JP5688338B2 - Adhesive, adhesive sheet and laminate for touch panel - Google Patents

Description

  The present invention relates to a pressure-sensitive adhesive used for a laminate for a touch panel, a pressure-sensitive adhesive sheet obtained by forming the pressure-sensitive adhesive into a sheet, and a laminate for a touch panel in which a member is attached using the pressure-sensitive adhesive sheet.

  The touch panels currently used in the mainstream are roughly classified into a resistive touch panel and a capacitive touch panel, both of which are laminates of various materials. The agent is being used. Since the touch panel unit is disposed on the outermost surface of the screen, high transparency is required, and further, characteristics such as high heat resistance and wet heat resistance are required. Specifically, the touch panel unit is a laminated body of various materials and is disposed on the outermost surface of the touch panel device, so that whitening may occur due to the ingress of moisture from the outside. There are problems such as foaming by entraining air and foaming by outgas generated from the material to be laminated.

  Moreover, in the resistive film type touch panel, which has been the mainstream of touch panels so far, various adhesives have been used for attaching polycarbonate (PC) or in-mold film (IMF).

  However, as a characteristic on the PC material, there is a characteristic that outgas is generated under high temperature conditions, there is a problem that foaming occurs under heat resistant conditions, and it is difficult to suppress whitening phenomenon of the adhesive layer due to moisture inflow under wet heat conditions. . Furthermore, since the IMF has a level difference on the order of submicrons, there is a problem that bubbles cannot be caught in the level difference and the bubble cannot be caught.

  Conventionally, the above problems have been solved by adding an acid component to the pressure-sensitive adhesive. In other words, the acid component has the function of dispersing the mixed water and preventing it from being deposited, and the water that has entered the pressure-sensitive adhesive layer is dispersed and not precipitated in the pressure-sensitive adhesive layer by the dispersion force of the acid component. The pressure-sensitive adhesive layer was prevented from being whitened and also formed with hydrogen bonds, so the generation of bubbles in heat-resistant foaming was suppressed by the high cohesive force due to the hydrogen bonds.

  By the way, recently, with the enhancement of functions such as multi-touch, capacitive touch panels are becoming mainstream in place of resistive touch panels. In this capacitive touch panel, the characteristics required for the resistive touch panel are of course necessary, but in addition, because the adhesive is in direct contact with the conductive layer forming the wiring, The property that the adhesive does not change the properties of the conductive layer is required. The conductive layer is formed of a metal or metal oxide such as indium tin oxide (ITO) or silver, and it has been used in the past because it causes corrosion due to contact with acid and its resistance value increases. It is not possible to use a means for securing characteristics such as heat resistance and heat-and-moisture resistance using an acid component.

  Regarding the corrosion of such transparent electrodes made of metals such as ITO or metal oxides, Patent Document 1 (Japanese Patent Laid-Open No. 2010-77287) discloses a polymer mainly composed of alkoxyalkyl acrylate. In this Patent Document 1, it is disclosed to use an alkoxyalkyl acrylate polymer having a weight average molecular weight of 400,000 to 1.6 million and not using a carboxyl group-containing monomer.

  Thus, by using a 400,000 to 1.6 million alkoxyalkyl acrylate polymer without using a carboxyl group-containing monomer, the corrosion of a transparent electrode made of a metal such as ITO or a metal oxide is improved to some extent. However, sufficient effects are not obtained with respect to performance such as wet heat whitening and heat resistant foaming. Furthermore, workability is not sufficient.

  Furthermore, since the weight average molecular weight of the polymer disclosed in Patent Document 1 is as large as 400,000 to 1.6 million, the viscosity of the polymer solution increases when the solid content increases when this is dissolved in a solvent to prepare a coating solution. Is too high. In the touch panel, an adhesive may be laminated on a support having a step by frame printing, and it is necessary to form a thick adhesive layer in order to follow the step. In the touch panel, a thick adhesive layer may be required to adhere a surface support and a conductive film such as ITO, but an alkoxyalkyl acrylate polymer having a weight average molecular weight of 400,000 to 1.6 million is required. Since it is not possible to prepare a coating solution with a high solid content if used, it is necessary to prepare a coating solution with a low solid content and apply it repeatedly. There is a problem that it is difficult to form an adhesive layer.

  On the other hand, the pressure-sensitive adhesive may be used in the form of a transfer tape in which a pressure-sensitive adhesive layer is formed between peelable films. Such a transfer tape is used by peeling off the peelable film and transferring it to the touch panel member. However, the adhesive layer of the transfer tape has already been formed with a crosslinked structure in the adhesive layer, so It becomes inferior to following ability. Therefore, there is a demand for a pressure-sensitive adhesive sheet that has an appropriate flexibility for bonding to a film or a substrate even when cross-linked and has reduced foaming due to entrainment at the time of bonding. Patent Document 2 describes a pressure-sensitive adhesive composition in which yellowing resistance is improved using an aliphatic isocyanate-based crosslinking agent. A pressure-sensitive adhesive sheet cured using an aliphatic isocyanate-based crosslinking agent is superior in flexibility to a pressure-sensitive adhesive sheet cured using a crosslinking agent having an aromatic ring. However, the acrylic polymer to be crosslinked described in Patent Document 2 has a weight average molecular weight of 400,000 or more and 1.6 million or less, and has the above-mentioned problems.

  Further, the surface of polyethylene terephthalate or polycarbonate constituting the surface support of the touch panel is often hard-coated. Therefore, the pressure-sensitive adhesive sheet is also required to have good adhesion to the hard coat layer.

JP 2010-77287 A JP 2010-215923 A

  The present invention relates to a pressure-sensitive adhesive for a touch panel having a conductive film made of a metal or a metal oxide, which is excellent in heat resistance, moist heat resistance, and step followability, and is not corrosive to a metal or metal oxide. It aims at providing the sheet | seat and the laminated body for touchscreens using the same.

  Another object of the present invention is to provide a pressure-sensitive adhesive or pressure-sensitive adhesive sheet with good workability.

