JP2020023597A - Tackifier resin aqueous dispersion, aqueous adhesive and adhesive sheet - Google Patents

Abstract

To provide a tackifier resin aqueous dispersion that has an extremely small content of an organic solvent, and gives excellent storage stability, mechanical stability, coatability, workability, adhesiveness, curved surface adhesiveness, moist heat resistance, constant load peelability, and base material adhesion.SOLUTION: A tackifier resin aqueous dispersion has, based on a tackifier resin (A) with a softening point of 100-180°C, and a copolymer resin (B) having an alicyclic structure and an ethylene oxide unit. Based on the tackifier resin (A) 100 pts.mass, the copolymer resin (B) content is 0.5-50 pts.mass. The organic solvent content is 1000 ppm or less.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous dispersion of a tackifying resin, and an aqueous pressure-sensitive adhesive and a pressure-sensitive adhesive sheet using the same.

  BACKGROUND ART Adhesives are widely used from industrial fields such as packaging, construction, building materials, automobiles, and electronic components to ordinary households. The most common laminated structure of the pressure-sensitive adhesive sheet is “base sheet / pressure-sensitive adhesive layer / peel sheet” (single-sided pressure-sensitive sheet) or “peel sheet / pressure-sensitive adhesive layer / base sheet / pressure-sensitive adhesive layer / peel sheet”. (Double-sided adhesive sheet). At the time of use, the release sheet is peeled off, and the pressure-sensitive adhesive layer is attached to the adherend. The pressure-sensitive adhesive sheet is used for various uses, and the required adhesive strength is also various.

  In recent years, from the viewpoint of protecting the global environment (suppressing the emission of volatile organic compounds), improving the working environment, and effectively using resources, water-based emulsion-based adhesives (hereinafter referred to as "water-based adhesives") have been used as alternatives to solvent-based adhesives. (Abbreviated as) has been studied. However, the water-based pressure-sensitive adhesive has a drawback that, as compared with the solvent-based pressure-sensitive adhesive, the adhesiveness to a substrate sheet and the adhesive force to a polyolefin-based adherend such as polyethylene and polypropylene are extremely poor. It has also been required to have a sufficient adhesive strength to hardly adherents such as adherends.

  In addition, in automotive applications and building material applications, there is a concern about sick car problems and sick house problems, and aqueous adhesives are widely used. In automotive applications, for example, in the case of interior parts, the temperature inside the vehicle becomes extremely high in summer, while in building materials, the temperature increases in an environment exposed to direct sunlight in summer. The agent is required to have heat resistance at such a high temperature, wet heat resistance, and heat resistance holding power.

  In recent years, substrate sheets have also been diversified. In particular, in automotive applications, sheet-like foams having irregularities on the surface, such as urethane foam, are porous, and therefore have a substantial contact area with the pressure-sensitive adhesive layer. Therefore, it was difficult to ensure the adhesion of the pressure-sensitive adhesive layer to the sheet-like foam. The sheet-like foam is thicker than a general base sheet such as a plastic film or paper, and has a large force to return to a flat state against bending, that is, a large restoring force. However, an adhesive sheet using a sheet-like foam as a base sheet is often attached to an adherend having an uneven surface or a curved surface as described above. Therefore, if the adhesiveness of the pressure-sensitive adhesive layer to the sheet-like foam is insufficient, the sheet-like foam cannot be stuck to the adherend against the restoring force of the sheet-like foam. That is, peeling occurs between the sheet-like foam and the pressure-sensitive adhesive layer, and the sheet-like foam peels from the adherend in a state where the pressure-sensitive adhesive layer remains on the adherend.

  On the other hand, even if the adhesiveness of the pressure-sensitive adhesive layer to the sheet-shaped foam is sufficient, if the adhesive force of the pressure-sensitive adhesive layer to the adherend is insufficient, the pressure between the adherend and the pressure-sensitive adhesive layer is reduced. Peeling occurs, and the sheet-like foam becomes integral with the pressure-sensitive adhesive layer and peels off from the adherend.

  As the aqueous pressure-sensitive adhesive, an acrylic polymer resin dispersion, a styrene-butadiene copolymer latex, a natural rubber latex, a chloroprene latex, and the like as a base polymer for improving heat resistance and adhesive strength, and a rosin-based resin, It is known that it is used as an aqueous adhesive obtained by mixing an aqueous dispersion of a tackifier resin such as a petroleum resin, a terpene resin, a phenol resin, a ketone resin, or a polyolefin resin. Usually, in such a tackifier resin aqueous dispersion, an aqueous dispersion of a rosin-based resin, a terpene-based resin, and a petroleum-based resin is widely used because of good compatibility with a base polymer and good adhesive properties. ing.

  Various attempts have been made to improve these problems. For example, a specific oxyalkylene group-containing monomer (a) and an ethylenically unsaturated monomer (b) having an anion group or an anion-forming group can be used. ) And an acrylic copolymer essentially comprising a copolymerizable hydrophobic monomer (c) as a polymer emulsifier, containing an aqueous resin dispersion of a rosin substance as an active ingredient and an aqueous resin dispersion of the resin. An aqueous sizing agent for papermaking is disclosed (see Patent Document 1). A homogeneous aqueous resin dispersion of a rosin substance can be obtained by using this polymer emulsifier, but when used as an aqueous adhesive by mixing with an aqueous acrylic resin, the storage stability over a long period of time. In addition, when a pressure-sensitive adhesive sheet is prepared, it can have low-temperature adhesiveness because of its high flexibility, but not only has extremely poor heat resistance and wet heat resistance, but also has poor adhesion to polyolefin-based adherends. Was enough.

  For example, a polymer having a glass transition temperature (Tg) of -80 ° C to 0 ° C other than the tackifier resin (A) having a nonvolatile content concentration of 65 to 99% by mass excluding the surfactant component and the tackifier resin (A) ( B) 1 to 35% by mass (provided that the total of the tackifying resin (A) and the polymer (B) is 100% by mass), and the organic solvent contained in the aqueous dispersion of the tackifying resin (A) An aqueous tackifier resin dispersion having an amount of 50 ppm or less is disclosed (see Patent Document 2). Since no organic solvent is used during the production of the tackifier resin aqueous dispersion, there is an advantage that no solvent is contained in the tackifier resin aqueous dispersion, but the tackifier resin aqueous dispersion is generally mixed with the acrylic resin. Since the pressure-sensitive adhesive sheet made from the water-based pressure-sensitive adhesive is low in glass transition temperature (Tg), heat resistance and heat-resistant holding power are extremely reduced.

  For example, the non-volatile matter concentration excluding the emulsifier component has a softening point of 135 to 180 ° C, an acid value of 20 to 65% by mass of the polymerized rosin ester resin (A) and an acid value other than (A) of 50 to 100, Acryl oligomer having a carboxyl group having a weight average molecular weight of 1,000 to 5,000 (B) is composed of 1 to 35% by mass [the total of components (A) and (B) is 100% by mass]. An aqueous dispersion of a tackifying resin containing 50 ppm or less of an organic solvent is disclosed (see Patent Document 3). Approximately an aqueous dispersion of tackifying resin is applied to minimize the content of organic solvent, so it is effective for environmental protection.However, an aqueous dispersion of a polymerized rosin ester resin is mixed with an acrylic resin to form an aqueous dispersion. As a pressure-sensitive adhesive, a pressure-sensitive adhesive sheet prepared from a substantially water-based pressure-sensitive adhesive has insufficient adhesion to a polyolefin-based adherend, and when an attempt is made to produce a resin-based aqueous dispersion containing no solvent, an aqueous dispersion In some cases, there were problems such as high viscosity and difficulty in handling.

  For example, a tackifier resin having a softening point of 120 to 190 ° C. dispersed in water under solvent-free and pressurized conditions in the presence of an acrylic oligomer having a mass average molecular weight of 500 to 50,000. An aqueous dispersion is disclosed (see Patent Document 4). Approximately the tackifier resin aqueous dispersion does not contain an organic solvent, so it is effective for environmental protection, etc.However, since a low molecular weight acrylic oligomer is used, unreacted acrylic monomer remains, so odor is generated. It tends to remain, and when the aqueous tackifier resin dispersion is mixed with an acrylic resin to form an aqueous pressure-sensitive adhesive, the storage stability decreases over a long period of time. Although it can have both adhesiveness and heat resistance, not only water resistance and wet heat resistance are remarkably inferior, but also adhesive strength to a polyolefin-based adherend is insufficient.

  Thus, when mixed with a base polymer to form an aqueous pressure-sensitive adhesive, it provides superior adhesive strength, heat resistance, wet heat resistance, and cohesion as compared with conventional pressure-sensitive adhesives, and uses an organic solvent. Thus, an aqueous dispersion of a tackifier resin having good storage stability has been desired.

JP-A-8-52340 JP 2007-002212 A JP 2008-195888 A JP 2005-330436 A

  From the viewpoint of contributing to environmental protection and occupational health, the present invention has a very low organic solvent content, excellent storage stability, mechanical stability, coating properties, processability, adhesion, curved surface adhesion, moisture and heat resistance, An object of the present invention is to provide an aqueous dispersion of a tackifying resin that gives constant load peelability and substrate adhesion, and an aqueous pressure-sensitive adhesive containing an aqueous dispersion of a general tackifying resin, and a pressure-sensitive adhesive sheet using the same. And

  The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the above-mentioned object can be achieved by the following tackifier resin aqueous dispersion, and have completed the present invention.

  That is, an embodiment of the present invention includes a tackifying resin (A) having a softening point of 100 to 180 ° C. and a copolymer resin (B) having an alicyclic structure and an ethylene oxide unit, A) A tackifier resin aqueous dispersion containing 0.5 to 50 parts by mass of the copolymer resin (B) with respect to 100 parts by mass and having an organic solvent content of 1000 ppm or less.

  In addition, an embodiment of the present invention provides an ethylenically unsaturated compound (b1) unit having an alicyclic structure and an ethylenically unsaturated compound having an ethylene oxide unit as monomer units constituting the copolymer resin (B). It contains a compound (b2) unit and an ethylenically unsaturated compound (b3) unit containing a carboxyl group, and 100 parts by mass of the copolymer resin (B), 10 to 30 parts by mass of the compound (b1), The above-mentioned tackifier resin aqueous dispersion comprising 55 to 80 parts by mass of the compound (b2) and 5 to 20 parts by mass of the compound (b3).

  Further, an embodiment of the present invention is the above tackifier resin aqueous dispersion, wherein the copolymer resin (B) has a mass average molecular weight of 1,000 to 300,000.

  Further, an embodiment of the present invention is the aqueous tackifier resin dispersion described above, wherein the copolymer resin (B) has a glass transition temperature within a range of -50 to 20 ° C.

  In an embodiment of the present invention, the tackifying resin (A) is at least one resin selected from the group consisting of a rosin resin, a terpene resin and a petroleum resin. It is a resin aqueous dispersion.

  Further, the embodiment of the present invention further comprises a liquid resin (C) having a mass average molecular weight of 300 to 50,000 (provided that the tackifying resin (A) and the copolymer resin (B) are used). The above-mentioned aqueous dispersion of tackifying resin is characterized in that:

  Further, an embodiment of the present invention is the above aqueous tackifier resin dispersion, further comprising a surfactant (D).

  Further, an embodiment of the present invention is the aqueous tackifier resin dispersion in which the surfactant (D) contains at least one of an anionic surfactant and a nonionic surfactant.

  An embodiment of the present invention is the above-mentioned aqueous dispersion of tackifier resin, further comprising a basic compound (E).

  Further, an embodiment of the present invention is the above tackifier resin aqueous dispersion, wherein the basic compound (E) is a tertiary amine.

  An embodiment of the present invention is an aqueous pressure-sensitive adhesive comprising the base polymer (P) and the above-mentioned aqueous dispersion of tackifier resin.

  An embodiment of the present invention is a pressure-sensitive adhesive sheet provided with a pressure-sensitive adhesive layer formed from the above-mentioned aqueous pressure-sensitive adhesive on a substrate (G).

  The present invention has an extremely low organic solvent content, excellent storage stability, mechanical stability, coatability, workability, adhesion, curved surface adhesion, wet heat resistance, constant load peelability, substrate adhesion. Aqueous tackifier resin aqueous dispersion and water-based pressure-sensitive adhesive which can provide a good water-based pressure-sensitive adhesive, and the provision of a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from the water-based pressure-sensitive adhesive, filterability, pot stain, It has become possible to provide a tackifying resin aqueous dispersion having a high softening point and excellent mechanical stability and storage stability.

Hereinafter, embodiments of the present invention will be described.
In this specification,
Tackifying resin (A) having a softening point of 100 to 180 ° C., copolymer resin (B) having an alicyclic structure and an ethylene oxide unit, ethylenically unsaturated compound (b1) having an alicyclic structure, ethylene oxide unit An ethylenically unsaturated compound (b2) having a carboxylic acid group, an ethylenically unsaturated compound having a carboxyl group (b3), and another ethylenically unsaturated compound (b4) are respectively converted into a tackifier resin (A) and a copolymer resin ( B), compound (b1), compound (b2), compound (b3), and compound (b4).

In addition, when described as “(meth) acryl”, “(meth) acryloyl”, “(meth) acrylic acid”, “(meth) acrylate”, “(meth) acryloyloxy”, and “(meth) allyl” Unless otherwise specified, respectively, `` acryl or methacryl '', `` acryloyl or methacryloyl '', `` acrylic or methacrylic acid '', `` acrylate or methacrylate '', `` acryloyloxy or methacryloyloxy '', and `` allyl or methacrylyl '' ].
Hereinafter, each component constituting the tackifier resin aqueous dispersion will be specifically described.

