JP5116214B2 - Adhesive sheets - Google Patents

Description

  The present invention relates to pressure-sensitive adhesive sheets, and more specifically, pressure-sensitive adhesive sheets having high adhesiveness, excellent terminal peeling prevention, a small amount of remaining organic solvent, and less occurrence of fogging phenomenon. (Adhesive tape, adhesive sheet, adhesive film, etc.)

  The water-dispersed acrylic pressure-sensitive adhesive using a water-dispersed acrylic polymer is desirable for environmental hygiene because it does not use an organic solvent as a solvent unlike the solvent-type acrylic pressure-sensitive adhesive. It has the advantage which is excellent also from a viewpoint (refer nonpatent literature 1). However, in the pressure-sensitive adhesive layer using an acrylic pressure-sensitive adhesive, the acrylic polymer has low adhesiveness and terminal peeling resistance (characteristic that the end portion is difficult to peel off after being attached to the adherend) and is expressed. For this reason, the use of an emulsion containing a tackifying resin enhances adhesion and terminal peeling prevention. However, an emulsion containing a tackifier resin may use an organic solvent in the production process for the purpose of reducing the melt viscosity or melt viscosity of the tackifier resin (see Patent Document 1). In order to produce an emulsion containing a tackifying resin without using an organic solvent, the emulsion must be emulsified under a high temperature and a high pressure. With a resin having a high softening temperature, the method is very difficult. In many cases, the type and amount of emulsifier used are greatly limited. As described above, in order to satisfy the manufacturing workability and the adhesive property, the tackifier resin may be melted using an organic solvent. When an organic solvent is used when producing an emulsion containing a tackifying resin, the organic solvent is usually distilled off under reduced pressure, but there is a problem that the organic solvent remains in a trace amount in the final product.

  In addition, the pressure-sensitive adhesive tape made by adding a tackifying resin is a so-called “fogging” in which volatile components in the pressure-sensitive adhesive tape adhere to the windshield and the like when used as an automobile interior material for a long period of time. The phenomenon was seen and became a problem.

JP 2002-285137 A

“Adhesive Handbook”, 2nd edition, Japan Adhesive Tape Industry Association, October 12, 1995, p. 150-156

Accordingly, an object of the present invention is to provide pressure-sensitive adhesive sheets having high adhesiveness, excellent terminal peeling prevention properties, and a small amount of remaining organic solvent.
Another object of the present invention is to provide pressure-sensitive adhesive sheets in which occurrence of fogging phenomenon is reduced.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors have reduced the content of the tackifying resin or reduced the thickness of the pressure-sensitive adhesive layer, so that desired adhesiveness to various adherends can be obtained. Focusing on the fact that residual organic solvent and fogging phenomenon occur from the tackifying resin because it can no longer be satisfied, effectively reducing the content without reducing the performance improvement effect of the tackifying resin I found a method that can be made. Specifically, the content of the tackifying resin as a whole pressure-sensitive adhesive sheet can be reduced by forming a pressure-sensitive adhesive layer containing a tackifying resin on a support via a specific polymer layer. And it discovered that the performance improvement effect by tackifying resin can be hold | maintained effectively. Thus, by providing a pressure-sensitive adhesive layer containing a tackifying resin only on the surface layer of the pressure-sensitive adhesive sheet that comes into contact with the adherend, and forming the lower layer portion only with a polymer layer not containing the tackifying resin, the pressure-sensitive adhesive It was found that the residual amount of the organic solvent in the pressure-sensitive adhesive sheets can be reduced and the occurrence of fogging phenomenon can be reduced while maintaining the adhesiveness of the layer and the terminal peeling prevention property at an excellent level. The present invention has been completed based on these findings.

（式（１）において、Ｒ ¹ は水素原子又はメチル基、Ｒ ² はアルキル基を示す。）
さらに、前記粘着シート類では、前記アクリル系重合体を構成するモノマー成分全量に対する前記（メタ）アクリル酸アルキルエステルの割合が、８０重量％以上であることが好ましい。
さらに、前記粘着シート類では、前記（メタ）アクリル酸アルキルエステルは、アクリル酸ブチル単独、またはアクリル酸ブチルとアクリル酸２−エチルヘキシルの組み合わせであり、アクリル酸ブチルとアクリル酸２−エチルヘキシルとの割合が、アクリル酸２−エチルヘキシル／アクリル酸ブチル（重量比）＝０／１００〜５５／４５であってもよい。 That is, the present invention is a pressure-sensitive adhesive sheet having a structure in which a pressure-sensitive adhesive layer is formed on at least one surface of a support, and contains a water-dispersed acrylic polymer on at least one surface of the support. A polymer layer made of a polymer composition, a water-dispersed acrylic polymer, and an adhesive layer made of a water-dispersed acrylic pressure-sensitive adhesive containing an emulsion containing a tackifying resin are formed in this order. The monomer component constituting the acrylic polymer in the water-dispersed acrylic polymer is mainly composed of (meth) acrylic acid alkyl ester, and the (meth) acrylic acid alkyl ester is represented by the following formula (1). an acrylic compound, in the following formula (1), R ² is an alkyl group having a carbon number of 2 to 14, an emulsion containing the tackifier resin, viscous Was dissolved tackifying resin in an organic solvent, and an emulsion containing a tackifying resin prepared by emulsifying, adhesive reflectance by the fogging test in accordance with German Industrial Standard DIN75201 is equal to or less than 70% Provide sheets.

(In Formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group.)
Furthermore, in the pressure-sensitive adhesive sheets, the ratio of the alkyl (meth) acrylate to the total amount of monomer components constituting the acrylic polymer is preferably 80% by weight or more.
Further, in the pressure-sensitive adhesive sheets, the (meth) acrylic acid alkyl ester is butyl acrylate alone or a combination of butyl acrylate and 2-ethylhexyl acrylate, and a ratio of butyl acrylate to 2-ethylhexyl acrylate. However, 2-ethylhexyl acrylate / butyl acrylate (weight ratio) = 0/100 to 55/45 may be used.

In the sheets, the pressure-sensitive adhesive layer preferably has a thickness of 2 to 50 μm.
Furthermore, in the pressure-sensitive adhesive sheets, the tackifying resin is at least one tackifying resin selected from the group consisting of a rosin ester resin, a terpene tackifying resin, a hydrocarbon tackifying resin, and a phenol tackifying resin. It may be.
Furthermore, in the pressure-sensitive adhesive sheets, the organic solvent may be an alicyclic hydrocarbon organic solvent.
Further, the pressure-sensitive adhesive sheets preferably have an organic solvent residual amount of 10 μg / g or less after heating at 150 ° C. for 30 minutes.
Furthermore, the pressure-sensitive adhesive sheets may have a configuration in which a tackifying resin-containing pressure-sensitive adhesive layer is formed on both surfaces of a base material as a support via a polymer layer.
Furthermore, the pressure-sensitive adhesive sheets have a configuration in which the tackifying resin-containing pressure-sensitive adhesive layer on either side is protected by a release liner whose both surfaces are release surfaces, and further, on the other side The tackifier resin-containing pressure-sensitive adhesive layer may have a configuration protected by the other release surface of the release liner by winding the pressure-sensitive adhesive sheet in a roll shape.

  The pressure-sensitive adhesive sheets of the present invention can be suitably used for fixing automobile materials or residential materials.

  According to the pressure-sensitive adhesive sheets of the present invention, the adhesive sheet has high adhesiveness and excellent terminal peeling resistance, and the remaining amount of the organic solvent is small. Furthermore, the occurrence of fogging phenomenon can be reduced. Therefore, it is suitable as pressure-sensitive adhesive sheets used for fixing automobile materials or residential materials.

  Embodiments of the present invention will be described below in detail with reference to the drawings as necessary. In addition, the same code | symbol may be attached | subjected to the same member, a site | part, etc.

  As shown in FIG. 1, the pressure-sensitive adhesive sheet of the present invention is a water-dispersed acrylic type containing a water-dispersed acrylic polymer and an emulsion containing a tackifying resin on at least one surface of a support. A pressure-sensitive adhesive layer (sometimes referred to as “tackifying resin-containing pressure-sensitive adhesive layer”) contains a water-dispersed acrylic polymer and a polymer layer made of a polymer composition not containing a tackifying resin. And has a formed configuration. In this way, the pressure-sensitive adhesive sheets are such that the tackifying resin-containing pressure-sensitive adhesive layer serving as the pressure-sensitive adhesive surface is formed on the support via the polymer layer, so that the entire tackifying resin-containing pressure-sensitive adhesive layer and polymer layer are formed. Even if the thickness of the tackifying resin-containing pressure-sensitive adhesive layer is reduced by maintaining the thickness of the conventional or normal pressure-sensitive adhesive layer, the pressure-sensitive adhesive sheets have high adhesiveness and excellent terminal peeling prevention properties. It can be demonstrated. Therefore, the thickness of the tackifying resin-containing pressure-sensitive adhesive layer can be reduced to a minimum thickness within a range in which the pressure-sensitive adhesive sheets can ensure high adhesion and excellent terminal peeling prevention properties. Therefore, the pressure-sensitive adhesive sheets of the present invention can effectively reduce the residual amount of the organic solvent while ensuring high adhesion and excellent terminal peeling prevention property, and further reduce the occurrence of fogging phenomenon. Can do.

