double bonds may be conjugated or non-conjugated. The double bond-containing ring is preferably an aromatic ring.

[0068] The double bond-containing ring may be a carbocyclic ring. Examples of the carbocyclic ring include a benzene ring (which may be a benzene ring constituting a part of a biphenyl structure or a fluorene structure), a naphthalene ring, an indene ring, an azulene ring, an anthracene ring, and a phenanthrene ring. The double bond-containing ring may be a heterocyclic ring. Examples of the heterocyclic ring include a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, an oxazole ring, an isoxazole ring, a thiazole ring, and a thiophene ring. Examples of heteroatoms that may be contained in the heterocyclic ring as ring-constituting atoms include at least one selected from the group consisting of nitrogen, sulfur, and oxygen. The heteroatom may be either or both nitrogen and sulfur. The double bond-containing ring may be a fused ring. An example of the monomer a has a structure in which one or more carbocyclic rings and one or more heterocyclic rings are fused, such as a dinaphthothiophene structure.

[0069] The double bond-containing ring may have one or more substituents (excluding ethylenically unsaturated groups, which will be described later) on the ring-constituting atoms, or may have no substituents. Examples of the substituents include alkyl groups, alkoxy groups, aryloxy groups, hydroxyl groups, halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, etc.), hydroxyalkyl groups, hydroxyalkyloxy groups, and glycidyloxy groups. However, the substituents are not limited to the above examples. The substituents may contain carbon atoms, and in such cases, the number of carbon atoms contained in the substituent is, for example, 1 to 4, 1 to 3, or even 1 to 2. One example of the double bond-containing ring has no substituents on the ring-constituting atoms. Another example of the double bond-containing ring has one or more substituents selected from the group consisting of alkyl groups, alkoxy groups, and halogen atoms (e.g., bromine atoms) on the ring-constituting atoms.

[0070] In the monomer a, the number of double bond-containing rings contained in one molecule is, for example, 1, and may be 2 or more. The upper limit of the number of double bond-containing rings is not particularly limited and is, for example, 16 or less. The upper limit may be 12 or less, 8 or less, 6 or less, 5 or less, 4 or less, 3 or less, or even 2 or less.

[0071] In the monomer a, the double bond-containing ring is preferably located in a side chain. In other words, the monomer a preferably has at least one double bond-containing ring and at least one ethylenically unsaturated group in one molecule. As the monomer a, a compound having one ethylenically unsaturated group in one molecule (in other words, a monofunctional monomer) is preferably used.

[0072] Examples of the ethylenically unsaturated group are a (meth)acryloyl group, a vinyl group, and a (meth)allyl group. From the viewpoint of polymerization reactivity, a (meth)acryloyl group is preferred, and from the viewpoint of flexibility and adhesiveness, an acryloyl group is more preferred. In other words, monomer a preferably contains a (meth)acrylic monomer having a double bond-containing ring, and more preferably contains an acrylic monomer having a double bond-containing ring. Examples of the (meth)acrylic monomer having a double bond-containing ring include aromatic ring-containing (meth)acrylates. Specific examples of aromatic ring-containing (meth)acrylates will be described later.

[0073] The double bond-containing ring and the ethylenically unsaturated group may be bonded directly or via a linking group. Examples of the linking group include one or more selected from the group consisting of alkylene groups, oxyalkylene groups, poly(oxyalkylene) groups, phenyl groups, alkylphenyl groups, alkoxyphenyl groups, groups in which one or more hydrogen atoms in these groups have been substituted with hydroxyl groups (e.g., hydroxyalkylene groups), oxy groups (-O-), and thiooxy groups (-S-). In one example of Monomer A, the double bond-containing ring and the ethylenically unsaturated group are bonded directly. In another example of Monomer A, the double bond-containing ring and the ethylenically unsaturated group are bonded via a linking group selected from the group consisting of alkylene groups, oxyalkylene groups, and poly(oxyalkylene) groups. The number of carbon atoms in the alkylene group and oxyalkylene group that can be included in the linking group is, for example, 1 to 4, and may be 1 to 3, or even 1 to 2. The number of repeating oxyalkylene units in the poly(oxyalkylene) group that can be contained in the linking group is, for example, 1 to 8, and may be 1 to 6, 1 to 4, 1 to 3, 2 to 3, or even 1 to 2, 2, or 1.

[0074] Specific examples of the monomer a include aromatic ring-containing (meth)acrylates and aromatic ring-containing vinyl compounds. The aromatic ring-containing (meth)acrylates and aromatic ring-containing vinyl compounds may be used alone or in combination of two or more.

[0075] Monomer a may contain two or more aromatic rings (preferably carbon rings) in one molecule. A monomer having two or more aromatic rings and at least one ethylenically unsaturated group in one molecule (aromatic ring-containing monomer) can particularly contribute to increasing the refractive index of the pressure-sensitive adhesive sheet.

[0076] Examples of the aromatic ring-containing monomer include a monomer having a structure in which two or more non-condensed aromatic rings are bonded via a linking group, a monomer having a structure in which two or more non-condensed aromatic rings are directly bonded, a monomer having a condensed ring, a monomer having a fluorene structure, a monomer having a dinaphthothiophene structure, and a monomer having a dibenzothiophene structure.Among these, a monomer having a structure in which two or more non-condensed aromatic rings are bonded via a linking group (for example, phenoxybenzyl (meth)acrylate described later) is preferably used.

[0077] The linking group may contain atoms such as P, Ge, Te, Se, N, S, and Si, and these atoms may be bonded to an oxygen atom. However, the linking group does not have to contain any of the above atoms. Examples of linking groups include an oxy group (-O-), a thiooxy group (-S-), an oxyalkylene group (e.g., -O-(CH2)), and the like. n -; n is 1 to 3, preferably 1), a thiooxyalkylene group (e.g., -S-(CH2) n -; n is 1 to 3, preferably 1), a straight-chain alkylene group (-(CH2) n -; n is 1 to 6, preferably 1 to 3), and the above-mentioned oxyalkylene group, the above-mentioned thiooxyalkylene group, and the above-mentioned straight-chain alkylene group in which the alkylene group is partially or completely halogenated. The linking group may contain one or more groups selected from the group consisting of an oxy group, a thiooxy group, an oxyalkylene group, and a straight-chain alkylene group. Specific examples of monomers having a structure in which two or more non-condensed aromatic rings are bonded via a linking group include phenoxybenzyl (meth)acrylate, thiophenoxybenzyl (meth)acrylate, and benzyl benzyl (meth)acrylate.

[0078] Examples of monomers having a structure in which two or more non-fused aromatic rings are directly bonded include biphenyl structure-containing (meth)acrylates, triphenyl structure-containing (meth)acrylates, and vinyl group-containing biphenyls. Specific examples include o-phenylphenol (meth)acrylate, biphenyl (meth)acrylate, and biphenylmethyl (meth)acrylate.

[0079] Examples of monomers having a condensed ring include naphthalene ring-containing (meth)acrylates, anthracene ring-containing (meth)acrylates, vinyl group-containing naphthalenes, and vinyl group-containing anthracenes. Specific examples include 1-naphthylmethyl (meth)acrylate (also known as 1-naphthalenemethyl (meth)acrylate), hydroxyethylated β-naphthol acrylate, 2-naphthoethyl (meth)acrylate, 2-naphthoxyethyl acrylate, and 2-(4-methoxy-1-naphthoxy)ethyl (meth)acrylate.

[0080] Examples of monomers having a fluorene structure include 9,9-bis(4-hydroxyphenyl)fluorene(meth)acrylate and 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene(meth)acrylate. Note that, since monomers having a fluorene structure have a structure in which two benzene rings are directly bonded, they are included in the concept of monomers having a structure in which two or more non-fused aromatic rings are directly bonded.

[0081] Examples of the monomer having a dinaphthothiophene structure are (meth)acryloyl group-containing dinaphthothiophene, vinyl group-containing dinaphthothiophene, and (meth)allyl group-containing dinaphthothiophene. Specific examples include (meth)acryloyloxymethyl dinaphthothiophene (e.g., a compound having a structure in which a CHCH(R)C(O)OCH group is bonded to the 5th or 6th position of the dinaphthothiophene ring; R is a hydrogen atom or a methyl group), (meth)acryloyloxyethyl dinaphthothiophene (e.g., a compound having a structure in which a CHCH(R)C(O)OCH(CH) group or a CHCH(R)C(O)OCHCH group is bonded to the 5th or 6th position of the dinaphthothiophene ring; R is a hydrogen atom or a methyl group), vinyl dinaphthothiophene (e.g., a compound having a structure in which a vinyl group is bonded to the 5th or 6th position of the naphthothiophene ring), and (meth)allyloxy dinaphthothiophene. Incidentally, a monomer having a dinaphthothiophene structure is included in the concept of a monomer having a fused ring because it has a naphthalene structure and also has a structure in which a thiophene ring and two naphthalene structures are fused together.

[0082] Examples of monomers having a dibenzothiophene structure include (meth)acryloyl group-containing dibenzothiophenes and vinyl group-containing dibenzothiophenes. Note that, since monomers having a dibenzothiophene structure have a structure in which a thiophene ring and two benzene rings are fused, they are included in the concept of monomers having fused rings. Neither the dinaphthothiophene structure nor the dibenzothiophene structure corresponds to a structure in which two or more non-fused aromatic rings are directly bonded.

[0083] Monomer a may be a monomer having one aromatic ring (preferably a carbon ring) and at least one ethylenically unsaturated group in one molecule (aromatic ring-single-containing monomer).

[0084] Examples of aromatic ring-containing monomers include carbon aromatic ring-containing (meth)acrylates such as benzyl (meth)acrylate, methoxybenzyl (meth)acrylate, phenyl (meth)acrylate, ethoxylated phenol (meth)acrylate, phenoxypropyl (meth)acrylate, phenoxybutyl (meth)acrylate, cresyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, and chlorobenzyl (meth)acrylate; 2-(4,6-dibromo-2-s-butylphenoxy)ethyl (meth)acrylate, 2-(4,6-dibromo-2-isopropylphenoxy)ethyl (meth)acrylate, and 6-(4 Bromine-substituted aromatic ring-containing (meth)acrylates such as 2,6-dibromo-4-nonylphenyl acrylate, 2,6-dibromo-4-dodecylphenyl acrylate; carbon-containing aromatic ring-containing vinyl compounds such as styrene, α-methylstyrene, vinyltoluene, and tert-butylstyrene; and compounds having a vinyl substituent on a heteroaromatic ring such as N-vinylpyridine, N-vinylpyrimidine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, and N-vinyloxazole.

