JP2013047295A - Adhesive agent, adhesive sheet and laminate for touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive agent which is excellent in heat resistance and wet heat resistance stability, and does not have corrosiveness to a metal or a metal oxide, and to provide an adhesive sheet and a laminate for touch panels, which are obtained by using the adhesive sheet.SOLUTION: The adhesive agent contains: 100 pts.wt. of a (meth)acrylic polymer (A); 1-30 pts.wt. of at least one type (B) selected from the group comprising nonionic surfactants and polyalkylene glycols; and 0.05-10 pts.wt. of an isocyanate-based cross-linking agent (C). The (meth)acrylic polymer (A) is obtained by copolymerizing a monomer (on condition that the total of monomers is 100 wt.%) including: (a-1) 20-99.4 wt.% of alkoxyalkyl (meth)acrylate; (a-2) 0.5-10 wt.% of a monomer having a cross-linking functional group; and (a-3) 0.1-5 wt.% of a hydrogen bonding monomer; wherein the (meth)acrylic polymer (A) has no acidic group substantially and has the weight-average molecular weight of ≥50,000 and <400,000.

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 panel unit is roughly classified into a contact film type touch panel and a capacitance type touch panel, both of which are laminates of various materials, and an acrylic adhesive is mainly used for bonding. . Since the touch panel unit is disposed on the outermost surface of the screen, characteristics such as high heat resistance and moist 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 outer gas 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 of PC materials, there is a characteristic that outer gas is generated under high temperature conditions, foaming occurs under heat resistant conditions because it is easy to pass moisture, and whitening phenomenon of the adhesive layer due to moisture inflow under humid heat conditions There is also a problem that it is difficult to suppress this. In addition, since the IMD has a step on the order of submicrons, there is also a problem that the pressure-sensitive adhesive cannot follow the step and bubbles are involved.

  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 made of a metal or metal oxide such as indium tin oxide (ITO) or antimony tin oxide (ATO), causing corrosion due to contact with acid, and its resistance value changes. Means for securing characteristics such as heat resistance and heat-and-moisture resistance using an acid component conventionally used cannot be used.

  Regarding the corrosion of transparent electrodes made of metals such as ITO and ATO or metal oxides, Patent Document 1 (Japanese Patent Application No. 2010-77287) discloses a polymer mainly composed of alkoxyalkyl acrylate. In this patent document 1, it is disclosed that an alkoxyalkyl acrylate polymer having a weight average molecular weight of 400,000 to 1,600,000 and not using a carboxyl group-containing monomer is disclosed.

  Thus, by using 400,000 to 1.6 million alkoxyalkyl acrylate polymers without using carboxyl group-containing monomers, the corrosion of transparent electrodes made of metals or metal oxides such as ITO and ATO 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 polymer disclosed in Patent Document 1 has a very large weight average molecular weight of 400,000 to 1,600,000, the polymer solution increases when the solid content increases when this is dissolved in a solvent to prepare a coating solution. The viscosity is too high. In touch panel applications, particularly capacitive touch panels, it is necessary to form a pressure-sensitive adhesive layer with a film thickness in order to bond the surface support to a conductive film such as ITO or ATO, but the weight average molecular weight is 400,000 Since a coating liquid with a high solid content cannot be prepared by using an alkoxyalkyl acrylate polymer of ˜1.6 million, it is necessary to prepare a coating liquid with a low solid content and apply repeatedly. However, it is difficult to form a pressure-sensitive adhesive layer having a thickness required for coating.

JP 2010-77287 A

  The present invention is a pressure-sensitive adhesive for a touch panel having a conductive film made of a metal or a metal oxide, has excellent heat resistance and moist heat resistance, can be suppressed from whitening and foaming, and is not corrosive to a metal or metal oxide. It aims at providing the adhesive, the adhesive sheet, and the laminated body for touchscreens using the same.

Furthermore, it aims at providing the adhesive and adhesive sheet which do not have a problem also in bonding including level | step differences, such as frame printing.
Another object of the present invention is to provide a pressure-sensitive adhesive or pressure-sensitive adhesive sheet with good workability.

The present invention relates to the following [1] to [21], for example.
[1] Components (a-1), (a-2) and (a-3) shown below
(A-1) 20-99.4% by weight of at least one selected from the group consisting of alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol mono (meth) acrylates,
(A-2) 0.5 to 10% by weight of a monomer having a crosslinkable functional group,
(A-3) Hydrogen bonding monomer 0.1 to 5% by weight
A (meth) acrylic polymer (A) having a weight average molecular weight of substantially 50,000 or more and less than 400,000, which is substantially free of acidic groups obtained by copolymerization of monomers containing 100% by weight of all monomers (including all monomers) ,
With respect to 100 parts by weight of the (meth) acrylic polymer (A), at least one selected from the group consisting of a nonionic surfactant and a polyalkylene glycol (B) 1 to 30 parts by weight, an isocyanate crosslinking agent ( C) A pressure-sensitive adhesive containing 0.05 to 10 parts by weight.

[2] The pressure-sensitive adhesive according to [1], wherein the monomer having a crosslinkable functional group is a hydroxyl group-containing monomer.
[3] The hydrogen bonding 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 [1] Or the adhesive as described in [2].

[4] The pressure-sensitive adhesive according to any one of [1] to [3], 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.
[5] The pressure-sensitive adhesive according to any one of [1] to [4], wherein the (meth) acrylic polymer (A) is produced by solution polymerization.

