WO2024122316A1 - Set for image display panels, and image display panel - Google Patents

Set for image display panels, and image display panel Download PDF

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Publication number
WO2024122316A1
WO2024122316A1 PCT/JP2023/041550 JP2023041550W WO2024122316A1 WO 2024122316 A1 WO2024122316 A1 WO 2024122316A1 JP 2023041550 W JP2023041550 W JP 2023041550W WO 2024122316 A1 WO2024122316 A1 WO 2024122316A1
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meth
image display
adhesive sheet
optical laminate
test
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PCT/JP2023/041550
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French (fr)
Japanese (ja)
Inventor
一晃 米澤
寛大 小野
智之 木村
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日東電工株式会社
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Publication of WO2024122316A1 publication Critical patent/WO2024122316A1/en

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  • the present invention relates to a set for an image display panel and an image display panel.
  • image display devices such as liquid crystal display devices and electroluminescence (EL) display devices
  • an image display panel in which an image display cell, such as a liquid crystal cell or an EL light-emitting element, is laminated with an optical laminate including a polarizing film and an adhesive sheet.
  • the adhesive sheet is mainly used to bond between the films included in the optical laminate, and to bond the image display cell to the optical laminate.
  • Patent Document 1 discloses the addition of an antistatic agent to the adhesive sheet in order to prevent the image display device from becoming charged.
  • an image display device When an image display device is used in an environment where static electricity is particularly likely to occur, such as the inside of a vehicle where other electronic devices are present in the vicinity, it is necessary to sufficiently suppress charging of the image display device. From the perspective of sufficiently suppressing charging of the image display device, it is possible to use an image display panel in which a conductive structure is arranged on the side of the optical laminate.
  • the conductive structure can be formed by applying a conductive paste to the side of the optical laminate and curing it as necessary.
  • image display panels equipped with a conductive structure formed from a conductive paste tend to show a significant decrease in their antistatic performance when exposed to a high-temperature, high-humidity environment.
  • the present invention aims to provide a set for an image display panel that is suitable for producing an image display panel in which a conductive structure is formed on the side surface of an optical laminate, and in which the antistatic performance is unlikely to deteriorate even when exposed to a high-temperature, high-humidity environment.
  • the present invention relates to A set for an image display panel comprising an optical laminate having a polarizing film and an adhesive sheet, and a conductive paste,
  • the conductive paste is applied to a portion of the side surface of the optical laminate where the dimensional change amount determined by the following Test 1 is 80 ⁇ m or less to form a conductive structure,
  • the conductive paste has a breaking elongation of 5% or more as determined by the following Test 2.
  • Test 1 The optical laminate is attached to non-alkali glass via the pressure-sensitive adhesive sheet, and is subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH. The amount of dimensional change in the planar direction of the optical laminate before and after the heat treatment is determined.
  • Test 2 A flat film having a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
  • the present invention relates to an image display cell;
  • An optical laminate including a polarizing film and a pressure-sensitive adhesive sheet;
  • a conductive structure formed from a conductive paste and in contact with a portion of the side surface of the optical laminate where the dimensional change amount determined by the following Test 1 is 80 ⁇ m or less; Equipped with The conductive paste has a breaking elongation of 5% or more as determined by the following Test 2, and the image display panel is provided.
  • Test 1 The optical laminate is attached to non-alkali glass via the pressure-sensitive adhesive sheet, and is subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH.
  • Test 2 A flat film having a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
  • the present invention provides a set for an image display panel that is suitable for producing an image display panel in which a conductive structure is formed on the side surface of an optical laminate, and in which antistatic performance is unlikely to deteriorate even when exposed to a high-temperature, high-humidity environment.
  • FIG. 1 is a cross-sectional view illustrating an example of an optical laminate of the present invention.
  • FIG. 1 is a diagram for explaining the amount of dimensional change of the optical laminate when the heat treatment in Test 1 is performed.
  • FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention.
  • FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention.
  • FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention.
  • FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention.
  • FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention.
  • FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention.
  • FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention.
  • 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention.
  • 1 is a scanning electron microscope (SEM) image showing the surface of the image display panel of Example 1 after the heat treatment.
  • 11 is a SEM image showing the surface of the image display panel of Example 2 after the heat treatment.
  • 11 is a SEM image showing the surface of the image display panel of Comparative Example 1 after the heat treatment.
  • 11 is a SEM image showing the surface of the image display panel of Comparative Example 2 after the heat treatment.
  • the set for an image display panel comprises: A set for an image display panel comprising an optical laminate having a polarizing film and an adhesive sheet, and a conductive paste,
  • the conductive paste is applied to a portion of the side surface of the optical laminate where the dimensional change amount determined by the following Test 1 is 80 ⁇ m or less to form a conductive structure,
  • the conductive paste has a breaking elongation of 5% or more as determined by the following Test 2.
  • Test 1 The optical laminate is attached to non-alkali glass via the pressure-sensitive adhesive sheet, and is subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH.
  • Test 2 A flat film having a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
  • the breaking elongation is 25% or more.
  • the conductive paste contains a metal and a binder.
  • the binder includes at least one selected from the group consisting of polyester resin and silicone resin.
  • the binder is substantially free of epoxy resin.
  • the metal includes silver.
  • the polarizing film has two protective films and a polarizer disposed between the two protective films.
  • the thickness of the polarizer is 6 ⁇ m or more.
  • the pressure-sensitive adhesive sheet is formed from a pressure-sensitive adhesive composition containing a (meth)acrylic polymer (A).
  • the (meth)acrylic polymer (A) has a constituent unit derived from an ether group-containing monomer.
  • the adhesive composition further comprises an antistatic agent.
  • the pressure-sensitive adhesive sheet has a storage modulus G' at 25° C. of 9.0 ⁇ 10 4 Pa or more.
  • the adhesive sheet is in direct contact with the polarizing film.
  • An image display panel comprises: an image display cell; An optical laminate including a polarizing film and a pressure-sensitive adhesive sheet; A conductive structure formed from a conductive paste and in contact with a portion of the side surface of the optical laminate where the dimensional change amount determined by the following Test 1 is 80 ⁇ m or less; Equipped with The conductive paste has a breaking elongation of 5% or more as determined by the following Test 2.
  • Test 1 The optical laminate is attached to non-alkali glass via the pressure-sensitive adhesive sheet, and is subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH.
  • Test 2 A flat film having a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
  • the image display panel according to the fourteenth aspect has a built-in touch sensing function.
  • the image display panel set of this embodiment includes an optical laminate and a conductive paste.
  • FIG. 1 shows an example of an optical laminate that may be included in the image display panel set of this embodiment.
  • the optical laminate 10 of FIG. 1 has a polarizing film 2 and an adhesive sheet 1, and is composed of, for example, only the adhesive sheet 1 and the polarizing film 2.
  • the adhesive sheet 1 is in direct contact with the polarizing film 2.
  • the optical laminate 10 may include other members (e.g., an anchor layer or a conductive layer) other than the adhesive sheet 1 and the polarizing film 2, and the other members may be disposed between the adhesive sheet 1 and the polarizing film 2.
  • the optical laminate 10 can be attached to an object (e.g., an image display cell) via the adhesive sheet 1, and can be used as a polarizing film with an adhesive sheet.
  • the optical laminate 10 is, for example, sheet-like and has a pair of opposing main surfaces 10a and 10b and a side surface 10c.
  • the conductive paste is applied to a portion of the side surface 10c of the optical laminate 10 where the dimensional change amount determined by the following test 1 is 80 ⁇ m or less to form a conductive structure.
  • the conductive paste applied to the above portion may be cured as necessary.
  • Test 1 The optical laminate 10 is attached to non-alkali glass via the adhesive sheet 1, and heat-treated for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH. The amount of dimensional change in the planar direction of the optical laminate 10 before and after the heat treatment is determined.
  • Test 1 is carried out in detail by the following method.
  • the optical laminate 10 is prepared.
  • the optical laminate 10 is, for example, rectangular in plan view, with a length of 50 to 1500 mm and a width of 50 to 1500 mm.
  • FIG. 2 is an example of a plan view of the vicinity of the end of the optical laminate 10.
  • the outer edge of the optical laminate 10 before the heat treatment is performed is shown by a solid line.
  • the optical laminate 10 has, for example, a rectangular shape with chamfered corners in plan view.
  • the side surface 10c of the optical laminate 10 has, for example, a portion S1 extending in the absorption axis direction of the polarizing film 2, a portion S2 extending in the slow axis direction of the polarizing film 2, and a portion S3 that defines the chamfered corners.
  • the absorption axis direction and the slow axis direction of the polarizing film 2 are usually perpendicular to each other.
  • the optical laminate 10 is attached to the alkali-free glass via the adhesive sheet 1.
  • the alkali-free glass is glass that does not substantially contain alkali components (alkali metal oxides), and more specifically, the weight ratio of the alkali components in the glass is, for example, 1000 ppm or less, and even 500 ppm or less.
  • the alkali-free glass is, for example, in the form of a plate, and has a thickness of 0.5 mm or more.
  • the optical laminate 10 is attached to the alkali-free glass, for example, by overlapping the entire surface of the optical laminate 10 on the alkali-free glass and pressing them together by moving a 2 kg roller back and forth once.
  • the optical laminate 10 is placed in an environment with a temperature of 85°C and a humidity of 85% RH for 240 hours to perform a heat treatment. At this time, the optical laminate 10 usually shrinks in the planar direction.
  • the outer edge of the optical laminate 10 after the heat treatment is shown by a dashed line.
  • L1 corresponds to the amount of dimensional change (amount of shrinkage) in the planar direction of portion S1 before and after the heat treatment
  • L2 corresponds to the amount of dimensional change (amount of shrinkage) in the planar direction of portion S2 before and after the heat treatment
  • L3 corresponds to the amount of dimensional change (amount of shrinkage) in the planar direction of portion S3 before and after the heat treatment.
  • the dimensional changes L1 to L3 can be determined by microscopic observation.
  • the shrinkage of the optical laminate 10 usually tends to occur more strongly in the absorption axis direction of the polarizing film 2 than in the slow axis direction of the polarizing film 2. Therefore, the dimensional change amount L1 ( ⁇ m) of portion S1, the dimensional change amount L2 ( ⁇ m) of portion S2, and the dimensional change amount L3 ( ⁇ m) of portion S3 satisfy the relationship L2>L3>L1, for example.
  • the dimensional change L1 of portion S1 is 80 ⁇ m or less, and that a conductive paste is applied to portion S1 to form a conductive structure.
  • the conductive paste may be applied to the entire portion S1, or to a part of portion S1.
  • the dimensional change L1 is 80 ⁇ m or less
  • the dimensional change L2 of portion S2 and the dimensional change L3 of portion S3 may each be greater than 80 ⁇ m, but may also be 80 ⁇ m or less.
  • a conductive structure can be formed by applying a conductive paste to at least one of portions S1 to S3.
  • the dimensional changes L1 to L3 may be 70 ⁇ m or less, 60 ⁇ m or less, 50 ⁇ m or less, 40 ⁇ m or less, or even 35 ⁇ m or less.
  • the lower limit of the dimensional changes L1 to L3 is not particularly limited, and may be, for example, 10 ⁇ m or more, 20 ⁇ m or more, or even 30 ⁇ m or more.
  • the ratio L1/L2 of the dimensional change amount L1 ( ⁇ m) to the dimensional change amount L2 ( ⁇ m) is not particularly limited and may be, for example, less than 0.8, 0.7 or less, or even 0.6 or less.
  • the ratio L1/L2 is less than 0.8, the conductive structure formed by applying the conductive paste to the portion S1 is likely to maintain adhesion with the portion S1.
  • the lower limit of the ratio L1/L2 is not particularly limited and is, for example, 0.4.
  • the conductive paste has a breaking elongation of 5% or more as determined by the following Test 2.
  • Test 2 A flat film with a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
  • the method for producing the flat membrane is not particularly limited.
  • the flat membrane can be produced by applying a conductive paste to a substrate and curing it.
  • the conductive paste can be cured, for example, by heat treatment in an environment of 60°C to 150°C for 15 minutes to 5 hours.
  • test piece (dumbbell-shaped No. 1) is specified, for example, in JIS K6251:2017.
  • a tensile tester for example, the "Autograph AG-10G" tensile tester manufactured by Shimadzu Corporation can be used. The tensile test is performed by pulling the test piece in the longitudinal direction.
  • the breaking elongation determined by Test 2 is preferably 10% or more, more preferably 15% or more, 20% or more, 25% or more, or even 30% or more.
  • the upper limit of the breaking elongation is not particularly limited, and is, for example, 100% or less.
  • the conductive paste is applied to the portion of the side surface 10c of the optical laminate 10 where the dimensional change determined by Test 1 is 80 ⁇ m or less to form a conductive structure. Furthermore, the breaking elongation determined by Test 2 for the conductive paste is 5% or more. In an image display device or image display panel manufactured from a set that satisfies these requirements, even when exposed to a high temperature and high humidity environment, breakage is unlikely to occur between the conductive structure and the optical laminate, and as a result, antistatic performance tends not to deteriorate.
  • the adhesive sheet 1 is a layer containing an adhesive.
  • the adhesive contained in the adhesive sheet 1 are rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, polyvinylpyrrolidone-based adhesives, polyacrylamide-based adhesives, and cellulose-based adhesives.
  • the adhesive may be an acrylic adhesive, which has excellent optical transparency, appropriate adhesive properties such as wettability, cohesiveness, and adhesiveness, and is also excellent in weather resistance, heat resistance, and the like.
  • the adhesive sheet 1 may be an acrylic adhesive sheet.
  • the adhesive sheet 1, which is an acrylic adhesive sheet, will be described below.
  • the adhesive sheet 1 is formed from an adhesive composition.
  • the adhesive composition contains, for example, a (meth)acrylic polymer (A) and may further contain an antistatic agent.
  • the content of the (meth)acrylic polymer (A) in the adhesive composition may be 50% by weight or more, 60% by weight or more, 70% by weight or more, or even 80% by weight or more.
  • (meth)acrylic means acrylic and methacrylic.
  • (Meth)acrylate means acrylate and methacrylate.
  • the adhesive composition may be a photocurable composition containing a monomer group containing a (meth)acrylic monomer and/or a partial polymer of the monomer group. Examples of the (meth)acrylic monomer include those described below for the (meth)acrylic polymer (A).
  • the (meth)acrylic polymer (A) may have, for example, a structural unit derived from an alkyl (meth)acrylate, or may have the structural unit as a main component.
  • the number of carbon atoms of the alkyl group contained in the alkyl (meth)acrylate for forming the main skeleton of the (meth)acrylic polymer (A) is not particularly limited, and is, for example, 1 to 18.
  • the alkyl group may be linear, branched, or cyclic.
  • alkyl group examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group, a hexyl group, a cyclohexyl group, a heptyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group, a decyl group, an isodecyl group, a dodecyl group, an isomyristyl group, a lauryl group, a tridecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group.
  • the alkyl (meth)acrylate may be used alone or in combination.
  • the average number of carbon atoms of the alkyl group is preferably
  • the content of the structural units derived from alkyl (meth)acrylate is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, and even more preferably 80% by weight or more, from the viewpoint of improving the adhesiveness of the pressure-sensitive adhesive sheet.
  • the content of the structural units in the (meth)acrylic polymer (A) may be less than 50% by weight, 30% by weight or less, or even 10% by weight or less, depending on the circumstances.
  • examples of monomers constituting the (meth)acrylic polymer (A) include copolymerizable monomers such as ether group-containing monomers, carboxyl group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, and aromatic ring-containing monomers.
  • the copolymerizable monomers can be used alone or in combination.
  • the (meth)acrylic polymer (A) preferably contains a structural unit derived from an ether group-containing monomer.
  • the ether group-containing monomer is a compound that contains an ether group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group.
  • the ether group-containing monomer preferably includes an alkoxy group-containing monomer.
  • the alkoxy group-containing monomer is, for example, an alkylene oxide adduct represented by the following formula (1).
  • R 1 in formula (1) is a hydrogen atom or a methyl group.
  • R 2 in formula (1) is an alkyl group.
  • the alkyl group may be linear or branched.
  • R 2 is preferably a linear alkyl group. Examples of R 2 are a methyl group and an ethyl group.
  • n in formula (1) is an integer of 1 to 30, preferably an integer of 1 to 12, and may be an integer of 1 to 5.
  • alkylene oxide adduct shown in formula (1) examples include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and methoxypolyethylene glycol (meth)acrylate.
  • the alkoxy group-containing monomer preferably includes 2-methoxyethyl acrylate (MEA).
  • the ether group-containing monomer is not limited to the alkylene oxide adducts described above.
  • the ether group-containing monomer may have a ring structure, and the ring structure may have an ether group.
  • the ring structure may not contain functional groups other than the ether group.
  • Examples of ring structures having an ether group include a tetrahydrofuran ring and a dioxane ring.
  • Examples of ether group-containing monomers having a ring structure are cyclic trimethylolpropane formal (meth)acrylate and tetrahydrofurfuryl (meth)acrylate.
  • the content of the constituent units derived from the ether group-containing monomer is not particularly limited, and may be, for example, 25% by weight or more, preferably 30% by weight or more, and may be 40% by weight or more, 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, or even 90% by weight or more.
  • the upper limit of the content is, for example, 99% by weight or less, and in some cases may be 80% by weight or less, or 70% by weight or less.
  • Carboxyl group-containing monomers are compounds that contain a carboxyl group in their structure and also contain a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group.
  • carboxyl group-containing monomers include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid.
  • acrylic acid is preferred from the viewpoints of copolymerizability, cost, and improving the adhesive properties of the adhesive sheet 1.
  • the constituent units derived from the carboxyl group-containing monomer have high reactivity with the crosslinking agent, and contribute to improving the cohesiveness and heat resistance of the adhesive sheet 1.
  • the constituent units derived from the carboxyl group-containing monomer are also suitable for achieving both durability and reworkability in the adhesive sheet 1.
  • the content of the constituent units derived from the carboxyl group-containing monomer is not particularly limited, and is, for example, 10% by weight or less, and is preferably 0.01 to 8% by weight, 0.05 to 6% by weight, or even 0.1 to 5% by weight.
  • the content of the constituent units derived from the carboxyl group-containing monomer is 0.01% by weight or more, the durability of the adhesive sheet 1 tends to improve.
  • the content is 10% by weight or less, the reworkability of the adhesive sheet 1 tends to improve.
  • Hydroxyl-containing monomers are compounds that contain hydroxyl groups in their structure and polymerizable unsaturated double bonds such as (meth)acryloyl groups and vinyl groups.
  • hydroxyl-containing monomers include hydroxyl-containing alkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate; and hydroxyl-containing cycloalkyl (meth)acrylates such as (4-hydroxymethylcyclohexyl)-methylacrylate.
  • 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred from the standpoint of durability.
  • the structural units derived from hydroxyl group-containing monomers are highly reactive with crosslinking agents and contribute to improving the cohesiveness and heat resistance of the adhesive sheet 1.
  • the structural units derived from hydroxyl group-containing monomers are also suitable for improving the reworkability of the adhesive sheet 1.
  • the content of the structural units derived from hydroxyl group-containing monomers is not particularly limited, and is, for example, 3% by weight or less, and is preferably 0.01 to 3% by weight, 0.1 to 2% by weight, or even 0.2 to 2% by weight.
  • the content of the structural units derived from hydroxyl group-containing monomers is 0.01% by weight or more, the reactivity with the crosslinking agent is improved, and the durability and adhesive properties of the adhesive sheet 1 also tend to be improved. Furthermore, from the viewpoint of the durability of the adhesive sheet 1, the content of the structural units derived from hydroxyl group-containing monomers is preferably 3% by weight or less.
  • An amide group-containing monomer is a compound that contains an amide group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group.
  • the amide group-containing monomer include acrylamide-based monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropylacrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylol-N-propane(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, and mercaptoethyl(meth)acrylamide; N-acryloyl heterocyclic monomers such as N-(meth)acryl
  • the content of the structural unit derived from the amide group-containing monomer is preferably 10% by weight or less, and more preferably 5% by weight or less, from the viewpoint of the anchoring force between the polarizing film 2 and the adhesive sheet 1.
  • the content of the structural unit derived from the amide group-containing monomer is preferably 0.1% by weight or more, and more preferably 0.3% by weight or more, and even more preferably 0.5% by weight or more, from the viewpoint of suppressing an increase in the surface resistance value of the adhesive sheet 1 over time in a humid environment or the like.
  • the constituent units derived from the amide group-containing monomer are suitable for improving the compatibility between the (meth)acrylic polymer (A) and the antistatic agent (particularly an ionic compound). By improving this compatibility, it tends to be possible to suppress the surface resistance value of the adhesive sheet 1 from increasing over time in a humid environment.
  • the constituent units derived from the amide group-containing monomer also tend to improve the durability of the adhesive sheet 1 against glass and transparent conductive layers (e.g., an ITO layer). This adhesive sheet 1 makes it easy to suppress the occurrence of peeling or lifting of the optical laminate 10 from the image display cell. Furthermore, the constituent units derived from the amide group-containing monomer tend to contribute to improving the durability of the adhesive sheet 1 in a humid environment.
  • the aromatic ring-containing monomer is a compound that contains an aromatic ring structure in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group.
  • aromatic rings include a benzene ring, a naphthalene ring, and a biphenyl ring.
  • the aromatic ring-containing monomer is preferably an aromatic ring-containing (meth)acrylate.
  • aromatic ring-containing (meth)acrylates examples include benzyl (meth)acrylate, phenyl (meth)acrylate, o-phenylphenol (meth)acrylate, phenoxy (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxypropyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide-modified nonylphenol (meth)acrylate, ethylene oxide-modified cresol (meth)acrylate, phenol ethylene oxide-modified (meth)acrylate, 2-hydroxy
  • acrylates include those having a benzene ring, such as 3-phenoxypropyl (meth)acrylate, methoxybenzyl (meth)acrylate, chlorobenzyl (meth)acrylate, cresyl (meth)acrylate, and polystyryl (meth)acrylate; those having a naphthalene ring, such as hydroxyethylated
  • the content of the structural unit derived from the aromatic ring-containing monomer is not particularly limited, and is, for example, 25% by weight or less, and preferably 3 to 25% by weight, 10 to 22% by weight, or even 14 to 20% by weight.
  • the content of the structural unit derived from the aromatic ring-containing monomer is 3% by weight or more, there is a tendency that display unevenness of the image display device can be suppressed.
  • the content is 25% by weight or less, there is a tendency that the durability of the adhesive sheet 1 can be improved.
  • other copolymerizing monomers having a polymerizable functional group containing an unsaturated double bond such as a (meth)acryloyl group or a vinyl group, can be used as the monomers constituting the (meth)acrylic polymer (A) in order to improve the adhesiveness and heat resistance of the adhesive sheet 1.
  • the other copolymerizing monomers can be used alone or in combination.
  • copolymerizable monomers include, for example, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; sulfonic acid group-containing monomers such as allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, and sulfopropyl (meth)acrylate; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; alkylaminoalkyl (meth)acrylates such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; methoxyethyl (meth)acrylate, ethoxyethyl alkoxyalkyl (meth)acrylates
  • examples of other copolymerizable monomers include polyfunctional monomers having two or more unsaturated double bonds, such as tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, polyester (meth)acrylate, epoxy (meth)acrylate, and urethane (meth)
  • the content of structural units derived from the other copolymerization monomers in the (meth)acrylic polymer (A) is preferably 10% by weight or less, more preferably 7% by weight or less, and even more preferably 5% by weight or less.
  • the weight average molecular weight of the (meth)acrylic polymer (A) is usually 300,000 to 4,000,000. From the viewpoint of durability, the weight average molecular weight of the (meth)acrylic polymer (A) is preferably 1,000,000 or more, and may be 1,500,000 or more. The weight average molecular weight of the (meth)acrylic polymer (A) may be 3,000,000 or less, and may be 2,000,000 or less. A weight average molecular weight of 300,000 or more is preferable from the viewpoint of heat resistance. If the weight average molecular weight is 4,000,000 or less, the adhesive sheet tends not to become hard and peeling does not occur easily.
  • the weight average molecular weight (Mw)/number average molecular weight (Mn), which means the molecular weight distribution, is preferably 1.8 to 10, more preferably 1.8 to 7, and even more preferably 1.8 to 5. From the viewpoint of durability, it is preferable that the molecular weight distribution (Mw/Mn) is 10 or less.
  • the weight average molecular weight and the molecular weight distribution (Mw/Mn) are measured by GPC (gel permeation chromatography) and calculated from the polystyrene equivalent.
  • the (meth)acrylic polymer (A) can be produced by known polymerization methods such as solution polymerization, radiation polymerization using electron beams or UV rays, bulk polymerization, emulsion polymerization, and other radical polymerizations.
  • the resulting (meth)acrylic polymer (A) may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.
  • solution polymerization for example, ethyl acetate, toluene, etc. are used as the polymerization solvent.
  • Solution polymerization is usually carried out under reaction conditions of about 50 to 70°C for about 5 to 30 hours, with a polymerization initiator added under a stream of inert gas such as nitrogen.
  • the polymerization initiator, chain transfer agent, emulsifier, etc. used in the radical polymerization are not particularly limited and can be appropriately selected and used.
  • the weight average molecular weight of the (meth)acrylic polymer (A) can be controlled by the amount of polymerization initiator and chain transfer agent used, reaction conditions, etc. Therefore, the amount of polymerization initiator and chain transfer agent used is appropriately adjusted depending on the composition.
  • polymerization initiators examples include azo initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane)dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis(2-methylpropionamidine)disulfate, 2,2'-azobis(N,N'-dimethyleneisobutylamidine), and 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate (e.g., VA-057 manufactured by Wako Pure Chemical Industries, Ltd.); persulfates such as potassium persulfate and ammonium persulfate; di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di- Peroxide-based initiators such as
  • the polymerization initiators can be used alone or in combination of two or more.
  • the total amount of polymerization initiator used is, for example, 0.005 to 1 part by weight, or may be 0.02 to 0.5 parts by weight, per 100 parts by weight of the monomer component.
  • chain transfer agents examples include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol.
  • the chain transfer agents can be used alone or in combination of two or more.
  • the total amount of chain transfer agent used is, for example, 0.1 parts by weight or less per 100 parts by weight of the monomer component.
  • the monomer group is irradiated with radiation such as electron beams or UV light to cause polymerization to proceed and form a (meth)acrylic polymer (A).
  • radiation polymerization is performed with electron beams, the use of a photopolymerization initiator is not particularly necessary.
  • a photopolymerization initiator may be used due to the advantage that the polymerization time can be shortened.
  • the photopolymerization initiators can be used alone or in combination of two or more types.
  • photopolymerization initiators examples include various photopolymerization initiators such as benzoin ether, acetophenone, ⁇ -ketol, photoactive oxime, benzoin, benzil, benzophenone, ketal, and thioxanthone.
  • the photopolymerization initiator is not limited to the above examples.
  • the amount of photopolymerization initiator used is, for example, 0.05 to 1.5 parts by weight, or may be 0.1 to 1 part by weight, per 100 parts by weight of the monomer component.
  • the antistatic agent is a material capable of imparting antistatic properties to the pressure-sensitive adhesive sheet 1.
  • examples of the antistatic agent include ionic surfactants, conductive polymers, conductive fine particles, and ionic compounds.
  • Ionic surfactants include, for example, cationic surfactants such as quaternary ammonium salts, phosphonium salts, and sulfonium salts; anionic surfactants such as carboxylic acid, sulfonate, sulfate, phosphate, and phosphite; amphoteric surfactants such as sulfobetaine, alkylbetaine, and alkylimidazolium betaine; and nonionic surfactants such as polyhydric alcohol derivatives, ⁇ -cyclodextrin clathrate compounds, sorbitan fatty acid monoesters, sorbitan fatty acid diesters, polyalkylene oxide derivatives, and amine oxides.
  • cationic surfactants such as quaternary ammonium salts, phosphonium salts, and sulfonium salts
  • anionic surfactants such as carboxylic acid, sulfonate, sulfate, phosphate, and pho
  • Conductive polymers include polyaniline, polythiophene, polypyrrole, and polyquinoxaline polymers. Among these, polyaniline and polythiophene, which easily function as water-soluble conductive polymers or water-dispersible conductive polymers, are preferred, with polythiophene being particularly preferred.
  • Conductive fine particles include, for example, metal oxide fine particles such as tin oxide, antimony oxide, indium oxide, and zinc oxide, with tin oxide fine particles being preferred.
  • Materials for tin oxide fine particles include, for example, tin oxide, antimony-doped tin oxide, indium-doped tin oxide, aluminum-doped tin oxide, tungsten-doped tin oxide, titanium oxide-cerium oxide-tin oxide composite, and titanium oxide-tin oxide composite.
  • the average particle size of the conductive fine particles is, for example, 1 to 100 nm, and preferably 2 to 50 nm.
  • the average particle size of the conductive fine particles means, for example, the particle size (d50) corresponding to 50% cumulative volume in the particle size distribution measured by a laser diffraction particle sizer or the like.
  • the antistatic agent preferably contains an ionic compound.
  • the ionic compound is preferably an ionic liquid.
  • the ionic compound examples include alkali metal salts and/or organic cation-anion salts.
  • the alkali metal salts include organic and inorganic salts of alkali metals.
  • the alkali metal salt is preferably an organic salt of an alkali metal.
  • the organic cation-anion salt means an organic salt containing an organic cation.
  • the anion contained in the organic cation-anion salt may be an organic anion or an inorganic anion.
  • the anion contained in the organic cation-anion salt is preferably an organic anion.
  • the organic cation-anion salt may be called an ionic liquid or an ionic solid.
  • alkali metal ions contained in the alkali metal salt include lithium ions, sodium ions, and potassium ions, with lithium ions being preferred.
  • Examples of anions contained in organic salts of alkali metals include CH3COO- , CF3COO- , CH3SO3- , CF3SO3- , ( CF3SO2 ) 3C- , C4F9SO3-, C3F7COO-, (CF3SO2 ) ( CF3CO ) N- , -O3S ( CF2 ) 3SO3- , ( CN ) 2N- , and anions represented by the following general formulas (a ) to ( d ).
  • the anion contained in the organic salt of an alkali metal preferably contains a fluorine atom.
  • the organic salt of an alkali metal functions as an ionic compound with excellent ion dissociation properties.
  • Examples of anions contained in inorganic salts of alkali metals include Cl- , Br- , I- , AlCl4-, Al2Cl7- , BF4- , PF6- , ClO4- , NO3- , AsF6- , SbF6- , NbF6- , TaF6- , ( FSO2 )2N- , and CO32- .
  • a (perfluoroalkylsulfonyl)imide represented by the above general formula (a) such as ( CF3SO2 ) 2N- or ( C2F5SO2 ) 2N- , is preferred, and a ( trifluoromethanesulfonyl )imide represented by ( CF3SO2 ) 2N- is particularly preferred.
  • Examples of the organic salt of an alkali metal include sodium acetate, sodium alginate, sodium ligninsulfonate, sodium toluenesulfonate , LiCF3SO3 , Li( CF3SO2 ) 2N , Li( C2F5SO2 ) 2N , Li( C4F9SO2 ) 2N , Li( CF3SO2)3C, KO3S(CF2)3SO3K, LiO3S(CF2)3SO3K, and the like.
  • LiCF3SO3, Li(CF3SO2 ) 2N , Li ( C2F5SO2 ) 2N , Li ( C4F9SO2 ) 2N , Li ( CF3SO2 ) 3C , LiO3S ( CF2 ) 3SO3K , and the like are preferably used .
  • the organic salt of an alkali metal is preferably Li(CF3SO2)2N , Li (C2F5SO2 ) 2N , or Li( C4F9SO2 ) 2N .
  • the organic salt of an alkali metal is preferably a fluorine-containing lithium imide salt, and more preferably a ( perfluoroalkylsulfonyl )imide lithium salt.
  • inorganic salts of alkali metals include lithium perchlorate and lithium iodide.
  • organic cations contained in the organic cation-anion salt include pyridinium cation, piperidinium cation, pyrrolidinium cation, cations having a pyrroline skeleton, cations having a pyrrole skeleton, imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation, pyrazolium cation, pyrazolinium cation, tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylphosphonium cation, etc.
  • Examples of anions contained in the organic cation-anion salt include Cl- , Br- , I- , AlCl4- , Al2Cl7- , BF4- , PF6- , ClO4- , NO3- , CH3COO- , CF3COO- , CH3SO3-, CF3SO3- , ( CF3SO2 ) 3C- , AsF6- , SbF6- , NbF6- , TaF6- , ( CN ) 2N- , C4F9SO3- , C3F7COO- , ( CF3SO2 ) ( CF3CO ) N- , ( FSO2 ) 2N- , -O3S ( CF2 ) 3SO3- , ( FSO2 ) 2N- and the anions represented by the above general formulas (a) to (d) are included.
  • the anion contained in the organic cation-anion salt preferably contains a fluorine atom.
  • the organic cation-anion salt functions as an ionic compound with excellent ion dissociation properties.
  • Ionic compounds are not limited to the above-mentioned alkali metal salts and organic cation-anion salts, but also include inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, and ammonium sulfate. Ionic compounds can be used alone or in combination.
  • the molecular weight of the cation is, for example, 210 or less, and preferably 150 or less, 110 or less, 50 or less, or even 10 or less, from the viewpoint of suppressing poor conduction in a high-temperature environment.
  • the smaller the molecular weight of the cation the less likely the adhesive sheet 1 is to become soft, and there is a tendency for poor conduction in a high-temperature environment to be suppressed.
  • the surface resistance value of the adhesive sheet 1 is more likely to decrease, and there is also a tendency for static electricity unevenness to be suppressed.
  • alkali metal salts containing these alkali metal ions as cations can be suitably used.
  • the alkali metal ion is preferably the lithium ion, which has the smallest molecular weight.
  • the ionic compound is preferably a lithium salt, and more preferably an organic salt of lithium. When using an organic cation-anion salt, it is preferable to use one of the above-mentioned cations that has a molecular weight of 210 or less.
  • Antistatic agents are not limited to the above-mentioned materials, and examples thereof include carbon materials such as acetylene black, ketjen black, natural graphite, and artificial graphite; titanium black; homopolymers of monomers having ion-conductive groups of cationic type such as quaternary ammonium salts, amphoteric type such as betaine compounds, anionic type such as sulfonates, or nonionic type such as glycerin, or copolymers of said monomers with other monomers; polymers having ion conductivity such as polymers having structural units derived from acrylate or methacrylate having quaternary ammonium bases; and alloys of hydrophilic polymers such as polyethylene methacrylate copolymers with acrylic resins (permanent antistatic agents).
  • carbon materials such as acetylene black, ketjen black, natural graphite, and artificial graphite
  • titanium black homopolymers of monomers having ion-conductive groups of cationic type such
  • the amount of the antistatic agent can be adjusted as appropriate according to the desired surface resistance value of the adhesive sheet 1, and is, for example, 0.05 to 20 parts by weight per 100 parts by weight of the (meth)acrylic polymer (A).