The present invention includes, for example, the following [1] to [29].
[1] Components (a-1) and (a-2) shown below
(a-1) Alkoxy (meth) acrylate 20 to 99.9% by weight
(a-2) Monomer having a crosslinkable functional group 0.1 to 10% by weight
An acrylic polymer (A) having a weight average molecular weight of not less than 50,000 and less than 400,000, which is substantially free of acidic groups, obtained by copolymerization of a monomer containing all monomers (100% by weight of all monomers); A pressure-sensitive adhesive comprising 0.1 to 5 parts by weight of an aliphatic isocyanate-based crosslinking agent (B) with respect to 100 parts by weight of the polymer (A).
[2] The pressure-sensitive adhesive according to [1], wherein the aliphatic isocyanate-based crosslinking agent (B) has three or more isocyanate groups in one molecule.
[3] The pressure-sensitive adhesive according to [1] or [2], wherein the monomer (a-2) having a crosslinkable functional group forming the acrylic polymer (A) is a hydroxyl group-containing monomer.
[4] Any one of [1] to [3], wherein the acrylic polymer (A) is obtained by further copolymerizing (a-3) a monomer containing 5% by weight or less of a nitrogen-containing monomer. The pressure-sensitive adhesive according to one item.
[5] The (a-3) nitrogen-containing monomer is at least one selected from the group consisting of an amino group-containing monomer, an amide group-containing monomer, a nitrogen-based heterocyclic ring-containing monomer, and a cyano group-containing monomer. The adhesive according to [4].
[6] The pressure-sensitive adhesive according to any one of [1] to [5], wherein the pressure-sensitive adhesive is a pressure-sensitive adhesive for a capacitive touch panel in direct contact with a metal or metal oxide. Agent.
[7] Any one of [1] to [5], wherein the pressure-sensitive adhesive is a pressure-sensitive adhesive for a capacitive touch panel in direct contact with the hard coat layer on the surface support of the touch panel. The pressure-sensitive adhesive according to item.
[8] The pressure-sensitive adhesive according to [7], wherein the hard coat layer is of a silicone type.
[9] Components (a-1) and (a-2) shown below
(a-1) Alkoxy (meth) acrylate 20 to 99.9% by weight
(a-2) Monomer having a crosslinkable functional group 0.1 to 10% by weight
An acrylic polymer (A) having a weight average molecular weight of not less than 50,000 and less than 400,000, which is substantially free of acidic groups, obtained by copolymerization of a monomer containing all monomers (100% by weight of all monomers); Formed from an adhesive containing 0.1 to 5 parts by weight of an aliphatic isocyanate-based crosslinking agent (B) with respect to 100 parts by weight of the polymer (A),
A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer having a gel fraction of 40 to 80% by weight and a thickness of 10 to 1000 μm.
[10] The pressure-sensitive adhesive sheet according to [9], wherein the aliphatic isocyanate crosslinking agent (B) has three or more isocyanate groups in one molecule.
[11] The pressure-sensitive adhesive sheet according to [9] or [10], wherein the monomer (a-2) having a crosslinkable functional group forming the acrylic polymer (A) is a hydroxyl group-containing monomer.
[12] Any of [9] to [11], wherein the acrylic polymer (A) is obtained by copolymerizing a monomer further containing (a-3) a nitrogen-containing monomer of 5% by weight or less. The pressure-sensitive adhesive sheet according to one item.
[13] The nitrogen-containing monomer (a-3) is at least one selected from the group consisting of an amino group-containing monomer, an amide group-containing monomer, a nitrogen-based heterocyclic ring-containing monomer, and a cyano group-containing monomer. The pressure-sensitive adhesive sheet according to [12].
[14] Any one of [9] to [13], wherein the pressure-sensitive adhesive forming the pressure-sensitive adhesive sheet is a pressure-sensitive adhesive for a capacitive touch panel in direct contact with a metal or metal oxide. The pressure-sensitive adhesive sheet according to item.
[15] The pressure-sensitive adhesive forming the pressure-sensitive adhesive sheet is a pressure-sensitive adhesive for a capacitive touch panel in direct contact with a hard coat layer on a surface support of the touch panel [9] to [14] ] The adhesive sheet as described in any one of.
[16] The pressure-sensitive adhesive sheet according to [15], wherein the hard coat layer is of a silicone type.
[17] The pressure-sensitive adhesive sheet according to any one of [9] to [16], wherein a cover film subjected to a release treatment is disposed on at least one surface of the pressure-sensitive adhesive sheet.
[18] Components (a-1) and (a-2) shown below
(a-1) Alkoxy (meth) acrylate 20 to 99.9% by weight
(a-2) Monomer having a crosslinkable functional group 0.1 to 10% by weight
An acrylic polymer (A) having a weight average molecular weight of not less than 50,000 and less than 400,000, which is substantially free of acidic groups, obtained by copolymerization of a monomer containing all monomers (100% by weight of all monomers); Formed from an adhesive containing 0.1 to 5 parts by weight of an aliphatic isocyanate-based crosslinking agent (B) with respect to 100 parts by weight of the polymer (A),
An edge of the surface facing the pressure-sensitive adhesive sheet on one surface of the pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer having a gel fraction of 40 to 80% by weight and a thickness of 10 to 1000 μm A frame-printed surface support is attached, and a transparent conductive film made of metal or metal oxide, metal with electrode support or metal oxide is attached to the other surface of the pressure-sensitive adhesive sheet A laminate for a touch panel characterized by the following.
[19] The touch panel laminate according to [18], wherein the touch panel laminate is a member forming a capacitive touch panel.
[20] The touch panel laminate as described in [18] or [19], wherein the thickness of the frame printing is in the range of 10 to 50 μm.
[21] The transparent conductive film is a wiring pattern using ITO, ATO, or tin oxide, and the pressure-sensitive adhesive sheet is in direct contact with the wiring pattern [18] to [20] The laminated body for touchscreens as described in any one of these.
[22] The laminate for a touch panel as described in any one of [18] to [21], wherein the thickness of the surface support is in the range of 25 to 2000 μm.
[23] The laminate for a touch panel according to any one of [18] to [22], wherein the transparent conductive film has a thickness in a range of 10 to 100 nm.
[24] The laminate for a touch panel according to any one of [18] to [23], wherein the aliphatic isocyanate-based crosslinking agent (B) has three or more isocyanate groups in one molecule. body.
[25] Any one of [18] to [24], wherein the monomer (a-2) having a crosslinkable functional group forming the acrylic polymer (A) is a hydroxyl group-containing monomer. Laminate for touch panel.
[26] Any one of [18] to [25], wherein the acrylic polymer (A) is obtained by copolymerizing a monomer further containing (a-3) a nitrogen-containing monomer of 5% by weight or less. The laminated body for touchscreens as described in one term.
[27] The (a-3) nitrogen-containing monomer is at least one selected from the group consisting of an amino group-containing monomer, an amide group-containing monomer, a nitrogen-based heterocyclic ring-containing monomer, and a cyano group-containing monomer. The laminate for a touch panel according to [26].
[28] The laminate for a touch panel according to any one of [18] to [27], wherein the pressure-sensitive adhesive sheet is in direct contact with a hard coat layer on a surface support of the touch panel.
[29] The laminate for a touch panel as described in [28], wherein the hard coat layer is a silicone type.

Since the pressure-sensitive adhesive of the present invention does not substantially contain an acid component, it is possible to effectively suppress deterioration due to corrosion of a metal or metal oxide such as ITO or silver.
Furthermore, the adhesive of the present invention, the weight-average molecular weight (Mw) less than 50,000 400,000 can be kept solid at a high concentration in the solvent, a sufficient thickness in a single coating step Can be painted.

  Since the crosslinked structure is formed by the aliphatic isocyanate-based crosslinking agent, the pressure-sensitive adhesive of the present invention is excellent in heat resistance, moist heat resistance and flexibility, and has very good step followability. It is. Furthermore, the adhesiveness to the hard-coated film is also good.

  Therefore, the pressure-sensitive adhesive of the present invention, the pressure-sensitive adhesive sheet having this pressure-sensitive adhesive as a pressure-sensitive adhesive layer, and the touch panel laminate using this pressure-sensitive adhesive sheet are corrosive to a transparent conductive film made of a metal such as ITO or silver or a metal oxide. Is less likely to cause whitening and foaming.

FIG. 1 is a cross-sectional view schematically showing an example of a touch panel unit in a resistive film type touch panel incorporating the laminate for a touch panel of the present invention. FIG. 2 is a cross-sectional view schematically showing an example of a touch panel unit in a capacitive touch panel incorporating the laminate for a touch panel of the present invention. FIG. 3 is a cross-sectional view schematically showing an example of the configuration of the end of the capacitive touch panel. FIG. 4 is a cross-sectional view schematically showing the adhesive state of the adhesive sheet to the frame print portion formed at the end of the touch panel. FIG. 5 is a cross-sectional view for explaining the state of foaming that occurs in the laminate for a touch panel. FIG. 6 is a cross-sectional view for explaining the occurrence of a whitening phenomenon that occurs in the laminate for a touch panel.

Next, the pressure-sensitive adhesive, pressure-sensitive adhesive sheet and touch panel laminate of the present invention will be specifically described.
The pressure-sensitive adhesive of the present invention comprises an acrylic polymer (A) and an aliphatic isocyanate cross-linking agent (B).

In the present invention, the acrylic polymer (A) comprises the following components (a-1) and (a-2)
(a-1) alkoxy (meth) acrylate,
(a-2) A polymer obtained by copolymerization with a monomer having a crosslinkable functional group.

  Examples of the (a-1) alkoxy (meth) acrylate constituting the acrylic polymer (A) used here include methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, Methoxybutyl (meth) acrylate, ethoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate, ethoxybutyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxy Mention may be made of triethylene glycol (meth) acrylate and ethoxytriethylene glycol (meth) acrylate. Among these (a-1) alkoxy (meth) acrylates, methoxyethyl (meth) acrylate and methoxydiethylene glycol (meth) acrylate are preferably used, and these can be used alone or in combination.