<Tackifying resin (A) having a softening point of 100 to 180 ° C>
Examples of the tackifying resin (A) having a softening point of 100 to 180 ° C include rosin-based resins, terpene-based resins, phenol-based resins, ketone-based resins, and petroleum-based resins.
Specific examples of rosin-based resins include modified rosins obtained by modifying rosins, hydrogenated rosins obtained by hydrogenating rosins, disproportionated rosins obtained by disproportionating rosins, rosin In addition to polymerized rosins obtained by polymerizing the compounds (these are collectively referred to as “raw material rosins”), rosin esters which are esterified products of these raw material rosins and alcohols, and the like are included. Examples of the modified rosins include unsaturated acid-modified rosins obtained by modifying rosins with unsaturated acids, and phenol-modified rosins obtained by modifying rosins with phenols. As the unsaturated acid used in the production of the unsaturated acid-modified rosins, for example, (meth) acrylic acid, fumaric acid, maleic acid and the like can be used. As phenols used for the phenol-modified rosins, for example, phenol, alkylphenol, and the like can be used. The modification method is not particularly limited, and a known method may be employed. Usually, a method of mixing a rosin with an unsaturated acid or a phenol and heating the mixture is employed.

  Specific examples of terpene-based resins include terpene-based resins obtained by polymerizing known terpenes such as α-pinene, β-pinene, and dipentene, or terpene phenols obtained by copolymerizing terpenes and phenols Resins and terpene phenol resins obtained by increasing the molecular weight can also be used. These terpene-based resins may be hydrogenated.

  As a specific example of the phenolic resin, a phenol-formaldehyde resin that is a condensate of phenols and formaldehyde can be used. Examples of the phenols include phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin, and the like.Resole obtained by addition reaction of these phenols and formaldehyde with an alkali catalyst or condensation reaction with an acid catalyst is used. And the like can be exemplified. Further, a phenol-acetylene resin obtained by a Reppe reaction using phenols and acetylene as a catalyst and zinc naphthenate or cadmium naphthenate as a catalyst can also be exemplified.

  Examples of the ketone resin include methyl ethyl ketone, methyl isobutyl ketone, acetophenone, cyclohexanone, and / or a condensate of methylcyclohexanone with formaldehyde.

  Examples of the petroleum-based resin include, among cracked oils other than olefins having 2 to 4 carbon atoms such as ethylene, propylene and butadiene in naphtha cracking, carbons obtained from pentene, pentadiene, isoprene, cyclopentadiene, dicyclopentadiene and the like. Aliphatic, alicyclic and aromatic compounds such as C5 petroleum resins obtained from C5 petroleum resins of several or more and indene, methylindene, vinyltoluene, styrene, α-methylstyrene, β-methylstyrene, etc. And resins obtained by polymerizing residual olefins of the above. Other examples include C5-C9 copolymer petroleum resins obtained from the above various monomers, coumarone-based resins composed of polymers of coumarone and indene which are fractions of coal tar, resins such as dammers and copals.

Among these tackifying resins, the tackifying resin used in the present invention has a softening point in the range of 100 to 180 ° C, more preferably in the range of 120 to 170 ° C, and particularly preferably in the range of 140 to 170 ° C. When the softening point is less than 100 ° C., not only is the adhesive strength not improved when contained in the pressure-sensitive adhesive, but also the heat-resistant holding power is unfavorably reduced, and when the softening point exceeds 180 ° C., the pressure-sensitive adhesive is Not only deteriorates the compatibility with the base polymer and the like, but also decreases the tackiness (also referred to as "tack") and the curved surface adhesion.
In addition, the softening point in the present invention is a temperature at which a substance softens due to a rise in temperature and starts to deform, and is a value measured by a ring and ball method (JIS K5902).
Among these tackifying resins, known resins can be used without any particular limitation as long as the softening point is in the range of 100 to 180 ° C., but rosin is used because of the compatibility of the base polymer and the development of good adhesion. A resin, a terpene resin, or a petroleum resin is preferable, and among them, a rosin resin is particularly preferable in terms of curved surface adhesion, water resistance, and heat and humidity resistance.

<Copolymer resin (B) having an alicyclic structure and an ethylene oxide unit>
The copolymer resin (B) having an alicyclic structure and an ethylene oxide unit has, as monomers constituting the copolymer, an ethylenically unsaturated compound (b1) unit having an alicyclic structure and an ethylene oxide unit The resin is preferably a resin containing an ethylenically unsaturated compound (b2) unit and a carboxyl group-containing ethylenically unsaturated compound (b3) unit, and is preferably a resin obtained by polymerizing a mixture of these monomers.

<<< ethylenically unsaturated compound having an alicyclic structure (b1) >>>
Compound (a1) is a compound having an alicyclic structure and an ethylenically unsaturated double bond group, and is a compound containing one or more residues having an alicyclic structure. The alicyclic structure is a saturated or unsaturated aliphatic hydrocarbon ring, and may have an aliphatic branch.
As the main alicyclic structure, for example, monocyclic cycloalkanes such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, cyclododecane;
For example, monocyclic cycloalkenes such as cyclopropene, cyclobutene, cyclopropene, cyclohexene, cycloheptene and cyclooctene.
For example, bicyclic alkanes such as spiropentane, spirodecane, bicycloundecane, decahydronaphthalene (decalin), norcanane, norbornane;
For example, bicyclic alkenes such as norbornene, norbornadiene and spiropentadiene;
For example, polycyclic structures such as dicyclopentadiene, adamantane, cubane, basket and hausan are exemplified.

The copolymer resin (B) using the ethylenically unsaturated compound (b1) having such an alicyclic structure as a monomer can not only improve a suitable cohesive force but also improve water resistance. And the heat and humidity resistance can be improved.
As the compound (b1), for example, cyclopentyl (meth) acrylate, 1-methyl-1-cyclopentyl (meth) acrylate, 1-ethyl-1-cyclopentyl (meth) acrylate, 1-isopropyl (meth) acrylate -1-cyclopentyl, cyclohexyl (meth) acrylate, 1-methyl-1-cyclohexyl (meth) acrylate, 1-ethyl-1-cyclohexyl (meth) acrylate, 4- (tert-butyl) (meth) acrylate Cyclohexyl, 1,3,5-trimethylcyclohexyl (meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, 1-isopropyl-1-cyclohexyl (meth) acrylate, cyclohexylmethyl (meth) acrylate , 1,4-cyclohexanedimer (meth) acrylate Nol, 2- (meth) acryloyloxyethyl hexahydrophthalate 1-ethyl-1-cyclooctyl (meth) acrylate, isobonyl (meth) acrylate, dicyclopentanyl (meth) acrylate, di (meth) acrylate Cyclopentanyloxyethyl, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, decahydronaphthalen-2-yl (meth) acrylate, decahydro-1,4- (meth) acrylate Methanonaphthalen-2-yl, decahydro-1,4,5,8-dimethanonaphthalen-2-yl (meth) acrylate, 2-ethyldecahydro-1,4: 5,8-di (meth) acrylate Methanoaphthalen-2-yl, decahydro-3,8: 4,7-dimethanocyclobutamate (meth) acrylate b] naphthalen-5-yl, dodecahydro-1H-4,9: 5,8-dimethanocyclopenta [b] naphthalen-5-yl (meth) acrylate, tetradecanohydro-1, (meth) acrylate, 4-methanoanthracen-2-yl, tetradecahydro-1,4: 9,10-dimethanoanthracen-2-yl (meth) acrylate, tetradecahydro-1,4: 5,8 (meth) acrylate , 9,10-Trimethanoanthracen-2-yl, (1s, 3r, 5R, 7S) -3-hydroxyadamantan-1-yl (meth) acrylate, (1s, 3R, 5R, 7s) (meth) acrylic acid ) -3,5-dihydroxyadamantan-1-yl, (meth) acrylic acid (3s, 5s, 7s) -adamantan-1-yl, (meth) acrylic acid (1s, 3s, 5R, 7S) ) -2-Methyladamantan-1-yl, (meth) acrylic acid (1s, 3s, 5R, 7S) -2-ethyladamantan-1-yl, (meth) acrylic acid (1r, 3r, 5r, 7r)- 2-ethyladamantan-2-yl, (meth) acrylic acid (1r, 3r, 5r, 7r) -2-isopropyladamantan-2-yl, (meth) acrylic acid {(3r, 5r, 7r) -adamantan-1 Monofunctional (meth) acrylic acid cyclic esters such as -yl @ methyl, 1-{(3r, 5r, 7r) -adamantan-1-yl} ethyl (meth) acrylate;

  For example, N-cyclohexyl (meth) acrylamide, N, N-diethyl-3-cyclohexyl (meth) acrylamide, (Z) -N, N-dimethyl-3- (cyclohexyl) (meth) acrylamide, N-cyclohexyloxymethyl ( Monofunctional acrylamides such as (meth) acrylamide, N-cyclohexyloxyethyl (meth) acrylamide, N-cyclohexyloxypropyl (meth) acrylamide, N-cyclohexyloxycybutyl (meth) acrylamide, N-cyclohexyloxidedecyl (meth) acrylamide Kind;

  For example, cyclohexyl vinyl ether, cycloxylmethyl vinyl ether, cyclohexylethyl vinyl ether, menthyl vinyl ether, 1,2-cyclohexane dimethanol monovinyl ether, 1,3-cyclohexane dimethanol monovinyl ether, 1,4-cyclohexane dimethanol monovinyl ether, 4-vinyl Monofunctional such as -1-cyclohexene, isobonyl vinyl ether, 5-vinylbicyclo [2.2.1] hepta-2-ene (alias: 5-vinyl-2-norbornene), 1-adamantyl vinyl ether, and 2-adamantyl vinyl ether Cyclic vinyl ethers;

  For example, 5-vinyl-2-norbornene, 5-vinyl-2,3-oxiranorbornane, 2- (2-propenyl) bicyclo [2.2.1] heptane, 5-vinylbicyclo [2.2.1] hepta -2-ene, 2,5-bis {(meth) allyloxy} norbornane, cyclohexyl (meth) allyl, 1,2-cyclohexanedimethanol mono (meth) allyl ether, 1,3-cyclohexanedimethanol mono (meth) allyl Monofunctional cyclic vinyl compounds and cyclic (meth) allyl compounds such as ether, 1,4-cyclohexanedimethanol mono (meth) allyl ether, 2-ethenylidene adamantane and 1- (meth) allyl adamantane;

  For example, 1,4-cyclohexanediol di (meth) acrylate, 2,5-norbornanediol di (meth) acrylate, 1,4-cyclohexanedimethanol di (meth) acrylate, 1,4-cyclohexanedimethanol di (meth) acrylate 4-cyclohexenediol, 1,4-cyclohexene dimethanol di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, hexahydrophthalic acid di (meth) acrylate, tricyclo di (meth) acrylate Decane dihydroxymethyl, tricyclodecane dihydroxymethyl dicaprolactate di (meth) acrylate, 2-methyl-1,1'-tricyclo [3,3,1,13,7] decane-1 di (meth) acrylate 1,3-diyl, 1,2-adamantanediol di (meth) acrylate, di (meth) acrylic acid 1 3-adamantanediol, 1,4-adamantanediol di (meth) acrylate, 1,2-adamantane dimethanol di (meth) acrylate, 1,3-adamantane dimethanol di (meth) acrylate, di (meth) acrylate Bifunctional (meth) acrylic acid cyclic diesters such as acrylic acid hexahydrophthalic acid;

  For example, bifunctional cyclic divinyl compounds such as 1,4-cyclohexane dimethanol divinyl ether, 1,4-cyclohexane dimethanol di (meth) allyl ether, 1,3-divinyl adamantane, and 2,2-divinyl adamantane, (Meth) allyl compounds. These may be used alone or in combination of two or more.

Since the compound (b1) exhibits hydrophobicity, a nonpolar monomer having 1 to 3 ring structures is preferable, and the compound (b1) is used as a monomer unit constituting a copolymer. Can be introduced into the copolymer resin (B). Further, the compound (b1) preferably has no aromatic ring. By not having an aromatic ring, it becomes possible to introduce a hydrophobic unit into the copolymer resin (B) without impairing the flexibility of the ethylene oxide unit.
An aqueous pressure-sensitive adhesive obtained by mixing such an aqueous dispersion of tackifier resin containing the copolymer resin (B) with a base polymer (P) described below is applied, and the resulting pressure-sensitive adhesive sheet is used as a polyolefin plate. Even if it is adhered to an adherend having a low polarity, a high-strength adhesive force can be maintained. In addition, even if the adhesive sheet is adhered to the adherend and exposed to humidified heat for a long period of time, it exhibits high cohesion due to molecular orientation in addition to hydrophobicity, so it is a deterioration phenomenon such as foaming, floating and peeling. Is significantly suppressed.