  Fig.1 (a)-(f) is a schematic sectional drawing which respectively shows the example of the adhesive sheets of this invention. In FIG. 1, 11 to 16 are pressure-sensitive adhesive sheets, 2 is a base material, 3 is a polymer layer, 4 is a tackifying resin-containing pressure-sensitive adhesive layer, and 5 is a release liner. The pressure-sensitive adhesive sheets 11 shown in FIG. 1A have a configuration in which a tackifying resin-containing pressure-sensitive adhesive layer 4 is formed on both surfaces of a base material 2 as a support via a polymer layer 3. The tackifying resin-containing pressure-sensitive adhesive layers 4 on both sides each have a structure protected by a release liner 5 having only one side as a release surface. Moreover, the pressure-sensitive adhesive sheets 12 shown in FIG. 1B have a configuration in which a tackifying resin-containing pressure-sensitive adhesive layer 4 is formed on both surfaces of a base material 2 as a support via a polymer layer 3. And the tackifying resin-containing pressure-sensitive adhesive layer 4 on either side has a structure protected by a release liner 5 whose both surfaces are release surfaces, and the other side is tackified. The resin-containing pressure-sensitive adhesive layer 4 can be configured to be protected by the other release surface of the release liner 5 by winding the pressure-sensitive adhesive sheet 12 in a roll shape.

  Moreover, the pressure-sensitive adhesive sheets 13 shown in FIG. 1C have a configuration in which a tackifying resin-containing pressure-sensitive adhesive layer 4 is formed on one side of a base material 2 as a support via a polymer layer 3. The tackifying resin-containing pressure-sensitive adhesive layer 4 has a structure protected by a release liner 5 having only one side as a release surface. The adhesive sheet 14 shown in FIG. 1 (d) has a configuration in which a tackifying resin-containing adhesive layer 4 is formed on one side of a substrate 2 as a support via a polymer layer 3. And the back surface of the base material 2 as a support is a release surface, and the tackifying resin-containing pressure-sensitive adhesive layer 4 is formed by rolling the pressure-sensitive adhesive sheet 14 in a roll shape, thereby forming the base material 2 as a support. It can be set as the structure protected by the peeling surface formed in the back surface.

  Furthermore, the pressure-sensitive adhesive sheet 15 shown in FIG. 1 (e) has a polymer layer 3 on one side of the release liner 5 as a support (one side on the release surface side of the release liner where only one side is the release surface). The tackifying resin-containing pressure-sensitive adhesive layer 4 has a structure formed through the adhesive layer, and the tackifying resin-containing pressure-sensitive adhesive layer 4 is protected by the release liner 5 having only one side as a release surface. It has a configuration. A pressure-sensitive adhesive sheet 16 shown in FIG. 1 (f) is a pressure-sensitive adhesive containing a tackifier resin via a polymer layer 3 on one side of a release liner 5 (a release liner having both sides as release surfaces) as a support. The tackifying resin-containing pressure-sensitive adhesive layer 4 has a configuration in which the layer 4 is formed, and the other release surface of the release liner 5 as a support by winding the pressure-sensitive adhesive sheet 16 in a roll shape. It can be set as the structure protected by. In FIG. 1 (f), the pressure-sensitive adhesive sheets have a layer structure of release liner / polymer layer / tackifying resin-containing pressure-sensitive adhesive layer whose both surfaces are release surfaces, but the polymer layer / tackification Resin-containing pressure-sensitive adhesive layer / Same as pressure-sensitive adhesive sheets having a release liner layer structure where both surfaces are release surfaces.

  Thus, the pressure-sensitive adhesive sheets of the present invention may be pressure-sensitive adhesive sheets having a base material (pressure-sensitive adhesive sheets with a base material), or pressure-sensitive adhesive sheets having no base material (base material-less). Adhesive sheets) may be used. The pressure-sensitive adhesive sheets may be either double-sided pressure-sensitive adhesive sheets whose both surfaces are pressure-sensitive adhesive surfaces or pressure-sensitive adhesive sheets whose only one surface is a pressure-sensitive adhesive surface. When the pressure-sensitive adhesive sheet is a substrate-less pressure-sensitive adhesive sheet, a support that can exhibit releasability from the pressure-sensitive adhesive layer (for example, a release liner) can be used as the support. .

[Adhesive layer containing tackifying resin]
The tackifying resin-containing pressure-sensitive adhesive layer is a water-dispersed acrylic pressure-sensitive adhesive containing a water-dispersed acrylic polymer and an emulsion containing a tackifying resin (sometimes referred to as “tackifying resin-containing emulsion”). It is a pressure-sensitive adhesive layer.

（式（１）において、Ｒ¹は水素原子又はメチル基、Ｒ²はアルキル基を示す。） (Water-dispersed acrylic polymer)
In the tackifying resin-containing pressure-sensitive adhesive layer, the water-dispersed acrylic polymer is an emulsion-based acrylic polymer composition in which the acrylic polymer is dispersed in water. The acrylic polymer is used as a base polymer of the pressure-sensitive adhesive (basic component of the pressure-sensitive adhesive). In the acrylic polymer, (meth) acrylic acid alkyl ester (acrylic acid alkyl ester, methacrylic acid alkyl ester) is used as the main constituent monomer component (monomer main component). As said (meth) acrylic-acid alkylester, the acryl-type compound represented by following formula (1) can be used suitably, for example.

(In Formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group.)

In the formula (1), R ¹ is a hydrogen atom or a methyl group. R ² is an alkyl group. Specifically, examples of the alkyl group for R ² include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, isoamyl group, and neopentyl. Group, hexyl group, heptyl group, octyl group, isooctyl group, 2-ethylhexyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl And alkyl groups having 1 to 20 carbon atoms such as a group, octadecyl group, nonadecyl group, and eicosyl group. As the alkyl group for R ² , an alkyl group having 2 to 14 carbon atoms is preferable, and an alkyl group having 2 to 10 carbon atoms (particularly, a butyl group and a 2-ethylhexyl group) is preferable.

  Specifically, examples of the (meth) acrylic acid alkyl ester include, for example, butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, ( Pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, (Meth) acrylic acid nonyl, (meth) acrylic acid isononyl, (meth) acrylic acid decyl, (meth) acrylic acid isodecyl, (meth) acrylic acid undecyl, (meth) acrylic acid dodecyl etc. are mentioned.

  The (meth) acrylic acid alkyl ester can be used alone or in combination of two or more. As (meth) acrylic acid alkyl ester, for example, butyl acrylate may be used alone, or butyl acrylate and 2-ethylhexyl acrylate may be used in combination. In addition, as a (meth) acrylic acid alkyl ester, when butyl acrylate is used alone or in combination with butyl acrylate and 2-ethylhexyl acrylate, the ratio between butyl acrylate and 2-ethylhexyl acrylate is as follows: Although not particularly limited, for example, it can be selected from the range of 2-ethylhexyl acrylate / butyl acrylate (weight ratio) = 0/100 to 55/45 (preferably 5/95 to 60/40).

  As the monomer component constituting the acrylic polymer, other monomer components that can be copolymerized with (meth) acrylic acid alkyl ester (“copolymerizable monomer”) can be used as long as (meth) acrylic acid alkyl ester is the main monomer component. May be referred to as “components”). In addition, as a ratio of the (meth) acrylic acid alkyl ester to the total amount of monomer components constituting the acrylic polymer, it is 80% by weight or more (for example, 80 to 99.8% by weight), preferably 85% by weight or more (for example, 85 to 99.5% by weight), more preferably 90% or more (90 to 99% by weight).

  As the copolymerizable monomer component, it can be used for introducing a crosslinking point into the acrylic polymer or for increasing the cohesive force of the acrylic polymer. The copolymerizable monomer components can be used alone or in combination of two or more.

  Specifically, as the copolymerizable monomer component, a functional group-containing monomer component (particularly, heat for introducing a crosslinking point that is thermally crosslinked to the acrylic polymer) is introduced in order to introduce a crosslinking point into the acrylic polymer. Crosslinkable functional group-containing monomer component) can be used. By using the functional group-containing monomer component, it is possible to improve the adhesion to the adherend. Such a functional group-containing monomer component is not particularly limited as long as it is a monomer component that can be copolymerized with a (meth) acrylic acid alkyl ester and has a functional group that becomes a crosslinking point. (Meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, isocrotonic acid and other carboxyl group-containing monomers or acid anhydrides thereof (maleic anhydride, itaconic anhydride, etc.); (meth) acrylic acid 2-hydroxy Hydroxyalkyl (meth) acrylates such as ethyl, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, etc., and hydroxyl-containing monomers such as vinyl alcohol and allyl alcohol; (meth) acrylamide, N , N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, -Amide monomers such as methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide; aminoethyl (meth) acrylate, (meth) Amino group-containing monomers such as N, N-dimethylaminoethyl acrylate and t-butylaminoethyl (meth) acrylate; Epoxy group-containing monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate; acrylonitrile; Cyano-containing monomers such as methacrylonitrile; N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinyl Roll, N- vinylimidazole, N- vinyloxazole, N- vinyl morpholine, N- vinyl caprolactam, such a monomer having a nitrogen atom-containing ring such as N- (meth) acryloyl morpholine. As the functional group-containing monomer component, a carboxyl group-containing monomer such as acrylic acid or an acid anhydride thereof can be suitably used.

  The amount of the functional group-containing monomer component used is, for example, (meth) acrylic acid alkyl ester as a monomer main component: 12 parts by weight or less (for example, 0.5 to 12 parts by weight, preferably 1 with respect to 100 parts by weight) -8 parts by weight).

  Further, as the copolymerizable monomer component, other copolymerizable monomer components can be used in order to increase the cohesive strength of the acrylic polymer. Other copolymerizable monomer components include, for example, vinyl ester monomers such as vinyl acetate and vinyl propionate; styrene monomers such as styrene, substituted styrene (α-methylstyrene, etc.) and vinyltoluene; (meth) acrylic acid Non-aromatic ring-containing (meth) acrylate esters such as cycloalkyl esters [cyclohexyl (meth) acrylate, cyclopentyl di (meth) acrylate, etc.] and isobornyl (meth) acrylate; (meth) acrylate aryl esters [ Fragrances such as (meth) acrylic acid phenyl etc.], (meth) acrylic acid aryloxyalkyl esters [(meth) acrylic acid phenoxyethyl etc.] and (meth) acrylic acid arylalkyl esters [(meth) acrylic acid benzyl ester] Aromatic ring content (meta) Crylic acid esters; Olefin-based monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; Vinyl chloride, vinylidene chloride; Isocyanate group-containing monomers such as 2- (meth) acryloyloxyethyl isocyanate; Methoxyethyl (meth) acrylate, ( Alkoxy group-containing monomers such as methacrylic acid ethoxyethyl; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether, 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) ) Acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate , Propylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol Multifunctional monomers such as tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin di (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, divinylbenzene, butyl di (meth) acrylate, hexyl di (meth) acrylate Etc.