In the acrylic polymer of the present invention, the (a-1) alkoxy (meth) acrylate is 20 to 99.9% by weight, preferably 30 to 99.1% by weight, more preferably 50 to 98.3% by weight. Copolymerized in quantity. (a-1) the alkoxy (meth) acrylate is greater than 99.9 wt%, can not be achieved necessarily sufficient crosslink density Ri using less monomer having a functional group. On the other hand, if it is less than 20% by weight, moisture precipitation cannot be suppressed during wet heat, and the pressure-sensitive adhesive layer is whitened, resulting in abnormal appearance.

  The monomer (a-2) having a crosslinkable functional group that is copolymerized with the (a-1) alkoxy (meth) acrylate is preferably a hydroxyl group-containing monomer. As the hydroxyl group-containing monomer, a (meth) acrylate compound having a hydroxyl group as a functional group is preferable. Examples of such a (meth) acrylate compound having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate. ) Acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and 8-hydroxyoctyl (meth) acrylate. As the (meth) acrylate compound having a hydroxyl group as described above, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable, and these (meth) acrylate compounds having a hydroxyl group may be used alone or in combination. Can be used together.

  In the acrylic polymer (A) used in the present invention, (a-2) the monomer having a crosslinkable functional group is 0.1 to 10% by weight, preferably 0.8 to 9% by weight, more preferably Copolymerized in an amount in the range of 1.2 to 6% by weight.

  If the amount of the monomer having a crosslinkable functional group is less than the above, a crosslinked structure due to the aliphatic isocyanate-based crosslinking agent may not be sufficiently formed, and if the amount of the monomer having a crosslinkable functional group is more than 10% by weight, The characteristics as an acrylic polymer may not be sufficiently developed.

  Furthermore, the acrylic polymer of the present invention is not limited to the above-mentioned (a-1) alkoxy (meth) acrylate and (a-2) monomer having a crosslinkable functional group, as long as the properties of the acrylic polymer are not impaired. Other acrylic monomers may be copolymerized.

  Examples of other monomers forming the acrylic polymer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, and n-butyl (meth) ) Acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate , Nonyl (meth) acrylate, decyl (meth) acrylate, undeca (meth) acrylate, and dideca (meth) acrylate. These (meth) acrylates can be used alone or in combination. Among these, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methyl (meth) acrylate, and iso-butyl (meth) acrylate are preferably used. These alkyl (meth) acrylates are acrylic polymers. In (A), it can be used in the range of 0 to 79.9% by weight, preferably 0 to 69.1% by weight, more preferably 0 to 48.3% by weight.

  Furthermore, the acrylic polymer (A) used in the present invention improves the cohesive strength of the pressure-sensitive adhesive, and further promotes crosslinking with an isocyanate-based crosslinking agent. It is preferable. As the nitrogen-containing monomer, it is preferable to use at least one selected from the group consisting of an amino group-containing monomer, an amide group-containing monomer, a nitrogen-based heterocyclic ring-containing monomer, and a cyano group-containing monomer.

Examples of amino group-containing monomers include dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate.
Examples of amide group-containing monomers include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, and N-hexyl (meth) acrylamide. Can do.

Furthermore, examples of the nitrogen-based heterocyclic ring-containing monomer include vinyl pyrrolidone, acryloyl morpholine, and vinyl caprolactam.
Examples of the cyano group-containing monomer include cyano (meth) acrylate.

  Such (a-3) nitrogen-containing monomer is copolymerized in the acrylic polymer in an amount of preferably 5 wt% or less, more preferably 0.1 to 4 wt%, most preferably 0.5 to 3 wt%. ing.

  Furthermore, the acrylic polymer (A) used in the present invention can be copolymerized with other monomers within a range not impairing the effects of the present invention. Other monomers include: vinyl acetate; (meth) acrylonitrile; cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate; styrene, methylstyrene, dimethylstyrene, trimethylstyrene, propylstyrene, butylstyrene, Alkyl styrene such as xyl styrene, heptyl styrene and octyl styrene, fluoro styrene, chloro styrene, bromo styrene, dibromo styrene, iodinated styrene, nitro styrene, acetyl styrene, methoxy styrene, and other styrenic monomers; glycidyl acrylate, glycidyl methacrylate Further, a methyl methacrylate polymer having an unsaturated group, a t-butyl methacrylate polymer having an unsaturated group, and a stity having an unsaturated group Examples thereof include macromonomers such as a len polymer.

  The acrylic polymer (A) used in the present invention has substantially no acidic group. Here, “having no acidic group” means that no acidic group is intentionally added, and it is usually 0.5 or less in terms of acid value. Examples of the monomer having an acidic group include a monomer having a carboxyl group such as (meth) acrylic acid, maleic acid, and itaconic acid, a monomer having a phosphoric acid group, and a monomer having a sulfuric acid group. In the present invention, the acrylic polymer (A) is not copolymerized with the above acidic group-containing monomer. Since the acidic group-containing monomer is not copolymerized in this way, the acrylic polymer (A) of the present invention does not corrode even if it is in direct contact with a wiring made of a metal or metal oxide. This adhesive can be given a characteristic that the resistance value of the wiring is not changed over a long period of time.

Furthermore, the acrylic monomer (A) used in the present invention has a weight average molecular weight of 50,000 or more and less than 400,000, preferably 100,000 to 380,000.
The acrylic polymer (A) can be produced by a known method, but is preferably produced by solution polymerization. In the solution polymerization, for example, ethyl acetate, methyl ethyl ketone, toluene, acetone or the like can be used as a polymerization solvent. Specifically, a polymerization solvent and a monomer are charged into a reaction vessel, a polymerization initiator is added in an inert gas atmosphere such as nitrogen gas, and the reaction is performed at a reaction temperature of about 50 to 90 ° C. and allowed to react for 4 to 20 hours.

  Examples of the reaction initiator used for solution polymerization include azo initiators and peroxide initiators. These initiators are usually used in an amount in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the monomer. Further, a polymerization initiator, a chain transfer agent, a monomer, and a solvent may be appropriately added during the polymerization reaction.

Under the above conditions, the weight average molecular weight, according to the known art, can be adjusted type of solvent used, the type and amount of the polymerization initiator, reaction time, by adjust the reaction conditions such as reaction temperature .

  The pressure-sensitive adhesive of the present invention further contains an aliphatic isocyanate crosslinking agent (B). The aliphatic isocyanate-based cross-linking agent (B) maintains the flexibility of the pressure-sensitive adhesive sheet even after cross-linking and improves the pressure-sensitive adhesiveness of the pressure-sensitive adhesive sheet to a hard coat treated surface such as polyethylene terephthalate.

  Examples of the aliphatic isocyanate-based crosslinking agent (B) used in the present invention include compounds having two or more isocyanate groups in one molecule such as hexamethylene diisocyanate and tetramethylene diisocyanate, and further known polyether polyols and Examples thereof include compounds having two or more isocyanate groups in one molecule of a urethane prepolymer type obtained by addition reaction with polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene and the like. Among them, a compound having three or more isocyanate groups in one molecule is preferable in that it can improve the step following property of the attachment surface and improve the heat-resistant foaming property. Examples of the compound having three or more isocyanate groups in one molecule include adduct type compounds having two or more isocyanate groups in one molecule, and compounds having two or more isocyanate groups in one molecule. Compound obtained by addition reaction with polyhydric alcohol such as pentaerythritol, isocyanurate compound of compound having two or more isocyanate groups in one molecule, biuret type of compound having two or more isocyanate groups in one molecule Compounds. Examples of the adduct type compound include compounds obtained by addition reaction of a compound having two or more isocyanate groups in one molecule with trimethylolpropane.

Such aliphatic isocyanate crosslinking agents (B) can be used alone or in combination. The content of the aliphatic isocyanate crosslinking agent (B) in the pressure-sensitive adhesive of the present invention is 0.1 to 5 parts by weight, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the acrylic polymer (A). It is.

