JP2021161137A - Adhesive sheet, and method for producing adhesive sheet - Google Patents

Abstract

To provide an adhesive sheet suitable for bonding of various adherends.SOLUTION: An adhesive sheet has a substrate 11, a metal film 12, and an adhesive layer 13 disposed on the metal film. The adhesive layer is formed from an adhesive composition that contains an acrylic copolymer (A) having an alkyl (meth)acrylate-derived constitutional unit (a1) and a carboxylated monomer-derived constitutional unit (a2) and a crosslinker (B). The content of the constitutional unit (a2) is 3.0 mass% or more relative to the total amount of the constitutional units of the acrylic copolymer (A), and the content of the crosslinker (B) is 0.10 pt.mass or more relative to 100 pts.mass of the total amount of the acrylic copolymer (A). The adhesive sheet is used for bonding to soda-lime glass.SELECTED DRAWING: Figure 1

Description

The present invention relates to an adhesive sheet and a method for producing the adhesive sheet.

Adhesive sheets with a metal film having a metal film such as aluminum are used for various purposes such as decorative labels and display labels for various products, and conductive sheets for imparting conductivity.
For example, Patent Document 1 describes a conductive layer formed from a metal thin film formed on one surface of a supporting base material and having conductivity in the surface direction, and a thickness direction covering the surface of the conductive layer. A conductive pressure-sensitive adhesive sheet having a conductive pressure-sensitive adhesive layer and an insulating pressure-sensitive adhesive layer covering the other surface of a supporting base material is disclosed.

Japanese Unexamined Patent Publication No. 2013-216794

Such an adhesive sheet with a metal film is attached to various adherends according to each predetermined use. Adhesive sheets suitable for attaching various adherends are required.

The present invention has a base material, a metal film, and a pressure-sensitive adhesive layer laminated on the surface of the metal film, and the pressure-sensitive adhesive layer is a pressure-sensitive adhesive containing an acrylic copolymer having a predetermined structural unit and a cross-linking agent. Provided are a pressure-sensitive adhesive sheet used for sticking to soda glass, which is a layer formed from an agent composition, and a method for producing the pressure-sensitive adhesive sheet.
Specific aspects of the present invention are as follows [1] to [7].
[1] An adhesive sheet having a base material, a metal film, and an adhesive layer laminated on the surface of the metal film.
The pressure-sensitive adhesive layer contains an acrylic copolymer (A) and a cross-linking agent (B) having a structural unit (a1) derived from an alkyl (meth) acrylate and a structural unit (a2) derived from a carboxy group-containing monomer. A layer formed from the pressure-sensitive adhesive composition,
The content of the constituent unit (a2) is 3.0% by mass or more with respect to the total amount of the constituent units of the acrylic copolymer (A).
The content of the cross-linking agent (B) is 0.10 parts by mass or more with respect to 100 parts by mass of the total amount of the acrylic copolymer (A).
Adhesive sheet used for sticking to soda glass.
[2] The adhesive sheet according to the above [1], wherein the metal film is colored.
[3] The above-mentioned [2], wherein the metal film contains a metal or a metal compound selected from aluminum, chromium, nickel, gold, platinum, silver, tin, copper, iron, palladium, titanium oxide, and titanium nitride. Adhesive sheet.
[4] The pressure-sensitive adhesive sheet according to any one of [1] to [3] above, wherein the pressure-sensitive adhesive layer has a thickness of 1 to 100 μm.
[5] The content of the metal inactivating agent contained in the pressure-sensitive adhesive composition is less than 1 part by mass with respect to 100 parts by mass of the total amount of the acrylic copolymer (A). The adhesive sheet according to any one of [4].
[6] The adhesive sheet according to any one of the above [1] to [5], which is used for attaching soda glass to a non-tin surface.
[7] The method for producing an adhesive sheet according to any one of the above [1] to [6].
A method for producing an adhesive sheet, which comprises the following steps (1) and (2).
-Step (1): A step of applying the pressure-sensitive adhesive composition to the surface of a metal film provided on a base material to form a coating film.
-Step (2): A step of drying the coating film.

The pressure-sensitive adhesive sheet of one preferred aspect of the present invention is suitable for sticking to soda glass, for example, so-called "evaporation skipping" in which at least a part of a metal film is oxidized and deteriorated by moisture in the atmosphere. It can be effectively suppressed.

It is a schematic cross-sectional view of the pressure-sensitive adhesive sheet which showed an example of the structure of the pressure-sensitive adhesive sheet of one aspect of this invention.

In addition, in this specification, for example, "(meth) acrylate" is used as a term indicating both "acrylate" and "methacrylate", and the same applies to other similar terms.
Further, the "active ingredient" of the pressure-sensitive adhesive composition means a component contained in the pressure-sensitive adhesive composition excluding a diluting solvent such as an organic solvent.

[Structure of adhesive sheet]
The pressure-sensitive adhesive sheet of the present invention is not particularly limited as long as it has a structure having a base material, a metal film, and a pressure-sensitive adhesive layer laminated on the surface of the metal film, and may have layers other than these.
For example, FIG. 1 is a schematic cross-sectional view of the pressure-sensitive adhesive sheet showing an example of the structure of the pressure-sensitive adhesive sheet according to one aspect of the present invention.

As a specific configuration of the pressure-sensitive adhesive sheet according to one aspect of the present invention, as in the pressure-sensitive adhesive sheet 1a of FIG. 1A, a metal film 12 is laminated on one surface of the base material 11, and the metal film 12 is further laminated. There is a structure in which the pressure-sensitive adhesive layer 13 is laminated on the upper surface, but the present invention is not limited to this.
For example, as in the pressure-sensitive adhesive sheet 1b of FIG. 1B, the metal films 12a and 12b are laminated on both surfaces of the base material 11, and the pressure-sensitive adhesive layer 13a is further laminated on the surface of the metal film 12a. The adhesive layer 13b may be laminated on the surface of the metal film 12b.

Further, in the pressure-sensitive adhesive sheet of one aspect of the present invention, as in the pressure-sensitive adhesive sheet 1c of FIG. 1 (c), a release sheet 14 is further formed on the surface of the pressure-sensitive adhesive layer 13 of the pressure-sensitive adhesive sheet 1a of FIG. It may be a laminated structure.
Similarly, as in the pressure-sensitive adhesive sheet 1d of FIG. 1 (d), a release sheet 14a is further laminated on the surface of the pressure-sensitive adhesive layer 13a of the pressure-sensitive adhesive sheet 1b of FIG. 1 (b), and the surface of the pressure-sensitive adhesive layer 13b is further laminated. A release sheet 14b may be further laminated on the top.
The materials of the two release sheets 14a and 14b of the adhesive sheet 1d may be the same or different from each other, but the release force of the release sheet 14a and the release sheet 14b is adjusted to be different. It is preferable to have.

In addition, in the configuration of the pressure-sensitive adhesive sheet 1a of FIG. 1A, a peeling treatment is performed on the surface of the base material 11 opposite to the surface on which the metal film 12 is laminated, and the surface is wound in a roll shape. It may be an adhesive sheet having.
In the pressure-sensitive adhesive sheet of one aspect of the present invention, the base material and the metal film may be directly laminated as in the pressure-sensitive adhesive sheet 1a shown in FIG. 1, and may be directly laminated between the base material and the metal film. It may have a structure having another layer.

