JP5348875B2 - Peelable aqueous pressure-sensitive adhesive composition, peelable pressure-sensitive adhesive, and curing pressure-sensitive adhesive sheet or tape using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a peelable aqueous adhesive composition which can be used for an adhesive tape, an adhesive sheet, an adhesive label, a surface protection film and the like, has excellent adhesiveness to various adherends, holding power, and curved surface adhesiveness, causes less change in adhesiveness along with the lapse of time, has excellent stain resistance since leaving less adhesive after peeling, and exhibits excellent storage stability, in particular, stability againt change occuring in long-term abandonment. <P>SOLUTION: The peelable aqueous adhesive composition includes (A) an emulsion obtained by emulsion polymerization of a monomer mixture (a) containing ethylenically unsaturated monomers (a1) represented by a general formula (1), and (B) a crosslinking agent. In the general formula (1): CH<SB>2</SB>=C(R<SP>1</SP>)-(R<SP>2</SP>)<SB>i</SB>-(R<SP>3</SP>)<SB>k</SB>-SO<SB>3</SB><SP>-</SP>-Y<SP>+</SP>, R<SP>1</SP>is a hydrogen atom or a methyl group, R<SP>2</SP>is an ethylene group or a -CONH- group, R<SP>3</SP>is a 1-6C alkylene group, i is 0 or 1, k is 0 or 1, i and k are not 0 together, and Y<SP>+</SP>is a hydrogen ion or a counter ion. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention can be used for applications such as pressure-sensitive adhesive tapes, pressure-sensitive adhesive sheets, pressure-sensitive adhesive labels, and surface protective films, and is excellent in adhesion to various adherends, holding power, curved surface adhesion, and changes in pressure-sensitive adhesive strength over time. Further, the present invention relates to a peelable water-based pressure-sensitive adhesive composition that is excellent in storage stability, particularly stability over time.

Conventionally, peelable pressure-sensitive adhesive compositions have been widely used for applications such as pressure-sensitive adhesive tapes, pressure-sensitive adhesive sheets, pressure-sensitive adhesive labels, and surface protective films.
In recent years, from the viewpoint of environmental hygiene, various studies have been made on water-dispersed pressure-sensitive adhesives that do not use a solvent even in a peelable pressure-sensitive adhesive composition. For example, improvement in peelability and improvement in stain resistance during peeling A) 50 to 99.9% by weight of an acrylate monomer having an alkyl group having 2 to 14 carbon atoms, b) 0.1 to 5% by weight of a carboxyl group-containing monomer, c) An aqueous dispersion copolymer of a monomer mixture consisting of 0 to 49.9% by weight of a monomer copolymerizable with component b contains a water-soluble crosslinking agent containing an oxazoline group in the copolymer. It is blended so that the oxazoline group is 0.1 to 5 equivalent per equivalent of carboxyl group, the solvent-soluble content is 40% by weight or less, the elastic modulus is ² to 50 kg / cm ² , and the re-peeling force is Re-peelable pressure-sensitive adhesive having a width of 500 g / 20 mm or less ( For example, see Patent Document 1.), a) 50 to 99.9% by weight of an acrylate monomer having an alkyl group having 2 to 14 carbon atoms, and b) 0.1 to 5% by weight of a carboxyl group-containing monomer. %) And c) a water-dispersible acrylate copolymer of a monomer mixture consisting of 0 to 49.9% by weight of a monomer copolymerizable with the above components a and b, and a crosslinking agent containing a carbodiimide group. Water dispersion in which the ratio of the carbodiimide group to the carboxyl group of the copolymer (carbodiimide group / carboxyl group) is 0.1 to 5.0 and the removability is 500 g / 20 mm width or less. A pressure sensitive adhesive for mold re-peeling (see, for example, Patent Document 2) has been proposed.

  In addition, for the purpose of improving tackiness and stain resistance, emulsion [A] obtained by emulsion polymerization of a monomer mixture having a specific composition in the presence of an anionic reactive emulsifier, crosslinking agent [B], And a re-peelable water-based pressure-sensitive adhesive composition containing a phosphoric ester compound [C] has been proposed (see, for example, Patent Documents 3 and 4).

Japanese Patent Laid-Open No. 10-114887 JP 2001-131512 A JP 2006-45411 A JP 2006-45412 A

  However, in the disclosed techniques of Patent Documents 1 and 2, the peelability is about 20 minutes at 23 ° C. after pasting in Patent Document 1 and 24 hours at 23 ° C. and 65% RH after pasting in Patent Document 2. It has releasability on the order of time, and is still not satisfied with the required performance in recent years, and further long-term releasability is required.

  Furthermore, it does not take into consideration the curved surface adhesion to the adherend having a curved surface, and further improvement is required. Further, there is little increase in adhesive strength over time, and the peeling type has excellent stain resistance and water resistance. There is a need for aqueous adhesive compositions.

  In addition, in the disclosure techniques of Patent Documents 3 and 4, the aqueous pressure-sensitive adhesive composition tends to decrease the holding power and peelability when left in an emulsion state for a long time, and is still not satisfactory. There is no need for further improvement.

  Therefore, in the present invention, under such a background, the adhesiveness to various adherends, the holding power, and the curved surface adhesiveness are excellent, the adhesive force change with time is small, and there is no adhesive residue after peeling. Peelable aqueous pressure-sensitive adhesive composition, peelable water-based pressure-sensitive adhesive composition, and curing pressure-sensitive adhesive sheet, which are excellent in soiling property and further excellent in storage stability as an aqueous pressure-sensitive adhesive composition, in particular, stability over time. The purpose is to provide a tape.