  The water-dispersed acrylic polymer can be prepared by a known or conventional polymerization method (for example, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a polymerization method by ultraviolet irradiation, etc.) using the monomer component. . In the polymerization, various polymerization methods such as a general batch charging method (batch polymerization method) and a monomer dropping method (continuous dropping method, divided dropping method, etc.) can be employed. The polymerization temperature can be appropriately selected according to the type of monomer, the type of polymerization initiator, and the like, and can be selected from the range of 20 to 100 ° C., for example.

  As a polymerization initiator used at the time of superposition | polymerization, it can select suitably from well-known thru | or a usual polymerization initiator according to the kind of polymerization method. Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (2-amidinopropane) dihydro Chloride, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (N, N'-dimethyleneisobutylamidine), 2,2 '-Azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-methylbutyronitrile), 1, 1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2,4,4-trimethylpentane), dimethyl-2,2'-azobis (2-methylpropiyl) Azo polymerization initiators such as sulfonates; persulfates such as potassium persulfate and ammonium persulfate; benzoyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxybenzoate, dicumylper Start of peroxide polymerization of oxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, hydrogen peroxide, etc. Agents: Substituted ethane polymerization initiators such as phenyl-substituted ethanes; aromatic carbonyl compounds; redox initiators in combination with peroxides and reducing agents [for example, combinations of peroxides and ascorbic acid (hydrogen peroxide water And a combination of peroxide and iron (II) salt (hydrogen peroxide water and the like) (II) a combination with a salt), a redox polymerization initiator by a combination of a persulfate and sodium bisulfite, etc.] The polymerization initiators can be used alone or in combination of two or more. .

  The usage-amount of a polymerization initiator should just be a normal usage-amount, for example, can be selected from the range of about 0.005-1 weight part with respect to 100 weight part of all monomer components.

  In the polymerization, a chain transfer agent can be used to adjust the molecular weight. As the chain transfer agent, known or commonly used chain transfer agents can be used. For example, dodecanethiol (lauryl mercaptan), glycidyl mercaptan, 2-mercaptoethanol, mercaptoacetic acid, 2-ethylhexyl thioglycolate, 2,3- In addition to mercaptans such as dimethylcapto-1-propanol, α-methylstyrene dimer and the like can be mentioned. A chain transfer agent can be used individually or in combination of 2 or more types. The usage amount of the chain transfer agent may be a normal usage amount, and can be selected, for example, from a range of about 0.001 to 0.5 parts by weight with respect to 100 parts by weight of the total monomer components.

  Since the water-dispersed acrylic polymer has the form of an emulsion, the water-dispersed acrylic polymer is prepared using the emulsion-form polymer prepared by using the emulsion polymerization method as it is. Alternatively, a water-dispersed acrylic polymer may be prepared by dispersing an acrylic polymer prepared by using a polymerization method other than the emulsion polymerization method (for example, solution polymerization method) in water. Good. An emulsifier can be used during emulsion polymerization or when the acrylic polymer is dispersed in water. An emulsifier can be used individually or in combination of 2 or more types.

  Specifically, as the emulsifier, for example, any form of emulsifier may be used, but an anionic emulsifier and a nonionic emulsifier can be suitably used. Examples of the anionic emulsifier include alkyl sulfate anion emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, and potassium lauryl sulfate; polyoxyethylene alkyl ether sulfate anion emulsifiers such as sodium polyoxyethylene lauryl ether sulfate; Polyoxyethylene alkylphenyl ether sulfate-type anionic emulsifiers such as ammonium oxyethylene lauryl phenyl ether sulfate and sodium polyoxyethylene lauryl phenyl ether sulfate; Sulfonate-type anionic emulsifiers such as sodium dodecylbenzenesulfonate; Disodium lauryl sulfosuccinate And a sulfosuccinic acid type anionic emulsifier such as polyoxyethylene sulfosuccinate disodium lauryl. Nonionic emulsifiers include, for example, polyoxyethylene alkyl ether type nonionic emulsifiers such as polyoxyethylene lauryl ether; polyoxyethylene alkylphenyl ether type nonionic emulsifiers such as polyoxyethylene lauryl phenyl ether; polyoxyethylene fatty acids Nonionic emulsifiers such as esters and polyoxyethylene polyoxypropylene block polymers are listed.

  The amount of the emulsifier is not particularly limited as long as it is an amount that can prepare the acrylic polymer in the form of an emulsion. For example, the amount of the emulsifier is 0.2 to 10 with respect to the total amount of the acrylic polymer or the monomer component. It can be selected from the range of about wt% (preferably 0.5 to 5 wt%).

(Tackifying resin-containing emulsion)
In the tackifying resin-containing pressure-sensitive adhesive layer, the tackifying resin-containing emulsion is a tackifying resin composition in an emulsion form in which the tackifying resin is dispersed in water. The tackifying resin is not particularly limited. For example, rosin-based tackifying resin, terpene-based tackifying resin, hydrocarbon-based tackifying resin, phenol-based tackifying resin, ketone-based tackifying resin, epoxy-based tackifying resin, Examples thereof include polyamide-based tackifying resins and elastomer-based tackifying resins. Tackifying resins can be used alone or in combination of two or more.

  Specifically, as the rosin-based tackifying resin, for example, unmodified rosin (raw rosin) such as gum rosin, wood rosin, tall oil rosin, and hydrogenation, disproportionation, polymerization, etc. of these unmodified rosins. In addition to modified rosins (hydrogenated rosin, disproportionated rosin, polymerized rosin, and other chemically modified rosins), various rosin derivatives and the like can be mentioned. Examples of the rosin derivative include rosin ester compounds obtained by esterifying unmodified rosin with alcohols, and modified rosin esters obtained by esterifying modified rosins such as hydrogenated rosin, disproportionated rosin and polymerized rosin with alcohols. Rosin esters such as compounds; Unmodified rosin and modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.) modified with unsaturated fatty acids; Unsaturated fatty acid modified rosins; Rosin esters modified with unsaturated fatty acids Unsaturated rosin, modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.), unsaturated fatty acid modified rosins and unsaturated fatty acid modified rosin esters Rosin alcohols such as unmodified rosin, modified rosin and various rosin derivatives Oxazines (especially, rosin esters) and the like metal salts of.

  Examples of terpene-based tackifier resins include terpene resins such as α-pinene polymers, β-pinene polymers, dipentene polymers, and modified terpene resins (phenol-modified, aromatic-modified, hydrogenated-modified). And modified terpene resins such as terpene-phenol resins, styrene modified terpene resins, aromatic modified terpene resins, hydrogenated terpene resins, and the like.

  Examples of hydrocarbon-based tackifying resins include aliphatic hydrocarbon resins [olefins having 4 to 5 carbon atoms and dienes (olefins such as butene-1, isobutylene, pentene-1; butadiene, 1,3-pentadiene, isoprene). Polymers of aliphatic hydrocarbons such as diene etc.], aromatic hydrocarbon resins [vinyl group-containing aromatic hydrocarbons having 8 to 10 carbon atoms (styrene, vinyl toluene, α-methylstyrene) , Indene, methylindene, etc.)], and aliphatic cyclic hydrocarbon resins [so-called “C4 petroleum fraction” and “C5 petroleum fraction” after cyclization and dimerization and polymerization. Hydrocarbon resins, cyclic diene compounds (cyclopentadiene, dicyclopentadiene, ethylidene norbornene, dipentene, etc.) polymers or hydrogenated products thereof, Aromatic hydrocarbon resins, alicyclic hydrocarbon resins obtained by hydrogenating aromatic rings of aliphatic / aromatic petroleum resins, etc.], aliphatic / aromatic petroleum resins (styrene-olefin copolymers, etc.) And various hydrocarbon resins such as aliphatic / alicyclic petroleum resins, hydrogenated hydrocarbon resins, coumarone resins, coumarone indene resins, and the like.

  Examples of phenolic tackifier resins include condensates of various phenols with formaldehyde. Examples of the phenols include phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin and the like. Specifically, the phenolic tackifier resin includes, for example, an alkylphenolic resin, a xylene-formaldehyde resin, and the like. In addition, the phenolic tackifier resin includes resole obtained by addition reaction of the above phenols and formaldehyde with an alkali catalyst, novolak obtained by condensation reaction of the above phenols and formaldehyde with an acid catalyst, and rosin. A rosin phenol resin obtained by adding phenol to an acid (non-modified rosin, modified rosin, various rosin derivatives, etc.) with an acid catalyst and thermal polymerization can also be used.

  Examples of the ketone tackifying resin include condensates of ketones such as methyl ethyl ketone, methyl isobutyl ketone, acetophenone, cyclohexanone and methylcyclohexanone with formaldehyde.