<<< ethylenically unsaturated compound having ethylene oxide unit (b2) >>>
Next, the ethylenically unsaturated compound (b2) having an ethylene oxide unit will be described.
The ethylenically unsaturated compound (b2) having an ethylene oxide unit is a compound having two or more repeating unit ether bonds in the molecule. Here, the ethylene oxide unit contained in the compound (b2) refers to a repeating unit (also referred to as an addition mole number) of ethylene oxide (EO, a unit unit of ethylene oxide may be abbreviated as “EO”). It shows that it has two or more.
When the compound (b2) has an ethylene oxide unit, aqueous dispersion of the tackifier resin (A) is facilitated. The number of moles of the ethylene oxide unit (EO) added is preferably 2 to 100, more preferably 4 to 80, and still more preferably 4 to 60. When the EO addition mole number is in the above range, the copolymer resin (B) has flexibility, so that it is possible to improve the curved surface adhesion. Note that oxygen atoms of esters and ethers are also included in the ethylene oxide unit.

  Examples of such a compound (b2) include diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, and polyoxyethylene polyoxyethylene mono (meth) acrylate. (EO addition mole number: 5 to 30), mono (meth) acrylate poly (oxyethylene oxypropylene) (EO addition mole number: 2 to 30), mono (meth) acrylate poly (oxyethylene oxytetramethylene) ) (EO addition moles: 2 to 30), ethylene oxide addition (meth) acryl obtained by repeatedly adding ethylene oxide such as poly (oxyethylene oxybutylene) mono (meth) acrylate (EO addition moles: 2 to 30) Aliphatic (meth) acrylic acid containing hydroxyl groups such as acid esters Ethers;

  For example, ethylene oxide addition systems having a hydroxyl group at the terminal where ethylene oxide is repeatedly added, such as diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, tetraethylene glycol monovinyl ether, and polyoxyethylene monovinyl ether (EO addition mole number: 5 to 30). Hydroxyl group-containing aliphatic vinyl ethers such as vinyl ether;

  For example, diethylene glycol mono (meth) allyl ether, triethylene glycol mono (meth) allyl ether, tetraethylene glycol mono (meth) allyl ether, polyoxyethylene mono (meth) allyl ether (EO addition mole number: 5 to 30), and the like Hydroxyl group-containing aliphatic (meth) allyl ethers such as ethylene oxide addition type (meth) allyl ether having a hydroxyl group at the terminal to which ethylene oxide is added repeatedly;

  For example, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxypolyoxyethylene (meth) acrylate (number of moles of added EO: 4 to 40), methoxypolyoxyethylene (meth) acrylate. Polyoxypropylene (number of moles of EO addition: 2 to 30, number of moles of PO added: 1 to 20), ethoxydiethylene glycol (meth) acrylate, ethoxytriethylene glycol (meth) acrylate, ethoxypolyoxyethylene (meth) acrylate (EO added moles: 4 to 40), ethoxy polyoxyethylene / polyoxypropylene (meth) acrylate (EO added moles: 2 to 30, PO added moles: 1 to 20), butoxy (meth) acrylate Diethylene glycol, (meth) acrylic acid bute Citriethylene glycol, butoxypolyoxyethylene (meth) acrylate (number of moles of added EO: 4 to 40), hexyloxypolyoxyethylene (meth) acrylate (number of moles of added EO: 2 to 40), (meth) acrylic acid 2-ethylhexyloxy polyoxyethylene (EO addition mole number: 2 to 40), octyloxy polyoxyethylene (meth) acrylate (EO addition mole number: 2 to 40), decyloxy polyoxyethylene (meth) acrylate ( Number of moles of EO added: 2 to 40), lauryloxy polyoxyethylene (meth) acrylate (number of moles of added EO: 4 to 40), octyloxy polyoxyethylene polyoxypropylene (meth) acrylate (number of moles of EO added: (2-40) and the like containing an ethylene oxide unit having an alkoxy group ( Data) acrylic acid esters;

  For example, diethylene glycol methyl vinyl ether, diethylene glycol ethyl vinyl ether, diethylene glycol butyl vinyl ether, triethylene glycol methyl vinyl ether, triethylene glycol ethyl vinyl ether, triethylene glycol butyl vinyl ether, polyoxyethylene methyl vinyl ether (EO addition moles: 4 to 30), polyoxy Vinyl ethers containing an ethylene oxide unit having an alkoxy group such as ethylene ethyl vinyl ether (EO addition mole number: 4 to 30), polyoxyethylene butyl vinyl ether (EO addition mole number: 4 to 30);

  For example, diethylene glycol methyl (meth) allyl ether, diethylene glycol ethyl (meth) allyl ether, diethylene glycol butyl (meth) allyl ether, triethylene glycol methyl (meth) allyl ether, triethylene glycol ethyl (meth) allyl ether, triethylene glycol butyl (Meth) allyl ether, polyoxyethylene methyl (meth) allyl ether (EO addition moles: 4 to 30), polyoxyethylene ethyl (meth) allyl ether (EO addition moles: 4 to 30), polyoxyethylene butyl (Meth) allyl ethers containing an ethylene oxide unit having an alkoxy group such as (meth) allyl ether (number of moles of added EO: 4 to 30);

  For example, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyoxyethylene di (meth) acrylate (number of moles of EO added: 5 to 40), Polyoxyethylene-added trimethylolpropane tri (meth) acrylate (EO addition moles: 3 to 30), polyoxyethylene-added pentaerythritol tetra (meth) acrylate (EO addition moles: 3 to 30), Many ethylene oxide unit-containing such as (meth) acrylic acid isocyanuric acid ethylene oxide modified (EO added mole number: 2 to 30), tri (meth) acrylic acid isocyanuric acid ethylene oxide modified (EO added mole number: 2 to 30), etc. Functional (meth) acrylates;

  For example, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, polyethylene glycol divinyl ether (EO addition mole number: 5 to 30), polyoxyethylene addition trimethylolpropane trivinyl ether (EO addition mole number: 3 to 3) 30) polyfunctional vinyl ethers containing ethylene oxide units such as polyoxyethylene-added pentaerythritol tetravinyl ether (EO added mole number: 3 to 30);

  For example, diethylene glycol di (meth) allyl ether, triethylene glycol di (meth) allyl ether, tetraethylene glycol di (meth) allyl ether, polyethylene glycol di (meth) allyl ether (EO added mole number: 5 to 30), poly Ethylene oxide units such as oxyethylene-added trimethylolpropane tri (meth) allyl ether (EO addition mole number: 3 to 30), polyoxyethylene addition pentaerythritol tetra (meth) allyl ether (EO addition mole number: 3 to 30) Contained polyfunctional (meth) allyl ethers and the like, but are not particularly limited thereto. One of these may be used alone, or a plurality of them may be used in combination.

It is preferable that the compound (b2) does not have an aromatic ring from the viewpoint of improving adhesion to a substrate and maintaining curved surface adhesion. In addition, since the copolymer resin (B) is easily emulsified in water, the aqueous dispersion of the tackifier resin (A) is facilitated, and the separation is suppressed even when left over time. Further, it is possible to further maintain water resistance and wet heat resistance.
In addition, the tackifier resin aqueous dispersion containing the copolymer resin (B) also has improved compatibility with the base polymer (P) described below, and the aqueous tackifier containing the approximately tackifier resin aqueous dispersion is: Various physical properties such as good adhesive strength, various resistances, and flexibility can be appropriately controlled.

<< carboxyl group-containing ethylenically unsaturated compound (b3) >>
Subsequently, the carboxyl group-containing ethylenically unsaturated compound (b3) will be described.
The carboxyl group-containing ethylenically unsaturated compound (b3) is a compound having a carboxyl group or its acid anhydride group ((-C = O) -O- (C = O)-) in the molecule. . When the copolymer resin (B) has a carboxyl group or an acid anhydride group thereof by the compound (b3), aqueous dispersion of the tackifier resin (A) is facilitated. In addition, the aqueous pressure-sensitive adhesive containing the approximately aqueous tackifier resin dispersion can maintain good adhesive strength and heat-resistant holding power.
Examples of such a compound (b3) include (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, 2-carboxypropyl (meth) acrylate, 3-carboxypropyl (meth) acrylate, and (meth) acrylate. ) 4-carboxybutyl acrylate, (meth) acrylic acid dimer, maleic acid, fumaric acid, monomethylmaleic acid, monomethylfumaric acid, aconitic acid, sorbic acid, cinnamic acid, α-chlorosorbic acid, glutaconic acid, citraconic acid , Mesaconic acid, itaconic acid, tiglic acid, angelic acid, senecioic acid, crotonic acid, isocrotonic acid, mucobromic acid, mucochloric acid, muconic acid, aconitic acid, penicillic acid, gellanic acid, citronellic acid, 4-acrylamidobutanoic acid, 6 -Acrylamidohexanoic acid, 2- (meth) acryloyl Polylactone (meth) acrylates having a carboxyl group at the terminal by ring-opening addition of a lactone ring, such as ethyl succinate, mono (meth) acrylic acid ω-carboxypolycaprolactone ester, ethylene oxide and propylene oxide. An aliphatic α, β-unsaturated double bond group containing a carboxyl group such as an ester of an alkylene oxide-added succinic acid having a carboxyl group at the terminal and (meth) acrylic acid to which an alkylene oxide is repeatedly added. Carboxylic acids and their anhydrides may be used. These may be used alone or in combination of two or more, but are compatible with the base polymer (P) shown below. It is preferable not to have an aromatic ring from the viewpoint of maintaining the curved surface adhesiveness.

<< other ethylenically unsaturated compounds (b4) >>
Next, the other ethylenically unsaturated compound (b4) will be described.
Other ethylenically unsaturated compounds (b4) are ethylenically unsaturated compounds other than the above-mentioned compounds (b1), (b2) and (b3).
The compound (b4), the compound (b2) or the compound (b2), which is a monomer unit constituting the copolymer resin (B), is used as necessary as a part of the constituent monomer of the compound (b4). In some cases, it is easy to increase the efficiency of the copolymerization reaction with (b3). In addition, the viscosity of the copolymer resin (B) can be reduced, and the workability during emulsification of the tackifier resin (A) can be easily improved.
Further, the weight average molecular weight (hereinafter may be abbreviated as “Mw”), acid value (hereinafter may be abbreviated as “AV”), or viscosity (hereinafter “Vis”) of the copolymer resin (B). (May be abbreviated as "abbreviated"), which facilitates aqueous dispersion of the tackifier resin (A). In addition, the tackifier resin aqueous dispersion containing the copolymer resin (B) also has improved compatibility with the base polymer (P) described below, and the aqueous tackifier containing the approximately tackifier resin aqueous dispersion is: Various physical properties such as good adhesive strength, various resistances, and flexibility can be appropriately controlled.

  As such a compound (b4), for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, ( Cetyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth) ) 1-butenyl acrylate, 1,3-methyl-3-butenyl (meth) acrylate, (methoxycarbonyl) methyl (meth) acrylate, glycidyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, ( Sulfophenoxyethyl (meth) acrylate, perfluoromethyl (meth) acrylate, 3- Meth) acryloyloxy propyl and methyl dimethoxy silane (meth) acrylate;

  Vinyl esters such as vinyl acetate and vinyl propionate; N-substituted vinyl compounds such as N-vinyl pyridine, N-vinyl carbazole, N-vinyl-2-pyrrolidone, N-vinyl phthalimide; (meth) acrylamide, dimethyl (meth) ) Acrylamides such as acrylamide and diacetone acrylamide; α-olefins such as 1-butene, 4-methyl-1-pentene, 1-octene, 1-decene and 1-dodecene; (meth) acrylonitrile, styrene and the like. These may be used singly or in combination of two or more, but they are used for maintaining the compatibility with the base polymer (P), the adhesion to the base material, and the maintenance of the curved surface adhesion shown below. From the viewpoint, it is preferable not to have an aromatic ring.

<< copolymer resin (B) >>
The copolymer resin (B) is a copolymer resin having an alicyclic structure and an ethylene oxide unit. For example, the compound (b1) and the compound (b2) and, if necessary, the compound (b3) and the compound (b) b4) can be obtained by copolymerization. Among the above monomers, a compound having a (meth) acryloyl group is preferred from the viewpoint of reactivity. In various ethylenically unsaturated compounds, control of the viscosity and emulsifiability of the copolymer resin (B), particle size and storage stability of the tackifier resin aqueous dispersion, adhesion and durability of the pressure-sensitive adhesive sheet are thus described. Alternatively, the compound (b1), the compound (b2), and the compound (b3) and, if necessary, the compound (b4) can be selected based on the suitability for coating and the like.

  The copolymer resin (B) is generally prepared by adding 0.001 to 20 parts by mass of a polymerization initiator to 100 parts by mass of the monomer mixture of various ethylenically unsaturated compounds as described above. It is synthesized by a method such as bulk polymerization, solution polymerization, emulsion polymerization, or suspension polymerization. Although there is no particular limitation on these polymerization methods and reaction operations, bulk polymerization and high-pressure polymerization are preferred. In the case of bulk polymerization, since a solvent is not used at all, a high polymerization reaction rate can be expected, and it is possible to avoid the incorporation of excessive additives which greatly affect the physical properties. In the case of high-pressure polymerization, although a pressure vessel is required, a high polymerization reaction rate is possible even with a reaction liquid having a remarkably high viscosity. In addition, the molecular weight and viscosity can be controlled by the reaction temperature or the amount of the polymerization initiator in the bulk polymerization method, and by the reaction temperature and the degree of pressure in the high-pressure polymerization method. In the polymerization reaction, a basic compound (E) described below can be used in combination.

  Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane 1-carbonitrile), , 2'-Azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate) Dimethyl 2,2'-azobisisobutyrate, 1,1'-azobis (1-acetoxy-1-phenylethane), 4,4'-azobis (4-cyanovaleric acid), 2,2'- Examples include azo compounds such as azobis (2-hydroxymethylpropionitrile) and 2,2′-azobis [2- (2-imidazolin-2-yl) propane].