[0085] Monomer a may have a structure in which an oxyethylene chain is interposed between the ethylenically unsaturated group and the double bond-containing ring in the various monomers a described above. Monomers having such a structure can be understood as ethoxylated products of the original monomers. The number of repeating oxyethylene units (-CHCHO-) in the oxyethylene chain is, for example, 1 to 8, and may be 1 to 6, 1 to 4, 1 to 3, or even 1 to 2, or even 1. Examples of monomer a that is an ethoxylated product include ethoxylated o-phenylphenol (meth)acrylate, ethoxylated nonylphenol (meth)acrylate, ethoxylated cresol (meth)acrylate, phenoxyethyl (meth)acrylate, and phenoxydiethylene glycol (meth)acrylate.

[0086] Monomer a may include a high refractive index monomer. In this specification, the high refractive index monomer refers to a monomer having a refractive index of 1.51 or more, 1.53 or more, 1.55 or more, 1.56 or more, 1.57 or more, 1.58 or more, 1.59 or more, 1.60 or more, 1.61 or more, 1.62 or more, 1.63 or more, 1.64 or more, 1.65 or more, 1.66 or more, 1.67 or more, 1.68 or more, or even 1.69 or more. The upper limit of the refractive index of the high refractive index monomer is not particularly limited, and may be, for example, 3.00 or less, 2.50 or less, 2.00 or less, 1.90 or less, 1.80 or less, or even 1.70 or less. The high refractive index monomer may be used alone or in combination of two or more.

[0087] The refractive index of the monomer can be measured using an Abbe refractometer at a wavelength of 589 nm and a temperature of 25°C. The Abbe refractometer may be a DR-M4 model manufactured by ATAGO or an equivalent (e.g., DR-M2 model). If the nominal value of the refractive index at 25°C is provided by the monomer manufacturer, this nominal value can be used as the refractive index.

[0088] Examples of high refractive index monomers are phenoxybenzyl acrylate (refractive index 1.566), 1-naphthylmethyl acrylate (refractive index 1.595), ethoxylated o-phenylphenol acrylate (refractive index 1.578 when the number of repeating oxyethylene units is 1), benzyl acrylate (refractive index 1.519), phenoxyethyl acrylate (refractive index 1.517), and phenoxydiethylene glycol acrylate (refractive index 1.510). ), 6-acryloyloxymethyldinaphthothiophene (refractive index 1.75), 6-methacryloyloxymethyldinaphthothiophene (refractive index 1.726), 5-acryloyloxyethyldinaphthothiophene (refractive index 1.786), 6-acryloyloxyethyldinaphthothiophene (refractive index 1.722), 6-vinyldinaphthothiophene (refractive index 1.802), and 5-vinyldinaphthothiophene (refractive index 1.793). However, the high refractive index monomer is not limited to the above examples. It is preferable that monomer a contains phenoxybenzyl acrylate as a high refractive index monomer.

[0089] The content of monomer a in monomer component M is, for example, 30% by weight or more, and may be 50% by weight or more, 60% by weight or more, 65% by weight or more, 70% by weight or more, more than 70% by weight, 75% by weight or more, 80% by weight or more, 85% by weight or more, 87% by weight or more, 90% by weight or more, 91% by weight or more, 92% by weight or more, 93% by weight or more, 94% by weight or more, 95% by weight or more, 96% by weight or more, 97% by weight or more, 98% by weight or more, or even 99% by weight or more. The upper limit of the content is, for example, 100% by weight, and may be 98% by weight or less, 97% by weight or less, 96% by weight or less, 95% by weight or less, 93% by weight or less, 90% by weight or less, less than 90% by weight, 85% by weight or less, 80% by weight or less, 75% by weight or less, 70% by weight or less, 60% by weight or less, 50% by weight or less, 25% by weight or less, 10% by weight or less, or even 5% by weight or less.

[0090] When the pressure-sensitive adhesive composition A contains inorganic particles described below, the content of monomer a relative to 100 parts by weight of the total of monomer component M and inorganic particles (more specifically, a mixture of inorganic particles and a dispersant) may be 10 parts by weight or more, 20 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 36 parts by weight or more, 37 parts by weight or more, 38 parts by weight or more, 39 parts by weight or more, 40 parts by weight or more, 41 parts by weight or more, 42 parts by weight or more, 43 parts by weight or more, 44 parts by weight or more, 45 parts by weight or more, 46 parts by weight or more, 47 parts by weight or more, 48 parts by weight or more, 49 parts by weight or more, 50 parts by weight or more, 51 parts by weight or more, 52 parts by weight or more, 53 parts by weight or more, 54 parts by weight or more, 55 parts by weight or more, 56 parts by weight or more, 57 parts by weight or more, 58 parts by weight or more, or even 59 parts by weight or more. The upper limit of the content may be 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, or even 60 parts by weight or less. The content may be 40 to 60 parts by weight.

[0091] [1-2-a3. Other Monomers] Monomer component M may contain a monomer d other than monomer a. An example of monomer d is a hydroxyl group-containing monomer. The hydroxyl group-containing monomer has at least one hydroxyl group and at least one ethylenically unsaturated group in one molecule. Monomer component M may contain one or more hydroxyl group-containing monomers.

[0092] Examples of the ethylenically unsaturated group are the same as those mentioned above in the description of monomer A. The hydroxyl group-containing monomer may be a (meth)acrylic monomer.

[0093] Examples of the hydroxyl group-containing monomer are 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)-methyl acrylate. The hydroxyl group-containing monomer is preferably 4-hydroxybutyl (meth)acrylate.

[0094] The content of the hydroxyl group-containing monomer in the monomer component M is, for example, 25% by weight or less, and may be 20% by weight or less, 15% by weight or less, 12% by weight or less, 10% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, 5% by weight or less, 4% by weight or less, 3% by weight or less, or even 2% by weight or less. The lower limit of the content is, for example, 0.01% by weight or more, 0.1% by weight or more, 0.5% by weight or more, or even 1% by weight or more. The monomer component M may not contain a hydroxyl group-containing monomer.

[0095] Another example of monomer d is a (meth)acrylic acid alkyl ester having an alkyl group of 1 to 20 carbon atoms on the side chain. The number of carbon atoms in the alkyl group may be 7 or less, 6 or less, 5 or less, or even 4 or less. The alkyl group may be linear or branched. Examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate (lauryl (meth)acrylate), n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, and octadecyl (meth)acrylate. The (meth)acrylic acid alkyl ester may be n-butyl (meth)acrylate.

[0096] The content of (meth)acrylic acid alkyl ester in the monomer component M is, for example, 25% by weight or less, and may be 20% by weight or less, 15% by weight or less, 10% by weight or less, 7% by weight or less, 5% by weight or less, or even 4% by weight or less. The lower limit of the content may be, for example, 0.01% by weight or more, 0.1% by weight or more, 0.5% by weight or more, or even 1% by weight or more. The monomer component M may not contain a (meth)acrylic acid alkyl ester.

[0097] Another example of the monomer d is an aliphatic ring-containing monomer. The aliphatic ring-containing monomer has at least one aliphatic ring and at least one ethylenically unsaturated group in one molecule. The aliphatic ring-containing monomer may be used alone or in combination of two or more kinds.

[0098] Examples of the ethylenically unsaturated group are the same as those mentioned above in the description of monomer A. The aliphatic ring-containing monomer may be a (meth)acrylic monomer.

[0099] Examples of the aliphatic ring-containing monomer include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, cyclooctyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, and adamantyl (meth)acrylate.

[0100] The content of the alicyclic monomer in the monomer component M is, for example, 25% by weight or less, and may be 20% by weight or less, 15% by weight or less, 10% by weight or less, 7% by weight or less, 5% by weight or less, or even 4% by weight or less. The lower limit of the content may be, for example, 0.01% by weight or more, 0.1% by weight or more, 0.5% by weight or more, or even 1% by weight or more. The monomer component M may not contain an alicyclic monomer.

[0101] Another example of the monomer d is a carboxyl group-containing monomer. The carboxyl group-containing monomer that may be contained in the monomer component M has at least one carboxyl group and at least one ethylenically unsaturated group in one molecule. The monomer component M may contain one or more types of carboxyl group-containing monomers.

[0102] Examples of the ethylenically unsaturated group are the same as those mentioned above in the description of monomer A. The carboxyl group-containing monomer may be a (meth)acrylic monomer.

[0103] Examples of carboxyl group-containing monomers are (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid.

[0104] The content of the carboxyl group-containing monomer in the monomer component M is, for example, 10% by weight or less, and may be 7% by weight or less, 5% by weight or less, 3% by weight or less, or even 1% by weight or less. The lower limit of the content may be, for example, 0.01% by weight or more, 0.1% by weight or more, 0.5% by weight or more, or even 1% by weight or more. It is preferable that the monomer component M does not contain a carboxyl group-containing monomer.

[0105] Another example of monomer d is an ether group-containing monomer. The ether group-containing monomer that may be contained in monomer component M has at least one ether group and at least one ethylenically unsaturated group in one molecule. Monomer component M may contain one or more types of ether group-containing monomers.

[0106] The ether group of the ether group-containing monomer is usually contained in a portion that becomes a side chain after polymerization. The side chain may be linear or branched. The ether group-containing monomer may have an oxyalkylene group, and the number of oxyalkylene groups in one molecule may be, for example, 1 to 30, 1 to 12, or even 1 to 5.

[0107] Examples of the oxyalkylene group include an oxymethylene group, an oxyethylene group, and an oxypropylene group. The ether group-containing monomer preferably has an oxyethylene group. The ether group-containing monomer having an oxyethylene group is represented, for example, by the following formula (1): [ka]

[0108] R in Equation (1) 1 is a hydrogen atom or a methyl group. 2 is a hydrocarbon group. In a preferred example, the hydrocarbon group is an alkyl group. The alkyl group may be linear or branched. Examples of the alkyl group are a methyl group and an ethyl group. In another example, the hydrocarbon group contains a carbon ring. Examples of the carbon ring are the same as those mentioned above in the description of the double bond-containing ring. An example of a hydrocarbon group containing a carbon ring is a phenyl group.