  However, as a result of intensive studies in view of such circumstances, the present inventor has obtained an ethylenic resin constituting the emulsion [A] in the peelable aqueous pressure-sensitive adhesive composition containing the emulsion [A] and the crosslinking agent [B]. By using the ethylenically unsaturated monomer (a1) represented by the general formula (1) as the unsaturated monomer component, the storage stability as an aqueous pressure-sensitive adhesive composition, in particular, adhesion such as holding power due to standing The present invention has been completed by finding that it is a pressure-sensitive adhesive composition having excellent physical properties over time.

（式中、Ｒ¹は水素原子またはメチル基であり、Ｒ²はエチレン基または−ＣＯＮＨ−基であり、Ｒ³は炭素数１〜６のアルキレン基である。ｉは０または１、ｋは０または１であ
り、ｉとｋがともに０ではない。Ｙ⁺は水素イオンまたは対イオンである。）
で示されるエチレン性不飽和単量体（ａ１）を含有する単量体混合物（ａ）を乳化重合してなるエマルジョン［Ａ］及び架橋剤［Ｂ］を含有してなる剥離型水性粘着剤組成物であり、エチレン性不飽和単量体（ａ１）が、２−アクリルアミド−２−メチル−１−プロパンスルホン酸またはその塩であり、２−アクリルアミド−２−メチル−１−プロパンスルホン酸またはその塩の含有量が、単量体混合物（ａ）全体に対して０．０１〜１０重量％であり、エマルジョン［Ａ］中のアクリル系樹脂の平均粒子径が１２０〜５００ｎｍであることを特徴とする剥離型水性粘着剤組成物に関するものである。 That is, the gist of the present invention is the general formula (1):

Wherein R ¹ is a hydrogen atom or a methyl group, R ² is an ethylene group or a —CONH— group, R ³ is an alkylene group having 1 to 6 carbon atoms, i is 0 or 1, and k is 0 or 1 and i and k are not 0. Y ⁺ is a hydrogen ion or a counter ion.)
A release-type aqueous pressure-sensitive adhesive composition comprising an emulsion [A] obtained by emulsion polymerization of a monomer mixture (a) containing an ethylenically unsaturated monomer (a1) represented by formula (A) and a crosslinking agent [B] The ethylenically unsaturated monomer (a1) is 2-acrylamido-2-methyl-1-propanesulfonic acid or a salt thereof, and 2-acrylamido-2-methyl-1-propanesulfonic acid or a salt thereof The salt content is 0.01 to 10% by weight based on the whole monomer mixture (a), and the average particle size of the acrylic resin in the emulsion [A] is 120 to 500 nm. The present invention relates to a peelable aqueous pressure-sensitive adhesive composition.

  In the present invention, a peelable pressure-sensitive adhesive obtained by crosslinking the peelable water-based pressure-sensitive adhesive composition and a pressure-sensitive adhesive layer comprising the peelable water-based pressure-sensitive adhesive composition are further laminated on a substrate. A curing pressure-sensitive adhesive sheet or tape is also provided.

  In the present invention, the term “peeling type” does not necessarily mean a one-time peeling, but also means that it is repeatedly applied and peeled off a plurality of times.

  The peelable water-based pressure-sensitive adhesive composition of the present invention is excellent in adhesiveness to various adherends, holding power, curved surface adhesiveness, has little change in adhesive strength over time, and has no adhesive residue after peeling. It has excellent contamination properties, and also has excellent effects on storage stability as an adhesive composition, particularly retention power upon standing and removability over time.

（式中、Ｒ¹は水素原子またはメチル基であり、Ｒ²はエチレン基または−ＣＯＮＨ−基であり、Ｒ³は炭素数１〜６のアルキレン基である。ｉは０または１、ｋは０または１であり、ｉとｋがともに０ではない。Ｙ⁺は水素イオンまたは対イオンである。）
で示されるエチレン性不飽和単量体（ａ１）を含有する単量体混合物（ａ）を乳化重合してなるものであり、従来公知のエチレン性不飽和単量体と配合して単量体混合物（ａ）し、好ましくは、炭素数４〜１２のアルキル基を含有する（メタ）アクリル酸アルキルエステル（ａ２）、カルボキシル基含有不飽和単量体（ａ３）、その他の不飽和単量体（ａ４）と配合して単量体混合物（ａ）とし、乳化重合してなるものである。 The present invention is described in detail below.
The emulsion [A] of the present invention is
General formula (1):

Wherein R ¹ is a hydrogen atom or a methyl group, R ² is an ethylene group or a —CONH— group, R ³ is an alkylene group having 1 to 6 carbon atoms, i is 0 or 1, and k is 0 or 1 and i and k are not 0. Y ⁺ is a hydrogen ion or a counter ion.)
The monomer mixture (a) containing the ethylenically unsaturated monomer (a1) represented by the formula (1) is obtained by emulsion polymerization, and is blended with a conventionally known ethylenically unsaturated monomer. Mixture (a), preferably (meth) acrylic acid alkyl ester (a2) containing a C 4-12 alkyl group, carboxyl group-containing unsaturated monomer (a3), other unsaturated monomer It is blended with (a4) to form a monomer mixture (a), which is obtained by emulsion polymerization.

As the ethylenically unsaturated monomer (a1) represented by the general formula (1), conventionally known monomers can be used. For example, (meth) acrylamide methanesulfonic acid (salt), (meth) acrylamide ethanesulfonic acid ( Salt), (meth) acrylamide propanesulfonic acid (salt), (meth) acrylamidomethylethanesulfonic acid (salt), (meth) acrylamide butanesulfonic acid (salt), (meth) acrylamidomethylpropanesulfonic acid (salt), ( (Meth) acrylamide dimethylethanesulfonic acid (salt), (meth) acrylamidepentanesulfonic acid (salt), (meth) acrylamide methylbutanesulfonic acid (salt), acrylamide dimethylpropanesulfonic acid (salt), acrylamide ethylpropanesulfonic acid (salt) ), Acrylamide ethyl methyl eta Compounds having a branched or straight-chain alkylene group having 1 to 6 carbon atoms such as a sulfonic acid (salt) and acrylamide propyl ethanesulfonic acid (salt) and the like, may be used singly or in combination. Among these , 2 -acrylamido-1-methylpropanesulfonic acid (salt) is required because the polymerization proceeds stably and the effect can be efficiently exhibited . .