  Also, benzoyl peroxide, tert-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propylperoxydicarbonate, di (2-ethoxyethyl) peroxydicarbonate, tert-butylperoxy Organics such as -2-ethylhexanoate, tert-butylperoxyneodecanoate, tert-butylperoxybivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide and diacetyl peroxide Peroxides.

  In addition, at the time of synthesis, mercaptans such as lauryl mercaptan and n-dodecyl mercaptan, and chain transfer agents such as α-methylstyrene dimer and limonene may be used.

  Among these, from the viewpoint of controlling the molecular weight and controlling the molecular weight distribution, as the polymerization initiator, 2,2′-azobisisobutyronitrile, dimethyl 2,2′-azobis (2-methylpropionate), dimethyl 2,2 ′ 2'-azobisisobutyrate, 2,2'-azobis (2,4-dimethylvaleronitrile), dibenzoyldioxidane, tert-butyl perbenzoate, tert-butyl peroxypivalate, tert-hexyl peroxypi Valate, octanoyl peroxide, lauroyl peroxide and tert-butylperoxy-2-ethylhexanoate are preferred.

  The polymerization conditions for the polymerization reaction of the copolymer resin (B) may be appropriately set according to the polymerization method, and are not particularly limited. The polymerization temperature is preferably from 20 to 150C, more preferably from 40 to 120C. The reaction time may be appropriately set so that the polymerization reaction of each component of the ethylenically unsaturated compound is completed.

  The alicyclic structure contained in the copolymer resin (B) is introduced from the compound (b1), and preferably contains 2 to 25% by mass of the alicyclic structure in 100% by mass of the copolymer resin (B). , And more preferably 5 to 20% by mass. The ethylene oxide unit contained in the copolymer resin (B) is introduced from the compound (b2), and is preferably contained in an amount of 40 to 80% by mass in 100% by mass of the copolymer resin (B). More preferably, it is contained in an amount of about 70% by mass. When the content of the alicyclic structure and the ethylene oxide unit is in the above range, a hydrophobic non-polar part is present in a hydrophilic polar part, and it is possible to have an effective surface activity. Therefore, not only can the tackifying resin (A) be easily made water-soluble, but also the pressure-sensitive adhesive formed by coating from an aqueous pressure-sensitive adhesive using the tackifier resin aqueous dispersion containing the copolymer resin (B) of the present invention. It is also possible to maintain the moisture and heat resistance of the sheet and improve the adhesiveness.

Since the copolymer resin (B) has the alicyclic structure and the ethylene oxide unit described above, it is used as a monomer unit constituting the copolymer resin (B) in 100 parts by mass of the copolymer resin (B). ,
It is preferable to contain 10 to 30 parts by mass of the compound (b1), 55 to 80 parts by mass of the compound (b2), and 5 to 20 parts by mass of the compound (b3),
More preferably, the amount is within the range of 15 to 30 parts by mass of the compound (b1), 55 to 80 parts by mass of the compound (b2), and 5 to 15 parts by mass of the compound (b3).
The mass ratio of the compound (b1) to the compound (b2) is preferably in the range of 5:95 to 40:60, and more preferably in the range of 15:85 to 35:65.
When the content of each monomer is within the above range, the acid value (AV), the weight average molecular weight (Mw), and the glass transition temperature (hereinafter referred to as “Tg”) of the copolymer resin (B) ), Various physical properties such as adhesive strength, various resistances, flexibility, compatibility and emulsifying property can be appropriately controlled.

  The copolymer resin (B) has a glass transition point (Tg) of -50 to 20C, more preferably -45 to 10C, so that the copolymer resin (B) can exhibit good emulsifying properties. In addition, it is preferable to select the constituent ratio of each monomer which is a constituent component of the copolymer resin. When the Tg is within the above range, not only the emulsification of the tackifier resin (A) is facilitated but also the flexibility of the pressure-sensitive adhesive sheet obtained from the aqueous pressure-sensitive adhesive containing the aqueous tackifier resin dispersion is maintained. As it is, it is possible to maintain the workability such as punching and cutting.

Here, in the copolymer resin (B), the glass transition temperature (Tg) of the copolymer is determined using a differential scanning calorimeter (DSC) described later. If the Tg of a homopolymer that can be formed from each of the ethylenically unsaturated compounds is known, the copolymer weight is determined based on the glass transition temperature (Tg) of each of the homopolymers and the constitutional ratio of the ethylenically unsaturated compound. The Tg of the united resin (B) can be theoretically determined, and the Tg of the copolymer resin (B) can be theoretically calculated by the following FOX formula.
<FOX formula> 1 / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wi / Tgi + ... + Wn / Tgn
[The FOX formula is defined as Tgi (K), where Tgi (K) is the glass transition temperature of the homopolymer of each compound constituting the polymer comprising n kinds of α, β-unsaturated double bond group-containing compounds. The rate is Wi, and (W1 + W2 +... + Wi +... Wn = 1). ]

  Furthermore, the Tg of the homopolymer can use the value described in the literature. As such documents, for example, the following documents can be referred to: Acrylic ester catalog of Mitsubishi Rayon Co., Ltd. (2001 edition); Catalog of Osaka Organic Chemical Industry Co., Ltd. (2009 edition); And "POLYMER HANDBOOK", 3rd edition, pages 209-277, published by John Wiley & Sons, Inc. 1989. The Tg of the copolymer resin (B) in the present application is determined using a differential scanning calorimeter (DSC) described later. Details of the method for measuring the glass transition temperature (Tg) are described in Examples.

The weight average molecular weight (Mw) of the copolymer resin (B) is preferably in the range of 1,000 to 300,000, more preferably in the range of 2,000 to 100,000. The range of 000 to 50,000 is most preferred. Further, the acid value (AV) of the copolymer resin (B) is preferably in the range of 10 to 300, more preferably in the range of 40 to 200, and still more preferably 50 to 100 mgKOH / g. The acid value (AV) is a value measured according to JIS K0070: 1992.
When the weight average molecular weight (Mw) and the acid value (AV) are within the above ranges, the viscosity of the tackifier resin aqueous dispersion can be reduced and the emulsifiability can be improved. Control becomes easy in the range of 0.01 to 10 μm. Details of the method for measuring the acid value (AV) and the weight average molecular weight (Mw) are described in Examples.

  The aqueous tackifier resin dispersion of the present invention contains 0.5 to 50 parts by mass of the copolymer resin (B) and 1 to 30 parts by mass with respect to 100 parts by mass of the tackifier resin (A). Is preferred. When the copolymer resin (B) is within this range, the viscosity of the tackifier resin aqueous dispersion becomes low, workability is remarkably improved, and a stable aqueous dispersion can be obtained. Stability is improved. In addition, even when a water-based pressure-sensitive adhesive is contained in a base polymer described below, a stable water-based pressure-sensitive adhesive can be obtained without separation, thickening, or thinning when left over time. The pressure-sensitive adhesive sheet obtained after application and drying of the water-based pressure-sensitive adhesive exhibits good adhesiveness, and can improve curved surface adhesiveness and heat-resistant holding power.

<Liquid resin (C) having a number average molecular weight of 300 to 50,000>
Next, the liquid resin (C) having a number average molecular weight of 300 to 50,000 will be described.
In one embodiment of the aqueous tackifier resin dispersion of the present invention, the tackifier aqueous resin dispersion further has a number average molecular weight (hereinafter may be abbreviated as “Mn”) of 300 to 300 in addition to the above essential components. 50,000 liquid resin (C) (hereinafter, referred to as liquid resin (C)). The liquid resin is a resin that is liquid or paste at 25 ° C. However, the tackifying resin (A) and the copolymer resin (B) are not included.
The number average molecular weight (Mn) of the liquid resin (C) is 300 to 50,000, preferably 500 to 10,000. When the number average molecular weight (Mn) is in this range, the adsorbability to the tackifying resin (A) is increased, so that the dispersibility is improved, and the heat resistance can be maintained.
The liquid resin (C) is preferably contained in an amount of 0.1 to 50 parts by mass, more preferably 1 to 30 parts by mass, based on 100 parts by mass of the copolymer (A). When the liquid resin (C) is in this range, the dispersibility of the tackifier resin (A) is improved, and not only can the particle diameter be controlled with high accuracy, but also the tackifier resin aqueous dispersion, The storage stability of the aqueous pressure-sensitive adhesive containing the imparted resin aqueous dispersion can be compatible with the water resistance and wet heat resistance of the pressure-sensitive adhesive layer formed from the water-based pressure-sensitive adhesive.

Specific examples of such a liquid resin (C) include olefin polymers, cyclic olefins, polyols and liquid rosin esters, but from the viewpoint of compatibility, particularly unsaturated hydrocarbons having 4 to 5 carbon atoms. An olefin polymer, a cyclic olefin, or a liquid rosin ester obtained by polymerizing is preferred. Examples of the unsaturated hydrocarbon having 4 to 5 carbon atoms include 1-butene, isobutene, 2-butene, butadiene, 1-pentene, 2-pentene, isopentene, isoprene and the like. The polymerization may be performed by a known method, and radical polymerization, cationic polymerization, or the like can be employed.
As the liquid resin (C), a commercially available product can be used. As the olefin polymer, for example, NISSO-PB B-1000 (Mn = 1,200) NISSO-PB G-1000 (Mn = 1,400, Hydroxyl value: 68-78 mgKOH / g), NISSO-PB BI-2000 (Mn = 2,200), NISSO-PB GI-2000 (Mn = 1,500, hydroxyl value = 60-75 mgKOH / g) [More than Japan Soda Corporation];
LBR-302 (Mn = 5,500), LBR-361 (Mn = 5,500), L-SBR-820 (Mn = 8,500) [all manufactured by Kuraray Co.];
Nisseki polybutene LV-7 (Mn = 300), Nisseki polybutene LV-50 (Mn = 430), Nisseki polybutene LV-100 (Mn = 500), Nisseki polybutene HV-15 (Mn = 630), Nisseki Polybutene HV-35 (Mn = 750), Nisseki Polybutene HV-50 (Mn = 800) [all manufactured by JXTG Energy];
NOF polybutene 0N (Mn = 370), NOF polybutene 015N (Mn = 580), NOF polybutene 3N (Mn = 720), NOF polybutene 10N (Mn = 1,000) [manufactured by NOF CORPORATION];
RT2730 (Mn = 1,000) and RT2304 (Mn = 800) [all manufactured by HUNSTMAN].

Examples of the liquid rosin ester include superester L (Mn = 650, liquid rosin ester), superester A-18 (Mn = 700, liquid rosin ester), and KE-364C (Mn = 221, liquid modified rosin ester) [ Above, liquid rosin manufactured by Arakawa Chemical Industry Co., Ltd.];
Banbeam UV-22C (Mn = 3,800, rosin-modified epoxy acrylate) and Banbeam UV-500 (Mn = 4,200, rosin-modified epoxy acrylate) [the above is a liquid rosin manufactured by Harima Chemicals, Inc.].

  Examples of the cyclic olefin include PRIPOL2033 (Mn = 540, dimer diol) and PRIPOL1006 (Mn = 600, dimer acid) [all manufactured by CRODA Coatings & Polymers].

  Examples of the polyol include a polyether polyol, a polyester polyol, a polycarbonate polyol, a copolymer thereof, and other glycols.

<Surfactant (D)>
Next, the surfactant (D) will be described.
In one embodiment of the aqueous tackifier resin dispersion of the present invention, the aqueous tackifier resin dispersion may further contain a surfactant (D) in addition to the above essential components.
When the above-mentioned tackifier resin (A) is made into an aqueous dispersion, it is possible to contain a surfactant (D) from the viewpoint of emulsion stability.
The surfactant (D) is not particularly limited, and various known surfactants such as anionic, nonionic, cationic, and amphoteric can be used. Anionic surfactant or nonionic surfactant alone or It is preferable to contain them in combination. The content is 1 to 20 parts by mass, preferably 1 to 10 parts by mass, per 100 parts by mass of the tackifying resin (A). When the surfactant (D) is contained within the above range, it is possible to ensure the storage stability of the aqueous dispersion without impairing the water resistance and wet heat resistance of the adhesive layer.

  Examples of the anionic surfactant include organic sulfonic acids, alkali metal salts of sulfates, and ammonium salts. Specific examples thereof include alkylaryl sulfonates, alkyl (or alkenyl) sulfates, and polyoxyethylene. Alkyl (or alkenyl) ether sulfates, polyoxyethylene alkyl aryl ether sulfates, alkyl sulfosuccinates, alkyl diaryl ether disulfonic acids, and derivatives thereof.

  Examples of the nonionic surfactant include ether type or ether ester type nonionic surfactants such as alkyl or aryl polyoxyethylene ethers, polyoxyethylene fatty acid monoesters, polyoxyethylene glycerin fatty acid esters, and polyoxyethylene glycerin fatty acid esters. Nonionic interfaces of ester type such as oxyethylene fatty acid trimethylolpropane, polyoxyethylene fatty acid pentaerythritol, polyoxyethylene sorbitol fatty acid ester, fatty acid monoglyceride, fatty acid diglyceride, fatty acid triglyceride, fatty acid trimethylolpropane, fatty acid pentaerythritol, sorbitan fatty acid ester, etc. Activator, polyoxyethylene alkylamine, alkyl alkanolamide, lauric acid diethanolamide, polyoxy Chi Ren alkylamine monostearate, nonionic surfactants nitrogen-containing type such as polyoxyethylene stearic acid amide. These can be used alone or in combination of two or more.