[0109] In formula (1), n ​​is an integer of 1 to 30, preferably an integer of 1 to 12, and may be an integer of 1 to 5.

[0110] Examples of ether group-containing monomers are 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, and methoxydipropylene glycol (meth)acrylate.

[0111] The content of the ether group-containing monomer in the monomer component M is, for example, 0.1% by weight or more, and may be 0.2% by weight or more, 0.3% by weight or more, 0.4% by weight or more, 0.5% by weight or more, 1% by weight or more, 2% by weight or more, 3% by weight or more, 4% by weight or more, or even 5% by weight or more. The upper limit of the content is, for example, 30% by weight or less, and may be 25% by weight or less, 20% by weight or less, 15% by weight or less, 14% by weight or less, 13% by weight or less, 12% by weight or less, 11% by weight or less, or even 10% by weight or less. The content is preferably 1 to 20% by weight.

[0112] When the pressure-sensitive adhesive composition A contains inorganic particles described below, the content of monomer d relative to 100 parts by weight of the total of monomer component M and inorganic particles (specifically, a mixture of inorganic particles and a dispersant) may be 30 parts by weight or less, 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, 8 parts by weight or less, 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, or even 1.5 parts by weight or less. The lower limit of the content may be 0.01 parts by weight or more, 0.1 parts by weight or more, 0.5 parts by weight or more, or even 1 part by weight or more. Monomer component M may not contain monomer d.

[0113] When the pressure-sensitive adhesive composition A contains inorganic particles described below, the content of the monomer component M relative to 100 parts by weight of the total of the monomer component M and the inorganic particles (more specifically, a mixture of the inorganic particles and the dispersant) may be 10 parts by weight or more, 20 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 36 parts by weight or more, 37 parts by weight or more, 38 parts by weight or more, 39 parts by weight or more, 40 parts by weight or more, 41 parts by weight or more, 42 parts by weight or more, 43 parts by weight or more, 44 parts by weight or more, 45 parts by weight or more, 46 parts by weight or more, 47 parts by weight or more, 48 parts by weight or more, 49 parts by weight or more, 50 parts by weight or more, 51 parts by weight or more, 52 parts by weight or more, 53 parts by weight or more, 54 parts by weight or more, 55 parts by weight or more, 56 parts by weight or more, 57 parts by weight or more, 58 parts by weight or more, 59 parts by weight or more, or even 60 parts by weight or more. The upper limit of the content may be 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, or even 60 parts by weight or less. The content may be 40 to 60 parts by weight.

[0114] The pressure-sensitive adhesive sheet 1 thus formed contains a polymer having structural units formed by polymerization of the monomers contained in the monomer component M.

[0115] The polymerization rate of the monomer component M in the pressure-sensitive adhesive sheet 1 to be formed is preferably 90% or more, and may be 95% or more, 98% or more, or even 99% or more.

[0116] <1-2-b. Partially polymerized product> The pressure-sensitive adhesive composition A may contain a partial polymer of the monomer component M. The partial polymer may be either a homopolymer or a copolymer. The partial polymer can contribute to the stable formation of a coating layer, which will be described later, by appropriately increasing the viscosity of the pressure-sensitive adhesive composition A. Note that the pressure-sensitive adhesive composition A does not necessarily contain a partial polymer.

[0117] The weight-average molecular weight of the partial polymer may be, for example, greater than 30,000, 50,000 or more, 100,000 or more, 500,000 or more, or even 1,000,000 or more. The upper limit of the weight-average molecular weight is not particularly limited, and may be, for example, 3,000,000 or less, or 2,000,000 or less. The weight-average molecular weight is determined by measuring using GPC (gel permeation chromatography) and calculating the value in terms of polystyrene.

[0118] <1-2-c. Photopolymerization initiator> The pressure-sensitive adhesive composition A usually contains a photopolymerization initiator. The photopolymerization initiator may be a photoradical generator that generates radicals when exposed to visible light and / or ultraviolet light with a wavelength shorter than 450 nm.

[0119] Examples of photopolymerization initiators include benzoin ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzil dimethyl ketal; substituted benzoin ethers such as anisole methyl ether; substituted acetophenones such as 2,2-diethoxyacetophenone and 2,2-dimethoxy-2-phenylacetophenone; α-hydroxyalkylphenones such as 1-hydroxycyclohexyl-phenyl ketone; substituted alpha-ketols such as 2-methyl-2-hydroxypropiophenone; aromatic sulfonyl chlorides such as 2-naphthalenesulfonyl chloride; photoactive oximes such as 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime; and benzophenone compounds such as benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone. Thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and 2,4-diethylthioxanthone; 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, and 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine triazine-based compounds such as 2-piperonyl-4,6-bis(trichloromethyl)-s-triazine, 2,4-bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxy-naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, and 2,4-trichloromethyl-(4'-methoxystyryl)-6-triazine;Oxime ester compounds such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], O-(acetyl)-N-(1-phenyl-2-oxo-2-(4'-methoxy-naphthyl)ethylidene)hydroxylamine; phosphine compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; quinone compounds such as 9,10-phenanthrenequinone, camphorquinone, and ethylanthraquinone; borate compounds; carbazole compounds; imidazole compounds; and titanocene compounds. The pressure-sensitive adhesive composition A may contain one or more photopolymerization initiators.

[0120] Specific examples of the photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethan-1-one (Omnirad 651, manufactured by IGM Resins), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad 819, manufactured by IGM Resins), and 1-hydroxycyclohexyl phenyl ketone (Omnirad 184, manufactured by IGM Resins).

[0121] The content of the photopolymerization initiator in the pressure-sensitive adhesive composition A is, for example, 0.02 to 10 parts by weight, or may be 0.05 to 5 parts by weight, 0.1 to 3 parts by weight, or even 0.2 to 2 parts by weight, relative to 100 parts by weight of the monomer component M.

[0122] When the pressure-sensitive adhesive composition A contains inorganic particles described below, the content of the photopolymerization initiator relative to a total of 100 parts by weight of the monomer component M and the inorganic particles (more specifically, a mixture of the inorganic particles and the dispersant) may be 0.02 to 10 parts by weight, 0.05 to 5 parts by weight, 0.1 to 3 parts by weight, or even 0.2 to 2 parts by weight.

[0123] <1-2-d. Polymer B> The pressure-sensitive adhesive composition A may contain a polymer B having a weight-average molecular weight of 1,500 to 30,000. The polymer B may contribute to reducing the haze of the pressure-sensitive adhesive sheet 1 formed by the production method according to the embodiment of the present invention. The polymer B may also contribute to improving the adhesive strength of the pressure-sensitive adhesive sheet. The polymer B may function as a tackifier. The pressure-sensitive adhesive composition A may contain one or more types of polymer B.

[0124] The weight-average molecular weight of polymer B may be 25,000 or less, 20,000 or less, 18,000 or less, 16,000 or less, 15,000 or less, 13,000 or less, 10,000 or less, 8,000 or less, or even 6,000 or less. The lower limit of the weight-average molecular weight is 1,500 or more, 2,000 or more, 2,500 or more, 3,000 or more, 3,500 or more, or even 4,000 or more. The weight-average molecular weight may be 2,000 to 16,000, and preferably 4,000 to 16,000. The weight-average molecular weight of polymer B can be determined by the method described above for the partial polymer of monomer component M.

[0125] Polymer B preferably contains a structural unit derived from monomer b having a double bond-containing ring. Polymer B containing a structural unit derived from monomer b can contribute to improving the refractive index of the pressure-sensitive adhesive sheet. Examples of monomer b include those mentioned above for monomer a. Monomer b may be the same as or different from monomer a.

[0126] In the monomer b, the double bond-containing ring is preferably an aromatic ring. The monomer b may contain two or more aromatic rings (preferably carbon rings) in one molecule, and preferably contains a monomer having two or more aromatic rings and at least one ethylenically unsaturated group in one molecule (aromatic ring-multiple-containing monomer). The monomer b particularly preferably contains phenoxybenzyl acrylate.

[0127] The content of the structural units derived from monomer b in polymer B is, for example, 10% by weight or more, and may be 30% by weight or more, 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more, 95% by weight or more, 97% by weight or more, 98% by weight or more, 99% by weight or more, or even 100% by weight. In some cases, the content may be 10% by weight or less, 5% by weight or less, or even 1% by weight or less. Polymer B may not contain any structural units derived from monomer b.

[0128] The polymer B may contain a structural unit derived from a monomer c other than the above-mentioned monomer b. Examples of the monomer c include those mentioned above as the monomer d in the description of the monomer component M (hydroxyl group-containing monomers, (meth)acrylic acid alkyl esters having an alkyl group of 1 to 20 carbon atoms in the side chain, aliphatic ring-containing monomers, carboxyl group-containing monomers, etc.).

[0129] The content of structural units derived from hydroxyl group-containing monomers in polymer B is, for example, 25% by weight or less, and may be 20% by weight or less, 15% by weight or less, 12% by weight or less, 10% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, or even 1% by weight or less. The lower limit of the content may be, for example, 0.01% by weight or more, 0.1% by weight or more, or even 0.5% by weight or more. Polymer B may not contain structural units derived from hydroxyl group-containing monomers.

[0130] The content of structural units derived from a (meth)acrylic acid alkyl ester in polymer B may be, for example, 50% by weight or less, 40% by weight or less, 30% by weight or less, 25% by weight or less, 20% by weight or less, 15% by weight or less, 10% by weight or less, 7% by weight or less, 5% by weight or less, or even 4% by weight or less. The lower limit of the content may be, for example, 0.01% by weight or more, 0.1% by weight or more, 0.5% by weight or more, or even 1% by weight or more. In some cases, the lower limit of the content may be 50% by weight or more. Polymer B may not contain structural units derived from a (meth)acrylic acid alkyl ester.