Thus, by mix | blending an aliphatic isocyanate type crosslinking agent (B), the cohesion force of an adhesive improves and it can suppress the expansion | swelling of the bubble slightly involved at the time of sticking.
The pressure-sensitive adhesive of the present invention preferably contains a low molecular weight substance containing a structural unit derived from a nitrogen-containing monomer. Examples of the nitrogen-containing monomer include those exemplified above. The monomer other than the nitrogen-containing monomer constituting the low molecular weight substance is not particularly limited as long as it is a monomer having an unsaturated group, but preferably includes an acrylic monomer such as (meth) acrylate, a styrene monomer, and the like. The weight average molecular weight of the low molecular weight body is preferably 5,000 or more and less than 50,000. When the pressure-sensitive adhesive of the present invention contains the low molecular weight substance, it has an effect of improving the cohesive force of the pressure-sensitive adhesive and further promoting the crosslinking by the isocyanate-based crosslinking agent.

  In the pressure-sensitive adhesive of the present invention, an antioxidant, a metal corrosion inhibitor, a light stabilizer, a tackifier, a plasticizer, an antistatic agent, a crosslinking accelerator, as long as the effect of the pressure-sensitive adhesive of the present invention is not impaired. A rework agent or the like can also be blended.

  The pressure-sensitive adhesive thus obtained can be used for bonding various members by coating and drying after dilution to an appropriate concentration, in the same manner as known pressure-sensitive adhesives. The coating solution containing the acrylic polymer (A) and the aliphatic isocyanate crosslinking agent (B) used in the present invention in the solvent has a low weight average molecular weight (Mw) of the acrylic polymer (A). The concentration of non-volatile components can be easily adjusted in a solvent such as methyl ethyl ketone, acetone or toluene. Therefore, by using the pressure-sensitive adhesive of the present invention, the thickness of the pressure-sensitive adhesive after coating can be easily set to a desired thickness. In particular, since the pressure-sensitive adhesive of the present invention can easily prepare a solution having a high nonvolatile content, for example, the nonvolatile content can be adjusted within a range of 10 to 70%, preferably 30 to 60%. The desired thickness can be achieved with a small number of coatings. Further, by using a solution having a high nonvolatile content as described above, the leveling property of the coating film after coating and drying is improved, and the drying time is shortened and the workability is improved. Furthermore, since the amount of volatile solvent is small, the burden on the environment is also reduced.

  Utilizing such characteristics, the pressure-sensitive adhesive sheet of the present invention can be obtained by applying the pressure-sensitive adhesive to a thickness in the range of 10 to 1000 μm, preferably in a range of 25 to 500 μm.

  This pressure-sensitive adhesive sheet is usually made of a support (eg, release-treated PET or the like) whose surface has been subjected to a pressure-sensitive adhesive coating solution whose non-volatile content is adjusted to 10 to 70%, preferably 30 to 60%. The surface is coated on the surface of the pressure-sensitive adhesive layer after the solvent is removed by coating the surface so that the dry thickness is in the range of 25-1000 μm, preferably in the range of 25-500 μm. It is obtained by sticking the peel-treated cover film and usually curing at a temperature of 0 to 50 ° C. for 1 to 10 days.

The gel fraction of the pressure-sensitive adhesive layer thus obtained is in the range of 40 to 80%, preferably 60 to 70%.
The pressure-sensitive adhesive sheet thus obtained can be attached to various members, and is particularly suitable for attaching a touch panel member to which different types of members are attached.

As shown in FIGS. 1 and 2, the touch panel unit includes a resistive touch panel unit (see FIG. 1) and a capacitive touch panel unit (see FIG. 2).
FIG. 1 shows an example of a resistive film type touch panel unit 10-1. As shown in FIG. 1, the resistive touch panel unit 10-1 includes an upper laminated body 11-1 and a lower laminated body 13-1 so that a gap 34 is formed by the bonding agent 30. A spacer 32 is disposed in the space 34 in order to effectively secure a space.

  In the upper laminate 11-1, a transparent conductive film 27-1 made of metal or metal oxide is disposed facing the gap 34. This transparent conductive film 27-1 is made of a conductive material having transparency such as ITO, ATO, tin oxide, and is usually an upper electrode support made of polyethylene terephthalate (PET) or glass as shown in FIG. It is formed on the surface of 25-1.

  A surface support 21-1 is disposed on the outermost surface of the upper laminate, and this surface support 21-1 is usually highly transparent glass or polycarbonate, polyethylene terephthalate (PET), polymethyl methacrylate (PMMA). , A transparent film such as cycloolefin polymer (COP), or a transparent plate. In order to adhere the surface support 21-1 and the upper electrode support 25-1, an adhesive layer 23-1 made of the adhesive of the present invention is formed. It is preferable that a hard coat layer is provided on the surfaces of the upper electrode support 25-1 and the surface support 21-1 that are in contact with the pressure-sensitive adhesive layer 23-1. As the hard coat layer, those usually used can be used without limitation, but even a silicone hard coat layer, which is usually difficult to adhere with an acrylic pressure-sensitive adhesive, is preferable because the adhesive force is improved.

  Similarly, the lower laminate 13-1 is formed with a transparent conductive film 27-2 made of metal or metal oxide so as to face the gap 34. The transparent conductive film 27-2 is made of ITO, ATO, It is made of a conductive material having transparency such as tin oxide, and is usually formed on the surface of a lower electrode support 25-2 made of polyethylene terephthalate (PET) or glass as shown in FIG.

  A deep surface support 21-2 is formed at the deepest portion of the lower laminate 13-1 so as to face the surface of the display. The deep surface support 21-2 is made of glass, polycarbonate, polyethylene terephthalate ( It is formed from a highly transparent member such as PET), polymethyl methacrylate (PMMA), and cycloolefin polymer (COP).

  In the lower laminate 13-1, an adhesive layer 23-2 made of the adhesive of the present invention is formed in order to bond the deep surface support 21-2 and the lower electrode support 25-2. It is preferable that a hard coat layer is provided on the surface of the lower electrode support 25-2 and the surface support 21-2 that contacts the adhesive layer 23-2. As the hard coat layer, those usually used can be used without limitation. Even in the case of an adherend such as a silicone-based hard coat layer that cannot be obtained with a normal acrylic pressure-sensitive adhesive, the acrylic pressure-sensitive adhesive of the present invention preferably exhibits a sufficient pressure-sensitive adhesive strength. Used.

Moreover, the adhesive of this invention may be used as the bonding agent 30. FIG.
In the transparent conductive films 27-1 and 27-2, when a pressure is applied from above the surface support 21-1, the gap 34 in the portion where the pressure is applied disappears and the transparent conductive film 27- 1 and 27-2 are in contact with each other and are energized to detect the pressurized portion.

  In the resistive touch panel unit 10-1, the thickness of the surface support 21-1 is usually 25 to 2000 μm, and the thickness of the upper transparent conductive film 27-1 is usually 10 to 100 nm. The thickness of the body 25-1 is usually 25 to 2000 μm. As described above, the thickness of the pressure-sensitive adhesive layer 23-1 for laminating them is in the range of 10 to 1000 μm.

  Similarly, in the resistive film type touch panel unit, the thickness of the deep surface support 21-2 is usually 25 to 2000 μm, and the thickness of the lower transparent conductive film 27-2 is usually 10 to 100 nm. The thickness of the support 25-2 is usually 25 to 2000 μm. As described above, the thickness of the pressure-sensitive adhesive layer 23-2 on which these are laminated is in the range of 10 to 1000 μm.

Further, in the resistive film type touch panel unit 10-1, the width of the gap formed at the center is usually in the range of 100 to 300 μm.
On the other hand, the capacitive touch panel unit 10-2 generally includes an upper laminated body 15-1 and a lower laminated body 15-2 sandwiching a central support 60 made of a highly transparent member such as glass or polycarbonate. Often has an arranged structure.

  In the upper laminate 15-1 of the capacitive touch panel 10-2, a transparent conductive film 57-1 is disposed in contact with the central support 60, and the outermost surface is a cover glass or polyethylene terephthalate (PET). A surface support 51-1 made of a light transmissive member such as polycarbonate (PC), polymethyl methacrylate (PMMA), or cycloolefin polymer (COP) is disposed. The pressure-sensitive adhesive layer 53-1 is in direct contact with the transparent conductive film 57-1. The transparent conductive film 57-1 is formed of a conductive material having transparency such as ITO, ATO, or tin oxide.