In general, when an adhesive sheet with a metal film is left to stand for a long period of time while being attached to an adherend, at least a part of the metal film is oxidized by moisture in the atmosphere and deteriorates, so-called "evaporation skipping". May occur. Note that "thin-film deposition skipping" is a phenomenon that can occur not only in a metal vapor deposition film formed by vapor deposition but also in a metal film formed by a method other than vapor deposition. As used herein, the term "thin-film deposition skipping" means a phenomenon in which at least a part of a metal film formed by a method by vapor deposition or a method other than vapor deposition is oxidized and deteriorated.
For example, if vapor deposition skipping occurs in at least a part of a colored metal film having metallic luster, the portion where the vapor deposition skipping occurs is discolored, resulting in an adhesive sheet having an appearance as if there were holes. In this case, when the adhesive sheet is used as a decorative label or a display label, there is an adverse effect that the appearance of these labels is impaired.
Further, even in a transparent metal film such as indium tin oxide (ITO), if vapor deposition skipping occurs, there is a concern that the properties required for the metal film such as conductivity may be deteriorated.

In particular, it has been found by the present inventor that this problem of thin film deposition is likely to occur when the glass is attached to the soda glass, and further when the glass is attached to the non-tin surface of the soda glass.
On the other hand, the pressure-sensitive adhesive sheet according to one aspect of the present invention is a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing an acrylic copolymer (A) having a predetermined structural unit and a cross-linking agent (B), as described later. Therefore, it has a characteristic of being excellent in suppressing vapor deposition skipping, and even when it is attached to soda glass, it has a high effect of suppressing vapor deposition skipping.
Therefore, the adhesive sheet of one aspect of the present invention can be suitably used for sticking to soda glass, and is particularly suitable for sticking to a non-tin surface of soda glass in an environment where vapor deposition skipping is more likely to occur. There is.
Hereinafter, the configuration of each layer of the pressure-sensitive adhesive sheet according to one aspect of the present invention will be described.

<Base material>
The base material contained in the pressure-sensitive adhesive sheet according to one aspect of the present invention is appropriately selected depending on the intended use, and examples thereof include a paper base material, a porous base material such as a non-woven fabric, and a resin film.

Examples of the paper material constituting the paper base material include thin-leaf paper, medium-quality paper, high-quality paper, impregnated paper, coated paper, art paper, sulfated paper, and glassin paper.

Examples of the resin constituting the resin film include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resins such as polyethylene and polypropylene; polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, and ethylene-vinyl acetate. Vinyl-based resins such as copolymers and ethylene-vinyl alcohol copolymers; polystyrene; acrylonitrile-butadiene-styrene copolymers; cellulose triacetate; polycarbonate; urethane resins such as polyurethane and acrylic-modified polyurethane; polymethylpentene; polysulfone; Polyether ether ketone; polyether sulfone; polyphenylene sulfide; polyimide resin such as polyetherimide and polyimide; polyamide resin; acrylic resin; fluorine resin and the like can be mentioned.

These resin films may be composed of only one type of resin or may be composed of two or more types of resins.
Further, the resin film used in one embodiment of the present invention contains various additives such as an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a slip agent, an anti-blocking agent, and a colorant in addition to the above-mentioned resin. You may be doing it.

The resin film may be unstretched or may be stretched in a uniaxial direction or a biaxial direction such as vertical or horizontal.
Further, the resin film may be a resin film having a cavity-containing layer containing a cavity inside. A resin film may be formed in which a resin layer containing no cavities is further laminated on at least one surface side of the cavity-containing layer.

The base material used in one embodiment of the present invention may be a single-layer base material made of the above-mentioned paper base material or resin film, and may be a multi-layer base material obtained by laminating two or more kinds selected from the paper base material and the resin film. It may be a base material.
Examples of the multilayer base material include a laminated resin film obtained by laminating two or more kinds of resin films, a laminated base material obtained by laminating a paper base material with a thermoplastic resin such as polyethylene, and the like.

When the base material used in one embodiment of the present invention is a resin film or a laminated base material, the surface of these base materials is subjected to surface treatment such as an oxidation method or an unevenness method, or a primer treatment. May be good.
The oxidation method is not particularly limited, and examples thereof include a corona discharge treatment method, a plasma treatment method, chromium acid oxidation (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like.
The unevenness method is not particularly limited, and examples thereof include a sandblast method and a solvent treatment method.

The thickness of the base material used in one embodiment of the present invention is preferably 1 to 1000 μm, more preferably 5 to 500 μm, further preferably 10 to 300 μm, still more preferably 15 to 150 μm, and particularly preferably 20 to 120 μm. ..

<Metal film>
The metal film included in the pressure-sensitive adhesive sheet according to one aspect of the present invention is a film containing a metal or a metal compound.
The metal or metal compound constituting the metal film is appropriately selected depending on the intended use. For example, aluminum, chromium, nickel, gold, platinum, silver, tin, copper, iron, palladium, titanium oxide, titanium nitride, etc. Examples thereof include indium tin oxide (ITO).
The metal film contained in the pressure-sensitive adhesive sheet of one aspect of the present invention may be a metal film containing only one type selected from the above metals, or may be a metal film containing two or more types selected from the above metals.

Further, the metal film may be colored or transparent (colorless).
For example, when the pressure-sensitive adhesive sheet of one aspect of the present invention is used as a decorative label or a display label, the metal film becomes colored. The pressure-sensitive adhesive sheet according to one aspect of the present invention has a characteristic of being excellent in suppressing vapor deposition skipping, and is unlikely to cause an adverse effect that the appearance of the label is impaired due to the occurrence of vapor deposition skipping.
When the metal film is colored, the metal film contains a metal or a metal compound selected from aluminum, chromium, nickel, gold, platinum, silver, tin, copper, iron, palladium, titanium oxide, and titanium nitride. Is preferable.

As a method for forming the metal film, the above-mentioned metal or metal compound is vapor-deposited by a PVD (physical vapor deposition) method such as vacuum deposition, sputtering, ion plating, or a film (metal) composed of the above-mentioned metal or metal compound. A method of attaching the foil) using a general adhesive can be mentioned.
When the metal film is a metal vapor-deposited film formed by thin-film deposition, it is general that vapor deposition skipping is more likely to occur. However, the pressure-sensitive adhesive sheet according to one aspect of the present invention has a characteristic of being excellent in the effect of suppressing vapor deposition skipping. Therefore, even when the pressure-sensitive adhesive sheet of one aspect of the present invention has a metal-deposited film as the metal film, it is possible to effectively suppress the vapor deposition skipping that may occur on the metal-deposited film.

The film thickness of the metal film of the pressure-sensitive adhesive sheet according to one aspect of the present invention is preferably 1 to 5000 nm, more preferably 5 to 1000 nm, still more preferably 10 to 500 nm, and even more preferably 20 to 300 nm.