[0131] The content of the structural units derived from the alicyclic-containing monomer in the polymer B is, for example, 50% by weight or less, and may be 40% by weight or less, 30% by weight or less, 25% by weight or less, 20% by weight or less, 15% by weight or less, 10% by weight or less, 7% by weight or less, 5% by weight or less, 4% by weight or less, 3% by weight or less, or even 2% by weight or less. The lower limit of the content is, for example, 0.01% by weight or more, 0.1% by weight or more, 0.5% by weight or more, or even 1% by weight or more. In some cases, the lower limit of the content may be 50% by weight or more, 80% by weight or more, or even 90% by weight or more. The polymer B may not contain any structural units derived from the alicyclic-containing monomer.

[0132] The content of structural units derived from carboxyl group-containing monomers in polymer B is, for example, 10% by weight or less, and may be 7% by weight or less, 5% by weight or less, 3% by weight or less, or even 1% by weight or less. The lower limit of the content may be, for example, 0.01% by weight or more, 0.1% by weight or more, 0.5% by weight or more, or even 1% by weight or more. It is preferable that polymer B does not contain structural units derived from carboxyl group-containing monomers.

[0133] Another example of the monomer c is a nitrogen atom-containing monomer. The nitrogen atom-containing monomer refers to a monomer having at least one nitrogen atom in the molecule (per molecule).

[0134] Examples of the nitrogen atom-containing monomer include N-vinyl cyclic amide, (meth)acrylamide, etc. The nitrogen atom-containing monomer may be used alone or in combination of two or more kinds.

[0135] Examples of N-vinyl cyclic amides include N-vinyl-2-pyrrolidone (NVP), N-vinyl-2-piperidone, N-vinyl-2-caprolactam, N-vinyl-3-morpholinone, N-vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholinedione, and vinylmethyloxazolidinone. Examples of (meth)acrylamides include (meth)acrylamide, N-alkyl(meth)acrylamide, and N,N-dialkyl(meth)acrylamide. Examples of (meth)acrylamides include various N-hydroxyalkyl(meth)acrylamides and N-alkoxyalkyl(meth)acrylamides.

[0136] Examples of nitrogen atom-containing monomers other than N-vinyl cyclic amides and (meth)acrylamides include amino group-containing monomers such as aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; cyano group-containing monomers such as acrylonitrile and methacrylonitrile; (meth)acryloylmorpholine, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, N-vinylpyrazine, N-vinylmorpholine, N-vinylpyrazole, vinylpyridine, vinylpyrimidine, vinyloxazole, vinylisoxazole, vinylthiazole, vinylisothiazole, vinylpyridazine, (meth)acryloylpyrrolidone, (meth)acryloylpyrrolidine, (meth)acryloylpiperidine, N-methylvinyl heterocycle-containing monomers such as N-isopropylpyrrolidone; maleimide-based monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; itaconimide-based monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-laurylitaconimide, and N-cyclohexylitaconimide; imide group-containing monomers such as succinimide-based monomers of N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth)acryloyl-8-oxyoctamethylenesuccinimide; and isocyanate group-containing monomers such as 2-(meth)acryloyloxyethylisocyanate.

[0137] The content of the constitutional units derived from the nitrogen atom-containing monomer in polymer B is, for example, 25% by weight or less, and may be 20% by weight or less, 15% by weight or less, 12% by weight or less, 10% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, or even 1% by weight or less. The lower limit of the content may be, for example, 0.01% by weight or more, 0.1% by weight or more, or even 0.5% by weight or more. Polymer B may not contain constitutional units derived from the nitrogen atom-containing monomer.

[0138] Another example of the monomer c is an ether group-containing monomer. The ether group-containing monomer has at least one ether group and at least one ethylenically unsaturated group in one molecule. The ether group-containing monomer may be used alone or in combination of two or more kinds.

[0139] Examples of the ethylenically unsaturated group are the same as those mentioned above in the description of monomer A. The ether group-containing monomer may be a (meth)acrylic monomer.

[0140] Examples of the ether group-containing monomer are 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, and methoxydipropylene glycol (meth)acrylate. The ether group-containing monomer is preferably 2-(2-ethoxyethoxy)ethyl acrylate (CBA).

[0141] The content of the structural units derived from the ether group-containing monomer in polymer B is, for example, 40% by weight or less, and may be 30% by weight or less, 25% by weight or less, 20% by weight or less, 15% by weight or less, 12% by weight or less, 10% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, or even 1% by weight or less. The lower limit of the content is, for example, 0.01% by weight or more, 0.1% by weight or more, or even 0.5% by weight or more. Polymer B may not contain any structural units derived from the ether group-containing monomer.

[0142] Polymer B can be produced by known polymerization methods such as solution polymerization, radiation polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations such as polymerization under supercritical conditions. Radiation that can be used for radiation polymerization includes electron beams, UV rays, and microwaves. The resulting polymer B may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

[0143] The content of polymer B in pressure-sensitive adhesive composition A is, for example, 0.1 parts by weight or more, and may be 0.5 parts by weight or more, 1.0 parts by weight or more, 2.0 parts by weight or more, 3.0 parts by weight or more, 4.0 parts by weight or more, 5.0 parts by weight or more, 6.0 parts by weight or more, 7.0 parts by weight or more, 8.0 parts by weight or more, 9.0 parts by weight or more, 10.0 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, or even 40 parts by weight or more, relative to 100 parts by weight of monomer component M. The upper limit of the content is, for example, 60 parts by weight or less, 55 parts by weight or less, 50 parts by weight or less, or even 45 parts by weight or less.

[0144] When the pressure-sensitive adhesive composition A contains inorganic particles (described below), the content of the polymer B relative to 100 parts by weight of the total of the monomer component M and the inorganic particles (specifically, a mixture of the inorganic particles and the dispersant) may be 0.1 parts by weight or more, 0.5 parts by weight or more, 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, 5 parts by weight or more, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, 9 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, or even 20 parts by weight or more. The upper limit of the content may be 50 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, or even 30 parts by weight or less. The content may be 1 to 30 parts by weight, or even 2 to 30 parts by weight.

[0145] The content of acidic groups (particularly COOH groups) in polymer B is, for example, 0.1 wt % or less, 0.01 wt % or less, or even 0.001 wt % or less. Polymer B preferably contains substantially no acidic groups. The acidic group content can be measured, for example, by the following method. First, a sol component (non-crosslinked component) contained in pressure-sensitive adhesive sheet 1 is extracted using a solvent (e.g., toluene). A component (polymer B) having a weight-average molecular weight of 1,500 to 30,000 is separated using preparative GPC (gel permeation chromatography). This component is dried in an oven at 130°C for 2 hours to remove the solvent. The acidic group content can be determined by evaluating the dried component using infrared spectroscopy.

[0146] <1-2-e. Inorganic particles> The pressure-sensitive adhesive composition A may contain inorganic particles. The inorganic particles can contribute to improving the refractive index of the pressure-sensitive adhesive sheet. The inorganic particles are preferably in a dispersed state in the pressure-sensitive adhesive composition A.

[0147] The inorganic particles can be selected from, for example, metal compound particles and metal particles, one or more types depending on the desired purpose, such as improving the refractive index. The metal compound particles may be metal oxide particles. Examples of materials constituting the metal oxide particles include titanium oxide, zirconium oxide, cerium oxide, aluminum oxide, zinc oxide, tin oxide, copper oxide, barium titanate, and niobium oxide. The metal oxide particles can be used alone or in combination of two or more types. The inorganic particles preferably contain zirconium oxide, and may be zirconium oxide particles composed essentially of zirconium oxide alone. The zirconium oxide particles can contribute to increasing the refractive index of the pressure-sensitive adhesive sheet.

[0148] The material constituting the metal compound particles may be a metal hydroxide such as aluminum hydroxide, boehmite, magnesium hydroxide, calcium hydroxide, zinc hydroxide, iron hydroxide, copper hydroxide, barium hydroxide, basic magnesium carbonate, hydrotalcite, or a hydrated metal compound. Examples of the material constituting the metal particles are iron, zinc, tungsten, and platinum.

[0149] The material of the inorganic particles may be a high-entropy alloy in which multiple types of elements are mixed.

[0150] The inorganic particles may be surface-treated. One example of the surface treatment is hydrophobization. In this specification, it is preferable that the inorganic particles do not include carbon black particles.

[0151] The inorganic particles may contain a high refractive index material. The refractive index of the high refractive index material is, for example, 1.60 or more, and may be 1.70 or more, 1.80 or more, or even 2.00 or more. The upper limit of the refractive index of the high refractive index material is not particularly limited and may be, for example, 3.00 or less, 2.80 or less, 2.50 or less, or even 2.20 or less. The refractive index of the material contained in the inorganic particles can be determined as the refractive index measured for a monolayer film of the material using a commercially available spectroscopic ellipsometer at 23°C and 549 nm. The spectroscopic ellipsometer may be, for example, an "EC-400" (manufactured by J.A. Woolam) or an equivalent.

[0152] The inorganic particles may be nanoparticles having an average particle size of less than 1 μm. The average particle size of the inorganic particles may be 100 nm or less. The average particle size may be 70 nm or less, 50 nm or less, 30 nm or less, 20 nm or less, 15 nm or less, 10 nm or less, 7 nm or less, 5 nm or less, or even 4 nm or less. The lower limit of the average particle size may be, for example, 1 nm or more, 1.5 nm or more, 2 nm or more, or even 2.5 nm or more. The average particle size can be specified as the median diameter (D50) in the particle size distribution measured by dynamic light scattering.

[0153] The content of the inorganic particles relative to 100 parts by weight of the total of the monomer component M and the inorganic particles (more specifically, a mixture of the inorganic particles and the dispersant) may be, for example, 10 parts by weight or more, 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 36 parts by weight or more, 37 parts by weight or more, 38 parts by weight or more, 39 parts by weight or more, 40 parts by weight or more, 41 parts by weight or more, 42 parts by weight or more, 43 parts by weight or more, 44 parts by weight or more, 45 parts by weight or more, 46 parts by weight or more, 47 parts by weight or more, 48 parts by weight or more, 49 parts by weight or more, 50 parts by weight or more, 51 parts by weight or more, 52 parts by weight or more, 53 parts by weight or more, 54 parts by weight or more, 55 parts by weight or more, 56 parts by weight or more, 57 parts by weight or more, 58 parts by weight or more, 59 parts by weight or more, or even 60 parts by weight or more. The upper limit of the content is, for example, 90 parts by weight or less, and may be 80 parts by weight or less, 70 parts by weight or less, or even 60 parts by weight or less. The content is preferably 40 to 60 parts by weight.