  • the amount of the antistatic agent is preferably 0.05 parts by weight or more per 100 parts by weight of the (meth)acrylic polymer (A), more preferably 0.1 parts by weight or more, and even more preferably 0.5 parts by weight or more.
  • the amount of the antistatic agent is preferably 20 parts by weight or less per 100 parts by weight of the (meth)acrylic polymer (A), and even more preferably 10 parts by weight or less.
  • the adhesive composition may further contain a crosslinking agent.
  • a crosslinking agent an organic crosslinking agent, a polyfunctional metal chelate, etc. can be used.
  • organic crosslinking agent for example, an isocyanate crosslinking agent, a peroxide crosslinking agent, an epoxy crosslinking agent, an imine crosslinking agent, etc. can be mentioned.
  • a polyvalent metal atom is covalently bonded or coordinately bonded to an organic compound.
  • the organic compound that is covalently bonded or coordinately bonded contains, for example, an oxygen atom, etc., and preferably includes an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, a ketone compound, etc.
  • the crosslinking agent can be used alone or in combination.
  • crosslinking agent an isocyanate-based crosslinking agent and/or a peroxide-based crosslinking agent is preferred.
  • isocyanate-based crosslinking agent a compound having at least two isocyanate groups (isocyanate compound) can be used.
  • the number of isocyanate groups contained in the isocyanate compound is preferably 3 or more.
  • the upper limit of the number of isocyanate groups is not particularly limited, and is, for example, 5.
  • isocyanate compounds are aromatic isocyanate compounds, alicyclic isocyanate compounds, and aliphatic isocyanate compounds.
  • isocyanate-based crosslinking agent a compound that can self-polymerize by reacting with water is preferable.
  • aromatic isocyanate compounds are phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenylether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate.
  • alicyclic isocyanate compounds are 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated tetramethylxylylene diisocyanate.
  • aliphatic isocyanate compounds are trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.
  • the isocyanate-based crosslinking agent may be a polymer (dimer, trimer, pentamer, etc.) of the above isocyanate compounds, an adduct obtained by adding the compound to a polyhydric alcohol such as trimethylolpropane, a urea-modified compound, a biuret-modified compound, an allophanate-modified compound, an isocyanurate-modified compound, a carbodiimide-modified compound, or a urethane prepolymer obtained by adding the compound to a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol, etc.
  • a polyhydric alcohol such as trimethylolpropane
  • a urea-modified compound such as trimethylolpropane
  • a urea-modified compound such as trimethylolpropane
  • a urea-modified compound such
  • the isocyanate-based crosslinking agent is preferably an aromatic isocyanate compound and its derivatives, more preferably tolylene diisocyanate and its derivatives, in other words, a tolylene diisocyanate-based (TDI-based) crosslinking agent.
  • the TDI-based crosslinking agent is more suitable than xylylene diisocyanate and its derivatives, in other words, a xylylene diisocyanate-based (XDI-based) crosslinking agent.
  • the isocyanate-based crosslinking agent may contain an adduct of a polyhydric alcohol and tolylene diisocyanate as a TDI-based crosslinking agent.
  • a specific example of the adduct is a trimethylolpropane/tolylene diisocyanate trimer adduct.
  • Isocyanate-based crosslinking agents may be used alone or in combination of two or more types.
  • Any peroxide can be used as long as it generates radical active species when heated or irradiated with light and promotes crosslinking of the (meth)acrylic polymer (A) of the adhesive composition. Taking into consideration workability and stability, it is preferable to use a peroxide with a 1-minute half-life temperature of 80°C to 160°C, and more preferably a peroxide with a 1-minute half-life temperature of 90°C to 140°C.
  • Peroxides include, for example, di(2-ethylhexyl) peroxydicarbonate (1-minute half-life temperature: 90.6°C), di(4-t-butylcyclohexyl) peroxydicarbonate (1-minute half-life temperature: 92.1°C), di-sec-butyl peroxydicarbonate (1-minute half-life temperature: 92.4°C), t-butyl peroxyneodecanoate (1-minute half-life temperature: 103.5°C), t-hexyl peroxypivalate (1-minute half-life temperature: 109.1°C), t-butyl peroxypivalate (1-minute half-life temperature: 110.3°C), dilauroyl peroxide ( 1-minute half-life temperature: 116.4°C), di-n-octanoyl peroxide (1-minute half-life temperature: 117.4°C), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexan
  • di(4-t-butylcyclohexyl) peroxydicarbonate (1-minute half-life temperature: 92.1°C)
  • dilauroyl peroxide (1-minute half-life temperature: 116.4°C)
  • dibenzoyl peroxide (1-minute half-life temperature: 130.0°C), etc. are particularly preferred because of their excellent crosslinking reaction efficiency.
  • the amount of crosslinking agent blended is, for example, 3 parts by weight or less, preferably 0.01 to 3 parts by weight, more preferably 0.02 to 2 parts by weight, and even more preferably 0.03 to 1 part by weight, relative to 100 parts by weight of the (meth)acrylic polymer (A).
  • the amount of crosslinking agent blended is 0.01 part by weight or more, the adhesive sheet 1 is sufficiently crosslinked, and there is a tendency for the durability and adhesive properties to be improved.
  • the amount of crosslinking agent blended is 3 parts by weight or less, there is a tendency for the adhesive sheet 1 to be prevented from becoming too hard and reducing its durability.
  • the pressure-sensitive adhesive composition may further contain a silane coupling agent.
  • a silane coupling agent tends to improve the durability of the pressure-sensitive adhesive sheet 1.
  • 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-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl- ⁇ -aminopropyltrimethoxysilane; (me
  • the silane coupling agent may have multiple alkoxysilyl groups in the molecule.
  • Specific examples of such silane coupling agents include X-41-1053, X-41-1059A, X-41-1056, X-41-1805, X-41-1818, X-41-1810, and X-40-2651 manufactured by Shin-Etsu Chemical Co., Ltd.
  • These silane coupling agents are not only less likely to volatilize, but also tend to effectively improve the durability of the adhesive sheet 1. In particular, the durability of the adhesive sheet 1 is likely to be improved even when a transparent conductive layer (e.g., an ITO layer) that has a lower reactivity with alkoxysilyl groups compared to glass is used as the adherend.
  • a transparent conductive layer e.g., an ITO layer
  • the silane coupling agent having multiple alkoxysilyl groups in the molecule preferably has an epoxy group in the molecule, and more preferably has multiple epoxy groups. According to a silane coupling agent having multiple alkoxysilyl groups and an epoxy group in the molecule, the durability of the adhesive sheet 1 is more likely to be improved even when a transparent conductive layer is used as the adherend.
  • Specific examples of such silane coupling agents include X-41-1053, X-41-1059A, and X-41-1056 manufactured by Shin-Etsu Chemical Co., Ltd., and X-41-1056, which contains a large amount of epoxy groups, is particularly preferred.
  • the silane coupling agent may be used alone or in a mixture of two or more kinds.
  • the amount of the silane coupling agent is, for example, 5 parts by weight or less relative to 100 parts by weight of the (meth)acrylic polymer (A), and is preferably 0.001 to 5 parts by weight, 0.01 to 1 part by weight, 0.02 to 1 part by weight, or even 0.05 to 0.6 parts by weight.
  • the adhesive composition may further contain additives other than those mentioned above.
  • additives include polyether compounds having reactive silyl groups, polyalkylene glycols (e.g., polypropylene glycols), colorants, powders such as pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antiaging agents, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particles, foils, solvents, etc.
  • a redox system containing a reducing agent may be used.
  • the amount of these additives may be, for example, 5 parts by weight or less, 3 parts by weight or less, or even 1 part by weight or less, relative to 100 parts by weight of the (meth)acrylic polymer (A).
  • the thickness of the pressure-sensitive adhesive sheet 1 is not particularly limited and is, for example, about 1 to 100 ⁇ m, preferably 2 to 50 ⁇ m, more preferably 2 to 40 ⁇ m, and even more preferably 5 to 35 ⁇ m. From the viewpoint of ensuring a sufficient contact area with the conductive structure, the thickness of the pressure-sensitive adhesive sheet 1 may be 5 to 100 ⁇ m, 5 to 50 ⁇ m, or even 10 to 35 ⁇ m.
  • the storage modulus G' of the pressure-sensitive adhesive sheet 1 at 25°C is not particularly limited, and may be, for example, 1.0 x 103 Pa or more, 1.0 x 104 Pa or more, 3.0 x 104 Pa or more, 5.0 x 104 Pa or more, 7.0 x 104 Pa or more, 9.0 x 104 Pa or more, or even 1.0 x 105 Pa or more.
  • the upper limit of the storage modulus G' of the pressure-sensitive adhesive sheet 1 at 25°C is not particularly limited, and is, for example, 1.0 x 107 Pa or less.
  • a pressure-sensitive adhesive sheet 1 having a high storage modulus G' is suitable for reducing the dimensional change of the optical laminate 10 in the above test 1.
  • the storage modulus G' of the adhesive sheet 1 at 25°C can be determined by the following method. First, a measurement sample made of the material constituting the adhesive sheet 1 is prepared. The shape of the measurement sample is disk-shaped. The measurement sample has a bottom diameter of 8 mm and a thickness of 1 mm. The measurement sample may be a disk-shaped punched out laminate in which a plurality of adhesive sheets 1 are laminated. Next, dynamic viscoelasticity measurement is performed on the measurement sample. For example, "ARES-G2" manufactured by TA Instruments can be used for the dynamic viscoelasticity measurement. The storage modulus G' of the adhesive sheet 1 at 25°C can be determined from the results of the dynamic viscoelasticity measurement. The conditions for the dynamic viscoelasticity measurement are as follows. Measurement conditions Frequency: 1Hz Deformation mode: Torsion Measurement temperature: -70°C to 150°C Heating rate: 5° C./min
  • the surface resistance of the pressure-sensitive adhesive sheet 1 is, for example, 1.0 ⁇ 10 7 ⁇ / ⁇ to 1.0 ⁇ 10 12 ⁇ / ⁇ , and preferably 1.0 ⁇ 10 8 ⁇ / ⁇ to 1.0 ⁇ 10 11 ⁇ / ⁇ .
  • the surface resistance of the pressure-sensitive adhesive sheet 1 can be measured in accordance with the method specified in JIS K6911:1995.
  • the polarizing film 2 includes, for example, a polarizer and a protective film (transparent protective film).
  • the protective film is arranged, for example, in contact with the main surface (the surface having the widest area) of the polarizer.
  • the polarizing film 2 may have two protective films, and the polarizer may be arranged between the two protective films. When the polarizer is arranged between the two protective films, discoloration of the polarizer in a high-temperature and high-humidity environment tends to be suppressed.
  • 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 have been uniaxially stretched after adsorbing dichroic substances such as iodine and dichroic dyes; and polyene-based oriented films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride.
  • Polarizers are typically made of polyvinyl alcohol films (polyvinyl alcohol films include partially saponified ethylene-vinyl acetate copolymer films) and iodine.
  • the iodine content in the polarizer may be, for example, 6.0% by weight or less, 5.0% by weight or less, or even 4.0% by weight or less, from the viewpoint of heat resistance.
  • the iodine content may be, for example, 1.0% by weight or more, 1.5% by weight or more, or even 2.0% by weight or more, from the viewpoint of optical properties.
  • a polarizer with an iodine content of 6.0% by weight or less tends to suppress dimensional changes in a high-temperature and high-humidity environment.
  • the thickness of the polarizer is generally 80 ⁇ m or less, and may be 50 ⁇ m or less, 30 ⁇ m or less, 25 ⁇ m or less, 22 ⁇ m or less, or even 20 ⁇ m or less. If the thickness of the polarizer is small, the amount of dimensional change of the optical laminate 10 in the above test 1 tends to decrease.
  • the lower limit of the polarizer thickness is not particularly limited, and may be, for example, 1 ⁇ m or more, 5 ⁇ m or more, 6 ⁇ m or more, 10 ⁇ m or more, or even 15 ⁇ m or more.
  • thermoplastic resins excellent in transparency, mechanical strength, thermal stability, moisture blocking property, isotropy, etc.
  • 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 resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof.
  • 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 resins), polyarylate resins, polystyrene resins, poly
  • the material of the protective film may be a thermosetting resin or an ultraviolet-curing resin such as a (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone.
  • the materials of the two protective films may be the same or different from each other.
  • a protective film made of a thermoplastic resin may be attached to one main surface of the polarizer via an adhesive
  • a protective film made of a thermosetting resin or an ultraviolet-curing resin may be attached to the other main surface of the polarizer.
  • the protective film may contain one or more types of optional additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, color inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.
  • the material of the protective film is preferably a cellulose resin, a (meth)acrylic resin, or the like.
  • a (meth)acrylic resin having a lactone ring structure is preferable. Examples of (meth)acrylic resins having a lactone ring structure are described in JP-A Nos. 2000-230016, 2001-151814, 2002-120326, 2002-254544, and 2005-146084. Compared to (meth)acrylic resins, cellulose resins tend to be able to suppress cracks in the polarizer more effectively.
  • the thickness of the protective film can be determined as appropriate, but is generally around 10 to 200 ⁇ m, taking into consideration strength, ease of handling, thinness, etc.
  • the polarizer and protective film are laminated via an intervening layer such as an adhesive sheet, a pressure sensitive adhesive sheet, or an undercoat layer (primer layer). It is preferable that the polarizer and protective film are laminated without gaps by the intervening layer.
  • the intervening layer is preferably an adhesive sheet.
  • the adhesive that forms the adhesive sheet as long as it is optically transparent, and examples of the adhesive that can be used include various types of adhesives such as water-based, solvent-based, hot melt, radical curing, and cationic curing, with water-based adhesives or radical curing adhesives being preferred.
  • the polarizing film 2 may have a retardation film, a diffusion film, etc., instead of a protective film.
  • retardation films include those having a front retardation of 40 nm or more and/or a thickness direction retardation of 80 nm or more.
  • the front retardation is usually adjusted to a range of 40 to 200 nm
  • the thickness direction retardation is adjusted to a range of 80 to 300 nm. Since the retardation film also functions as a protective film, when the polarizing film 2 includes a retardation film, the polarizing film 2 can be made thinner.
  • the optical laminate 10 can be produced, for example, by the following method. First, the above-mentioned pressure-sensitive adhesive composition is applied onto a release liner and dried to form a pressure-sensitive adhesive sheet 1. The pressure-sensitive adhesive sheet 1 is transferred to a polarizing film 2 to produce the optical laminate 10. Note that the optical laminate 10 can also be produced by applying the pressure-sensitive adhesive composition onto a polarizing film 2 and drying to form the pressure-sensitive adhesive sheet 1.
  • the conductive paste is applied to a portion of the side surface 10c of the optical laminate 10 where the dimensional change amount determined by Test 1 is 80 ⁇ m or less to form a conductive structure. Furthermore, the conductive paste has a breaking elongation of 5% or more determined by Test 2. As long as these requirements are met, the conductive paste is not particularly limited.
  • the conductive paste contains, for example, a metal and a binder.
  • the conductive paste contains metal particles, and the metal particles are dispersed in the binder.
  • the metal functions as a conductive component. Examples of the metal include copper, silver, platinum, gold, aluminum, nickel, zinc, lithium, magnesium, and cobalt.
  • the metal it is preferable that the metal contains silver.
  • the metal content in the conductive paste is, for example, 40% by weight or more, and may be 50% by weight or more, or even 55% by weight or more. There is no particular upper limit to the metal content, and it is, for example, 70% by weight or less.
  • the binder includes, for example, a thermosetting resin.
  • thermosetting resins include polyester resin, silicone resin, and polyurethane resin. These resins are suitable for increasing the breaking elongation determined by Test 2. It is preferable that the binder includes, as the thermosetting resin, at least one selected from the group consisting of polyester resin and silicone resin.
  • the binder content in the conductive paste may be, for example, 30% by weight or more, 40% by weight or more, or even 50% by weight or more, from the viewpoint of durability of the conductive structure.
  • the upper limit of the binder content is not particularly limited, and is, for example, 60% by weight or less.
  • the binder contains an epoxy resin as a thermosetting resin, the breaking elongation determined by Test 2 tends to decrease. Therefore, it is preferable that the content of epoxy resin in the binder is low, for example, 1% by weight or less, and 0.1% by weight or less. It is preferable that the binder does not substantially contain epoxy resin.
  • the conductive paste preferably has high adhesion to the side surface 10c of the optical laminate 10 (specifically, the side surface of the pressure-sensitive adhesive sheet 1 or the side surface of the polarizing film 2).
  • the conductive paste preferably has an adhesion strength of 0.1 N/25 mm or more as determined by the following Test 3.
  • Test 3 A conductive paste is applied to non-alkali glass to prepare a flat film.
  • the optical laminate 10 is attached to the surface of the flat film via the adhesive sheet 1.
  • the optical laminate 10 is peeled off from the flat film at a peel angle of 90° and a peel speed of 300 mm/min. The force (adhesion force) required at this time is measured.
  • Test 3 is carried out by the following method.
  • a non-alkali glass e.g., Corning 1737
  • a conductive paste is applied to the non-alkali glass, and cured by heat treatment for 15 minutes to 5 hours in an environment of, for example, 60°C to 150°C to produce a flat film.
  • the optical laminate 10 (width 25 mm) is attached to the surface of the flat film via the adhesive sheet 1.
  • the optical laminate 10 is attached, for example, using a laminator.
  • the optical laminate 10 is adhered to the flat film by autoclaving for 15 minutes at 50°C and 5 atm.
  • the optical laminate 10 is peeled off from the flat film at a peel angle of 90° and a peel speed of 300 mm/min (measurement length 80 mm). At this time, the force required to peel the optical laminate 10 off the alkali-free glass is measured once every 0.5 s. The average value of the obtained measurements is specified as the adhesion strength (N/25 mm).
  • the adhesion strength may be 1 N/25 mm or more, or 5 N/25 mm or more.
  • the upper limit of the adhesion strength is not particularly limited, and is, for example, 20 N/25 mm or less.
  • the conductive paste is applied to the portion of the side surface 10c of the optical laminate 10 where the dimensional change determined by Test 1 is 80 ⁇ m or less to form a conductive structure.
  • the conductive paste applied to the above portion may be cured as necessary.
  • the conductive paste can be cured, for example, by heat treatment in an environment of 60°C to 150°C for 15 minutes to 5 hours.
  • FIG. 3A An example of the image display panel of this embodiment is shown in FIG. 3A.
  • the image display panel 100A of FIG. 3A includes an image display cell 30A, the optical laminate 10 described above, and a conductive structure 20.
  • the conductive structure 20 is formed from the conductive paste described above, and is in contact with a portion of the side surface 10c of the optical laminate 10 where the dimensional change amount determined by Test 1 is 80 ⁇ m or less.
  • the conductive paste has a breaking elongation determined by Test 2 of 5% or more.
  • An image display device including the image display panel 100A of this embodiment is less likely to break between the conductive structure 20 and the optical laminate 10 even when it is subjected to a high temperature and high humidity environment, and therefore tends to be less likely to have a reduced antistatic performance.
  • the optical laminate 10 is disposed, for example, on the viewing side of the image display cell 30A.
  • the optical laminate 10 is attached to the image display cell 30A via, for example, an adhesive sheet 1.
  • the conductive structure 20 is in contact with the portion of the side surface 10c of the optical laminate 10 where the dimensional change determined by Test 1 is 80 ⁇ m or less.
  • the conductive structure 20 may be in contact with the entire portion where the dimensional change is 80 ⁇ m or less, or may be in contact with a part of the portion. It is preferable that the conductive structure 20 is not in contact with the portion where the dimensional change is greater than 80 ⁇ m.
  • the conductive structure 20 is preferably in contact with at least the side surface of the adhesive sheet 1 among the side surfaces 10c of the optical laminate 10, and typically is in contact with both the side surface of the adhesive sheet 1 and the side surface of the polarizing film 2. A part of the conductive structure 20 may be in contact with the main surface 10a of the optical laminate 10 (specifically, the main surface of the polarizing film 2).
  • the conductive structure 20 extends, for example, in the thickness direction of the optical laminate 10, and one end thereof is in contact with the image display cell 30A.
  • the ratio of the area of the side 10c of the optical laminate 10 covered by the conductive structure 20 to the total area of the side 10c of the optical laminate 10 is, for example, 1% or more, and preferably 3% or more. This ratio may be 99% or less, or 95% or less.
  • the conductive structure 20 can suppress charging of the image display panel 100A by contacting the side surface 10c of the optical laminate 10. It is preferable that the conductive structure 20 is connected to an earth electrode or the like.
  • the image display cell 30A includes, for example, an image forming layer 32, a first transparent substrate 31, and a second transparent substrate 33.
  • the image forming layer 32 is, for example, disposed between the first transparent substrate 31 and the second transparent substrate 33, and is in contact with each of the first transparent substrate 31 and the second transparent substrate 33.
  • the adhesive sheet 1 of the optical laminate 10 is, for example, in contact with the first transparent substrate 31 of the image display cell 30A. It is preferable that no conductive layer is disposed between the adhesive sheet 1 and the first transparent substrate 31.
  • the image forming layer 32 is, for example, a liquid crystal layer containing liquid crystal molecules that are homogeneously oriented in the absence of an electric field.
  • a liquid crystal layer containing such liquid crystal molecules is suitable for the IPS (In-Plane-Switching) method.
  • the liquid crystal layer may also be used in TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, ⁇ type, VA (Vertical Alignment) type, etc.
  • TN Transmission Nematic
  • STN Super Twisted Nematic
  • VA Very Alignment
  • an image display cell having a liquid crystal layer may be called a liquid crystal cell
  • an image display panel having a liquid crystal cell may be called a liquid crystal panel.
  • the image forming layer 32 may be an EL light-emitting layer.
  • the thickness of the image forming layer 32 is, for example, 1.5 ⁇ m to 4 ⁇ m.
  • Examples of materials for the first transparent substrate 31 and the second transparent substrate 33 include glass and polymer.
  • a transparent substrate made of a polymer may be referred to as a polymer film.
  • Examples of polymers that make up a transparent substrate include polyethylene terephthalate, polycycloolefin, and polycarbonate.
  • the thickness of a transparent substrate made of glass is, for example, 0.1 mm to 1 mm.
  • the thickness of a transparent substrate made of a polymer is, for example, 10 ⁇ m to 200 ⁇ m.
  • the image display cell 30A may further include layers other than the image forming layer 32, the first transparent substrate 31, and the second transparent substrate 33.
  • the other layers include a color filter, an easy-adhesion layer, and a hard coat layer.
  • the color filter is, for example, disposed on the viewing side of the image forming layer 32, and is preferably located between the first transparent substrate 31 and the adhesive sheet 1 of the optical laminate 10.
  • the easy-adhesion layer and the hard coat layer are, for example, disposed on the surface of the first transparent substrate 31 or the second transparent substrate 33.
  • the image display panel 100A may further include other members other than the optical laminate 10, the conductive structure 20, and the image display cell 30A.
  • the image display panel 100A may further include an additional adhesive sheet 5 and an additional polarizing film 6 as other members.
  • the adhesive sheet 5 and the polarizing film 6 are located on the opposite side of the image display cell 30A from the optical laminate 10.
  • the adhesive sheet 5 is in contact with, for example, the second transparent substrate 33 of the image display cell 30A, and the polarizing film 6 is bonded to the image display cell 30A via the adhesive sheet 5.
  • the polarizing film 6 is arranged, for example, so that its absorption axis is perpendicular to the absorption axis of the polarizing film 2.
  • the polarizing film 6 can be the same as or different from the polarizing film 2.
  • the adhesive sheet 5 is formed, for example, from an adhesive composition. Examples of this adhesive composition include those described above for the adhesive sheet 1.
  • the adhesive composition forming the adhesive sheet 5 may be the same as the adhesive composition forming the adhesive sheet 1, or may be different.
  • the thickness of the adhesive sheet 5 is not particularly limited, and is, for example, about 1 to 100 ⁇ m, preferably 2 to 50 ⁇ m, more preferably 2 to 40 ⁇ m, and even more preferably 5 to 35 ⁇ m.
  • the image display panel 100A may further include, as other components, optical films used in image display devices, such as a reflective film, an anti-transmitting film, a retardation film (a ⁇ /2 plate or a ⁇ /4 plate), a viewing angle compensation film, and a brightness enhancement film.
  • optical films used in image display devices such as a reflective film, an anti-transmitting film, a retardation film (a ⁇ /2 plate or a ⁇ /4 plate), a viewing angle compensation film, and a brightness enhancement film.
  • the image display panel 100A may include one or more of these optical films.
  • the image display panel of this embodiment may be an image display panel with a built-in touch sensing function. Examples of image display panels with a built-in touch sensing function are shown in Figures 3B to 3F.
  • the image display panels 100B to 100F of Figures 3B to 3F include image display cells 30B to 30F that include a touch sensing electrode portion. In these image display cells, the touch sensing electrode portion is disposed between the first transparent substrate 31 and the second transparent substrate 33.
  • the touch sensing electrode portion has the functions of a touch sensor and touch drive.
  • the image display panels 100B to 100F are so-called in-cell type image display panels, and the image display cells 30B to 30F are so-called in-cell type image display cells.
  • the touch sensing electrode portion may be disposed on the viewing side of the first transparent substrate 31.
  • the image display panel of this embodiment may be a so-called on-cell type image display panel, and the image display cells may be so-called on-cell type image display cells.
  • the touch sensing electrode unit 35 has, for example, a touch sensor electrode 36 and a touch drive electrode 37.
  • the touch sensor electrode 36 means a (receiving) electrode for touch detection.
  • the touch sensor electrode 36 and the touch drive electrode 37 can be formed independently in various patterns. For example, when the image display cell 30B is flat, the touch sensor electrode 36 and the touch drive electrode 37 can be provided independently in the X-axis direction and the Y-axis direction, respectively, and formed in a pattern in which they intersect at right angles.
  • the touch sensor electrode 36 is disposed on the viewing side of the touch drive electrode 37.
  • the touch drive electrode 37 may be disposed on the viewing side of the touch sensor electrode 36.
  • the touch sensing electrode portion 35 the touch sensor electrode 36 and the touch drive electrode 37 may be integrated.
  • the image display cells 30D and 30E shown in Figures 3D and 3E have an electrode 38 in which the touch sensor electrode and the touch drive electrode are integrated.
  • the touch sensing electrode unit 35 or electrode 38 is disposed between the image forming layer 32 and the first transparent substrate 31 (on the viewing side of the image forming layer 32).
  • the touch sensing electrode unit 35 or electrode 38 may be disposed between the image forming layer 32 and the second transparent substrate 33 (on the lighting system side of the image forming layer 32).
  • the touch sensor electrode 36 and the touch drive electrode 37 do not need to be in contact with each other.
  • the touch sensor electrode 36 is disposed between the image forming layer 32 and the first transparent substrate 31, and the touch drive electrode 37 is disposed between the image forming layer 32 and the second transparent substrate 33.
  • the drive electrode in the touch sensing electrode section can also serve as a common electrode that controls the image forming layer 32.
  • the touch sensor electrode 36 (capacitive sensor), the touch drive electrode 37, or the electrode 38 formed by integrating these electrodes, which constitute the touch sensing electrode unit 35, function as a transparent conductive layer.
  • the material of this transparent conductive layer is not particularly limited, and examples thereof include metals such as gold, silver, copper, platinum, palladium, aluminum, nickel, chromium, titanium, iron, cobalt, tin, magnesium, and tungsten, and alloys thereof.
  • the material of the transparent conductive layer may be an oxide of a metal such as indium, tin, zinc, gallium, antimony, zirconium, or cadmium. Specific examples of this oxide include indium oxide, tin oxide, titanium oxide, cadmium oxide, and mixtures thereof.
  • the material of the transparent conductive layer may be a metal compound such as copper iodide.
  • the material of the transparent conductive layer is preferably indium oxide (ITO) containing tin oxide, tin oxide containing antimony, and the like, and ITO is particularly preferred.
  • ITO indium oxide
  • the indium oxide content in the transparent conductive layer is 80 to 99% by weight and the tin oxide content is 1 to 20% by weight.
  • the electrodes constituting the touch sensing electrode section 35 can be formed as a transparent electrode pattern by a conventional method on the inside (image forming layer 32 side) of the first transparent substrate 31 and/or the second transparent substrate 33.
  • This transparent electrode pattern is electrically connected, for example, to a wiring line (not shown) formed at the end of the transparent substrate.
  • the wiring line is connected, for example, to a controller IC (not shown).
  • the transparent electrode pattern can be in any shape depending on the application, such as a comb shape, a stripe shape, or a diamond shape.
  • the thickness of the transparent electrode pattern is, for example, 10 nm to 100 nm.
  • the width of the transparent electrode pattern is, for example, 0.1 mm to 5 mm.
  • the image display device of this embodiment includes, for example, the image display panel and the illumination system described above.
  • the image display panel is disposed, for example, closer to the viewing side than the illumination system.
  • the illumination system includes, for example, a backlight or a reflector, and irradiates light onto the image display panel.
  • the image display device may be an organic EL display or a liquid crystal display. However, the image display device is not limited to this example.
  • the image display device may be an electroluminescence (EL) display, a plasma display (PD), a field emission display (FED: Field Emission Display), etc.
  • EL electroluminescence
  • PD plasma display
  • FED Field Emission Display
  • the image display device may be used for home appliance applications, in-vehicle applications, public information display (PID) applications, etc., and is preferably an in-vehicle display.
  • the weight average molecular weight (Mw) of the (meth)acrylic polymer was measured by gel permeation chromatography (GPC).
  • the Mw/Mn of the (meth)acrylic polymer was also measured in the same manner.
  • cyclopentanone and propylene glycol monomethyl ether were added to the solution in a ratio of 45:55 so that the solid content concentration in the solution was 36%, to prepare a hard coat layer forming material.
  • the prepared hard coat layer forming material was applied onto TJ40UL (manufactured by Fujifilm Corporation, raw material: triacetyl cellulose polymer, thickness: 40 ⁇ m) so that the thickness of the hard coat layer after curing was 7 ⁇ m to form a coating film.
  • the coating film was dried at 90° C.
  • t-butylperoxyisopropyl carbonate (Kayacarvon BIC-7, manufactured by Kayaku Akzo Co., Ltd.) was added as a polymerization initiator.
  • a solution consisting of 10.0 g of t-butylperoxyisopropyl carbonate and 230 g of MIBK was added dropwise over 4 hours, while solution polymerization was carried out under reflux at about 105 to 120° C., and the mixture was further aged over 4 hours.
  • this lactone ring-containing polymer had a weight average molecular weight of 133,000, a melt flow rate of 6.5 g/10 min, and a glass transition temperature of 131°C.
  • the pellets obtained were mixed and extruded in a mass ratio of 90/10 with acrylonitrile-styrene (AS) resin (Toyo ASAS20, manufactured by Toyo Styrene Co., Ltd.) using a single-screw extruder (screw diameter 30 mm) to obtain transparent pellets.
  • AS acrylonitrile-styrene
  • the glass transition temperature of the pellets obtained was 127°C.
  • the pellets were melt-extruded from a 400 mm wide coat hanger type T-die using a 50 mm ⁇ single screw extruder to produce a film with a thickness of 120 ⁇ m.
  • the film produced was stretched 2.0 times vertically and 2.0 times horizontally at a temperature of 150°C using a biaxial stretching device to obtain a stretched film with a thickness of 30 ⁇ m (30 ⁇ m acrylic film).
  • the optical properties of this stretched film were measured to find that the total light transmittance was 93%, the in-plane retardation ⁇ nd was 0.8 nm, and the thickness direction retardation Rth was 1.5 nm.
  • a saponified HC-attached 40 ⁇ m TAC film (triacetyl cellulose film side) was bonded to one side of the polarizer with a polyvinyl alcohol-based adhesive. Furthermore, a 30 ⁇ m acrylic film was bonded to the other side of the polarizer with a polyvinyl alcohol-based adhesive. This resulted in a polarizing film F1.
  • a polyvinyl alcohol film having a thickness of 80 ⁇ m was stretched to 3 times while being dyed for 1 minute in an iodine solution having a concentration of 0.3% at a temperature of 30° C. between rolls having different speed ratios.
  • the film was stretched to a total stretching ratio of 6 times while being immersed for 0.5 minutes in an aqueous solution having a temperature of 60° C. and containing boric acid at a concentration of 4% and potassium iodide at a concentration of 10%.
  • the film was immersed for 10 seconds in an aqueous solution having a temperature of 30° C. and containing potassium iodide at a concentration of 1.5% to wash, and then dried at 50° C.
  • a polarizer having a thickness of 28 ⁇ m A transparent protective film having a thickness of 30 ⁇ m and made of a modified acrylic polymer having a lactone ring structure was bonded to one surface of the polarizer with a polyvinyl alcohol adhesive. Furthermore, a transparent protective film having a thickness of 47 ⁇ m, which was made of a triacetyl cellulose film (manufactured by Konica Minolta, product name "KC4UY”) with a hard coat layer (HC) formed thereon, was bonded to the other surface of the polarizer with a polyvinyl alcohol adhesive. The film was dried by heating in an oven set at 70° C. for 5 minutes to prepare a polarizing film F2.
  • IPA copolymerized PET amorphous isophthalic acid copolymerized polyethylene terephthalate film (thickness: 100 ⁇ m) substrate having a water absorption rate of 0.75% and a Tg of 75° C.
  • the obtained laminate was uniaxially stretched at the free end by 2.0 times in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds in an oven at 120°C (air-assisted stretching treatment).
  • the laminate was immersed in an insolubilization bath (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) with a liquid temperature of 30°C for 30 seconds (insolubilization treatment).
  • the laminate was immersed in a dyeing bath (an iodine aqueous solution obtained by blending 0.2 parts by weight of iodine and 1.0 part by weight of potassium iodide with 100 parts by weight of water) with a liquid temperature of 30°C for 60 seconds (dyeing treatment).
  • a dyeing bath an iodine aqueous solution obtained by blending 0.2 parts by weight of iodine and 1.0 part by weight of potassium iodide with 100 parts by weight of water
  • a crosslinking bath a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with 100 parts by weight of water
  • the laminate was immersed in an aqueous solution of boric acid (aqueous solution obtained by blending 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 70°C, and uniaxially stretched between rolls with different peripheral speeds in the longitudinal direction (longitudinal direction) to a total stretch ratio of 5.5 times (underwater stretching treatment).
  • the laminate was immersed in a cleaning bath (aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 30°C (cleaning treatment).
  • a cleaning bath aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water
  • An ultraviolet-curing adhesive was prepared by mixing 45 parts by weight of acryloylmorpholine, 45 parts of 1,9-nonanediol diacrylate, 10 parts of an acrylic oligomer obtained by polymerizing a (meth)acrylic monomer (ARUFONUP1190, manufactured by Toagosei Co., Ltd.), 3 parts of a photopolymerization initiator (IRGACURE907, manufactured by BASF Corporation), and 1.5 parts of a polymerization initiator (KAYACURE DETX-S, manufactured by Nippon Kayaku Co., Ltd.).