<Adhesive layer, adhesive composition>
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of the present invention is an acrylic copolymer (A) having a structural unit (a1) derived from an alkyl (meth) acrylate and a structural unit (a2) derived from a carboxy group-containing monomer, and a crosslink. It is a layer formed from the pressure-sensitive adhesive composition containing the agent (B).
Then, the pressure-sensitive adhesive composition satisfies the following requirements (I) and (II).
-Requirement (I): The content of the constituent unit (a2) is 3.0% by mass or more with respect to the total amount of the constituent units of the acrylic copolymer (A).
-Requirement (II): The content of the cross-linking agent (B) is 0.10 parts by mass or more with respect to 100 parts by mass of the total amount of the acrylic copolymer (A).

Since the pressure-sensitive adhesive sheet of one aspect of the present invention has a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition satisfying the above requirements (I) and (II), the effect of suppressing vapor deposition skipping can be improved. In particular, when it is attached to soda glass, and further when it is attached to the non-tin surface of soda glass, the effect of suppressing possible vapor deposition skipping can be effectively exhibited.

In various studies, the present inventor has found that when the pressure-sensitive adhesive sheet with a metal film is attached to soda glass, particularly when it is attached to the non-tin surface of soda glass, thin-film deposition skipping is likely to occur. .. The reason for this is thought to be as follows.
Soda glass, together with quartz sand (SiO _2), sodium carbonate _(Na 2 _CO 3), calcium carbonate (CaCO ₃₎ and magnesium carbonate (CaCO ₃₎ in which metal salt by mixing the prepared melts such as be. Therefore, soda glass contains metal oxides derived from metal salts such as sodium oxide (Na ₂ O), calcium oxide (CaO) and magnesium oxide (MgO). The metal ions derived from these metal oxides migrate to the pressure-sensitive adhesive layer and the metal film of the pressure-sensitive adhesive sheet with a metal film attached to the surface of the soda glass to promote the oxidation of the metal film, resulting in vapor deposition. It is presumed that jumping will occur.
Then, it was found by the present inventor that when the pressure-sensitive adhesive sheet with a metal film is attached to the non-tin surface of the soda glass, the vapor deposition skipping is more likely to occur than when the adhesive sheet with the metal film is attached to the tin surface. Therefore, it is considered that the metal ions derived from the above-mentioned metal oxides are more likely to be transferred to the metal film of the pressure-sensitive adhesive sheet on the non-tin surface.

Therefore, the present inventor adjusts the content of the structural unit (a2) derived from the carboxyl group-containing monomer constituting the acrylic copolymer (A) in the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer. , An attempt was made to suppress the transfer of metal ions derived from the metal oxide contained in soda glass to the metal film. That is, on the adhesive surface of the pressure-sensitive adhesive layer with the soda glass, the metal ion derived from the metal oxide contained in the soda glass is contained in the carboxy group (-) of the constituent unit (a2) of the acrylic copolymer (A). It was speculated that COOH) could capture and suppress the transfer to the metal film. Then, based on that guess, a diligent study was conducted, and when the content of the carboxy group contained in the constituent unit (a2) of the acrylic copolymer (A) was adjusted so as to satisfy the above requirement (I), the vapor deposition skipped. It was found that it can be an adhesive sheet with an improved inhibitory effect.

Further, by forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of one aspect of the present invention from a pressure-sensitive adhesive composition that satisfies the above-mentioned requirement (I) and the above-mentioned requirement (II), the effect of suppressing vapor deposition skipping can be obtained. It is possible to obtain a good pressure-sensitive adhesive sheet by increasing the cohesive force in the pressure-sensitive adhesive layer.
In addition, the pressure-sensitive adhesive sheet according to one aspect of the present invention is a high-temperature and high-humidity environment in which vapor deposition skipping is likely to occur by forming the pressure-sensitive adhesive layer from a pressure-sensitive adhesive composition satisfying the requirements (I) and (II). It was found that the effect of suppressing vapor deposition skipping was excellent even when the film was left to stand for a long period of time while being attached to soda glass below. This is because, by satisfying the requirement (II), the cohesive force of the formed pressure-sensitive adhesive layer is increased, and it becomes difficult for water containing metal ions to move in the pressure-sensitive adhesive layer, and the transfer of metal ions to the metal film is further increased. It is presumed to be effective in suppressing it.

The content of the structural unit (a2) specified in the above requirement (I) is 3.0% by mass or more with respect to the total amount of the structural units of the acrylic copolymer (A), but is preferably 3.2. It is by mass% or more, more preferably 3.4% by mass or more, still more preferably 3.5% by mass or more, still more preferably 4.0% by mass or more, and particularly preferably 4.5% by mass or more.
Further, the content of the constituent unit (a2) is preferably 50% by mass or less, more preferably 50% by mass or less, based on the total amount of the constituent units of the acrylic copolymer (A) from the viewpoint of forming an adhesive sheet having excellent adhesive strength. Is 40% by mass or less, more preferably 35% by mass or less, still more preferably 30% by mass or less, still more preferably 25% by mass or less, and particularly preferably 20% by mass or less.
That is, in one aspect of the present invention, the content of the structural unit (a2) is preferably 3.0 to 50% by mass, more preferably 3 with respect to the total amount of the structural units of the acrylic copolymer (A). .2 to 40% by mass, more preferably 3.4 to 35% by mass, still more preferably 3.5 to 30% by mass, even more preferably 4.0 to 25% by mass, particularly preferably 4.5 to 20% by mass. %.

The content of the cross-linking agent (B) specified in the above requirement (II) is 0.10 parts by mass or more, preferably 0, with respect to 100 parts by mass of the total amount of the acrylic copolymer (A). .50 parts by mass or more, more preferably 0.70 parts by mass or more, still more preferably 1.00 parts by mass or more, still more preferably 1.20 parts by mass or more, particularly preferably 1.60 parts by mass or more, and , Preferably 15.0 parts by mass or less, more preferably 12.0 parts by mass or less, more preferably 10.0 parts by mass or less, still more preferably 8.0 parts by mass or less, still more preferably 6.0 parts by mass or less. , Especially preferably 4.5 parts by mass or less.
That is, in one aspect of the present invention, the content of the cross-linking agent (B) is preferably 0.10 to 15.0 parts by mass, more preferably 0.1 to 15.0 parts by mass, based on 100 parts by mass of the total amount of the acrylic copolymer (A). Is 0.50 to 12.0 parts by mass, more preferably 0.70 to 10.0 parts by mass, still more preferably 1.00 to 8.0 parts by mass, still more preferably 1.20 to 6.0 parts by mass. , Particularly preferably 1.60 to 4.5% by mass.

The thickness of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to one aspect of the present invention is appropriately adjusted depending on the application and the like, but is preferably 1 to 100 μm, more preferably 2 to 80 μm, still more preferably 3 to 60 μm, and further. It is preferably 5 to 50 μm.

The pressure-sensitive adhesive composition, which is a material for forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of one aspect of the present invention, contains an acrylic copolymer (A) and a cross-linking agent (B), but further contains a pressure-sensitive adhesive (C). It may be contained, and an additive for an adhesive other than the components (A) to (C) may be contained.