The ethylenically unsaturated monomer (a1) represented by the general formula (1) may be an acid, a partially neutralized salt or a neutralized salt. The ionic species (Y ⁺ ) that can be used to form the neutralized salt is not particularly limited, and examples thereof include lithium ions, sodium ions, potassium ions, and ammonium ions. It may be used.

  The emulsion [A] is obtained by emulsion polymerization of a monomer mixture (a) containing the ethylenically unsaturated monomer (a1) represented by the general formula (1). A monomer mixture (a) blended with a saturated monomer, preferably a (meth) acrylic acid alkyl ester (a2) containing a C 4-12 alkyl group, a carboxyl group-containing unsaturated monomer (A3) is blended with another unsaturated monomer (a4) to form a monomer mixture (a), which is emulsion-polymerized.

  The (meth) acrylic acid alkyl ester (a2) containing an alkyl group having 4 to 12 carbon atoms is a conventionally known monomer constituting an acrylic resin, such as n-butyl (meth) acrylate, isobutyl. (Meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, nonyl (meth) ) Acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, isoundecyl (meth) acrylate, dodecyl (meth) acrylate, isododecyl (meth) acrylate . Among these n- butyl (meth) acrylate, 2-ethylhexyl acrylate, aliphatic having alkyl group of 4 to 8 carbon atoms (meth) acrylic acid alkyl ester is preferably used. These may be used alone or in combination of two or more.

Among the (meth) acrylic acid alkyl ester (a2), the carbon number of the alkyl group is the carbon number of the alkylene group of R ^{3 in} the ethylenically unsaturated monomer (a1) represented by the general formula (1). It is preferable to use the same or about 2 times.

  The carboxyl group-containing unsaturated monomer (a3) is not particularly limited and may be any conventionally known monomer. For example, (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, fumaric acid, Michael adduct of citraconic acid, glutaconic acid, itaconic acid, acrylamide N-glycolic acid, 2-acryloyloxyethyl succinic acid, cinnamic acid, (meth) acrylic acid (for example, acrylic acid dimer, methacrylic acid dimer, acrylic acid trimer Methacrylic acid trimer, acrylic acid tetramer, methacrylic acid tetramer, etc.), among which acrylic acid, methacrylic acid and the like are preferably used. These may be used alone or in combination of two or more.

  Furthermore, the other unsaturated monomer (a4) is not particularly limited and may be any conventionally known monomer, such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate. 13 or more carbon atoms such as (meth) acrylic acid alkyl ester having 1 to 3 carbon atoms such as isopropyl (meth) acrylate, tridecyl (meth) acrylate, isotridecyl (meth) acrylate, tetradecyl (meth) acrylate, etc. (Meth) acrylic acid alkyl ester having the following alkyl group, dimethylaminoethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, acrylonitrile, methacrylonite Le, styrene, alpha-methyl styrene, vinyl acetate, vinyl propionate, vinyl chloride, alkyl vinyl ether. These may be used alone or in combination of two or more.

  Further, as the unsaturated monomer (a4), in addition to the above, conventionally known functional group-containing unsaturated monomers, such as hydroxyl group-containing unsaturated monomers, epoxy group-containing unsaturated monomers, alkoxysilyl groups Containing unsaturated monomers, amide groups, methylol groups, unsaturated monomers containing carbonyl groups, polyfunctional unsaturated monomers, and the like may be used.

  Examples of the hydroxyl group-containing unsaturated monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth). Acrylate, 6-hydroxyhexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, diethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (Meth) acrylate, N-methylol (meth) acrylamide, tripropylene glycol mono (meth) acrylate, 1,4-butylene glycol mono (meth) acrylate, glycero Examples include mono (meth) acrylate, 2-hydroxyethyl acryloyl phosphate, caprolactone-modified 2-hydroxyethyl (meth) acrylate, and allyl alcohol. Among them, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) A (meth) acrylate having a hydroxyalkyl group having 1 to 4 carbon atoms such as acrylate and 4-hydroxybutyl (meth) acrylate is preferably used. These may be used alone or in combination of two or more.

  Examples of the epoxy group-containing monomer include glycidyl (meth) acrylate and allyl glycidyl ether. These may be used alone or in combination of two or more.

  Examples of the alkoxysilyl group-containing unsaturated monomer include (meth) acryloxyethyltrimethoxysilane, (meth) acryloxyethyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, and γ- (meth). Acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyldimethylmethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryl Roxypropyldimethylethoxysilane, γ- (meth) acryloxypropyltrichlorosilane, γ- (meth) acryloxypropylmethyldichlorosilane, γ- (meth) acryloxypropyldimethylchlorosilane, γ- (meth) acryloxypropyltripropio Sisilane, γ- (meth) acryloxypropylmethyldipropoxysilane, γ- (meth) acryloxypropyltributoxysilane, (meth) acryloxybutyltrimethoxysilane, (meth) acryloxypentyltrimethoxysilane, (meta ) Acryloxyhexyltrimethoxysilane, (meth) acryloxyhexyltriethoxysilane, (meth) acryloxyoctyltrimethoxysilane, (meth) acryloxydecyltrimethoxysilane, (meth) acryloxydecyltrimethoxysilane, (meth) ) Acryloxyoctadecyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinylmethyldipropo Shishiran, and the like. These may be used alone or in combination of two or more.

  Examples of unsaturated monomers containing an amide group, a methylol group, or a carbonyl group include acrylamide, methacrylamide, N-methylol acrylamide, butoxy N-methylol acrylamide, diacetone acrylamide, and 2- (acetoacetoxy) ethyl (meth). Examples thereof include acrylate and allyl acetoacetate. These may be used alone or in combination of two or more.