  The tackifying resin-containing emulsion can be prepared by dispersing the tackifying resin in water. When the tackifying resin is dispersed in water, an emulsifier can be used. As such an emulsifier, one or two or more kinds of emulsifiers exemplified as the emulsifier used when preparing the water-dispersed acrylic polymer can be appropriately selected and used. Specifically, as the emulsifier, for example, any form of emulsifier may be used, but an anionic emulsifier and a nonionic emulsifier can be suitably used. Examples of the anionic emulsifier include alkyl sulfate anion emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, and potassium lauryl sulfate; polyoxyethylene alkyl ether sulfate anion emulsifiers such as sodium polyoxyethylene lauryl ether sulfate; Polyoxyethylene alkylphenyl ether sulfate-type anionic emulsifiers such as ammonium oxyethylene lauryl phenyl ether sulfate and sodium polyoxyethylene lauryl phenyl ether sulfate; Sulfonate-type anionic emulsifiers such as sodium dodecylbenzenesulfonate; Disodium lauryl sulfosuccinate And a sulfosuccinic acid type anionic emulsifier such as polyoxyethylene sulfosuccinate disodium lauryl. Nonionic emulsifiers include, for example, polyoxyethylene alkyl ether type nonionic emulsifiers such as polyoxyethylene lauryl ether; polyoxyethylene alkylphenyl ether type nonionic emulsifiers such as polyoxyethylene lauryl phenyl ether; polyoxyethylene fatty acids Nonionic emulsifiers such as esters and polyoxyethylene polyoxypropylene block polymers are listed.

  In addition, the emulsifier when preparing the water-dispersed acrylic polymer and the emulsifier when preparing the tackifier resin-containing emulsion may be either the same emulsifier or different emulsifiers. If it is an anionic emulsifier, the other is preferably an anionic emulsifier, and if one is a nonionic emulsifier, the other is also preferably a nonionic emulsifier.

  The amount of the emulsifier used is not particularly limited as long as it is an amount that can be used to prepare the tackifying resin in the form of an emulsion. For example, 0.2 to 10% by weight with respect to the total amount of the tackifying resin (solid content). % (Preferably 0.5 to 5% by weight).

  In preparing the tackifying resin in the form of an emulsion, an organic solvent is usually used to dissolve the tackifying resin. As such an organic solvent, an aromatic hydrocarbon-based organic solvent such as toluene is generally used, but a low-toxic alicyclic hydrocarbon-based organic solvent is used instead of the aromatic hydrocarbon-based organic solvent. When is used, the influence on the environment and the human body can be reduced. Therefore, as the tackifying resin-containing emulsion, a tackifying resin-containing emulsion prepared by dissolving the tackifying resin in an alicyclic hydrocarbon-based organic solvent and emulsifying it is preferable.

  Examples of such alicyclic hydrocarbon-based organic solvents include cyclohexanes (cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, alkyl group-containing cyclohexane such as methylethylcyclohexane, etc.), and other cyclohexanes. And cyclopentanes (such as cyclopentane and alkyl group-containing cyclopentane), cycloheptanes (such as cycloheptane and alkyl group-containing cycloheptane), and cyclooctanes (such as cyclooctane and alkyl group-containing cyclooctane).

  In addition, the organic solvent used in order to dissolve tackifying resin can be used individually or in combination of 2 or more types.

  Further, the amount of such an organic solvent used is not particularly limited, but may be any amount that can dissolve the tackifier resin and disperse it in water using an emulsifier as necessary. It is preferable that the amount used is minimal. It is important to remove the organic solvent as much as possible after preparing the tackifying resin-containing emulsion by a known or conventional removal method (for example, a vacuum distillation method or the like).

  As the tackifying resin-containing emulsion, the tackifying resin in the tackifying resin-containing emulsion is 10 to 100 parts by weight (preferably 15 to 100 parts by weight with respect to 100 parts by weight of the acrylic polymer in the water-dispersed acrylic polymer). 80 parts by weight, more preferably 20 to 60 parts by weight). The tackifying resin-containing emulsion is blended in a blending amount such that the tackifying resin in the tackifying resin-containing emulsion is less than 10 parts by weight with respect to 100 parts by weight of the acrylic polymer in the water-dispersed acrylic polymer. If it is, the addition effect of the tackifying resin is not sufficient, the target adhesive strength can not be obtained, the terminal peeling prevention property is lowered, on the other hand, the blending amount exceeds 100 parts by weight In this case, the residual amount of the organic solvent increases, and the adhesive strength may decrease due to poor compatibility with the acrylic polymer.

(Other ingredients)
A cross-linking agent may be used in the water-dispersed acrylic pressure-sensitive adhesive for forming the tackifying resin-containing pressure-sensitive adhesive layer, if necessary. The crosslinking agent is not particularly limited, and is a known or conventional crosslinking agent (for example, an isocyanate crosslinking agent, an epoxy crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, a melamine crosslinking agent, a peroxide crosslinking agent). , Urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, amine crosslinking agents, etc.). The crosslinking agent may be either an oil-soluble crosslinking agent or a water-soluble crosslinking agent. A crosslinking agent can be used individually or in combination of 2 or more types. The amount of the crosslinking agent used is not particularly limited. For example, the acrylic polymer in the water-dispersed acrylic polymer: 10 parts by weight or less (for example, 0.005 to 10 parts by weight, Preferably, it can select from the range of about 0.01-5 weight part).

  In addition, the water-dispersed acrylic pressure-sensitive adhesive for forming the tackifying resin-containing pressure-sensitive adhesive layer may contain other additives (for example, anti-aging agents, ultraviolet absorbers, antioxidants, light stabilizers) as necessary. Agents, release modifiers, plasticizers, softeners, fillers, colorants (pigments, dyes, etc.), surfactants, antistatic agents, etc.) and bases for adjusting the pH (Ammonia water or the like) or acid may be contained.

  The tackifying resin-containing pressure-sensitive adhesive layer is prepared by mixing or kneading the above components (water-dispersed acrylic polymer, tackifying resin-containing emulsion, as well as cross-linking agents and various additives as necessary) in predetermined amounts. It can form by apply | coating the water-dispersed acrylic adhesive prepared by this on a predetermined surface, and making it dry or harden | cure. A conventional coater (for example, a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, or a spray coater) can be used for applying the water-dispersed acrylic pressure-sensitive adhesive.

  The thickness of the tackifying resin-containing pressure-sensitive adhesive layer can be selected, for example, from the range of 2 to 150 μm (preferably 5 to 100 μm), and particularly preferably 2 to 50 μm (among others, 2 to 20 μm). is there. The thickness of the tackifying resin-containing pressure-sensitive adhesive layer is such that, in order to reduce the remaining amount of the organic solvent, the polymer layer by the polymer composition containing the water-dispersed acrylic polymer and not containing the tackifying resin is used. The thinner one is preferable than the thickness. In addition, if the thickness of the tackifying resin-containing pressure-sensitive adhesive layer is too thin, the adhesiveness of the pressure-sensitive adhesive sheets and the terminal peeling prevention property will decrease, so the thickness of the tackifying resin-containing pressure-sensitive adhesive layer will prevent adhesion and terminal peeling. Depending on the nature, it can be set appropriately so as to be as thin as possible.

[Polymer layer]
The polymer layer is a polymer layer made of a polymer composition containing a water-dispersed acrylic polymer and not containing a tackifying resin. As the water-dispersed acrylic polymer contained in the polymer composition for forming the polymer layer (sometimes referred to as “water-dispersed acrylic polymer for polymer layer”), the acrylic polymer is dispersed in water. An acrylic polymer composition in the form of an emulsion. The water-dispersed acrylic polymer for the polymer layer includes a water-dispersed acrylic polymer contained in the water-dispersed acrylic pressure-sensitive adhesive for forming the tackifying resin-containing pressure-sensitive adhesive layer (“water-dispersed type for pressure-sensitive adhesive layer”). One or two or more of the water-dispersed acrylic polymers exemplified in the section “sometimes referred to as an“ acrylic polymer ”” may be appropriately selected and used.

  The water-dispersed acrylic polymer for the polymer layer may be any of the water-dispersed acrylic polymer for the pressure-sensitive adhesive layer, the same water-dispersed acrylic polymer, or a different water-dispersed acrylic polymer. . The acrylic polymer and emulsifier in the water-dispersed acrylic polymer for the polymer layer may be the same as or different from the acrylic polymer and emulsifier in the water-dispersed acrylic polymer for the adhesive layer. It may be.

  Therefore, the polymer composition for forming the polymer layer corresponds to a composition obtained by removing the tackifying resin-containing emulsion from the water-dispersed acrylic pressure-sensitive adhesive for forming the tackifying resin-containing pressure-sensitive adhesive layer.

  The polymer layer is a water-dispersed acrylic polymer composition prepared by mixing or kneading a water-dispersible acrylic polymer, if necessary, with a predetermined amount of a crosslinking agent or various additives. The polymer composition) can be formed by applying on a predetermined surface and drying or curing. In the application of the polymer composition, a conventional coater (for example, a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, Spray coater or the like.

  The thickness of the polymer layer (thickness after drying) can be selected from the range of, for example, 2 to 150 μm (preferably 5 to 100 μm), and particularly preferably 20 to 150 μm (among them, 50 to 100 μm). It is. In addition, the thickness of a polymer layer can be suitably set according to the thickness of a tackifying resin containing adhesive layer. By increasing the thickness of the polymer layer, it is possible to reduce the thickness of the tackifying resin-containing pressure-sensitive adhesive layer.

  There are no particular restrictions on the thickness of the polymer layer and the thickness of the tackifier-resin-containing pressure-sensitive adhesive layer, such as a special condition (for example, the ratio of the thicknesses). The total thickness (total thickness after drying) of the pressure-sensitive adhesive layer is, for example, desirably 10 to 300 μm (preferably 50 to 150 μm).