In the pressure-sensitive adhesive composition used in one aspect of the present invention, the total content of the components (A) and (B) is preferably relative to the total amount (100% by mass) of the active ingredients of the pressure-sensitive adhesive composition. It is 30 to 100% by mass, more preferably 50 to 100% by mass, still more preferably 60 to 100% by mass, still more preferably 70 to 100% by mass, and particularly preferably 80 to 100% by mass.
Hereinafter, each component contained in the pressure-sensitive adhesive composition used in one aspect of the present invention will be described.

<Component (A): Acrylic copolymer>
The acrylic copolymer (A) used in one embodiment of the present invention is a structural unit (a1) derived from an alkyl (meth) acrylate (hereinafter, also referred to as “monomer (a1 ′)”) and a carboxy group-containing monomer (hereinafter, also referred to as “monomer (a1 ′)”). , Also referred to as "monomer (a2')").
The acrylic copolymer (A) may be used alone or in combination of two or more.
Further, the acrylic copolymer (A) used in one aspect of the present invention may be an emulsion type polymer or a non-emulsion type polymer, but is preferably a non-emulsion type polymer.
Further, the form of copolymerization of the acrylic copolymer (A) is not particularly limited, and may be any of a random copolymer, a block copolymer, and a graft copolymer.

The mass average molecular weight (Mw) of the acrylic copolymer (A) used in one embodiment of the present invention is preferably 50,000 to 2 million, more preferably 100,000 to 1.8 million, still more preferably 200,000 to 1.5 million. Even more preferably, it is 250,000 to 1.2 million, and particularly preferably 300,000 to 1 million.
In the present specification, the mass average molecular weight (Mw) is a polystyrene-equivalent value measured by a gel permeation chromatography (GPC) method, and is specifically measured based on the method described in Examples. Value.

In the pressure-sensitive adhesive composition used in one aspect of the present invention, the content of the acrylic copolymer (A) is preferably 30% by mass with respect to the total amount (100% by mass) of the active ingredient of the pressure-sensitive adhesive composition. The above is more preferably 40% by mass or more, further preferably 50% by mass or more, still more preferably 60% by mass or more, particularly preferably 70% by mass or more, and preferably 99.95% by mass or less, more preferably. Is 99.9% by mass or less, more preferably 99.5% by mass or less, still more preferably 99.0% by mass or less, and particularly preferably 98.5% by mass or less.
That is, the content of the acrylic copolymer (A) is preferably 30 to 99.95% by mass, more preferably 40 to 99, based on the total amount (100% by mass) of the active ingredient of the pressure-sensitive adhesive composition. It is 9.9% by mass, more preferably 50 to 99.5% by mass, still more preferably 60 to 99.0% by mass, and particularly preferably 70 to 98.5% by mass.

The acrylic copolymer (A) used in one embodiment of the present invention has a common weight having a structural unit (a3) derived from a functional group-containing monomer other than the carboxy group (hereinafter, also referred to as “monomer (a3')”). It may be a coalescence, and a structural unit (a4) derived from a monomer other than the monomers (a1'), (a2') and (a3') (hereinafter, also referred to as "monomer (a4')") is used. It may be a copolymer having.

In the acrylic copolymer (A) used in one aspect of the present invention, the total content of the structural units (a1) and (a2) is the total mass (100) of the structural units of the acrylic copolymer (A). With respect to (% by mass), preferably 35 to 100% by mass, more preferably 45 to 100% by mass, more preferably 55 to 100% by mass, still more preferably 65 to 100% by mass, still more preferably 75 to 100% by mass. , More preferably 85 to 100% by mass, and particularly preferably 90 to 100% by mass.
Hereinafter, the monomers and constituent units constituting the acrylic copolymer (A) will be described.

[Monomer (a1'), constituent unit (a1)]
The number of carbon atoms of the alkyl group contained in the monomer (a1') is preferably 1 to 30, more preferably 1 to 20, still more preferably 1 to 16, still more preferably 1 to 12, and particularly preferably 4 to 8. be.
The alkyl group contained in the monomer (a1') may be a straight chain alkyl group or a branched chain alkyl group.

Examples of the monomer (a1') include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate (n-propyl (meth) acrylate, i-propyl (meth) acrylate), and butyl (meth) acrylate. (N-butyl (meth) acrylate, i-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate), pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) Examples thereof include acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, tridecyl (meth) acrylate, and stearyl (meth) acrylate.
These monomers (a1') may be used alone or in combination of two or more.

The acrylic copolymer (A) used in one embodiment of the present invention is an alkyl (meth) acrylate having an alkyl group having 4 to 8 carbon atoms as a structural unit (a1) (hereinafter, “monomer (a11 ′)). It is preferable to have a structural unit (a11) derived from "also referred to as".

The monomer (a11') may contain at least one selected from butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Preferably, it contains butyl (meth) acrylate or 2-ethylhexyl (meth) acrylate, and even more preferably butyl (meth) acrylate.

The content ratio of the structural unit (a11) is preferably 60 to 100% by mass, more preferably 70 to 70 to the total amount (100% by mass) of the structural unit (a1) contained in the acrylic copolymer (A). It is 100% by mass, more preferably 80 to 100% by mass, still more preferably 90 to 100% by mass, and particularly preferably 95 to 100% by mass.

In the acrylic copolymer (A) used in one aspect of the present invention, the content of the structural unit (a1) is based on the total amount (100% by mass) of the structural units of the acrylic copolymer (A). It is preferably 30% by mass or more, more preferably 40% by mass or more, further preferably 50% by mass or more, still more preferably 60% by mass or more, particularly preferably 70% by mass or more, and preferably 97.0% by mass. % Or less, more preferably 96.5% by mass or less, still more preferably 96.0% by mass or less, still more preferably 95.0% by mass or less, and particularly preferably 94.0% by mass or less.
That is, the content of the structural unit (a1) is preferably 30 to 97.0% by mass, more preferably 40 to 40% by mass, based on the total amount (100% by mass) of the structural unit of the acrylic copolymer (A). It is 96.5% by mass, more preferably 50 to 96.0% by mass, still more preferably 60 to 95.0% by mass, and particularly preferably 70 to 94.0% by mass.

[Monomer (a2'), constituent unit (a2)]
Examples of the monomer (a2') include ethylenically unsaturated monocarboxylic acids such as (meth) acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, maleic acid and citraconic acid; 2- Examples thereof include carboxylethyl (meth) acrylate.
These monomers (a2') may be used alone or in combination of two or more.

The monomer (a2') used in one aspect of the present invention preferably contains an ethylenically unsaturated monocarboxylic acid, and more preferably contains (meth) acrylic acid.
The content of the structural unit (a2) is adjusted so as to satisfy the above requirement (I), and the suitable range is also as described above.

[Monomer (a3'), constituent unit (a3)]
The acrylic copolymer (A) used in one embodiment of the present invention may be a copolymer having a structural unit (a3) derived from a functional group-containing monomer (monomer (a3')) other than the carboxy group. ..
Examples of the monomer (a3') include a hydroxy group-containing monomer and an epoxy group-containing monomer.
These monomers (a3') may be used alone or in combination of two or more.