  Examples of the polyfunctional unsaturated monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and propylene glycol di (meth). Acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) Acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) ) Acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, glycerin methacrylate acrylate, tris (meth) acryloyloxyphosphate, glycerin di (meth) acrylate, diallyl terephthalate, tetraallyloxyethane, divinyl Examples thereof include benzene and tri (meth) allyl isocyanurate. These may be used alone or in combination of two or more.

In the present invention, the content of the ethylenically unsaturated monomer (a1) represented by the general formula (1) is 0.01 to 10% by weight with respect to the whole monomer mixture (a). In particular, it is preferably 0.05 to 5% by weight, more preferably 0.1 to 2% by weight.

  Furthermore, in the present invention, as the monomer mixture (a), the ethylenically unsaturated monomer (a1) represented by the general formula (1), the (meth) acrylic acid alkyl ester (a2), the carboxyl group-containing unsaturated monomer When the monomer (a3) and the other unsaturated monomer (a4) are contained, the content of each of the ethylenically unsaturated monomer (a1) represented by the general formula (1) is 0. 01-10 wt%, (meth) acrylic acid alkyl ester (a2) 50-99.89 wt%, carboxyl group-containing unsaturated monomer (a3) 0.1-10 wt%, other unsaturated monomers The monomer (a4) is preferably 0 to 49.89% by weight, particularly preferably 0.05 to 5% by weight of the ethylenically unsaturated monomer (a1) represented by the general formula (1) ( 55) (meth) acrylic acid alkyl ester (a2) 99.65 wt%, carboxyl group-containing unsaturated monomer (a3) is 0.3 to 5 wt%, and other unsaturated monomer (a4) is 0 to 44.65 wt%, more preferably The ethylenically unsaturated monomer (a1) represented by the general formula (1) is 0.1 to 2% by weight, the (meth) acrylic acid alkyl ester (a2) is 60 to 99.4% by weight, and the carboxyl group-containing unsaturated monomer The saturated monomer (a3) is 0.5 to 3% by weight, and the other unsaturated monomer (a4) is 0 to 39.4% by weight.

  If the content of the ethylenically unsaturated monomer (a1) represented by the general formula (1) is too low, the storage stability of the emulsion as the pressure-sensitive adhesive composition tends not to be sufficiently obtained. There is a tendency that the polymerization becomes unstable and the adhesive strength decreases. If the content ratio of the (meth) acrylic acid alkyl ester (a2) is too low, there is a tendency that sufficient adhesive strength and tack cannot be obtained. If it is too high, the amount of the carboxyl group-containing unsaturated monomer (a3) becomes small and polymerization occurs. Tends to be unstable, and the mechanical stability of the obtained emulsion tends to decrease and the peelability tends to decrease. When the content ratio of the carboxyl group-containing unsaturated monomer (a3) is too low, the polymerization becomes unstable, the mechanical stability of the obtained Em tends to decrease and the peelability tends to be insufficient. If it is too high, the viscosity of the emulsion tends to increase and handling tends to be poor, and the adhesive strength and tack tend to decrease. If the content ratio of the other unsaturated monomer (a4) is too high, the adhesive strength and tack tend to decrease.

  In the present invention, the ethylenically unsaturated monomer (a1) represented by the general formula (1), preferably (meth) acrylic acid alkyl ester (a2), carboxyl group-containing unsaturated monomer (a3) And the monomer mixture (a) containing the other unsaturated monomer (a4) is subjected to emulsion polymerization to obtain an emulsion [A]. In such emulsion polymerization, in the presence of an emulsifier It is preferable to carry out with.

The amount of the emulsifier is usually 0.1 to 15 parts by weight, particularly 0.5 to 10 parts by weight, and further 0.8 to 7 parts by weight with respect to 100 parts by weight of the monomer mixture (a). Preferably there is. When the amount of the emulsifier is too small, the polymerization tends to be unstable, and when the amount is too large, the excess emulsifier tends to increase, which tends to cause substrate adhesion and adherend contamination.
In addition, an emulsifier may be added to the emulsion monomer liquid which consists of a monomer mixture (a), may be previously added to the superposition | polymerization can, and may use both together.

As the above-mentioned emulsifier, conventionally known reactive emulsifiers or non-reactive emulsifiers can be used, but the curved surface adhesion is improved and the substrate adhesion and peelability are improved, so that the effects of the present invention are remarkable. It is particularly preferable to use a reactive emulsifier from the viewpoint of exhibiting the above.

  The amount of the reactive emulsifier used is preferably 0.5 to 10 parts by weight, more preferably 0.8 to 7 parts by weight, particularly preferably 100 parts by weight of the monomer mixture (a). 1 to 5 parts by weight. When the amount of the reactive emulsifier is too small, the polymerization tends to be unstable, and when the amount is too large, the amount of unreacted emulsifier increases, which tends to cause substrate adhesion and adherend contamination.

  Moreover, as the usage-amount of the emulsifier which does not have reactivity, the quantity of the grade which does not impair the effect of this invention can be used, Usually, 5 weight part with respect to 100 weight part of monomer mixtures (a). Hereinafter, it is particularly preferably 3 parts by weight or less.

  The reactive emulsifier is not particularly limited as long as it is a reactive emulsifier, and examples thereof include those having structures such as the following general formulas (2) to (12).

(In the general formulas (2) to (12), R ⁴ is an alkyl group, R ⁵ is a hydrogen atom or a methyl group, R ⁶ is an alkylene group, n, m, l, and o are integers of 1 or more (provided that M + 1 = 3), and X is a hydrogen atom, SO ₃ NH ₄ or SO ₃ Na.)
Examples of the alkyl group for R ⁴ include methyl group, ethyl group, propyl group, butyl group, amyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, Examples thereof include alkyl groups having 1 to 20 carbon atoms such as a pentadecyl group, a cetyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, and an aralkyl group.
Examples of the alkylene group for R ⁶ include a methylene group, an ethylene group, a propylene group, a butylene group, an amylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, a dodecylene group, a tridecylene group, a tetradecylene group, C1-C20 alkylene groups, such as a pentadecylene group, a acetylene group, a heptadecylene group, an octadecylene group, a nonadecylene group, an araalkylene group, can be mentioned.