[0154] <1-2-f. Dispersants> The PSA composition A may contain a dispersant for inorganic particles. The dispersant is a component for sufficiently dispersing the inorganic particles in the PSA composition A. The dispersant is preferably in contact with the surfaces of the inorganic particles, and more preferably coats the surfaces of the inorganic particles.

[0155] An example of a dispersant is a compound having a hydrophilic portion and a hydrophobic portion in one molecule. The hydrophilic portion and the hydrophobic portion of the dispersant are presumed to exhibit relatively high affinity for the inorganic particles and the monomer component M, respectively. The dispersant may or may not have a polymerizable functional group such as an ethylenically unsaturated group.

[0156] The hydrophilic portion of the dispersant preferably has a hydrophilic group, such as an ether group or an ester group.

[0157] The hydrophilic portion of the dispersant preferably has a functional group F that exhibits adsorptivity or reactivity with inorganic particles. Examples of the functional group F include at least one selected from the group consisting of alkaline groups and acidic groups. Specific examples of the functional group F include a hydroxy group, a carboxy group, a nitrogen atom-containing group, a sulfur atom-containing group, a phosphorus atom-containing group, and a silicon atom-containing group. The number of functional groups F contained in one molecule of the dispersant may be 1, or 2 or more (for example, about 2 to 5). The types of the two or more functional groups F present in one molecule may be the same or different from each other.

[0158] The hydrophilic portion of the dispersant may have a chain structure, or may have a composite structure of a chain structure and a cyclic structure. The dispersant may have, for example, a structure in which a functional group F and a hydrophobic portion are linked via a chain structure; a structure in which a functional group F is attached to a side chain of a chain structure whose one end is linked to the hydrophobic portion; or a structure in which a chain structure whose other end is linked to the hydrophobic portion does not have a functional group F (for example, the other end of the chain structure is open). The dispersant may have two or more of the above structures.

[0159] The dispersant may be an aliphatic compound, for example, represented by the following formula (2): [ka]

[0160] In formula (2), R is an alkyl group, preferably an alkyl group having 1 to 3 carbon atoms, and more preferably an ethyl group. m is 1 to 10, preferably 2 to 8, and more preferably 3 to 7. n is 5 to 20, and preferably 8 to 12.

[0161] The dispersant may be an aromatic compound having an aromatic ring. Examples of the aromatic ring are the same as those mentioned above in the description of the monomers a and b.

[0162] The dispersant may be selected from known surfactants. Examples of surfactants include anionic surfactants (carboxylic acid type, phosphate ester type, sulfate ester type, sulfonic acid type, etc.), nonionic surfactants, cationic surfactants, and amphoteric surfactants. The surfactant that can be used as the dispersant is preferably an anionic surfactant.

[0163] The content of the dispersant relative to 100 parts by weight of the inorganic particles is, for example, 0.1 parts by weight or more, or may be 0.5 parts by weight or more, or even 1.0 part by weight or more. The upper limit of the content is, for example, 30 parts by weight or less, or may be 20 parts by weight or less.

[0164] <1-2-g. Crosslinking agent> The pressure-sensitive adhesive composition A may contain a crosslinking agent. An example of the crosslinking agent is a polyfunctional monomer having two or more polymerizable functional groups in one molecule. The polyfunctional monomer may be a (meth)acrylic monomer. Examples of the polyfunctional monomer are a monomer having two or more C=C bonds in one molecule, and a monomer having one or more C=C bonds and one or more polymerizable functional groups such as epoxy groups, aziridine groups, oxazoline groups, hydrazine groups, methylol groups, etc. in one molecule. The polyfunctional monomer is preferably a monomer having two or more C=C bonds in one molecule.

[0165] Examples of polyfunctional monomers include (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol diacrylate (N Polyfunctional acrylates (such as ester compounds of polyhydric alcohols and (meth)acrylic acid) such as dimethyl acrylate (DDA), 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate; allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di(meth)acrylate, and hexyl di(meth)acrylate. The polyfunctional monomer is preferably a polyfunctional acrylate, more preferably trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, or dipentaerythritol hexa(meth)acrylate.

[0166] The content of the crosslinking agent in the pressure-sensitive adhesive composition A is, for example, 5 parts by weight or less, and may be 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, or even 0.5 parts by weight or less, per 100 parts by weight of the monomer component M. The lower limit of the content may be, for example, 0.01 part by weight or more, or even 0.05 part by weight or more.

[0167] When the pressure-sensitive adhesive composition A contains inorganic particles, the content of the crosslinking agent relative to 100 parts by weight of the total of the monomer component M and the inorganic particles (specifically, a mixture of the inorganic particles and the dispersant) may be, for example, 5 parts by weight or less, 3 parts by weight or less, 2 parts by weight or less, 1 part by weight or less, or even 0.5 parts by weight or less. The lower limit of the content may be, for example, 0.01 parts by weight or more, 0.03 parts by weight or more, or even 0.05 parts by weight or more.

[0168] <1-2-h. Silane coupling agents> The pressure-sensitive adhesive composition A may contain a silane coupling agent. Specific examples of the silane coupling agent include epoxy group-containing silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino group-containing silane coupling agents such as 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl-γ-aminopropyltrimethoxysilane; (meth)acrylic group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane.

[0169] The content of the silane coupling agent in the pressure-sensitive adhesive composition A is, for example, 3 parts by weight or less, and may be 2 parts by weight or less, 1 part by weight or less, or even 0.5 parts by weight or less, per 100 parts by weight of the monomer component M. The lower limit of the content may be, for example, 0.1 parts by weight or more, or even 0.2 parts by weight or more. The pressure-sensitive adhesive composition A may not contain a silane coupling agent.

[0170] When the pressure-sensitive adhesive composition A contains inorganic particles, the content of the silane coupling agent relative to 100 parts by weight of the total of the monomer component M and the inorganic particles (specifically, a mixture of the inorganic particles and the dispersant) is, for example, 5 parts by weight or less, and may be 3 parts by weight or less, 1 part by weight or less, 0.8 parts by weight or less, 0.5 parts by weight or less, 0.4 parts by weight or less, 0.3 parts by weight or less, 0.2 parts by weight or less, or even 0.1 parts by weight or less. The lower limit of the content is, for example, 0.01 parts by weight or more, and may also be 0.05 parts by weight or more.

[0171] <1-2-i. Antioxidants> The PSA composition A may contain an antioxidant. Examples of the antioxidant include phenol-based antioxidants, hindered phenol-based antioxidants, amine-based antioxidants, and phosphite-based antioxidants.

[0172] Examples of the phenolic antioxidant include monophenolic antioxidants, bisphenolic antioxidants, and polymeric phenolic antioxidants. Examples of the monophenolic antioxidant include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, and stearin-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate. Examples of the bisphenol antioxidant are 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), and 3,9-bis[1,1-dimethyl-2-[β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane. Examples of polymeric phenolic antioxidants include 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid]glycol ester, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-S-triazine-2,4,6-(1H,3H,5H)trione, and tocopherol.

[0173] The hindered phenol-based antioxidant may have a structure in which a tertiary butyl group is bonded to at least one carbon atom adjacent to a carbon atom on an aromatic ring to which a phenolic OH group is bonded. Examples of hindered phenolic antioxidants include dibutylhydroxytoluene (BHT); and Irganox1010, Irganox1010FF, Irganox1035, Irganox1035FF, Irganox1076, Irganox1076FD, Irganox1076DWJ, Irganox1098, Irganox1135, Irganox1330, Irganox1726, Irganox1425WL, Irganox1520L, Irganox245, Irganox245FF, Irganox259, Irganox3114, Irganox565, and Irganox295 (all of which are trade names manufactured by BASF).

[0174] The amine antioxidant is preferably a hindered amine antioxidant. The hindered amine antioxidant may have at least one hindered piperazine group in one molecule. Examples of the hindered amine antioxidant include ADK STAB LA-63, ADK STAB LA-63P, ADK STAB LA-52, and ADK STAB LA-57 (all of which are trade names, manufactured by ADEKA Corporation).

[0175] Examples of the phosphite antioxidants are triphenyl phosphite, diphenyl isodecyl phosphite, and phenyl diisodecyl phosphite; and Adeka STAB 2112, Adeka STAB 2112RG, Adeka STAB 1178, and Adeka STAB 3010 (all of which are trade names, manufactured by ADEKA Corporation).

[0176] The content of the antioxidant in the pressure-sensitive adhesive composition A is, for example, 5 parts by weight or less, and may be 3 parts by weight or less, 1 part by weight or less, 0.8 parts by weight or less, or even 0.5 parts by weight or less, per 100 parts by weight of the monomer component M. The lower limit of the content may be, for example, 0.01 parts by weight or more, or even 0.05 parts by weight or more. The pressure-sensitive adhesive composition A may not contain an antioxidant.

[0177] When the pressure-sensitive adhesive composition A contains inorganic particles, the content of the antioxidant relative to 100 parts by weight of the total of the monomer component M and the inorganic particles (specifically, a mixture of the inorganic particles and the dispersant) is, for example, 5 parts by weight or less, or may be 3 parts by weight or less, 1 part by weight or less, 0.8 parts by weight or less, or even 0.5 parts by weight or less. The lower limit of the content is, for example, 0.01 parts by weight or more, or may be 0.05 parts by weight or more.

[0178] <1-2-j. UV absorbers> The pressure-sensitive adhesive composition A may contain an ultraviolet absorber (UVA). Examples of UVA include triazine-based UVA, benzotriazole-based UVA, benzophenone-based UVA, oxybenzophenone-based UVA, salicylic acid ester-based UVA, and cyanoacrylate-based UVA. Each UVA is a compound having a triazine skeleton, a benzotriazole skeleton, a benzophenone skeleton, an oxybenzophenone skeleton, a salicylic acid ester structure, and a cyanoacrylate structure, respectively. The UVA is preferably a triazine-based or benzotriazole-based UVA, and more preferably a benzotriazole-based UVA.