Examples of the hydroxy-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxybutyl (meth) acrylate. ) Hydroxyalkyl (meth) acrylates such as acrylate and 4-hydroxybutyl (meth) acrylate; unsaturated alcohols such as vinyl alcohol and allyl alcohol can be mentioned.
The alkyl group of the hydroxyalkyl (meth) acrylates has preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms. The alkyl group may be a straight chain alkyl group or a branched chain alkyl group.

Examples of the epoxy-containing monomer include glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, (3,4-epoxycyclohexyl) methyl (meth) acrylate, and 3-epoxycyclo-2-hydroxypropyl (meth) acrylate. Epoxy group-containing (meth) acrylic acid ester such as glycidyl crotonate, allyl glycidyl ether and the like.

In the acrylic copolymer (A) used in one embodiment of the present invention, the content of the structural unit (a3) is based on the total amount (100% by mass) of the structural units of the acrylic copolymer (A). It is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, still more preferably 20% by mass or less, and particularly preferably 10% by mass or less.
The content of the structural unit (a3) is not particularly limited to the lower limit value, and is 0% by mass or more, 0.01% by mass, based on the total amount (100% by mass) of the structural unit of the acrylic copolymer (A). It may be mass% or more, 0.05 mass% or more, 0.1 mass% or more, 0.2 mass% or more, 0.3 mass% or more, 0.4 mass% or more, 0.5 mass% or more.
Regarding the content of the structural unit (a3), the above lower limit and upper limit can be arbitrarily selected and combined.

[Monomer (a4'), constituent unit (a4)]
The acrylic copolymer (A) used in one embodiment of the present invention is a structural unit derived from a monomer (monomer (a4')) other than the monomers (a1'), (a2') and (a3'). It may be a copolymer having a4).
The monomer (a4') is not particularly limited, and examples thereof include olefins such as ethylene, propylene and isobutylene, halogenated olefins such as vinyl chloride and vinylidene chloride, and diene monomers such as butadiene, isoprene and chloroprene. Examples thereof include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, (meth) acrylamide, (meth) acrylonitrile, (meth) acryloylmorpholine, and N-vinylpyrrolidone.
These monomers (a4') may be used alone or in combination of two or more.

In the acrylic copolymer (A) used in one aspect of the present invention, the content of the structural unit (a4) is based on the total amount (100% by mass) of the structural units of the acrylic copolymer (A). It is preferably 0 to 40% by mass, more preferably 0 to 30% by mass, still more preferably 0 to 20% by mass, still more preferably 0 to 10% by mass, and particularly preferably 0 to 5% by mass.

<Other adhesive resins>
The pressure-sensitive adhesive composition used in one aspect of the present invention may further contain a pressure-sensitive adhesive resin other than the component (A) as long as the effects of the present invention are not impaired.
The other adhesive resin may be a resin having adhesiveness by itself, but for example, it can be polymerized with urethane-based resin, rubber-based resin, olefin-based resin, silicone-based resin, and these resins. Examples thereof include a curable resin into which a group has been introduced.
These other adhesive resins may be used alone or in combination of two or more.
Further, the other adhesive resin may be an emulsion type resin or a non-emulsion type resin, but a non-emulsion type resin is preferable.

The mass average molecular weight (Mw) of the other adhesive resin used in one aspect of the present invention is preferably 10,000 to 2 million, more preferably 20,000 to 1.8 million, and even more preferably 30,000 to 1.5 million.

In the pressure-sensitive adhesive composition used in one aspect of the present invention, the content of the pressure-sensitive resin other than the component (A) is based on 100 parts by mass of the total amount of the component (A) contained in the pressure-sensitive adhesive composition. It is preferably 0 to 100 parts by mass, more preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, still more preferably 0 to 10 parts by mass, still more preferably 0 to 5 parts by mass, still more preferably 0 to 0 parts by mass. It is 1 part by mass, particularly preferably 0 to 0.1 part by mass.

<Component (B): Crosslinking agent>
Examples of the cross-linking agent (B) used in one embodiment of the present invention include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, imine-based cross-linking agents, and metal chelate-based cross-linking agents.
These cross-linking agents (B) may be used alone or in combination of two or more.
Further, the content of the cross-linking agent (B) is adjusted so as to satisfy the above requirement (II), and the suitable range is also as described above.

Examples of the isocyanate-based cross-linking agent include tolylene diisocyanate compounds such as 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate; Range isocyanate compounds; diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2 , 4'-diisocyanate, lysine isocyanate and the like.
In addition, a trimer of these organic polyvalent isocyanate compounds, a terminal isocyanate urethane prepolymer obtained by reacting these organic polyvalent isocyanate compounds with a polyol compound, and the like can also be used.

Examples of the epoxy-based cross-linking agent include bisphenol A type epoxy compound, bisphenol F type epoxy compound, 1,3-bis (N, N-diglycidylaminomethyl) toluene, N, N, N', N'-tetraglycidyl. -4,4-diaminodiphenylmethane and the like can be mentioned.

Examples of the imine-based cross-linking agent include N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxyamide), trimethylolpropane-tri-β-aziridinyl propionate, and trimethylolmethane-tri. Examples thereof include -β-aziridinyl propionate, N, N'-toluene-2,4-bis (1-aziridinecarboxyamide) triethylene melamine and the like.

Examples of the metal chelate-based cross-linking agent include coordination compounds of polyvalent metals such as aluminum chelate-based compounds such as trisethylacetoacetate aluminum, ethylacetacetate aluminum diisopropyrate, and trisacetylacetonate aluminum.

The cross-linking agent (B) used in one embodiment of the present invention preferably contains at least one selected from an isocyanate-based cross-linking agent and a metal chelate-based cross-linking agent, and more preferably contains at least an isocyanate-based cross-linking agent. It is more preferable to contain at least an isocyanate-based compound.

<Adhesive imparting agent (C)>
The pressure-sensitive adhesive composition used in one aspect of the present invention may further contain a pressure-sensitive adhesive (C).
In the present specification, the tackifier is a component that supplementarily improves the tackiness of the acrylic copolymer (A), which is a tacky resin, and usually has a mass average molecular weight (Mw) of 10,000. It is less than an oligomer and is distinguished from the above-mentioned adhesive resin containing the acrylic copolymer (A).
The mass average molecular weight (Mw) of the tackifier (C) used in one aspect of the present invention is preferably 400 to 4000, more preferably 800 to 1500.

Examples of the tackifier (C) used in one embodiment of the present invention include rosin-based resin, terpene-based resin, styrene-based resin, hydrocarbon-based resin, and hydrogenated resin obtained by hydrogenating these resins. ..
These tackifiers (C) may be used alone or in combination of two or more.

Examples of the rosin-based resin include a rosin resin, a rosin ester resin, a rosin phenol resin, and the like, and a hydrogenated rosin-based resin obtained by hydrogenating these resins may be used.
The terpene-based resin may be a compound having a structural unit derived from isopene, and examples thereof include terpene resins, aromatic-modified terpene resins, and terpene phenol-based resins, and hydrogenation of these resins. It may be a terpene resin.
Examples of the styrene-based resin include a resin obtained by copolymerizing a styrene-based monomer such as α-methylstyrene or β-methylstyrene with an aliphatic monomer, and hydrogenated styrene obtained by hydrogenating the resin. It may be a styrene resin.
Examples of the hydrocarbon resin include a C5 hydrocarbon resin obtained by copolymerizing C5 fractions such as penten, isoprene, piperin, and 1.3-pentadiene produced by thermal decomposition of petroleum naphtha; heat of petroleum naphtha. Examples thereof include C9-based hydrocarbon resins obtained by copolymerizing C9 fractions such as inden and vinyl toluene produced by decomposition; and hydrocarbon resins obtained by hydrogenating these.