  Examples of the reactive emulsifier include conventionally known emulsifiers. Specifically, Adeka Soap SE-10N (anionic), Adeka Soap SE-20N (anionic), Adeka Soap SR-10 (anionic) ), ADEKA rear soap SR-20 (anionic), ADEKA rear soap NE-10 (nonionic), ADEKA rear soap NE-20 (nonionic), ADEKA rear soap NE-30 (nonionic), ADEKA rear soap NE -40 (nonionic), ADEKA rear soap ER-10 (nonionic), ADEKA rear soap ER-20 (nonionic), ADEKA rear soap ER-30 (nonionic), ADEKA rear soap ER-40 (nonionic) , ADEKA rear soap SDX-730 (anionic), ADEKA rear soap SDX-731 (anionic), Ade Rear soap PP-70 (anionic), Adequaria soap PP-710 (anionic) (above, manufactured by Asahi Denka Co., Ltd.); Eleminol JS-2 (anionic), Eleminol JS-20 (anionic), Eleminol RS -30 (anionic) (above, manufactured by Sanyo Chemical Co., Ltd.); Latemul S-180A (anionic), Laterum S-180 (anionic), Lateml PD-104 (anionic) (above, Kao Corporation) Aquaron BC-05 (anionic), Aqualon BC-10 (anionic), Aqualon BC-20 (anionic), Aqualon HS-05 (anionic), Aqualon HS-10 (anionic), Aqualon HS -20 (anionic), Aqualon RN-10 (nonionic), Aqualon RN-20 (nonionic), Aqua RN-30 (nonionic), Aqualon RN-50 (nonionic), Aqualon KH-05 (anionic), Aqualon KH-10 (anionic), New Frontier S-510 (anionic) Kogyo Seiyaku Co., Ltd.); Phosfinol TX (anionic) (manufactured by Toho Chemical Industry Co., Ltd.).

  Among the above emulsifiers, it is particularly preferable to use an anionic emulsifier from the viewpoint of stability during polymerization and adhesion to a substrate, and further neutralized with a monovalent metal salt (for example, sodium salt, potassium salt, etc.). The use of an emulsifier that does not contain an ethylene oxide chain in the structure, specifically, “Eleminol JS-2”, “Eleminol JS-20”, “Latemul S-180”, etc. is excellent in curved surface adhesion. And it is most preferable in that the adhesive force change with time is small.

  As the emulsifier having no reactivity, conventionally known emulsifiers can be used, for example, anionic emulsifiers such as alkyl or alkylallyl sulfate, alkyl or alkylallyl sulfonate, dialkyl sulfosuccinate, alkyltrimethylammonium chloride, Cationic emulsifiers such as alkylbenzyl ammonium chloride, and nonionic emulsifiers such as polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, and polyoxyethylene carboxylic acid ester.

  Specific examples of the non-reactive emulsifier include anionic types such as sodium dodecylbenzene sulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium alkyl sulfonate, and the like. Nonionic types include, for example, polyoxyethylene. Examples include alkyl type, polyoxyethylene alkyl ether type, polyoxyethylene glycol type, and polyoxyethylene propylene glycol type.

  In conducting emulsion polymerization, it is preferable to use a polymerization initiator, and examples of such polymerization initiator include those conventionally used for emulsion polymerization, for example, water-soluble or oil-soluble ones are used. Is possible. Specifically, alkyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, p-methane hydroperoxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, t -Butylcumyl peroxide, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, di-isobutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, t-butylperoxyisobutylene Organic peroxides such as 2,2′-azobisisobutyronitrile, dimethyl-2,2′-azobisisobutyrate, 2,2′-azobis (2,4-dimethylvaleronitrile), 2, 2′-azobis (2-methylbutyronitrile), potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, ammonium (amine) salt of 4,4′-azobis-4-cyanovaleric acid, 2, 2'-azobis (2-methylamidooxime) dihydrochloride, 2,2'-azobis (2-methylbutanamidooxime) dihydrochloride tetrahydrate, 2,2'-azobis {2-methyl-N- [1, 1-bis (hydroxymethyl) -2-hydroxyethyl] -propionamide}, 2,2′-azobis [2-methyl-N- (2-hydroxy) Ethyl) -propionamide], various redox catalysts (in this case, as an oxidizing agent, ammonium persulfate, potassium persulfate, sodium persulfate, hydrogen peroxide, t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, p-methane hydroperoxide and the like include sodium sulfite, acidic sodium sulfite, Rongalite, ascorbic acid and the like as the reducing agent.) Among these, water-soluble polymerization is preferred because of excellent polymerization stability. Initiators are preferred, for example, potassium persulfate, ammonium persulfate, sodium persulfate, redox catalyst (oxidizer: potassium persulfate, ammonium persulfate, sodium persulfate, reducing agent: sodium sulfite, acidic sodium sulfite, Rongalite, ascorb Binic acid) and the like are preferred.

  The amount of the polymerization initiator used may be a general amount that can be used for emulsion polymerization, and is usually 0.01 to 5 parts by weight, and further 0 to 100 parts by weight of the monomer mixture (a). The amount is preferably 0.03 to 3 parts by weight. If the amount is too small, the polymerization rate tends to be slow. If the amount is too large, the peelability tends to decrease.

  The polymerization initiator may be added in advance to the polymerization can, may be added immediately before the start of polymerization, or may be added during the polymerization as necessary. Moreover, you may add to the monomer mixture (a) of (a1)-(a4) previously, or may add to the emulsion liquid which consists of this monomer mixture (a). In addition, the polymerization initiator may be separately dissolved in a solvent or the above monomer and added, or the dissolved polymerization initiator may be further added in an emulsified form.