  The pressure-sensitive adhesive layer 53-1 made of the pressure-sensitive adhesive of the present invention is disposed so as to adhere the transparent conductive film 57-1 and the surface support 51-1, and the pressure-sensitive adhesive layer of the surface support 51-1 is disposed. A hard coat layer is preferably provided on the surface in contact with 53-1. As the hard coat layer, those usually used can be used without limitation. Even in the case of an adherend such as a silicone-based hard coat layer that cannot be obtained with a normal acrylic pressure-sensitive adhesive, the acrylic pressure-sensitive adhesive of the present invention preferably exhibits a sufficient pressure-sensitive adhesive strength. Used.

  On the other hand, in the lower laminate 15-2 in the capacitive touch panel unit 10-2, a transparent conductive film 57-2 is disposed in contact with the central support 60, and in the deepest part, a cover glass or polyethylene is provided. A surface support 51-2 made of a light transmitting member such as terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), cycloolefin polymer (COP) is disposed. The transparent conductive film 57-2 is made of a conductive material having transparency such as ITO, ATO, or tin oxide. A pressure-sensitive adhesive layer 53-2 made of the pressure-sensitive adhesive of the present invention is disposed so as to bond the transparent conductive film 57-2 and the deepest surface support 51-2. In direct contact with the transparent conductive film 57-2. It is preferable that a hard coat layer is provided on the surface of the surface support 51-2 that contacts the pressure-sensitive adhesive layer 53-2. As the hard coat layer, those usually used can be used without limitation. Even in the case of an adherend such as a silicone-based hard coat layer that cannot be obtained with a normal acrylic pressure-sensitive adhesive, the acrylic pressure-sensitive adhesive of the present invention preferably exhibits a sufficient pressure-sensitive adhesive strength. Used.

In the capacitive touch panel unit 10-2, the deepest surface support 51-2 is arranged to face the display.
In the capacitive touch panel unit 10-2, the thickness of the upper surface support 51-1 is usually 25 to 2000 μm, and the thickness of the upper transparent conductive film 57-1 is usually 10 to 100 nm. As described above, the thickness of the pressure-sensitive adhesive layer 53-1 for adhering is 25 to 1000 μm. In the lower laminate 15-2, the thickness of the lower transparent conductive film 57-2 is usually 10 to 100 nm, and the thickness of the deepest surface support 51-2 is usually 25 to 2000 μm. As described above, the thickness of the pressure-sensitive adhesive layer for adhering is 25 to 1000 μm. Further, the thickness of the central support 60 between the upper laminate 15-1 and the lower laminate 15-2 is usually in the range of 25 to 1000 μm.

  The upper transparent conductive film 57-1 and the lower transparent conductive film 57-2 form a circuit. In the capacitive touch panel unit 10-2 shown in FIG. 2, the upper transparent conductive film 57-1 is formed by two series of circuits provided independently in the X-axis direction and the Y-axis direction, respectively. The lower stacked body 15-2 can be omitted.

In the capacitive touch panel, the contact position is detected by reading the change in the capacitance of the contact portion caused by the finger touching the surface of the touch panel unit 10-2.
For the touch panel unit as described above, for example, frame printing is performed on the surface of the edge surface support 51-1 that is in contact with the adhesive shown by A in FIG. This frame printing portion is shown in an enlarged manner in FIG. In FIG. 3, the frame printing portion is indicated by the number 62. The thickness (t ₀ ) of the frame printing portion 62 is normally 10 to 50 μm, and its cross section is formed in a substantially rectangular shape. Since the pressure-sensitive adhesive layer 53-1 is formed by sticking the above-mentioned pressure-sensitive adhesive sheet of the present invention to the surface support 51-1, the pressure-sensitive adhesive layer formed on the pressure-sensitive adhesive sheet is hard and has poor step following ability. As shown in FIG. 4 (a), the adhesive layer 53-1 is located between the surface support 51-1 and the frame printing portion 62 at the end of the frame printing portion 62 and between the surface support 51-1. A gap 64 that is not in contact with any of the edges is formed. Originally, as shown in FIG. 4 (b), the adhesive layer 53-1 must be in close contact with the edge portions of the surface support 51-1 and the frame printing portion 62 without forming the gap 64.

  However, in the pressure-sensitive adhesive based on a pressure-sensitive adhesive having a weight average molecular weight of 400,000 to 1.6 million as in the past, the shape of the pressure-sensitive adhesive layer cannot be changed due to such a very fine shape change, and the gap 64 is formed. It will be formed.

  The pressure-sensitive adhesive layer 53-1 constituting the touch panel member of the present invention in which the surface support, the pressure-sensitive adhesive layer, and the transparent conductive film (which may have a support) are laminated has a specific composition as described above. In addition, by using an acrylic polymer (A) having a weight average molecular weight (Mw) of 50,000 or more and less than 400,000, and crosslinking these with an aliphatic isocyanate crosslinking agent (B), extremely excellent step following property The void 64 is not formed around the frame printing portion 62.

  Further, when the member for touch panel of the present invention uses a member that easily generates outgas such as polycarbonate (PC) as the support 51-2 as shown in FIG. As a result, outgas from the support may be generated, and bubbles 66 may be generated between the support and the adhesive layer. Even if a support that does not generate outgas is used, bubbles 68 may be involved when the support and the pressure-sensitive adhesive layer are bonded to each other, and if this bubble grows due to a temperature change, it will cause foaming. The pressure-sensitive adhesive of the present invention uses an acrylic polymer (A) having a specific composition and a weight average molecular weight (Mw) of 50,000 or more and less than 400,000, and these are aliphatic isocyanate crosslinking agents (B). Since it is cross-linked, it has a very high cohesive force, and the foaming due to outgas and the growth of entrained bubbles as described above can be suppressed by the high cohesive force. Therefore, the foaming as described above can be hardly observed in the touch panel member of the present invention.

  Moreover, in the member for touch panels, when the member is left under durability test conditions (60 ° C., 90%), moisture may enter from the support and the end as shown in FIG. Under the condition where the temperature is high, the infiltrated moisture does not precipitate, but when the temperature is lowered, the infiltrated moisture is precipitated, the touch panel member is whitened, and the haze is remarkably increased. The pressure-sensitive adhesive layer forming the touch panel member of the present invention has a specific composition, so that the precipitation of moisture is suppressed even when moisture enters from the support layer, and therefore haze increase due to the whitening phenomenon occurs extremely. Hateful.

  Further, since the pressure-sensitive adhesive of the present invention contains substantially no acidic group, even if this pressure-sensitive adhesive directly contacts a transparent conductive film made of metal or metal oxide, the resistance value of the transparent conductive film changes. Is about 10% at the maximum, and this amount of change is an amount which does not cause any problem in driving the touch panel.

  As described above, the member for a touch panel of the present invention comprises a main alkyl polymer (A) having a specific composition as an adhesive and having a weight average molecular weight of 50,000 or more and less than 400,000 and an aliphatic isocyanate crosslinking agent (B). The support and the transparent conductive film are adhered to each other using the pressure-sensitive adhesive having an excellent step following ability, and no void is formed in the frame printing portion formed on the edge. Further, both foaming due to entrainment and foaming due to outgas can be suppressed, and moisture is hardly precipitated, so that the pressure-sensitive adhesive layer is not whitened and haze is not increased.

EXAMPLES Next, the present invention will be described in more detail with reference to examples of the present invention, but the present invention is not limited thereto.
By the method shown below, the weight average molecular weight, gel fraction, wet heat whitening property, heat-resistant foaming property, ITO corrosiveness, step following property and adhesive strength of the pressure-sensitive adhesive were measured.
〔Measuring method〕
<Molecular weight>
The weight average molecular weight (Mw) in terms of standard polystyrene was determined using gel permeation chromatography (GPC).
Measuring condition apparatus: HLC-8120GPC (manufactured by Tosoh Corporation)
Column: The following five columns were used.