  • the above ultraviolet-curable adhesive was applied to the surface of the polarizer of the optical film laminate so that the thickness of the adhesive layer after curing was 1 ⁇ m, and a 25 ⁇ m TAC film with HC (triacetyl cellulose film side) was bonded.
  • the 25 ⁇ m TAC film with HC was produced by the same method as the above 40 ⁇ m TAC film with HC.
  • ultraviolet rays were irradiated as active energy rays to cure the adhesive.
  • a gallium-encapsulated metal halide lamp, an irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., a bulb: V bulb, a peak illuminance: 1600 mW/cm 2 , and an integrated dose of 1000/mJ/cm 2 (wavelength 380 to 440 nm) were used, and the illuminance of the ultraviolet rays was measured using a Sola-Check system manufactured by Solatell.
  • the amorphous PET substrate was peeled off, and a polarizing film F3 using a thin polarizer was produced.
  • the optical properties of the obtained polarizing film F3 were a single transmittance of 42.8% and a polarization degree of 99.99%.
  • Example 1 [Preparation of (meth)acrylic polymer A1] First, a monomer mixture containing 60 parts by weight of methoxyethyl acrylate, 39 parts by weight of butyl acrylate, and 1 part by weight of 4-hydroxybutyl acrylate was charged into a four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler. Furthermore, 0.1 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) was charged as a polymerization initiator together with 100 parts by weight of ethyl acetate per 100 parts by weight of the monomer mixture. While gently stirring the mixture, nitrogen gas was introduced into the flask to replace the atmosphere with nitrogen.
  • AIBN 2,2'-azobisisobutyronitrile
  • a pressure-sensitive adhesive composition was prepared by blending 5 parts by weight of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (ELEXEL AS-110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 0.6 parts by weight of an isocyanate crosslinking agent (Coronate L, manufactured by Tosoh Corporation, trimethylolpropane tolylene diisocyanate), and 0.1 parts by weight of benzoyl peroxide (Niper BMT, manufactured by NOF Corporation) with respect to 100 parts by weight of the solid content of the (meth)acrylic polymer A1 solution.
  • ELEXEL AS-110 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
  • an isocyanate crosslinking agent Coronate L, manufactured by Tosoh Corporation, trimethylolpropane tolylene diisocyanate
  • benzoyl peroxide Niper BMT, manufactured by NOF Corporation
  • the above pressure-sensitive adhesive composition was applied to one side of a polyethylene terephthalate film (release liner: MRF38, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) treated with a silicone-based release agent, so that the thickness of the adhesive sheet after drying was 20 ⁇ m.
  • the resulting coating film was dried at 155° C. for 1 minute to form an adhesive sheet on the surface of the release liner.
  • the adhesive sheet formed on the release liner was transferred to the acrylic film side of the above-mentioned polarizing film F1 to produce an optical laminate (polarizing film with adhesive sheet).
  • the release liner was peeled off from the optical laminate and attached to the surface of the viewing side of the in-cell type liquid crystal cell.
  • a conductive paste (ELEPASTE NP-1, manufactured by Taiyo Ink Co., Ltd.) was applied to the part (part S1 in FIG. 2) of the side of the optical laminate extending in the absorption axis direction of the polarizing film, and cured to form a conductive structure.
  • the conductive paste contained silver particles and polyester resin, and the content of the conductive component (silver particles) was 57% by weight.
  • the conductive structure was in contact with each side of the adhesive sheet and the polarizing film.
  • the conductive structure was connected to an external earth electrode.
  • the wiring around the transparent electrode pattern inside the in-cell type liquid crystal cell was connected to the controller IC. In this way, an image display panel (liquid crystal panel) of Example 1 with a built-in touch sensing function was produced.
  • Example 2 Examples 2 to 5, Comparative Examples 1 and 2
  • image display panels (liquid crystal panels) of Examples 2 to 5 and Comparative Examples 1 and 2 were produced by the same method as Example 1, except that the composition of the adhesive composition, the type of polarizing film, and the type of conductive paste were changed.
  • the conductive paste used in Example 2 (SX-ECA48, manufactured by Cemedine) contained silver particles and polyester resin, and the content of the conductive component was 70 to 80% by weight.
  • the conductive paste used in Comparative Example 2 (TB3331D, manufactured by ThreeBond) contained nickel particles and epoxy resin, and the content of the conductive component was 46% by weight.
  • Figures 4 to 7 are SEM images showing the surfaces of the image display panels of Examples 1 and 2 and Comparative Examples 1 and 2 after heat treatment. These images show that in Examples 1 and 2, almost no breaks occur between the conductive structure 20 and the optical laminate 10, whereas in Comparative Examples 1 and 2, breaks do occur.
  • the conductive paste is applied to the portion of the side of the optical laminate where the dimensional change determined by Test 1 is 80 ⁇ m or less to form a conductive structure
  • the breaking elongation of the conductive paste determined by Test 2 is 5% or more
  • breakage between the conductive structure and the optical laminate in a high temperature and high humidity environment was sufficiently suppressed compared to the comparative example.
  • the antistatic performance is less likely to decrease even when exposed to a high temperature and high humidity environment.
  • the image display panel set of the present invention is suitable for producing an image display panel whose antistatic performance is unlikely to deteriorate even when exposed to a high-temperature and high-humidity environment.

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  • Liquid Crystal (AREA)
  • Devices For Indicating Variable Information By Combining Individual Elements (AREA)
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  • Adhesive Tapes (AREA)
  • Adhesives Or Adhesive Processes (AREA)

Abstract

The present invention provides a set for image display panels, the set being suitable for the production of an image display panel which is not susceptible to a decrease in the antistatic performance even after being exposed to a high temperature high humidity environment, and in which a conduction structure is formed on a lateral surface of an optical multilayer body. A set for image display panels according to the present invention is provided with: an optical multilayer body 10 which comprises a polarizing film 2 and an adhesive sheet 1; and a conductive paste. The conductive paste forms a conduction structure 20 by being applied to a portion of a lateral surface 10c of the optical multilayer body 10, the portion having a dimensional change amount of 80 µm or less as determined by test 1. The conductive paste has an elongation at break of 5% or more as determined by test 2.

Description

画像表示パネル用セット、及び画像表示パネルImage display panel set and image display panel
　本発明は、画像表示パネル用セット、及び画像表示パネルに関する。 The present invention relates to a set for an image display panel and an image display panel.
　液晶表示装置及びエレクトロルミネセンス（ＥＬ）表示装置に代表される各種の画像表示装置は、例えば、液晶セル、ＥＬ発光素子等の画像表示セルと、偏光フィルム及び粘着シートを含む光学積層体とが積層された画像表示パネルを有している。粘着シートは、主に、光学積層体に含まれるフィルム間の接合や、画像表示セルと光学積層体との接合に使用される。 Various image display devices, such as liquid crystal display devices and electroluminescence (EL) display devices, have an image display panel in which an image display cell, such as a liquid crystal cell or an EL light-emitting element, is laminated with an optical laminate including a polarizing film and an adhesive sheet. The adhesive sheet is mainly used to bond between the films included in the optical laminate, and to bond the image display cell to the optical laminate.
　画像表示装置では、その製造時、例えば粘着シートを介して光学積層体を画像表示セルに貼り合わせるとき、又は、使用時、例えば使用者が画像表示装置に触れるとき、に静電気が生じる。この静電気によって、画像表示装置が帯電すると、表示不良などの問題が生じうる。特許文献１は、画像表示装置の帯電を防止するために、粘着シートに帯電防止剤を添加することを開示している。 In image display devices, static electricity is generated during their manufacture, for example when the optical laminate is attached to the image display cell via an adhesive sheet, or during use, for example when a user touches the image display device. If the image display device becomes charged with this static electricity, problems such as display defects can occur. Patent Document 1 discloses the addition of an antistatic agent to the adhesive sheet in order to prevent the image display device from becoming charged.
特表２０１１－５２８４４８公報Patent Publication No. 2011-528448
　静電気が特に生じやすい環境、例えば車両の内部のように他の電子機器が周囲に存在する環境、で画像表示装置を用いる場合、画像表示装置について、帯電を十分に抑制する必要がある。画像表示装置の帯電を十分に抑制する観点からは、光学積層体の側面に導通構造を配置した画像表示パネルを用いる対応が考えられる。一例として、導通構造は、導電性ペーストを光学積層体の側面に塗布し、必要に応じて硬化させることによって形成することができる。 When an image display device is used in an environment where static electricity is particularly likely to occur, such as the inside of a vehicle where other electronic devices are present in the vicinity, it is necessary to sufficiently suppress charging of the image display device. From the perspective of sufficiently suppressing charging of the image display device, it is possible to use an image display panel in which a conductive structure is arranged on the side of the optical laminate. As one example, the conductive structure can be formed by applying a conductive paste to the side of the optical laminate and curing it as necessary.
　しかし、本発明者らの検討によると、導電性ペーストから形成された導通構造を備えた画像表示パネルは、高温多湿環境を経た場合に、その帯電防止性能が著しく低下する傾向がある。 However, according to the inventors' research, image display panels equipped with a conductive structure formed from a conductive paste tend to show a significant decrease in their antistatic performance when exposed to a high-temperature, high-humidity environment.
　そこで本発明は、光学積層体の側面に導通構造を形成した画像表示パネルであって、高温多湿環境を経た場合でも帯電防止性能が低下しにくい画像表示パネルを作製することに適した画像表示パネル用セットを提供することを目的とする。 The present invention aims to provide a set for an image display panel that is suitable for producing an image display panel in which a conductive structure is formed on the side surface of an optical laminate, and in which the antistatic performance is unlikely to deteriorate even when exposed to a high-temperature, high-humidity environment.
　本発明者らは、鋭意検討の結果、従来の画像表示装置では、高温多湿環境下において、導通構造と光学積層体との間で破断が生じ、これにより、帯電防止性能が著しく低下することを新たに突き止め、本発明を完成するに至った。 After extensive research, the inventors discovered that in conventional image display devices, breaks occur between the conductive structure and the optical laminate in high-temperature, high-humidity environments, which causes a significant decrease in antistatic performance, and this led to the completion of the present invention.
　本発明は、
　偏光フィルム及び粘着シートを有する光学積層体と、導電性ペーストと、を備える画像表示パネル用セットであって、
　前記導電性ペーストは、前記光学積層体の側面のうち、下記試験１により求めた寸法変化量が８０μｍ以下となる部分に塗布されて導通構造を形成し、
　前記導電性ペーストについて、下記試験２により求めた破断伸度が５％以上である、画像表示パネル用セットを提供する。
　試験１：前記粘着シートを介して、前記光学積層体を無アルカリガラスに貼り付けて、温度８５℃、湿度８５％ＲＨの条件で２４０時間加熱処理を行う。前記加熱処理の前後での前記光学積層体の面方向における寸法変化量を特定する。
　試験２：前記導電性ペーストから、厚さ２ｍｍの平膜を作製する。前記平膜を打ち抜き、ダンベル状１号形の試験片を作製する。前記試験片を引張試験機にセットし、初期のチャック間距離１０ｍｍ、引張速度３００ｍｍ／ｍｉｎの条件で引張試験を行い、前記試験片が破断したときの伸び（破断伸度）を特定する。 The present invention relates to
A set for an image display panel comprising an optical laminate having a polarizing film and an adhesive sheet, and a conductive paste,
The conductive paste is applied to a portion of the side surface of the optical laminate where the dimensional change amount determined by the following Test 1 is 80 μm or less to form a conductive structure,
The conductive paste has a breaking elongation of 5% or more as determined by the following Test 2.
Test 1: The optical laminate is attached to non-alkali glass via the pressure-sensitive adhesive sheet, and is subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH. The amount of dimensional change in the planar direction of the optical laminate before and after the heat treatment is determined.
Test 2: A flat film having a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
　さらに本発明は、
　画像表示セルと、
　偏光フィルム及び粘着シートを備える光学積層体と、
　導電性ペーストから形成され、前記光学積層体の側面のうち、下記試験１により求めた寸法変化量が８０μｍ以下となる部分に接触している導通構造と、
を備え、
　前記導電性ペーストについて、下記試験２により求めた破断伸度が５％以上である、画像表示パネルを提供する。
　試験１：前記粘着シートを介して、前記光学積層体を無アルカリガラスに貼り付けて、温度８５℃、湿度８５％ＲＨの条件で２４０時間加熱処理を行う。前記加熱処理の前後での前記光学積層体の面方向における寸法変化量を特定する。
　試験２：前記導電性ペーストから、厚さ２ｍｍの平膜を作製する。前記平膜を打ち抜き、ダンベル状１号形の試験片を作製する。前記試験片を引張試験機にセットし、初期のチャック間距離１０ｍｍ、引張速度３００ｍｍ／ｍｉｎの条件で引張試験を行い、前記試験片が破断したときの伸び（破断伸度）を特定する。 Further, the present invention relates to
an image display cell;
An optical laminate including a polarizing film and a pressure-sensitive adhesive sheet;
A conductive structure formed from a conductive paste and in contact with a portion of the side surface of the optical laminate where the dimensional change amount determined by the following Test 1 is 80 μm or less;
Equipped with
The conductive paste has a breaking elongation of 5% or more as determined by the following Test 2, and the image display panel is provided.
Test 1: The optical laminate is attached to non-alkali glass via the pressure-sensitive adhesive sheet, and is subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH. The amount of dimensional change in the planar direction of the optical laminate before and after the heat treatment is determined.
Test 2: A flat film having a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
　本発明によれば、光学積層体の側面に導通構造を形成した画像表示パネルであって、高温多湿環境を経た場合でも帯電防止性能が低下しにくい画像表示パネルを作製することに適した画像表示パネル用セットを提供できる。 The present invention provides a set for an image display panel that is suitable for producing an image display panel in which a conductive structure is formed on the side surface of an optical laminate, and in which antistatic performance is unlikely to deteriorate even when exposed to a high-temperature, high-humidity environment.
本発明の光学積層体の一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view illustrating an example of an optical laminate of the present invention. 試験１の加熱処理を行ったときの光学積層体の寸法変化量を説明するための図である。FIG. 1 is a diagram for explaining the amount of dimensional change of the optical laminate when the heat treatment in Test 1 is performed. 本発明の画像表示パネルの一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention. 本発明の画像表示パネルの一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention. 本発明の画像表示パネルの一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention. 本発明の画像表示パネルの一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention. 本発明の画像表示パネルの一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention. 本発明の画像表示パネルの一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view that illustrates an example of an image display panel of the present invention. 加熱処理を行った後の実施例１の画像表示パネルの表面を示す走査型電子顕微鏡（ＳＥＭ）画像である。1 is a scanning electron microscope (SEM) image showing the surface of the image display panel of Example 1 after the heat treatment. 加熱処理を行った後の実施例２の画像表示パネルの表面を示すＳＥＭ画像である。11 is a SEM image showing the surface of the image display panel of Example 2 after the heat treatment. 加熱処理を行った後の比較例１の画像表示パネルの表面を示すＳＥＭ画像である。11 is a SEM image showing the surface of the image display panel of Comparative Example 1 after the heat treatment. 加熱処理を行った後の比較例２の画像表示パネルの表面を示すＳＥＭ画像である。11 is a SEM image showing the surface of the image display panel of Comparative Example 2 after the heat treatment.
　本発明の第１態様にかかる画像表示パネル用セットは、
　偏光フィルム及び粘着シートを有する光学積層体と、導電性ペーストと、を備える画像表示パネル用セットであって、
　前記導電性ペーストは、前記光学積層体の側面のうち、下記試験１により求めた寸法変化量が８０μｍ以下となる部分に塗布されて導通構造を形成し、
　前記導電性ペーストについて、下記試験２により求めた破断伸度が５％以上である。
　試験１：前記粘着シートを介して、前記光学積層体を無アルカリガラスに貼り付けて、温度８５℃、湿度８５％ＲＨの条件で２４０時間加熱処理を行う。前記加熱処理の前後での前記光学積層体の面方向における寸法変化量を特定する。
　試験２：前記導電性ペーストから、厚さ２ｍｍの平膜を作製する。前記平膜を打ち抜き、ダンベル状１号形の試験片を作製する。前記試験片を引張試験機にセットし、初期のチャック間距離１０ｍｍ、引張速度３００ｍｍ／ｍｉｎの条件で引張試験を行い、前記試験片が破断したときの伸び（破断伸度）を特定する。 The set for an image display panel according to the first aspect of the present invention comprises:
A set for an image display panel comprising an optical laminate having a polarizing film and an adhesive sheet, and a conductive paste,
The conductive paste is applied to a portion of the side surface of the optical laminate where the dimensional change amount determined by the following Test 1 is 80 μm or less to form a conductive structure,
The conductive paste has a breaking elongation of 5% or more as determined by the following Test 2.
Test 1: The optical laminate is attached to non-alkali glass via the pressure-sensitive adhesive sheet, and is subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH. The amount of dimensional change in the planar direction of the optical laminate before and after the heat treatment is determined.
Test 2: A flat film having a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
　本発明の第２態様において、例えば、第１態様にかかるセットでは、前記破断伸度が２５％以上である。 In the second aspect of the present invention, for example, in the set according to the first aspect, the breaking elongation is 25% or more.
　本発明の第３態様において、例えば、第１又は第２態様にかかるセットでは、前記導電性ペーストは、金属及びバインダーを含む。 In a third aspect of the present invention, for example in the set according to the first or second aspect, the conductive paste contains a metal and a binder.
　本発明の第４態様において、例えば、第３態様にかかるセットでは、前記バインダーは、ポリエステル樹脂及びシリコーン樹脂からなる群より選ばれる少なくとも１つを含む。 In the fourth aspect of the present invention, for example, in the set according to the third aspect, the binder includes at least one selected from the group consisting of polyester resin and silicone resin.
　本発明の第５態様において、例えば、第３又は第４態様にかかるセットでは、前記バインダーは、エポキシ樹脂を実質的に含まない。 In a fifth aspect of the present invention, for example in the set according to the third or fourth aspect, the binder is substantially free of epoxy resin.
　本発明の第６態様において、例えば、第３～第５態様のいずれか１つにかかるセットでは、前記金属は、銀を含む。 In a sixth aspect of the present invention, for example, in a set according to any one of the third to fifth aspects, the metal includes silver.
　本発明の第７態様において、例えば、第１～第６態様のいずれか１つにかかるセットでは、前記偏光フィルムは、２つの保護フィルムと、２つの前記保護フィルムの間に配置された偏光子とを有する。 In the seventh aspect of the present invention, for example in a set according to any one of the first to sixth aspects, the polarizing film has two protective films and a polarizer disposed between the two protective films.
　本発明の第８態様において、例えば、第７態様にかかるセットでは、前記偏光子の厚さが６μｍ以上である。 In the eighth aspect of the present invention, for example, in the set according to the seventh aspect, the thickness of the polarizer is 6 μm or more.
　本発明の第９態様において、例えば、第１～第８態様のいずれか１つにかかるセットでは、前記粘着シートは、(メタ)アクリル系ポリマー（Ａ）を含む粘着剤組成物から形成される。 In a ninth aspect of the present invention, for example, in a set according to any one of the first to eighth aspects, the pressure-sensitive adhesive sheet is formed from a pressure-sensitive adhesive composition containing a (meth)acrylic polymer (A).
　本発明の第１０態様において、例えば、第９態様にかかるセットでは、前記(メタ)アクリル系ポリマー（Ａ）は、エーテル基含有単量体に由来する構成単位を有する。 In the tenth aspect of the present invention, for example, in the set according to the ninth aspect, the (meth)acrylic polymer (A) has a constituent unit derived from an ether group-containing monomer.
　本発明の第１１態様において、例えば、第９又は第１０態様にかかるセットでは、前記粘着剤組成物は、帯電防止剤をさらに含む。 In an eleventh aspect of the present invention, for example, in a set according to the ninth or tenth aspect, the adhesive composition further comprises an antistatic agent.
　本発明の第１２態様において、例えば、第１～第１１態様のいずれか１つにかかるセットでは、２５℃における前記粘着シートの貯蔵弾性率Ｇ’が９．０×１０4Ｐａ以上である。 In a twelfth aspect of the present invention, for example, in the set according to any one of the first to eleventh aspects, the pressure-sensitive adhesive sheet has a storage modulus G' at 25° C. of 9.0×10 4 Pa or more.
　本発明の第１３態様において、例えば、第１～第１２態様のいずれか１つにかかるセットでは、前記粘着シートは、前記偏光フィルムと直接接している。 In the thirteenth aspect of the present invention, for example, in a set according to any one of the first to twelfth aspects, the adhesive sheet is in direct contact with the polarizing film.
　本発明の第１４態様にかかる画像表示パネルは、
　画像表示セルと、
　偏光フィルム及び粘着シートを備える光学積層体と、
　導電性ペーストから形成され、前記光学積層体の側面のうち、下記試験１により求めた寸法変化量が８０μｍ以下となる部分に接触している導通構造と、
を備え、
　前記導電性ペーストについて、下記試験２により求めた破断伸度が５％以上である。
　試験１：前記粘着シートを介して、前記光学積層体を無アルカリガラスに貼り付けて、温度８５℃、湿度８５％ＲＨの条件で２４０時間加熱処理を行う。前記加熱処理の前後での前記光学積層体の面方向における寸法変化量を特定する。
　試験２：前記導電性ペーストから、厚さ２ｍｍの平膜を作製する。前記平膜を打ち抜き、ダンベル状１号形の試験片を作製する。前記試験片を引張試験機にセットし、初期のチャック間距離１０ｍｍ、引張速度３００ｍｍ／ｍｉｎの条件で引張試験を行い、前記試験片が破断したときの伸び（破断伸度）を特定する。 An image display panel according to a fourteenth aspect of the present invention comprises:
an image display cell;
An optical laminate including a polarizing film and a pressure-sensitive adhesive sheet;
A conductive structure formed from a conductive paste and in contact with a portion of the side surface of the optical laminate where the dimensional change amount determined by the following Test 1 is 80 μm or less;
Equipped with
The conductive paste has a breaking elongation of 5% or more as determined by the following Test 2.
Test 1: The optical laminate is attached to non-alkali glass via the pressure-sensitive adhesive sheet, and is subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH. The amount of dimensional change in the planar direction of the optical laminate before and after the heat treatment is determined.
Test 2: A flat film having a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
　本発明の第１５態様において、例えば、第１４態様にかかる画像表示パネルは、タッチセンシング機能を内蔵する。 In a fifteenth aspect of the present invention, for example, the image display panel according to the fourteenth aspect has a built-in touch sensing function.
　以下に本発明を詳細に説明するが、本発明は以下の実施形態に限定されるものではなく、本発明の要旨を逸脱しない範囲において、任意に変形して実施することができる。 The present invention is described in detail below, but is not limited to the following embodiments, and can be modified as desired without departing from the spirit of the invention.
＜画像表示パネル用セットの実施形態＞
　本実施形態の画像表示パネル用セットは、光学積層体と導電性ペーストとを備える。本実施形態の画像表示パネル用セットが備えうる光学積層体の一例を図１に示す。図１の光学積層体１０は、偏光フィルム２及び粘着シート１を有しており、例えば、粘着シート１及び偏光フィルム２のみから構成されている。光学積層体１０において、粘着シート１は、偏光フィルム２と直接接していることが好ましい。ただし、光学積層体１０は、粘着シート１及び偏光フィルム２以外の他の部材（例えば、アンカー層や導電層）を備えていてもよく、当該他の部材が粘着シート１及び偏光フィルム２の間に配置されていてもよい。光学積層体１０は、粘着シート１を介して、対象物（例えば、画像表示セル）と貼り合わせることが可能であり、粘着シート付き偏光フィルムとして使用できる。 <Embodiment of Image Display Panel Set>
The image display panel set of this embodiment includes an optical laminate and a conductive paste. FIG. 1 shows an example of an optical laminate that may be included in the image display panel set of this embodiment. The optical laminate 10 of FIG. 1 has a polarizing film 2 and an adhesive sheet 1, and is composed of, for example, only the adhesive sheet 1 and the polarizing film 2. In the optical laminate 10, it is preferable that the adhesive sheet 1 is in direct contact with the polarizing film 2. However, the optical laminate 10 may include other members (e.g., an anchor layer or a conductive layer) other than the adhesive sheet 1 and the polarizing film 2, and the other members may be disposed between the adhesive sheet 1 and the polarizing film 2. The optical laminate 10 can be attached to an object (e.g., an image display cell) via the adhesive sheet 1, and can be used as a polarizing film with an adhesive sheet.
　本実施形態において、光学積層体１０は、例えば、シート状であり、互いに対向する一対の主面１０ａ及び１０ｂと、側面１０ｃとを有する。導電性ペーストは、光学積層体１０の側面１０ｃのうち、下記試験１により求めた寸法変化量が８０μｍ以下となる部分に塗布されて導通構造を形成する。なお、導通構造を形成するときには、必要に応じて、上記の部分に塗布された導電性ペーストを硬化させてもよい。
　試験１：粘着シート１を介して、光学積層体１０を無アルカリガラスに貼り付けて、温度８５℃、湿度８５％ＲＨの条件で２４０時間加熱処理を行う。加熱処理の前後での光学積層体１０の面方向の寸法変化量を特定する。 In this embodiment, the optical laminate 10 is, for example, sheet-like and has a pair of opposing main surfaces 10a and 10b and a side surface 10c. The conductive paste is applied to a portion of the side surface 10c of the optical laminate 10 where the dimensional change amount determined by the following test 1 is 80 μm or less to form a conductive structure. When forming the conductive structure, the conductive paste applied to the above portion may be cured as necessary.
Test 1: The optical laminate 10 is attached to non-alkali glass via the adhesive sheet 1, and heat-treated for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH. The amount of dimensional change in the planar direction of the optical laminate 10 before and after the heat treatment is determined.
　試験１は、詳細には、次の方法によって行う。まず、光学積層体１０を準備する。光学積層体１０は、例えば平面視で矩形であり、縦５０～１５００ｍｍ、横５０～１５００ｍｍのサイズを有する。図２は、光学積層体１０の端部付近の平面概念図の一例である。図２では、加熱処理を行う前の光学積層体１０の外縁が実線で示されている。図２に示すように、光学積層体１０は、例えば、平面視で、角部が面取りされた矩形の形状を有している。光学積層体１０の側面１０ｃは、例えば、偏光フィルム２の吸収軸方向に延びる部分Ｓ１、偏光フィルム２の遅相軸方向に延びる部分Ｓ２、及び、面取りされた角部を規定する部分Ｓ３を有する。なお、偏光フィルム２の吸収軸方向と遅相軸方向とは、通常、互いに直交している。 Test 1 is carried out in detail by the following method. First, the optical laminate 10 is prepared. The optical laminate 10 is, for example, rectangular in plan view, with a length of 50 to 1500 mm and a width of 50 to 1500 mm. FIG. 2 is an example of a plan view of the vicinity of the end of the optical laminate 10. In FIG. 2, the outer edge of the optical laminate 10 before the heat treatment is performed is shown by a solid line. As shown in FIG. 2, the optical laminate 10 has, for example, a rectangular shape with chamfered corners in plan view. The side surface 10c of the optical laminate 10 has, for example, a portion S1 extending in the absorption axis direction of the polarizing film 2, a portion S2 extending in the slow axis direction of the polarizing film 2, and a portion S3 that defines the chamfered corners. Note that the absorption axis direction and the slow axis direction of the polarizing film 2 are usually perpendicular to each other.
　次に、粘着シート１を介して、光学積層体１０を無アルカリガラスに貼り付ける。無アルカリガラスは、アルカリ成分（アルカリ金属酸化物）を実質的に含まないガラスであり、詳細には、ガラスにおけるアルカリ成分の重量比率が、例えば１０００ｐｐｍ以下であり、さらには５００ｐｐｍ以下である。無アルカリガラスは、例えば板状であり、０．５ｍｍ以上の厚さを有する。無アルカリガラスへの光学積層体１０の貼り付けは、例えば、光学積層体１０の表面全体を無アルカリガラスに重ね合わせ、２ｋｇのローラを１往復させて、これらを圧着させることによって行う。 Next, the optical laminate 10 is attached to the alkali-free glass via the adhesive sheet 1. The alkali-free glass is glass that does not substantially contain alkali components (alkali metal oxides), and more specifically, the weight ratio of the alkali components in the glass is, for example, 1000 ppm or less, and even 500 ppm or less. The alkali-free glass is, for example, in the form of a plate, and has a thickness of 0.5 mm or more. The optical laminate 10 is attached to the alkali-free glass, for example, by overlapping the entire surface of the optical laminate 10 on the alkali-free glass and pressing them together by moving a 2 kg roller back and forth once.
　次に、光学積層体１０を温度８５℃、湿度８５％ＲＨの環境下に２４０時間配置することによって、加熱処理を行う。このとき、光学積層体１０は、通常、面方向に収縮する。図２では、加熱処理を行った後の光学積層体１０の外縁が破線で示されている。図２において、Ｌ１が、加熱処理の前後での部分Ｓ１の面方向の寸法変化量（収縮量）に相当し、Ｌ２が、加熱処理の前後での部分Ｓ２の面方向の寸法変化量（収縮量）に相当し、Ｌ３が、加熱処理の前後での部分Ｓ３の面方向の寸法変化量（収縮量）に相当する。寸法変化量Ｌ１～Ｌ３は、顕微鏡観察により特定することができる。 Next, the optical laminate 10 is placed in an environment with a temperature of 85°C and a humidity of 85% RH for 240 hours to perform a heat treatment. At this time, the optical laminate 10 usually shrinks in the planar direction. In FIG. 2, the outer edge of the optical laminate 10 after the heat treatment is shown by a dashed line. In FIG. 2, L1 corresponds to the amount of dimensional change (amount of shrinkage) in the planar direction of portion S1 before and after the heat treatment, L2 corresponds to the amount of dimensional change (amount of shrinkage) in the planar direction of portion S2 before and after the heat treatment, and L3 corresponds to the amount of dimensional change (amount of shrinkage) in the planar direction of portion S3 before and after the heat treatment. The dimensional changes L1 to L3 can be determined by microscopic observation.
　なお、光学積層体１０の収縮は、通常、偏光フィルム２の遅相軸方向と比べて、偏光フィルム２の吸収軸方向に強く生じる傾向がある。そのため、部分Ｓ１の寸法変化量Ｌ１（μｍ）、部分Ｓ２の寸法変化量Ｌ２（μｍ）、及び、部分Ｓ３の寸法変化量Ｌ３（μｍ）は、例えば、Ｌ２＞Ｌ３＞Ｌ１の関係を満たす。 In addition, the shrinkage of the optical laminate 10 usually tends to occur more strongly in the absorption axis direction of the polarizing film 2 than in the slow axis direction of the polarizing film 2. Therefore, the dimensional change amount L1 (μm) of portion S1, the dimensional change amount L2 (μm) of portion S2, and the dimensional change amount L3 (μm) of portion S3 satisfy the relationship L2>L3>L1, for example.
　本実施形態では、部分Ｓ１の寸法変化量Ｌ１が８０μｍ以下であり、導電性ペーストが当該部分Ｓ１に塗布されて導通構造を形成することが好ましい。この場合、導電性ペーストは、部分Ｓ１の全体に塗布されてもよく、部分Ｓ１の一部に塗布されてもよい。寸法変化量Ｌ１が８０μｍ以下である場合、部分Ｓ２の寸法変化量Ｌ２及び部分Ｓ３の寸法変化量Ｌ３は、それぞれ、８０μｍより大きくてもよいが、８０μｍ以下であってもよい。寸法変化量Ｌ１～Ｌ３がいずれも８０μｍ以下である場合、部分Ｓ１～Ｓ３のうちの少なくとも１つに導電性ペーストを塗布して導通構造を形成することができる。 In this embodiment, it is preferable that the dimensional change L1 of portion S1 is 80 μm or less, and that a conductive paste is applied to portion S1 to form a conductive structure. In this case, the conductive paste may be applied to the entire portion S1, or to a part of portion S1. When the dimensional change L1 is 80 μm or less, the dimensional change L2 of portion S2 and the dimensional change L3 of portion S3 may each be greater than 80 μm, but may also be 80 μm or less. When the dimensional changes L1 to L3 are all 80 μm or less, a conductive structure can be formed by applying a conductive paste to at least one of portions S1 to S3.
　寸法変化量Ｌ１～Ｌ３（特に寸法変化量Ｌ１）は、７０μｍ以下であってもよく、６０μｍ以下、５０μｍ以下、４０μｍ以下、さらには３５μｍ以下であってもよい。寸法変化量Ｌ１～Ｌ３の下限は、特に限定されず、例えば１０μｍ以上であり、２０μｍ以上、さらには３０μｍ以上であってもよい。 The dimensional changes L1 to L3 (particularly the dimensional change L1) may be 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, or even 35 μm or less. The lower limit of the dimensional changes L1 to L3 is not particularly limited, and may be, for example, 10 μm or more, 20 μm or more, or even 30 μm or more.
　なお、寸法変化量Ｌ２（μｍ）に対する寸法変化量Ｌ１（μｍ）の比Ｌ１／Ｌ２は、特に限定されず、例えば０．８未満であり、０．７以下、さらには０．６以下であってもよい。比Ｌ１／Ｌ２が０．８未満である場合、部分Ｓ１に導電性ペーストを塗布して形成された導通構造は、部分Ｓ１との密着性を保持しやすい。比Ｌ１／Ｌ２の下限は、特に限定されず、例えば０．４である。 The ratio L1/L2 of the dimensional change amount L1 (μm) to the dimensional change amount L2 (μm) is not particularly limited and may be, for example, less than 0.8, 0.7 or less, or even 0.6 or less. When the ratio L1/L2 is less than 0.8, the conductive structure formed by applying the conductive paste to the portion S1 is likely to maintain adhesion with the portion S1. The lower limit of the ratio L1/L2 is not particularly limited and is, for example, 0.4.
　さらに、本実施形態では、導電性ペーストについて、下記試験２により求めた破断伸度が５％以上である。
　試験２：導電性ペーストから、厚さ２ｍｍの平膜を作製する。平膜を打ち抜き、ダンベル状１号形の試験片を作製する。試験片を引張試験機にセットし、初期のチャック間距離１０ｍｍ、引張速度３００ｍｍ／ｍｉｎの条件で引張試験を行い、試験片が破断したときの伸び（破断伸度）を特定する。 Furthermore, in this embodiment, the conductive paste has a breaking elongation of 5% or more as determined by the following Test 2.