  Further, if necessary, a pH buffering agent may be used in combination for pH adjustment at the time of polymerization, and the amount of the pH buffering agent is usually 0.1% relative to 100 parts by weight of the monomer mixture (a). It is preferable that it is 01-10 weight part, especially 0.1-3 weight part.

  The pH buffering agent is not particularly limited as long as it has a pH buffering action. Specifically, sodium bicarbonate, potassium bicarbonate, monosodium phosphate, monopotassium phosphate, disodium phosphate, phosphorus Examples thereof include trisodium acid, sodium acetate, ammonium acetate, sodium formate, and ammonium formate.

  The amount of water used is preferably 20 to 400 parts by weight, more preferably 25 to 200 parts by weight, and particularly preferably 30 to 150 parts by weight with respect to 100 parts by weight of the monomer mixture (a). . If the amount of water used is too small, the resulting resin composition tends to have a high viscosity, and the polymerization stability tends to decrease. If too much water is used, the resulting resin composition has a low concentration and becomes a film. There is a tendency for the drying property to decrease.

The monomer mixture (a) of (a1) to (a4) is polymerized with the initiator in the presence of an emulsifier, preferably a reactive emulsifier.
(1) Charge the whole amount of monomer mixture (a), emulsifier, water, etc., and polymerize by heating.
(2) Charge water, an emulsifier and a part of the monomer mixture (a) into the reaction can, polymerize by heating, and then continue the polymerization by dropping or dividing the remaining monomer mixture (a). ,
(3) Water, an emulsifier, etc. are charged into the reaction can and heated up, and then the monomer mixture (a) is dropped or added in portions for polymerization.
However, the methods (2) and (3) are preferable because the polymerization temperature can be easily controlled.

The polymerization conditions in the above polymerization method are those generally used conventionally. For example, the following conditions can be adopted.
In the method (1), a temperature range of about 40 to 100 ° C. is appropriate, and the reaction is carried out for about 1 to 8 hours after the start of temperature increase.
In the method (2), 1 to 50% by weight of the monomer mixture (a) is polymerized at 40 to 90 ° C. for 0.1 to 4 hours, and the remaining monomer mixture (a) is then used for 1 to 5 hours. It is dropped or added in portions over a certain degree, and then ripened for about 1 to 3 hours at the same temperature.
In the method (3), water is charged into a polymerization can, the temperature is raised to 40 to 90 ° C., and the monomer mixture (a) is dropped or dividedly added over about 2 to 5 hours. Aged for about 3 hours.

  In the above polymerization method, the monomer mixture (a) is prepared by dissolving an emulsifier (or a part of the emulsifier) in the monomer mixture (a) or preliminarily in the state of an O / W type emulsion. It is preferable to place it in terms of polymerization stability.

  The method for adjusting the emulsified liquid is not particularly limited, but the above-described (a1) to (a4) are prepared after dissolving the emulsifier in water, and the mixed liquid is stirred and emulsified, or the emulsifier is dissolved in water and then stirred. However, the method etc. which prepare said (a1)-(a4) are mentioned.

Agitation at the time of emulsification of the emulsion can be carried out using a stirring device in which the components are mixed and a stirring blade such as a homodisper or paddle blade is attached.
There is no problem as long as the temperature during emulsification is such that the mixture does not react during emulsification, and usually about 5 to 60 ° C. is appropriate.

Further, the average particle size of the acrylic resin in the obtained emulsion [A] is preferable in terms of adhesion to the substrate and water resistance , which are required to be fine particles of 120 to 500 nm.

  Furthermore, the solid content concentration of the emulsion [A] is preferably 10 to 70% by weight, particularly 20 to 65% by weight, and more preferably 40 to 60% by weight from the viewpoint of drying property and coating property. The glass transition temperature of the acrylic resin in [A] is −30 to −70 ° C., particularly −45 to −65 ° C., and further −50 to −60 ° C. It is preferable in terms of the balance of curved surface adhesion.

  Next, the crosslinking agent [B] used in the present invention may be any one that crosslinks the resin in the emulsion [A] with a conventionally known crosslinking agent. For example, an oxazoline compound (b1), a carbodiimide compound (B2), metal compound (b3), epoxy compound (b4), aziridine compound (b5), isocyanate compound (b6), melamine compound (b7), hydrazine compound (b8), amine compound ( b9) etc. can be used.

Among these, an aqueous type crosslinking agent is preferable in terms of excellent liquid stability after blending the crosslinking agent, and in particular, an oxazoline compound (b1), a carbodiimide compound (b2), a metal compound (b3), and an epoxy compound. (B4) and a hydrazine compound (b8) are preferred.
These crosslinking agents [B] can be used alone or in combination of two or more.

  Examples of the oxazoline-based compound (b1) include addition polymerizable 2-oxazolines (for example, 2-isopropenyl-2-oxazoline) having a substituent having an unsaturated carbon-carbon bond at the 2-position carbon position and other non-polymerizable compounds. Examples include commercially available products such as copolymers with saturated monomers, “Epocross WS-500”, “Epocross WS-700”, “Epocross K-2010E”, and “Epocross K-2020E” manufactured by Nippon Shokubai Co., Ltd. , “Epocross K-2030E” and the like.

  As the carbodiimide compound (b2), any compound having at least two carbodiimide groups may be used. For example, “Carbodilite V-02”, “Carbodilite V-02-L2”, “Carbodilite V-04” manufactured by Nisshinbo Co., Ltd. ”,“ Carbodilite V-06 ”,“ Carbodilite E-01 ”,“ Carbodilite E-02 ”, and the like.