TSK-GEL HXL-H (guard column, manufactured by Tosoh Corporation)
TSK-GEL G7000HXL (manufactured by Tosoh Corporation)
TSK-GEL GMHXL (manufactured by Tosoh Corporation)
TSK-GEL GMHXL (manufactured by Tosoh Corporation)
TSK-GEL G2500HXL (manufactured by Tosoh Corporation)
Sample concentration: diluted with tetrahydrofuran to 1.0 mg / cm ³ Mobile phase solvent: tetrahydrofuran Flow rate: 1.0 cm ³ / min Column temperature: 40 ° C.
<Gel fraction>
About 0.1 g (collected weight) of the pressure-sensitive adhesive composition after aging at 23 ° C. for 7 days was collected in a sampling bottle, added with 30 cc of ethyl acetate and shaken for 4 hours. The mixture was filtered through a metal mesh, the residue on the metal mesh was dried at 100 ° C. for 2 hours, the dry weight was measured, and the following formula was obtained.

＜ヘイズ＞
得られた粘着シートの片面の剥離処理されたポリエチレンテレフタレートフィルム（以下、ＰＥＴフィルムともいう。）を剥がして、厚み２５μｍポリエチレンテレフタレートフィルムを貼り合わせ、５０mm×５０mmのサイズに裁断した。次いで、もう一方の剥離フィルムを剥がして、厚み２mmポリカーボネート（PC）板に貼り合わせ、５０℃、５ａｔｍのオートクレーブで２分間処理した後、１時間静置して試験片を作成した。

<Haze>
The polyethylene terephthalate film (hereinafter also referred to as PET film) on which one side of the obtained pressure-sensitive adhesive sheet was peeled off was peeled off, and a 25 μm-thick polyethylene terephthalate film was bonded and cut into a size of 50 mm × 50 mm. Next, the other release film was peeled off, bonded to a 2 mm thick polycarbonate (PC) plate, treated in an autoclave at 50 ° C. and 5 atm for 2 minutes, and then allowed to stand for 1 hour to prepare a test piece.

  After measuring the haze before the endurance test of the prepared test piece, it was left to stand in an environment of 60 ° C. and 90%, and in an environment of 85 ° C. and 85%, respectively, and an endurance test was performed. Then, after leaving each test piece still at room temperature for 1 hour, the haze was measured and the difference with the haze before an endurance test was calculated | required.

For the measurement of haze, MH-150 (manufactured by Murakami Color Research Laboratory Co., Ltd.) was used.
<Foaming>
The peeled PET film on one side of the obtained pressure-sensitive adhesive sheet was peeled off, and a 25 μm thick polyethylene terephthalate film on which ITO was vapor-deposited was bonded and cut into a size of 50 mm × 50 mm. Next, the other release film was peeled off, bonded to a 2 mm thick polycarbonate (PC) plate, treated in an autoclave at 50 ° C. and 5 atm for 2 minutes, and then allowed to stand for 1 hour to prepare a test piece.

  The prepared test pieces were allowed to stand for 500 hours in an environment of 60 ° C. and 90%, 85 ° C. and dry environment, and 85 ° C. and 85% environment, respectively. Then, after leaving each test piece still at room temperature for 1 hour, the degree of foaming was confirmed visually and evaluated according to the following criteria.

Evaluation criteria are as follows (Evaluation) (Contents)
A: No bubbles can be visually confirmed in the pressure-sensitive adhesive layer.

○: Slight bubbles can be visually confirmed.
Δ: Although practical, bubbles can be clearly observed visually.
X: Large bubbles can be confirmed. Further, the pressure-sensitive adhesive layer floats from the base material or the adherend.
<ITO resistance change rate>
A test piece was prepared in the same manner as the foam test, and the resistance value of the test piece was measured in advance. Subsequently, the resistance value of the test piece left to stand at 85 ° C. and 85% for 500 hours was measured, and the rate of change of the resistance value with respect to the value measured in advance was obtained.

The resistance value was measured using a tester (manufactured by Sanwa Denki Keiki Co., Ltd., Digital Multimeter PC510).
<Step following capability>
The peeled PET film on one side of the obtained pressure-sensitive adhesive sheet was peeled off, a 25 μm PET film was bonded, and cut into 50 mm × 50 mm to prepare a test piece.

  Next, the PET film cut to 25 mm × 25 mm is placed on the glass plate, the peeled PET film on the other side of the prepared test piece is peeled off, and the PET film on the glass plate is pasted so as to cover the entire surface. The sample was allowed to stand in an 80 ° C. environment for 500 hours and then allowed to stand at room temperature for 1 hour, and the appearance of the step portion was visually observed.

(Evaluation) (Content)
A: Bubbles cannot be visually confirmed at the stepped portion.
○: A slight amount of air bubbles can be confirmed at the stepped portion by visual attachment.
Yes.
X: Large bubbles can be confirmed at the stepped portion. Further, the pressure-sensitive adhesive layer floats from the base material or the adherend.
<Adhesive strength to ITO>
The peeled PET film on one side of the obtained pressure-sensitive adhesive sheet was peeled off, bonded to a 25 μm PET film, and cut into a width of 25 mm to prepare a test piece.

Next, the other peelable PET film of the test piece was peeled off and bonded to a PET film on which ITO was deposited.
The test piece was peeled in the direction of 180 ° at a speed of 300 mm / min, and the peel strength was measured.
<Adhesive strength against HC>
The peeled PET film on one side of the obtained pressure-sensitive adhesive sheet was peeled off, a 25 μm PET film was bonded, and cut into a width of 25 mm to prepare a test piece.

Next, the other peelable PET film of the test piece was peeled off and bonded to a silicone hard coat PET film.
The test piece was peeled in the direction of 180 ° at a speed of 300 mm / min, and the peel strength was measured.
[Production Example 1]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 34 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Parts, 2 parts by weight of acrylamide (AM), 100 parts by weight of ethyl acetate (EtAc) and 20 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 1 having a weight average molecular weight of 300,000.
[Production Example 2]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 34 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Parts, 2 parts by weight of dimethylaminoethyl acrylate (DMAEA), 100 parts by weight of ethyl acetate (EtAc) and 20 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 2 having a weight average molecular weight of 300,000.
[Production Example 3]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 34 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Parts, 2 parts by weight of n-vinylpyrrolidone (n-VP), 100 parts by weight of ethyl acetate (EtAc) and 20 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 3 having a weight average molecular weight of 300,000.
[Production Example 4]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 34 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Parts, 2 parts by weight of acryloylmorpholine (ACMO), 100 parts by weight of ethyl acetate (EtAc) and 20 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 4 having a weight average molecular weight of 300,000.
[Production Example 5]
In a reaction apparatus equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxydiethylene glycol acrylate (ECA), 34 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Parts, 2 parts by weight of acrylamide (AM), 100 parts by weight of ethyl acetate (EtAc) and 20 parts by weight of methyl ethyl ketone (MEK) were added, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 5 having a weight average molecular weight of 300,000.
[Production Example 6]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 36 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Parts, 100 parts by weight of ethyl acetate (EtAc) and 20 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 6 having a weight average molecular weight of 300,000.
[Production Example 7]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 34 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Part, 2 parts by weight of acrylamide (AM) and 150 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 7 having a weight average molecular weight of 100,000.
[Production Example 8]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 20 parts by weight of methoxyethyl acrylate (MEA), 74 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Parts, 2 parts by weight of acrylamide (AM), 100 parts by weight of ethyl acetate (EtAc) and 20 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 8 having a weight average molecular weight of 300,000.
[Production Example 9]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 20 parts by weight of methoxyethyl acrylate (MEA), 74 parts by weight of 2-ethylhexyl acrylate (2EHA), 2-hydroxyethyl acrylate (2-HEA) 4 parts by weight, 2 parts by weight of acrylamide (AM), 110 parts by weight of ethyl acetate (EtAc) and 10 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 9 having a weight average molecular weight of 380,000.
[Production Example 10]
In a reaction apparatus equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 37 parts by weight of butyl acrylate (BA), 1 part by weight of 2-hydroxyethyl acrylate (2-HEA) Parts, 2 parts by weight of acrylamide (AM), 100 parts by weight of ethyl acetate (EtAc) and 20 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 10 having a weight average molecular weight of 300,000.
[Production Example 11]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 35 parts by weight of butyl acrylate (BA), 3 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Part, 2 parts by weight of acrylamide (AM), 100 parts by weight of ethyl acetate (EtAc) and 20 parts by weight of methyl ethyl ketone (MEK) were heated to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 11 having a weight average molecular weight of 300,000.
[Production Example 12]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen inlet tube, 60 parts by weight of methoxyethyl acrylate (MEA), 29 parts by weight of butyl acrylate (BA), 9 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Part, 2 parts by weight of acrylamide (AM), 100 parts by weight of ethyl acetate (EtAc) and 20 parts by weight of methyl ethyl ketone (MEK) were heated to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 12 having a weight average molecular weight of 300,000.
[Production Example 13]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 33 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Parts, 2 parts by weight of acrylamide (AM), 1 part by weight of acrylic acid (AA), 100 parts by weight of ethyl acetate (EtAc), and 20 parts by weight of methyl ethyl ketone (MEK) were heated to 70 ° C. while introducing nitrogen gas. .