[6] Components (a-1), (a-2) and (a-3) shown below
(A-1) 20-99.4% by weight of at least one selected from the group consisting of alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol mono (meth) acrylates,
(A-2) 0.5 to 10% by weight of a monomer having a crosslinkable functional group,
(A-3) Hydrogen bonding monomer 0.1 to 5% by weight
A (meth) acrylic polymer (A) having a weight average molecular weight of substantially 50,000 or more and less than 400,000, which is substantially free of acidic groups obtained by copolymerization of monomers containing 100% by weight of all monomers (including all monomers) ,
With respect to 100 parts by weight of the (meth) acrylic polymer (A), at least one selected from the group consisting of a nonionic surfactant and a polyalkylene glycol (B) 1 to 30 parts by weight, an isocyanate crosslinking agent ( C) A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer having a thickness in the range of 10 to 1000 μm formed from a pressure-sensitive adhesive containing 0.05 to 10 parts by weight.

[7] The pressure-sensitive adhesive sheet according to [6], wherein the monomer having a crosslinkable functional group is a hydroxyl group-containing monomer.
[8] The hydrogen bonding monomer is at least one monomer 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. 6] or the pressure-sensitive adhesive sheet according to [7].

[9] The pressure-sensitive adhesive sheet according to any one of [6] to [8], wherein the (meth) acrylic polymer (A) is produced by solution polymerization.
[10] Any one of [6] to [9], 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.

  [11] The pressure-sensitive adhesive sheet according to any one of [6] to [10], wherein a cover film subjected to a release treatment is disposed on at least one surface of the pressure-sensitive adhesive sheet.

[12] Components (a-1), (a-2) and (a-3) shown below
(A-1) 20-99.4% by weight of at least one selected from the group consisting of alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol mono (meth) acrylates,
(A-2) 0.5 to 10% by weight of a monomer having a crosslinkable functional group,
(A-3) Hydrogen bonding monomer 0.1 to 5% by weight
A (meth) acrylic polymer (A) having a weight average molecular weight of substantially 50,000 or more and less than 400,000, which is substantially free of acidic groups obtained by copolymerization of monomers containing 100% by weight of all monomers (including all monomers) ,
With respect to 100 parts by weight of the (meth) acrylic polymer (A), at least one selected from the group consisting of a nonionic surfactant and a polyalkylene glycol (B) 1 to 30 parts by weight, an isocyanate crosslinking agent ( C) A surface support is adhered to one surface of the pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive containing 0.05 to 10 parts by weight within a range of 10 to 1000 μm. And a transparent conductive film made of a metal, a metal oxide, a metal with an electrode support, or a metal oxide is attached to the other surface of the pressure-sensitive adhesive sheet.

[13] The touch panel laminate according to [12], wherein the touch panel laminate is a member forming a capacitive touch panel.
[14] The touch panel laminate according to [12] or [13], wherein frame printing is performed on an edge of a surface of the surface support that faces the pressure-sensitive adhesive layer.

[15] The touch panel laminate as described in [14], wherein the thickness of the frame printing is in the range of 10 to 50 μm.
[16] The transparent electrode film is a wiring pattern using ITO and / or ATO as a metal oxide, and the adhesive sheet is in direct contact with the wiring pattern [12] to [15] ] The laminated body for touchscreens as described in any one of.

[17] The laminate for a touch panel according to any one of [12] to [16], wherein the surface support has a thickness in the range of 25 to 2000 μm.
[18] The laminate for a touch panel according to any one of [12] to [17], wherein the transparent conductive film has a thickness in the range of 10 to 100 nm.

[19] The laminate for a touch panel according to any one of [12] to [18], wherein the monomer having a crosslinkable functional group is a hydroxyl group-containing monomer.
[20] The hydrogen bonding monomer is at least one monomer 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 laminated body for touchscreens as described in any one of 12]-[19].

  [21] The laminate for a touch panel according to any one of [12] to [20], wherein the (meth) acrylic polymer (A) is produced by solution polymerization.

Since the pressure-sensitive adhesive of the present invention does not substantially contain an acid component, deterioration due to corrosion of a metal or metal oxide such as ITO or ATO can be effectively suppressed.
Furthermore, since the pressure-sensitive adhesive of the present invention has a weight average molecular weight (Mw) of 50,000 or more and less than 40, the solid content can be kept at a high concentration in the solvent, and a sufficient thickness can be applied in one coating process. Can do. In addition, the pressure-sensitive adhesive becomes flexible and has excellent step following ability. Moreover, the pressure-sensitive adhesive of the present invention contains a nonionic surfactant and / or polyalkylene glycol, so that the heat-and-moisture whitening resistance and step following property of the pressure-sensitive adhesive are good.

  Since the cross-linked structure is formed by the isocyanate-based cross-linking agent, the pressure-sensitive adhesive of the present invention has high cohesive force and suppresses outgas generated from the adherend, so that it has excellent foam resistance and heat and moisture heat stability. And has very good form following ability.

  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 transparent conductive films made of metals such as ITO and ATO or metal oxides. 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 the following components (a-1), (a-2) and (a-3)
(A-1) 20-99.4% by weight of at least one selected from the group consisting of alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol mono (meth) acrylates,
(A-2) 0.5 to 10% by weight of a monomer having a crosslinkable functional group,
(A-3) Hydrogen bonding monomer 0.1 to 5% by weight
A (meth) acrylic polymer (A) having a weight average molecular weight of substantially 50,000 or more and less than 400,000, which is substantially free of acidic groups obtained by copolymerization of monomers containing 100% by weight of all monomers (including all monomers) ,
With respect to 100 parts by weight of the (meth) acrylic polymer (A), at least one selected from the group consisting of a nonionic surfactant and a polyalkylene glycol (B) 1 to 30 parts by weight, an isocyanate crosslinking agent ( C) 0.05 to 10 parts by weight.

  The (meth) acrylic polymer (A) used in the present invention is obtained by copolymerizing at least one (a-1) selected from the group consisting of alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol mono (meth) acrylates. ing.