[0179] Examples of triazine-based UVAs include 2,4-bis-[{4-(4-ethylhexyloxy)-4-hydroxy}-phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine (Tinosorb S, manufactured by BASF), 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triazine (TINUVIN460, manufactured by BASF), reaction product of 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hydroxyphenyl with [(C10-C16 (mainly C12-C13) alkyloxy)methyl]oxirane (TINUVIN400, manufactured by BASF), and 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-[3-(dodecyloxy)methyl]oxirane. )-2-hydroxypropoxy]phenol), reaction products of 2-(2,4-dihydroxyphenyl)-4,6-bis-(2,4-dimethylphenyl)-1,3,5-triazine with (2-ethylhexyl)-glycidic acid ester (TINUVIN 405, BASF), 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol (TINUVIN 1577, BASF), 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[2-(2-ethylhexanoyloxy)ethoxy]-phenol (ADK STAB LA46 (manufactured by ADEKA), and 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (TINUVIN479 (manufactured by BASF)).

[0180] Examples of benzotriazole-based UVAs include 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN 928, manufactured by BASF), 2-(2H-1,2,3-benzotriazol-2-yl)-6-dodecyl-4-methylphenol (TINUVIN 571, manufactured by BASF), 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole (TINUVIN PS, manufactured by BASF), ester compound of benzenepropanoic acid and 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy(C7-9 branched and linear alkyl) (TINUVIN 384-2, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN 900, manufactured by BASF), reaction product of methyl-3-(3-(2H-benzotriazol-2-yl)-5-t-butyl-4-hydroxyphenyl)propionate / polyethylene glycol 300 (TINUVIN 1130, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-p-cresol (TINUVIN P, manufactured by BASF), 2(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN234, manufactured by BASF), 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol (TINUVIN326, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (TINUVIN328, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN234, manufactured by BASF), 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol (TINUVIN326, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (TINUVIN328, manufactured by BASF), -yl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN329, manufactured by BASF), reaction products of methyl 3-(3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionate with polyethylene glycol 300 (TINUVIN213, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol (TINUVIN571, manufactured by BASF), 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimido-methyl)-5-methylphenyl]benzotriazole (Sumisorb 250, manufactured by Sumitomo Chemical Co., Ltd.).

[0181] The content of UVA in the pressure-sensitive adhesive composition A is, for example, 10 parts by weight or less, and may be 5 parts by weight or less, 3 parts by weight or less, or even 2 parts by weight or less, relative to 100 parts by weight of the monomer component M. The lower limit of the content may be, for example, 0.1 parts by weight or more, 0.5 parts by weight or more, or even 1 part by weight or more. The pressure-sensitive adhesive composition A may not contain UVA.

[0182] When the PSA composition A contains inorganic particles, the content of UVA relative to 100 parts by weight of the total of the monomer component M and the inorganic particles (specifically, a mixture of the inorganic particles and the dispersant) is, for example, 10 parts by weight or less, or may be 5 parts by weight or less, 3 parts by weight or less, or even 2 parts by weight or less. The lower limit of the content is, for example, 0.1 parts by weight or more, or may be 0.5 parts by weight or more, or even 1 part by weight or more.

[0183] <1-2-k. Solvent> The content of the solvent in the PSA composition A is, for example, 5 wt % or less, and may be 4 wt % or less, 3 wt % or less, 2 wt % or less, 1 wt % or less, or even 0.5 wt % or less. The PSA composition A may be substantially free of solvent. "Substantially free of solvent" means that solvents derived from additives and the like are allowed at a content of, for example, 0.1 wt % or less, preferably 0.05 wt % or less, and more preferably 0.01 wt % or less.

[0184] <1-2-1. Additives> The PSA composition A may contain additives other than those described above. Examples of the additives include a chain transfer agent, a viscosity modifier, a tackifier, a plasticizer, a softener, an antioxidant, a filler, a colorant, a surfactant, and an antistatic agent.

[0185] <1-2-m.Physical properties> The viscosity of the pressure-sensitive adhesive composition A is preferably 5 to 150 poise at 25° C. The pressure-sensitive adhesive composition A having a viscosity in the above range is particularly suitable for forming a coating layer, which will be described later.

[0186] <1-2-n. Manufacturing method> The pressure-sensitive adhesive composition A can be prepared by mixing the various components. The pressure-sensitive adhesive composition A containing inorganic particles may be prepared by the following method. First, a dispersion in which inorganic particles are dispersed in a solvent is prepared. This dispersion is mixed with a dispersant and at least some of the monomers contained in the monomer component M. The solvent is removed from the resulting mixture to prepare a dispersion containing inorganic particles, a dispersant, and a monomer. The method for removing the solvent from the mixture is not particularly limited, and methods such as removal under reduced pressure can be used. Next, the remaining monomers, polymer B, a photopolymerization initiator, etc. are added to the dispersion and mixed. In this way, the pressure-sensitive adhesive composition A containing inorganic particles can be prepared.

[0187] 2. Manufacturing method of optical film with adhesive sheet An example of a method for producing an optical film with a pressure-sensitive adhesive sheet according to an embodiment of the present invention is shown in Figure 2. In the example of Figure 2, release liner 13 is peeled off from second laminate 17 formed by the method described above, and optical film 2 is placed on exposed surface 18 of pressure-sensitive adhesive sheet 1 formed by the peeling, to form optical film 21 with a pressure-sensitive adhesive sheet.

[0188] The pressure-sensitive adhesive sheet-attached optical film 21 includes a base sheet 11, a pressure-sensitive adhesive sheet 1, and an optical film 2, in this order. The pressure-sensitive adhesive sheet-attached optical film 21 can be used in an image display device or the like as an optical laminate including the pressure-sensitive adhesive sheet 1 and the optical film 2, either as is or after the base sheet 11 has been peeled off. The optical laminate may be attached to an object (e.g., an image-forming panel) via the pressure-sensitive adhesive sheet 1. However, the uses of the pressure-sensitive adhesive sheet-attached optical film 21 are not limited to the above examples. An additional member such as an optical film may be disposed on the exposed surface 18 formed by peeling off the base sheet 11 from the pressure-sensitive adhesive sheet-attached optical film 21. As an example, a pressure-sensitive adhesive sheet-attached optical film 22 can be formed, including an optical film 2A, a pressure-sensitive adhesive sheet 1, and an optical film 2B, in this order (see FIG. 3). The optical films 2A and 2B may be the same or different from each other.

[0189] The optical film 2 may be disposed directly or indirectly on the exposed surface 18. In other words, the optical film 2 may be disposed so as to be in contact with the exposed surface 18, or may be disposed with another layer sandwiched between the optical film 2 and the exposed surface 18.

[0190] The optical film 2 is, for example, a film including at least one selected from the group consisting of a polarizing film and a retardation film. The optical film 2 may be a laminated film including a polarizing film and / or a retardation film. The optical film 2 may include a glass film. However, the optical film 2 is not limited to the above examples.

[0191] The optical film 2 may be a polarizing film, and the pressure-sensitive adhesive sheet 1 may be in contact with the optical film 2 .

[0192] The polarizing film includes a polarizer. The polarizing film typically includes a polarizer and a protective film (transparent protective film). The protective film is disposed, for example, in contact with the main surface (the surface having the largest area) of the polarizer. The polarizer may be disposed between two protective films. The protective film may be disposed on at least one surface of the polarizer.

[0193] The polarizer is not particularly limited, and examples include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and partially saponified ethylene-vinyl acetate copolymer films, which are uniaxially stretched after adsorbing a dichroic substance such as iodine or a dichroic dye; and oriented polyene films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride. Polarizers typically consist of a polyvinyl alcohol film (including partially saponified ethylene-vinyl acetate copolymer films) and a dichroic substance such as iodine.

[0194] The thickness of the polarizer is not particularly limited and may be, for example, 80 μm or less, 50 μm or less, 30 μm or less, 25 μm or less, or even 20 μm or less. The lower limit of the polarizer thickness is not particularly limited and may be, for example, 1 μm or more, 5 μm or more, 10 μm or more, or even 15 μm or more. A thin polarizer (for example, a thickness of 20 μm or less) is suppressed in dimensional change and can contribute to improving the durability of the optical laminate, particularly durability at high temperatures.

[0195] The material for the protective film may be, for example, a thermoplastic resin that is excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene-based resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The material for the protective film may be a thermosetting resin or an ultraviolet-curable resin such as a (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone-based resin. When the polarizing film has two protective films, the materials of the two protective films may be the same or different. For example, a protective film made of a thermoplastic resin may be bonded to one main surface of a polarizer via an adhesive, and a protective film made of a thermosetting resin or an ultraviolet-curable resin may be bonded to the other main surface of the polarizer. The protective film may contain one or more optional additives, such as ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, color inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.

[0196] The thickness of the protective film can be determined as appropriate, but is generally about 10 to 200 μm in terms of strength, workability such as handling, thinness, and the like.

[0197] The polarizer and the protective film are usually adhered to each other via an aqueous adhesive or the like. Examples of aqueous adhesives include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl latex, aqueous polyurethane, and aqueous polyester. Examples of adhesives other than the above-mentioned adhesives include ultraviolet-curable adhesives and electron beam-curable adhesives. Electron beam-curable polarizing film adhesives exhibit suitable adhesiveness to various protective films. The adhesive may contain a metal compound filler.

[0198] In the polarizing film, a retardation film or the like can be formed on the polarizer instead of the protective film. Another protective film or a retardation film or the like can be further provided on the protective film.

[0199] In the polarizing film, a retardation film or the like can be formed on the polarizer instead of the protective film. Another protective film or a retardation film or the like can be further provided on the protective film.

[0200] The protective film may have a hard coat layer on the surface opposite to the surface bonded to the polarizer, and may also be subjected to treatments for purposes such as anti-reflection, anti-sticking, diffusion, and anti-glare.

[0201] The polarizing film may be a circular polarizing film.

[0202] The thickness of the polarizing film is, for example, 500 μm or less, and may be 300 μm or less, 200 μm or less, 100 μm or less, or even 60 μm or less. The lower limit of the thickness may be, for example, 10 μm or more, 25 μm or more, or even 40 μm or more.