Examples of the metal compound (b3) include metal alkoxides such as tetraethyl titanate, tetraethyl zirconate, and aluminum isopropionate, aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, Examples include acetylacetone and acetoacetate of polyvalent metals such as zirconium, metal chelate compounds of ethylenediaminetetraacetic acid coordination compounds, acetic acid-ammonium complex salts, ammonium-carbonate complex salts, and the like. Of these, the aqueous type is preferred.

  Examples of the epoxy compound (b4) include bisphenol A / epichlorohydrin type epoxy resin and sorbitol polyglycidyl ether (for example, “Denacol EX-611”, “Denacol EX-612”, “Denacol EX” manufactured by Nagase ChemteX Corporation). -614 "," Denacol EX-614B "," Denacol EX-622 ", etc.), polyglycerol polyglycidyl ether (for example," Denacol EX-512 "," Denacol EX-521 "manufactured by Nagase ChemteX Corporation), Pentaerythritol polyglycidyl ether (for example, “Denacol EX-411” manufactured by Nagase ChemteX), diglycerol polyglycidyl ether (for example, “Denacol EX-421” manufactured by Nagase ChemteX), glycerol Glycidyl ether (for example, “Denacol EX-313”, “Denacol EX-314” manufactured by Nagase ChemteX), etc.), trimethylolpropane polyglycidyl ether (for example, “Denacol EX-321” manufactured by Nagase ChemteX) Resorcinol diglycidyl ether (for example, “Denacol EX-201” manufactured by Nagase ChemteX), neopentyl glycol diglycidyl ether (for example, “Denacol EX-211” manufactured by Nagase ChemteX), 1,6 -Hexanediol diglycidyl ether (for example, “Denacol EX-212” manufactured by Nagase ChemteX Corporation), hydrogenated bisphenol A diglycidyl ether (for example, “Denacol EX-252” manufactured by Nagase ChemteX Corporation) , D Renglycol diglycidyl ether (for example, “Denacol EX-810”, “Denacol EX-811”, etc. manufactured by Nagase ChemteX), etc.), diethylene glycol diglycidyl ether (eg, “Denacol EX-850”, manufactured by Nagase ChemteX, "Denacol EX-851" etc.), polyethylene glycol diglycidyl ether (for example, "Denacol EX-821", "Denacol EX-830", "Denacol EX-832", "Denacol EX-841" manufactured by Nagase ChemteX Corporation) , “Denacol EX-861”, etc.), propylene glycol diglycidyl ether (eg, “Denacol EX-911” etc., manufactured by Nagase ChemteX), polypropylene glycol diglycidyl ether (eg, manufactured by Nagase ChemteX) "Denacol EX-941", "Denacol EX-920", "Denacol EX-931", etc. are mentioned. Among these, an aqueous type is preferable.

  The aziridine compound (b5) may be any compound containing at least two aziridine groups, and examples thereof include “Chemite DZ-33” and “Chemite DZ-22E” (manufactured by Nippon Shokubai Co., Ltd.).

  Examples of the isocyanate compound (b6) include toluylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, metaxylylene diisocyanate, 1,5-naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenation. Isocyanate compounds such as toluylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, tetramethylxylene diisocyanate, burette polyisocyanate compounds such as “Sumijour N” (manufactured by Sumitomo Bayer Urethane Co., Ltd.), “Desmodur IL”, “Death” Isocyanurate such as “Module HL” (manufactured by Bayer AG), “Coronate EH” (manufactured by Nippon Urethane Co., Ltd.) A polyisocyanate compound having a ring, an adduct polyisocyanate compound such as “Sumijour L” (manufactured by Sumitomo Bayer Urethane Co., Ltd.), an adduct polyisocyanate compound such as “Coronate HL” (manufactured by Nippon Polyurethane Co., Ltd.), “Aquanate 100”, “ Examples thereof include self-emulsifying water-dispersed polyisocyanate compounds such as “Aquanate 110”, “Aquanate 200”, and “Aquanate 210” (manufactured by Nippon Polyurethane Co., Ltd.). Among these, a water dispersion type is preferable. A blocked isocyanate may also be used.

  Examples of the melamine compound (b7) include hexamethoxymethylol melamine and methoxymethylol urea.

The hydrazine-based compound (b8) may be any compound having at least two or more hydrazide groups in the molecule. For example, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid Dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, 1,3-bis (hydrazinocarbonoethyl) -5-isopropylhydrantoin, 7,11-octadecadien-1,18-dicarbohydrazide, etc. It is done.

  Examples of the amine compound (b9) include 1,3-diaminopropane, bis- (3-aminopropyl) ether, 1,2-bis- (3-aminopropoxy) ethane, 1,3-bis- (3-amino Propoxy) -2,2-dimethylpropane, 1,4-diaminobutane and the like.

The content of the cross-linking agent [B] depends on the type of the cross-linking agent, but the cross-linking agent per 1 equivalent of functional groups that contribute to cross-linking such as carboxyl groups contained in the acrylic resin in the emulsion [A]. It is preferable that the reactive group contained in is a ratio of 0.001 to 1 equivalent, particularly 0.003 to 0.7 equivalent, and further 0.005 to 0.5 equivalent. preferable. If the content is too small, crosslinking of the acrylic resin becomes insufficient, and the holding power and peelability tend to be poor. If the content is too large, the adhesive strength, tack, and curved surface adhesion tend to decrease.
The content of the crosslinking agent [B] is usually preferably 0.01 to 5 parts by weight, particularly 0.1 to 5 parts by weight with respect to 100 parts by weight of the solid content of the emulsion [A]. Furthermore, it is preferably 0.1 to 1 part by weight.

  Thus, a peelable water-based pressure-sensitive adhesive composition containing the emulsion [A] and the crosslinking agent [B] of the present invention is obtained. In the present invention, however, it may further contain a phosphate ester compound [C]. It is preferable from the viewpoint of improving peelability.