  As at least one (a-1) selected from the group consisting of such alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol mono (meth) acrylates, from the viewpoint of suppression of whitening, the number of carbon atoms of the alkoxy moiety is Alkoxyalkyl (meth) acrylates having 1 to 2 carbon atoms and 1 to 4 carbon atoms in the alkyl portion are preferred, carbon numbers in the terminal alkoxy portion are 1 to 2, and the alkylene glycol is ethylene glycol and / or propylene glycol. And an alkoxypolyalkylene glycol mono (meth) acrylate having 1 to 3 alkylene glycol units is preferred, an alkoxyalkyl having 1 to 2 carbon atoms in the alkoxy moiety and 1 to 2 carbon atoms in the alkyl moiety (meta ) Acrylate is more preferred, Is the number of carbon atoms of the end alkoxy moiety is 1, the alkylene glycol is ethylene glycol, alkoxy polyalkylene glycol mono (meth) acrylate the number of alkylene glycol units is 2 to 3 being more preferred.

  Examples of the alkoxyalkyl (meth) acrylate and alkoxypolyalkylene glycol mono (meth) acrylate constituting the (meth) acrylic polymer (A) used here include 2-methoxymethyl (meth) acrylate, 2-methoxy Ethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, 4-methoxybutyl (meth) acrylate, ethoxymethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 4 -Ethoxybutyl (meth) acrylate, methoxydiethylene glycol mono (meth) acrylate, methoxydipropylene glycol mono (meth) acrylate, ethoxydiethylene glycol mono (meth) acrylate, methoxytriethylene glycol mono (meth) acrylate It can be mentioned ethoxy triethylene glycol mono (meth) acrylate. These can be used alone or in combination. Among these, from the viewpoint of suppressing whitening, it is preferable to use methoxyethyl (meth) acrylate and methoxydiethylene glycol mono (meth) acrylate.

  The (meth) acrylic polymer (A) used in the present invention comprises at least one (a-1) selected from the group consisting of the above alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol mono (meth) acrylates, It is obtained by copolymerizing monomers containing 20 to 99.4% by weight, preferably 50 to 98.9% by weight (total monomer being 100% by weight). In the (meth) acrylic polymer (A), the monomer charge ratio is equal to the copolymerization ratio. If the amount of alkoxyalkyl (meth) acrylate is more than the above range, sufficient crosslinking density cannot be achieved. On the other hand, if the amount is less than the above range, the effect of suppressing the precipitation of moisture during wet heat and preventing whitening of the pressure-sensitive adhesive layer is lowered.

In the (meth) acrylic polymer (A) used in the present invention, a monomer (a-2) having a crosslinkable functional group is copolymerized.
The monomer (a-2) having a crosslinkable functional group 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 more preferable. Examples of such a (meth) acrylate compound having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl ( Mention may be made of (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 from the viewpoint of reactivity with the isocyanate-based crosslinking agent (C). These (meth) acrylate compounds having a hydroxyl group can be used alone or in combination.

  The (meth) acrylic polymer (A) used in the present invention contains the monomer (a-2) having a crosslinkable functional group in the range of 0.5 to 10% by weight, preferably 1 to 9% by weight. Is obtained by copolymerizing a monomer (total monomer is 100% by weight).

  If the amount of the monomer having a crosslinkable functional group is less than the above range, the crosslinked structure by the isocyanate-based crosslinking agent may not be sufficiently formed. If the amount of the monomer having a crosslinkable functional group is more than the above range, the crosslink structure is dense. The step following ability may be deteriorated due to the excessive increase.

  The (meth) acrylic polymer (A) used in the present invention improves the cohesive strength of the pressure-sensitive adhesive, promotes crosslinking with an isocyanate-based crosslinking agent, and further contains a hydrogen bonding monomer (a-3). Polymerized. The hydrogen-bonding monomer is preferably a nitrogen-containing monomer, and the nitrogen-containing monomer includes 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. It is preferable to use it.

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.

  Among these, (meth) acrylamide, dimethylaminoethyl (meth) acrylate, vinylpyrrolidone, and (meth) acryloylmorpholine are preferable from the viewpoint of copolymerization with the monomer (a-1) and the monomer (a-2). .

  The (meth) acrylic polymer (A) includes such a hydrogen-bonding monomer (a-3) in a range of 0.1 to 5% by weight, preferably 0.1 to 4% by weight (100% by weight of all monomers). To be copolymerized. When the amount of the hydrogen bonding monomer is larger than the above range, the step following ability is deteriorated. When the amount is less than the above range, foaming due to outgas from the adherend cannot be suppressed.

  Furthermore, the (meth) acrylic polymer of the present invention is not limited to the above-mentioned alkoxyalkyl (meth) acrylate and a monomer having a crosslinkable functional group, but may be other acrylics within the range that does not impair the properties of the (meth) acrylic polymer. System monomers may be copolymerized.

  Here, examples of other monomers forming the (meth) acrylic polymer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, 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 ( Examples include alkyl (meth) acrylates such as (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undeca (meth) acrylate, and dideca (meth) acrylate. These alkyl (meth) acrylates can be used alone or in combination. Among these, it is preferable to use butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methyl (meth) acrylate, iso-butyl (meth) acrylate, and (meth) acrylic polymer (A) The alkyl (meth) acrylate is preferably copolymerized with a monomer containing 0 to 79.4% by weight, more preferably 0 to 48.9% by weight (with 100% by weight of all monomers).