[0203] A retardation film is a film having birefringence in the in-plane direction and / or the thickness direction, and is, for example, a stretched resin film or a film in which a liquid crystal material is oriented and fixed.

[0204] The retardation film may be a λ / 4 plate, a λ / 2 plate, an anti-reflection retardation film (see, for example, paragraphs 0221, 0222, and 0228 of JP 2012-133303 A), a viewing angle compensation retardation film (see, for example, paragraphs 0225 and 0226 of JP 2012-133303 A), or an obliquely oriented viewing angle compensation retardation film (see, for example, paragraph 0227 of JP 2012-133303 A). The retardation film is not limited to the above examples, as long as it has birefringence in the in-plane direction and / or the thickness direction. The retardation value, arrangement angle, three-dimensional birefringence, whether the retardation film is single-layer or multi-layer, and the like are also not limited. Known films can be used as the retardation film.

[0205] The optical film 2 has a thickness of, for example, 1 to 200 μm.

[0206] The optical film 2 may be a single layer or a laminated film composed of two or more layers. When the optical film 2 is a laminated film, the pressure-sensitive adhesive sheet 1 may be used to bond the layers together.

[0207] The formed optical film with a pressure-sensitive adhesive sheet can be distributed and stored, for example, as a rolled body obtained by rolling up a strip, or as a sheet of optical film with a pressure-sensitive adhesive sheet.

[0208] The formed optical film with a pressure-sensitive adhesive sheet is typically used in image display devices, such as liquid crystal displays, organic EL displays, and inorganic EL displays.

[0209] 3. Method for manufacturing image display device An image display device may be formed using the optical film with a pressure-sensitive adhesive sheet formed by the above-mentioned method. The image display device can be formed, for example, by bonding the optical film with a pressure-sensitive adhesive sheet 21, 22 to an image display panel. The bonding may be performed using a pressure-sensitive adhesive sheet 1. The image display device may be an organic EL display or a liquid crystal display. However, the image display device is not limited to the above examples. The image display device may be an electroluminescence (EL) display, a plasma display (PD), a field emission display (FED), etc. The image display device can be used for home appliances, in-vehicle applications, public information displays (PID), etc. [Example]

[0210] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples in any way.

[0211] <Synthesis of Polymer B> [Synthesis of Polymer B1] A four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser was charged with 99 parts by weight of POB-A, 1 part by weight of 4-hydroxybutyl acrylate (4HBA), 0.30 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator, 3 parts by weight of 1-thioglycerol as a chain transfer agent, and 300 parts by weight of ethyl acetate. The mixture was maintained at 70°C and stirred gently while introducing nitrogen gas. After sufficient nitrogen substitution for at least 1 hour, the temperature in the flask was maintained at 72-74°C and the polymerization reaction was carried out for 6 hours to prepare a solution of polymer B1. The solution was then heated at 90°C for 12 hours, followed by 3 hours of reduced pressure treatment at 120°C to remove the ethyl acetate. This yielded polymer B1, in which the amount of ethyl acetate detected by gas chromatography was less than 0.1 parts by weight.

[0212] [Synthesis of Polymer B2] Polymer B2 was synthesized in the same manner as polymer B1, except that the types and contents of the monomer, polymerization initiator, and chain transfer agent were changed as shown in Table 1.

[0213] [Mw of polymer B] The Mw of the obtained polymer B was measured by GPC (gel permeation chromatography) using the following measuring device and conditions: Analytical equipment: Waters, Alliance Column: Tosoh TSKgel SuperHZM-H x 2 Column temperature: 40℃ ·Eluent:THF ·Flow rate: 0.2mL / min ·Injection volume: 30μL Detector: Refractive index (RI) Standard sample: Agilent, polystyrene (PS)

[0214] [Table 1]

[0215] The abbreviations in Table 1 are as follows: POB-A: Phenoxybenzyl acrylate (manufactured by Kyoeisha Chemical, product name "Light Acrylate POB-A") 4HBA: 4-hydroxybutyl acrylate

[0216] <Preparation of Dispersion D1> [Synthesis of dispersant d1] To 1.0 mol of propionic acid, 8.0 mol of ε-caprolactone, 0.2 mol of p-toluenesulfonic acid monohydrate, and 2.2 mol of pure water were added, and the mixture was stirred at 80°C for 8 hours. Next, stirring was continued for another 2 hours while dehydrating under reduced pressure (30 kPa). Next, the propionic acid remaining in the reaction system was distilled off, and the mixture was subjected to a purification step (washed with water three times) and a drying step to obtain dispersant d1 (a compound represented by the above formula (2) in which R is an ethyl group, m is 5, and n is 10).

[0217] [Preparation of Dispersion D1] 5 parts by weight of the above-mentioned dispersant d1 and 45 parts by weight of phenoxybenzyl acrylate (manufactured by Kyoeisha Chemical Industry Co., Ltd., trade name "Light Acrylate POB-A"; hereinafter referred to as "POB-A") were added to and mixed with 167 parts by weight of a methanol dispersion of zirconium oxide particles (manufactured by Sakai Chemical Industry Co., Ltd., grade name "SZR-GM," average particle diameter (D50) based on dynamic light scattering: approximately 10 nm, zirconium oxide particle concentration: 30% by weight). Next, the solvent was removed under reduced pressure using a rotary evaporator to obtain Dispersion D1, a dispersion of zirconium oxide particles. Dispersion D1 contained zirconium oxide particles / Dispersant d1 / POB-A in a weight ratio of 50 / 5 / 45.

[0218] <Preparation of Dispersion D2> [Synthesis of dispersant d2] 415 g (1 mol) of tristyrenated phenol and 1 g (0.018 mol) of potassium hydroxide were charged into an autoclave and mixed uniformly. The resulting reaction system was heated to 130°C, and 352 g (8 mol) of ethylene oxide (EO) was added dropwise. After the dropwise addition was completed, the temperature was maintained at 130°C and the pressure was maintained at 0.1 MPa, and the mixture was aged for 1 hour to obtain an EO 8 mol adduct of tristyrenated phenol. Next, 767 g (1 mol) of the resulting EO 8 mol adduct of tristyrenated phenol and 152 g (1.3 mol) of sodium monochloroacetate were added to the reactor and stirred until uniform. Next, the reaction system was heated to 60°C and 52 g of sodium hydroxide was added, followed by heating to 80°C and aging for 3 hours. After aging, the mixture was cooled to 50°C, and 117 g (1.2 mol) of 98 wt% sulfuric acid was added dropwise at the same temperature to obtain a white suspension. The resulting suspension was washed with distilled water, and the solvent was removed by distillation under reduced pressure to obtain dispersant d2.

[0219] To 100 parts by weight of a methanol dispersion of zirconium oxide particles (manufactured by Sakai Chemical Industry Co., Ltd., grade name "SZR-M", average particle size (D50) based on dynamic light scattering: 3 nm, zirconium oxide particle concentration: 30 wt %), 1.5 parts by weight of the above-mentioned dispersant d2 and 28.5 parts by weight of POB-A were added and mixed. Next, the solvent was removed under reduced pressure using a rotary evaporator to obtain Dispersion D2, a dispersion of zirconium oxide particles. Dispersion D2 contained zirconium oxide particles / Dispersant d2 / POB-A in a weight ratio of 50 / 2.5 / 47.5.

[0220] <Preparation of Pressure-Sensitive Adhesive Composition A> [Preparation of Pressure-Sensitive Adhesive Composition A1] Phenoxybenzyl acrylate (POB-A) and 4-hydroxybutyl acrylate (4HBA) were mixed with Dispersion D1 to obtain a mixture containing zirconium oxide particles, Dispersant d1, POB-A, and 4HBA in the amounts shown in Table 2. 0.4 parts by weight of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by IGM Resins, trade name "Omnirad 819") as a photopolymerization initiator, 1.46 parts by weight of TINUVIN 571 (manufactured by BASF) as a UVA, 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, 0.5 parts by weight of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicones, trade name "KBM-403") as a silane coupling agent, and 0.03 parts by weight of 1,9-nonanediol diacrylate (NDDA) as a crosslinker were mixed with 100 parts by weight of this mixture to obtain Pressure-Sensitive Adhesive Composition A1.

[0221] [Adhesive compositions A2 to A10] Except for changing the composition of the mixture, the type of additive, and the content of the additive as shown in Table 2, PSA compositions A2 to A10 were obtained in the same manner as for PSA composition A1.

[0222] [Table 2]

[0223] The abbreviations in Table 2 are as follows: POB-A: Phenoxybenzyl acrylate (manufactured by Kyoeisha Chemical, product name "Light Acrylate POB-A") 4HBA: 4-hydroxybutyl acrylate ACMO: acryloylmorpholine Omni.819: bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by IGM Resins, trade name "Omnirad 819") NDDA: 1,9-nonanediol diacrylate Tinuvin 571: Benzotriazole-based UVA (manufactured by BASF, trade name "Tinuvin 571") Tinuvin 384-2: Benzotriazole-based UVA (manufactured by BASF, trade name "Tinuvin 384-2") KBM403: 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicones Co., Ltd., product name "KBM-403") Irganox 1010: Hindered phenolic antioxidant (manufactured by BASF, product name "Irganox 1010")

[0224] Example 1 Using the pressure-sensitive adhesive composition A1 prepared above, a pressure-sensitive adhesive sheet was prepared by the following method.

[0225] [Preparation of release liner] A silicone-based release agent composition was prepared by mixing 30 parts by weight of an addition reaction curable silicone (LTC761 containing a hexenyl group-containing polyorganosiloxane, a 30 wt% toluene solution, manufactured by Dow Corning Toray Co., Ltd.), 0.9 parts by weight of a release control agent (BY24-850 containing an unreactive silicone resin, manufactured by Dow Corning Toray Co., Ltd.), 2 parts by weight of a curing catalyst (SRX212 containing a platinum catalyst, manufactured by Dow Corning Toray Co., Ltd.), and a toluene / hexane mixed solvent (volume ratio 1:1) as a diluent. The silicone solids concentration in the release agent composition was 1.0 wt%. Next, the release agent composition was applied to one side of a liner substrate (Lumirror XD500P polyester film, 75 μm thick) using a wire bar and heated at 130°C for 1 minute to prepare a release liner with a release layer (60 nm thick) on one side.