Test 2: A flat film with a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
　試験２において、平膜の作製方法は特に限定されない。一例として、導電性ペーストを基材に塗布し、硬化させることによって平膜を作製することができる。導電性ペーストは、例えば、６０℃～１５０℃の環境下で、１５分～５時間加熱処理することによって硬化させることができる。 In Test 2, the method for producing the flat membrane is not particularly limited. As an example, the flat membrane can be produced by applying a conductive paste to a substrate and curing it. The conductive paste can be cured, for example, by heat treatment in an environment of 60°C to 150°C for 15 minutes to 5 hours.
　試験２において、試験片の形状（ダンベル状１号形）は、例えば、ＪＩＳ　Ｋ６２５１：２０１７に定められている。引張試験機としては、例えば、島津製作所製の引張試験機「オートグラフＡＧ－１０Ｇ」を用いることができる。引張試験は、試験片の長手方向に試験片を引っ張ることによって行う。 In Test 2, the shape of the test piece (dumbbell-shaped No. 1) is specified, for example, in JIS K6251:2017. As a tensile tester, for example, the "Autograph AG-10G" tensile tester manufactured by Shimadzu Corporation can be used. The tensile test is performed by pulling the test piece in the longitudinal direction.
　試験２により求めた破断伸度は、好ましくは１０％以上であり、１５％以上、２０％以上、２５％以上、さらには３０％以上であることが好ましい。破断伸度の上限は、特に限定されず、例えば１００％以下である。 The breaking elongation determined by Test 2 is preferably 10% or more, more preferably 15% or more, 20% or more, 25% or more, or even 30% or more. The upper limit of the breaking elongation is not particularly limited, and is, for example, 100% or less.
　上述のとおり、本実施形態のセットにおいて、導電性ペーストは、光学積層体１０の側面１０ｃのうち、試験１により求めた寸法変化量が８０μｍ以下となる部分に塗布されて導通構造を形成する。さらに、導電性ペーストについて、試験２により求めた破断伸度が５％以上である。これらの要件が満たされたセットから作製された画像表示装置や画像表示パネルでは、高温多湿環境を経た場合であっても、導通構造と光学積層体との間で破断が生じにくく、これにより、帯電防止性能が低下しにくい傾向がある。 As described above, in the set of this embodiment, the conductive paste is applied to the portion of the side surface 10c of the optical laminate 10 where the dimensional change determined by Test 1 is 80 μm or less to form a conductive structure. Furthermore, the breaking elongation determined by Test 2 for the conductive paste is 5% or more. In an image display device or image display panel manufactured from a set that satisfies these requirements, even when exposed to a high temperature and high humidity environment, breakage is unlikely to occur between the conductive structure and the optical laminate, and as a result, antistatic performance tends not to deteriorate.
［粘着シート］
　本実施形態において、粘着シート１は、粘着剤を含む層である。粘着シート１に含まれる粘着剤の例は、ゴム系粘着剤、アクリル系粘着剤、シリコーン系粘着剤、ウレタン系粘着剤、ビニルアルキルエーテル系粘着剤、ポリビニルピロリドン系粘着剤、ポリアクリルアミド系粘着剤、及びセルロース系粘着剤である。粘着剤は、光学的透明性に優れ、適切な濡れ性、凝集性、接着性等の粘着特性を有すると共に、耐候性、耐熱性等にも優れる観点から、アクリル系粘着剤であってもよい。換言すれば、粘着シート１は、アクリル系粘着シートであってもよい。以下、アクリル系粘着シートである粘着シート１について説明する。 [Adhesive sheet]
In this embodiment, the adhesive sheet 1 is a layer containing an adhesive. Examples of the adhesive contained in the adhesive sheet 1 are rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, polyvinylpyrrolidone-based adhesives, polyacrylamide-based adhesives, and cellulose-based adhesives. The adhesive may be an acrylic adhesive, which has excellent optical transparency, appropriate adhesive properties such as wettability, cohesiveness, and adhesiveness, and is also excellent in weather resistance, heat resistance, and the like. In other words, the adhesive sheet 1 may be an acrylic adhesive sheet. The adhesive sheet 1, which is an acrylic adhesive sheet, will be described below.
　本実施形態において、粘着シート１は、粘着剤組成物から形成されている。粘着剤組成物は、例えば、(メタ)アクリル系ポリマー（Ａ）を含み、帯電防止剤をさらに含んでいてもよい。粘着剤組成物における(メタ)アクリル系ポリマー（Ａ）の含有率は、５０重量％以上、６０重量％以上、７０重量％以上、さらには８０重量％以上であってもよい。本明細書において（メタ）アクリルとは、アクリル及びメタクリルを意味する。（メタ）アクリレートとは、アクリレート及びメタクリレートを意味する。なお、粘着剤組成物は、（メタ）アクリル系単量体を含む単量体群及び／又は当該単量体群の部分重合物を含む光硬化性組成物であってもよい。（メタ）アクリル系単量体としては、(メタ)アクリル系ポリマー（Ａ）について後述するものが挙げられる。 In this embodiment, the adhesive sheet 1 is formed from an adhesive composition. The adhesive composition contains, for example, a (meth)acrylic polymer (A) and may further contain an antistatic agent. The content of the (meth)acrylic polymer (A) in the adhesive composition may be 50% by weight or more, 60% by weight or more, 70% by weight or more, or even 80% by weight or more. In this specification, (meth)acrylic means acrylic and methacrylic. (Meth)acrylate means acrylate and methacrylate. The adhesive composition may be a photocurable composition containing a monomer group containing a (meth)acrylic monomer and/or a partial polymer of the monomer group. Examples of the (meth)acrylic monomer include those described below for the (meth)acrylic polymer (A).
（(メタ)アクリル系ポリマー（Ａ））
　(メタ)アクリル系ポリマー（Ａ）は、例えば、アルキル（メタ）アクリレートに由来する構成単位を有していてもよく、当該構成単位を主成分として有していてもよい。（メタ）アクリル系ポリマー（Ａ）の主骨格を形成するためのアルキル（メタ）アクリレートに含まれるアルキル基の炭素数は、特に限定されず、例えば１～１８である。このアルキル基は、直鎖状であってもよく、分岐鎖状であってもよく、環状であってもよい。アルキル基としては、例えば、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、アミル基、ヘキシル基、シクロヘキシル基、ヘプチル基、２－エチルヘキシル基、イソオクチル基、ノニル基、デシル基、イソデシル基、ドデシル基、イソミリスチル基、ラウリル基、トリデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基、オクタデシル基などが挙げられる。アルキル（メタ）アクリレートは、単独で又は組み合わせて使用できる。アルキル基の平均炭素数は３～９であることが好ましい。 ((Meth)acrylic polymer (A))
The (meth)acrylic polymer (A) may have, for example, a structural unit derived from an alkyl (meth)acrylate, or may have the structural unit as a main component. The number of carbon atoms of the alkyl group contained in the alkyl (meth)acrylate for forming the main skeleton of the (meth)acrylic polymer (A) is not particularly limited, and is, for example, 1 to 18. The alkyl group may be linear, branched, or cyclic. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group, a hexyl group, a cyclohexyl group, a heptyl group, a 2-ethylhexyl group, an isooctyl group, a nonyl group, a decyl group, an isodecyl group, a dodecyl group, an isomyristyl group, a lauryl group, a tridecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. The alkyl (meth)acrylate may be used alone or in combination. The average number of carbon atoms of the alkyl group is preferably 3 to 9.
　（メタ）アクリル系ポリマー（Ａ）において、アルキル（メタ）アクリレートに由来する構成単位の含有率は、粘着シートの接着性を向上させる観点から、例えば５０重量％以上、好ましくは６０重量％以上、より好ましくは７０重量％以上、更に好ましくは８０重量％以上である。ただし、（メタ）アクリル系ポリマー（Ａ）おける構成単位の含有率は、場合によっては、５０重量％未満であってもよく、３０重量％以下、さらには１０重量％以下であってもよい。 In the (meth)acrylic polymer (A), the content of the structural units derived from alkyl (meth)acrylate is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, and even more preferably 80% by weight or more, from the viewpoint of improving the adhesiveness of the pressure-sensitive adhesive sheet. However, the content of the structural units in the (meth)acrylic polymer (A) may be less than 50% by weight, 30% by weight or less, or even 10% by weight or less, depending on the circumstances.
　（メタ）アクリル系ポリマー（Ａ）を構成する単量体としては、アルキル（メタ）アクリレート以外に、エーテル基含有単量体、カルボキシル基含有単量体、水酸基含有単量体、アミド基含有単量体、芳香環含有単量体などの共重合単量体が挙げられる。共重合単量体は、単独で又は組み合わせて使用できる。 In addition to alkyl (meth)acrylates, examples of monomers constituting the (meth)acrylic polymer (A) include copolymerizable monomers such as ether group-containing monomers, carboxyl group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, and aromatic ring-containing monomers. The copolymerizable monomers can be used alone or in combination.
　（メタ）アクリル系ポリマー（Ａ）は、エーテル基含有単量体に由来する構成単位を含むことが好ましい。エーテル基含有単量体は、その構造中にエーテル基を含み、かつ（メタ）アクリロイル基、ビニル基などの重合性不飽和二重結合を含む化合物である。 The (meth)acrylic polymer (A) preferably contains a structural unit derived from an ether group-containing monomer. The ether group-containing monomer is a compound that contains an ether group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group.
　エーテル基含有単量体は、アルコキシ基含有単量体を含むことが好ましい。アルコキシ基含有単量体は、例えば、下記式（１）で表されるアルキレンオキサイド付加物である。式（１）のＲ1は、水素原子又はメチル基である。式（１）のＲ2は、アルキル基である。アルキル基は、直鎖状であっても分岐を有していてもよい。Ｒ2は、好ましくは直鎖状のアルキル基である。Ｒ2の例は、メチル基及びエチル基である。式（１）のｎは、１～３０の整数であり、好ましくは１～１２の整数であり、１～５の整数であってもよい。
Figure JPOXMLDOC01-appb-C000001
 The ether group-containing monomer preferably includes an alkoxy group-containing monomer. The alkoxy group-containing monomer is, for example, an alkylene oxide adduct represented by the following formula (1). R 1 in formula (1) is a hydrogen atom or a methyl group. R 2 in formula (1) is an alkyl group. The alkyl group may be linear or branched. R 2 is preferably a linear alkyl group. Examples of R 2 are a methyl group and an ethyl group. n in formula (1) is an integer of 1 to 30, preferably an integer of 1 to 12, and may be an integer of 1 to 5.
Figure JPOXMLDOC01-appb-C000001
　式（１）に示すアルキレンオキサイド付加物の例は、２－メトキシエチル（メタ）アクリレート、２－エトキシエチル（メタ）アクリレート、２－（２－エトキシエトキシ）エチル（メタ）アクリレート、メトキシトリエチレングリコール（メタ）アクリレート及びメトキシポリエチレングリコール（メタ）アクリレートである。アルコキシ基含有単量体は、２－メトキシエチルアクリレート（ＭＥＡ）を含むことが好ましい。 Examples of the alkylene oxide adduct shown in formula (1) are 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and methoxypolyethylene glycol (meth)acrylate. The alkoxy group-containing monomer preferably includes 2-methoxyethyl acrylate (MEA).
　エーテル基含有単量体は、上記のアルキレンオキサイド付加物に限定されない。エーテル基含有単量体は、環構造を有していてもよく、当該環構造がエーテル基を有していてもよい。環構造は、エーテル基以外の官能基を含んでいなくてもよい。エーテル基を有する環構造としては、テトラヒドロフラン環、ジオキサン環などが挙げられる。環構造を有するエーテル基含有単量体の例は、環状トリメチロールプロパンホルマール（メタ）アクリレート及びテトラヒドロフルフリル（メタ）アクリレートである。 The ether group-containing monomer is not limited to the alkylene oxide adducts described above. The ether group-containing monomer may have a ring structure, and the ring structure may have an ether group. The ring structure may not contain functional groups other than the ether group. Examples of ring structures having an ether group include a tetrahydrofuran ring and a dioxane ring. Examples of ether group-containing monomers having a ring structure are cyclic trimethylolpropane formal (meth)acrylate and tetrahydrofurfuryl (meth)acrylate.
　（メタ）アクリル系ポリマー（Ａ）において、エーテル基含有単量体に由来する構成単位の含有率は、特に限定されず、例えば２５重量％以上であり、好ましくは３０重量％以上であり、４０重量％以上、５０重量％以上、６０重量％以上、７０重量％以上、８０重量％以上、さらには９０重量％以上であってもよい。含有率の上限は、例えば９９重量％以下であり、場合によっては、８０重量％以下であってもよく、７０重量％以下であってもよい。 In the (meth)acrylic polymer (A), the content of the constituent units derived from the ether group-containing monomer is not particularly limited, and may be, for example, 25% by weight or more, preferably 30% by weight or more, and may be 40% by weight or more, 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, or even 90% by weight or more. The upper limit of the content is, for example, 99% by weight or less, and in some cases may be 80% by weight or less, or 70% by weight or less.
　カルボキシル基含有単量体は、その構造中にカルボキシル基を含み、かつ（メタ）アクリロイル基、ビニル基などの重合性不飽和二重結合を含む化合物である。カルボキシル基含有単量体としては、例えば、(メタ)アクリル酸、カルボキシエチル(メタ)アクリレート、カルボキシペンチル(メタ)アクリレート、イタコン酸、マレイン酸、フマル酸、クロトン酸などが挙げられる。これらの中でも、共重合性、価格、及び粘着シート１の粘着特性を向上させる観点から、アクリル酸が好ましい。 Carboxyl group-containing monomers are compounds that contain a carboxyl group in their structure and also contain a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of carboxyl group-containing monomers include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Among these, acrylic acid is preferred from the viewpoints of copolymerizability, cost, and improving the adhesive properties of the adhesive sheet 1.
　（メタ）アクリル系ポリマー（Ａ）において、カルボキシル基含有単量体に由来する構成単位は、架橋剤との反応性が高く、粘着シート１の凝集性や耐熱性の向上に寄与する。カルボキシル基含有単量体に由来する構成単位は、粘着シート１について、耐久性とリワーク性を両立させることにも適している。（メタ）アクリル系ポリマー（Ａ）において、カルボキシル基含有単量体に由来する構成単位の含有率は、特に限定されず、例えば１０重量％以下であり、０．０１～８重量％、０．０５～６重量％、さらには０．１～５重量％であることが好ましい。カルボキシル基含有単量体に由来する構成単位の含有率が０．０１重量％以上である場合、粘着シート１の耐久性が向上する傾向がある。含有率が１０重量％以下である場合、粘着シート１のリワーク性が向上する傾向がある。 In the (meth)acrylic polymer (A), the constituent units derived from the carboxyl group-containing monomer have high reactivity with the crosslinking agent, and contribute to improving the cohesiveness and heat resistance of the adhesive sheet 1. The constituent units derived from the carboxyl group-containing monomer are also suitable for achieving both durability and reworkability in the adhesive sheet 1. In the (meth)acrylic polymer (A), the content of the constituent units derived from the carboxyl group-containing monomer is not particularly limited, and is, for example, 10% by weight or less, and is preferably 0.01 to 8% by weight, 0.05 to 6% by weight, or even 0.1 to 5% by weight. When the content of the constituent units derived from the carboxyl group-containing monomer is 0.01% by weight or more, the durability of the adhesive sheet 1 tends to improve. When the content is 10% by weight or less, the reworkability of the adhesive sheet 1 tends to improve.
　水酸基含有単量体は、その構造中に水酸基を含み、かつ（メタ）アクリロイル基、ビニル基などの重合性不飽和二重結合を含む化合物である。水酸基含有単量体としては、例えば、２－ヒドロキシエチル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、６－ヒドロキシヘキシル（メタ）アクリレート、８－ヒドロキシオクチル（メタ）アクリレート、１０－ヒドロキシデシル（メタ）アクリレート、１２－ヒドロキシラウリル（メタ）アクリレートなどの水酸基含有アルキル（メタ）アクリレート；（４－ヒドロキシメチルシクロヘキシル）－メチルアクリレートなどの水酸基含有シクロアルキル（メタ）アクリレートが挙げられる。これらの中でも、耐久性の点から２－ヒドロキシエチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレートが好ましい。 Hydroxyl-containing monomers are compounds that contain hydroxyl groups in their structure and polymerizable unsaturated double bonds such as (meth)acryloyl groups and vinyl groups. Examples of hydroxyl-containing monomers include hydroxyl-containing alkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate; and hydroxyl-containing cycloalkyl (meth)acrylates such as (4-hydroxymethylcyclohexyl)-methylacrylate. Among these, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred from the standpoint of durability.
　カルボキシル基含有単量体と同様に、水酸基含有単量体に由来する構成単位は、架橋剤との反応性が高く、粘着シート１の凝集性や耐熱性の向上に寄与する。水酸基含有単量体に由来する構成単位は、粘着シート１について、リワーク性を向上させることにも適している。（メタ）アクリル系ポリマー（Ａ）において、水酸基含有単量体に由来する構成単位の含有率は、特に限定されず、例えば３重量％以下であり、０．０１～３重量％、０．１～２重量％、さらには０．２～２重量％であることが好ましい。水酸基含有単量体に由来する構成単位の含有率が０．０１重量％以上である場合、架橋剤との反応性が向上するとともに、粘着シート１の耐久性や粘着特性も向上する傾向がある。さらに、粘着シート１の耐久性の観点から、水酸基含有単量体に由来する構成単位の含有率は３重量％以下であることが好ましい。 Similar to carboxyl group-containing monomers, the structural units derived from hydroxyl group-containing monomers are highly reactive with crosslinking agents and contribute to improving the cohesiveness and heat resistance of the adhesive sheet 1. The structural units derived from hydroxyl group-containing monomers are also suitable for improving the reworkability of the adhesive sheet 1. In the (meth)acrylic polymer (A), the content of the structural units derived from hydroxyl group-containing monomers is not particularly limited, and is, for example, 3% by weight or less, and is preferably 0.01 to 3% by weight, 0.1 to 2% by weight, or even 0.2 to 2% by weight. When the content of the structural units derived from hydroxyl group-containing monomers is 0.01% by weight or more, the reactivity with the crosslinking agent is improved, and the durability and adhesive properties of the adhesive sheet 1 also tend to be improved. Furthermore, from the viewpoint of the durability of the adhesive sheet 1, the content of the structural units derived from hydroxyl group-containing monomers is preferably 3% by weight or less.
　アミド基含有単量体は、その構造中にアミド基を含み、かつ（メタ）アクリロイル基、ビニル基などの重合性不飽和二重結合を含む化合物である。アミド基含有単量体としては、例えば、（メタ）アクリルアミド、Ｎ，Ｎ－ジメチル（メタ）アクリルアミド、Ｎ，Ｎ－ジエチル（メタ）アクリルアミド、Ｎ－イソプロピルアクリルアミド、Ｎ－メチル（メタ）アクリルアミド、Ｎ－ブチル（メタ）アクリルアミド、Ｎ－ヘキシル（メタ）アクリルアミド、Ｎ－メチロール（メタ）アクリルアミド、Ｎ－メチロール－Ｎ－プロパン（メタ）アクリルアミド、アミノメチル（メタ）アクリルアミド、アミノエチル（メタ）アクリルアミド、メルカプトメチル（メタ）アクリルアミド、メルカプトエチル（メタ）アクリルアミドなどのアクリルアミド系単量体；Ｎ－（メタ）アクリロイルモルホリン、Ｎ－（メタ）アクリロイルピペリジン、Ｎ－（メタ）アクリロイルピロリジンなどのＮ－アクリロイル複素環単量体；Ｎ－ビニルピロリドン、Ｎ－ビニル－ε－カプロラクタムなどのＮ－ビニル基含有ラクタム系単量体などが挙げられる。これらの中でも、粘着シート１の表面抵抗値が多湿環境下などで経時的に上昇することを抑制する観点から、Ｎ－ビニル基含有ラクタム系単量体が好ましい。 An amide group-containing monomer is a compound that contains an amide group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of the amide group-containing monomer include acrylamide-based monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropylacrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylol-N-propane(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, and mercaptoethyl(meth)acrylamide; N-acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, and N-(meth)acryloylpyrrolidine; and N-vinyl group-containing lactam-based monomers such as N-vinylpyrrolidone and N-vinyl-ε-caprolactam. Among these, N-vinyl group-containing lactam monomers are preferred from the viewpoint of suppressing the surface resistance value of the adhesive sheet 1 from increasing over time in a humid environment, etc.
　（メタ）アクリル系ポリマー（Ａ）において、アミド基含有単量体に由来する構成単位の含有率は、偏光フィルム２と粘着シート１との投錨力の観点から、１０重量％以下であることが好ましく、さらには５重量％以下であることが好ましい。アミド基含有単量体に由来する構成単位の含有率は、粘着シート１の表面抵抗値が多湿環境下などで経時的に上昇することを抑制する観点から、０．１重量％以上であることが好ましく、０．３重量％以上、さらには０．５重量％以上であることが好ましい。 In the (meth)acrylic polymer (A), the content of the structural unit derived from the amide group-containing monomer is preferably 10% by weight or less, and more preferably 5% by weight or less, from the viewpoint of the anchoring force between the polarizing film 2 and the adhesive sheet 1. The content of the structural unit derived from the amide group-containing monomer is preferably 0.1% by weight or more, and more preferably 0.3% by weight or more, and even more preferably 0.5% by weight or more, from the viewpoint of suppressing an increase in the surface resistance value of the adhesive sheet 1 over time in a humid environment or the like.
　アミド基含有単量体に由来する構成単位は、（メタ）アクリル系ポリマー（Ａ）と帯電防止剤（特にイオン性化合物）との相溶性を向上させることに適している。これらの相溶性が向上することによって、粘着シート１の表面抵抗値が多湿環境下で経時的に上昇することを抑制できる傾向がある。アミド基含有単量体に由来する構成単位は、ガラスや透明導電層（例えばＩＴＯ層）に対する粘着シート１の耐久性を向上させる傾向もある。この粘着シート１によれば、画像表示セルからの光学積層体１０の剥がれや浮きの発生を抑制しやすい。さらに、アミド基含有単量体に由来する構成単位は、多湿環境下での粘着シート１の耐久性の向上に寄与する傾向がある。 The constituent units derived from the amide group-containing monomer are suitable for improving the compatibility between the (meth)acrylic polymer (A) and the antistatic agent (particularly an ionic compound). By improving this compatibility, it tends to be possible to suppress the surface resistance value of the adhesive sheet 1 from increasing over time in a humid environment. The constituent units derived from the amide group-containing monomer also tend to improve the durability of the adhesive sheet 1 against glass and transparent conductive layers (e.g., an ITO layer). This adhesive sheet 1 makes it easy to suppress the occurrence of peeling or lifting of the optical laminate 10 from the image display cell. Furthermore, the constituent units derived from the amide group-containing monomer tend to contribute to improving the durability of the adhesive sheet 1 in a humid environment.
　芳香環含有単量体は、その構造中に芳香環構造を含み、かつ（メタ）アクリロイル基、ビニル基などの重合性不飽和二重結合を含む化合物である。芳香環としては、例えば、ベンゼン環、ナフタレン環、ビフェニル環などが挙げられる。芳香環含有単量体は、好ましくは芳香環含有（メタ）アクリレートである。 The aromatic ring-containing monomer is a compound that contains an aromatic ring structure in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of aromatic rings include a benzene ring, a naphthalene ring, and a biphenyl ring. The aromatic ring-containing monomer is preferably an aromatic ring-containing (meth)acrylate.
　芳香環含有（メタ）アクリレートとしては、例えば、ベンジル（メタ）アクリレート、フェニル（メタ）アクリレート、ｏ－フェニルフェノール（メタ）アクリレート、フェノキシ（メタ）アクリレート、フェノキシエチル（メタ）アクリレート、フェノキシプロピル（メタ）アクリレート、フェノキシジエチレングリコール（メタ）アクリレート、エチレンオキサイド変性ノニルフェノール（メタ）アクリレート、エチレンオキサイド変性クレゾール（メタ）アクリレート、フェノールエチレンオキサイド変性（メタ）アクリレート、２－ヒドロキシ－３－フェノキシプロピル（メタ）アクリレート、メトキシベンジル（メタ）アクリレート、クロロベンジル（メタ）アクリレート、クレジル（メタ）アクリレート、ポリスチリル（メタ）アクリレートなどのベンゼン環を有するもの；ヒドロキシエチル化β－ナフトールアクリレート、２－ナフトエチル（メタ）アクリレート、２－ナフトキシエチルアクリレート、２－（４－メトキシ－１－ナフトキシ）エチル（メタ）アクリレートなどのナフタレン環を有するもの；ビフェニル（メタ）アクリレートなどのビフェニル環を有するものなどが挙げられる。これらの中でも、粘着シート１の粘着特性や耐久性を向上させる観点から、ベンジル（メタ）アクリレート、フェノキシエチル（メタ）アクリレートが好ましい。 Examples of aromatic ring-containing (meth)acrylates include benzyl (meth)acrylate, phenyl (meth)acrylate, o-phenylphenol (meth)acrylate, phenoxy (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxypropyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide-modified nonylphenol (meth)acrylate, ethylene oxide-modified cresol (meth)acrylate, phenol ethylene oxide-modified (meth)acrylate, 2-hydroxy Examples of such acrylates include those having a benzene ring, such as 3-phenoxypropyl (meth)acrylate, methoxybenzyl (meth)acrylate, chlorobenzyl (meth)acrylate, cresyl (meth)acrylate, and polystyryl (meth)acrylate; those having a naphthalene ring, such as hydroxyethylated β-naphthol acrylate, 2-naphthoethyl (meth)acrylate, 2-naphthoxyethyl acrylate, and 2-(4-methoxy-1-naphthoxy)ethyl (meth)acrylate; and those having a biphenyl ring, such as biphenyl (meth)acrylate. Among these, benzyl (meth)acrylate and phenoxyethyl (meth)acrylate are preferred from the viewpoint of improving the adhesive properties and durability of the adhesive sheet 1.
　（メタ）アクリル系ポリマー（Ａ）において、芳香環含有単量体に由来する構成単位の含有率は、特に限定されず、例えば２５重量％以下であり、３～２５重量％、１０～２２重量％、さらには１４～２０重量％であることが好ましい。芳香環含有単量体に由来する構成単位の含有率が３重量％以上である場合、画像表示装置の表示ムラを抑制できる傾向がある。含有率が２５重量％以下である場合、粘着シート１の耐久性を向上できる傾向がある。 In the (meth)acrylic polymer (A), the content of the structural unit derived from the aromatic ring-containing monomer is not particularly limited, and is, for example, 25% by weight or less, and preferably 3 to 25% by weight, 10 to 22% by weight, or even 14 to 20% by weight. When the content of the structural unit derived from the aromatic ring-containing monomer is 3% by weight or more, there is a tendency that display unevenness of the image display device can be suppressed. When the content is 25% by weight or less, there is a tendency that the durability of the adhesive sheet 1 can be improved.
　（メタ）アクリル系ポリマー（Ａ）を構成する単量体としては、アルキル（メタ）アクリレート及び上記の共重合単量体以外にも、粘着シート１の接着性、耐熱性の改善を目的に、（メタ）アクリロイル基又はビニル基などの不飽和二重結合を含む重合性官能基を有する他の共重合単量体を用いることができる。他の共重合単量体は、単独で又は組み合わせて使用できる。 In addition to the alkyl (meth)acrylate and the above-mentioned copolymerizing monomers, other copolymerizing monomers having a polymerizable functional group containing an unsaturated double bond, such as a (meth)acryloyl group or a vinyl group, can be used as the monomers constituting the (meth)acrylic polymer (A) in order to improve the adhesiveness and heat resistance of the adhesive sheet 1. The other copolymerizing monomers can be used alone or in combination.
　他の共重合単量体としては、例えば、無水マレイン酸、無水イタコン酸などの酸無水物基含有単量体；アクリル酸のカプロラクトン付加物；アリルスルホン酸、２－（メタ）アクリルアミド－２－メチルプロパンスルホン酸、（メタ）アクリルアミドプロパンスルホン酸、スルホプロピル（メタ）アクリレートなどのスルホン酸基含有単量体；２－ヒドロキシエチルアクリロイルホスフェートなどのリン酸基含有単量体；アミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリレート、ｔ－ブチルアミノエチル（メタ）アクリレートなどのアルキルアミノアルキル（メタ）アクリレート；メトキシエチル（メタ）アクリレート、エトキシエチル（メタ）アクリレートなどのアルコキシアルキル（メタ）アクリレート；Ｎ－（メタ）アクリロイルオキシメチレンスクシンイミド、Ｎ－（メタ）アクリロイル－６－オキシヘキサメチレンスクシンイミド、Ｎ－（メタ）アクリロイル－８－オキシオクタメチレンスクシンイミドなどのスクシンイミド系単量体；Ｎ－シクロヘキシルマレイミド、Ｎ－イソプロピルマレイミド、Ｎ－ラウリルマレイミド、Ｎ－フェニルマレイミドなどのマレイミド系単量体；Ｎ－メチルイタコンイミド、Ｎ－エチルイタコンイミド、Ｎ－ブチルイタコンイミド、Ｎ－オクチルイタコンイミド、Ｎ－２－エチルヘキシルイタコンイミド、Ｎ－シクロヘキシルイタコンイミド、Ｎ－ラウリルイタコンイミドなどのイタコンイミド系単量体；酢酸ビニル、プロピオン酸ビニルなどのビニル系単量体；アクリロニトリル、メタクリロニトリルなどのシアノアクリレート系単量体；グリシジル（メタ）アクリレートなどのエポキシ基含有（メタ）アクリレート；ポリエチレングリコール（メタ）アクリレート、ポリプロピレングリコール（メタ）アクリレート、メトキシエチレングリコール（メタ）アクリレート、メトキシポリプロピレングリコール（メタ）アクリレートなどのグリコール系（メタ）アクリレート；テトラヒドロフルフリル（メタ）アクリレート、フッ素（メタ）アクリレート、シリコーン（メタ）アクリレート、２－メトキシエチルアクリレートなどの（メタ）アクリレート単量体；イソプレン、ブタジエン、イソブチレン、ビニルエーテルなどのビニル基含有単量体；３－アクリロキシプロピルトリエトキシシラン、ビニルトリメトキシシラン、ビニルトリエトキシシラン、４－ビニルブチルトリメトキシシラン、４－ビニルブチルトリエトキシシラン、８－ビニルオクチルトリメトキシシラン、８－ビニルオクチルトリエトキシシラン、１０－メタクリロイルオキシデシルトリメトキシシラン、１０－アクリロイルオキシデシルトリメトキシシラン、１０－メタクリロイルオキシデシルトリエトキシシラン、１０－アクリロイルオキシデシルトリエトキシシランなどのケイ素原子を含有するシラン系単量体などが挙げられる。 Other copolymerizable monomers include, for example, acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; sulfonic acid group-containing monomers such as allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, and sulfopropyl (meth)acrylate; phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; alkylaminoalkyl (meth)acrylates such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; methoxyethyl (meth)acrylate, ethoxyethyl alkoxyalkyl (meth)acrylates such as N-(meth)acryloyloxymethylene succinimide, N-(meth)acryloyl-6-oxyhexamethylene succinimide, N-(meth)acryloyl-8-oxyoctamethylene succinimide, and other succinimide monomers; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylatconimide, and other vinyl acetate, vinyl propionate, and other vinyl monomers; cyanoacrylate monomers, such as acrylonitrile and methacrylonitrile; epoxy group-containing (meth)acrylates, such as glycidyl (meth)acrylate; glycol (meth)acrylates, such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; (meth)acrylates, such as tetrahydrofurfuryl (meth)acrylate, fluorine (meth)acrylate, silicone (meth)acrylate, and 2-methoxyethyl acrylate; p) Acrylate monomers; vinyl group-containing monomers such as isoprene, butadiene, isobutylene, and vinyl ether; silane monomers containing silicon atoms such as 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, and 10-acryloyloxydecyltriethoxysilane.
　さらに、他の共重合単量体としては、例えば、トリプロピレングリコールジ（メタ）アクリレート、テトラエチレングリコールジ（メタ）アクリレート、１，６－ヘキサンジオールジ（メタ）アクリレート、ビスフェノールＡジグリシジルエーテルジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、ジペンタエリスリトールペンタ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、カプロラクトン変性ジペンタエリスリトールヘキサ（メタ）アクリレート、ポリエステル（メタ）アクリレート、エポキシ（メタ）アクリレート、ウレタン（メタ）アクリレートなどの不飽和二重結合を２個以上有する多官能性単量体が挙げられる。 Furthermore, examples of other copolymerizable monomers include polyfunctional monomers having two or more unsaturated double bonds, such as tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, polyester (meth)acrylate, epoxy (meth)acrylate, and urethane (meth)acrylate.
　他の共重合単量体を使用する場合、（メタ）アクリル系ポリマー（Ａ）において、他の共重合単量体に由来する構成単位の含有率は、１０重量％以下であることが好ましく、７重量％以下であることがより好ましく、５重量％以下であることがさらに好ましい。 When other copolymerization monomers are used, the content of structural units derived from the other copolymerization monomers in the (meth)acrylic polymer (A) is preferably 10% by weight or less, more preferably 7% by weight or less, and even more preferably 5% by weight or less.
　（メタ）アクリル系ポリマー（Ａ）の重量平均分子量は、通常、３０万～４００万である。耐久性の観点から、（メタ）アクリル系ポリマー（Ａ）の重量平均分子量は、１００万以上であることが好ましく、１５０万以上であってもよい。（メタ）アクリル系ポリマー（Ａ）の重量平均分子量は、３００万以下であってもよく、２００万以下であってもよい。重量平均分子量が３０万以上であることが、耐熱性の点で好ましい。重量平均分子量が４００万以下であると、粘着シートが硬くなりにくく、剥がれが発生しにくい傾向がある。分子量分布を意味する重量平均分子量（Ｍｗ）／数平均分子量（Ｍｎ）は、１．８～１０であることが好ましく、１．８～７であることがより好ましく、１．８～５であることがさらに好ましい。分子量分布（Ｍｗ／Ｍｎ）が１０以下であることが、耐久性の点で好ましい。重量平均分子量、分子量分布（Ｍｗ／Ｍｎ）は、ＧＰＣ（ゲル・パーミエーション・クロマトグラフィー）により測定し、ポリスチレン換算により算出された値から求められる。 The weight average molecular weight of the (meth)acrylic polymer (A) is usually 300,000 to 4,000,000. From the viewpoint of durability, the weight average molecular weight of the (meth)acrylic polymer (A) is preferably 1,000,000 or more, and may be 1,500,000 or more. The weight average molecular weight of the (meth)acrylic polymer (A) may be 3,000,000 or less, and may be 2,000,000 or less. A weight average molecular weight of 300,000 or more is preferable from the viewpoint of heat resistance. If the weight average molecular weight is 4,000,000 or less, the adhesive sheet tends not to become hard and peeling does not occur easily. The weight average molecular weight (Mw)/number average molecular weight (Mn), which means the molecular weight distribution, is preferably 1.8 to 10, more preferably 1.8 to 7, and even more preferably 1.8 to 5. From the viewpoint of durability, it is preferable that the molecular weight distribution (Mw/Mn) is 10 or less. The weight average molecular weight and the molecular weight distribution (Mw/Mn) are measured by GPC (gel permeation chromatography) and calculated from the polystyrene equivalent.