The softening point of the tackifier (C) used in one embodiment of the present invention is preferably 70 to 170 ° C, more preferably 80 to 160 ° C, still more preferably 85 to 150 ° C, still more preferably 90 to 140 ° C. be.
In this specification, the softening point of the tackifier (C) means a value measured in accordance with JIS K2531.
When two or more kinds of tackifiers are used in combination, it is preferable that the weighted average value calculated from the softening point and the blending amount ratio of each tackifier is in the above range.

When the pressure-sensitive adhesive composition used in one aspect of the present invention contains a pressure-sensitive adhesive (C), the content of the pressure-sensitive adhesive (C) is the acrylic copolymer (A) contained in the pressure-sensitive adhesive composition. It is preferably 5 to 300 parts by mass, more preferably 10 to 200 parts by mass, still more preferably 20 to 180 parts by mass, and even more preferably 30 to 150 parts by mass with respect to 100 parts by mass of the total amount.

<Additives for adhesives>
The pressure-sensitive adhesive composition used in one aspect of the present invention may further contain an additive for a pressure-sensitive adhesive other than the cross-linking agent (B) and the pressure-sensitive adhesive (C) as long as the effects of the present invention are not impaired.
Examples of such additives for adhesives include plasticizers (liquid resins, liquid paraffins, etc.), compatibilizers, wetting agents, thickeners, antifoaming agents, ultraviolet absorbers, antioxidants, fillers, and the like. Examples thereof include rust preventives, antibacterial agents, insect repellents, fragrances, pigments, dyes, curing agents, curing aids, catalysts and the like.
Each of these additives may be used alone or in combination of two or more.

When the pressure-sensitive adhesive composition used in one aspect of the present invention contains these pressure-sensitive adhesive additives, the content of each of the pressure-sensitive adhesive additives is appropriately set according to the type of the additive. With respect to 100 parts by mass of the total amount of the acrylic copolymer (A), preferably 0.01 to 40 parts by mass, more preferably 0.05 to 30 parts by mass, still more preferably 0.1 to 20 parts by mass, and more. More preferably, it is 0.2 to 10 parts by mass.

The pressure-sensitive adhesive composition according to one aspect of the present invention may contain a metal inactivating agent, but since it is a persistent substance itself, it contains the metal inactivating agent from the viewpoint of the environment. The smaller the amount, the more preferable.
The specific content of the metal inactivating agent is preferably less than 1 part by mass, more preferably less than 0.1 part by mass, still more preferably, with respect to 100 parts by mass of the total amount of the acrylic copolymer (A). Is less than 0.01 parts by mass, more preferably less than 0.001 parts by mass, particularly preferably less than 0.0001 parts by mass or 0 parts by mass (that is, it does not contain a metal inactivating agent).

Examples of the metal inactivating agent include benzotriazole, 4-methylbenzotriazole, 5-methylbenzotriazole, 5-chlorobenzotriazole, triltriazole, potassium salt of triltriazole, and 3- (N-salicyloyl) amino. Examples thereof include -1,2,4-triazole and 2- (2'-hydroxy-5-methylphenyl) benzotriazole.

<Organic solvent>
The pressure-sensitive adhesive composition used in one aspect of the present invention may be further diluted with an organic solvent to form a solution from the viewpoint of facilitating the formation of a coating film and improving workability.
Examples of the organic solvent include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, isopropanol and the like.
These organic solvents may be used alone or in combination of two or more.
As these organic solvents, the organic solvent used in the synthesis of the acrylic copolymer (A) may be used as it is, or other than the organic solvent used in the synthesis of the acrylic copolymer (A). One or more organic solvents may be added.

The concentration of the active ingredient of the pressure-sensitive adhesive composition used in one aspect of the present invention is preferably 5 to 80% by mass, more preferably 10 to 70% by mass, based on the total amount (100% by mass) of the pressure-sensitive adhesive composition. , More preferably 15 to 60% by mass.

<Release sheet>
The pressure-sensitive adhesive sheet of one aspect of the present invention may further have a release sheet on the surface of the pressure-sensitive adhesive layer.
Examples of the release sheet used in one aspect of the present invention include a sheet having a release agent layer formed from a release agent on one side or both sides of the release sheet base material.

Examples of the base material for the release sheet include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyurethane, and ethylene-. Resin films such as vinyl acetate copolymer, ionomer resin, ethylene (meth) acrylic acid copolymer, polystyrene, polycarbonate, fluororesin, low-density polyethylene, linear low-density polyethylene, triacetyl cellulose, high-quality paper, coated paper , Paper base material such as glassin paper, laminated paper in which a thermoplastic resin such as polyethylene is laminated on these paper base materials and the like.

Examples of the release agent forming the release agent layer include silicone-based resins, olefin-based resins, long-chain alkyl-based resins, alkyd-based resins, fluorine-based resins, isoprene-based resins, butadiene-based resins, and other rubber-based elastomers. Be done.

The thickness of the release sheet is not particularly limited, but is preferably 5 to 300 μm, more preferably 7 to 200 μm, and further preferably 10 to 150 μm. When a resin film is used as the base material for the release sheet, the thickness is even more preferably 10 to 100 μm.

[Manufacturing method of adhesive sheet]
The method for producing the pressure-sensitive adhesive sheet according to one aspect of the present invention is not particularly limited, but a method having the following steps (1) and (2) is preferable from the viewpoint of producing a pressure-sensitive adhesive sheet excellent in the effect of suppressing vapor deposition skipping. ..
-Step (1): A step of applying the pressure-sensitive adhesive composition to the surface of a metal film provided on a base material to form a coating film.
-Step (2): A step of drying the coating film.

As in step (1), the pressure-sensitive adhesive composition is directly applied to the surface of the metal film to form a coating film, so that the surface of the pressure-sensitive adhesive layer on the metal film side is formed in the pressure-sensitive adhesive layer. It is possible to obtain a pressure-sensitive adhesive sheet in which the carboxy group (-COOH) of the acrylic copolymer (A) is more unevenly distributed. As a result, when the obtained pressure-sensitive adhesive sheet is attached to the soda glass, the metal ions that may be generated from the metal oxide contained in the soda glass are transferred to the carboxy group in the pressure-sensitive adhesive layer before being transferred to the metal film. -COOH) can be reacted to suppress the transfer of metal ions to the metal film.

In step (1), it is necessary to form a metal film on the base material in advance.
As a method for forming the metal film, the metal film may be formed by vapor deposition on the base material, or the base material and the metal film may be attached and formed via an adhesive. Further, a commercially available base material with a metal film on which a metal film is formed may be used.

Examples of the method of applying the pressure-sensitive adhesive composition on the surface of the metal film in the step (1) include a spin coating method, a spray coating method, a bar coating method, a knife coating method, a roll coating method, a blade coating method, and a die coating method. Examples include the method and the gravure coat method.