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 13 having a weight average molecular weight of 300,000.
[Production Example 14]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 34 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Parts, 2 parts by weight of acrylamide (AM) and 120 parts by weight of ethyl acetate (EtAc) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 14 having a weight average molecular weight of 500,000.
[Production Example 15]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 63 parts by weight of butyl acrylate (BA), 31 parts by weight of methyl acrylate (MA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Then, 2 parts by weight of acrylamide (AM), 105 parts by weight of ethyl acetate (EtAc) and 15 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 15 having a weight average molecular weight of 360,000.
[Production Example 16]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 60 parts by weight of methoxyethyl acrylate (MEA), 34 parts by weight of butyl acrylate (BA), 4 parts by weight of 2-hydroxyethyl acrylate (2-HEA) Part, 2 parts by weight of acrylamide (AM) and 180 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain an acrylic polymer 16 having a weight average molecular weight of 30,000.
[Production Example 18 Production of Low Molecular Weight Material]
A reactor equipped with a stirrer, reflux condenser, thermometer and nitrogen inlet tube was charged with 95 parts by weight of methyl methacrylate (MMA), 5 parts by weight of dimethylaminoethyl acrylate (DMAEA) and 150 parts by weight of toluene, and nitrogen gas was introduced. The temperature was raised to 85 ° C.

Subsequently, 0.2 part by weight of azobisisobutyronitrile (AIBN) was added, and a polymerization reaction was performed at 70 ° C. for 5 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction mixture was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a low molecular weight product having a weight average molecular weight of 10,000.
[Example 1]
To 100 parts by weight of the acrylic polymer 1 obtained in Production Example 1, 0.3 part by weight of trimethylolpropane adduct type hexamethylene diisocyanate was mixed as a crosslinking agent to obtain an adhesive composition.

  The obtained pressure-sensitive adhesive composition was coated on a peeled polyethylene terephthalate (PET) film so that the thickness after drying was 50 μm, dried at 80 ° C. for 2 minutes to remove the solvent, and pressure-sensitive adhesive. A layer was formed. The peeled PET film was bonded to the surface of the pressure-sensitive adhesive layer that was in contact with the PET film, and aged for 7 days in an environment of 23 ° C. and 65% to obtain a pressure-sensitive adhesive sheet.

[Example 2]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of acrylic polymer 2 was used instead of 100 parts by weight of acrylic polymer 1.
[Example 3]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of acrylic polymer 3 was used instead of 100 parts by weight of acrylic polymer 1.

[Example 4]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of acrylic polymer 4 was used instead of 100 parts by weight of acrylic polymer 1.
[Example 5]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 0.3 parts by weight of isocyanurate of hexamethylene diisocyanate was used instead of 0.3 parts by weight of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent.

[Example 6]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 0.3 parts by weight of biuret type hexamethylene diisocyanate was used instead of 0.3 parts by weight of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent.
[Example 7]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the acrylic polymer 5 was used instead of the acrylic polymer 1.

[Example 8]
To 100 parts by weight of the acrylic polymer 6 obtained in Production Example 6, 5 parts by weight of the low molecular weight product obtained in Production Example 18 and 0.3 part by weight of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent were mixed. A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition obtained above was used.

[Example 9]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the acrylic polymer 7 was used instead of the acrylic polymer 1.
[Example 10]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the acrylic polymer 8 was used instead of the acrylic polymer 1.

[Example 11]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the acrylic polymer 9 was used instead of the acrylic polymer 1.
[Example 12]
Except for using acrylic polymer 10 instead of acrylic polymer 1 and changing the amount of trimethylolpropane adduct type hexamethylene diisocyanate as a cross-linking agent to 100 parts by weight of acrylic polymer 10 to 1 part by weight, A pressure-sensitive adhesive sheet was obtained in the same manner as Example 1.

[Example 13]
Acrylic polymer 11 was used in place of acrylic polymer 1, and the amount of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent was changed to 0.5 parts by weight with respect to 100 parts by weight of acrylic polymer 11 Obtained the adhesive sheet like Example 1. FIG.

[Example 14]
Acrylic polymer 12 was used in place of acrylic polymer 1, and the amount of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent was changed to 0.1 parts by weight with respect to 100 parts by weight of acrylic polymer 12 Obtained the adhesive sheet like Example 1. FIG.

[Comparative Example 1]
Obtained by mixing 0.4 parts by weight of trimethylolpropane adduct type xylylene diisocyanate instead of 0.3 parts by weight of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent with 100 parts by weight of acrylic polymer 1 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that the pressure-sensitive adhesive composition was used .

[Comparative Example 2]
Adhesive obtained by mixing 0.3 part by weight of biuret-type xylylene diisocyanate instead of 0.3 part by weight of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent with 100 parts by weight of acrylic polymer 1 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the composition was used .

[Comparative Example 3]
Obtained by mixing 0.3 parts by weight of trimethylolpropane adduct type tolylene diisocyanate instead of 0.3 parts by weight of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent with 100 parts by weight of acrylic polymer 1 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that the pressure-sensitive adhesive composition was used .

[Comparative Example 4]
Obtained by mixing 0.3 parts by weight of trimethylolpropane adduct type isophorone diisocyanate instead of 0.3 parts by weight of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent with respect to 100 parts by weight of acrylic polymer 1 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition was used .

[Comparative Example 5]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the acrylic polymer 13 was used instead of the acrylic polymer 1.
[Comparative Example 6]
Acrylic polymer 5 is used instead of acrylic polymer 1, and trimethylolpropane adduct type instead of 0.3 part by weight of trimethylolpropane adduct type hexamethylene diisocyanate as a cross-linking agent with respect to 100 parts by weight of acrylic polymer 14 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive composition obtained by mixing 0.3 part by weight of xylylene diisocyanate was used .

[Comparative Example 7]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the acrylic polymer 14 was used instead of the acrylic polymer 1.
[Comparative Example 8]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the amount of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent was changed to 0.05 parts by weight with respect to 100 parts by weight of the acrylic polymer 1. .

[Comparative Example 9]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that the amount of trimethylolpropane adduct type hexamethylene diisocyanate as a crosslinking agent was changed to 10 parts by weight with respect to 100 parts by weight of the acrylic polymer 1.
[Comparative Example 10]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the acrylic polymer 15 was used instead of the acrylic polymer 1.
[Comparative Example 11]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the acrylic polymer 16 was used instead of the acrylic polymer 1.