　（メタ）アクリル系ポリマー（Ａ）は、溶液重合、電子線やＵＶなどの放射線重合、塊状重合、乳化重合などの各種ラジカル重合などの公知の重合方法によって作製できる。得られる（メタ）アクリル系ポリマー（Ａ）は、ランダム共重合体、ブロック共重合体、グラフト共重合体などのいずれでもよい。 The (meth)acrylic polymer (A) can be produced by known polymerization methods such as solution polymerization, radiation polymerization using electron beams or UV rays, bulk polymerization, emulsion polymerization, and other radical polymerizations. The resulting (meth)acrylic polymer (A) may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.
　溶液重合においては、重合溶媒として、例えば、酢酸エチル、トルエンなどが用いられる。溶液重合は、例えば、窒素などの不活性ガス気流下で重合開始剤を加え、通常、５０～７０℃程度で５～３０時間程度の反応条件で行われる。 In solution polymerization, for example, ethyl acetate, toluene, etc. are used as the polymerization solvent. Solution polymerization is usually carried out under reaction conditions of about 50 to 70°C for about 5 to 30 hours, with a polymerization initiator added under a stream of inert gas such as nitrogen.
　ラジカル重合に用いられる重合開始剤、連鎖移動剤、乳化剤などは、特に限定されず適宜選択して使用することができる。（メタ）アクリル系ポリマー（Ａ）の重量平均分子量は、重合開始剤、連鎖移動剤の使用量、反応条件などにより制御可能である。そのため、重合開始剤及び連鎖移動剤については、その組成に応じてその使用量が適宜調整される。 The polymerization initiator, chain transfer agent, emulsifier, etc. used in the radical polymerization are not particularly limited and can be appropriately selected and used. The weight average molecular weight of the (meth)acrylic polymer (A) can be controlled by the amount of polymerization initiator and chain transfer agent used, reaction conditions, etc. Therefore, the amount of polymerization initiator and chain transfer agent used is appropriately adjusted depending on the composition.
　重合開始剤の例は、２，２’－アゾビスイソブチロニトリル、２，２’－アゾビス（２－アミジノプロパン）ジヒドロクロライド、２，２’－アゾビス［２－（５－メチル－２－イミダゾリン－２－イル）プロパン］ジヒドロクロライド、２，２’－アゾビス（２－メチルプロピオンアミジン）二硫酸塩、２，２’－アゾビス（Ｎ，Ｎ’－ジメチレンイソブチルアミジン）、２，２’－アゾビス［Ｎ－（２－カルボキシエチル）－２－メチルプロピオンアミジン］ハイドレート（例えば、和光純薬社製ＶＡ－０５７）等のアゾ系開始剤；過硫酸カリウム、過硫酸アンモニウム等の過硫酸塩；ジ（２－エチルヘキシル）パーオキシジカーボネート、ジ（４－ｔ－ブチルシクロヘキシル）パーオキシジカーボネート、ジ－ｓｅｃ－ブチルパーオキシジカーボネート、ｔ－ブチルパーオキシネオデカノエート、ｔ－ヘキシルパーオキシピバレート、ｔ－ブチルパーオキシピバレート、ジラウロイルパーオキシド、ジ－ｎ－オクタノイルパーオキシド、１，１，３，３－テトラメチルブチルパーオキシ－２－エチルヘキサノエート、ジ（４－メチルベンゾイル）パーオキシド、ジベンゾイルパーオキシド、ｔ－ブチルパーオキシイソブチレート、１，１－ジ（ｔ－ヘキシルパーオキシ）シクロヘキサン、ｔ－ブチルハイドロパーオキシド、過酸化水素等の過酸化物系開始剤；過硫酸塩及び亜硫酸水素ナトリウムの組み合わせ、過酸化物及びアスコルビン酸ナトリウムの組み合わせ等、過酸化物及び還元剤を組み合わせたレドックス系開始剤である。ただし、重合開始剤は、上記例に限定されない。 Examples of polymerization initiators include azo initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane)dihydrochloride, 2,2'-azobis[2-(5-methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis(2-methylpropionamidine)disulfate, 2,2'-azobis(N,N'-dimethyleneisobutylamidine), and 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]hydrate (e.g., VA-057 manufactured by Wako Pure Chemical Industries, Ltd.); persulfates such as potassium persulfate and ammonium persulfate; di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di- Peroxide-based initiators such as sec-butyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, di(4-methylbenzoyl)peroxide, dibenzoyl peroxide, t-butyl peroxyisobutyrate, 1,1-di(t-hexylperoxy)cyclohexane, t-butyl hydroperoxide, and hydrogen peroxide; redox-based initiators that combine peroxides and reducing agents, such as a combination of persulfates and sodium hydrogen sulfite, or a combination of peroxides and sodium ascorbate. However, the polymerization initiator is not limited to the above examples.
　重合開始剤は、単独で又は２種以上を組み合わせて使用できる。重合開始剤の使用量は、合計で、単量体成分１００重量部に対して、例えば０．００５～１重量部であり、０．０２～０．５重量部であってもよい。 The polymerization initiators can be used alone or in combination of two or more. The total amount of polymerization initiator used is, for example, 0.005 to 1 part by weight, or may be 0.02 to 0.5 parts by weight, per 100 parts by weight of the monomer component.
　連鎖移動剤の例は、ラウリルメルカプタン、グリシジルメルカプタン、メルカプト酢酸、２－メルカプトエタノール、チオグリコール酸、チオグリコール酸２－エチルヘキシル、及び２，３－ジメルカプト－１－プロパノールである。連鎖移動剤は、単独で又は２種以上を組み合わせて使用できる。連鎖移動剤の使用量は、合計で、単量体成分１００重量部に対して、例えば０．１重量部以下である。 Examples of chain transfer agents are lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol. The chain transfer agents can be used alone or in combination of two or more. The total amount of chain transfer agent used is, for example, 0.1 parts by weight or less per 100 parts by weight of the monomer component.
　放射線重合では、単量体群に対して電子線、ＵＶ等の放射線を照射することにより重合を進行させて（メタ）アクリル系ポリマー（Ａ）を形成する。光硬化性組成物から粘着シートを形成する場合は、光硬化性組成物に光を照射することにより重合を進行させて（メタ）アクリル系ポリマー（Ａ）を形成する。放射線重合を電子線で行う場合は、光重合開始剤の使用は特に必要ではない。放射線重合をＵＶで行う場合は、重合時間を短縮できる等の利点から、光重合開始剤を使用してもよい。光重合開始剤は、単独で又は２種以上を組み合わせて使用できる。 In radiation polymerization, the monomer group is irradiated with radiation such as electron beams or UV light to cause polymerization to proceed and form a (meth)acrylic polymer (A). When forming an adhesive sheet from a photocurable composition, the photocurable composition is irradiated with light to cause polymerization to proceed and form a (meth)acrylic polymer (A). When radiation polymerization is performed with electron beams, the use of a photopolymerization initiator is not particularly necessary. When radiation polymerization is performed with UV light, a photopolymerization initiator may be used due to the advantage that the polymerization time can be shortened. The photopolymerization initiators can be used alone or in combination of two or more types.
　光重合開始剤の例は、ベンゾインエーテル系、アセトフェノン系、α－ケトール系、光活性オキシム系、ベンゾイン系、ベンジル系、ベンゾフェノン系、ケタール系、チオキサントン系等の各種の光重合開始剤である。ただし、光重合開始剤は、上記例に限定されない。光重合開始剤の使用量は、単量体成分１００重量部に対して、例えば０．０５～１．５重量部であり、０．１～１重量部であってもよい。 Examples of photopolymerization initiators include various photopolymerization initiators such as benzoin ether, acetophenone, α-ketol, photoactive oxime, benzoin, benzil, benzophenone, ketal, and thioxanthone. However, the photopolymerization initiator is not limited to the above examples. The amount of photopolymerization initiator used is, for example, 0.05 to 1.5 parts by weight, or may be 0.1 to 1 part by weight, per 100 parts by weight of the monomer component.
（帯電防止剤）
　帯電防止剤は、粘着シート１に帯電防止性能を付与できる材料である。帯電防止剤としては、例えば、イオン性界面活性剤、導電性ポリマー、導電性微粒子、イオン性化合物などが挙げられる。 (Antistatic Agent)
The antistatic agent is a material capable of imparting antistatic properties to the pressure-sensitive adhesive sheet 1. Examples of the antistatic agent include ionic surfactants, conductive polymers, conductive fine particles, and ionic compounds.
　イオン性界面活性剤としては、例えば、４級アンモニウム塩型、ホスホニウム塩型、スルホニウム塩型等のカチオン系界面活性剤；カルボン酸型、スルホネート型、サルフェート型、ホスフェート型、ホスファイト型等のアニオン系界面活性剤；スルホベタイン型、アルキルベタイン型、アルキルイミダゾリウムベタイン型等の両性イオン系界面活性剤；多価アルコール誘導体、β－シクロデキストリン包接化合物、ソルビタン脂肪酸モノエステル、ソルビタン脂肪酸ジエステル、ポリアルキレンオキシド誘導体、アミンオキシド等のノニオン系界面活性剤が挙げられる。 Ionic surfactants include, for example, cationic surfactants such as quaternary ammonium salts, phosphonium salts, and sulfonium salts; anionic surfactants such as carboxylic acid, sulfonate, sulfate, phosphate, and phosphite; amphoteric surfactants such as sulfobetaine, alkylbetaine, and alkylimidazolium betaine; and nonionic surfactants such as polyhydric alcohol derivatives, β-cyclodextrin clathrate compounds, sorbitan fatty acid monoesters, sorbitan fatty acid diesters, polyalkylene oxide derivatives, and amine oxides.
　導電性ポリマーとしては、ポリアニリン系、ポリチオフェン系、ポリピロール系、ポリキノキサリン系等のポリマーが挙げられる。これらの中でも、水溶性導電性ポリマー又は水分散性導電性ポリマーとして機能しやすいポリアニリン、ポリチオフェンなどが好ましく、特にポリチオフェンが好ましい。 Conductive polymers include polyaniline, polythiophene, polypyrrole, and polyquinoxaline polymers. Among these, polyaniline and polythiophene, which easily function as water-soluble conductive polymers or water-dispersible conductive polymers, are preferred, with polythiophene being particularly preferred.
　導電性微粒子としては、例えば、酸化スズ系、酸化アンチモン系、酸化インジウム系、酸化亜鉛系等の金属酸化物微粒子が挙げられ、酸化スズ系微粒子が好ましい。酸化スズ系微粒子の材料としては、例えば、酸化スズ、アンチモンドープ酸化スズ、インジウムドープ酸化スズ、アルミニウムドープ酸化スズ、タングステンドープ酸化スズ、酸化チタン－酸化セリウム－酸化スズの複合体、酸化チタン－酸化スズの複合体等が挙げられる。導電性微粒子の平均粒径は、例えば１～１００ｎｍであり、好ましくは２～５０ｎｍである。導電性微粒子の平均粒径は、例えば、レーザー回折式粒度計などによって測定される粒度分布において、体積累積５０％に相当する粒径（ｄ５０）を意味する。 Conductive fine particles include, for example, metal oxide fine particles such as tin oxide, antimony oxide, indium oxide, and zinc oxide, with tin oxide fine particles being preferred. Materials for tin oxide fine particles include, for example, tin oxide, antimony-doped tin oxide, indium-doped tin oxide, aluminum-doped tin oxide, tungsten-doped tin oxide, titanium oxide-cerium oxide-tin oxide composite, and titanium oxide-tin oxide composite. The average particle size of the conductive fine particles is, for example, 1 to 100 nm, and preferably 2 to 50 nm. The average particle size of the conductive fine particles means, for example, the particle size (d50) corresponding to 50% cumulative volume in the particle size distribution measured by a laser diffraction particle sizer or the like.
　帯電防止剤は、イオン性化合物を含むことが好ましい。イオン性化合物は、帯電防止機能の点からイオン液体であることが好ましい。 The antistatic agent preferably contains an ionic compound. From the viewpoint of antistatic function, the ionic compound is preferably an ionic liquid.
　イオン性化合物としては、例えば、アルカリ金属塩及び／又は有機カチオン－アニオン塩が挙げられる。アルカリ金属塩としては、例えば、アルカリ金属の有機塩及び無機塩が挙げられる。粘着シート１中での相溶性の観点から、アルカリ金属塩は、アルカリ金属の有機塩であることが好ましい。本明細書において、有機カチオン－アニオン塩は、有機カチオンを含む有機塩を意味する。有機カチオン－アニオン塩に含まれるアニオンは、有機アニオンであってもよく、無機アニオンであってもよい。粘着シート１中での相溶性の観点から、有機カチオン－アニオン塩に含まれるアニオンは、有機アニオンであることが好ましい。有機カチオン－アニオン塩は、イオン性液体又はイオン性固体と呼ばれることがある。 Examples of the ionic compound include alkali metal salts and/or organic cation-anion salts. Examples of the alkali metal salts include organic and inorganic salts of alkali metals. From the viewpoint of compatibility in the adhesive sheet 1, the alkali metal salt is preferably an organic salt of an alkali metal. In this specification, the organic cation-anion salt means an organic salt containing an organic cation. The anion contained in the organic cation-anion salt may be an organic anion or an inorganic anion. From the viewpoint of compatibility in the adhesive sheet 1, the anion contained in the organic cation-anion salt is preferably an organic anion. The organic cation-anion salt may be called an ionic liquid or an ionic solid.
　アルカリ金属塩に含まれるアルカリ金属イオンとしては、例えば、リチウムイオン、ナトリウムイオン及びカリウムイオンが挙げられ、リチウムイオンが好ましい。 Examples of the alkali metal ions contained in the alkali metal salt include lithium ions, sodium ions, and potassium ions, with lithium ions being preferred.
　アルカリ金属の有機塩に含まれるアニオンとしては、例えば、ＣＨ3ＣＯＯ-、ＣＦ3ＣＯＯ-、ＣＨ3ＳＯ3 -、ＣＦ3ＳＯ3 -、（ＣＦ3ＳＯ2）3Ｃ-、Ｃ4Ｆ9ＳＯ3 -、Ｃ3Ｆ7ＣＯＯ-、（ＣＦ3ＳＯ2）（ＣＦ3ＣＯ）Ｎ-、-Ｏ3Ｓ（ＣＦ2）3ＳＯ3 -、（ＣＮ）2Ｎ-及び下記一般式（ａ）～（ｄ）で表されるアニオンが挙げられる。
（ａ）　（ＣnＦ2n+1ＳＯ2）2Ｎ-　（ただし、ｎは１～１０の整数）
（ｂ）　ＣＦ2（ＣmＦ2mＳＯ2）2Ｎ-　（ただし、ｍは１～１０の整数）
（ｃ）　-Ｏ3Ｓ（ＣＦ2）lＳＯ3 -　（ただし、ｌは１～１０の整数）
（ｄ）　（ＣpＦ2p+1ＳＯ2）Ｎ-（ＣqＦ2q+1ＳＯ2）　（ただし、ｐ及びｑは、互いに独立して１～１０の整数） Examples of anions contained in organic salts of alkali metals include CH3COO- , CF3COO- , CH3SO3- , CF3SO3- , ( CF3SO2 ) 3C- , C4F9SO3-, C3F7COO-, (CF3SO2 ) ( CF3CO ) N- , -O3S ( CF2 ) 3SO3- , ( CN ) 2N- , and anions represented by the following general formulas (a ) to ( d ).
(a) (C n F 2n+1 SO 2 ) 2 N - (where n is an integer from 1 to 10)
(b) CF2 ( CmF2mSO2 ) 2N- ( where m is an integer from 1 to 10)
(c) -O3S ( CF2 ) lSO3- ( where l is an integer from 1 to 10 )
(d) (C p F 2p+1 SO 2 )N - (C q F 2q+1 SO 2 ) (wherein p and q are each independently an integer from 1 to 10).
　アルカリ金属の有機塩に含まれるアニオンは、フッ素原子を含むことが好ましい。フッ素原子を含むアニオンによれば、アルカリ金属の有機塩は、イオン解離性に優れたイオン化合物として機能する。 The anion contained in the organic salt of an alkali metal preferably contains a fluorine atom. When the anion contains a fluorine atom, the organic salt of an alkali metal functions as an ionic compound with excellent ion dissociation properties.
　アルカリ金属の無機塩に含まれるアニオンとしては、例えば、Ｃｌ-、Ｂｒ-、Ｉ-、ＡｌＣｌ4 -、Ａｌ2Ｃｌ7 -、ＢＦ4 -、ＰＦ6 -、ＣｌＯ4 -、ＮＯ3 -、ＡｓＦ6 -、ＳｂＦ6 -、ＮｂＦ6 -、ＴａＦ6 -、（ＦＳＯ2）2Ｎ-、ＣＯ3 2-等が挙げられる。 Examples of anions contained in inorganic salts of alkali metals include Cl- , Br- , I- , AlCl4-, Al2Cl7- , BF4- , PF6- , ClO4- , NO3- , AsF6- , SbF6- , NbF6- , TaF6- , ( FSO2 )2N- , and CO32- .
　アルカリ金属塩に含まれるアニオンとしては、（ＣＦ3ＳＯ2）2Ｎ-、（Ｃ2Ｆ5ＳＯ2）2Ｎ-等の上記の一般式（ａ）で表わされる（ペルフルオロアルキルスルホニル）イミドが好ましく、特に（ＣＦ3ＳＯ2）2Ｎ-で表わされる（トリフルオロメタンスルホニル）イミドが好ましい。 As the anion contained in the alkali metal salt, a (perfluoroalkylsulfonyl)imide represented by the above general formula (a) , such as ( CF3SO2 ) 2N- or ( C2F5SO2 ) 2N- , is preferred, and a ( trifluoromethanesulfonyl )imide represented by ( CF3SO2 ) 2N- is particularly preferred.
　アルカリ金属の有機塩としては、例えば、酢酸ナトリウム、アルギン酸ナトリウム、リグニンスルホン酸ナトリウム、トルエンスルホン酸ナトリウム、ＬｉＣＦ3ＳＯ3、Ｌｉ（ＣＦ3ＳＯ2）2Ｎ、Ｌｉ（Ｃ2Ｆ5ＳＯ2）2Ｎ、Ｌｉ（Ｃ4Ｆ9ＳＯ2）2Ｎ、Ｌｉ（ＣＦ3ＳＯ2）3Ｃ、ＫＯ3Ｓ（ＣＦ2）3ＳＯ3Ｋ、ＬｉＯ3Ｓ（ＣＦ2）3ＳＯ3Ｋ等が挙げられ、好ましくはＬｉＣＦ3ＳＯ3、Ｌｉ（ＣＦ3ＳＯ2）2Ｎ、Ｌｉ（Ｃ2Ｆ5ＳＯ2）2Ｎ、Ｌｉ（Ｃ4Ｆ9ＳＯ2）2Ｎ、Ｌｉ（ＣＦ3ＳＯ2）3Ｃであり、より好ましくはＬｉ（ＣＦ3ＳＯ2）2Ｎ、Ｌｉ（Ｃ2Ｆ5ＳＯ2）2Ｎ、Ｌｉ（Ｃ4Ｆ9ＳＯ2）2Ｎである。アルカリ金属の有機塩は、フッ素含有リチウムイミド塩であることが好ましく、（ペルフルオロアルキルスルホニル）イミドリチウム塩であることが特に好ましい。 Examples of the organic salt of an alkali metal include sodium acetate, sodium alginate, sodium ligninsulfonate, sodium toluenesulfonate , LiCF3SO3 , Li( CF3SO2 ) 2N , Li( C2F5SO2 ) 2N , Li( C4F9SO2 ) 2N , Li( CF3SO2)3C, KO3S(CF2)3SO3K, LiO3S(CF2)3SO3K, and the like. Of these, LiCF3SO3, Li(CF3SO2 ) 2N , Li ( C2F5SO2 ) 2N , Li ( C4F9SO2 ) 2N , Li ( CF3SO2 ) 3C , LiO3S ( CF2 ) 3SO3K , and the like are preferably used . The organic salt of an alkali metal is preferably Li(CF3SO2)2N , Li (C2F5SO2 ) 2N , or Li( C4F9SO2 ) 2N . The organic salt of an alkali metal is preferably a fluorine-containing lithium imide salt, and more preferably a ( perfluoroalkylsulfonyl )imide lithium salt.
　アルカリ金属の無機塩としては、例えば、過塩素酸リチウム及びヨウ化リチウムが挙げられる。 Examples of inorganic salts of alkali metals include lithium perchlorate and lithium iodide.
　有機カチオン－アニオン塩に含まれる有機カチオンとしては、例えば、ピリジニウムカチオン、ピペリジニウムカチオン、ピロリジニウムカチオン、ピロリン骨格を有するカチオン、ピロール骨格を有するカチオン、イミダゾリウムカチオン、テトラヒドロピリミジニウムカチオン、ジヒドロピリミジニウムカチオン、ピラゾリウムカチオン、ピラゾリニウムカチオン、テトラアルキルアンモニウムカチオン、トリアルキルスルホニウムカチオン、テトラアルキルホスホニウムカチオン等が挙げられる。 Examples of organic cations contained in the organic cation-anion salt include pyridinium cation, piperidinium cation, pyrrolidinium cation, cations having a pyrroline skeleton, cations having a pyrrole skeleton, imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation, pyrazolium cation, pyrazolinium cation, tetraalkylammonium cation, trialkylsulfonium cation, tetraalkylphosphonium cation, etc.
　有機カチオン－アニオン塩に含まれるアニオンとしては、例えば、Ｃｌ-、Ｂｒ-、Ｉ-、ＡｌＣｌ4 -、Ａｌ2Ｃｌ7 -、ＢＦ4 -、ＰＦ6 -、ＣｌＯ4 -、ＮＯ3 -、ＣＨ3ＣＯＯ-、ＣＦ3ＣＯＯ-、ＣＨ3ＳＯ3 -、ＣＦ3ＳＯ3 -、（ＣＦ3ＳＯ2）3Ｃ-、ＡｓＦ6 -、ＳｂＦ6 -、ＮｂＦ6 -、ＴａＦ6 -、（ＣＮ）2Ｎ-、Ｃ4Ｆ9ＳＯ3 -、Ｃ3Ｆ7ＣＯＯ-、（ＣＦ3ＳＯ2）（ＣＦ3ＣＯ）Ｎ-、（ＦＳＯ2）2Ｎ-、-Ｏ3Ｓ（ＣＦ2）3ＳＯ3 -、（ＦＳＯ2）2Ｎ-及び上述した一般式（ａ）～（ｄ）で表されるアニオンが挙げられる。有機カチオン－アニオン塩に含まれるアニオンは、フッ素原子を含むことが好ましい。フッ素原子を含むアニオンによれば、有機カチオン－アニオン塩は、イオン解離性に優れたイオン化合物として機能する。 Examples of anions contained in the organic cation-anion salt include Cl- , Br- , I- , AlCl4- , Al2Cl7- , BF4- , PF6- , ClO4- , NO3- , CH3COO- , CF3COO- , CH3SO3-, CF3SO3- , ( CF3SO2 ) 3C- , AsF6- , SbF6- , NbF6- , TaF6- , ( CN ) 2N- , C4F9SO3- , C3F7COO- , ( CF3SO2 ) ( CF3CO ) N- , ( FSO2 ) 2N- , -O3S ( CF2 ) 3SO3- , ( FSO2 ) 2N- and the anions represented by the above general formulas (a) to (d) are included. The anion contained in the organic cation-anion salt preferably contains a fluorine atom. When the anion contains a fluorine atom, the organic cation-anion salt functions as an ionic compound with excellent ion dissociation properties.
　イオン性化合物としては、上述したアルカリ金属塩及び有機カチオン－アニオン塩に限定されず、例えば、塩化アンモニウム、塩化アルミニウム、塩化銅、塩化第一鉄、塩化第二鉄、硫酸アンモニウム等の無機塩も挙げられる。イオン性化合物は、単独で又は組み合わせて使用できる。 Ionic compounds are not limited to the above-mentioned alkali metal salts and organic cation-anion salts, but also include inorganic salts such as ammonium chloride, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, and ammonium sulfate. Ionic compounds can be used alone or in combination.
　イオン性化合物において、カチオンの分子量は、高温環境下での導通不良を抑制する観点から、例えば２１０以下であり、１５０以下、１１０以下、５０以下、さらには１０以下であることが好ましい。カチオンの分子量が小さいほど、粘着シート１が柔らかくなりにくく、高温環境下での導通不良を抑制できる傾向がある。カチオンの分子量が小さいと、粘着シート１の表面抵抗値が低下しやすく、静電気ムラを抑制できる傾向もある。 In the ionic compound, the molecular weight of the cation is, for example, 210 or less, and preferably 150 or less, 110 or less, 50 or less, or even 10 or less, from the viewpoint of suppressing poor conduction in a high-temperature environment. The smaller the molecular weight of the cation, the less likely the adhesive sheet 1 is to become soft, and there is a tendency for poor conduction in a high-temperature environment to be suppressed. When the molecular weight of the cation is small, the surface resistance value of the adhesive sheet 1 is more likely to decrease, and there is also a tendency for static electricity unevenness to be suppressed.
　なお、リチウム、ナトリウム、カリウムは、いずれも分子量が２１０以下である。そのため、これらのアルカリ金属イオンをカチオンとして含むアルカリ金属塩を好適に用いることができる。特に、アルカリ金属イオンとしては、分子量が最も小さいリチウムイオンが好ましい。イオン性化合物は、リチウム塩が好ましく、リチウムの有機塩が特に好ましい。有機カチオン－アニオン塩を用いる場合、上述したカチオンのうち、分子量が２１０以下であるものを用いることが好ましい。 Note that lithium, sodium, and potassium all have a molecular weight of 210 or less. Therefore, alkali metal salts containing these alkali metal ions as cations can be suitably used. In particular, the alkali metal ion is preferably the lithium ion, which has the smallest molecular weight. The ionic compound is preferably a lithium salt, and more preferably an organic salt of lithium. When using an organic cation-anion salt, it is preferable to use one of the above-mentioned cations that has a molecular weight of 210 or less.
　帯電防止剤としては、上述した材料に限定されず、例えば、アセチレンブラック、ケッチェンブラック、天然グラファイト、人造グラファイトなどの炭素材料；チタンブラック；４級アンモニウム塩等のカチオン型、ベタイン化合物等の両性イオン型、スルホン酸塩等のアニオン型若しくはグリセリン等のノニオン型のイオン導電性基を有する単量体の単独重合体、又は、当該単量体と他の単量体との共重合体；４級アンモニウム塩基を有するアクリレート又はメタクリレート由来の構造単位を有する重合体等のイオン導電性を有する重合体；ポリエチレンメタクリレート共重合体等の親水性ポリマーをアクリル系樹脂等にアロイ化させたもの（永久帯電防止剤）も挙げられる。 Antistatic agents are not limited to the above-mentioned materials, and examples thereof include carbon materials such as acetylene black, ketjen black, natural graphite, and artificial graphite; titanium black; homopolymers of monomers having ion-conductive groups of cationic type such as quaternary ammonium salts, amphoteric type such as betaine compounds, anionic type such as sulfonates, or nonionic type such as glycerin, or copolymers of said monomers with other monomers; polymers having ion conductivity such as polymers having structural units derived from acrylate or methacrylate having quaternary ammonium bases; and alloys of hydrophilic polymers such as polyethylene methacrylate copolymers with acrylic resins (permanent antistatic agents).
　粘着剤組成物において、帯電防止剤の配合量は、目的とする粘着シート１の表面抵抗値に応じて適宜調節することができ、例えば、(メタ)アクリル系ポリマー（Ａ）１００重量部に対して０．０５～２０重量部である。粘着シート１の帯電防止性能を向上させる観点から、帯電防止剤の配合量は、(メタ)アクリル系ポリマー（Ａ）１００重量部に対して、０．０５重量部以上であることが好ましく、０．１重量部以上、さらには０．５重量部以上であることが好ましい。粘着シート１の耐久性の観点から、帯電防止剤の配合量は、(メタ)アクリル系ポリマー（Ａ）１００重量部に対して、２０重量部以下であることが好ましく、１０重量部以下であることがさらに好ましい。 In the adhesive composition, the amount of the antistatic agent can be adjusted as appropriate according to the desired surface resistance value of the adhesive sheet 1, and is, for example, 0.05 to 20 parts by weight per 100 parts by weight of the (meth)acrylic polymer (A). From the viewpoint of improving the antistatic performance of the adhesive sheet 1, the amount of the antistatic agent is preferably 0.05 parts by weight or more per 100 parts by weight of the (meth)acrylic polymer (A), more preferably 0.1 parts by weight or more, and even more preferably 0.5 parts by weight or more. From the viewpoint of the durability of the adhesive sheet 1, the amount of the antistatic agent is preferably 20 parts by weight or less per 100 parts by weight of the (meth)acrylic polymer (A), and even more preferably 10 parts by weight or less.
（架橋剤）
　粘着剤組成物は、架橋剤をさらに含んでいてもよい。架橋剤としては、有機系架橋剤、多官能性金属キレートなどを用いることができる。有機系架橋剤としては、例えば、イソシアネート系架橋剤、過酸化物系架橋剤、エポキシ系架橋剤、イミン系架橋剤などが挙げられる。多官能性金属キレートは、多価金属原子が有機化合物と共有結合又は配位結合しているものである。多価金属原子としては、Ａｌ、Ｃｒ、Ｚｒ、Ｃｏ、Ｃｕ、Ｆｅ、Ｎｉ、Ｖ、Ｚｎ、Ｉｎ、Ｃａ、Ｍｇ、Ｍｎ、Ｙ、Ｃｅ、Ｓｒ、Ｂａ、Ｍｏ、Ｌａ、Ｓｎ、Ｔｉなどが挙げられる。共有結合又は配位結合する有機化合物は、例えば酸素原子などを含み、好ましくはアルキルエステル、アルコール化合物、カルボン酸化合物、エーテル化合物、ケトン化合物などが挙げられる。架橋剤は、単独で又は組み合わせて使用できる。 (Crosslinking Agent)
The adhesive composition may further contain a crosslinking agent. As the crosslinking agent, an organic crosslinking agent, a polyfunctional metal chelate, etc. can be used. As the organic crosslinking agent, for example, an isocyanate crosslinking agent, a peroxide crosslinking agent, an epoxy crosslinking agent, an imine crosslinking agent, etc. can be mentioned. In the polyfunctional metal chelate, a polyvalent metal atom is covalently bonded or coordinately bonded to an organic compound. As the polyvalent metal atom, Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, etc. can be mentioned. The organic compound that is covalently bonded or coordinately bonded contains, for example, an oxygen atom, etc., and preferably includes an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, a ketone compound, etc. The crosslinking agent can be used alone or in combination.
　架橋剤としては、イソシアネート系架橋剤及び／又は過酸化物系架橋剤が好ましい。 As the crosslinking agent, an isocyanate-based crosslinking agent and/or a peroxide-based crosslinking agent is preferred.
　イソシアネート系架橋剤としては、少なくとも２個のイソシアネート基を有する化合物（イソシアネート化合物）を用いることができる。イソシアネート化合物に含まれるイソシアネート基の数は、３以上であることが好ましい。イソシアネート基の数の上限は、特に限定されず、例えば５である。イソシアネート化合物の例は、芳香族イソシアネート化合物、脂環族イソシアネート化合物、及び脂肪族イソシアネート化合物である。イソシアネート系架橋剤は、水との反応によって自己重合できる化合物が好ましい。 As the isocyanate-based crosslinking agent, a compound having at least two isocyanate groups (isocyanate compound) can be used. The number of isocyanate groups contained in the isocyanate compound is preferably 3 or more. The upper limit of the number of isocyanate groups is not particularly limited, and is, for example, 5. Examples of isocyanate compounds are aromatic isocyanate compounds, alicyclic isocyanate compounds, and aliphatic isocyanate compounds. As the isocyanate-based crosslinking agent, a compound that can self-polymerize by reacting with water is preferable.
　芳香族イソシアネート化合物の例は、フェニレンジイソシアネート、２，４－トリレンジイソシアネート、２，６－トリレンジイソシアネート、２，２’－ジフェニルメタンジイソシアネート、４，４’－ジフェニルメタンジイソシアネート、４，４’－トルイジンジイソシアネート、４，４’－ジフェニルエーテルジイソシアネート、４，４’－ジフェニルジイソシアネート、１，５－ナフタレンジイソシアネート、及びキシリレンジイソシアネートである。 Examples of aromatic isocyanate compounds are phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenylether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate.
　脂環族イソシアネート化合物の例は、１，３－シクロペンテンジイソシアネート、１，３－シクロヘキサンジイソシアネート、１，４－シクロヘキサンジイソシアネート、イソホロンジイソシアネート、水素添加ジフェニルメタンジイソシアネート、水素添加キシリレンジイソシアネート、水素添加トリレンジイソシアネート、及び水素添加テトラメチルキシリレンジイソシアネートである。 Examples of alicyclic isocyanate compounds are 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated tetramethylxylylene diisocyanate.
　脂肪族イソシアネート化合物の例は、トリメチレンジイソシアネート、テトラメチレンジイソシアネート、ヘキサメチレンジイソシアネート、ペンタメチレンジイソシアネート、１，２－プロピレンジイソシアネート、１，３－ブチレンジイソシアネート、ドデカメチレンジイソシアネート、及び２，４，４－トリメチルヘキサメチレンジイソシアネートである。 Examples of aliphatic isocyanate compounds are trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.
　イソシアネート系架橋剤は、上記イソシアネート化合物の多量体（２量体、３量体、５量体等）、トリメチロールプロパン等の多価アルコールに付加して得られた付加物、ウレア変性体、ビウレット変性体、アロファネート変性体、イソシアヌレート変性体、カルボジイミド変性体、ポリエーテルポリオール、ポリエステルポリオール、アクリルポリオール、ポリブタジエンポリオール、ポリイソプレンポリオール等に付加して得られたウレタンプレポリマーであってもよい。 The isocyanate-based crosslinking agent may be a polymer (dimer, trimer, pentamer, etc.) of the above isocyanate compounds, an adduct obtained by adding the compound to a polyhydric alcohol such as trimethylolpropane, a urea-modified compound, a biuret-modified compound, an allophanate-modified compound, an isocyanurate-modified compound, a carbodiimide-modified compound, or a urethane prepolymer obtained by adding the compound to a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol, etc.