  Furthermore, the (meth) acrylic polymer (A) used in the present invention can be copolymerized with other monomers within a range that does not impair 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 (meth) 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 sulfonyl group. In the present invention, the (meth) acrylic polymer (A) is not copolymerized with the acidic group-containing monomer as described above. Since the acid group-containing monomer is not copolymerized in this way, the (meth) acrylic polymer (A) of the present invention does not corrode even if it is in direct contact with the wiring made of metal or metal oxide. The pressure-sensitive adhesive of the present invention can be imparted with 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 200,000 to 380,000.
The pressure-sensitive adhesive of the present invention further contains at least one (B) selected from the group consisting of a nonionic surfactant and a polyalkylene glycol.

Since the component (B) has good compatibility with moisture, it is considered that the moisture that has penetrated into the pressure-sensitive adhesive is dispersed in the pressure-sensitive adhesive layer to suppress whitening of the pressure-sensitive adhesive.
Since the nonionic surfactant has both a hydrophilic group and a lipophilic group, the hydrophilic group has good compatibility with the component (a-1) having a hydrophilic group, and the lipophilic group has It is considered that compatibility with the component (a-2), the component (a-3), etc. is good, the compatibility with the adhesive is very good, and the problem of bleeding out does not occur. The reason why the nonionic surfactant is selected among the surfactants is that the ionic surfactant is poorly compatible with the pressure-sensitive adhesive and bleed-out or foaming occurs.

  Polyalkylene glycol is considered that the oxyalkylene unit has good compatibility with the hydrophilic group of the component (a-1), so that it has good compatibility with the pressure-sensitive adhesive and does not cause a bleed-out problem.

  Nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene myristyl ether, and polyoxyethylene octyldodecyl ether. And polyoxyalkylene derivatives such as polyoxyethylene distyrenated phenyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyalkylene alkyl ether, and sorbitan fatty acid esters.

  Examples of the polyalkylene glycol include those having 2 to 3 carbon atoms of alkylene of the oxyalkylene group and 2 to 3 units of oxyalkylene units, and polypropylene glycol and polyethylene glycol are preferable.

Such nonionic surfactants (B) and polyalkylene glycols can be used alone or in combination.
Among nonionic surfactants and polyalkylene glycols, nonionic surfactants are preferred, and polyoxyethylene alkyl ethers are more preferred from the viewpoint of better compatibility with acrylic polymers (A). Of these, polyoxyethylene lauryl ether is preferred.

The pressure-sensitive adhesive of the present invention further contains an isocyanate-based crosslinking agent (C).
Examples of the isocyanate-based crosslinking agent (C) used in the present invention include molecules such as tolylene diisocyanate, xylylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate. A compound having two or more isocyanate groups: a compound obtained by addition reaction with a polyhydric alcohol such as trimethylolpropane or pentaerythritol, an isocyanurate compound, a burette type compound, and a known polyether polyol or polyester polyol, Two or more isocyanates in the urethane prepolymer type molecule that has undergone addition reaction with acrylic polyol, polybutadiene polyol, polyisoprene, etc. Mention may be made of compounds having an nate group.

  Among these, xylylene diisocyanate and its trimethylolpropane adduct are preferable in that it can improve conformability to the adherend and reduce entrainment of bubbles during bonding, and can suppress outgassing at high temperatures, In addition, hexamethylene diisocyanate, its trimethylolpropane adduct, and isocyanurate are preferable because they can improve the followability of the step on the attachment surface and improve the heat-resistant foaming property.

Such isocyanate-based crosslinking agents (C) can be used alone or in combination.
Thus, by mix | blending isocyanate type crosslinking agent (C), the cohesion force of an adhesive improves and it can suppress the expansion | swelling of the outgas generated from the bubble and the to-be-adhered body which were slightly involved at the time of sticking.

  The (meth) acrylic polymer (A) 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 can be adjusted by adjusting reaction conditions such as the type of solvent used, the type and amount of polymerization initiator, the reaction time, and the reaction temperature according to known techniques.

  The pressure-sensitive adhesive of the present invention is selected from the group consisting of the above (meth) acrylic polymer (A) and 100 parts by weight of the (meth) acrylic polymer (A), a nonionic surfactant and a polyalkylene glycol. 1 to 30 parts by weight, preferably 2 to 20 parts by weight, and 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, more preferably 0.1 to 5 parts by weight of the isocyanate-based crosslinking agent (C). Is obtained by blending 0.1 to 1 part by weight, removing the solvent, and curing at a temperature of 0 to 50 ° C. for 1 to 10 days. When the component (B) is less than the above range, it is insufficient to suppress whitening, and when it is more than the above range, adhesiveness is lowered due to bleed out.

  In this way, by adding component (B) after the polymerization rather than the polymerization stage of (meth) acrylic polymer (A), excess water is not taken into the reaction system at the polymerization stage and the polymerization reaction is inhibited. Not.

  In the pressure-sensitive adhesive of the present invention, an antioxidant, a light stabilizer, a tackifier, a plasticizer, an antistatic agent, a crosslinking accelerator, a reworking agent and the like are further blended within a range that does not impair the effect of the pressure-sensitive adhesive of the present invention. You can also

  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. Coating containing at least one (B) selected from the group consisting of (meth) acrylic polymer (A), nonionic surfactant and polyalkylene glycol used in the present invention, and an isocyanate crosslinking agent (C) in a solvent Since the solution has a low weight average molecular weight (Mw) of the (meth) acrylic polymer (A), the concentration of non-volatile components can be easily adjusted to a solvent such as ethyl acetate, methyl ethyl ketone, acetone, and 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 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 usually 50 to 80%, preferably 60 to 70%. In the present invention, the gel fraction is determined as follows.
About 0.1 g of the adhesive layer sample after aging at 23 ° C for 7 days was collected in a sample bottle, added with 30 cc of ethyl acetate, shaken for 4 hours, and then filtered the contents of this sample bottle through a 200 mesh stainless steel wire mesh. Then, the residue on the wire mesh is dried at 100 ° C. for 2 hours, the dry weight is measured, and the following formula is obtained.