<Basic compound (E)>
Next, the basic compound (E) will be described.
In one embodiment of the aqueous tackifier resin dispersion of the present invention, the aqueous tackifier resin dispersion may further contain a basic compound (E) in addition to the above essential components.
The carboxyl groups in the tackifying resin (A) or the copolymer resin (B) are partially or entirely neutralized by the basic compound (E), and the fine particles are formed by the electric repulsion between the generated carboxyl anions. Agglomeration between them is prevented, and stability is imparted to the aqueous dispersion.

The basic compound (E) may be used when synthesizing the copolymer resin (B), or may be used after neutralizing the tackifier resin (A) or the copolymer resin (B) in advance. An aqueous dispersion of the imparting resin may be prepared, may be blended when mixing the tackifying resin (A) and the copolymer resin (B), or may be used in combination.
Although it does not specifically limit as a basic compound (E), An inorganic salt, ammonia, an organic base, etc. are mentioned. Among the organic bases, an organic amine compound having a boiling point of 300 ° C. or less is preferable from the viewpoint of water resistance and wet heat resistance of the coating film. When the boiling point is 300 ° C. or lower, the resin film can be easily removed by drying, and the coating film has good water / moisture / heat resistance, and good adhesion and adhesion to a substrate. As described above, the basic compound (E) may be used at the time of the polymerization reaction for obtaining the copolymer resin (B).

  Specific examples of the organic amine compound include triethylamine, tributylamine, N, N-dimethylethanolamine, aminoethanol, N-methyl-N, N-diethanolamine, N, N-dimethylbenzylamine, isopropylamine, iminobispropylamine , Ethylamine, diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, dibutylamine, propylamine, methylaminopropylamine, 3-methoxypropylamine, monoethanolamine, morpholine, N-methylmorpholine, N -Ethylmorpholine, diazabicycloundecene and the like.

  Of these organic amine compounds, tertiary amines (e1), which have good scattering properties and do not easily remain in the coating film and are non-reactive with the copolymer resin (B), are particularly preferred, and are commercially available. Particularly preferred are triethylamine, tributylamine, N, N-dimethylethanolamine, N, N-dimethylbenzylamine, N-methylmorpholine, N-ethylmorpholine, diazabicycloundecene and the like. Basic compounds other than the tertiary amine (e1) are referred to as basic substances (e2).

  The content of the basic compound (E) may be 0.5 to 20.0 times equivalent to the total amount of carboxyl groups contained in the tackifier resin (A) and the copolymer resin (B). Preferably, 1.0 to 10.0 equivalents are more preferable. When the content of the basic compound (E) is in the above range, the drying time at the time of forming the coating film is short, and the stability of the aqueous dispersion can be improved.

<Other compounds (F)>
Next, the other compound (F) will be described.
In one embodiment of the aqueous tackifier resin dispersion of the present invention, the tackifier aqueous resin dispersion may further contain, in addition to the above essential components, other compounds (F) as long as the problem can be solved.
Other compounds (F) include the above tackifier resin (A), copolymer resin (B), liquid resin (C), surfactant (D), surfactant (D), basic compound (E), It is a compound other than the base polymer (P) and has a function of improving the stability and physical properties of the material by adding a small amount of a component. For example, curing agents, thickeners, plasticizers, preservatives, rust inhibitors, freeze-thaw stabilizers, pigments, colorants, fillers, wetting agents, antioxidants, flame retardants, storage stabilizers, ultraviolet absorption Agents, thixotropy-imparting agents, dispersion stabilizers, fluidity-imparting agents, film-forming auxiliaries, humectants, pH adjusters, leveling agents, hydrolysis inhibitors, defoamers and the like.
The other compound (F) can be further added to an aqueous pressure-sensitive adhesive described later.

<Tackifying resin aqueous dispersion>
Next, the tackifier resin aqueous dispersion will be described.
As described above, the tackifier resin aqueous dispersion of the present invention comprises a copolymer resin (B) and, if necessary, a liquid resin (C), a surfactant (D), a basic compound (E) and other compounds. It is obtained by emulsifying the tackifier resin (A) while coexisting (F).
Further, the tackifier resin aqueous dispersion preferably does not contain an organic solvent, even if it is contained due to residual organic solvent derived from raw materials, the content is preferably 1,000 ppm or less, more preferably 500 ppm or less. It is preferably at most 100 ppm.
The emulsification method is not particularly limited, and any of known emulsification methods, such as a high-pressure emulsification method, an inverse emulsification method, an ultrasonic emulsification method, and a solvent emulsification method, may be employed. In consideration of environmental issues in addition to the reduction of the amount of the solvent, it is preferable to employ a solventless inversion emulsification method that does not use an organic solvent. In the case of the solventless inversion emulsification method, the tackifier resin (A) is melted at a softening point or higher using various emulsifiers such as various mixers, colloid mills, high-pressure emulsifiers, and high-pressure discharge emulsifiers. Under pressure or pressure, the copolymer resin (B) and, if necessary, a liquid resin (C), a surfactant (D), a basic compound (E) and another compound (F) are premixed, By adding water and inverting the phase, an aqueous dispersion can be obtained.

  The non-volatile content of the aqueous dispersion of tackifier resin thus obtained is not particularly limited, but is usually adjusted appropriately and used so as to be about 20 to 70%. The average particle diameter of the obtained aqueous dispersion of tackifying resin is usually about 0.1 to 2 μm, and most of the particles are uniformly dispersed as particles of 1 μm or less. The aqueous dispersion has a white or milky white appearance, a pH value of about 5 to 11, and a viscosity of usually about 10 to 2,000 mPa · s.

<Aqueous adhesive>
The aqueous pressure-sensitive adhesive of the present invention contains the base polymer (P) and the above-mentioned aqueous dispersion of the tackifying resin.

<<< base polymer (P) >>
The base polymer (P) used in the present invention has a glass transition temperature (Tg) of −70 to 0 ° C., exhibits a tack (adhesion) at 25 ° C., and is mainly made of a resin aqueous solution used as a main component of an aqueous adhesive. It is a dispersion. The base polymer (P) is preferably at least one selected from the group consisting of an aqueous acrylic dispersion, an aqueous rubber dispersion, and an aqueous synthetic resin dispersion. One base polymer may be used alone, or two or more base polymers may be used in combination.
As the acrylic aqueous dispersion, those generally used for various acrylic pressure-sensitive adhesives and the like can be used. For example, an aqueous dispersion manufactured by polymerizing (meth) acrylic acid ester can be used. Can be.
As the rubber-based aqueous dispersion, various known ones used for an aqueous pressure-sensitive adhesive can be used. For example, natural rubber latex, styrene-butadiene copolymer latex, chloroprene latex and the like can be mentioned.
Further, the synthetic resin-based aqueous dispersion is a synthetic resin-based emulsion excluding the acrylic aqueous dispersion, and various known ones used for water-based pressure-sensitive adhesives can be used. Examples thereof include synthetic resin-based aqueous dispersions such as vinyl acetate-based aqueous dispersion, ethylene-vinyl acetate copolymer-based aqueous dispersion, and urethane-based aqueous dispersion.

  The acrylic aqueous dispersion is synthesized according to a standard method using 0.001 to 20 parts by mass of a polymerization initiator based on 100 parts by mass of the total amount of the monomer mixture. For example, azo compounds such as 2,2′-azobis (2-methylpropionamidine) dihydrochloride and 2,2′-azobis (2-amidinopropane) dihydrochloride, and persulfates such as potassium persulfate and ammonium persulfate; Peroxides such as benzoyl peroxide, t-butyl hydroperoxide and hydrogen peroxide can be used. Also, a redox initiator composed of a combination of a persulfate and sodium bisulfite or a combination of a peroxide and sodium ascorbate can be used. Usually, a predetermined amount of these polymerization initiators may be added at each stage of the emulsion polymerization so that the polymerization reaction is carried out.

  In the aqueous pressure-sensitive adhesive of the present invention, the combination ratio of the base polymer (P) and the tackifier resin aqueous dispersion is not particularly limited, but the effect of modification by the tackifier resin aqueous dispersion can be sufficiently exhibited, and An appropriate use range that does not cause a decrease in heat resistance, tackiness, and the like due to excessive use is, based on 100 parts by mass (in terms of nonvolatile components) of the base polymer (P), usually 1 to 100 parts by mass of the tackifier resin aqueous dispersion. Parts (in terms of nonvolatile content).

  It is preferable that the viscosity of the aqueous pressure-sensitive adhesive of the present invention is appropriately adjusted according to the use form. The water-based pressure-sensitive adhesive of the present invention may additionally use water, if necessary, to adjust the viscosity. Further, the viscosity can be reduced by heating the aqueous pressure-sensitive adhesive without using additional moisture.

When forming a pressure-sensitive adhesive layer using the aqueous pressure-sensitive adhesive of the present invention, the thickness of the pressure-sensitive adhesive layer is preferably 0.5 to 100 μm, more preferably 1 to 50 μm. When the film thickness is in the above range, a sufficient adhesive strength can be obtained.
Therefore, from the viewpoint of coating film formation, the viscosity of the aqueous pressure-sensitive adhesive is preferably from 500 to 15,000 mPa · s when measured with a B-type viscometer at 25 ° C. More preferably, the range is from 10,000 mPa · s to 10,000 mPa · s. When the viscosity is 15,000 mPa · s or less, a thin film having a thickness of 0.5 to 100 μm can be easily formed on the substrate by coating, and it is also easy to increase the tacky properties such as tack, adhesive strength and holding power. It is. On the other hand, when the viscosity is 500 mPa · s or more, it is easy to control the thickness of the pressure-sensitive adhesive layer formed from the aqueous pressure-sensitive adhesive. In the present embodiment, the thickness, viscosity, or nonvolatile content of the pressure-sensitive adhesive layer is set according to the use of the laminate.

  The viscous pressure-sensitive adhesive of the present invention may further contain the above-mentioned other compound (F) in addition to the above-mentioned essential components as long as the problem can be solved.

<Adhesive sheet>
Next, the pressure-sensitive adhesive sheet will be described.
The pressure-sensitive adhesive sheet (also referred to as a pressure-sensitive adhesive film) of the present application is obtained by forming a pressure-sensitive adhesive layer composed of the above-described water-based pressure-sensitive adhesive on a substrate described later, and a sheet-shaped substrate having a surface subjected to a release treatment (also referred to as a release liner). ) May be stacked.
When manufacturing the pressure-sensitive adhesive sheet, in an appropriate manner according to a conventional method, after applying an aqueous pressure-sensitive adhesive to a substrate described below, water is removed by a method such as heating, and a pressure-sensitive adhesive layer is formed on the substrate. Can be formed. For example, there is a method in which an aqueous pressure-sensitive adhesive is applied to a release-treated surface of a release liner, dried, and a base material is attached to the release liner.

  The method for applying the aqueous pressure-sensitive adhesive is not particularly limited. For example, various known methods such as a Meyer bar, applicator, brush, spray, roller, gravure coater, die coater, kiss coater, lip coater, comma coater, blade coater, knife coater, reverse coater, spin coater, dip coater, etc. Can be applied. Further, the form of thin film coating or thick film coating can be selected without any particular limitation according to the application.

  The basic lamination structure of the pressure-sensitive adhesive sheet is a single-sided pressure-sensitive adhesive sheet such as a substrate / pressure-sensitive adhesive layer / release liner, or a double-sided pressure-sensitive adhesive sheet such as a release liner / pressure-sensitive adhesive layer / substrate / pressure-sensitive adhesive layer / release liner. . The laminate thus laminated on the release liner is called an adhesive sheet. During use, the release liner is peeled off, and the pressure-sensitive adhesive layer is adhered to the adherend. The water-based pressure-sensitive adhesive is not only an adhesive layer having the adhesive property at the moment when the pressure-sensitive adhesive layer touches the adherend at the time of application, but also an adhesive other than the adhesive (hereinafter simply referred to as an adhesive). On the other hand, it is necessary to have a cohesive force for maintaining the adhered state while maintaining the adhered state without completely solidifying even during the adherence and having a tack and moderate hardness. The cohesion greatly depends on the molecular weight and the crosslink density. The laminate thus laminated in the configuration of the base material / adhesive layer / adherend is referred to as an adhesive laminate.

  The pressure-sensitive adhesive sheet using the water-based pressure-sensitive adhesive of the present invention is used for a wide range of applications such as various known pressure-sensitive adhesive products (labels, seals, tapes, stickers, etc.). One of the materials forms a pressure-sensitive adhesive layer in which a base material of the pressure-sensitive adhesive sheet and a substrate (hereinafter referred to as an adherend) to which the other of the substrates are bonded are bonded. The water-based pressure-sensitive adhesive of the present invention is generally used for building materials used for bonding materials such as concrete, cement mortar, various metals, leather, glass, PVC sheets, decorative paper, plywood panels, gypsum boards, ceilings, etc. It is used for automotive interior parts such as materials, decorative parts, door rims, seats, instrument panels, dash silencers, center consoles, pillar trims, rear parcels, etc., and wire coating materials such as binding tape for wires. Among these, it is particularly preferable to use those used for a poorly adherent substrate.