表中の略号は、以下の通りである。
MEA：メトキシエチルアクリレート
ECA：メトキシジエチレングリコールアクリレート
BA：ブチルアクリレート
2EHA：2-エチルヘキシルアクリレート
MA：メチルアクリレート
2-HEA：2-ヒドロキシエチルアクリレート
AM：アクリルアミド
DMAEA：ジメチルアミノエチルアクリレート
n-VP：n-ビニルピロリドン
ACMO：アクリロイルモルホリン
AA：アクリル酸
HDI：ヘキサメチレンジイソシアネート
XDI：キシリレンジイソシアネート
TDI：トリレンジイソシアネート
IPDI：イソホロンジイソシアネート

Abbreviations in the table are as follows.
MEA: Methoxyethyl acrylate
ECA: Methoxydiethylene glycol acrylate
BA: Butyl acrylate
2EHA: 2-ethylhexyl acrylate
MA: Methyl acrylate
2-HEA: 2-hydroxyethyl acrylate
AM: Acrylamide
DMAEA: Dimethylaminoethyl acrylate
n-VP: n-Vinylpyrrolidone
ACMO: acryloylmorpholine
AA: Acrylic acid
HDI: Hexamethylene diisocyanate
XDI: xylylene diisocyanate
TDI: Tolylene diisocyanate
IPDI: Isophorone diisocyanate

10-1 ... resistive film type touch panel unit 10-2 ... capacitive touch panel unit 11-1 ... upper laminate 13-1 ... lower laminate 15-1 ... upper part Laminate 15-2 ... Lower laminate 21-1 ... Surface support 21-2 ... Deep surface support 23-1 ... Adhesive layer 23-2 ... Adhesive layer 25 -1 ... Upper electrode support 25-2 ... Lower electrode support 27-1 ... Transparent conductive film 27-2 ... Transparent conductive film 30 ... Bonding agent 32 ... Spacer 34 ... Gap 51-1 ... Surface support 51-2 ... Surface support 53-1 ... Adhesive layer 57-1 ... Transparent conductive film 57-2 ... Transparent conductive film 60 ... Center support 62 ... Frame printing part 64 ... Gap 66 ... Bubble 68 ... Bubble

Claims (27)

The following components (a-1) , (a-2) and (a-3)
(a-1) Alkoxy (meth) acrylate 20 to 99.1 % by weight
(a-2) 0.8 to 9 % by weight of monomer having a crosslinkable functional group
(a-3) A nitrogen-containing monomer having a weight average molecular weight of 50,000 having substantially no acidic group obtained by copolymerization of a monomer containing 5% by weight or less (with all monomers being 100% by weight). It contains 0.1 to 5 parts by weight of an aliphatic isocyanate-based crosslinking agent (B) with respect to 100 parts by weight of the acrylic polymer (A) that is less than 400,000 and 100 parts by weight of the acrylic polymer (A). Characteristic adhesive.   The pressure-sensitive adhesive according to claim 1, wherein the aliphatic isocyanate-based crosslinking agent (B) has three or more isocyanate groups in one molecule.   The pressure-sensitive adhesive according to claim 1 or 2, wherein the monomer (a-2) having a crosslinkable functional group forming the acrylic polymer (A) is a hydroxyl group-containing monomer. The (a-3) a nitrogen-containing monomer, claims, characterized in that at least one of amino group-containing monomers, amide group-containing monomers, from the group consisting of nitrogenous heterocyclic containing monomer and a cyano group-containing monomer selected The adhesive as described in any one of 1-3 . The pressure-sensitive adhesive according to any one of claims 1 to 4 , wherein the pressure-sensitive adhesive is a pressure-sensitive adhesive for a capacitive touch panel in direct contact with a metal or a metal oxide. The pressure-sensitive adhesive according to any one of claims 1 to 4 , wherein the pressure-sensitive adhesive is a pressure-sensitive adhesive for a capacitive touch panel in direct contact with a hard coat layer on a surface support of the touch panel. Agent. The pressure-sensitive adhesive according to claim 6 , wherein the hard coat layer is of a silicone type. The following components (a-1) , (a-2) and (a-3)
(a-1) Alkoxy (meth) acrylate 20 to 99.1 % by weight
(a-2) 0.8 to 9 % by weight of monomer having a crosslinkable functional group
(a-3) A nitrogen-containing monomer having a weight average molecular weight of 50,000 having substantially no acidic group obtained by copolymerization of a monomer containing 5% by weight or less (with all monomers being 100% by weight). The pressure-sensitive adhesive containing an acrylic polymer (A) having a molecular weight of less than 400,000 and 0.1 to 5 parts by weight of an aliphatic isocyanate crosslinking agent (B) with respect to 100 parts by weight of the acrylic polymer (A). Formed from
A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer having a gel fraction of 40 to 80% by weight and a thickness of 10 to 1000 μm. The pressure-sensitive adhesive sheet according to claim 8 , wherein the aliphatic isocyanate-based crosslinking agent (B) has three or more isocyanate groups in one molecule. The pressure-sensitive adhesive sheet according to claim 8 or 9 , wherein the monomer (a-2) having a crosslinkable functional group forming the acrylic polymer (A) is a hydroxyl group-containing monomer. The (a-3) a nitrogen-containing monomer, claims, characterized in that at least one of amino group-containing monomers, amide group-containing monomers, from the group consisting of nitrogenous heterocyclic containing monomer and a cyano group-containing monomer selected The adhesive sheet as described in any one of 8-10 . The pressure-sensitive adhesive forming the pressure-sensitive adhesive sheet is a pressure-sensitive adhesive for a capacitive touch panel that is in direct contact with a metal or metal oxide, The pressure-sensitive adhesive according to any one of claims 8 to 11. Sheet. Pressure-sensitive adhesive forming the pressure-sensitive adhesive sheet, any one of claims 8 to 11, characterized in that an adhesive agent for a capacitive touch panel in direct contact with the hard coat layer on the surface support of the touch panel The pressure-sensitive adhesive sheet according to item. The pressure-sensitive adhesive sheet according to claim 13 , wherein the hard coat layer is of a silicone type. The pressure-sensitive adhesive sheet according to any one of claims 8 to 14 , wherein a cover film subjected to a peeling treatment is disposed on at least one surface of the pressure-sensitive adhesive sheet. The following components (a-1) and (a-2)
(a-1) Alkoxy (meth) acrylate 20 to 99.9% by weight
(a-2) Monomer having a crosslinkable functional group 0.1 to 10% by weight
An acrylic polymer (A) having a weight average molecular weight of not less than 50,000 and less than 400,000, which is substantially free of acidic groups, obtained by copolymerization of a monomer containing all monomers (100% by weight of all monomers); It is formed from a pressure-sensitive adhesive containing 0.1 to 5 parts by weight of an aliphatic isocyanate-based crosslinking agent (B) with respect to 100 parts by weight of the polymer-based polymer (A).
In gel fraction is 40 to 80 wt%, on one surface of the pressure-sensitive adhesive sheet that have a pressure-sensitive adhesive layer with a thickness in the range of 10 to 1000 [mu] m, the frame to the edge of the surface facing the PSA sheet A printed surface support is stuck, and a transparent conductive film made of a metal or metal oxide or a metal or metal oxide with an electrode support is stuck to the other surface of the pressure-sensitive adhesive sheet The laminated body for touch panels. The laminate for a touch panel according to claim 16 , wherein the laminate for a touch panel is a member forming a capacitive touch panel. The thickness of the said frame printing exists in the range of 10-50 micrometers, The laminated body for touchscreens of Claim 16 or 17 characterized by the above-mentioned. The transparent conductive film, ITO, ATO, or a wiring pattern using the tin oxide, any one of claims 16-18, characterized in that the adhesive sheet is in direct contact with the wiring pattern The laminated body for touchscreens as described in 2. Touch panel laminate according to any one of claims 16 to 19, the thickness of the surface support is characterized in that in the range of 25～2000Myuemu. Touch panel laminate of any one of claims 16-20, wherein the thickness of the transparent conductive film is within the range of 10 to 100 nm. The aliphatic isocyanate crosslinking agent (B), the touch panel laminate according to any of claims 16-21 characterized by having three or more isocyanate groups in one molecule. The laminate for a touch panel according to any one of claims 16 to 22 , wherein the monomer (a-2) having a crosslinkable functional group forming the acrylic polymer (A) is a hydroxyl group-containing monomer. . 24. The acrylic polymer (A) is obtained by copolymerizing a monomer further containing (a-3) 5% by weight or less of a nitrogen-containing monomer, according to any one of claims 16 to 23 . Laminate for touch panel. The (a-3) nitrogen-containing monomer is at least one selected from the group consisting of an amino group-containing monomer, an amide group-containing monomer, a nitrogen-based heterocyclic ring-containing monomer, and a cyano group-containing monomer. 25. A laminate for a touch panel according to 24 . The laminate for a touch panel according to any one of claims 16 to 25 , wherein the pressure-sensitive adhesive sheet is in direct contact with a hard coat layer on a surface support of the touch panel. 27. The laminate for a touch panel according to claim 26 , wherein the hard coat layer is silicone-based.

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