このようにして得られた粘着シートは、各種部材に対して貼着することができるが、特に異種部材を貼り合わせるタッチパネル用部材の貼着に好適である。

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.

  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.
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 on which these layers are laminated 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. A pressure-sensitive adhesive layer 53-1 made of the pressure-sensitive adhesive of the present invention is disposed so as to bond the transparent conductive film 57-1 and the surface support 51-1.

  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.

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. Further, 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 a (meth) acrylic polymer (A) having a weight average molecular weight (Mw) of 50,000 or more and less than 400,000, these are cross-linked with an isocyanate cross-linking agent (C), so that excellent step followability is achieved. 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 has a specific composition and uses a (meth) acrylic polymer (A) having a weight average molecular weight (Mw) of 50,000 or more and less than 400,000, and these are isocyanate crosslinking agents (C). 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 water is suppressed even when water enters from the support layer, and therefore haze increase due to the whitening phenomenon is extremely generated. Hard to do.

  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 touch panel member of the present invention comprises a (meth) acrylic polymer (A) having a specific composition as an adhesive and having a weight average molecular weight of 50,000 to less than 400,000, a nonionic surfactant, and a polyalkylene glycol. The support and the transparent conductive film are adhered using an adhesive having at least one (B) selected from the group consisting of the above and an isocyanate-based crosslinking agent (C), and has excellent form following ability. In addition, no voids are formed in the frame printing portion formed at the edge, and both foaming due to entrainment and foaming due to outgas can be suppressed, and moisture that has penetrated into the adhesive layer is further dispersed. Therefore, the pressure-sensitive adhesive layer does not whiten and the haze value does not increase.

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.
Measurement and evaluation were performed by the following methods.
〔Measuring method〕

<Weight average molecular weight>
The weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of standard polystyrene were determined using gel permeation chromatography (GPC).
Measuring condition apparatus: HLC-8120 (manufactured by Tosoh Corporation)
Column: G7000HXL (manufactured by Tosoh Corporation)
GMHXL (manufactured by Tosoh Corporation)
G2500HXL (manufactured by Tosoh Corporation)
Sample concentration: 1.5 mg / ml (diluted with tetrahydrofuran)
Mobile phase solvent: Tetrahydrofuran Flow rate: 1.0 ml / min
Column temperature: 40 ° C

<Wet heat whitening (haze)>
An adhesive sheet cut to 50 mm × 60 mm was attached to a glass plate wiped with isopropyl alcohol, and autoclaved at 50 ° C. × 5 atm for 20 minutes. Next, after standing at room temperature for 1 hour, placing it in an environment of 85 ° C. and 85% RH for 500 hours, standing at 23 ° C. and 65% RH for 1 hour, and then haze meter HM-150 (Murakami Color Research Laboratory Co., Ltd.) )) And the haze was measured according to JIS K 7361 to evaluate the whitening of the pressure-sensitive adhesive layer.

<Foaming properties>
A pressure-sensitive adhesive sheet cut to 50 mm × 60 mm was attached to a polycarbonate plate wiped with isopropyl alcohol by peeling off the release sheet on one side, and autoclaved at 50 ° C. × 5 atm for 20 minutes. Next, after standing at room temperature for 1 hour, placing it in an environment of 85 ° C. and 85% RH for 500 hours and standing at 23 ° C. and 65% RH for 1 hour, the presence or absence of foaming of the adhesive layer was visually confirmed. . 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 corrosive>
The pressure-sensitive adhesive sheet was cut to 10 mm × 60 mm and attached to an ITO-deposited PET film cut to 10 mm × 100 mm, and autoclaved at 50 ° C. × 5 atm for 20 minutes. Next, after standing at room temperature for 1 hour, placing it in an environment of 60 ° C. and 90% RH for 500 hours, standing at 23 ° C. and 65% RH for 1 hour, then measuring the resistance value of the ITO deposited film and measuring it in advance The change rate of the resistance value with respect to the resistance value of the pressure-sensitive adhesive sheet that had not been subjected to the above treatment was determined. 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 pressure-sensitive adhesive sheet was peeled off, a 25 μm thick PET film was bonded to the entire surface, and cut into 50 mm × 50 mm to prepare test pieces.

Next, a 25 μm thick PET film cut to 25 mm × 25 mm is placed on a 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 covered to cover the entire surface. After standing at 80 ° C. for 500 hours, let it stand at room temperature for 1 hour, the appearance of the step between the glass plate and the PET film placed on the glass and covered with the test piece It was observed visually.
(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.
Δ: Bubbles can be visually confirmed at the stepped portion. Furthermore, after 24 hours of standing, bubbles can be clearly confirmed.
X: Large bubbles can be confirmed at the stepped portion. Further, the pressure-sensitive adhesive layer floats from the base material or the adherend.

<Coating property>
The pressure-sensitive adhesive composition was applied to a polyethylene terephthalate (PET) film having a thickness of 38 μm so that the thickness after drying was 200 μm, dried at 80 ° C. for 2 minutes, and then the surface of the coating film was visually confirmed.
○: The coating film surface is smooth and free of bubbles and roughness.
X: Bubbles and roughness are seen on the coating film surface.
[Production Example 1]
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), 31 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) 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, 25 parts by weight of methoxyethyl acrylate (MEA), 66 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 2 having a weight average molecular weight of 300,000.
[Production Example 3]
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), 31 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 3 having a weight average molecular weight of 300,000.
[Production Example 4]
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), 31 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) 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 methoxyethyl acrylate (MEA), 31 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 2 parts by weight of acroylmorpholine (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.