Non-adhesive substrates include foam substrates having pores such as polyolefin foams, soft polyethers, soft polyesters, rigid polyethers, rigid polyester polyurethane foams, and vinyl chloride foams;
Polyethylene, polypropylene, poly-1-butene, polyisobutylene, ethylene-propylene copolymer, propylene-1-butene copolymer or block copolymer, ethylene-propylene-diene terpolymer, polymethylpentene, cyclo Olefin-based resin base materials such as a copolymer of pentadiene and ethylene and / or propylene;
Plastic resin substrates such as PET (polyethylene phthalate resin), PBT (polybutylene terephthalate resin), PVC (vinyl chloride resin), nylon, PC (polycarbonate resin), polyarylate resin, and PPS (polyphenylene sulfide resin). Can be The tackifier resin aqueous dispersion contained in the aqueous pressure-sensitive adhesive of the present invention exhibits excellent adhesion to a poorly adherent substrate.

  As described above, examples of the release liner include those obtained by subjecting the surface of a sheet-like substrate such as cellophane, various plastic sheets, paper, and metal foil to a release treatment. Further, as the sheet-shaped substrate, a single-layered substrate or a multi-layered substrate formed by laminating a plurality of substrates can be used.

  Hereinafter, specific examples of the present invention will be described together with comparative examples, but the present invention is not limited to the following examples. In the following Examples and Comparative Examples, “parts” and “%” represent “parts by mass” and “% by mass”, respectively, unless otherwise specified.

<Synthesis of copolymer resin (B)>
(Synthesis example 1)
Polymerization tank, stirrer, thermometer, reflux condenser, dropping device, the following monomer, polymerization initiator and basic compound in the following ratio to the polymerization tank and the dropping device of the polymerization reaction device equipped with a nitrogen inlet tube, respectively. I charged.

[Polymerization tank]
1-methyl-1-cyclopentyl acrylate (b1) 5.22 parts Methacrylic acid (b3) 2.91 parts Triethylamine (e1) 6.59 parts V65 (polymerization initiator) 0.24 parts
[Drip device]
1-methyl-1-cyclopentyl acrylate (b1) 12.18 parts Methoxypolyoxyethylene acrylate (b2) 72.8 parts Methacrylic acid (b3) 6.79 parts Triethylamine (e1) 15.37 parts V-65 (polymerization) Initiator) 0.56 parts

  After replacing the air in the polymerization tank with nitrogen gas, the mixture was heated to 80 ° C. while stirring under a nitrogen atmosphere to start polymerization. The mixture containing the ethylenically unsaturated compound, the basic compound (E) and the polymerization initiator was dropped from the dropping device at reflux temperature over 2 hours. After completion of the dropwise addition, 0.1 part of a polymerization initiator was added twice every hour while stirring, and the reaction was continued for 3 hours. Thereafter, 11.38 parts of triethylamine (e1) was added, and the mixture was cooled to 25 ° C. to obtain an amine solution of the copolymer resin (B). This solution was transparent and yellow, had a nonvolatile content concentration (NV) of 75.3%, a solution viscosity (Vis) of 750 mPa · s (25 ° C.), and the copolymer resin (B) had a glass transition temperature (Tg) − At 41 ° C., the acid value (AV) of the copolymer was 63.5 mgKOH / g, and the mass average molecular weight (Mw) was 18,000.

<Synthesis Examples 2 to 27>
The synthesis was carried out in the same manner as in Synthesis Example 1 except that the types and the amounts of the monomers, the polymerization initiator, and the basic compound (E) constituting the copolymer resin were changed according to Table 1, respectively. The copolymer resins of Examples 2 to 25 were synthesized.
In addition, the compound (b1) and the compound (b3) described in Table 1 represent the total value (part) of the amounts charged in the polymerization tank and the dropping tank.
Among these, the copolymer resins obtained in Synthesis Examples 1 to 11 and 15 to 25 are copolymer resins (B), and the copolymer resins obtained in Synthesis Examples 12 to 14, 26 and 27 are copolymer resins. It is a copolymer resin (for a comparative example) which is not the united resin (B).
The solution appearance, nonvolatile content (NV), solution viscosity (Vis), acid value (AV), mass average molecular weight (Mw) and glass transition temperature (Tg) of the obtained copolymer resin were determined according to the methods described below. The results are shown in Table 1. In addition, the numerical value described in Table 1 is a total amount (part) including the amount charged to the polymerization tank and the amount charged to the dropping device and the like, unless otherwise specified, and a blank column indicates that it is not used.

<Production of tackifier resin aqueous dispersion>
(Production Example 1)
The following tackifier resin (A), copolymer resin (B), Ion-exchanged water and, if necessary, a surfactant (D), a surfactant (D), and a basic compound (E) were charged at the following ratios.

[Stirred tank]
D-160 (A) 100 parts Copolymer resin (B) obtained in Synthesis Example 1 10 parts
[Drip device 1]
N, N-dimethylbenzylamine (e1) 10 parts
[Drip device 2]
80 parts of ion exchange water

After replacing the air in the stirring tank with nitrogen gas, the temperature was raised to 180 ° C. in a nitrogen stream with stirring, and the mixture was heated and melted for 1 hour. Thereafter, the reaction temperature was cooled to 120 ° C., and then N, N-dimethylbenzylamine (e1) was dropped from the dropping device 1 in 0.5 hours. Further, the inside of the reaction system was vigorously stirred while being kept at 100 ° C., and ion-exchanged water was dropped from the dropping device 2 over 2 hours, and the phase was inverted to obtain an aqueous dispersion. Further, 16.7 parts of ion-exchanged water was added, the mixture was cooled to 25 ° C., and filtered with a 180-mesh furnace cloth to obtain an aqueous dispersion of a tackifier resin having a nonvolatile content of 50.1%. At this time, filterability, pot stainability, storage stability and mechanical stability as productivity were evaluated according to the methods described below, and the results are shown in Table 2.
The nonvolatile content (NV), solution viscosity (Vis), average particle size (Dm) and hydrogen ion index (pH) of the obtained tackifier resin aqueous dispersion were determined in accordance with the method described later. It was shown to.

(Production Examples 2 to 75)
Except that the types and amounts of the tackifying resin (A), the copolymer resin (B), and other materials were changed as necessary according to Table 2, the same procedures as in Production Example 1 were carried out to produce Production Examples 2 to 70, respectively. Was prepared. The liquid resin (C) was charged in a stirring tank, the basic compound (E) was charged in a dropping device 1, and ion-exchanged water and, if necessary, a surfactant (D) were charged in a dropping device 2, thereby producing the resin.
In Production Examples 73 to 75, the liquid resin (C) (Production Examples 73 and 74) and the surfactant (D) (Production Example 75) were used without using the copolymer resin (B).
The other compound (F) was added and mixed after cooling to 25 ° C. The numerical values shown in Table 2 represent "parts" unless otherwise specified, and blank columns indicate that they are not used.
Among these, the aqueous dispersions obtained in Production Examples 1 to 9, 14 to 23, 25 to 33, 37 to 43, 47 to 50, 53 to 67, 69, and 70 are the tackifier resin aqueous dispersions of the present invention. The aqueous dispersion obtained in Production Examples 10 to 13, 24, 34 to 36, 44 to 46, 51, 52, 68, and 71 to 75 is not the tackifier resin aqueous dispersion of the present invention. It is. The nonvolatile concentration (NV), solution viscosity (Vis), average particle size (Dm), hydrogen ion exponent (pH), and organic solvent content of the obtained aqueous dispersion were determined according to the methods described later, and the results were shown in Table 2. It was shown to. In addition, the ion-exchanged water shown in Table 2 represents the total value (part) of the amount charged into the dropping device 2 and the amount for adjusting the concentration of nonvolatile components. In Production Examples 34, 36, and 52, in addition to the above, a part of ion-exchanged water charged into the stirring tank was changed to toluene as an organic solvent. Production Examples 46 and 73 could not be made aqueous.

<Synthesis of base polymer (P)>
(Synthesis Example 101)
The following ethylenically unsaturated monomers, a chain transfer agent, a surfactant, and ion-exchanged water were charged into the stirring tank of a stirring apparatus equipped with a stirring tank, a stirrer, and a thermometer at the following ratios.

[Stirred tank]
2-ethylhexyl acrylate 81.94 parts Methyl methacrylate 10.18 parts 2-hydroxyethyl methacrylate 3.31 parts 4.58 parts acrylic acid 0.02 parts Octyl thioglycolate (chain transfer agent) 0.02 parts Reactive surface activity Agent 5.0 parts Ion exchange water 30.5 parts

  An aqueous dispersion of the monomer was obtained while stirring the inside of the stirring tank. Next, an aqueous dispersion of the following monomer and a polymerization initiator were respectively added to a polymerization tank, a stirrer, a thermometer, a reflux condenser, a dropping device, and a reaction tank and a dropping device of a polymerization reaction device equipped with a nitrogen inlet tube, respectively. It was charged at the ratio of

[Polymerization tank]
36.17 parts of ion exchange water
[Drip device]
Aqueous dispersion of the above monomer 0.05 part 3% potassium persulfate aqueous solution (polymerization initiator) 10 parts

After replacing the air in the polymerization tank with nitrogen gas, the temperature was raised to 80 ° C. while stirring under a nitrogen atmosphere, and 0.1% of a 3% aqueous solution of potassium persulfate was added as a nonvolatile component.
Five minutes later, the aqueous dispersion of the monomer and a 3% aqueous solution of potassium persulfate were dropped from the dropping device over 3 hours.
While maintaining the reaction temperature at 80 ° C., with further stirring, a 3% aqueous solution of potassium persulfate was added dropwise at an interval of 1.0 part every 0.5 hour after the completion of the dropwise addition, and then the mixture was aged for 2 hours to continue the reaction. did. Thereafter, the mixture was cooled to 25 ° C. and adjusted to pH = 7.5 with aqueous ammonia to obtain a base polymer (aqueous acrylic resin dispersion) having a nonvolatile content of 60%. The nonvolatile content (NV), the solution viscosity (Vis), and the average particle size (Dm) of the obtained base polymer were determined according to the methods described below. The results are shown in Table 3.

(Synthesis examples 102 and 103)
A base polymer (aqueous dispersion of an acrylic resin) was synthesized in the same manner as in Synthesis Example 101, except that the materials and the blending amounts described in Table 4 were changed. The nonvolatile content (NV), the solution viscosity (Vis), and the average particle size (Dm) of the obtained base polymer were determined according to the methods described below. The results are shown in Table 3.

《Solution appearance》
The appearance of the copolymer (B) solutions obtained in Synthesis Examples 1 to 25 was visually observed at 25 ° C. It is good if it is not extremely dark.

<< Non-volatile content (NV) >>
About 1 g of each of the copolymer resin solution or the aqueous dispersion of the base polymer obtained in each of the synthesis examples and the aqueous dispersion of the tackifier resin obtained in each of the production examples was weighed in a metal container, and placed in a 150 ° C. oven. After drying for 20 minutes, the residue was weighed and the residual ratio was calculated to obtain the nonvolatile content (solid content) (unit:%).

<< Solution viscosity (Vis) >>
The copolymer resin solution obtained in Synthesis Examples 1 to 27, the aqueous dispersion of the base polymer obtained in Synthesis Examples 101 to 103 or the aqueous dispersion of the tackifier resin obtained in Production Examples 1 to 75, respectively. The viscosity of the solution or the aqueous dispersion was measured using a B-type viscometer (TV-22, manufactured by Toki Sangyo Co., Ltd.) at 25 ° C. under the conditions of rotor Nos. 2 to 4, rotation speed of 0.5 to 100 rpm, and rotation for 1 minute. mPa · s).

《Average molecular weight》
For the copolymer resins obtained in Synthesis Examples 1 to 27, the number average molecular weight (Mn) and the mass average molecular weight (Mw) were measured using GPC (gel permeation chromatography) manufactured by Showa Denko KK. The determination of the number average molecular weight (Mn) and the mass average molecular weight (Mw) was based on the converted value of polystyrene as a standard substance.
Apparatus name: Showa Denko GPC (gel permeation chromatography) "Shodex GPC System-21"
Column: Tosoh GMHXL: 4, Tosoh HXL-H: 1 connected in series.
Mobile phase solvent: tetrahydrofuran (THF)
Flow rate: 1.0 ml / min Column temperature: 40 ° C

<< acid value (AV) >>
About the copolymer resin obtained in Synthesis Examples 1 to 27, about 1 g of a sample was precisely weighed and placed in a stoppered Erlenmeyer flask, and 100 ml of a mixed solution of toluene / ethanol (volume ratio: toluene / ethanol = 2/1) was added. Dissolved. To this, phenolphthalein TS was added as an indicator, and after holding for 30 seconds, titration was performed with a 0.1N alcoholic potassium hydroxide solution until the solution turned red.
The acid value was determined by the following equation. The acid value was a value in the dry state of the resin (unit: mgKOH / g).
Acid value (mgKOH / g) = {(5.611 × a × F) / S} / (nonvolatile concentration / 100)
Here, S: sampled amount (g)
a: consumption of 0.1N alcoholic potassium hydroxide solution (ml)
F: titer of 0.1N alcoholic potassium hydroxide solution

<< Glass transition temperature (Tg) >>
The glass transition temperature (Tg) of the copolymer resin obtained in Synthesis Examples 1 to 27 was measured using a robot DSC (differential scanning calorimeter, “RDC220” manufactured by Seiko Instruments Inc.) and “SSC5200 Disk Station” (manufactured by Seiko Instruments Inc.). Was connected and measured.
About 10 mg of a sample is placed in an aluminum pan, weighed, set on a differential scanning calorimeter, and kept at a temperature of 100 ° C. for 5 minutes using the same type of aluminum pan without a sample as a reference, and then using liquid nitrogen. It was quenched to 120 ° C. Thereafter, the temperature was raised at a rate of 10 ° C./min, and the glass transition temperature (Tg, unit: ° C.) was determined from the obtained DSC chart.