[Support]
In the pressure-sensitive adhesive sheets of the present invention, a substrate or a release liner can be suitably used as the support. As described above, when the support is a base material, the pressure-sensitive adhesive sheets are pressure-sensitive adhesive sheets with a base material, and when the support is not a base material but a release liner, the pressure-sensitive adhesive sheets are base-less. Adhesive sheets. In addition, the support body is contacting the surface by the side of a polymer layer in the laminated body of a polymer layer and a tackifying resin containing adhesive layer. Accordingly, a release liner that protects only the surface of the tackifying resin-containing pressure-sensitive adhesive layer [for example, the release liner 5 in FIGS. 1 (a) to 1 (c) or the tackifying resin-containing pressure-sensitive adhesive layer 4 in FIG. 1 (e). The release liner 5 that protects the surface is not included in the support, but the release liner that protects only the surface of the polymer layer [for example, protects the surface of the polymer layer 3 in FIG. The release liner 5 and the like] and the release liner [for example, the release liner 5 and the like in FIG. 1 (f)] that protect the surfaces of both the polymer layer and the tackifying resin-containing pressure-sensitive adhesive layer are included in the support. Thus, the release liner as a support supports the laminate of the polymer layer and the tackifying resin-containing pressure-sensitive adhesive layer, and both the surface of the polymer layer or the polymer layer and the pressure-sensitive resin-containing pressure-sensitive adhesive layer. Can protect the surface.

  In the support, examples of the substrate include a polyolefin sheet or film (polyethylene sheet or film, polypropylene sheet or film, ethylene-propylene copolymer sheet or film, etc.), polyester sheet or film (polyethylene terephthalate). Sheet or film), vinyl chloride resin sheet or film, vinyl acetate resin sheet or film, polyimide resin sheet or film, polyamide resin sheet or film, fluororesin sheet or film, cellophane Plastic sheets or films such as Japanese paper, kraft paper, glassine paper, fine paper, synthetic paper, top coat paper, etc .; cotton fiber, sufu, manila hemp, pulp, rayon, acetate fiber, polyester Textile, polyvinyl alcohol fiber, polyamide fiber, polyolefin fiber and other natural fibers, semi-synthetic fibers or synthetic fiber fibrous materials such as single or mixed woven fabrics and non-woven fabrics; natural rubber, butyl rubber, etc. Examples include rubber sheets; foam sheets made of a foam made of polyurethane, polychloroprene rubber, etc .; metal foils such as aluminum foil and copper foil; and composites thereof. The plastic sheet or film may be either a non-stretching type or a stretching type (uniaxial stretching type or biaxial stretching type). The substrate may have a single layer form or may have a laminated form.

  In addition, for the base material, fillers (inorganic fillers, organic fillers, etc.), anti-aging agents, antioxidants, ultraviolet absorbers, lubricants, plasticizers, colorants (pigments, dyes, etc.) as necessary Various additives such as these may be blended.

  For the surface of the base material (particularly the surface on the polymer layer side), for example, appropriate known or conventional surface treatment such as physical treatment such as corona discharge treatment or plasma treatment, chemical treatment such as undercoating treatment or back treatment. May be given.

  Although the thickness of a base material can be suitably selected according to the objective, Generally, it is about 10-200 micrometers (preferably 20-100 micrometers).

(Release liner)
In the support, the release liner is not particularly limited and can be appropriately selected from known release liners. As the release liner, a substrate having a release treatment layer with a release treatment agent on at least one surface can be suitably used, and a fluorine-based polymer (for example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyfluoride) can be used. Low adhesive substrates made of vinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene / hexafluoropropylene copolymer, chlorofluoroethylene / vinylidene fluoride copolymer, etc., and nonpolar polymers (eg, polyethylene, polypropylene, etc.) A low-adhesive substrate made of an olefin resin or the like can also be used.

  As the base material of the release liner, a plastic sheet or a film is suitably used, but the paper, cloth, rubber sheet, foam sheet, metal foil, etc. exemplified as the base material as the support should also be used. Can do. The plastic sheet or film as the base material of the release liner is not particularly limited, and can be appropriately selected from, for example, the plastic sheets or films exemplified as the base material as the support.

  As the release treatment agent for forming the release treatment layer, a known or commonly used release treatment agent (silicone release treatment agent, fluorine release treatment agent, long-chain alkyl release treatment agent, etc.) can be used.

  The thickness of the base material or the release treatment layer in the release liner is not particularly limited, and can be appropriately selected according to the purpose. The total thickness of the release liner is, for example, preferably 15 μm or more, and more preferably 25 to 500 μm.

  In addition, the release liner which protects only the surface of the tackifying resin-containing pressure-sensitive adhesive layer can be appropriately selected from the exemplified release liners as the release liner as the support. The release liner that protects only the surface of the tackifying resin-containing pressure-sensitive adhesive layer and the release liner as the support may be a release liner having the same configuration or a release liner having a different configuration. .

[Adhesive sheets]
As described above, the pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer (sometimes referred to as a “layered pressure-sensitive adhesive layer”) by a laminate of a tackifying resin-containing pressure-sensitive adhesive layer and a polymer layer. While securing the thickness of the laminated pressure-sensitive adhesive layer as the thickness of the conventional or normal tackifying resin-containing pressure-sensitive adhesive layer, the thickness of the pressure-sensitive adhesive resin-containing pressure-sensitive adhesive layer whose surface is the pressure-sensitive adhesive surface is the same as that of the conventional or normal tackifying resin. The amount of the organic solvent remaining in the laminated pressure-sensitive adhesive layer or the pressure-sensitive adhesive resin-containing pressure-sensitive adhesive layer while ensuring an excellent level of adhesion and terminal peeling prevention by reducing the thickness of the pressure-sensitive adhesive layer. Can be reduced. In addition, the thickness of a polymer layer can be made into the thickness by which the tackifying resin containing adhesive layer was reduced rather than the conventional or normal tackifying resin containing adhesive layer.

  In the present invention, the pressure-sensitive adhesive sheet means a sheet-like pressure-sensitive adhesive material having or having a form of a sheet-like material having a pressure-sensitive adhesive layer. Specifically, the adhesive sheets include an adhesive tape, an adhesive sheet, an adhesive film, an adhesive label, and the like.

  In addition, as said adhesive sheet, if it has a lamination adhesive layer, it may have other layers (for example, intermediate | middle layer, undercoat layer etc.) in the range which does not impair the effect of this invention. .

  Such pressure-sensitive adhesive sheets can be manufactured according to a normal pressure-sensitive adhesive tape or pressure-sensitive adhesive sheet manufacturing method according to the type of pressure-sensitive adhesive sheets. Specifically, when the pressure-sensitive adhesive sheets are of a type with a base material, the type of pressure-sensitive adhesive sheet with a base material is, for example, (1) water-dispersed acrylic on at least one side (one side or both sides) of the base material. A polymer composition containing a polymer is applied so that the thickness after drying becomes a predetermined thickness and dried to form a polymer layer, and then a water-dispersed acrylic polymer is formed on the polymer layer. A water-dispersed acrylic pressure-sensitive adhesive containing an emulsion containing a tackifying resin is applied and dried so that the thickness after drying becomes a predetermined thickness, and a pressure-sensitive adhesive layer (tackifying resin-containing pressure-sensitive adhesive layer) (2) A polymer composition containing a water-dispersed acrylic polymer is applied onto a separator so that the thickness after drying is a predetermined thickness, and dried. After forming the polymer layer, the polymer layer A water-dispersed acrylic pressure-sensitive adhesive containing a water-dispersible acrylic polymer and an emulsion containing a tackifying resin is applied onto the polymer layer so that the thickness after drying becomes a predetermined thickness and dried. The pressure-sensitive adhesive layer (tackifying resin-containing pressure-sensitive adhesive layer) is formed to form a laminate of the polymer layer and the tackifying resin-containing pressure-sensitive adhesive layer, and then the laminate is applied to at least one surface of the substrate. (3) A method of producing by transferring in a form in which the surface of the substrate and the surface on the polymer layer side of the laminate are in contact with (one side or both sides), (3) at least one side of the substrate (single side or both sides) Next, a polymer composition containing a water-dispersed acrylic polymer is applied and dried so that the thickness after drying becomes a predetermined thickness, and a polymer layer is formed to laminate the substrate and the polymer layer. Form the body, and separately, on the separator, moisture A water-dispersed acrylic pressure-sensitive adhesive containing an acrylic polymer and an emulsion containing a tackifying resin is applied and dried so that the thickness after drying becomes a predetermined thickness, and a pressure-sensitive adhesive layer (adhesive And the surface of the pressure-sensitive adhesive resin-containing pressure-sensitive adhesive layer and the surface of the polymer layer are in contact with the laminate of the base material and the polymer layer. In such a form, it can be produced by a method of producing by transferring.

  On the other hand, when the pressure-sensitive adhesive sheet is a substrate-less type, the substrate-less type pressure-sensitive adhesive sheet is, for example, (1) at least one release surface of a release liner (a surface of a release treatment layer or a low-adhesive substrate). A polymer composition containing a water-dispersed acrylic polymer is applied on the surface, etc. so that the thickness after drying becomes a predetermined thickness, and dried to form a polymer layer. A water-dispersed acrylic pressure-sensitive adhesive containing a water-dispersible acrylic polymer and an emulsion containing a tackifying resin is applied and dried so that the thickness after drying becomes a predetermined thickness, followed by adhesion. It can produce by the method of producing by forming an agent layer (tackifying resin containing adhesive layer).

  In the pressure-sensitive adhesive sheets shown in FIGS. 1B, 1D, and 1F, the pressure-sensitive adhesive surface on one side of the pressure-sensitive adhesive sheet (the surface of the pressure-sensitive adhesive resin-containing pressure-sensitive adhesive layer) and the other side. To produce pressure-sensitive adhesive sheets wound in a roll shape by overlapping the release surface (the back treatment layer surface of the substrate, the release treatment layer surface of the release liner, etc.) and winding them into a roll shape. Can do.