　イソシアネート系架橋剤は、好ましくは芳香族イソシアネート化合物及びその誘導体であり、より好ましくは、トリレンジイソシアネート及びその誘導体、換言すれば、トリレンジイソシアネート系（ＴＤＩ系）架橋剤である。反応性の観点からは、ＴＤＩ系架橋剤が、キシリレンジイソシアネート及びその誘導体、換言すれば、キシリレンジイソシアネート系（ＸＤＩ系）架橋剤に比べて適している。イソシアネート系架橋剤は、ＴＤＩ系架橋剤として、多価アルコール及びトリレンジイソシアネートの付加物を含んでいてもよい。付加物の具体例は、トリメチロールプロパン／トリレンジイソシアネート３量体付加物である。 The isocyanate-based crosslinking agent is preferably an aromatic isocyanate compound and its derivatives, more preferably tolylene diisocyanate and its derivatives, in other words, a tolylene diisocyanate-based (TDI-based) crosslinking agent. From the viewpoint of reactivity, the TDI-based crosslinking agent is more suitable than xylylene diisocyanate and its derivatives, in other words, a xylylene diisocyanate-based (XDI-based) crosslinking agent. The isocyanate-based crosslinking agent may contain an adduct of a polyhydric alcohol and tolylene diisocyanate as a TDI-based crosslinking agent. A specific example of the adduct is a trimethylolpropane/tolylene diisocyanate trimer adduct.
　イソシアネート系架橋剤には市販品を使用できる。市販品の例は、ミリオネートＭＴ、ミリオネートＭＴＬ、ミリオネートＭＲ－２００、ミリオネートＭＲ－４００、コロネートＬ、コロネートＨＬ、コロネートＨＸ（以上、東ソー社製）、タケネートＤ－１０１Ｅ、タケネートＤ－１１０Ｎ、タケネートＤ－１２０Ｎ、タケネートＤ－１４０Ｎ、タケネートＤ－１６０Ｎ、タケネートＤ－１６５Ｎ、タケネートＤ－１７０ＨＮ、タケネートＤ－１７８Ｎ、タケネート５００、タケネート６００（以上、三井化学社製）である。これらの中では、タケネートＤ－１０１Ｅが好ましい。 　Commercially available products can be used as isocyanate-based crosslinking agents. Examples of commercially available products include Millionate MT, Millionate MTL, Millionate MR-200, Millionate MR-400, Coronate L, Coronate HL, Coronate HX (all manufactured by Tosoh Corporation), Takenate D-101E, Takenate D-110N, Takenate D-120N, Takenate D-140N, Takenate D-160N, Takenate D-165N, Takenate D-170HN, Takenate D-178N, Takenate 500, Takenate 600 (all manufactured by Mitsui Chemicals, Inc.). Of these, Takenate D-101E is preferred.
　イソシアネート系架橋剤は、単独で又は２種以上を組み合わせて使用してもよい。 Isocyanate-based crosslinking agents may be used alone or in combination of two or more types.
　過酸化物としては、加熱又は光照射によりラジカル活性種を発生して粘着剤組成物の（メタ）アクリル系ポリマー（Ａ）の架橋を進行させるものであれば適宜使用可能であるが、作業性や安定性を勘案して、１分間半減期温度が８０℃～１６０℃である過酸化物を使用することが好ましく、９０℃～１４０℃である過酸化物を使用することがより好ましい。 Any peroxide can be used as long as it generates radical active species when heated or irradiated with light and promotes crosslinking of the (meth)acrylic polymer (A) of the adhesive composition. Taking into consideration workability and stability, it is preferable to use a peroxide with a 1-minute half-life temperature of 80°C to 160°C, and more preferably a peroxide with a 1-minute half-life temperature of 90°C to 140°C.
　過酸化物としては、例えば、ジ（２－エチルヘキシル）パーオキシジカーボネート（１分間半減期温度：９０．６℃）、ジ（４－ｔ－ブチルシクロヘキシル）パーオキシジカーボネート（１分間半減期温度：９２．１℃）、ジ－ｓｅｃ－ブチルパーオキシジカーボネート（１分間半減期温度：９２．４℃）、ｔ－ブチルパーオキシネオデカノエート（１分間半減期温度：１０３．５℃）、ｔ－ヘキシルパーオキシピバレート（１分間半減期温度：１０９．１℃）、ｔ－ブチルパーオキシピバレート（１分間半減期温度：１１０．３℃）、ジラウロイルパーオキシド（１分間半減期温度：１１６．４℃）、ジ－ｎ－オクタノイルパーオキシド（１分間半減期温度：１１７．４℃）、１，１，３，３－テトラメチルブチルパーオキシ－２－エチルヘキサノエート（１分間半減期温度：１２４．３℃）、ジ（４－メチルベンゾイル）パーオキシド（１分間半減期温度：１２８．２℃）、ジベンゾイルパーオキシド（１分間半減期温度：１３０．０℃）、ｔ－ブチルパーオキシイソブチレート（１分間半減期温度：１３６．１℃）、１，１－ジ（ｔ－ヘキシルパーオキシ）シクロヘキサン（１分間半減期温度：１４９．２℃）などが挙げられる。なかでも特に架橋反応効率が優れることから、ジ（４－ｔ－ブチルシクロヘキシル）パーオキシジカーボネート（１分間半減期温度：９２．１℃）、ジラウロイルパーオキシド（１分間半減期温度：１１６．４℃）、ジベンゾイルパーオキシド（１分間半減期温度：１３０．０℃）などが挙げられる。 Peroxides include, for example, di(2-ethylhexyl) peroxydicarbonate (1-minute half-life temperature: 90.6°C), di(4-t-butylcyclohexyl) peroxydicarbonate (1-minute half-life temperature: 92.1°C), di-sec-butyl peroxydicarbonate (1-minute half-life temperature: 92.4°C), t-butyl peroxyneodecanoate (1-minute half-life temperature: 103.5°C), t-hexyl peroxypivalate (1-minute half-life temperature: 109.1°C), t-butyl peroxypivalate (1-minute half-life temperature: 110.3°C), dilauroyl peroxide ( 1-minute half-life temperature: 116.4°C), di-n-octanoyl peroxide (1-minute half-life temperature: 117.4°C), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (1-minute half-life temperature: 124.3°C), di(4-methylbenzoyl)peroxide (1-minute half-life temperature: 128.2°C), dibenzoyl peroxide (1-minute half-life temperature: 130.0°C), t-butylperoxyisobutyrate (1-minute half-life temperature: 136.1°C), 1,1-di(t-hexylperoxy)cyclohexane (1-minute half-life temperature: 149.2°C), and the like. Among these, di(4-t-butylcyclohexyl) peroxydicarbonate (1-minute half-life temperature: 92.1°C), dilauroyl peroxide (1-minute half-life temperature: 116.4°C), dibenzoyl peroxide (1-minute half-life temperature: 130.0°C), etc. are particularly preferred because of their excellent crosslinking reaction efficiency.
　粘着剤組成物に架橋剤を配合する場合、架橋剤の配合量は、(メタ)アクリル系ポリマー（Ａ）１００重量部に対して、例えば３重量部以下であり、０．０１～３重量部が好ましく、０．０２～２重量部がより好ましく、０．０３～１重量部がさらに好ましい。架橋剤の配合量が０．０１重量部以上である場合、粘着シート１が十分に架橋され、耐久性や粘着特性が向上する傾向がある。一方、架橋剤の配合量が３重量部以下である場合、粘着シート１が硬くなりすぎて耐久性が低下することを抑制できる傾向がある。 When a crosslinking agent is blended into the adhesive composition, the amount of crosslinking agent blended is, for example, 3 parts by weight or less, preferably 0.01 to 3 parts by weight, more preferably 0.02 to 2 parts by weight, and even more preferably 0.03 to 1 part by weight, relative to 100 parts by weight of the (meth)acrylic polymer (A). When the amount of crosslinking agent blended is 0.01 part by weight or more, the adhesive sheet 1 is sufficiently crosslinked, and there is a tendency for the durability and adhesive properties to be improved. On the other hand, when the amount of crosslinking agent blended is 3 parts by weight or less, there is a tendency for the adhesive sheet 1 to be prevented from becoming too hard and reducing its durability.
（シランカップリング剤）
　粘着剤組成物は、シランカップリング剤をさらに含んでいてもよい。シランカップリング剤によれば、粘着シート１の耐久性を向上できる傾向がある。シランカップリング剤の具体例としては、例えば、３－グリシドキシプロピルトリメトキシシラン、３－グリシドキシプロピルトリエトキシシラン、３－グリシドキシプロピルメチルジエトキシシラン、２－（３，４－エポキシシクロヘキシル）エチルトリメトキシシランなどのエポキシ基含有シランカップリング剤；３－アミノプロピルトリメトキシシラン、Ｎ－２－（アミノエチル）－３－アミノプロピルメチルジメトキシシラン、３－トリエトキシシリル－Ｎ－（１，３－ジメチルブチリデン）プロピルアミン、Ｎ－フェニル－γ－アミノプロピルトリメトキシシランなどのアミノ基含有シランカップリング剤；３－アクリロキシプロピルトリメトキシシラン、３－メタクリロキシプロピルトリエトキシシランなどの（メタ）アクリル基含有シランカップリング剤；３－イソシアネートプロピルトリエトキシシランなどのイソシアネート基含有シランカップリング剤などが挙げられ、エポキシ基含有シランカップリング剤が好ましい。 (Silane coupling agent)
The pressure-sensitive adhesive composition may further contain a silane coupling agent. The use of a silane coupling agent tends to improve the durability of the pressure-sensitive adhesive sheet 1. 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-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. Epoxy group-containing silane coupling agents are preferred.
　シランカップリング剤は、分子内に複数のアルコキシシリル基を有していてもよい。このようなシランカップリング剤の具体例としては、例えば、信越化学社製のＸ－４１－１０５３、Ｘ－４１－１０５９Ａ、Ｘ－４１－１０５６、Ｘ－４１－１８０５、Ｘ－４１－１８１８、Ｘ－４１－１８１０、Ｘ－４０－２６５１などが挙げられる。これらのシランカップリング剤は、揮発しにくいだけでなく、粘着シート１の耐久性を効果的に向上できる傾向がある。特に、ガラスと比べて、アルコキシシリル基との反応性が低い透明導電層（例えば、ＩＴＯ層）を被着体として用いる場合であっても、粘着シート１の耐久性が向上しやすい。分子内に複数のアルコキシシリル基を有するシランカップリング剤は、分子内にエポキシ基を有することが好ましく、複数のエポキシ基を有することがさらに好ましい。分子内に複数のアルコキシシリル基を有し、かつエポキシ基を有するシランカップリング剤によれば、透明導電層を被着体として用いる場合であっても、粘着シート１の耐久性がより向上しやすい。このようなシランカップリング剤の具体例としては、信越化学社製のＸ－４１－１０５３、Ｘ－４１－１０５９Ａ、Ｘ－４１－１０５６が挙げられ、特に、エポキシ基を多く含むＸ－４１－１０５６が好ましい。 The silane coupling agent may have multiple alkoxysilyl groups in the molecule. Specific examples of such silane coupling agents include X-41-1053, X-41-1059A, X-41-1056, X-41-1805, X-41-1818, X-41-1810, and X-40-2651 manufactured by Shin-Etsu Chemical Co., Ltd. These silane coupling agents are not only less likely to volatilize, but also tend to effectively improve the durability of the adhesive sheet 1. In particular, the durability of the adhesive sheet 1 is likely to be improved even when a transparent conductive layer (e.g., an ITO layer) that has a lower reactivity with alkoxysilyl groups compared to glass is used as the adherend. The silane coupling agent having multiple alkoxysilyl groups in the molecule preferably has an epoxy group in the molecule, and more preferably has multiple epoxy groups. According to a silane coupling agent having multiple alkoxysilyl groups and an epoxy group in the molecule, the durability of the adhesive sheet 1 is more likely to be improved even when a transparent conductive layer is used as the adherend. Specific examples of such silane coupling agents include X-41-1053, X-41-1059A, and X-41-1056 manufactured by Shin-Etsu Chemical Co., Ltd., and X-41-1056, which contains a large amount of epoxy groups, is particularly preferred.
　シランカップリング剤は、単独で使用してもよく、２種以上を混合して使用してもよい。シランカップリング剤の配合量は、粘着シート１の耐久性を向上させる観点から、（メタ）アクリル系ポリマー（Ａ）１００重量部に対して、例えば５重量部以下であり、０．００１～５重量部、０．０１～１重量部、０．０２～１重量部、さらには０．０５～０．６重量部であることが好ましい。 The silane coupling agent may be used alone or in a mixture of two or more kinds. From the viewpoint of improving the durability of the adhesive sheet 1, the amount of the silane coupling agent is, for example, 5 parts by weight or less relative to 100 parts by weight of the (meth)acrylic polymer (A), and is preferably 0.001 to 5 parts by weight, 0.01 to 1 part by weight, 0.02 to 1 part by weight, or even 0.05 to 0.6 parts by weight.
（添加剤）
　粘着剤組成物は、上述した以外の添加剤をさらに含んでいてもよい。添加剤としては、例えば、反応性シリル基を有するポリエーテル化合物、ポリアルキレングリコール（例えばポリプロピレングリコール）などのポリエーテル化合物、着色剤、顔料等の粉体、染料、界面活性剤、可塑剤、粘着性付与剤、表面潤滑剤、レベリング剤、軟化剤、酸化防止剤、老化防止剤、光安定剤、紫外線吸収剤、重合禁止剤、無機又は有機の充填剤、金属粉、粒子状、箔状物、溶剤等が挙げられる。さらに、制御できる範囲内で、還元剤を加えたレドックス系を採用してもよい。粘着剤組成物において、これらの添加剤の配合量は、（メタ）アクリル系ポリマー（Ａ）１００重量部に対して、例えば５重量部以下であり、３重量部以下、さらには１重量部以下であってもよい。 (Additive)
The adhesive composition may further contain additives other than those mentioned above. Examples of additives include polyether compounds having reactive silyl groups, polyalkylene glycols (e.g., polypropylene glycols), colorants, powders such as pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antiaging agents, light stabilizers, UV absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particles, foils, solvents, etc. Furthermore, within a controllable range, a redox system containing a reducing agent may be used. In the adhesive composition, the amount of these additives may be, for example, 5 parts by weight or less, 3 parts by weight or less, or even 1 part by weight or less, relative to 100 parts by weight of the (meth)acrylic polymer (A).
（粘着シートの物性）
　粘着シート１の厚さは、特に制限されず、例えば、１～１００μｍ程度であり、好ましくは２～５０μｍ、より好ましくは２～４０μｍであり、さらに好ましくは５～３５μｍである。粘着シート１の厚さは、導通構造との接触面積を十分に確保する観点から、５～１００μｍであってもよく、５～５０μｍ、さらには１０～３５μｍであってもよい。 (Physical properties of adhesive sheet)
The thickness of the pressure-sensitive adhesive sheet 1 is not particularly limited and is, for example, about 1 to 100 μm, preferably 2 to 50 μm, more preferably 2 to 40 μm, and even more preferably 5 to 35 μm. From the viewpoint of ensuring a sufficient contact area with the conductive structure, the thickness of the pressure-sensitive adhesive sheet 1 may be 5 to 100 μm, 5 to 50 μm, or even 10 to 35 μm.
　粘着シート１の２５℃における貯蔵弾性率Ｇ’は、特に限定されず、例えば１．０×１０3Ｐａ以上であり、１．０×１０4Ｐａ以上、３．０×１０4Ｐａ以上、５．０×１０4Ｐａ以上、７．０×１０4Ｐａ以上、９．０×１０4Ｐａ以上、さらには１．０×１０5Ｐａ以上であってもよい。粘着シート１の２５℃における貯蔵弾性率Ｇ’の上限は、特に限定されず、例えば１．０×１０7Ｐａ以下である。貯蔵弾性率Ｇ’が高い粘着シート１は、上記の試験１での光学積層体１０の寸法変化量を低下させることに適している。 The storage modulus G' of the pressure-sensitive adhesive sheet 1 at 25°C is not particularly limited, and may be, for example, 1.0 x 103 Pa or more, 1.0 x 104 Pa or more, 3.0 x 104 Pa or more, 5.0 x 104 Pa or more, 7.0 x 104 Pa or more, 9.0 x 104 Pa or more, or even 1.0 x 105 Pa or more. The upper limit of the storage modulus G' of the pressure-sensitive adhesive sheet 1 at 25°C is not particularly limited, and is, for example, 1.0 x 107 Pa or less. A pressure-sensitive adhesive sheet 1 having a high storage modulus G' is suitable for reducing the dimensional change of the optical laminate 10 in the above test 1.
　粘着シート１の２５℃における貯蔵弾性率Ｇ’は、以下の方法によって特定できる。まず、粘着シート１を構成する材料でできた測定用サンプルを準備する。測定用サンプルの形状は、円盤状である。測定用サンプルは、底面の直径が８ｍｍであり、厚さが１ｍｍである。測定用サンプルは、複数の粘着シート１が積層された積層体を円盤状に打ち抜いたものであってもよい。次に、測定用サンプルについて動的粘弾性測定を行う。動的粘弾性測定には、例えば、TA Instruments社製「ARES-G2」を用いることができる。動的粘弾性測定の結果から、粘着シート１の２５℃における貯蔵弾性率Ｇ’を特定することができる。なお、動的粘弾性測定の条件は、以下のとおりである。
・測定条件
　周波数：１Ｈｚ
　変形モード：ねじり
　測定温度：－７０℃～１５０℃
　昇温速度：５℃／分 The storage modulus G' of the adhesive sheet 1 at 25°C can be determined by the following method. First, a measurement sample made of the material constituting the adhesive sheet 1 is prepared. The shape of the measurement sample is disk-shaped. The measurement sample has a bottom diameter of 8 mm and a thickness of 1 mm. The measurement sample may be a disk-shaped punched out laminate in which a plurality of adhesive sheets 1 are laminated. Next, dynamic viscoelasticity measurement is performed on the measurement sample. For example, "ARES-G2" manufactured by TA Instruments can be used for the dynamic viscoelasticity measurement. The storage modulus G' of the adhesive sheet 1 at 25°C can be determined from the results of the dynamic viscoelasticity measurement. The conditions for the dynamic viscoelasticity measurement are as follows.
Measurement conditions Frequency: 1Hz
Deformation mode: Torsion Measurement temperature: -70℃ to 150℃
Heating rate: 5° C./min
　粘着シート１の表面抵抗値は、例えば１．０×１０7Ω／□～１．０×１０12Ω／□であり、１．０×１０8Ω／□～１．０×１０11Ω／□であることが好ましい。粘着シート１の表面抵抗値は、ＪＩＳ　Ｋ６９１１：１９９５に規定された方法に準拠して測定することができる。 The surface resistance of the pressure-sensitive adhesive sheet 1 is, for example, 1.0×10 7 Ω/□ to 1.0×10 12 Ω/□, and preferably 1.0×10 8 Ω/□ to 1.0×10 11 Ω/□. The surface resistance of the pressure-sensitive adhesive sheet 1 can be measured in accordance with the method specified in JIS K6911:1995.
［偏光フィルム］
　偏光フィルム２は、例えば、偏光子及び保護フィルム（透明保護フィルム）を含む。保護フィルムは、例えば、偏光子の主面（最も広い面積を有する表面）に接して配置されている。一例として、偏光フィルム２が２つの保護フィルムを有しており、２つの保護フィルムの間に偏光子が配置されていてもよい。２つの保護フィルムの間に偏光子が配置されている場合、高温多湿環境下での偏光子の色抜けが抑制される傾向がある。 [Polarizing film]
The polarizing film 2 includes, for example, a polarizer and a protective film (transparent protective film). The protective film is arranged, for example, in contact with the main surface (the surface having the widest area) of the polarizer. As an example, the polarizing film 2 may have two protective films, and the polarizer may be arranged between the two protective films. When the polarizer is arranged between the two protective films, discoloration of the polarizer in a high-temperature and high-humidity environment tends to be suppressed.
　偏光子としては、特に限定されず、例えば、ポリビニルアルコール系フィルム、部分ホルマール化ポリビニルアルコール系フィルム、エチレン・酢酸ビニル共重合体系部分ケン化フィルム等の親水性高分子フィルムに、ヨウ素、二色性染料等の二色性物質を吸着させて一軸延伸したもの；ポリビニルアルコールの脱水処理物、ポリ塩化ビニルの脱塩酸処理物等のポリエン系配向フィルム等が挙げられる。偏光子は、典型的には、ポリビニルアルコール系フィルム（ポリビニルアルコール系フィルムには、エチレン・酢酸ビニル共重合体系部分ケン化フィルムが含まれる）、及び、ヨウ素からなる。 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 have been uniaxially stretched after adsorbing dichroic substances such as iodine and dichroic dyes; and polyene-based oriented films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride. Polarizers are typically made of polyvinyl alcohol films (polyvinyl alcohol films include partially saponified ethylene-vinyl acetate copolymer films) and iodine.
　偏光子がヨウ素を含む場合、偏光子におけるヨウ素の含有率は、耐熱性の観点から、例えば６．０重量％以下であり、５．０重量％以下、さらには４．０重量％以下であってもよい。ヨウ素の含有率は、光学特性の観点から、例えば１．０重量％以上であり、１．５重量％以上、さらには２．０重量％以上であってもよい。ヨウ素の含有率が６．０重量％以下である偏光子は、高温多湿環境下での寸法変化が抑制される傾向がある。 When the polarizer contains iodine, the iodine content in the polarizer may be, for example, 6.0% by weight or less, 5.0% by weight or less, or even 4.0% by weight or less, from the viewpoint of heat resistance. The iodine content may be, for example, 1.0% by weight or more, 1.5% by weight or more, or even 2.0% by weight or more, from the viewpoint of optical properties. A polarizer with an iodine content of 6.0% by weight or less tends to suppress dimensional changes in a high-temperature and high-humidity environment.
　偏光子の厚さは、一般的には８０μｍ以下であり、５０μｍ以下、３０μｍ以下、２５μｍ以下、２２μｍ以下、さらには２０μｍ以下であってもよい。偏光子の厚さが小さい場合、上記の試験１での光学積層体１０の寸法変化量が低下する傾向がある。偏光子の厚さの下限は、特に限定されず、例えば１μｍ以上であり、５μｍ以上、６μｍ以上、１０μｍ以上、さらには１５μｍ以上であってもよい。 The thickness of the polarizer is generally 80 μm or less, and may be 50 μm or less, 30 μm or less, 25 μm or less, 22 μm or less, or even 20 μm or less. If the thickness of the polarizer is small, the amount of dimensional change of the optical laminate 10 in the above test 1 tends to decrease. The lower limit of the polarizer thickness is not particularly limited, and may be, for example, 1 μm or more, 5 μm or more, 6 μm or more, 10 μm or more, or even 15 μm or more.
　保護フィルムの材料としては、例えば、透明性、機械的強度、熱安定性、水分遮断性、等方性等に優れる熱可塑性樹脂が用いられる。このような熱可塑性樹脂の具体例としては、トリアセチルセルロース等のセルロース樹脂、ポリエステル樹脂、ポリエーテルスルホン樹脂、ポリスルホン樹脂、ポリカーボネート樹脂、ポリアミド樹脂、ポリイミド樹脂、ポリオレフィン樹脂、（メタ）アクリル樹脂、環状ポリオレフィン樹脂（ノルボルネン系樹脂）、ポリアリレート樹脂、ポリスチレン樹脂、ポリビニルアルコール樹脂、及び、これらの混合物が挙げられる。保護フィルムの材料は、（メタ）アクリル系、ウレタン系、アクリルウレタン系、エポキシ系、シリコーン系等の熱硬化性樹脂又は紫外線硬化型樹脂であってもよい。偏光フィルム２が２つの保護フィルムを有する場合、２つの保護フィルムの材料は、互いに同じであってもよく、異なっていてもよい。例えば、偏光子の一方の主面に対して、接着剤を介して、熱可塑性樹脂で構成された保護フィルムが貼り合わされ、偏光子の他方の主面に対して、熱硬化性樹脂又は紫外線硬化型樹脂で構成された保護フィルムが貼り合わされていてもよい。保護フィルムは、任意の添加剤を１種類以上含んでいてもよい。添加剤としては、例えば、紫外線吸収剤、酸化防止剤、滑剤、可塑剤、離型剤、着色防止剤、難燃剤、核剤、帯電防止剤、顔料、着色剤等が挙げられる。 As the material of the protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture blocking property, isotropy, etc. is used. 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 resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The material of the protective film may be a thermosetting resin or an ultraviolet-curing resin such as a (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone. When the polarizing film 2 has two protective films, the materials of the two protective films may be the same or different from each other. For example, a protective film made of a thermoplastic resin may be attached to one main surface of the polarizer via an adhesive, and a protective film made of a thermosetting resin or an ultraviolet-curing resin may be attached to the other main surface of the polarizer. The protective film may contain one or more types of optional additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, color inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.
　保護フィルムの材料は、粘着シート１の表面抵抗値の変動を抑制する観点から、セルロース樹脂、（メタ）アクリル樹脂などが好ましい。（メタ）アクリル樹脂としては、ラクトン環構造を有する（メタ）アクリル系樹脂が好ましい。ラクトン環構造を有する（メタ）アクリル系樹脂としては、特開２０００－２３００１６号公報、特開２００１－１５１８１４号公報、特開２００２－１２０３２６号公報、特開２００２－２５４５４４号公報、特開２００５－１４６０８４号公報などに記載されている。セルロース樹脂は、（メタ）アクリル樹脂に比べて、偏光子のクラックを効果的に抑制できる傾向がある。 From the viewpoint of suppressing fluctuations in the surface resistance value of the adhesive sheet 1, the material of the protective film is preferably a cellulose resin, a (meth)acrylic resin, or the like. As the (meth)acrylic resin, a (meth)acrylic resin having a lactone ring structure is preferable. Examples of (meth)acrylic resins having a lactone ring structure are described in JP-A Nos. 2000-230016, 2001-151814, 2002-120326, 2002-254544, and 2005-146084. Compared to (meth)acrylic resins, cellulose resins tend to be able to suppress cracks in the polarizer more effectively.
　保護フィルムの厚さは、適宜に決定しうるが、一般には強度や取扱性等の作業性、薄膜性等の点より１０～２００μｍ程度である。 The thickness of the protective film can be determined as appropriate, but is generally around 10 to 200 μm, taking into consideration strength, ease of handling, thinness, etc.
　偏光子と保護フィルムとは、接着シート、粘着シート、下塗り層（プライマー層）などの介在層を介して積層される。介在層により、偏光子と保護フィルムとを隙間なく積層することが好ましい。介在層は、接着シートであることが好ましい。接着シートを形成する接着剤は、光学的に透明であれば特に制限されず、水系、溶剤系、ホットメルト系、ラジカル硬化型、カチオン硬化型の各種形態の接着剤が挙げられ、水系接着剤又はラジカル硬化型接着剤が好ましい。 The polarizer and protective film are laminated via an intervening layer such as an adhesive sheet, a pressure sensitive adhesive sheet, or an undercoat layer (primer layer). It is preferable that the polarizer and protective film are laminated without gaps by the intervening layer. The intervening layer is preferably an adhesive sheet. There are no particular limitations on the adhesive that forms the adhesive sheet as long as it is optically transparent, and examples of the adhesive that can be used include various types of adhesives such as water-based, solvent-based, hot melt, radical curing, and cationic curing, with water-based adhesives or radical curing adhesives being preferred.
　偏光フィルム２は、保護フィルムに代えて、位相差フィルム、拡散フィルムなどを有していてもよい。位相差フィルムとしては、正面位相差が４０ｎｍ以上であり、及び／又は、厚み方向位相差が８０ｎｍ以上であるものが挙げられる。位相差フィルムでは、通常、正面位相差が４０～２００ｎｍの範囲で調整され、厚み方向位相差が８０～３００ｎｍの範囲で調整される。位相差フィルムは、保護フィルムとしても機能するため、偏光フィルム２が位相差フィルムを含む場合、偏光フィルム２の薄型化を図ることができる。 The polarizing film 2 may have a retardation film, a diffusion film, etc., instead of a protective film. Examples of retardation films include those having a front retardation of 40 nm or more and/or a thickness direction retardation of 80 nm or more. In retardation films, the front retardation is usually adjusted to a range of 40 to 200 nm, and the thickness direction retardation is adjusted to a range of 80 to 300 nm. Since the retardation film also functions as a protective film, when the polarizing film 2 includes a retardation film, the polarizing film 2 can be made thinner.
［光学積層体の製造方法］
　光学積層体１０は、例えば、次の方法によって製造できる。まず、上述した粘着剤組成物をはく離ライナーの上に塗布し、乾燥させることによって粘着シート１を形成する。粘着シート１を偏光フィルム２に転写することによって光学積層体１０を作製することができる。なお、粘着剤組成物を偏光フィルム２の上に塗布し、乾燥させて粘着シート１を形成することによっても光学積層体１０を作製できる。 [Method of manufacturing optical laminate]
The optical laminate 10 can be produced, for example, by the following method. First, the above-mentioned pressure-sensitive adhesive composition is applied onto a release liner and dried to form a pressure-sensitive adhesive sheet 1. The pressure-sensitive adhesive sheet 1 is transferred to a polarizing film 2 to produce the optical laminate 10. Note that the optical laminate 10 can also be produced by applying the pressure-sensitive adhesive composition onto a polarizing film 2 and drying to form the pressure-sensitive adhesive sheet 1.
［導電性ペースト］
　上述のとおり、本実施形態において、導電性ペーストは、光学積層体１０の側面１０ｃのうち、試験１により求めた寸法変化量が８０μｍ以下となる部分に塗布されて導通構造を形成するものである。さらに、導電性ペーストは、試験２により求めた破断伸度が５％以上である。これらの要件を満たす限り、導電性ペーストは、特に限定されない。 [Conductive paste]
As described above, in this embodiment, the conductive paste is applied to a portion of the side surface 10c of the optical laminate 10 where the dimensional change amount determined by Test 1 is 80 μm or less to form a conductive structure. Furthermore, the conductive paste has a breaking elongation of 5% or more determined by Test 2. As long as these requirements are met, the conductive paste is not particularly limited.
　導電性ペーストは、例えば、金属及びバインダーを含む。詳細には、導電性ペーストは、金属粒子を含み、当該金属粒子がバインダー中に分散している。導電性ペーストにおいて、金属は、導電成分として機能する。金属としては、銅、銀、白金、金、アルミニウム、ニッケル、亜鉛、リチウム、マグネシウム、コバルトなどが挙げられる。導電性ペーストにおいて、金属は、銀を含むことが好ましい。 The conductive paste contains, for example, a metal and a binder. In detail, the conductive paste contains metal particles, and the metal particles are dispersed in the binder. In the conductive paste, the metal functions as a conductive component. Examples of the metal include copper, silver, platinum, gold, aluminum, nickel, zinc, lithium, magnesium, and cobalt. In the conductive paste, it is preferable that the metal contains silver.
　導電性ペーストにおける金属の含有率は、導電性の観点から、例えば４０重量％以上であり、５０重量％以上、さらには５５重量％以上であってもよい。金属の含有率の上限は、特に限定されず、例えば７０重量％以下である。 From the viewpoint of electrical conductivity, the metal content in the conductive paste is, for example, 40% by weight or more, and may be 50% by weight or more, or even 55% by weight or more. There is no particular upper limit to the metal content, and it is, for example, 70% by weight or less.
　バインダーは、例えば、熱硬化型樹脂を含む。熱硬化型樹脂としては、例えば、ポリエステル樹脂、シリコーン樹脂、ポリウレタン樹脂などが挙げられる。これらの樹脂は、試験２により求められる破断伸度を増加させることに適している。バインダーは、熱硬化型樹脂として、ポリエステル樹脂及びシリコーン樹脂からなる群より選ばれる少なくとも１つを含むことが好ましい。 The binder includes, for example, a thermosetting resin. Examples of thermosetting resins include polyester resin, silicone resin, and polyurethane resin. These resins are suitable for increasing the breaking elongation determined by Test 2. It is preferable that the binder includes, as the thermosetting resin, at least one selected from the group consisting of polyester resin and silicone resin.
　導電性ペーストにおけるバインダーの含有率は、導通構造の耐久性の観点から、例えば３０重量％以上であり、４０重量％以上、さらには５０重量％以上であってもよい。バインダーの含有率の上限は、特に限定されず、例えば６０重量％以下である。 The binder content in the conductive paste may be, for example, 30% by weight or more, 40% by weight or more, or even 50% by weight or more, from the viewpoint of durability of the conductive structure. The upper limit of the binder content is not particularly limited, and is, for example, 60% by weight or less.
　なお、バインダーが熱硬化型樹脂としてエポキシ樹脂を含む場合、試験２により求めた破断伸度が低下する傾向がある。そのため、バインダーにおいて、エポキシ樹脂の含有率は低いことが好ましく、例えば１重量％以下であり、０．１重量％以下である。バインダーは、エポキシ樹脂を実質的に含まないことが好ましい。 If the binder contains an epoxy resin as a thermosetting resin, the breaking elongation determined by Test 2 tends to decrease. Therefore, it is preferable that the content of epoxy resin in the binder is low, for example, 1% by weight or less, and 0.1% by weight or less. It is preferable that the binder does not substantially contain epoxy resin.
　導電性ペーストは、光学積層体１０の側面１０ｃ（詳細には、粘着シート１の側面や偏光フィルム２の側面）との密着力が高いことが好ましい。一例として、導電性ペーストは、下記試験３により求めた密着力が０．１Ｎ／２５ｍｍ以上であることが好ましい。
　試験３：無アルカリガラスに導電性ペーストを塗布し、平膜を作製する。粘着シート１を介して、光学積層体１０を平膜の表面に貼り付ける。剥離角度９０°、剥離速度３００ｍｍ／ｍｉｎで、光学積層体１０を平膜から引きはがす。このときに必要な力（密着力）を測定する。 The conductive paste preferably has high adhesion to the side surface 10c of the optical laminate 10 (specifically, the side surface of the pressure-sensitive adhesive sheet 1 or the side surface of the polarizing film 2). As an example, the conductive paste preferably has an adhesion strength of 0.1 N/25 mm or more as determined by the following Test 3.
Test 3: A conductive paste is applied to non-alkali glass to prepare a flat film. The optical laminate 10 is attached to the surface of the flat film via the adhesive sheet 1. The optical laminate 10 is peeled off from the flat film at a peel angle of 90° and a peel speed of 300 mm/min. The force (adhesion force) required at this time is measured.
　試験３は、詳細には、次の方法によって行う。まず、厚さ０．５ｍｍの無アルカリガラス（例えば、コーニング社製、１７３７）を準備する。無アルカリガラスに導電性ペーストを塗布し、例えば、６０℃～１５０℃の環境下で、１５分～５時間加熱処理することによって硬化させ、平膜を作製する。次に、粘着シート１を介して、光学積層体１０（幅２５ｍｍ）を平膜の表面に貼り付ける。光学積層体１０の貼り付けは、例えば、ラミネーターを用いて行う。次に、５０℃、５ａｔｍで１５分間オートクレーブ処理することにより、光学積層体１０を平膜に密着させる。 In detail, Test 3 is carried out by the following method. First, a non-alkali glass (e.g., Corning 1737) with a thickness of 0.5 mm is prepared. A conductive paste is applied to the non-alkali glass, and cured by heat treatment for 15 minutes to 5 hours in an environment of, for example, 60°C to 150°C to produce a flat film. Next, the optical laminate 10 (width 25 mm) is attached to the surface of the flat film via the adhesive sheet 1. The optical laminate 10 is attached, for example, using a laminator. Next, the optical laminate 10 is adhered to the flat film by autoclaving for 15 minutes at 50°C and 5 atm.