<< Average particle size (Dm) >>
The average particle diameter of the aqueous dispersion of the base polymer obtained in Synthesis Examples 101 to 103 and the aqueous dispersion of the tackifier resin obtained in Production Examples 1 to 75 was measured using "Microtrack" manufactured by Nikkiso Co., Ltd. . As the average particle size, a value of 50% of the cumulative percentage was applied.

<< Hydrogen ion index (pH) >>
The pH obtained from the aqueous dispersion of the base polymer obtained in Synthesis Examples 101 to 103 or the aqueous dispersion of the tackifier resin obtained in Production Examples 1 to 75 was F-52S manufactured by HORIBA, electrode: Model 6377-10D. It measured using.

<< Evaluation of filterability >>
The tackifier resin aqueous dispersions obtained in Production Examples 1 to 75 were filtered with a 180-mesh furnace cloth and evaluated in three stages. In the case of "○" or "△" evaluation, there is no problem in actual use.
：: prompt filtration, no residue at all. Good.
Δ: A little time is required for filtration, and a small amount of residue that does not affect the concentration of nonvolatile components remains. Available for practical use.
X: Filtration time is long and the residue is considerably large. The nonvolatile content concentration has decreased. Not practical.

《Evaluation of pot stain》
After the production of the tackifier resin aqueous dispersions obtained in Production Examples 1 to 75, a three-stage evaluation was performed on the state of adhesion of solids to the tank wall of the stirring tank and the washability with water. In the case of "○" or "△" evaluation, there is no problem in actual use.
：: No adhesion at all, and good cleaning performance Δ: Some adhesion of solid matter, but good cleaning performance Available for practical use.
X: Solid adhered much and could not be removed by washing. Not practical.

<< Evaluation of storage stability >>
The aqueous dispersion of tackifier resin obtained in Production Examples 1 to 75 was collected in a 225 ml mayonnaise bottle, stored at 25 ° C. for 1 month with a lid, and then the dispersoid and liquid layer of the aqueous dispersion ( The state of separation of the dispersion medium) was evaluated in three stages. In the case of "○" or "△" evaluation, there is no problem in actual use.
○: The aqueous dispersion does not separate when stored for one month. Good.
Δ: Separated after storage for 2 weeks or longer, but returned to a uniform aqueous dispersion by shaking. Available for practical use.
X: Separation after storage for less than 2 weeks, or does not return to a uniform aqueous dispersion even if shaken. Not practical.

《Evaluation of mechanical stability》
5 g of water was added to 50 g of the aqueous tackifier resin dispersion obtained in Production Examples 1 to 75 to dilute the mixture, and the mixture was filtered through a 300-mesh wire net, and 50 g of the resultant was used as a test sample. Using a Malon mechanical stability tester [manufactured by Tester Sangyo Co., Ltd.], a mechanical load was applied for 10 minutes at a temperature of 25 ° C., a load of 15 kg, and a rotation speed of 1,000 rpm, and the formed aggregates were reduced to 300 mesh. And the dry mass of the aggregate was calculated with respect to the initial dry mass of the aqueous dispersion, and the mechanical stability was evaluated in three stages based on the formation ratio (%) of the aggregate. In the case of "○" or "△" evaluation, there is no problem in actual use.
：: The generation rate of aggregates is less than 0.1%. Good.
Δ: The generation rate of aggregates is in the range of 0.1 to 1.0%. Available for practical use.
X: The generation rate of aggregates exceeds 1.0%. Not practical.
Here, the generation rate of the aggregate was calculated by the following method.
Aggregate generation ratio (%) = 100 × (mass of aggregate) / (initial mass of test sample)

<< Evaluation of solvent content >>
The aqueous dispersion of the tackifying resin obtained in Production Examples 1 to 75 was diluted with water to 1% by mass as necessary using gas chromatography [Shimadzu Corporation "Gas Chromatograph GC-8A"]. The resulting product was directly charged into the apparatus, and the content of the organic solvent was determined and evaluated in three steps. In the case of "○" or "△" evaluation, there is no problem in actual use. The detection limit is 100 ppm.
Carrier gas: nitrogen
Column packing material (GL Science)
: PEG-HT (5%)-Uniport HP (60/80 mesh)
Column size: diameter 3mm x 3m
Sample injection temperature (injection temperature): 180 ° C
Column temperature: 80 ° C
Internal standard substance: n-butanol]
：: The content of the organic solvent is less than 100 ppm (below the detection limit). Good.
Δ: The content of the organic solvent is in the range of 100 to 1,000 ppm. Available for practical use.
×: The content of the organic solvent exceeds 1,000 ppm. Not practical.

  Abbreviations of the materials used in each synthesis example and each production example are shown below. Numerical values indicate parts, blanks indicate no formulation, and “−” indicates unevaluated.

<Table 1>
-Compound (b1)
MCPA: 1-methyl-1-cyclopentyl acrylate, CHMA: cyclohexyl methacrylate, IBXMA: isobonyl methacrylate, DCPMA: dicyclopentanyl methacrylate, VNB: 5-vinyl-2-norbornene compound (b2)
MO9A: methoxypolyoxyethylene acrylate (number of moles of EO added: 9), MO9MA: methoxypolyoxyethylene methacrylate (number of moles of EO added: 9), OEPMA: octyloxypolyoxyethylene polyoxypropylene (EO added mole) Number: 8, PO addition mole number: 6), EOVE: Polyoxyethylene methyl vinyl ether (EO addition mole number: 8), PHEOA: Phenoxy polyoxyethylene acrylate (EO addition mole number: 2)
-Compound (b3)
AA: acrylic acid, EAA: 2-carboxyethyl acrylate, MAA: methacrylic acid Compound (b4)
2EHA: 2-ethylhexyl acrylate, LA: lauryl acrylate, BZMA: benzyl methacrylate, AAM: acrylamide Polymerization initiator V65: 2,2′-azobis (2,4-dimethylvaleronitrile) [Wako Pure Chemical Industries, Ltd. “V65”], PBO: tert-butylperoxy-2-ethylhexanoate [“Perbutyl O” manufactured by NOF Corporation]
・ Basic compound (E)
TEA: triethylamine, DBU: diazabicycloundecene, EA: 2-aminoethanol

<Table 2>
・ Tackifying resin (A)
D160: Polymerized rosin ester [Pencel D-160, manufactured by Arakawa Chemical Industries, softening point = 160 ° C], KT3: Polymerized rosin ester [Hariester KT-3, manufactured by Harima Chemicals, softening point = 180 ° C], KR140: hydrogenated rosin ester [Pine Crystal KR-140, manufactured by Arakawa Chemical Industries, softening point = 140 ° C], FTR: petroleum resin [FTR6125, manufactured by Mitsui Chemicals, softening point = 125 ° C], T160: Terpene / phenol resin [Yasuhara Chemical Co., Ltd. “YS Polystar T160”, softening point = 160 ° C]
-Tackifier resin not tackifier resin (A) E-H: Rosin ester [Arakawa Chemical Industries "Ester gum H", softening point = 68 ° C]
・ Copolymer resin (B)
Synthetic Examples: Compounds obtained in each of the Synthetic Examples shown in Table 2 (Synthetic Examples 1 to 27)
・ Liquid resin (C)
HV100: Polybutene [Nisseki polybutene HV-100, manufactured by JXTG Energy, Mn = 980], P1025: Dimer acid [Pripol1025, Mn = 560.9, manufactured by CRODA], P2010: Polyester polyol [Kuraray manufactured] Kuraray polyol P-2010 ", Mn = 2,000], UV22C: rosin-modified epoxy acrylate [" Banbeam UV-22C "manufactured by Harima Chemicals, Mn = 3,800]
・ Surfactant (D) (anion)
LAEOA: Polyoxyethylene lauryl ether ammonium sulfate (EO addition mole number: 20), SR20: Polyoxyethylene-1- (allyloxymethyl) alkyl ether glycerin sulfonate ammonium (EO addition mole number: 20) [ADEKASOAP manufactured by ADEKA CORPORATION SR20 "]
・ Surfactant (D) (nonionic)
STEO: polyoxyethylene stearyl ether (number of moles of EO added: 50)
-Basic compound (e1)
TEA: triethylamine, DMBA: N, N-dimethylbenzylamine Basic compound (e2)
EA: 2-aminoethanol • Water W: Ion exchange water • Organic solvent TOL: Toluene • Other compound (F)
KM73A: Silicone antifoaming agent [Shin-Etsu Silicone KM-73A manufactured by Shin-Etsu Chemical Co., Ltd.]

<Table 3>
Ethylenically unsaturated monomer BA: butyl acrylate, 2EHA: 2-ethylhexyl acrylate, MMA: methyl methacrylate, MA: methyl acrylate, HEMA: 2-hydroxyethyl methacrylate, AA: acrylic acid, DAAM: Diacetone acrylamide ・ Chain transfer agent SGO Octyl thioglycolate ・ Surfactant KH10: Reactive surfactant [[Aqualon KH-10 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.]
・ Polymerization initiator KPS: 3% potassium persulfate aqueous solution ・ Water W: Ion exchange water

  In addition, the mass described in the column of the polymerization initiator in Table 1 is the total of the mass added in the polymerization tank, the total of the mass added three times during the dropwise addition, and the post-addition is the total of the mass added twice after the completion of the dropwise addition. Means In addition, the mass described in the column of the polymerization initiator in Table 3 means the sum of the mass charged in the dropping tank and the mass added twice after the completion of the dropping.

<Aqueous adhesive>
Using the tackifier resin aqueous dispersions obtained in the above Production Examples, aqueous pressure-sensitive adhesives were respectively prepared by the following methods.
(Example 1)
In a stirring tank of a stirrer equipped with a stirrer, stirrer, and thermometer, the following base polymer, tackifier resin aqueous dispersion and other compound (F) {crosslinking agent, viscosity modifier, defoamer, and preservative} were respectively added. The following ratios were used.

[Stirred tank]
100 parts of base polymer (P) of Synthesis Example 101 10 parts of aqueous dispersion of tackifying resin of Production Example 1 10 parts 5% aqueous solution of adipic acid dihydrazide (crosslinking agent) 1.0 part Adecanol UH-420 (viscosity modifier) 0.4 Part SN deformer 154 (antifoaming agent) 0.1 part Deltop 100N (preservative) 0.01 part

  Using a homomixer (“LZB46-HM-3” manufactured by Chuo Rika Co., Ltd.) as a stirrer, the mixture was stirred for 0.5 hour at a rotation speed of 2,000 rpm. Next, while stirring, Acrysol ASE-60 (viscosity modifier), ammonia water and ion-exchanged water were added to adjust, and the non-volatile content (NV) was about 50% and the solution viscosity (Vis) was about 8,000 mPa · s. The pH was adjusted to about 8.2 to obtain an aqueous pressure-sensitive adhesive. The non-volatile content (NV), solution viscosity (Vis) and hydrogen ion index (pH) of the obtained water-based pressure-sensitive adhesive were determined according to the above-mentioned methods, and the results are shown in Table 4.

(Examples 2 to 70, Comparative Examples 1 to 19)
Among the materials described in Table 5, a base polymer, an aqueous dispersion of a tackifying resin, a crosslinking agent, a viscosity modifier, an antifoaming agent, and a preservative were blended according to the description in Table 4, and agitated and mixed. Obtained.
Each of the obtained water-based pressure-sensitive adhesives was applied to each substrate, dried and bonded, to prepare a pressure-sensitive adhesive sheet, which was evaluated by the following method. Table 6 shows the results. In Comparative Examples 11 and 17, production and coating of the aqueous pressure-sensitive adhesive were not performed because the filterability of the aqueous tackifier resin dispersion was extremely poor.

<< Evaluation of storage stability >>
The aqueous pressure-sensitive adhesive obtained in each of the examples and comparative examples was collected in a 225 ml mayonnaise bottle in the same manner as described above, and stored for 1 month at 25 ° C. with the lid covered. The state of separation of the layer (dispersion medium) was evaluated in three stages. In the case of "○" or "△" evaluation, there is no problem in actual use.
○: The aqueous dispersion does not separate when stored for one month. Good.
Δ: Separated after storage for 2 weeks or longer, but returned to a uniform aqueous dispersion by shaking. Available for practical use.

X: Separation after storage for less than 2 weeks, or does not return to a uniform aqueous dispersion even if shaken. Not practical.