[0226] [Preparation of adhesive sheet] The adhesive composition was applied to one side of a substrate sheet (PET separator, Mitsubishi Plastics, MRF38) using an applicator to form a coating layer. Next, the release liner described above was placed on top of the formed coating layer to obtain a first laminate. The release liner was placed so that the release layer was in contact with the coating layer.

[0227] Next, an illuminance of 9 mW / cm was applied from the side of the base sheet of the first laminate. 2 At the same time, ultraviolet light from a black light source was irradiated from the release liner side of the first laminate under the conditions of 2 The total cumulative light intensity of both light irradiations was 6600 mJ / cm. 2 After the first irradiation was completed, the first laminate was continuously irradiated with a light having an illuminance of 18 mW / cm from the side of the base sheet. 2 and cumulative light intensity of 2000mJ / cm 2The adhesive sheet was then irradiated with ultraviolet light for 10 seconds (second irradiation). A metal halide lamp was used as the light source. This photocured the coating layer, yielding the PSA sheet of Example 1 (50 μm thick) sandwiched between the base sheet and release liner. The illuminance of the ultraviolet light from the black light source and metal halide lamp was measured using an illuminance meter (U0-T36T2, manufactured by Topcon Technohouse) near the surface of the base sheet where the ultraviolet light was incident. The illuminance of the light from the LED was measured using an illuminance meter (UD-T3040T2, manufactured by Topcon Technohouse) near the surface of the release liner where the ultraviolet light was incident.

[0228] <Examples 2 to 16, Comparative Examples 1 and 2> Pressure-sensitive adhesive sheets (all 50 μm thick) of Examples 2 to 16 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1, except that the type of pressure-sensitive adhesive composition and the conditions for the first and second irradiation were changed as shown in Table 3 below. Note that for the first irradiation, the illuminance of the ultraviolet light from the black light source and the illuminance of the light from the LED were set to be the same as in Example 1. The integrated light amount of the first irradiation is the sum of the integrated light amount of the ultraviolet light from the black light source and the integrated light amount of the light from the LED.

[0229] <Evaluation> [Refractive Index] For each of the pressure-sensitive adhesive sheets produced, the release liner was peeled off to expose the surface, and the refractive index was measured in critical angle mode using a prism coupler (manufactured by Metricon, model "2010M") at a measurement temperature of 25°C and a measurement wavelength of 594 nm.

[0230] [Hayes] For each pressure-sensitive adhesive sheet produced, the base sheet and release liner were peeled off, and an alkali-free glass plate (0.7 to 0.8 mm thick, total light transmittance 92%, haze 0.06%) was attached to each exposed surface to obtain a test specimen in which the pressure-sensitive adhesive sheet was sandwiched between two alkali-free glass plates. This test specimen was then left in an environment of 23°C and 50% RH for 30 minutes, after which it was placed in a pressure-degassing apparatus (autoclave) and autoclaved for 30 minutes at a temperature of 50°C and a pressure of 0.5 MPa. It was then left in an atmosphere of 23°C and 50% RH for 24 hours. The haze of the test specimen was then measured using a spectroscopic haze meter (HSP-150vis, manufactured by Murakami Color Research Laboratory) at 23°C.

[0231] [chromaticity b * Absolute value of For each pressure-sensitive adhesive sheet produced, the base sheet and release liner were peeled off to expose each surface, and a non-alkali glass plate (thickness 0.7 to 0.8 mm, total light transmittance 92%, chromaticity b * 0.20) was bonded together to obtain a test piece in which the adhesive sheet was sandwiched between two alkali-free glass plates. This test piece was left in an environment of 23°C and 50% RH for 30 minutes, then placed in a pressure degassing apparatus (autoclave) and autoclaved for 30 minutes at a temperature of 50°C and a pressure of 0.5 MPa. Next, it was left in an atmosphere of 23°C and 50% RH for 24 hours. Next, in a measurement environment of 23°C, the transmittance of the above test piece for light with wavelengths from 300 nm to 800 nm was measured using a UV-Visible-Near-Infrared Spectrophotometer (Hitachi High-Tech, UH4150). Chromaticity b was calculated from the obtained spectral data using a color calculation program (Hitachi High-Tech, UV Solutions). * The absolute value of the chromaticity b * The values ​​were based on reference data (blank data) measured without placing a sample in the measurement chamber of the ultraviolet-visible-near-infrared spectrophotometer.

[0232] [Residual monomer amount] The amount of residual monomer in each of the produced pressure-sensitive adhesive sheets was evaluated by high performance liquid chromatography (HPLC) as follows. Sample preparation: Approximately 0.05 g was collected from the adhesive sheet, 2 mL of chloroform was added, and the mixture was shaken overnight. 8 mL of methanol was added to the resulting extract to reprecipitate the polymer component, and the supernatant was filtered through a membrane filter with a pore size of 0.45 μm to obtain a solution for evaluation. The resulting solution was subjected to HPLC measurement under the following conditions. Device: Agilent Technologies 1290 Infinity II Analysis conditions: Column: Waters Acquity UPLC CSH C18 (2.1 mm diameter x 150 mm, 1.7 μm) Eluent composition: Gradient conditions of ultrapure water / acetonitrile / tetrahydrofuran (THF) Column temperature = 40℃ Column flow rate = 0.5 mL / min ·Injection volume=2μL Detector = PDA Measurement wavelength: 190-400nm ·Extraction wavelength = 272nm (POB-A), 210nm (4HBA), 210nm (ACMO)

[0233] The evaluation results are shown in Table 3.

[0234] [Table 3]

[0235] As shown in Table 3, the cumulative light intensity was 7000 mJ / cm 2 The first irradiation was performed with an integrated light dose of 1600 mJ / cm 2 In the adhesive sheets of the examples formed by two or more irradiations, including the second irradiation described above, the amount of residual monomer was reduced compared to the adhesive sheets of the comparative examples, making it possible to efficiently manufacture adhesive sheets. [Industrial Applicability]

[0236] According to the manufacturing method of the present invention, for example, an optical pressure-sensitive adhesive sheet can be manufactured. [Explanation of symbols]

[0237] 1 adhesive sheet 2 Optical Film 10 (first) laminate 11 Base sheet 12 (Adhesive composition) coating layer 13 Release liner 18 (Adhesive sheet 1) exposed surface 21,22 Optical film with adhesive sheet 35, 35A, 35B Active energy rays

Claims

1. A method for producing a pressure-sensitive adhesive sheet, comprising irradiating a coating layer containing a photocurable pressure-sensitive adhesive composition with active energy rays to form a pressure-sensitive adhesive sheet from the coating layer, the irradiation of the coating layer with the active energy rays is carried out by two or more irradiations including a first irradiation and a second irradiation subsequent to the first irradiation, The cumulative amount of the active energy rays irradiated onto the coating layer in the first irradiation is 7000 mJ / cm 2 is as follows: The cumulative amount of the active energy rays irradiated onto the coating layer in the second irradiation is 1600 mJ / cm 2 That's all. A method for manufacturing an adhesive sheet.

2. The cumulative amount of the active energy rays irradiated onto the coating layer in the first irradiation is 4400 mJ / cm 2 The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the method is as follows:

3. The cumulative amount of the active energy rays irradiated onto the coating layer in the second irradiation is 3800 mJ / cm 2 The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the method is as described above.

4. The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the first irradiation and the second irradiation are carried out by irradiating a laminate including a base sheet, the coating layer, and a release liner in this order with the active energy rays.

5. a light source of the active energy rays in the first irradiation includes a black light, The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein a light source of the active energy rays in the second irradiation includes a metal halide lamp.

6. The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the method does not substantially include a step of heating the coating layer.

7. The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the pressure-sensitive adhesive sheet has a residual monomer amount of 4000 wtppm or less.

8. The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the pressure-sensitive adhesive sheet has a refractive index of 1.55 or more.

9. The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the monomer component M contained in the pressure-sensitive adhesive composition includes a (meth)acrylic monomer.

10. The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the monomer component M contained in the pressure-sensitive adhesive composition includes a monomer a having a double bond-containing ring.

11. The method for producing a pressure-sensitive adhesive sheet according to claim 10 , wherein the double bond-containing ring is an aromatic ring.

12. The method for producing a pressure-sensitive adhesive sheet according to claim 10 , wherein the content of the monomer a in the monomer component M is 50 parts by weight or more.

13. The method for producing a pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive composition comprises a polymer B having a weight-average molecular weight of 1,500 to 30,000.

14. The method for producing a pressure-sensitive adhesive sheet according to claim 13 , wherein the content of the polymer B in the pressure-sensitive adhesive composition is 55 parts by weight or less relative to 100 parts by weight of the monomer component M contained in the pressure-sensitive adhesive composition.

15. The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the pressure-sensitive adhesive composition contains inorganic particles.

16. The method for producing a pressure-sensitive adhesive sheet according to claim 15 , wherein the inorganic particles contain zirconium oxide.

17. The method for producing a pressure-sensitive adhesive sheet according to claim 15 , wherein the content of the inorganic particles is 40 parts by weight or more relative to 100 parts by weight of the total of the monomer component M and the inorganic particles contained in the pressure-sensitive adhesive composition.

18. The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the pressure-sensitive adhesive composition contains an ultraviolet absorber.

19. The method for producing a pressure-sensitive adhesive sheet according to claim 1 , wherein the pressure-sensitive adhesive composition contains a solvent in an amount of 5% by weight or less.

20. A method for producing an optical film with a pressure-sensitive adhesive sheet, comprising: placing an optical film on an exposed surface of the pressure-sensitive adhesive sheet formed by the manufacturing method according to any one of claims 1 to 19 to form an optical film with a pressure-sensitive adhesive sheet.

21. The method for producing an optical film with a pressure-sensitive adhesive sheet according to claim 20 , wherein the optical film comprises at least one film selected from the group consisting of a polarizing film and a retardation film.

22. A method for manufacturing an image display device, comprising bonding an optical film with a pressure-sensitive adhesive sheet formed by the manufacturing method according to claim 20 to an image display panel to form an image display device.

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