Next, 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 solution was diluted with ethyl acetate (EtAc), adjusted to a solid content concentration of 30%, and (meth) acrylic polymer 5 having a weight average molecular weight of 300,000 was obtained.
[Production Example 6]
A reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube was charged with 25 parts by weight of methoxyethyl acrylate (MEA), 67.5 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2- HEA), 7 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) 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, 25 parts by weight of methoxyethyl acrylate (MEA), 64 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 4 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 7 having a weight average molecular weight of 300,000.
[Production Example 8]
In a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube, 90 parts by weight of methoxyethyl acrylate (MEA), 1 part by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 8 having a weight average molecular weight of 300,000.
[Production Example 9]
A reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen introduction tube was charged with 60 parts by weight of methoxyethyl acrylate (MEA), 37.5 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2- HEA), 0.5 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 9 having a weight average molecular weight of 300,000.
[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), 28 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 10 parts by weight, 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) 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, 10 parts by weight of methoxyethyl acrylate (MEA), 81 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 11 having a weight average molecular weight of 300,000.
[Production Example 12]
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), 33 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 12 having a weight average molecular weight of 300,000.
[Production Example 13]
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), 26 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 7 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) 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), 38 parts by weight of n-butyl acrylate (BA), 2 parts by weight of acrylamide (AM), ethyl acetate 100 parts by weight of (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 8 hours in a nitrogen atmosphere.
After completion of the reaction, the reaction solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 14 having a weight average molecular weight of 300,000.
[Production Example 15]
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), 27 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 11 parts by weight, 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.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 15 having a weight average molecular weight of 300,000.
[Production Example 16]
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), 30 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 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 charged and the temperature was raised to 70 ° C. while introducing nitrogen gas Warm up.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 16 having a weight average molecular weight of 300,000.
[Production Example 17]
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), 31 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 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.

Next, 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 solution was diluted with ethyl acetate (EtAc), adjusted to a solid content concentration of 30%, and (meth) acrylic polymer 17 having a weight average molecular weight of 500,000 was obtained.
[Production Example 18]
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), 31 parts by weight of n-butyl acrylate (BA), 2-hydroxyethyl acrylate (2-HEA) 7 parts by weight, 2 parts by weight of acrylamide (AM), 100 parts by weight of ethyl acetate (EtAc) and 180 parts by weight of methyl ethyl ketone (MEK) were charged, and the temperature was raised to 70 ° C. while introducing nitrogen gas.