The step (2) is a step of drying the coating film formed in the step (1), and the drying conditions are a temperature of 80 ° C. to 150 ° C. for 30 seconds to 5 minutes (preferably 40 seconds to 3 minutes). , More preferably 45 seconds to 2 minutes), and then to dry.
The pressure-sensitive adhesive layer can be formed on the surface of the metal film through the step (2).
In addition, in order to complete the cross-linking in the pressure-sensitive adhesive layer, it is preferable to go through a seasoning step of holding for a certain period (for example, about 1 to 14 days).

Through the above process, an adhesive sheet having a structure similar to that of the adhesive sheet 1a shown in FIG. 1A can be manufactured.
Further, after that, the peeling-treated surface of the peeling sheet may be further laminated on the surface of the formed pressure-sensitive adhesive layer to obtain a pressure-sensitive adhesive sheet having a structure similar to that of the pressure-sensitive adhesive sheet 1c shown in FIG. 1 (c).

In the double-sided pressure-sensitive adhesive sheet having a structure similar to that of the pressure-sensitive adhesive sheet 1b shown in FIG. 1 (b), a pressure-sensitive adhesive layer is formed on one of the metal films through the above steps (1) and (2). It can also be produced by forming an adhesive layer on the other metal film in the same manner. When the pressure-sensitive adhesive layer is formed on the metal film, the peel-off treated surface of the release sheet is further laminated on the surface of the pressure-sensitive adhesive layer to form a structure similar to the pressure-sensitive adhesive sheet 1d shown in FIG. 1 (d). A double-sided adhesive sheet having the above can also be manufactured.

The pressure-sensitive adhesive sheet according to one aspect of the present invention can be produced in addition to the methods having the above-mentioned steps (1) and (2).
For example, a pressure-sensitive adhesive composition is applied on the peel-processed surface of the release sheet to form a coating film, the coating film is dried to form a pressure-sensitive adhesive layer, and then the surface of the pressure-sensitive adhesive layer is made of metal. It can also be produced by attaching it to the metal film of the base material on which the film is formed.
In this manufacturing method, the coating method and the drying conditions of the coating film are as described above.

[Characteristics and applications of adhesive sheets]
The pressure-sensitive adhesive sheet of one aspect of the present invention is suitable for sticking to soda glass, and effectively suppresses so-called "evaporation skipping" in which at least a part of a metal film is oxidized and deteriorated by moisture in the atmosphere. can do.
An adhesive sheet according to one aspect of the present invention is attached to a non-tin surface or a tin surface of a float glass plate conforming to the standard according to JIS R3202: 2011, and allowed to stand in a high temperature and high humidity environment at 85 ° C. and a relative humidity of 85%. It is preferable that the vapor deposition skipping does not occur even after 96 hours have passed, more preferably the vapor deposition skipping does not occur even after 168 hours, and further preferably no vapor deposition skipping occurs even after 240 hours have passed. It is even more preferable that the vapor deposition skip does not occur even after 480 hours have passed.

The pressure-sensitive adhesive sheet of the present invention is used for sticking to soda glass, but in view of the above-mentioned characteristics of the present invention, it is preferable to use it for sticking soda glass to a non-tin surface.
The use of the adhesive sheet according to one aspect of the present invention is not particularly limited, and for example, it is used as a decorative label or display label attached to the surface of soda glass, a falsification prevention sheet, a conductive sheet for imparting conductivity, and the like. Can be applied to.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
Moreover, each physical property value is a value measured by the method shown below.

[Mass average molecular weight (Mw)]
It was measured under the following conditions using a gel permeation chromatograph device (manufactured by Tosoh Corporation, product name "HLC-8020"), and the value measured in terms of standard polystyrene was used.
(Measurement condition)
-Column: "TSK guard volume HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL" and "TSK gel G1000HXL" are connected in sequence (all manufactured by Tosoh Corporation).
-Column temperature: 40 ° C
・ Developing solvent: tetrahydrofuran ・ Flow rate: 1.0 mL / min

[Softening point]
Measured according to JIS K2531.

Manufacturing example 1
(Preparation of Adhesive Composition (1))
A pressure-sensitive adhesive composition (1) having an active ingredient concentration of 30% by mass was prepared by adding the components and blending amounts shown below and diluting with ethyl acetate.
"Acrylic copolymer (A-i)" (the content ratio of the constituent unit is n-butyl acrylate (BA) / acrylic acid (AAc) = 90.0 / 10.0 (mass%). Polymer, Mw = 470,000): 100 parts by mass (active ingredient ratio)
-"Toluene diisocyanate (TDI)" (product name "Coronate L", manufactured by Tosoh Corporation): 2.0 parts by mass (active ingredient ratio)

Manufacturing example 2
(Preparation of Adhesive Composition (2))
A pressure-sensitive adhesive composition (2) having an active ingredient concentration of 35% by mass was prepared by adding the following components and blending amounts and diluting with ethyl acetate.
-"Acrylic copolymer (A-ii)" (content ratio of constituent units is n-butyl acrylate (BA) / vinyl acetate (VAc) / acrylic acid (AAc) = 90.0 / 5.0 / 5.0 (% by mass) copolymer, Mw = 350,000): 100 parts by mass (active ingredient ratio)
-"Toluene diisocyanate (TDI)" (product name "Coronate L", manufactured by Tosoh Corporation): 1.0 part by mass (active ingredient ratio)

Manufacturing example 3
(Preparation of Adhesive Composition (3))
A pressure-sensitive adhesive composition (3) having an active ingredient concentration of 35% by mass was prepared by adding the following components and blending amounts and diluting with ethyl acetate.
"Acrylic copolymer (A-iii)" (content ratio of constituent units is n-butyl acrylate (BA) / 2-ethylhexyl acrylate (2EHA) / acrylic acid (AAc) / 2-hydroxyethyl acrylate ( 2HEA) = 56.0 / 40.0 / 3.5 / 0.5 (mass%) copolymer, Mw = 480,000): 100 parts by mass (active ingredient ratio)
-"Toluene diisocyanate (TDI)" (product name "Coronate L", manufactured by Tosoh Corporation): 1.0 part by mass (active ingredient ratio)