　次に、引張試験機（例えば、オートグラフＳＨＩＭＡＺＵ　ＡＧ－１　１０ＫＮ）を用いて、剥離角度９０°、剥離速度３００ｍｍ／ｍｉｎで、光学積層体１０を平膜から引きはがす（測定長８０ｍｍ）。このとき、光学積層体１０を無アルカリガラスから引きはがすために必要な力を１回／０．５ｓの間隔で測定する。得られた測定値の平均値を密着力（Ｎ／２５ｍｍ）として特定する。 Next, using a tensile tester (e.g., Autograph Shimazu AG-1 10KN), the optical laminate 10 is peeled off from the flat film at a peel angle of 90° and a peel speed of 300 mm/min (measurement length 80 mm). At this time, the force required to peel the optical laminate 10 off the alkali-free glass is measured once every 0.5 s. The average value of the obtained measurements is specified as the adhesion strength (N/25 mm).
　上記の密着力は、１Ｎ／２５ｍｍ以上であってもよく、５Ｎ／２５ｍｍ以上であってもよい。密着力の上限は、特に限定されず、例えば２０Ｎ／２５ｍｍ以下である。 The adhesion strength may be 1 N/25 mm or more, or 5 N/25 mm or more. The upper limit of the adhesion strength is not particularly limited, and is, for example, 20 N/25 mm or less.
　上述のとおり、導電性ペーストは、光学積層体１０の側面１０ｃのうち、試験１により求めた寸法変化量が８０μｍ以下となる部分に塗布されて導通構造を形成する。導通構造を形成するときには、必要に応じて、上記の部分に塗布された導電性ペーストを硬化させてもよい。導電性ペーストは、例えば、６０℃～１５０℃の環境下で、１５分～５時間加熱処理することによって硬化させることができる。 As described above, the conductive paste is applied to the portion of the side surface 10c of the optical laminate 10 where the dimensional change determined by Test 1 is 80 μm or less to form a conductive structure. When forming the conductive structure, the conductive paste applied to the above portion may be cured as necessary. The conductive paste can be cured, for example, by heat treatment in an environment of 60°C to 150°C for 15 minutes to 5 hours.
＜画像表示パネルの実施形態＞
　本実施形態の画像表示パネルの一例を図３Ａに示す。図３Ａの画像表示パネル１００Ａは、画像表示セル３０Ａ、上述した光学積層体１０、及び導通構造２０を備えている。導通構造２０は、上述した導電性ペーストから形成されており、光学積層体１０の側面１０ｃのうち、試験１により求めた寸法変化量が８０μｍ以下となる部分に接触している。上述のとおり、導電性ペーストは、試験２により求めた破断伸度が５％以上である。本実施形態の画像表示パネル１００Ａを備えた画像表示装置は、高温多湿環境を経た場合であっても、導通構造２０と光学積層体１０との間で破断が生じにくく、これにより、帯電防止性能が低下しにくい傾向がある。 <Embodiments of Image Display Panel>
An example of the image display panel of this embodiment is shown in FIG. 3A. The image display panel 100A of FIG. 3A includes an image display cell 30A, the optical laminate 10 described above, and a conductive structure 20. The conductive structure 20 is formed from the conductive paste described above, and is in contact with a portion of the side surface 10c of the optical laminate 10 where the dimensional change amount determined by Test 1 is 80 μm or less. As described above, the conductive paste has a breaking elongation determined by Test 2 of 5% or more. An image display device including the image display panel 100A of this embodiment is less likely to break between the conductive structure 20 and the optical laminate 10 even when it is subjected to a high temperature and high humidity environment, and therefore tends to be less likely to have a reduced antistatic performance.
［光学積層体］
　画像表示パネル１００Ａにおいて、光学積層体１０は、例えば、画像表示セル３０Ａよりも視認側に配置されている。光学積層体１０は、例えば、粘着シート１を介して、画像表示セル３０Ａに貼り合わされている。 [Optical laminate]
In the image display panel 100A, the optical laminate 10 is disposed, for example, on the viewing side of the image display cell 30A. The optical laminate 10 is attached to the image display cell 30A via, for example, an adhesive sheet 1.
［導通構造］
　上述のとおり、導通構造２０は、光学積層体１０の側面１０ｃのうち、試験１により求めた寸法変化量が８０μｍ以下となる部分に接触している。導通構造２０は、上記の寸法変化量が８０μｍ以下となる部分の全体と接触していてもよく、当該部分の一部と接触していてもよい。導通構造２０は、上記の寸法変化量が８０μｍよりも大きい部分と接触していないことが好ましい。 [Conductive structure]
As described above, the conductive structure 20 is in contact with the portion of the side surface 10c of the optical laminate 10 where the dimensional change determined by Test 1 is 80 μm or less. The conductive structure 20 may be in contact with the entire portion where the dimensional change is 80 μm or less, or may be in contact with a part of the portion. It is preferable that the conductive structure 20 is not in contact with the portion where the dimensional change is greater than 80 μm.
　導通構造２０は、光学積層体１０の側面１０ｃのうち、少なくとも粘着シート１の側面に接触していることが好ましく、典型的には、粘着シート１の側面及び偏光フィルム２の側面の両方に接触している。導通構造２０の一部は、光学積層体１０の主面１０ａ（詳細には、偏光フィルム２の主面）に接触していてもよい。導通構造２０は、例えば、光学積層体１０の厚さ方向に延びており、その一端が画像表示セル３０Ａに接している。 The conductive structure 20 is preferably in contact with at least the side surface of the adhesive sheet 1 among the side surfaces 10c of the optical laminate 10, and typically is in contact with both the side surface of the adhesive sheet 1 and the side surface of the polarizing film 2. A part of the conductive structure 20 may be in contact with the main surface 10a of the optical laminate 10 (specifically, the main surface of the polarizing film 2). The conductive structure 20 extends, for example, in the thickness direction of the optical laminate 10, and one end thereof is in contact with the image display cell 30A.
　光学積層体１０の側面１０ｃ全体の面積に対する、導通構造２０によって覆われた光学積層体１０の側面１０ｃの面積の比率は、例えば１％以上であり、好ましくは３％以上である。この比率は、９９％以下であってもよく、９５％以下であってもよい。 The ratio of the area of the side 10c of the optical laminate 10 covered by the conductive structure 20 to the total area of the side 10c of the optical laminate 10 is, for example, 1% or more, and preferably 3% or more. This ratio may be 99% or less, or 95% or less.
　導通構造２０は、光学積層体１０の側面１０ｃと接触することによって、画像表示パネル１００Ａの帯電を抑制することができる。導通構造２０は、アース電極などに接続されていることが好ましい。 The conductive structure 20 can suppress charging of the image display panel 100A by contacting the side surface 10c of the optical laminate 10. It is preferable that the conductive structure 20 is connected to an earth electrode or the like.
［画像表示セル］
　画像表示セル３０Ａは、例えば、画像形成層３２、第１透明基板３１及び第２透明基板３３を備えている。画像形成層３２は、例えば、第１透明基板３１及び第２透明基板３３の間に配置されており、第１透明基板３１及び第２透明基板３３のそれぞれに接している。光学積層体１０の粘着シート１は、例えば、画像表示セル３０Ａの第１透明基板３１に接している。粘着シート１と第１透明基板３１の間には、導電層が配置されていないことが好ましい。 [Image display cell]
The image display cell 30A includes, for example, an image forming layer 32, a first transparent substrate 31, and a second transparent substrate 33. The image forming layer 32 is, for example, disposed between the first transparent substrate 31 and the second transparent substrate 33, and is in contact with each of the first transparent substrate 31 and the second transparent substrate 33. The adhesive sheet 1 of the optical laminate 10 is, for example, in contact with the first transparent substrate 31 of the image display cell 30A. It is preferable that no conductive layer is disposed between the adhesive sheet 1 and the first transparent substrate 31.
　画像形成層３２は、例えば、電界が存在しない状態でホモジニアス配向した液晶分子を含む液晶層である。このような液晶分子を含む液晶層は、ＩＰＳ（In-Plane-Switching）方式に適している。ただし、液晶層は、ＴＮ（Twisted Nematic）型、ＳＴＮ（Super Twisted Nematic）型、π型、ＶＡ（Vertical Alignment）型等に用いられてもよい。本明細書では、液晶層を備えた画像表示セルを液晶セルと呼び、液晶セルを備えた画像表示パネルを液晶パネルと呼ぶことがある。なお、画像形成層３２は、ＥＬ発光層であってもよい。 The image forming layer 32 is, for example, a liquid crystal layer containing liquid crystal molecules that are homogeneously oriented in the absence of an electric field. A liquid crystal layer containing such liquid crystal molecules is suitable for the IPS (In-Plane-Switching) method. However, the liquid crystal layer may also be used in TN (Twisted Nematic) type, STN (Super Twisted Nematic) type, π type, VA (Vertical Alignment) type, etc. In this specification, an image display cell having a liquid crystal layer may be called a liquid crystal cell, and an image display panel having a liquid crystal cell may be called a liquid crystal panel. The image forming layer 32 may be an EL light-emitting layer.
　画像形成層３２の厚さは、例えば、１．５μｍ～４μｍである。 The thickness of the image forming layer 32 is, for example, 1.5 μm to 4 μm.
　第１透明基板３１及び第２透明基板３３の材料としては、例えば、ガラス及びポリマーが挙げられる。本明細書では、ポリマーで構成された透明基板をポリマーフィルムと呼ぶことがある。透明基板を構成するポリマーとしては、例えば、ポリエチレンテレフタレート、ポリシクロオレフィン、ポリカーボネート等が挙げられる。ガラスで構成された透明基板の厚さは、例えば、０．１ｍｍ～１ｍｍである。ポリマーで構成された透明基板の厚さは、例えば、１０μｍ～２００μｍである。 Examples of materials for the first transparent substrate 31 and the second transparent substrate 33 include glass and polymer. In this specification, a transparent substrate made of a polymer may be referred to as a polymer film. Examples of polymers that make up a transparent substrate include polyethylene terephthalate, polycycloolefin, and polycarbonate. The thickness of a transparent substrate made of glass is, for example, 0.1 mm to 1 mm. The thickness of a transparent substrate made of a polymer is, for example, 10 μm to 200 μm.
　画像表示セル３０Ａは、画像形成層３２、第１透明基板３１及び第２透明基板３３以外の他の層をさらに含んでいてもよい。他の層としては、例えば、カラーフィルタ、易接着層及びハードコート層が挙げられる。カラーフィルタは、例えば、画像形成層３２よりも視認側に配置されており、好ましくは第１透明基板３１と光学積層体１０の粘着シート１との間に位置する。易接着層及びハードコート層は、例えば、第１透明基板３１又は第２透明基板３３の表面上に配置されている。 The image display cell 30A may further include layers other than the image forming layer 32, the first transparent substrate 31, and the second transparent substrate 33. Examples of the other layers include a color filter, an easy-adhesion layer, and a hard coat layer. The color filter is, for example, disposed on the viewing side of the image forming layer 32, and is preferably located between the first transparent substrate 31 and the adhesive sheet 1 of the optical laminate 10. The easy-adhesion layer and the hard coat layer are, for example, disposed on the surface of the first transparent substrate 31 or the second transparent substrate 33.
［他の部材］
　画像表示パネル１００Ａは、光学積層体１０、導通構造２０及び画像表示セル３０Ａ以外の他の部材をさらに備えていてもよい。一例として、画像表示パネル１００Ａは、他の部材として、追加の粘着シート５、及び追加の偏光フィルム６をさらに備えていてもよい。粘着シート５及び偏光フィルム６は、画像表示セル３０Ａに対して光学積層体１０とは反対側に位置する。粘着シート５は、例えば、画像表示セル３０Ａの第２透明基板３３と接しており、粘着シート５を介して、偏光フィルム６が画像表示セル３０Ａに貼り合わされている。偏光フィルム６は、例えば、その吸収軸が、偏光フィルム２の吸収軸と直交するように配置される。 [Other components]
The image display panel 100A may further include other members other than the optical laminate 10, the conductive structure 20, and the image display cell 30A. As an example, the image display panel 100A may further include an additional adhesive sheet 5 and an additional polarizing film 6 as other members. The adhesive sheet 5 and the polarizing film 6 are located on the opposite side of the image display cell 30A from the optical laminate 10. The adhesive sheet 5 is in contact with, for example, the second transparent substrate 33 of the image display cell 30A, and the polarizing film 6 is bonded to the image display cell 30A via the adhesive sheet 5. The polarizing film 6 is arranged, for example, so that its absorption axis is perpendicular to the absorption axis of the polarizing film 2.
　偏光フィルム６は、偏光フィルム２について上述したものを用いることができる。偏光フィルム６は、偏光フィルム２と同じであってもよく、異なっていてもよい。 The polarizing film 6 can be the same as or different from the polarizing film 2.
　粘着シート５は、例えば、粘着剤組成物から形成される。この粘着剤組成物としては、粘着シート１について上述したものが挙げられる。粘着シート５を形成する粘着剤組成物は、粘着シート１を形成する粘着剤組成物と同じであってもよく、異なっていてもよい。粘着シート５の厚さは、特に限定されず、例えば、１～１００μｍ程度であり、好ましくは２～５０μｍ、より好ましくは２～４０μｍであり、さらに好ましくは５～３５μｍである。 The adhesive sheet 5 is formed, for example, from an adhesive composition. Examples of this adhesive composition include those described above for the adhesive sheet 1. The adhesive composition forming the adhesive sheet 5 may be the same as the adhesive composition forming the adhesive sheet 1, or may be different. The thickness of the adhesive sheet 5 is not particularly limited, and is, for example, about 1 to 100 μm, preferably 2 to 50 μm, more preferably 2 to 40 μm, and even more preferably 5 to 35 μm.
　画像表示パネル１００Ａは、他の部材として、反射フィルム、反透過フィルム、位相差フィルム（λ／２板やλ／４板）、視野角補償フィルム、輝度向上フィルム等の画像表示装置に用いられる光学フィルムをさらに備えていてもよい。画像表示パネル１００Ａは、これらの１種又は２種以上の光学フィルムを備えていてもよい。 The image display panel 100A may further include, as other components, optical films used in image display devices, such as a reflective film, an anti-transmitting film, a retardation film (a λ/2 plate or a λ/4 plate), a viewing angle compensation film, and a brightness enhancement film. The image display panel 100A may include one or more of these optical films.
　本実施形態の画像表示パネルは、タッチセンシング機能を内蔵する画像表示パネルであってもよい。タッチセンシング機能を内蔵する画像表示パネルの例を図３Ｂ～３Ｆに示す。図３Ｂ～３Ｆの画像表示パネル１００Ｂ～１００Ｆは、タッチセンシング電極部を含む画像表示セル３０Ｂ～３０Ｆを備えている。これらの画像表示セルにおいて、タッチセンシング電極部は、第１透明基板３１と第２透明基板３３との間に配置されている。タッチセンシング電極部は、タッチセンサ及びタッチ駆動の機能を有する。 The image display panel of this embodiment may be an image display panel with a built-in touch sensing function. Examples of image display panels with a built-in touch sensing function are shown in Figures 3B to 3F. The image display panels 100B to 100F of Figures 3B to 3F include image display cells 30B to 30F that include a touch sensing electrode portion. In these image display cells, the touch sensing electrode portion is disposed between the first transparent substrate 31 and the second transparent substrate 33. The touch sensing electrode portion has the functions of a touch sensor and touch drive.
　画像表示パネル１００Ｂ～１００Ｆは、いわゆるインセル型画像表示パネルであり、画像表示セル３０Ｂ～３０Ｆは、いわゆるインセル型画像表示セルである。ただし、画像表示セルにおいて、タッチセンシング電極部は、第１透明基板３１よりも視認側に配置されていてもよい。すなわち、本実施形態の画像表示パネルは、いわゆるオンセル型画像表示パネルであってもよく、画像表示セルは、いわゆるオンセル型画像表示セルであってもよい。 The image display panels 100B to 100F are so-called in-cell type image display panels, and the image display cells 30B to 30F are so-called in-cell type image display cells. However, in the image display cells, the touch sensing electrode portion may be disposed on the viewing side of the first transparent substrate 31. In other words, the image display panel of this embodiment may be a so-called on-cell type image display panel, and the image display cells may be so-called on-cell type image display cells.
　図３Ｂ、３Ｃ及び３Ｆに示すように、タッチセンシング電極部３５は、例えば、タッチセンサ電極３６及びタッチ駆動電極３７を有する。タッチセンサ電極３６とは、タッチ検出用の（受信）電極を意味する。タッチセンサ電極３６及びタッチ駆動電極３７は、それぞれ独立して各種パターンにより形成することができる。例えば、画像表示セル３０Ｂが平板状である場合、タッチセンサ電極３６及びタッチ駆動電極３７をそれぞれＸ軸方向及びＹ軸方向に独立して設け、これらが直角に交差するようなパターンに形成することができる。図３Ｂ、３Ｃ及び３Ｆでは、タッチセンシング電極部３５において、タッチセンサ電極３６がタッチ駆動電極３７よりも視認側に配置されている。ただし、タッチ駆動電極３７がタッチセンサ電極３６よりも視認側に配置されていてもよい。 As shown in Figs. 3B, 3C, and 3F, the touch sensing electrode unit 35 has, for example, a touch sensor electrode 36 and a touch drive electrode 37. The touch sensor electrode 36 means a (receiving) electrode for touch detection. The touch sensor electrode 36 and the touch drive electrode 37 can be formed independently in various patterns. For example, when the image display cell 30B is flat, the touch sensor electrode 36 and the touch drive electrode 37 can be provided independently in the X-axis direction and the Y-axis direction, respectively, and formed in a pattern in which they intersect at right angles. In Figs. 3B, 3C, and 3F, in the touch sensing electrode unit 35, the touch sensor electrode 36 is disposed on the viewing side of the touch drive electrode 37. However, the touch drive electrode 37 may be disposed on the viewing side of the touch sensor electrode 36.
　タッチセンシング電極部３５において、タッチセンサ電極３６及びタッチ駆動電極３７は、一体化されていてもよい。一例として、図３Ｄ及び３Ｅに示す画像表示セル３０Ｄ及び３０Ｅは、タッチセンサ電極及びタッチ駆動電極が一体化された電極３８を有している。 In the touch sensing electrode portion 35, the touch sensor electrode 36 and the touch drive electrode 37 may be integrated. As an example, the image display cells 30D and 30E shown in Figures 3D and 3E have an electrode 38 in which the touch sensor electrode and the touch drive electrode are integrated.
　図３Ｂ及び３Ｄにおいて、タッチセンシング電極部３５又は電極３８は、画像形成層３２と第１透明基板３１との間（画像形成層３２よりも視認側）に配置されている。ただし、図３Ｃ及び３Ｅに示すように、タッチセンシング電極部３５又は電極３８は、画像形成層３２と第２透明基板３３との間（画像形成層３２よりも照明システム側）に配置されていてもよい。 In Figures 3B and 3D, the touch sensing electrode unit 35 or electrode 38 is disposed between the image forming layer 32 and the first transparent substrate 31 (on the viewing side of the image forming layer 32). However, as shown in Figures 3C and 3E, the touch sensing electrode unit 35 or electrode 38 may be disposed between the image forming layer 32 and the second transparent substrate 33 (on the lighting system side of the image forming layer 32).
　タッチセンシング電極部３５において、タッチセンサ電極３６及びタッチ駆動電極３７は、互いに接していなくてもよい。例えば、図３Ｆに示す画像表示セル３０Ｅでは、タッチセンサ電極３６が画像形成層３２と第１透明基板３１との間に配置され、タッチ駆動電極３７が画像形成層３２と第２透明基板３３との間に配置されている。 In the touch sensing electrode section 35, the touch sensor electrode 36 and the touch drive electrode 37 do not need to be in contact with each other. For example, in the image display cell 30E shown in FIG. 3F, the touch sensor electrode 36 is disposed between the image forming layer 32 and the first transparent substrate 31, and the touch drive electrode 37 is disposed between the image forming layer 32 and the second transparent substrate 33.
　タッチセンシング電極部における駆動電極（タッチ駆動電極３７、又は、タッチセンサ電極とタッチ駆動電極とが一体化された電極３８）は、画像形成層３２を制御する共通電極を兼ねることができる。 The drive electrode in the touch sensing electrode section (touch drive electrode 37, or electrode 38 in which the touch sensor electrode and the touch drive electrode are integrated) can also serve as a common electrode that controls the image forming layer 32.
　タッチセンシング電極部３５を構成するタッチセンサ電極３６（静電容量センサー）、タッチ駆動電極３７、又は、これらを一体化して形成した電極３８は、透明導電層として機能する。この透明導電層の材料は、特に限定されず、例えば、金、銀、銅、白金、パラジウム、アルミニウム、ニッケル、クロム、チタン、鉄、コバルト、錫、マグネシウム、タングステン等の金属、及び、これらの合金等が挙げられる。透明導電層の材料は、インジウム、スズ、亜鉛、ガリウム、アンチモン、ジルコニウム、カドミウムなどの金属の酸化物であってもよい。この酸化物としては、具体的には、酸化インジウム、酸化スズ、酸化チタン、酸化カドミウム及びこれらの混合物等が挙げられる。透明導電層の材料は、ヨウ化銅等の金属化合物であってもよい。透明導電層の材料は、酸化スズを含有する酸化インジウム（ＩＴＯ）、アンチモンを含有する酸化スズ等が好ましく、ＩＴＯが特に好ましい。透明導電層の材料がＩＴＯである場合、透明導電層における酸化インジウムの含有率が８０～９９重量％であり、かつ酸化スズの含有率が１～２０重量％であることが好ましい。 The touch sensor electrode 36 (capacitive sensor), the touch drive electrode 37, or the electrode 38 formed by integrating these electrodes, which constitute the touch sensing electrode unit 35, function as a transparent conductive layer. The material of this transparent conductive layer is not particularly limited, and examples thereof include metals such as gold, silver, copper, platinum, palladium, aluminum, nickel, chromium, titanium, iron, cobalt, tin, magnesium, and tungsten, and alloys thereof. The material of the transparent conductive layer may be an oxide of a metal such as indium, tin, zinc, gallium, antimony, zirconium, or cadmium. Specific examples of this oxide include indium oxide, tin oxide, titanium oxide, cadmium oxide, and mixtures thereof. The material of the transparent conductive layer may be a metal compound such as copper iodide. The material of the transparent conductive layer is preferably indium oxide (ITO) containing tin oxide, tin oxide containing antimony, and the like, and ITO is particularly preferred. When the material of the transparent conductive layer is ITO, it is preferable that the indium oxide content in the transparent conductive layer is 80 to 99% by weight and the tin oxide content is 1 to 20% by weight.
　タッチセンシング電極部３５を構成する電極（タッチセンサ電極３６、タッチ駆動電極３７、又は、これらを一体化して形成した電極３８）は、第１透明基板３１及び／又は第２透明基板３３の内側（画像形成層３２側）において、常法により透明電極パターンとして形成することができる。この透明電極パターンは、例えば、透明基板の端部に形成された引き回し線（図示せず）に電気的に接続されている。引き回し線は、例えば、コントローラＩＣ（図示せず）と接続されている。透明電極パターンの形状としては、櫛状、ストライプ状、ひし形状等、用途に応じて任意の形状を採用することができる。透明電極パターンの厚さは、例えば１０ｎｍ～１００ｎｍである。透明電極パターンの幅は、例えば０．１ｍｍ～５ｍｍである。 The electrodes constituting the touch sensing electrode section 35 (the touch sensor electrode 36, the touch drive electrode 37, or the electrode 38 formed by integrating these) can be formed as a transparent electrode pattern by a conventional method on the inside (image forming layer 32 side) of the first transparent substrate 31 and/or the second transparent substrate 33. This transparent electrode pattern is electrically connected, for example, to a wiring line (not shown) formed at the end of the transparent substrate. The wiring line is connected, for example, to a controller IC (not shown). The transparent electrode pattern can be in any shape depending on the application, such as a comb shape, a stripe shape, or a diamond shape. The thickness of the transparent electrode pattern is, for example, 10 nm to 100 nm. The width of the transparent electrode pattern is, for example, 0.1 mm to 5 mm.
＜画像表示装置の実施形態＞
　本実施形態の画像表示装置は、例えば、上述した画像表示パネル及び照明システムを備えている。画像表示装置において、画像表示パネルは、例えば、照明システムよりも視認側に配置されている。照明システムは、例えば、バックライト又は反射板を有し、画像表示パネルに光を照射する。 <Embodiments of Image Display Device>
The image display device of this embodiment includes, for example, the image display panel and the illumination system described above. In the image display device, the image display panel is disposed, for example, closer to the viewing side than the illumination system. The illumination system includes, for example, a backlight or a reflector, and irradiates light onto the image display panel.
　画像表示装置は、有機ＥＬディスプレイであってもよく、液晶ディスプレイであってもよい。ただし、画像表示装置はこの例に限定されない。画像表示装置は、エレクトロルミネッセンス（ＥＬ）ディスプレイ、プラズマディスプレイ（ＰＤ）、電界放出ディスプレイ（ＦＥＤ：Field Emission Display）などであってもよい。画像表示装置は、家電用途、車載用途、パブリックインフォメーションディスプレイ（ＰＩＤ）用途などに用いることができ、車載用ディスプレイであることが好ましい。 The image display device may be an organic EL display or a liquid crystal display. However, the image display device is not limited to this example. The image display device may be an electroluminescence (EL) display, a plasma display (PD), a field emission display (FED: Field Emission Display), etc. The image display device may be used for home appliance applications, in-vehicle applications, public information display (PID) applications, etc., and is preferably an in-vehicle display.
　以下、実施例により、本発明をさらに詳細に説明する。本発明は、以下に示す実施例に限定されない。なお、各例中の部及び％はいずれも重量基準である。以下に特に規定のない試験条件は全て２３℃６５％ＲＨである。 The present invention will be described in more detail below with reference to the following examples. The present invention is not limited to the following examples. Note that all parts and percentages in each example are by weight. All test conditions below unless otherwise specified are 23°C and 65% RH.
＜（メタ）アクリル系ポリマーの重量平均分子量＞
　以下の実施例において、（メタ）アクリル系ポリマーの重量平均分子量（Ｍｗ）は、ＧＰＣ（ゲル・パーミエーション・クロマトグラフィー）により測定した。（メタ）アクリル系ポリマーのＭｗ／Ｍｎについても、同様に測定した。
・分析装置：東ソー社製、ＨＬＣ－８１２０ＧＰＣ
・カラム：東ソー社製、Ｇ７０００ＨXL＋ＧＭＨXL＋ＧＭＨXL
・カラムサイズ：各７．８ｍｍφ×３０ｃｍ　計９０ｃｍ
・カラム温度：４０℃
・流量：０．８ｍＬ／ｍｉｎ
・注入量：１００μＬ
・溶離液：テトラヒドロフラン
・検出器：示差屈折計（ＲＩ）
・標準試料：ポリスチレン <Weight average molecular weight of (meth)acrylic polymer>
In the following examples, the weight average molecular weight (Mw) of the (meth)acrylic polymer was measured by gel permeation chromatography (GPC). The Mw/Mn of the (meth)acrylic polymer was also measured in the same manner.
Analytical equipment: Tosoh Corporation, HLC-8120GPC
Column: Tosoh Corporation, G7000H XL + GMH XL + GMH XL
Column size: 7.8 mm diameter x 30 cm, total 90 cm
Column temperature: 40°C
Flow rate: 0.8 mL / min
Injection volume: 100 μL
Eluent: Tetrahydrofuran Detector: Differential refractometer (RI)
・Standard sample: polystyrene
＜偏光フィルムＦ１の作製＞
（ＨＣ付４０μｍＴＡＣフィルム）
　ウレタンアクリレートを主成分として含む紫外線硬化型樹脂モノマー又はオリゴマーが酢酸ブチルに溶解された樹脂溶液（ＤＩＣ（株）製、商品名：ユニディック１７－８０６、固形分濃度：８０％）に、その溶液中の固形分１００部当たり、光重合開始剤（ＢＡＳＦ（株）製、商品名：ＩＲＧＡＣＵＲＥ９０７）を５部、及びレベリング剤（ＤＩＣ（株）製、商品名：ＧＲＡＮＤＩＣ　ＰＣ４１００）を０．１部添加した。次に、溶液中の固形分濃度が３６％となるように、溶液にシクロペンタノンとプロピレングリコールモノメチルエーテルを４５：５５の比率で加えて、ハードコート層形成材料を作製した。作製したハードコート層形成材料を、硬化後のハードコート層の厚みが７μｍになるようにＴＪ４０ＵＬ（富士フイルム製、原料：トリアセチルセルロース系ポリマー、厚み：４０μｍ）上に塗布して塗膜を形成した。塗膜を９０℃で１分間乾燥し、さらに高圧水銀ランプにて積算光量３００ｍＪ／ｃｍ2の紫外線を塗膜に照射し、塗膜を硬化させてハードコート層（ＨＣ）を形成して、ＨＣ付４０μｍＴＡＣフィルムを作製した。 <Preparation of Polarizing Film F1>
(40μm TAC film with HC)
A resin solution in which an ultraviolet-curable resin monomer or oligomer containing urethane acrylate as a main component is dissolved in butyl acetate (manufactured by DIC Corporation, product name: Unidic 17-806, solid content concentration: 80%) was added with 5 parts of a photopolymerization initiator (manufactured by BASF Corporation, product name: IRGACURE 907) and 0.1 parts of a leveling agent (manufactured by DIC Corporation, product name: GRANDIC PC4100) per 100 parts of solid content in the solution. Next, cyclopentanone and propylene glycol monomethyl ether were added to the solution in a ratio of 45:55 so that the solid content concentration in the solution was 36%, to prepare a hard coat layer forming material. The prepared hard coat layer forming material was applied onto TJ40UL (manufactured by Fujifilm Corporation, raw material: triacetyl cellulose polymer, thickness: 40 μm) so that the thickness of the hard coat layer after curing was 7 μm to form a coating film. The coating film was dried at 90° C. for 1 minute, and then irradiated with ultraviolet light from a high-pressure mercury lamp at an integrated light intensity of 300 mJ/cm 2 to harden the coating film and form a hard coat layer (HC), thereby producing a 40 μm TAC film with HC.
（３０μｍアクリルフィルム）
　攪拌装置、温度センサー、冷却管、窒素導入管を備えた容量３０Ｌの釜型反応器に、８，０００ｇのメタクリル酸メチル（ＭＭＡ）、２，０００ｇの２－（ヒドロキシメチル）アクリル酸メチル（ＭＨＭＡ）、１０，０００ｇの４－メチル－２－ペンタノン（メチルイソブチルケトン、ＭＩＢＫ）、５ｇのｎ－ドデシルメルカプタンを仕込み、これに窒素を通じつつ、１０５℃まで昇温し、還流したところで、重合開始剤として５．０ｇのｔ－ブチルパーオキシイソプロピルカーボネート（カヤカルボンＢＩＣ－７、化薬アクゾ（株）製）を添加すると同時に、１０．０ｇのｔ－ブチルパーオキシイソプロピルカーボネートと２３０ｇのＭＩＢＫからなる溶液を４時間かけて滴下しながら、還流下、約１０５～１２０℃で溶液重合を行い、さらに４時間かけて熟成を行った。 (30 μm acrylic film)
A 30 L kettle reactor equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen inlet tube was charged with 8,000 g of methyl methacrylate (MMA), 2,000 g of methyl 2-(hydroxymethyl)acrylate (MHMA), 10,000 g of 4-methyl-2-pentanone (methyl isobutyl ketone, MIBK), and 5 g of n-dodecyl mercaptan. The mixture was heated to 105° C. while passing nitrogen through it, and when it was refluxed, 5.0 g of t-butylperoxyisopropyl carbonate (Kayacarvon BIC-7, manufactured by Kayaku Akzo Co., Ltd.) was added as a polymerization initiator. At the same time, a solution consisting of 10.0 g of t-butylperoxyisopropyl carbonate and 230 g of MIBK was added dropwise over 4 hours, while solution polymerization was carried out under reflux at about 105 to 120° C., and the mixture was further aged over 4 hours.
　得られた重合体溶液に、３０ｇのリン酸ステアリル／リン酸ジステアリル混合物（ＰｈｏｓｌｅｘＡ－１８、堺化学工業（株）製）を加え、還流下、約９０～１２０℃で５時間、環化縮合反応を行った。次いで、得られた重合体溶液を、バレル温度２６０℃、回転数１００ｒｐｍ、減圧度１３．３～４００ｈＰａ（１０～３００ｍｍＨｇ）、リアベント数１個、フォアベント数４個のベントタイプスクリュー二軸押出し機（φ＝２９．７５ｍｍ、Ｌ／Ｄ＝３０）に、樹脂量換算で、２．０ｋｇ／ｈの処理速度で導入し、この押出し機内で、さらに環化縮合反応と脱揮を行い、押し出すことにより、ラクトン環含有重合体の透明なペレットを得た。 30 g of a stearyl phosphate/distearyl phosphate mixture (Phoslex A-18, Sakai Chemical Industry Co., Ltd.) was added to the resulting polymer solution, and a cyclization condensation reaction was carried out under reflux at approximately 90 to 120°C for 5 hours. The resulting polymer solution was then introduced into a vent-type twin-screw extruder (φ=29.75 mm, L/D=30) with a barrel temperature of 260°C, a rotation speed of 100 rpm, a vacuum degree of 13.3 to 400 hPa (10 to 300 mmHg), one rear vent, and four fore vents at a processing rate of 2.0 kg/h in terms of resin amount, and further cyclization condensation reaction and devolatilization were carried out in this extruder, and transparent pellets of lactone ring-containing polymer were obtained by extrusion.
　得られたラクトン環含有重合体について、ダイナミックＴＧの測定を行ったところ、０．１７質量％の質量減少を検知した。また、このラクトン環含有重合体は、重量平均分子量が１３３，０００、メルトフローレートが６．５ｇ／１０ｍｉｎ、ガラス転移温度が１３１℃であった。 When the obtained lactone ring-containing polymer was subjected to dynamic TG measurement, a mass loss of 0.17% was detected. In addition, this lactone ring-containing polymer had a weight average molecular weight of 133,000, a melt flow rate of 6.5 g/10 min, and a glass transition temperature of 131°C.