Next, 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 solution was diluted with ethyl acetate (EtAc) and adjusted to a solid content concentration of 30% to obtain a (meth) acrylic polymer 18 having a weight average molecular weight of 30,000.
[Example 1]
Takenate D-110N (Mitsui Chemicals), which is 10 parts by weight of polyoxyethylene lauryl ether and trimethylolpropane adduct type xylylene diisocyanate as a crosslinking agent, with respect to 100 parts by weight of (meth) acrylic polymer 1 obtained in Production Example 1. 0.4 parts by weight (solid content) was mixed 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 is bonded to the surface of the adhesive layer that is in contact with the PET film, and aged for 7 days in an environment of 23 ° C. and 65% to give an adhesive sheet (adhesive layer thickness 50 μm). Obtained.
[Example 2]
As the pressure-sensitive adhesive composition, 1 part by weight of polyoxyethylene lauryl ether and trimethylolpropane adduct type xylylene diisocyanate takenate D- as a crosslinking agent with respect to 100 parts by weight of (meth) acrylic polymer 1 obtained in Production Example 1 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that a composition in which 0.4 part by weight (solid content) of 110N was mixed was used.
[Example 3]
As an adhesive composition, with respect to 100 parts by weight of (meth) acrylic polymer 1 obtained in Production Example 1, 30 parts by weight of polyoxyethylene lauryl ether and a trimethylolpropane adduct type xylylene diisocyanate takenate D- as a crosslinking agent A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that a composition in which 0.4 part by weight (solid content) of 110N was mixed was used.
[Example 4]
As a pressure-sensitive adhesive composition, 5 parts by weight of polyoxyethylene lauryl ether, 5 parts by weight of polypropylene glycol (PPG) and trimethylolpropane as a cross-linking agent with respect to 100 parts by weight of (meth) acrylic polymer 1 obtained in Production Example 1 An adhesive sheet was obtained in the same manner as in Example 1 except that a composition in which 0.6 parts by weight (solid content) of adduct-type xylylene diisocyanate takenate D-110N was mixed was used.
[Example 5]
As an adhesive composition, with respect to 100 parts by weight of (meth) acrylic polymer 1 obtained in Production Example 1, 10 parts by weight of polypropylene glycol (PPG) and trimethylolpropane adduct type xylylene diisocyanate takenate D- as a crosslinking agent A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that a composition in which 0.8 parts by weight (solid content) of 110N was mixed was used.
[Example 6]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of (meth) acrylic polymer 2 was used instead of 100 parts by weight of (meth) acrylic polymer 1.
[Example 7]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of (meth) acrylic polymer 3 was used instead of 100 parts by weight of (meth) acrylic polymer 1.
[Example 8]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of (meth) acrylic polymer 4 was used instead of 100 parts by weight of (meth) acrylic polymer 1.
[Example 9]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of (meth) acrylic polymer 5 was used instead of 100 parts by weight of (meth) acrylic polymer 1.
[Example 10]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of (meth) acrylic polymer 6 was used instead of 100 parts by weight of (meth) acrylic polymer 1.
[Example 11]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of (meth) acrylic polymer 7 was used instead of 100 parts by weight of (meth) acrylic polymer 1.
[Example 12]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of (meth) acrylic polymer 8 was used instead of 100 parts by weight of (meth) acrylic polymer 1.
[Example 13]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that 100 parts by weight of (meth) acrylic polymer 9 was used instead of 100 parts by weight of (meth) acrylic polymer 1.
[Example 14]
A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that 100 parts by weight of (meth) acrylic polymer 10 was used instead of 100 parts by weight of (meth) acrylic polymer 1.
[Comparative Example 1]
As a pressure-sensitive adhesive composition, 0.4 parts by weight (solid content) of trimethylolpropane adduct type xylylene diisocyanate takenate D-110N as a crosslinking agent with respect to 100 parts by weight of (meth) acrylic polymer 1 obtained in Production Example 1. The pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the composition in which) was mixed was used.
[Comparative Example 2]
As an adhesive composition, 100 parts by weight of the (meth) acrylic polymer 1 obtained in Production Example 1, 0.5 parts by weight of polyoxyethylene lauryl ether and a trimethylolpropane adduct type xylylene diisocyanate takenate as a crosslinking agent A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that a composition in which 0.4 part by weight (solid content) of D-110N was mixed was used.
[Comparative Example 3]
As an adhesive composition, 40 parts by weight of polyoxyethylene lauryl ether and trimethylolpropane adduct type xylylene diisocyanate takenate D- as a crosslinking agent with respect to 100 parts by weight of (meth) acrylic polymer 1 obtained in Production Example 1. A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that a composition in which 0.4 part by weight (solid content) of 110N was mixed was used.
[Comparative Example 4]
As an adhesive composition, 10 parts by weight of dodecylbenzenesulfonate and 100 parts by weight of a (meth) acrylic polymer 1 obtained in Production Example 1 and a trimethylolpropane adduct type xylylene diisocyanate takenate D- as a crosslinking agent A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that a composition in which 0.4 part by weight (solid content) of 110N was mixed was used.
[Comparative Example 5]
As an adhesive composition, with respect to 100 parts by weight of the (meth) acrylic polymer 1 obtained in Production Example 1, 10 parts by weight of lauryltrimethylammonium chloride and trimethylolpropane adduct type xylylene diisocyanate takenate D-110N as a crosslinking agent A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that a composition mixed with 0.4 parts by weight (solid content) was used.
[Comparative Example 6]
As a pressure-sensitive adhesive composition, 0.4 parts by weight of trimethylolpropane adduct type xylylene diisocyanate takenate D-110N (solid content) as a crosslinking agent with respect to 100 parts by weight of (meth) acrylic polymer 11 obtained in Production Example 11. The pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the composition in which) was mixed was used.
[Comparative Example 7]
As a pressure-sensitive adhesive composition, 0.4 parts by weight of trimethylolpropane adduct type xylylene diisocyanate takenate D-110N (solid content) as a crosslinking agent with respect to 100 parts by weight of the (meth) acrylic polymer 12 obtained in Production Example 12. The pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the composition in which) was mixed was used.
[Comparative Example 8]
As a pressure-sensitive adhesive composition, 0.4 parts by weight of trimethylolpropane adduct type xylylene diisocyanate takenate D-110N (solid content) as a crosslinking agent with respect to 100 parts by weight of the (meth) acrylic polymer 13 obtained in Production Example 13. The pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the composition in which) was mixed was used.
[Comparative Example 9]
As a pressure-sensitive adhesive composition, 0.4 parts by weight (solid content) of trimethylolpropane adduct type xylylene diisocyanate takenate D-110N as a crosslinking agent with respect to 100 parts by weight of the (meth) acrylic polymer 14 obtained in Production Example 14. The pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the composition in which) was mixed was used.
[Comparative Example 10]
As a pressure-sensitive adhesive composition, 0.4 parts by weight of trimethylolpropane adduct type xylylene diisocyanate takenate D-110N (solid content) as a crosslinking agent with respect to 100 parts by weight of the (meth) acrylic polymer 15 obtained in Production Example 15. The pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the composition in which) was mixed was used.
[Comparative Example 11]
As a pressure-sensitive adhesive composition, 0.4 parts by weight of trimethylolpropane adduct type xylylene diisocyanate takenate D-110N (solid content) as a crosslinking agent with respect to 100 parts by weight of the (meth) acrylic polymer 16 obtained in Production Example 16. The pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the composition in which) was mixed was used.
[Comparative Example 12]
As a pressure-sensitive adhesive composition, 0.4 parts by weight (solid content) of trimethylolpropane adduct type xylylene diisocyanate takenate D-110N as a crosslinking agent with respect to 100 parts by weight of the (meth) acrylic polymer 17 obtained in Production Example 17. The pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the composition in which) was mixed was used.
[Comparative Example 13]
As a pressure-sensitive adhesive composition, 0.4 parts by weight (solid content) of trimethylolpropane adduct type xylylene diisocyanate takenate D-110N as a crosslinking agent with respect to 100 parts by weight of the (meth) acrylic polymer 18 obtained in Production Example 18. The pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the composition in which) was mixed was used.

表１中の略号は以下の通りである。
ＢＡ・・・ブチルアクリレート
ＭＥＡ・・・メトキシエチルアクリレート
２−ＨＥＡ・・・２−ヒドロキシエチルアクリレート
ＡＡ・・・アクリル酸
ＤＭＡＥＡ・・・ジメチルアミノエチルメタクリレート
ＡＭ・・・アクリルアミド
ｎ−ＶＰ・・・ｎ−ビニルピロリドン
ＡＣＭＯ・・・アクロイルモルホリン
ＰＰＧ・・・ポリプロピレングリコール
Ｄ−１１０Ｎ・・・キシリレンジイソシアネートのトリメチロールプロパン付加体（三井化学社製）
また、Ｍｗの単位は万である。重合に用いられる全モノマーを１００重量部とする。

Abbreviations in Table 1 are as follows.
BA ... butyl acrylate MEA ... methoxyethyl acrylate 2-HEA ... 2-hydroxyethyl acrylate AA ... acrylic acid DMAEA ... dimethylaminoethyl methacrylate AM ... acrylamide n-VP ... n -Vinylpyrrolidone ACMO ... Acroylmorpholine PPG ... Polypropylene glycol D-110N ... Trimethylolpropane adduct of xylylene diisocyanate (Mitsui Chemicals)
The unit of Mw is 10,000. The total monomer used for the polymerization is 100 parts by weight.