《Evaluation of mechanical stability》
In the same manner as described above, 50 g of the aqueous pressure-sensitive adhesive obtained in each of the examples and comparative examples was collected, diluted with 5 g of water, filtered through a 300-mesh wire gauze, and 50 g thereof was used as a test sample. Using a Malon mechanical stability tester [manufactured by Tester Sangyo Co., Ltd.], a mechanical load was applied for 10 minutes at a temperature of 25 ° C., a load of 15 kg, and a rotation speed of 1,000 rpm, and the formed aggregates were reduced to 300 mesh. , And the dry mass of the aggregate was calculated with respect to the initial dry mass of the aqueous pressure-sensitive adhesive, and the mechanical stability was evaluated in three stages based on the generation ratio (%) of the aggregate. In the case of "○" or "△" evaluation, there is no problem in actual use.
：: The generation rate of aggregates is less than 0.1%. Good.
Δ: The generation rate of aggregates is in the range of 0.1 to 1.0%. Available for practical use.
X: The generation rate of aggregates exceeds 1.0%. Not practical.
Here, the generation rate of the aggregate was calculated by the following method.
Aggregate generation ratio (%) = 100 × (mass of aggregate) / (initial mass of test sample)

《Evaluation of coatability》
The obtained water-based pressure-sensitive adhesive is coated on a commercially available glassine paper (hereinafter also referred to as “glassine separator”) that has been subjected to a release treatment as a release liner so that the thickness of the pressure-sensitive adhesive layer after drying is 18 μm. Then, by drying with hot air at 100 ° C. for 2 minutes, an adhesive layer was formed. Then, a commercially available high-quality paper having a thickness of 60 μm was attached to the coated surface to produce an adhesive sheet composed of high-quality paper / adhesive layer / release liner. Then, the state of the pressure-sensitive adhesive layer surface (coated surface) after peeling off the release liner was visually observed and evaluated in three steps. In the case of "○" or "△" evaluation, there is no problem in actual use.
：: No smoothing, foaming or streaking was observed on the coated surface, and the coated surface was smooth. Good.
Δ: Slight repelling or foaming is observed at the end of the coated surface. Available for practical use.
×: Repelling, foaming and streaking were observed on the entire coated surface. Bad.

《Evaluation of workability》
Each of the pressure-sensitive adhesive sheets prepared in the same manner as in <Evaluation of Coating Properties> was cured for 3 days in an environment of 23 ° C. and 50% relative humidity. Thereafter, the sheet was cut into a piece having a width of 100 mm and a length of 100 mm. Twenty pieces of the pieces were stacked and pressed out under the condition of 40 ° C.-60 kg / cm ² for 1 hour. Was evaluated in three stages. In the case of "○" or "△" evaluation, there is no problem in actual use.
：: No protrusion of the pressure-sensitive adhesive layer was observed. Good.
Δ: Extrusion of the pressure-sensitive adhesive layer of less than 0.3 mm was observed, but practically usable.
×: Extrusion of the pressure-sensitive adhesive layer of 0.3 mm or more is observed. Bad.

<< Measurement of peel strength >>
Each of the pressure-sensitive adhesive sheets prepared in the same manner as in the above <Evaluation of coating property> is cut into a width of 25 mm × length of 100 mm, the release liner is peeled off, and the exposed pressure-sensitive adhesive layer is a polyethylene (PE) plate having a thickness of 3 mm. Was adhered in an environment of 23 ° C. and a relative humidity of 50%, and a roll having a mass of 2 kg was reciprocated once to obtain a measurement sample. After leaving this measurement sample for 1 day in an environment of 23 ° C. and 50% relative humidity, a peeling rate of 300 mm / min. Was used in the same environment using a tensile tester (“Tensilon” manufactured by Orientec). The peel strength was measured under the condition of an angle of 180 ° (measurement of the peel strength one day after bonding).
Further, after the measurement sample was left in an environment of 60 ° C. and a relative humidity of 95% for 3 days, the peel strength was measured in the same manner (measurement of the peel strength after 3 days of wet heat aging). The peel strength was evaluated as adhesive strength in three stages. In the case of "○" or "△" evaluation, there is no problem in actual use.
：: Adhesive strength is 20.0 (mN / 25 mm) or more. Good.
Δ: Adhesion force is 15.0 (mN / 25 mm) or more and less than 20.0 (mN / 25 mm). Practical.
×: Adhesive strength is less than 15.0 (mN / 25 mm). Bad and impractical.

《Measurement of holding force》
Each of the pressure-sensitive adhesive sheets prepared in the same manner as in the above <Evaluation of Coating Properties> was cut into a width of 25 mm x a length of 100 mm, and the release liner was peeled off so that the bonded portion became 25 mm x 25 mm. The layer was adhered to a stainless steel (SUS) plate having a thickness of 3 mm in an environment of 23 ° C. and a relative humidity of 50%, and a roll having a mass of 2 kg was reciprocated once to obtain a measurement sample.
After leaving this measurement sample in a 40 ° C. environment for 20 minutes, a load of 1 kg was applied in a 40 ° C. environment and 70,000 seconds at 40 ° C. using a holding force tester [manufactured by Tester Sangyo Co., Ltd.] The measurement was performed, and the time required for the load to fall, or when the load did not fall, was measured for the length deviated from the time of the initial attachment, and evaluated in the following three stages. In the case of "○" or "△" evaluation, there is no problem in actual use.
：: There is no load drop and the deviation is less than 0.5 mm. Good.
Δ: There is no load drop, but the deviation is 0.5 mm or more. Practical.
×: Dropped in less than 70,000 seconds. Bad and impractical.

<< Evaluation of curved surface adhesion >>
Each of the pressure-sensitive adhesive sheets prepared in the same manner as in the above <Evaluation of Coating Properties> was cut into a width of 20 mm × length of 22 mm, and the length direction of the sample was measured on a curved surface of a polyethylene (PE) resin cylinder having a diameter of 10 mm. It was adhered along the direction, pressed with a 2 kg rubber roller, and left for 24 hours in an atmosphere of 23 ° C. and 50%. Thereafter, the peeling state of the end portion in the length direction of the sample was visually observed, and evaluated in three steps based on the following criteria.
：: No peeling was observed, or a portion of the end of the sample less than 0.1 mm was peeled. Good Δ: The portion of 0.1 to 0.5 mm at the end of the sample was peeled off. Practical.
X: The part exceeding 0.5 mm at the end of the sample was peeled off. Bad and impractical.

<< Evaluation of constant load peelability test >>
The obtained water-based pressure-sensitive adhesive was applied on the release surface of the glassine separator so that the thickness after drying became 60 μm, and dried with hot air at 100 ° C. for 2 minutes to form a pressure-sensitive adhesive layer. Next, a polyester nonwoven fabric layer of a skin material, which is a sheet-like foam having a thickness of 10 mm and having a three-layer structure of a skin layer (fabric) / urethane foam layer / polyester nonwoven fabric layer, is adhered, and the thickness of the skin material is restored to the original value. Pressure was applied so that the thickness became 10% of the thickness, and pressure bonding was performed to prepare an adhesive sheet composed of a skin material / an adhesive layer / a release liner.
Each of the obtained pressure-sensitive adhesive sheets is cut into a width of 25 mm × length of 100 mm, the release liner is peeled off, and the exposed pressure-sensitive adhesive layer is 25 mm wide × 80 mm long at a polypropylene plate (hereinafter also referred to as “PP plate”) 23 ° C. The sample was adhered in an environment with a relative humidity of 50%, and reciprocated on a roll having a mass of 2 kg once to obtain a measurement sample.
The obtained measurement sample was allowed to stand for 24 hours in an environment of 23 ° C. and a relative humidity of 50%, and then for 1 hour in an environment of 80 ° C., and then the PP plate was placed so that the attachment surface was on the lower side. It was kept horizontal, a 100 g weight was hung on the end of the pressure-sensitive adhesive sheet where it was not stuck, left for 1 hour, and the length of the part peeled off from the PP plate was measured. When all the pieces were peeled off from the PP plate within one hour, the time up to that point was measured and evaluated in three steps based on the following criteria. The test was performed in an environment at 80 ° C. In the case of "○" or "△" evaluation, there is no problem in actual use.
：: no fall, displacement less than 20 mm. Good and practically no problem.
Δ: Dropped in 50 minutes or more. Practical.
X: Dropped in less than 50 minutes. Bad and impractical.

<< Evaluation of substrate adhesion >>
Above, the peeling liner is peeled off from each pressure-sensitive adhesive sheet created by the same method as in the <Evaluation of Constant Load Peelability Test>, and the exposed pressure-sensitive adhesive layer is rubbed with a finger, and the pressure-sensitive adhesive layer falls off from the skin material as the base material. It was evaluated in three steps based on the following criteria. In the case of "○" or "△" evaluation, there is no problem in actual use.
：: Does not fall off from the base material even when rubbed more than 15 times. Good and practically no problem.
Δ: Drops off from the substrate after 5 to 15 reciprocations. Practical.
×: The adhesive falls off in less than 5 reciprocations. Bad and impractical.

The materials used in the examples and comparative examples are shown below. In Tables 4 and 5, blanks indicate no formulation, and "-" indicates uncoated.
・ Base polymer (P)
Synthesis Examples: Acrylic aqueous dispersions (Synthesis Examples 101 to 103) obtained in each of the synthesis examples shown in Table 4, LA50: chloroprene latex [“LA-50” manufactured by Denka, NV = 50%], GFL280: chloroprene Latex [Tosoh “Skyprene Latex GFL-280”, NV = 52%]
-Tackifying resin aqueous dispersion Production example: Tackifying resin aqueous dispersion obtained in each production example shown in Table 2 (Production Examples 1 to 75)
・ Crosslinking agent (F)
ADH: 5% aqueous solution of adipic dihydrazide ・ Viscosity modifier (F)
UH420: “ADEKANOL UH-420” manufactured by Adeka, NV = 30%, ASE60: “Acrysol ASE-60” manufactured by Dow Chemical, NV = 28%
・ Antifoaming agent (F)
SN154: "SN Deformer 154" manufactured by San Nopco
・ Preservative (F)
100N: "Deltop 100N" manufactured by Osaka Gas Chemical Company
・ Water W: Ion exchange water

As described above, in Examples 1 to 23, 25 to 28, 30, 31, 36 to 47, 53, 54, 58 to 61, and 63 to 70, the aqueous adhesives of the present invention exhibited storage stability and mechanical stability. In all of the stability, coating properties, processability, peel strength, holding power, curved surface adhesiveness, constant load peeling and substrate adhesion, "△" evaluation (practical level) was 3 or less out of 10 items. All the others were evaluated as “○” (good level), indicating that they were excellent.
Further, in Examples 24, 29, 32, 33, 48 to 52, 55 to 57 and 62, the “△” evaluation (practicable level) of each evaluation was 4 to 10 out of 10 items, and “×” Since there is no evaluation (defective level), it can be used without any practical problems.
On the other hand, in Comparative Examples 1 to 19, any one of storage stability, mechanical stability, coatability, workability, peel strength, holding power, curved surface adhesiveness, constant load peeling, and substrate adhesion was used. It turns out that it is extremely inferior.

  The aqueous dispersion of the tackifier resin according to the present invention has excellent filterability even if the tackifier resin is contained at a high concentration without using an organic solvent, and has good potability, mechanical stability and storage stability. Since it can have an aqueous dispersion of a tackifying resin having a high softening point and has good compatibility with a base polymer, the aqueous adhesive containing the aqueous dispersion of the tackifier resin has excellent storage stability. Since it provides mechanical stability, coatability, workability, adhesiveness, curved surface adhesiveness, wet heat resistance, constant load peelability, substrate adhesion, etc., in the construction field (eg, exterior, interior, equipment, etc.) It can also be used in various industrial fields other than optical fields such as electric equipment (for example, home appliances, kitchen equipment, air conditioning, etc.), transport equipment (for example, ships and automobiles), furniture, and miscellaneous goods. is there.

Claims (12)

A tackifying resin (A) having a softening point of 100 to 180 ° C., and a copolymer resin (B) having an alicyclic structure and an ethylene oxide unit,
An aqueous tackifier resin dispersion containing 0.5 to 50 parts by mass of the copolymer resin (B) with respect to 100 parts by mass of the tackifier resin (A), and having an organic solvent content of 1000 ppm or less.     As the monomer units constituting the copolymer resin (B), an ethylenically unsaturated compound (b1) unit having an alicyclic structure, an ethylenically unsaturated compound (b2) unit having an ethylene oxide unit, and a carboxyl group (B3), and 10 to 30 parts by mass of the compound (b1) and 55 to 80 parts by mass of the compound (b2) in 100 parts by mass of the copolymer resin (B). And an aqueous dispersion of a tackifier resin according to claim 1, comprising 5 to 20 parts by mass of the compound (b3).   The tackifier resin aqueous dispersion according to claim 1 or 2, wherein the copolymer resin (B) has a mass average molecular weight of 1,000 to 300,000.   4. The aqueous dispersion of tackifier resin according to claim 1, wherein the copolymer resin (B) has a glass transition temperature in a range of −50 to 20 ° C. 5.   The pressure-sensitive adhesive according to any one of claims 1 to 4, wherein the tackifying resin (A) is at least one resin selected from the group consisting of a rosin-based resin, a terpene-based resin, and a petroleum-based resin. An aqueous resin dispersion.   Further, it contains a liquid resin (C) having a mass average molecular weight of 300 to 50,000 (excluding the case of the tackifying resin (A) and the copolymer resin (B)). The aqueous dispersion of a tackifier resin according to any one of claims 1 to 5.   The tackifier resin aqueous dispersion according to any one of claims 1 to 6, further comprising a surfactant (D).   The tackifier resin aqueous dispersion according to claim 7, wherein the surfactant (D) contains at least one of an anionic surfactant and a nonionic surfactant.   The tackifier resin aqueous dispersion according to any one of claims 1 to 8, further comprising a basic compound (E).   The tackifier resin aqueous dispersion according to claim 9, wherein the basic compound (E) is a tertiary amine.   An aqueous pressure-sensitive adhesive comprising: a base polymer (P); and the aqueous dispersion of a tackifier resin according to claim 1.   An adhesive sheet comprising a substrate (G) and an adhesive layer formed from the aqueous adhesive according to claim 11.