　得られたペレットと、アクリロニトリル－スチレン（ＡＳ）樹脂（トーヨーＡＳＡＳ２０、東洋スチレン（株）製）とを、質量比９０／１０で、単軸押出機（スクリュー３０ｍｍφ）を用いて混練押出することにより、透明なペレットを得た。得られたペレットのガラス転移温度は１２７℃であった。 The pellets obtained were mixed and extruded in a mass ratio of 90/10 with acrylonitrile-styrene (AS) resin (Toyo ASAS20, manufactured by Toyo Styrene Co., Ltd.) using a single-screw extruder (screw diameter 30 mm) to obtain transparent pellets. The glass transition temperature of the pellets obtained was 127°C.
　このペレットを、５０ｍｍφ単軸押出機を用い、４００ｍｍ幅のコートハンガータイプＴダイから溶融押出し、厚さ１２０μｍのフィルムを作製した。作製したフィルムを、２軸延伸装置を用いて、１５０℃の温度条件下、縦２．０倍、及び横２．０倍に延伸することにより、厚さ３０μｍの延伸フィルム（３０μｍアクリルフィルム）を得た。この延伸フィルムの光学特性を測定したところ、全光線透過率が９３％、面内位相差Δｎｄが０．８ｎｍ、厚み方向位相差Ｒｔｈが１．５ｎｍであった。 The pellets were melt-extruded from a 400 mm wide coat hanger type T-die using a 50 mmφ single screw extruder to produce a film with a thickness of 120 μm. The film produced was stretched 2.0 times vertically and 2.0 times horizontally at a temperature of 150°C using a biaxial stretching device to obtain a stretched film with a thickness of 30 μm (30 μm acrylic film). The optical properties of this stretched film were measured to find that the total light transmittance was 93%, the in-plane retardation Δnd was 0.8 nm, and the thickness direction retardation Rth was 1.5 nm.
（偏光フィルムＦ１）
　厚さ４５μｍのポリビニルアルコールフィルムを、速度比の異なるロール間において、温度３０℃、濃度０．３％のヨウ素溶液中で１分間染色しながら、３倍まで延伸した。次に、濃度４％でホウ酸を含み、かつ濃度１０％でヨウ化カリウムを含む、温度６０℃の水溶液中に０．５分間浸漬しながら、総合延伸倍率が６倍になるまで延伸した。次に、濃度１．５％でヨウ化カリウムを含む、温度３０℃の水溶液中に１０秒間浸漬させて洗浄した後、５０℃で４分間乾燥を行うことによって、厚さ１８μｍの偏光子を得た。当該偏光子の片面に、けん化処理したＨＣ付４０μｍＴＡＣフィルム（トリアセチルセルロースフィルム側）をポリビニルアルコール系接着剤により貼り合せた。さらに、偏光子の他方の面に、３０μｍアクリルフィルムをポリビニルアルコール系接着剤により貼り合せた。これにより、偏光フィルムＦ１を得た。 (Polarizing film F1)
A 45 μm thick polyvinyl alcohol film was stretched to 3 times between rolls with different speed ratios while dyeing in a 0.3% iodine solution at 30° C. for 1 minute. Next, the film was stretched to 6 times the total stretch ratio while immersing in an aqueous solution at 60° C. containing 4% boric acid and 10% potassium iodide for 0.5 minutes. Next, the film was immersed in an aqueous solution at 30° C. containing 1.5% potassium iodide for 10 seconds for cleaning, and then dried at 50° C. for 4 minutes to obtain a 18 μm thick polarizer. A saponified HC-attached 40 μm TAC film (triacetyl cellulose film side) was bonded to one side of the polarizer with a polyvinyl alcohol-based adhesive. Furthermore, a 30 μm acrylic film was bonded to the other side of the polarizer with a polyvinyl alcohol-based adhesive. This resulted in a polarizing film F1.
＜偏光フィルムＦ２の作製＞
　厚さ８０μｍのポリビニルアルコールフィルムを、速度比の異なるロール間において、温度３０℃、濃度０．３％のヨウ素溶液中で１分間染色しながら、３倍まで延伸した。次に、濃度４％でホウ酸を含み、かつ濃度１０％でヨウ化カリウムを含む、温度６０℃の水溶液中に０．５分間浸漬しながら、総合延伸倍率が６倍になるまで延伸した。次に、濃度１．５％でヨウ化カリウムを含む、温度３０℃の水溶液中に１０秒間浸漬させて洗浄した後、５０℃で４分間乾燥を行うことによって、厚さ２８μｍの偏光子を得た。当該偏光子の片面に、ラクトン環構造を有する変性アクリル系ポリマーからなる厚さ３０μｍの透明保護フィルムをポリビニルアルコール系接着剤により貼り合せた。さらに、偏光子の他方の面に、トリアセチルセルロースフィルム（コニカミノルタ製、商品名「ＫＣ４ＵＹ」）にハードコート層（ＨＣ）を形成した厚さ４７μｍの透明保護フィルムをポリビニルアルコール系接着剤により貼り合せた。７０℃に設定されたオーブン内で５分間加熱乾燥させることによって偏光フィルムＦ２を作製した。 <Preparation of Polarizing Film F2>
A polyvinyl alcohol film having a thickness of 80 μm was stretched to 3 times while being dyed for 1 minute in an iodine solution having a concentration of 0.3% at a temperature of 30° C. between rolls having different speed ratios. Next, the film was stretched to a total stretching ratio of 6 times while being immersed for 0.5 minutes in an aqueous solution having a temperature of 60° C. and containing boric acid at a concentration of 4% and potassium iodide at a concentration of 10%. Next, the film was immersed for 10 seconds in an aqueous solution having a temperature of 30° C. and containing potassium iodide at a concentration of 1.5% to wash, and then dried at 50° C. for 4 minutes to obtain a polarizer having a thickness of 28 μm. A transparent protective film having a thickness of 30 μm and made of a modified acrylic polymer having a lactone ring structure was bonded to one surface of the polarizer with a polyvinyl alcohol adhesive. Furthermore, a transparent protective film having a thickness of 47 μm, which was made of a triacetyl cellulose film (manufactured by Konica Minolta, product name "KC4UY") with a hard coat layer (HC) formed thereon, was bonded to the other surface of the polarizer with a polyvinyl alcohol adhesive. The film was dried by heating in an oven set at 70° C. for 5 minutes to prepare a polarizing film F2.
＜偏光フィルムＦ３の作製＞
（薄型偏光子）
　吸水率０．７５％、Ｔｇ７５℃の非晶質のイソフタル酸共重合ポリエチレンテレフタレート（ＩＰＡ共重合ＰＥＴ）フィルム（厚み：１００μｍ）基材の片面に、コロナ処理を施し、このコロナ処理面に、ポリビニルアルコール（重合度４２００、ケン化度９９．２モル％）及びアセトアセチル変性ポリビニルアルコール（重合度１２００、アセトアセチル変性度４．６％、ケン化度９９．０モル％以上、日本合成化学工業社製、商品名「ゴーセファイマーＺ２００」）を９：１の比で含む水溶液を２５℃で塗布及び乾燥して、厚み１１μｍのポリビニルアルコール系樹脂層を形成し、積層体を作製した。 <Preparation of Polarizing Film F3>
(Thin polarizer)
One side of an amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 100 μm) substrate having a water absorption rate of 0.75% and a Tg of 75° C. was subjected to a corona treatment, and an aqueous solution containing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified polyvinyl alcohol (degree of polymerization 1200, degree of acetoacetyl modification 4.6%, degree of saponification 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name "GOHSEFYMER Z200") in a ratio of 9:1 was applied to the corona-treated surface and dried at 25° C. to form a polyvinyl alcohol-based resin layer having a thickness of 11 μm, and a laminate was produced.
　得られた積層体を、１２０℃のオーブン内で周速の異なるロール間で縦方向（長手方向）に２．０倍に自由端一軸延伸した（空中補助延伸処理）。次に、積層体を、液温３０℃の不溶化浴（水１００重量部に対して、ホウ酸を４重量部配合して得られたホウ酸水溶液）に３０秒間浸漬させた（不溶化処理）。次に、液温３０℃の染色浴（水１００重量部に対して、ヨウ素を０．２重量部配合し、ヨウ化カリウムを１．０重量部配合して得られたヨウ素水溶液）に６０秒間浸漬させた（染色処理）。次に、液温３０℃の架橋浴（水１００重量部に対して、ヨウ化カリウムを３重量部配合し、ホウ酸を３重量部配合して得られたホウ酸水溶液）に３０秒間浸漬させた（架橋処理）。次に、積層体を、液温７０℃のホウ酸水溶液（水１００重量部に対して、ホウ酸を４重量部配合し、ヨウ化カリウムを５重量部配合して得られた水溶液）に浸漬させながら、周速の異なるロール間で縦方向（長手方向）に総延伸倍率が５．５倍となるように一軸延伸を行った（水中延伸処理）。次に、積層体を液温３０℃の洗浄浴（水１００重量部に対して、ヨウ化カリウムを４重量部配合して得られた水溶液）に浸漬させた（洗浄処理）。これにより、厚み５μｍの偏光子を含む光学フィルム積層体を得た。 The obtained laminate was uniaxially stretched at the free end by 2.0 times in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds in an oven at 120°C (air-assisted stretching treatment). Next, the laminate was immersed in an insolubilization bath (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) with a liquid temperature of 30°C for 30 seconds (insolubilization treatment). Next, the laminate was immersed in a dyeing bath (an iodine aqueous solution obtained by blending 0.2 parts by weight of iodine and 1.0 part by weight of potassium iodide with 100 parts by weight of water) with a liquid temperature of 30°C for 60 seconds (dyeing treatment). Next, the laminate was immersed in a crosslinking bath (a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with 100 parts by weight of water) with a liquid temperature of 30°C for 30 seconds (crosslinking treatment). Next, the laminate was immersed in an aqueous solution of boric acid (aqueous solution obtained by blending 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 70°C, and uniaxially stretched between rolls with different peripheral speeds in the longitudinal direction (longitudinal direction) to a total stretch ratio of 5.5 times (underwater stretching treatment). Next, the laminate was immersed in a cleaning bath (aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 30°C (cleaning treatment). As a result, an optical film laminate including a polarizer with a thickness of 5 μm was obtained.
（接着剤）
　アクリロイルモルホリン４５重量部、１，９－ノナンジオールジアクリレート４５部、（メタ）アクリルモノマーを重合してなるアクリル系オリゴマー（ＡＲＵＦＯＮＵＰ１１９０、東亞合成社製）１０部、光重合開始剤（ＩＲＧＡＣＵＲＥ９０７、ＢＡＳＦ社製）３部、重合開始剤（ＫＡＹＡＣＵＲＥ　ＤＥＴＸ－Ｓ、日本化薬社製）１．５部を混合し、紫外線硬化型接着剤を調製した。 (glue)
An ultraviolet-curing adhesive was prepared by mixing 45 parts by weight of acryloylmorpholine, 45 parts of 1,9-nonanediol diacrylate, 10 parts of an acrylic oligomer obtained by polymerizing a (meth)acrylic monomer (ARUFONUP1190, manufactured by Toagosei Co., Ltd.), 3 parts of a photopolymerization initiator (IRGACURE907, manufactured by BASF Corporation), and 1.5 parts of a polymerization initiator (KAYACURE DETX-S, manufactured by Nippon Kayaku Co., Ltd.).
（偏光フィルムＦ３）
　上記光学フィルム積層体の偏光子の表面に、硬化後の接着剤層の厚みが１μｍとなるように上記紫外線硬化型接着剤を塗布し、ＨＣ付２５μｍＴＡＣフィルム（トリアセチルセルロースフィルム側）を貼り合わせた。ＨＣ付２５μｍＴＡＣフィルムは、上述のＨＣ付４０μｍＴＡＣフィルムと同様の方法によって作製した。次に、活性エネルギー線として、紫外線を照射し、接着剤を硬化させた。紫外線照射は、ガリウム封入メタルハライドランプ、照射装置：Ｆｕｓｉｏｎ　ＵＶ　Ｓｙｓｔｅｍｓ，Ｉｎｃ社製のＬｉｇｈｔ　ＨＡＭＭＥＲ１０、バルブ：Ｖバルブ、ピーク照度：１６００ｍＷ／ｃｍ2、積算照射量１０００／ｍＪ／ｃｍ2（波長３８０～４４０ｎｍ）を使用し、紫外線の照度は、Ｓｏｌａｔｅｌｌ社製のＳｏｌａ－Ｃｈｅｃｋシステムを使用して測定した。次に、非晶性ＰＥＴ基材を剥離し、薄型偏光子を用いた偏光フィルムＦ３を作製した。得られた偏光フィルムＦ３の光学特性は、単体透過率４２．８％、偏光度９９．９９％であった。 (Polarizing film F3)
The above ultraviolet-curable adhesive was applied to the surface of the polarizer of the optical film laminate so that the thickness of the adhesive layer after curing was 1 μm, and a 25 μm TAC film with HC (triacetyl cellulose film side) was bonded. The 25 μm TAC film with HC was produced by the same method as the above 40 μm TAC film with HC. Next, ultraviolet rays were irradiated as active energy rays to cure the adhesive. For ultraviolet irradiation, a gallium-encapsulated metal halide lamp, an irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., a bulb: V bulb, a peak illuminance: 1600 mW/cm 2 , and an integrated dose of 1000/mJ/cm 2 (wavelength 380 to 440 nm) were used, and the illuminance of the ultraviolet rays was measured using a Sola-Check system manufactured by Solatell. Next, the amorphous PET substrate was peeled off, and a polarizing film F3 using a thin polarizer was produced. The optical properties of the obtained polarizing film F3 were a single transmittance of 42.8% and a polarization degree of 99.99%.
（実施例１）
［（メタ）アクリル系ポリマーＡ１の調製］
　まず、攪拌羽根、温度計、窒素ガス導入管及び冷却器を備えた４つ口フラスコに、メトキシエチルアクリレート６０重量部、ブチルアクリレート３９重量部、及び４－ヒドロキシブチルアクリレート１重量部を含有する単量体混合物を仕込んだ。さらに、単量体混合物１００重量部に対して、重合開始剤として２，２’－アゾビスイソブチロニトリル（ＡＩＢＮ）０．１重量部を酢酸エチル１００重量部と共に仕込んだ。混合物を緩やかに攪拌しながら、フラスコ内について窒素ガスを導入して窒素置換した。フラスコ内の液温を５５℃付近に維持して８時間重合反応を行うことによって、重量平均分子量（Ｍｗ）１９５万、Ｍｗ／Ｍｎ＝３．９の（メタ）アクリル系ポリマーＡ１の溶液を調製した。 Example 1
[Preparation of (meth)acrylic polymer A1]
First, a monomer mixture containing 60 parts by weight of methoxyethyl acrylate, 39 parts by weight of butyl acrylate, and 1 part by weight of 4-hydroxybutyl acrylate was charged into a four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler. Furthermore, 0.1 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) was charged as a polymerization initiator together with 100 parts by weight of ethyl acetate per 100 parts by weight of the monomer mixture. While gently stirring the mixture, nitrogen gas was introduced into the flask to replace the atmosphere with nitrogen. The liquid temperature in the flask was maintained at about 55°C, and the polymerization reaction was carried out for 8 hours, thereby preparing a solution of (meth)acrylic polymer A1 having a weight average molecular weight (Mw) of 1,950,000 and Mw/Mn = 3.9.
［粘着剤組成物の調製］
　（メタ）アクリル系ポリマーＡ１の溶液の固形分１００重量部に対して、１－エチル－３－メチルイミダゾリウムビス（フルオロスルホニル）イミド（エレクセルＡＳ－１１０、第一工業製薬社製）５重量部、イソシアネート架橋剤（東ソー社製のコロネートＬ、トリメチロールプロパントリレンジイソシアネート）０．６重量部、及びベンゾイルパーオキサイド（日本油脂社製のナイパーＢＭＴ）０．１重量部を配合して、粘着剤組成物を調製した。 [Preparation of Pressure-Sensitive Adhesive Composition]
A pressure-sensitive adhesive composition was prepared by blending 5 parts by weight of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (ELEXEL AS-110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 0.6 parts by weight of an isocyanate crosslinking agent (Coronate L, manufactured by Tosoh Corporation, trimethylolpropane tolylene diisocyanate), and 0.1 parts by weight of benzoyl peroxide (Niper BMT, manufactured by NOF Corporation) with respect to 100 parts by weight of the solid content of the (meth)acrylic polymer A1 solution.
［光学積層体の作製］
　次に、上記の粘着剤組成物を、シリコーン系剥離剤で処理されたポリエチレンテレフタレートフィルム（はく離ライナー：三菱化学ポリエステルフィルム（株）製、ＭＲＦ３８）の片面に、乾燥後の粘着シートの厚さが２０μｍになるように塗布した。得られた塗布膜を１５５℃で１分間乾燥させることによって、はく離ライナーの表面に粘着シートを形成した。次に、はく離ライナー上に形成した粘着シートを上述の偏光フィルムＦ１のアクリルフィルム側に転写して、光学積層体（粘着シート付き偏光フィルム）を作製した。 [Preparation of optical laminate]
Next, the above pressure-sensitive adhesive composition was applied to one side of a polyethylene terephthalate film (release liner: MRF38, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) treated with a silicone-based release agent, so that the thickness of the adhesive sheet after drying was 20 μm. The resulting coating film was dried at 155° C. for 1 minute to form an adhesive sheet on the surface of the release liner. Next, the adhesive sheet formed on the release liner was transferred to the acrylic film side of the above-mentioned polarizing film F1 to produce an optical laminate (polarizing film with adhesive sheet).
［画像表示パネル］
　次に、光学積層体からはく離ライナーを剥がして、インセル型液晶セルの視認側の表面に貼り合わせた。次に、光学積層体の側面のうち、偏光フィルムの吸収軸方向に延びる部分（図２の部分Ｓ１）に導電性ペースト（太陽インキ社製、ＥＬＥＰＡＳＴＥ　ＮＰ－１）を塗布し、硬化させることによって、導通構造を形成した。導電性ペーストは、銀粒子とポリエステル樹脂を含み、導電成分（銀粒子）の含有率が５７重量％であった。導通構造は、粘着シート及び偏光フィルムの各側面と接触していた。導通構造は、外部のアース電極と接続させた。さらに、インセル型液晶セル内部の透明電極パターン周辺部の引き回し配線をコントローラＩＣと接続させた。これにより、タッチセンシング機能を内蔵する実施例１の画像表示パネル（液晶パネル）を作製した。 [Image display panel]
Next, the release liner was peeled off from the optical laminate and attached to the surface of the viewing side of the in-cell type liquid crystal cell. Next, a conductive paste (ELEPASTE NP-1, manufactured by Taiyo Ink Co., Ltd.) was applied to the part (part S1 in FIG. 2) of the side of the optical laminate extending in the absorption axis direction of the polarizing film, and cured to form a conductive structure. The conductive paste contained silver particles and polyester resin, and the content of the conductive component (silver particles) was 57% by weight. The conductive structure was in contact with each side of the adhesive sheet and the polarizing film. The conductive structure was connected to an external earth electrode. Furthermore, the wiring around the transparent electrode pattern inside the in-cell type liquid crystal cell was connected to the controller IC. In this way, an image display panel (liquid crystal panel) of Example 1 with a built-in touch sensing function was produced.
（実施例２～５、比較例１及び２）
　以下の表１～２に示すように、粘着剤組成物の組成、偏光フィルムの種類、導電性ペーストの種類を変更したことを除き、実施例１と同じ方法によって実施例２～５、比較例１及び２の画像表示パネル（液晶パネル）を作製した。なお、実施例２で用いた導電性ペースト（セメダイン社製、ＳＸ－ＥＣＡ４８）は、銀粒子とポリエステル樹脂を含み、導電成分の含有率が７０～８０重量％であった。比較例２で用いた導電性ペースト（ＴｈｒｅｅＢｏｎｄ社製、ＴＢ３３３１Ｄ）は、ニッケル粒子とエポキシ樹脂を含み、導電成分の含有率が４６重量％であった。 (Examples 2 to 5, Comparative Examples 1 and 2)
As shown in Tables 1 and 2 below, image display panels (liquid crystal panels) of Examples 2 to 5 and Comparative Examples 1 and 2 were produced by the same method as Example 1, except that the composition of the adhesive composition, the type of polarizing film, and the type of conductive paste were changed. The conductive paste used in Example 2 (SX-ECA48, manufactured by Cemedine) contained silver particles and polyester resin, and the content of the conductive component was 70 to 80% by weight. The conductive paste used in Comparative Example 2 (TB3331D, manufactured by ThreeBond) contained nickel particles and epoxy resin, and the content of the conductive component was 46% by weight.
＜粘着シートの貯蔵弾性率＞
　実施例及び比較例で作製した粘着シートについて、上述の方法によって動的粘弾性測定を行い、２５℃における貯蔵弾性率Ｇ’を特定した。 <Storage modulus of adhesive sheet>
For the pressure-sensitive adhesive sheets produced in the Examples and Comparative Examples, dynamic viscoelasticity measurement was carried out by the above-mentioned method, and the storage modulus G' at 25°C was determined.
＜光学積層体の寸法変化量＞
　実施例及び比較例で作製した光学積層体について、上述の試験１を行い、偏光フィルムの吸収軸方向に延びる部分（図２の部分Ｓ１）の寸法変化量Ｌ１を特定した。 <Dimensional change of optical laminate>
The optical laminates produced in the examples and comparative examples were subjected to the above-mentioned Test 1, and the amount of dimensional change L1 of the portion extending in the absorption axis direction of the polarizing film (portion S1 in FIG. 2) was determined.
＜導電性ペーストの破断伸度＞
　実施例及び比較例で用いた導電性ペーストについて、上述の試験２を行い、破断伸度を特定した。 <Elongation at break of conductive paste>
The conductive pastes used in the examples and comparative examples were subjected to the above-mentioned Test 2 to determine the breaking elongation.
＜画像表示パネルの耐久性＞
［破断の有無］
　実施例及び比較例の画像表示パネルについて、温度８５℃、湿度８５％ＲＨの条件で２４０時間加熱処理を行った。加熱処理後に、画像表示パネルの表面を走査型電子顕微鏡（ＳＥＭ）で観察し、導通構造と光学積層体との間での破断の有無を確認し、下記基準で評価した。
（評価基準）
　Ａ：導通構造と光学積層体との間で破断が生じていない。
　Ｂ：導通構造と光学積層体との間で一部破断が生じているが、実用上、問題ない範囲にある。
　Ｃ：導通構造と光学積層体との間で破断が生じており、実用上、問題がある。 <Durability of image display panel>
[Presence or absence of breakage]
The image display panels of the examples and comparative examples were subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH. After the heat treatment, the surface of the image display panel was observed with a scanning electron microscope (SEM) to check for the presence or absence of breakage between the conductive structure and the optical laminate, and evaluated according to the following criteria.
(Evaluation criteria)
A: No break occurs between the conductive structure and the optical laminate.
B: Partial breakage occurs between the conductive structure and the optical laminate, but does not pose any practical problems.
C: A break occurs between the conductive structure and the optical laminate, and is problematic in practical use.
　なお、図４～７は、加熱処理を行った後の実施例１～２、及び比較例１～２の画像表示パネルの表面を示すＳＥＭ画像である。これらの画像から、実施例１～２では、導通構造２０と光学積層体１０との間で破断がほとんど生じていない一方、比較例１～２では、破断が生じていることがわかる。 Note that Figures 4 to 7 are SEM images showing the surfaces of the image display panels of Examples 1 and 2 and Comparative Examples 1 and 2 after heat treatment. These images show that in Examples 1 and 2, almost no breaks occur between the conductive structure 20 and the optical laminate 10, whereas in Comparative Examples 1 and 2, breaks do occur.
［色抜け］
　さらに、上記の加熱処理後に、画像表示パネルの表面をＳＥＭで観察し、光学積層体の端部付近での色抜け（偏光フィルムの色抜け）を確認し、下記基準で評価した。
（評価基準）
　Ａ：色抜けの範囲が光学積層体の端部から５００μｍ以下である。
　Ｂ：色抜けの範囲が光学積層体の端部から５００μｍを超えている。 [Color loss]
Furthermore, after the above heat treatment, the surface of the image display panel was observed with an SEM to check for color loss near the edge of the optical laminate (color loss of the polarizing film), and evaluated according to the following criteria.
(Evaluation criteria)
A: The area of color loss is 500 μm or less from the end of the optical laminate.
B: The area of color loss exceeds 500 μm from the end of the optical laminate.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表１及び２中の略称は以下のとおりである。
　ＭＥＡ：２－メトキシエチルアクリレート
　ＢＡ：ｎ－ブチルアクリレート
　ＨＢＡ：４－ヒドロキシブチルアクリレート
　ＡＩＢＮ：アゾ系重合開始剤、２，２’－アゾビスイソブチロニトリル（キシダ化学社製）
　Ｃ／Ｌ：トリメチロールプロパン／トリレンジイソシアネート（東ソー社製、コロネートＬ）
　Ｄ１１０Ｎ：トリメチロールプロパン／キシリレンジイソシアネート（三井化学社製、タケネートＤ－１１０Ｎ）
　ＢＰＯ：ベンゾイルパーオキサイド（日本油脂社製、ナイパーＢＭＴ）
　ＡＳ１１０：１－エチル－３－メチルイミダゾリウムビス（フルオロスルホニル）イミド（エレクセルＡＳ－１１０、第一工業製薬社製）
　ＮＰ－１：太陽インキ社製、ＥＬＥＰＡＳＴＥ　ＮＰ－１
　ＳＸ－ＥＣＡ４８：セメダイン社製、ＳＸ－ＥＣＡ４８
　ＴＢ３３３１Ｄ：ＴｈｒｅｅＢｏｎｄ社製、ＴＢ３３３１Ｄ The abbreviations in Tables 1 and 2 are as follows.
MEA: 2-methoxyethyl acrylate BA: n-butyl acrylate HBA: 4-hydroxybutyl acrylate AIBN: azo-based polymerization initiator, 2,2'-azobisisobutyronitrile (Kishida Chemical Co., Ltd.)
C/L: Trimethylolpropane/tolylene diisocyanate (Tosoh Corporation, Coronate L)
D110N: Trimethylolpropane/xylylene diisocyanate (Takenate D-110N, manufactured by Mitsui Chemicals)
BPO: Benzoyl peroxide (Niper BMT, manufactured by NOF Corporation)
AS110: 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (Elexcel AS-110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
NP-1: ELEPASTE NP-1, manufactured by Taiyo Ink Co., Ltd.
SX-ECA48: Cemedine, SX-ECA48
TB3331D: ThreeBond, TB3331D
　表２からわかるとおり、導電性ペーストが、光学積層体の側面のうち、試験１により求めた寸法変化量が８０μｍ以下となる部分に塗布されて導通構造を形成しており、さらに、導電性ペーストについて、試験２により求めた破断伸度が５％以上である実施例の画像表示パネルでは、比較例と比べて、高温多湿環境下での導通構造と光学積層体との間での破断が十分に抑制されていた。実施例の画像表示パネルでは、導通構造と光学積層体との間での破断が抑制されているため、高温多湿環境を経た場合でも帯電防止性能が低下しにくいことが推定される。 As can be seen from Table 2, the conductive paste is applied to the portion of the side of the optical laminate where the dimensional change determined by Test 1 is 80 μm or less to form a conductive structure, and further, in the image display panel of the example where the breaking elongation of the conductive paste determined by Test 2 is 5% or more, breakage between the conductive structure and the optical laminate in a high temperature and high humidity environment was sufficiently suppressed compared to the comparative example. In the image display panel of the example, because breakage between the conductive structure and the optical laminate is suppressed, it is presumed that the antistatic performance is less likely to decrease even when exposed to a high temperature and high humidity environment.
　本発明の画像表示パネル用セットは、高温多湿環境を経た場合でも帯電防止性能が低下しにくい画像表示パネルを作製することに適している。 The image display panel set of the present invention is suitable for producing an image display panel whose antistatic performance is unlikely to deteriorate even when exposed to a high-temperature and high-humidity environment.

Claims (15)

  1. 　偏光フィルム及び粘着シートを有する光学積層体と、導電性ペーストと、を備える画像表示パネル用セットであって、
    　前記導電性ペーストは、前記光学積層体の側面のうち、下記試験１により求めた寸法変化量が８０μｍ以下となる部分に塗布されて導通構造を形成し、
    　前記導電性ペーストについて、下記試験２により求めた破断伸度が５％以上である、画像表示パネル用セット。
    　試験１：前記粘着シートを介して、前記光学積層体を無アルカリガラスに貼り付けて、温度８５℃、湿度８５％ＲＨの条件で２４０時間加熱処理を行う。前記加熱処理の前後での前記光学積層体の面方向における寸法変化量を特定する。
    　試験２：前記導電性ペーストから、厚さ２ｍｍの平膜を作製する。前記平膜を打ち抜き、ダンベル状１号形の試験片を作製する。前記試験片を引張試験機にセットし、初期のチャック間距離１０ｍｍ、引張速度３００ｍｍ／ｍｉｎの条件で引張試験を行い、前記試験片が破断したときの伸び（破断伸度）を特定する。     A set for an image display panel comprising an optical laminate having a polarizing film and an adhesive sheet, and a conductive paste,
    The conductive paste is applied to a portion of the side surface of the optical laminate where the dimensional change amount determined by the following Test 1 is 80 μm or less to form a conductive structure,
    The conductive paste has a breaking elongation of 5% or more as determined by the following Test 2.
    Test 1: The optical laminate is attached to non-alkali glass via the pressure-sensitive adhesive sheet, and is subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH. The amount of dimensional change in the planar direction of the optical laminate before and after the heat treatment is determined.
    Test 2: A flat film having a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
  2. 　前記破断伸度が２５％以上である、請求項１に記載のセット。 The set according to claim 1, wherein the breaking elongation is 25% or more.
  3. 　前記導電性ペーストは、金属及びバインダーを含む、請求項１に記載のセット。 The set of claim 1, wherein the conductive paste includes a metal and a binder.
  4. 　前記バインダーは、ポリエステル樹脂及びシリコーン樹脂からなる群より選ばれる少なくとも１つを含む、請求項３に記載のセット。 The set according to claim 3, wherein the binder includes at least one selected from the group consisting of polyester resin and silicone resin.
  5. 　前記バインダーは、エポキシ樹脂を実質的に含まない、請求項３に記載のセット。 The set according to claim 3, wherein the binder is substantially free of epoxy resin.
  6. 　前記金属は、銀を含む、請求項３に記載のセット。 The set of claim 3, wherein the metal includes silver.
  7. 　前記偏光フィルムは、２つの保護フィルムと、２つの前記保護フィルムの間に配置された偏光子とを有する、請求項１に記載のセット。 The set of claim 1, wherein the polarizing film has two protective films and a polarizer disposed between the two protective films.
  8. 　前記偏光子の厚さが６μｍ以上である、請求項７に記載のセット。 The set according to claim 7, wherein the polarizer has a thickness of 6 μm or more.
  9. 　前記粘着シートは、(メタ)アクリル系ポリマー（Ａ）を含む粘着剤組成物から形成される、請求項１に記載のセット。 The set according to claim 1, wherein the adhesive sheet is formed from an adhesive composition containing a (meth)acrylic polymer (A).
  10. 　前記(メタ)アクリル系ポリマー（Ａ）は、エーテル基含有単量体に由来する構成単位を有する、請求項９に記載のセット。 The set according to claim 9, wherein the (meth)acrylic polymer (A) has a structural unit derived from an ether group-containing monomer.
  11. 　前記粘着剤組成物は、帯電防止剤をさらに含む、請求項９に記載のセット。 The set according to claim 9, wherein the adhesive composition further comprises an antistatic agent.
  12. 　２５℃における前記粘着シートの貯蔵弾性率Ｇ’が９．０×１０4Ｐａ以上である、請求項１に記載のセット。 The set according to claim 1 , wherein the pressure-sensitive adhesive sheet has a storage modulus G′ at 25° C. of 9.0×10 4 Pa or more.
  13. 　前記粘着シートは、前記偏光フィルムと直接接している、請求項１に記載のセット。 The set according to claim 1, wherein the adhesive sheet is in direct contact with the polarizing film.
  14. 　画像表示セルと、
    　偏光フィルム及び粘着シートを備える光学積層体と、
    　導電性ペーストから形成され、前記光学積層体の側面のうち、下記試験１により求めた寸法変化量が８０μｍ以下となる部分に接触している導通構造と、
    を備え、
    　前記導電性ペーストについて、下記試験２により求めた破断伸度が５％以上である、画像表示パネル。
    　試験１：前記粘着シートを介して、前記光学積層体を無アルカリガラスに貼り付けて、温度８５℃、湿度８５％ＲＨの条件で２４０時間加熱処理を行う。前記加熱処理の前後での前記光学積層体の面方向における寸法変化量を特定する。
    　試験２：前記導電性ペーストから、厚さ２ｍｍの平膜を作製する。前記平膜を打ち抜き、ダンベル状１号形の試験片を作製する。前記試験片を引張試験機にセットし、初期のチャック間距離１０ｍｍ、引張速度３００ｍｍ／ｍｉｎの条件で引張試験を行い、前記試験片が破断したときの伸び（破断伸度）を特定する。     an image display cell;
    An optical laminate including a polarizing film and a pressure-sensitive adhesive sheet;
    A conductive structure formed from a conductive paste and in contact with a portion of the side surface of the optical laminate where the dimensional change amount determined by the following Test 1 is 80 μm or less;
    Equipped with
    The conductive paste has a breaking elongation of 5% or more as determined by the following Test 2.
    Test 1: The optical laminate is attached to non-alkali glass via the pressure-sensitive adhesive sheet, and is subjected to a heat treatment for 240 hours under conditions of a temperature of 85° C. and a humidity of 85% RH. The amount of dimensional change in the planar direction of the optical laminate before and after the heat treatment is determined.
    Test 2: A flat film having a thickness of 2 mm is prepared from the conductive paste. The flat film is punched out to prepare a dumbbell-shaped No. 1 test piece. The test piece is set in a tensile tester, and a tensile test is performed under conditions of an initial chuck distance of 10 mm and a tensile speed of 300 mm/min, and the elongation (breaking elongation) at which the test piece breaks is determined.
  15. 　タッチセンシング機能を内蔵する、請求項１４に記載の画像表示パネル。
          The image display panel according to claim 14, having a built-in touch sensing function.
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WO2014175463A1 (en) * 2013-04-24 2014-10-30 住友化学株式会社 Optical laminate and display device using same
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JP2011528448A (en) * 2008-07-18 2011-11-17 エルジー・ケム・リミテッド Liquid crystal display
WO2014175463A1 (en) * 2013-04-24 2014-10-30 住友化学株式会社 Optical laminate and display device using same
JP2017102403A (en) * 2015-12-04 2017-06-08 大日本印刷株式会社 Reflection display device
US20180003860A1 (en) * 2016-06-30 2018-01-04 Lg Display Co., Ltd. Polarizer, Display Device Having the Polarizer, and Method of Fabricating the Polarizer
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