  In addition, when forming a polymer layer or a tackifying resin-containing pressure-sensitive adhesive layer, when crosslinking is performed, the type of the crosslinking agent (for example, a thermal crosslinking type crosslinking agent that is crosslinked by heating, a photocrosslinking type that is crosslinked by ultraviolet irradiation) Depending on the crosslinking agent or the like, crosslinking can be carried out in a predetermined production process by a known or conventional crosslinking method. For example, when the crosslinking agent used is a thermal crosslinking type crosslinking agent, after applying the polymer composition and the water-dispersed acrylic pressure-sensitive adhesive, when drying, in parallel or simultaneously with this drying, Crosslinking can be performed by advancing the thermal crosslinking reaction. Specifically, depending on the type of thermal crosslinking type crosslinking agent, crosslinking can be performed together with drying by heating to a temperature equal to or higher than the temperature at which the crosslinking reaction proceeds.

  In the present invention, when the polymer composition or the water-dispersed acrylic pressure-sensitive adhesive is applied and then dried, it is preferable to enhance the drying as much as possible. Thus, when drying is strengthened, the organic solvent remaining in the pressure-sensitive adhesive sheet or the pressure-sensitive adhesive resin-containing pressure-sensitive adhesive layer can be further reduced, and the amount of organic solvent emitted is further reduced. Sheets can be obtained.

In such pressure-sensitive adhesive sheets, the residual amount of the organic solvent is preferably 10 μg / g or less after heating at 150 ° C. for 30 minutes, and more preferably 5 μg / g or less. is there. When the residual amount of the organic solvent in the pressure-sensitive adhesive sheet exceeds 10 μg / g, it is used for applications in a closed system space such as automotive materials such as automobile interior materials and residential materials such as housing building materials. There are concerns about the effects on the human body such as poor physical condition and health problems, which is not preferable. The remaining amount of the organic solvent in the pressure-sensitive adhesive sheets can be measured as follows.
First, a predetermined size (area: 5 cm ² ) is cut from the pressure-sensitive adhesive sheet to prepare a sample, and the sample is put in a vial and sealed. Thereafter, the vial containing the sample is heated at 150 ° C. for 30 minutes by a headspace autosampler, and 1.0 ml of the heated gas is injected into a gas chromatograph measuring device (GC measuring device) to determine the amount of toluene. Measure, calculate and quantify the toluene content (μg / g) per unit weight of the sample (adhesive sheets). The measurement conditions for the gas chromatograph are as follows.
(Gas chromatograph measurement conditions)
Column: DB-FFAP 1.0 μm (0.535 mmφ × 30 m)
Carrier gas: He 5.0 mL / min
-Column head pressure: 23 kPa (40 ° C.)
・ Inlet: Split (split ratio 12: 1, temperature 250 ° C.)
Column temperature: 40 ° C. (0 min) − <+ 10 ° C./min>−250 (9 min) [After raising the temperature from 40 ° C. to 250 ° C. at a rate of temperature increase of 10 ° C./min, hold at 250 ° C. for 9 minutes. means]
-Detector: FID (temperature: 250 ° C)

  Further, as the pressure-sensitive adhesive sheets, the reflectance by the fogging test according to German Industrial Standard DIN75201 (referred to as “fogging test reflectance”) from the viewpoint of suppressing or preventing the deterioration of the visibility of the glass such as the windshield of the automobile. In some cases) is preferably 70% or more, more preferably 80% or more (particularly 90% or more). Furthermore, from the same viewpoint as described above, the amount of adhesion by a fogging test according to German Industrial Standard DIN75201 (sometimes referred to as “fogging test adhesion amount”) is preferably 2.0 mg or less. 5 mg or less (particularly 1.0 mg or less) is preferred. In addition, when the fogging test reflectance of the adhesive sheet is less than 70% or the fogging test adhesion amount exceeds 2.0 mg, for example, when the adhesive sheet is used for an automobile interior material, When the temperature inside the vehicle becomes high, volatile components evaporate from the automobile interior material, and the windshield easily becomes cloudy, which may reduce visibility.

In the present invention, the fogging test reflectivity is measured according to German Industrial Standard DIN75201-R. Specifically, the pressure-sensitive adhesive sheets are cut into a circular shape with a diameter of 80 mm, and the pressure-sensitive adhesive layer surface (adhesive surface) is exposed by peeling the release liner or the like (both surfaces on which both surfaces are adhesive surfaces) In the pressure-sensitive adhesive sheets, with only one pressure-sensitive adhesive surface exposed, a beaker heated by an oil bath at 100 ° C. (outer diameter: 90 mm, inner diameter: 83.6 mm, height: 190 mm; height: 130 mm) A glass plate that is immersed in a 100 ° C. oil bath, with the exposed adhesive surface on the top, and that is constantly cooled to 21 ° C. on the top surface of the beaker. (Fogging measuring device: device name “N8-FOG” manufactured by HAAKE; a device capable of heating a beaker, a flask, etc. to 100 ° C. by an oil bath and cooling the upper surface to 21 ° C.). In that state, after leaving for 3 hours, the glass plate was taken out, and the reflectivity when incident light was incident on the surface of the glass plate inside the beaker at an incident angle of 60 ° (“60 ° of the glass plate after the test”). (Which may be referred to as “incidence reflectance”) (%) is determined using the trade name “REFO 60 REFLEKTOMETER” (manufactured by PRLANGE) [60 ° incidence reflectance (%) of glass plate after test = post-test Intensity of incident light on glass plate / intensity of reflected light when incident light is incident on glass plate after test × 100]. In addition, the reflectance when the incident light is incident at an incident angle of 60 ° (also referred to as “60 ° incident reflectance of the glass plate before the test” in advance) also on the surface of the glass plate before the test is performed. ) (%) Is determined using the same apparatus as above [60 ° incidence reflectance of glass plate before test (%) = intensity of incident light on glass plate before test / glass plate before test The intensity of reflected light when incident light is incident on x100]. Then, the fogging test reflectance (%) is calculated using the following formula (1).
Fogging test reflectance (%) = [60 ° incidence reflectance of glass plate after test (%) / 60 ° incidence reflectance of glass plate before test (%)] × 100 (1)

The fogging test adhesion amount is measured according to German Industrial Standard DIN75201-W. Specifically, the pressure-sensitive adhesive sheets are cut into a circular shape with a diameter of 80 mm, and the pressure-sensitive adhesive layer surface (adhesive surface) is exposed by peeling the release liner or the like (both surfaces on which both surfaces are adhesive surfaces) In the pressure-sensitive adhesive sheets, with only one pressure-sensitive adhesive surface exposed, a beaker heated by an oil bath at 100 ° C. (outer diameter: 90 mm, inner diameter: 83.6 mm, height: 190 mm; height: 130 mm) It is soaked in an oil bath at 100 ° C.) and is left standing with the exposed adhesive surface on the top, and the top surface of the beaker is always cooled to 21 ° C. A sheet (so-called “aluminum foil”) is installed (fogging measuring device: device name “N8-FOG” manufactured by HAAKE). In this state, after leaving for 16 hours, the aluminum sheet is taken out, and its weight (the weight of the aluminum sheet after the test) is measured. In addition, the weight of the aluminum sheet before the test (the weight of the aluminum sheet before the test) is also measured in advance. Then, the fogging test adhesion amount (mg) is calculated using the following formula (2).
Fogging test adhesion amount (mg) = (weight of aluminum sheet after test) − (weight of aluminum sheet before test) (2)

  When the polymer layer or the tackifying resin-containing pressure-sensitive adhesive layer is formed by crosslinking, the ratio of the solvent-insoluble matter (cross-linked acrylic polymer) in the polymer layer or the tackifying resin-containing pressure-sensitive adhesive layer is not particularly limited, The amount is preferably about 15 to 70% by weight based on the total solid content in the polymer layer or the tackifying resin-containing pressure-sensitive adhesive layer. In this case, the acrylic polymer of the solvent-soluble content in the polymer layer or the tackifying resin-containing pressure-sensitive adhesive layer has a weight average molecular weight (polystyrene conversion, analyzer: “HLC-8120GPC” manufactured by TOSOH, column: “ TSKgel GMH-H (S) ") is desirably 100,000 to 600,000 (preferably 200,000 to 450,000).

  In addition, the ratio of the crosslinked body of the acrylic polymer as the solvent-insoluble content after crosslinking and the molecular weight (weight average molecular weight) of the acrylic polymer as the solvent-soluble content are, for example, functional group-containing monomers with respect to the total amount of the monomer components. It can be arbitrarily set by appropriately adjusting the component ratio, the type and ratio of the chain transfer agent, the type and ratio of the crosslinking agent, and the like.

  The pressure-sensitive adhesive sheets of the present invention have high adhesiveness and excellent terminal peeling resistance, and the remaining amount of organic solvent is small, and further, the occurrence of fogging phenomenon is reduced. Even if it is used in a closed system space such as automobile materials such as materials and housing materials such as housing construction materials, the impact on the human body can be reduced. The occurrence of fogging fogging can be reduced. Therefore, the pressure-sensitive adhesive sheets of the present invention can be suitably used for fixing automobile materials or residential materials.

  Examples of the present invention will be described below in more detail. In the following, “parts” means “parts by weight”, and “%” means “% by weight”.

Example 1
Using a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, butyl acrylate: 90 parts, 2-ethylhexyl acrylate: 10 parts, acrylic acid: 4 parts, dodecanethiol (chain transfer agent): 0 .05 parts, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride (polymerization initiator): 0.1 part of sodium polyoxyethylene lauryl sulfate (emulsifier) ): In addition to 100 parts of water to which 1.5 parts were added, the reaction vessel was charged and heated to 60 ° C. while stirring, and subjected to an emulsion polymerization reaction at 60 ° C. for 4 hours, and then aged for 2 hours. As a result, a reaction mixture containing an acrylic polymer was obtained.

  To the reaction mixture, 10% aqueous ammonia was added to adjust the pH to 7, and subsequently, a water-soluble oxazoline-based crosslinking agent (oxazoline-type crosslinking agent) dissolved in water (trade name “Epocross WS-”). 500 ”(manufactured by Nippon Shokubai Chemical Co., Ltd.) was added to obtain an aqueous dispersion of an acrylic polymer (water-dispersed acrylic polymer).