Manufacturing example 4
(1) Synthesis of linear urethane prepolymer (Ure) Isophorone diisocyanate is added to 100 parts by mass (active component ratio) of a polycarbonate diol having a mass average molecular weight (Mw) of 1,000 in a reaction vessel under a nitrogen atmosphere. The equivalent ratio of the hydroxyl group of the polycarbonate diol to the isocyanate group of the isophorone diisocyanate is 1/1. Further, 160 parts by mass of toluene is added, and the isocyanate group concentration is theoretically determined while stirring the mixture under a nitrogen atmosphere. The reaction was carried out at 80 ° C. for 6 hours or more until the amount was reached.
Then, a solution obtained by diluting 1.44 parts by mass (active component ratio) of 2-hydroxyethyl methacrylate (HEMA) with 30 parts by mass of toluene was added, and the isocyanate groups at both ends disappeared for another 6 hours at 80 ° C. The reaction was carried out to obtain a linear urethane prepolymer (Ure) having a mass average molecular weight (Mw) of 29000.
(2) Synthesis of acrylic urethane resin (i) In a reaction vessel under a nitrogen atmosphere, 45.0 parts by mass (active ingredient ratio) of the linear urethane prepolymer (Ure) obtained in (1) above, methyl methacrylate ( MMA) 53.2 parts by mass (active ingredient ratio), 2-hydroxyethyl methacrylate (HEMA) 1.8 parts by mass (active ingredient ratio) and 22.5 parts by mass of toluene were added, and the temperature was raised to 105 ° C. with stirring. bottom. Then, in the reaction vessel, a solution obtained by further diluting 1.0 part by mass (active ingredient ratio) of the radical initiator (manufactured by Nippon Finechem Co., Ltd., product name "ABN-E") with 94.5 parts by mass of toluene was added. The mixture was added dropwise over 4 hours while maintaining the temperature at 105 ° C. After completion of dropping the solution, the reaction was carried out at 105 ° C. for 6 hours to obtain a solution of an acrylic urethane resin (i) having a mass average molecular weight (Mw) of 105,000.
(3) Preparation of Adhesive Composition (4) A pressure-sensitive adhesive composition (4) having an active ingredient concentration of 25% by mass was prepared by adding the following components and blending amounts and diluting with toluene.
-"Acrylic urethane resin (i)" (resin obtained through the above (1) and (2), the content ratio of the constituent units is Ure / MMA / HEMA = 45.0 / 53.2 / 1.8 (Mass%) copolymer, Mw = 105,000): 100 parts by mass (active component ratio)
-"Hexamethylene diisocyanate (HMDI)" (product name "Coronate HL", manufactured by Tosoh Corporation): 2.0 parts by mass (active ingredient ratio)

Production example 5
(Preparation of Adhesive Composition (5))
A pressure-sensitive adhesive composition (5) having an active ingredient concentration of 30% by mass was prepared by adding the components and blending amounts shown below and diluting with ethyl acetate.
-Acrylic copolymer (ii) (content ratio of constituent units is n-butyl acrylate (BA) / methyl methacrylate (MMA) / vinyl acetate (VAc) / 2-hydroxyethyl acrylate (2HEA) = 80.0 Copolymer of /10.0 / 9.0 / 1.0 (% by mass), Mw = 600,000): 100 parts by mass (active ingredient ratio)
-"Trimethylolpropane xylene xylene isocyanate (XDI)" (product name "Takenate D-110N", manufactured by Mitsui Chemicals, Inc.): 1.6 parts by mass (active ingredient ratio)
-"Hydrogen rosin resin" (product name "KE-359", manufactured by Arakawa Chemical Industry Co., Ltd., softening point = 94 to 104 ° C): 25 parts by mass (active ingredient ratio)

Examples 1-3, Comparative Examples 1-2
(Making an adhesive sheet)
PET film with aluminum vapor deposition film (manufactured by Toray Film Processing Co., Ltd., product name "Metal Me", thickness: 50 μm, aluminum film, which is a metal film, is formed by vapor deposition on the PET film, which is the base material, to a thickness of 30 to 50 nm. A pressure-sensitive adhesive composition of the type shown in Table 1 was applied onto the surface of the aluminum-deposited surface of the laminated body) to form a coating film, and the coating film was applied at 100 ° C. (110 ° C. only in Comparative Example 1) at 2 ° C. It was dried for a minute to form a pressure-sensitive adhesive layer having a thickness of 10 μm.
Then, on the exposed surface of the formed adhesive layer, a release sheet (manufactured by Lintec Corporation, product name "SP-PET38131", thickness: 38 μm, polyethylene terephthalate (PET) film whose surface has been subjected to silicone release treatment). A pressure-sensitive adhesive sheet having the same structure as the pressure-sensitive adhesive sheet 1c shown in FIG. 1C was produced by laminating the peeling-treated surfaces of the above.

The pressure-sensitive adhesive sheets produced in Examples and Comparative Examples were evaluated for their effect of suppressing vapor deposition skipping based on the following methods. The evaluation results are shown in Table 2.
[Evaluation of the effect of suppressing vapor deposition skipping]
The pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples were cut into squares having a side of 25 mm and used as test samples. The release sheet of the test sample was removed, and the exposed surface of the pressure-sensitive adhesive layer was attached to the non-tin surface or tin surface of a float glass plate conforming to JIS R3202: 2011 at 85 ° C. and a relative humidity of 85. The state of the aluminum film of the test sample after 24 hours, 96 hours, 168 hours, 240 hours, and 480 hours under a high temperature and high humidity environment of% was visually observed through a float glass plate. The presence or absence of vapor deposition skipping was evaluated according to the following criteria.
-A: No vapor deposition skipping was observed.
-F: Thin-film deposition skipping was observed.

From Table 2, the pressure-sensitive adhesive sheets prepared in Examples 1 to 3 showed a high effect of suppressing vapor deposition skipping even when left to stand in a high-temperature and high-humidity environment for 480 hours or more. On the other hand, the pressure-sensitive adhesive sheets prepared in Comparative Examples 1 and 2 were left to stand for 240 hours in a high-temperature and high-humidity environment, resulting in thin-film deposition skipping.

1a, 1b, 1c, 1d Adhesive sheet 11 Base material 12, 12a, 12b Metal film 13, 13a, 13b Adhesive layer 14, 14a, 14b Release sheet

Claims (7)

An adhesive sheet having a base material, a metal film, and an adhesive layer laminated on the surface of the metal film.
The pressure-sensitive adhesive layer contains an acrylic copolymer (A) and a cross-linking agent (B) having a structural unit (a1) derived from an alkyl (meth) acrylate and a structural unit (a2) derived from a carboxy group-containing monomer. A layer formed from the pressure-sensitive adhesive composition,
The content of the constituent unit (a2) is 3.0% by mass or more with respect to the total amount of the constituent units of the acrylic copolymer (A).
The content of the cross-linking agent (B) is 0.10 parts by mass or more with respect to 100 parts by mass of the total amount of the acrylic copolymer (A).
Adhesive sheet used for sticking to soda glass. The pressure-sensitive adhesive sheet according to claim 1, wherein the metal film is colored. The pressure-sensitive adhesive sheet according to claim 2, wherein the metal film contains a metal or a metal compound selected from aluminum, chromium, nickel, gold, platinum, silver, tin, copper, iron, palladium, titanium oxide, and titanium nitride. The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive layer has a thickness of 1 to 100 μm. Any of claims 1 to 4, wherein the content of the metal inactivating agent contained in the pressure-sensitive adhesive composition is less than 1 part by mass with respect to 100 parts by mass of the total amount of the acrylic copolymer (A). The adhesive sheet described in item 1. The adhesive sheet according to any one of claims 1 to 5, which is used for attaching soda glass to a non-tin surface. The method for producing an adhesive sheet according to any one of claims 1 to 6.
A method for producing an adhesive sheet, which comprises the following steps (1) and (2).
-Step (1): A step of applying the pressure-sensitive adhesive composition to the surface of a metal film provided on a base material to form a coating film.
-Step (2): A step of drying the coating film.

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