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 (21)

Components (a-1), (a-2) and (a-3) shown below
(A-1) 20-99.4% by weight of at least one selected from the group consisting of alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol mono (meth) acrylates,
(A-2) 0.5 to 10% by weight of a monomer having a crosslinkable functional group,
(A-3) Hydrogen bonding monomer 0.1 to 5% by weight
A (meth) acrylic polymer (A) having a weight average molecular weight of substantially 50,000 or more and less than 400,000, which is substantially free of acidic groups obtained by copolymerization of monomers containing 100% by weight of all monomers (including all monomers) ,
With respect to 100 parts by weight of the (meth) acrylic polymer (A), at least one selected from the group consisting of a nonionic surfactant and a polyalkylene glycol (B) 1 to 30 parts by weight, an isocyanate crosslinking agent ( C) A pressure-sensitive adhesive containing 0.05 to 10 parts by weight.   The pressure-sensitive adhesive according to claim 1, wherein the monomer having a crosslinkable functional group is a hydroxyl group-containing monomer.   3. The hydrogen bonding 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 as described.   The pressure-sensitive adhesive according to any one of claims 1 to 3, 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 (meth) acrylic polymer (A) is produced by solution polymerization. Components (a-1), (a-2) and (a-3) shown below
(A-1) 20-99.4% by weight of at least one selected from the group consisting of alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol mono (meth) acrylates,
(A-2) 0.5 to 10% by weight of a monomer having a crosslinkable functional group,
(A-3) Hydrogen bonding monomer 0.1 to 5% by weight
A (meth) acrylic polymer (A) having a weight average molecular weight of substantially 50,000 or more and less than 400,000, which is substantially free of acidic groups obtained by copolymerization of monomers containing 100% by weight of all monomers (including all monomers) ,
With respect to 100 parts by weight of the (meth) acrylic polymer (A), at least one selected from the group consisting of a nonionic surfactant and a polyalkylene glycol (B) 1 to 30 parts by weight, an isocyanate crosslinking agent ( C) A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer having a thickness in the range of 10 to 1000 μm formed from a pressure-sensitive adhesive containing 0.05 to 10 parts by weight.   The pressure-sensitive adhesive sheet according to claim 6, wherein the monomer having a crosslinkable functional group is a hydroxyl group-containing monomer.   The hydrogen bonding monomer is at least one monomer 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 7.   The pressure-sensitive adhesive sheet according to any one of claims 6 to 8, wherein the (meth) acrylic polymer (A) is produced by solution polymerization.   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 a metal oxide. The pressure-sensitive adhesive according to any one of claims 6 to 9, Sheet.   The pressure-sensitive adhesive sheet according to any one of claims 6 to 10, wherein a cover film subjected to a peeling treatment is disposed on at least one surface of the pressure-sensitive adhesive sheet. Components (a-1), (a-2) and (a-3) shown below
(A-1) 20-99.4% by weight of at least one selected from the group consisting of alkoxyalkyl (meth) acrylates and alkoxypolyalkylene glycol mono (meth) acrylates,
(A-2) 0.5 to 10% by weight of a monomer having a crosslinkable functional group,
(A-3) Hydrogen bonding monomer 0.1 to 5% by weight
A (meth) acrylic polymer (A) having a weight average molecular weight of substantially 50,000 or more and less than 400,000, which is substantially free of acidic groups obtained by copolymerization of monomers containing 100% by weight of all monomers (including all monomers) ,
With respect to 100 parts by weight of the (meth) acrylic polymer (A), at least one selected from the group consisting of a nonionic surfactant and a polyalkylene glycol (B) 1 to 30 parts by weight, an isocyanate crosslinking agent ( C) A surface support is adhered to one surface of the pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive containing 0.05 to 10 parts by weight within a range of 10 to 1000 μm. And a transparent conductive film made of a metal, a metal oxide, a metal with an electrode support, or a metal oxide is attached to the other surface of the pressure-sensitive adhesive sheet.   The laminate for a touch panel according to claim 12, wherein the laminate for the touch panel is a member forming a capacitive touch panel.   14. The touch panel laminate according to claim 12, wherein frame printing is performed on an edge portion of a surface of the surface support that faces the pressure-sensitive adhesive layer.   The laminate for a touch panel according to claim 14, wherein the frame printing has a thickness in a range of 10 to 50 µm.   The transparent electrode film is a wiring pattern using ITO and / or ATO as a metal oxide, and the pressure-sensitive adhesive sheet is in direct contact with the wiring pattern. The laminated body for touchscreens as described in an item.   The thickness of the said surface support body exists in the range of 25-2000 micrometers, The laminated body for touchscreens as described in any one of Claims 12-16 characterized by the above-mentioned.   The thickness of the said transparent conductive film exists in the range of 10-100 nm, The laminated body for touchscreens as described in any one of Claims 12-17 characterized by the above-mentioned.   The laminate for a touch panel according to any one of claims 12 to 18, wherein the monomer having a crosslinkable functional group is a hydroxyl group-containing monomer.   The hydrogen-bonding monomer is at least one monomer 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 laminated body for touchscreens as described in any one of 19.   The laminate for a touch panel according to any one of claims 12 to 20, wherein the (meth) acrylic polymer (A) is produced by solution polymerization.

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