  The water-dispersed acrylic polymer is applied to the surface of the release treatment layer of a release liner (trade name “SLB-80WD (V2)” manufactured by Kite Chemical Industries, Ltd.) having a release treatment layer with a silicone release agent. The polymer layer (first pressure-sensitive adhesive layer) having a thickness of 70 μm was formed by drying at 100 ° C. for 2 minutes.

  In addition, the water-dispersed acrylic polymer has a trade name “TAMANOL E-200” (Arakawa Chemical) as an emulsion containing a tackifying resin with respect to 100 parts (solid content) of the water-dispersed acrylic polymer. Kogyo Co., Ltd .; rosin phenol-based resin) was added in an amount of 30 parts in terms of solid content to obtain a water-dispersed pressure-sensitive adhesive (water-dispersed acrylic pressure-sensitive adhesive) containing a tackifying resin.

  This water-dispersed acrylic pressure-sensitive adhesive is applied onto the polymer layer and dried at 100 ° C. for 1 minute to form a 10 μm thick water-dispersed acrylic pressure-sensitive adhesive layer (second pressure-sensitive adhesive layer). Thus, an adhesive sheet was produced. That is, in this pressure-sensitive adhesive sheet, a water-dispersed acrylic pressure-sensitive adhesive layer (thickness: 10 μm) as a second pressure-sensitive adhesive layer was formed on a polymer layer (thickness: 70 μm) as a first pressure-sensitive adhesive layer. It is a substrate-less type pressure-sensitive adhesive sheet having a configuration, and the total thickness of the pressure-sensitive adhesive layer (the total thickness of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer) is 80 μm. In the pressure-sensitive adhesive sheet, the emulsion containing the tackifying resin is not contained in the first pressure-sensitive adhesive layer (polymer layer), and the thin second pressure-sensitive adhesive layer (water-dispersed acrylic pressure-sensitive adhesive) Layer) only included.

(Example 2)
In the same manner as in Example 1, two pressure-sensitive adhesive sheets were produced. After releasing the release liner from each adhesive sheet, each adhesive sheet is attached to both sides of a non-woven fabric substrate (trade name “SP base paper-14” manufactured by Daifuku Paper Co., Ltd.), and a polymer layer (first adhesive layer). Were bonded together in the form of being in contact with the surface of the non-woven fabric substrate to produce an adhesive sheet. That is, this pressure-sensitive adhesive sheet has a polymer layer (thickness: 70 μm) as a first pressure-sensitive adhesive layer and a water-dispersed acrylic pressure-sensitive adhesive layer (second pressure-sensitive adhesive layer) on one surface of a nonwoven fabric substrate. (Thickness: 10 μm) is formed in this order, and a polymer layer (thickness: 70 μm) as the first pressure-sensitive adhesive layer and water dispersion as the second pressure-sensitive adhesive layer are formed on the other surface of the nonwoven fabric substrate. Type double-sided pressure-sensitive adhesive sheet (second pressure-sensitive adhesive layer / first pressure-sensitive adhesive layer / non-woven fabric base) having a configuration in which a type acrylic pressure-sensitive adhesive layer (thickness: 10 μm) is formed in this order Material / first pressure-sensitive adhesive layer / second pressure-sensitive adhesive layer), and the total thickness of the pressure-sensitive adhesive layer on each surface of the nonwoven fabric substrate (first pressure-sensitive adhesive layer and second pressure-sensitive adhesive layer) The total thickness of the layer is 80 μm. In the pressure-sensitive adhesive sheet, an emulsion containing a tackifying resin (trade name “Tamanol E-200”) is not included in the first pressure-sensitive adhesive layer (polymer layer), and the second pressure-sensitive adhesive layer is a thin layer. It is contained only in the agent layer (water-dispersed acrylic pressure-sensitive adhesive layer).

(Example 3)
In the water-dispersed acrylic pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer in Example 1, the trade name “Tamanol E-200” (manufactured by Arakawa Chemical Industries, Ltd .; rosin phenol-based resin) as an emulsion containing a tackifier resin Instead of the trade name “Tamanol E-200-NT” (manufactured by Arakawa Chemical Industries, Ltd .; rosin phenolic resin) with the same ratio (namely, water-dispersed acrylic polymer: 100 parts (solid content)) Two adhesive sheets were produced in the same manner as in Example 1 except that the ratio was 30 parts in terms of solid content). Then, a double-sided pressure-sensitive adhesive sheet with a base material was produced in the same manner as in Example 2 except that two of the pressure-sensitive adhesive sheets were used. Specifically, after releasing the release liner from each pressure-sensitive adhesive sheet, each pressure-sensitive adhesive sheet is attached to both sides of a nonwoven fabric substrate (trade name “SP base paper-14” manufactured by Daifuku Paper Co., Ltd.) with a polymer layer (first 1 pressure-sensitive adhesive layer) was bonded to form a pressure-sensitive adhesive sheet in contact with the surface of the nonwoven fabric substrate. That is, this pressure-sensitive adhesive sheet has a polymer layer (thickness: 70 μm) as a first pressure-sensitive adhesive layer and a water-dispersed acrylic pressure-sensitive adhesive layer (second pressure-sensitive adhesive layer) on one surface of a nonwoven fabric substrate. (Thickness: 10 μm) is formed in this order, and a polymer layer (thickness: 70 μm) as the first pressure-sensitive adhesive layer and water dispersion as the second pressure-sensitive adhesive layer are formed on the other surface of the nonwoven fabric substrate. Type double-sided pressure-sensitive adhesive sheet (second pressure-sensitive adhesive layer / first pressure-sensitive adhesive layer / non-woven fabric base) having a configuration in which a type acrylic pressure-sensitive adhesive layer (thickness: 10 μm) is formed in this order Material / first pressure-sensitive adhesive layer / second pressure-sensitive adhesive layer), and the total thickness of the pressure-sensitive adhesive layer on each surface of the nonwoven fabric substrate (first pressure-sensitive adhesive layer and second pressure-sensitive adhesive layer) The total thickness of the layer is 80 μm. In the pressure-sensitive adhesive sheet, an emulsion containing a tackifying resin (trade name “Tamanol E-200-NT”) is not included in the first pressure-sensitive adhesive layer (polymer layer), and the thin layer first It is contained only in 2 pressure-sensitive adhesive layers (water-dispersed acrylic pressure-sensitive adhesive layer).

(Comparative Example 1)
In the same manner as in Example 1, an aqueous dispersion of an acrylic polymer (water-dispersed acrylic polymer) was obtained. That is, using a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer, butyl acrylate: 90 parts, 2-ethylhexyl acrylate: 10 parts, acrylic acid: 4 parts, dodecanethiol (chain transfer agent) : 0.05 part, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride (polymerization initiator): 0.1 part of sodium polyoxyethylene lauryl sulfate (Emulsifier): In addition to 100 parts of water to which 1.5 parts have been added, the reaction vessel is charged with stirring, heated to 60 ° C., and subjected to an emulsion polymerization reaction at 60 ° C. for 4 hours. After aging for a time to obtain a reaction mixture containing an acrylic polymer, 10% ammonia water was added to the reaction mixture to adjust the pH to 7, followed by water-solubility dissolved in water. No 0.7 parts of a sazoline-based cross-linking agent (oxazoline-type cross-linking agent) (trade name “Epocross WS-500” manufactured by Nippon Shokubai Chemical Industry Co., Ltd.) is added, and an aqueous dispersion of an acrylic polymer (water-dispersed acrylic type) Polymer).

  This water-dispersed acrylic polymer was applied to the surface of the release treatment layer of a release liner (trade name “SLB-80WD (V2)” manufactured by Kite Chemical Industries, Ltd.) having a release treatment layer with a silicone release agent. It dried at 100 degreeC for 1 minute, the 80 micrometer-thick water dispersion type acrylic polymer layer was formed, and the adhesive sheet was produced. That is, this pressure-sensitive adhesive sheet is a substrate-less type pressure-sensitive adhesive sheet having a configuration in which only a water-dispersed acrylic polymer layer (thickness: 80 μm) is formed as a pressure-sensitive adhesive layer. Therefore, the pressure-sensitive adhesive sheet does not contain an emulsion containing a tackifying resin.

(Comparative Example 2)
In the same manner as in Example 1, a water-dispersed pressure-sensitive adhesive (water-dispersed acrylic pressure-sensitive adhesive) containing a tackifying resin was obtained. That is, using a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer and a stirrer, butyl acrylate: 90 parts, 2-ethylhexyl acrylate: 10 parts, acrylic acid: 4 parts, dodecanethiol (chain transfer agent) : 0.05 part, 2,2′-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride (polymerization initiator): 0.1 part of sodium polyoxyethylene lauryl sulfate (Emulsifier): In addition to 100 parts of water to which 1.5 parts have been added, the reaction vessel is charged with stirring, heated to 60 ° C., and subjected to an emulsion polymerization reaction at 60 ° C. for 4 hours. After aging for a time to obtain a reaction mixture containing an acrylic polymer, 10% ammonia water was added to the reaction mixture to adjust the pH to 7, followed by water-solubility dissolved in water. No 0.7 parts of a sazoline-based cross-linking agent (oxazoline-type cross-linking agent) (trade name “Epocross WS-500” manufactured by Nippon Shokubai Chemical Industry Co., Ltd.) is added, and an aqueous dispersion of an acrylic polymer (water-dispersed acrylic type) In addition, the water-dispersed acrylic polymer was added to the water-dispersed acrylic polymer: 100 parts (solid content) as an emulsion containing a tackifying resin. E-200 "(manufactured by Arakawa Chemical Industries, Ltd .; rosin phenol-based resin) is added in an amount of 30 parts in terms of solid content, and a water-dispersed pressure-sensitive adhesive (water-dispersed acrylic pressure-sensitive adhesive) containing a tackifying resin is added. Obtained.

  This water-dispersed acrylic pressure-sensitive adhesive was applied to the surface of a release treatment layer of a release liner (trade name “SLB-80WD (V2)” manufactured by Kite Chemical Industries, Ltd.) having a release treatment layer with a silicone release agent. It dried at 100 degreeC for 1 minute, the 80 micrometer-thick water dispersion type acrylic adhesive layer was formed, and the adhesive sheet was produced. That is, this pressure-sensitive adhesive sheet is a substrate-less type pressure-sensitive adhesive sheet having a configuration in which only a water-dispersed acrylic pressure-sensitive adhesive layer (thickness: 80 μm) is formed as a pressure-sensitive adhesive layer. Moreover, it has the structure by which the emulsion containing tackifying resin was contained in the water dispersion type acrylic adhesive layer. Therefore, in the said adhesive sheet, the emulsion containing tackifying resin is contained in the whole adhesive layer.

(Evaluation)
About each adhesive sheet obtained in Examples and Comparative Examples, the remaining amount of organic solvent, the fogging test reflectance (reflectance according to the fogging test according to German Industrial Standard DIN75201), the fogging test adhesion amount (according to German Industrial Standard DIN75201) The amount of adhesion by the fogging test), terminal peeling prevention property, and adhesive strength were measured or evaluated by the following methods. The results are shown in Table 1.

(Measurement method of remaining amount of organic solvent)
A predetermined size (area: 5 cm ² ) was cut from each adhesive sheet to prepare a sample, and the sample was put in a vial and sealed. Thereafter, the bottle containing the sample is heated at 150 ° C. for 30 minutes by a headspace autosampler, and 1.0 ml of the heated gas is injected into the gas chromatograph measuring apparatus, and the remaining amount of organic solvent (μg / g) Was measured.

(Fogging test reflectivity measurement method)
The fogging test reflectivity is carried out according to German industry standard DIN 75201-R. Specifically, each pressure-sensitive adhesive sheet is cut into a circular shape with a diameter of 80 mm, and only a release liner (release paper) on one side is peeled off, and a beaker heated by an oil bath at 100 ° C. (outside The inner surface of the inner diameter of 90 mm, the inner diameter of 83.6 mm, and the height: 190 mm; immersed in a 100 ° C. oil bath up to a height of 130 mm) has an adhesive surface exposed by peeling of the release liner on the upper side. Furthermore, the glass plate which is always cooled at 21 degreeC is installed in the upper surface of a beaker (fogging measuring device: apparatus name "N8-FOG" HAAKE Corporation make). In that state, after leaving for 3 hours, the glass plate was taken out, and the reflectivity when incident light was incident on the surface of the glass plate inside the beaker at an incident angle of 60 ° (“60 ° of the glass plate after the test”). (Which may be referred to as “incidence reflectance”) (%) is determined using the trade name “REFO 60 REFLEKTOMETER” (manufactured by PRLANGE) [60 ° incidence reflectance (%) of glass plate after test = post-test Intensity of incident light on glass plate / intensity of reflected light when incident light is incident on glass plate after test × 100]. In addition, the reflectance when the incident light is incident at an incident angle of 60 ° (also referred to as “60 ° incident reflectance of the glass plate before the test” in advance) also on the surface of the glass plate before the test is performed. ) (%) Is determined using the same apparatus as above [60 ° incidence reflectance of glass plate before test (%) = intensity of incident light on glass plate before test / glass plate before test The intensity of reflected light when incident light is incident on x100]. Then, the fogging test reflectance (%) is calculated using the following formula (1).
Fogging test reflectance (%) = [60 ° incidence reflectance of glass plate after test (%) / 60 ° incidence reflectance of glass plate before test (%)] × 100 (1)

(Measurement method of fogging test adhesion amount)
The fogging test adhesion amount is carried out in accordance with German Industrial Standard DIN 75201-W. Specifically, each pressure-sensitive adhesive sheet is cut into a circular shape with a diameter of 80 mm, and only a release liner (release paper) on one side is peeled off, and a beaker heated by an oil bath at 100 ° C. (outside The inner surface of the inner diameter of 90 mm, the inner diameter of 83.6 mm, and the height: 190 mm; immersed in a 100 ° C. oil bath up to a height of 130 mm) has an adhesive surface exposed by peeling of the release liner on the upper side. In addition, an aluminum sheet (so-called “aluminum foil”) that is always cooled to 21 ° C. is installed on the upper surface of the beaker (fogging measuring device: device name “N8-FOG”, manufactured by HAAKE) ). In this state, after leaving for 16 hours, the aluminum sheet is taken out, and its weight (the weight of the aluminum sheet after the test) is measured. In addition, the weight of the aluminum sheet before the test (the weight of the aluminum sheet before the test) is also measured in advance. Then, the fogging test adhesion amount (mg) is calculated using the following formula (2).
Fogging test adhesion amount (mg) = (weight of aluminum sheet after test) − (weight of aluminum sheet before test) (2)

(Evaluation method of device peeling prevention)
Each adhesive sheet is attached to an aluminum plate (area: 10 mm × 100 mm) having a thickness of 0.5 mm so that the surface of the water-dispersed acrylic adhesive layer is in contact with the aluminum plate, and then the other adhesive. Surface (the pressure-sensitive adhesive sheet according to Example 1 is the surface of the polymer layer, the pressure-sensitive adhesive sheet according to Example 2 is the surface of the water-dispersed acrylic pressure-sensitive adhesive layer on the other surface side, and the pressure-sensitive adhesive sheet according to Comparative Example 1 is the water-dispersed type The other surface of the acrylic pressure-sensitive adhesive layer, the pressure-sensitive adhesive sheet according to Comparative Example 2 is the surface of the water-dispersed acrylic pressure-sensitive adhesive layer on the other surface side), and the side surface of a cylindrical acrylic round bar having a diameter of 50 mm. Pasted together. This was left for 2 hours in an atmosphere at 70 ° C. with the round bar upright, and the distance (height) (mm) at which the end of the aluminum plate was peeled was measured.

(Measurement method of adhesive strength)
Each pressure-sensitive adhesive sheet was pressure-bonded to a stainless steel (SUS) plate by reciprocating a 2 kg roller once, left at 23 ° C. for 20 minutes, and then pulled using a tensile tester at a tensile speed of 300 mm / min. The peel adhesive strength (23 ° C., 50% RH; N / 20 mm) was measured.

  From Table 1, the adhesive sheets according to Examples 1 and 2 have reduced residual amount of organic solvent while maintaining good terminal peeling prevention and adhesive strength, and further, fogging test reflectivity and fogging test adhesion It was confirmed that an adhesive sheet having a good amount and having a high safety can be obtained.

Fig.1 (a)-(f) is a schematic sectional drawing which respectively shows the example of the adhesive sheets of this invention.

Explanation of symbols

11 to 16, respectively, adhesive sheets 2 base material 3 polymer layer 4 tackifying resin-containing adhesive layer 5 release liner

Claims (10)

A pressure-sensitive adhesive sheet having a configuration in which a pressure-sensitive adhesive layer is formed on at least one surface of a support, and a polymer layer made of a polymer composition containing a water-dispersible acrylic polymer on at least one surface of the support A pressure-sensitive adhesive layer made of a water-dispersible acrylic pressure-sensitive adhesive containing a water-dispersible acrylic polymer and an emulsion containing a tackifying resin has a structure formed in this order ,
The monomer component constituting the acrylic polymer in the water-dispersed acrylic polymer is mainly composed of (meth) acrylic acid alkyl ester, and the (meth) acrylic acid alkyl ester is represented by the following formula (1). In the following formula (1), R ² is an alkyl group having 2 to 14 carbon atoms,
The emulsion containing the tackifying resin is an emulsion containing a tackifying resin prepared by dissolving the tackifying resin in an organic solvent and then emulsifying the emulsion.
A pressure-sensitive adhesive sheet characterized by having a reflectance of 70% or more according to a fogging test according to German Industrial Standard DIN75201 .

(In Formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group.) The pressure-sensitive adhesive sheet according to claim 1, wherein the ratio of the alkyl (meth) acrylate to the total amount of monomer components constituting the acrylic polymer is 80% by weight or more. The (meth) acrylic acid alkyl ester is butyl acrylate alone or a combination of butyl acrylate and 2-ethylhexyl acrylate, and the ratio of butyl acrylate to 2-ethylhexyl acrylate is 2-ethylhexyl acrylate / The pressure-sensitive adhesive sheets according to claim 1 or 2, wherein butyl acrylate (weight ratio) = 0/100 to 55/45. The pressure-sensitive adhesive sheet according to any one of claims 1 to 3 , wherein the pressure-sensitive adhesive layer has a thickness of 2 to 50 µm. The tackifier resin is at least one tackifier resin selected from the group consisting of a rosin ester resin, a terpene tackifier resin, a hydrocarbon tackifier resin, and a phenol tackifier resin. The pressure-sensitive adhesive sheet according to any one of the above. The pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the organic solvent is an alicyclic hydrocarbon-based organic solvent. The pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the residual amount of the organic solvent is 10 µg / g or less after heating at 150 ° C for 30 minutes. The pressure-sensitive adhesive sheet according to any one of claims 1 to 7, which has a structure in which a tackifying resin-containing pressure-sensitive adhesive layer is formed on both surfaces of a base material as a support via a polymer layer. The tackifying resin-containing pressure-sensitive adhesive layer on either side has a configuration protected by a release liner whose both surfaces are release surfaces, and the other side of the tackifying resin-containing pressure-sensitive adhesive layer is The pressure-sensitive adhesive sheet according to claim 8, wherein the pressure-sensitive adhesive sheet is configured to be protected by the other release surface of the release liner by winding the pressure-sensitive adhesive sheet in a roll shape. The pressure-sensitive adhesive sheet according to any one of claims 1 to 9, which is used for fixing an automobile material or a housing material.

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