  As the phosphoric ester compound [C], conventionally known compounds can be used, for example, sesquioctyl phosphate, tributyl phosphate, trioctyl phosphate, tris (β-chloroethyl) phosphate, tris (β-chloropropyl) phosphate, Tris (dichloropropyl) phosphate, triphenyl phosphate, tricresyl phosphate, tris (i-properphenyl) phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, tributoxyethyl phosphate, alkylpolyoxyethylene phosphate, alkylphenol poly Examples thereof include oxyethylene phosphate esters and neutralized salts thereof such as sodium, potassium, ammonia and amines. A neutralized amine salt is preferred in that it has excellent water resistance. These phosphate ester compounds [C] can be used alone or in combination of two or more.

  The content of the phosphoric ester compound [C] is preferably 0.01 to 5 parts by weight, particularly 0.03 to 1 part by weight with respect to 100 parts by weight of the solid content of the emulsion [A]. Further, it is preferably 0.05 to 0.5 parts by weight, particularly preferably 0.1 to 0.5 parts by weight. If the amount of the phosphoric ester compound [C] is too small, the peelability tends to be poor, and if it is too large, the curved surface adhesiveness and water-resistant adhesiveness tend to decrease.

  In the present invention, the emulsion [A] obtained above and a crosslinking agent [B], preferably a phosphoric acid ester compound [C], can also be used to form a pressure-sensitive adhesive composition. Polypropylene) It is preferable to further contain a tackifier resin [D] from the viewpoint that adhesion to an adherend and curved surface adhesion can be improved.

  As the tackifying resin [D], conventionally known ones can be used. For example, modified rosins such as maleated rosin, fumarinated rosin, acrylated rosin, disproportionation, dimerization, hydrogenation, etc. Rosin, rosin resins such as those obtained by esterification of rosin with glycerin or pentaerythritol, xylene resin, terpene resin, terpene phenol resin, petroleum resin, coumarone indene resin, styrene resin, ethylene / vinyl acetate resin, etc. Furthermore, when these tackifying resins [D] are added, it is preferable to blend those tackifying resins [D] previously emulsified.

  Examples of the emulsion include Superester E-720, Superester E-730-55, Superester E-625, Superester E-650, Superester E-865, Superester E-865NT, Superester NS -100H, superester NS-120A, superester NS-125A, tamanol E-100, tamanor E-200NT, emulsion AM-1002, emulsion SE-50 (above, manufactured by Arakawa Chemical Co., Ltd.); Harlister SK-508, Harlister SK-70D, Harlister SK-822E, Harlister SK-816E, Harlister SK-532D, Harlister SK-508H, Harlister SK-90D-55, Harlister SK-501, Harlister SK-218N , Harlister SK-370N, Harlister SK-385NS, Harlister SK-501NS (above, manufactured by Harima Chemicals Co., Ltd.); Nanolet N-1250, Nanolet N-1050 (manufactured by Yasuhara Chemical Co., Ltd.), and ethylene / vinyl acetate resin SUMIKAFLEX 205HQ, SUMIKAFLEX 305HQ, SUMIKAFLEX 401HQ, SUMIKAFLEX 510HQ (manufactured by Sumitomo Chemical Co., Ltd.) and the like can be used.

  The content of the tackifier resin [D] is usually 1 to 30 parts by weight, particularly 3 to 25 parts by weight as the solids of the tackifier resin [D] with respect to 100 parts by weight of the solids of the emulsion [A]. Part, more preferably 5 to 20 parts by weight, especially 5 to 10 parts by weight. If the amount is too small, the effect on the adhesion to the olefin adherend and the curved surface adhesion tends to be insufficient. If it is too much, the peelability tends to be poor or the tack tends to decrease.

  Furthermore, in the present invention, a plasticizer (for example, liquid polybutene, mineral oil, lanolin, liquid polyisoprene and liquid polyacrylate, etc.), antiseptic / antifungal agent, rust inhibitor, antifreezing agent, high boiling point solvent, pigment as necessary , Colorants, fillers (zinc white, titanium white, calcium carbonate, clay, etc.), metal powders, antifoaming agents, thickeners, wetting agents, adhesion modifiers, UV absorbers, hindered amine light stabilizers, etc. A weather resistance imparting agent, an antioxidant and the like can be added as appropriate, or can be added before or during polymerization of the emulsion polymerization.

Thus, the peelable water-based pressure-sensitive adhesive composition of the present invention can be obtained. Such a peelable water-based pressure-sensitive adhesive composition is usually provided as a pressure-sensitive adhesive layer on a substrate sheet or the like and is practically used as a pressure-sensitive adhesive sheet or a pressure-sensitive adhesive tape. In order to produce such a pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape, the base material on which the release-type water-based pressure-sensitive adhesive composition of the present invention is first adjusted to an appropriate concentration and subjected to silicon treatment, etc. The pressure-sensitive adhesive layer can be formed by coating on the treated surface or directly on the substrate and drying by, for example, heat treatment at 80 to 120 ° C. for 5 seconds to 10 minutes.
Alternatively, the release-type aqueous pressure-sensitive adhesive composition can be applied to a release paper or release film and dried, and then transferred onto a substrate.

  Examples of such base materials include polyvinyl chloride, polyvinylidene chloride, polybutene, polybutadiene, polyurethane, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polyethylene, polypropylene, ethylene-propylene copolymer, polymethylpentene, and polybutylene. Examples thereof include films such as terephthalate, metal foil, and porous materials such as paper and nonwoven fabric.

In addition, the peelable water-based pressure-sensitive adhesive composition of the present invention exhibits a particularly excellent effect when used as a pressure-sensitive adhesive sheet or tape pressure-sensitive adhesive. It is required to have the ability to cut by hand without using tools such as scissors and a cutter. In this case, as a base material, a cross sheet in which a flat yarn formed by cutting and stretching an olefin-based resin film is interwoven, and a cross-sheet in which a laminate layer of the same resin is provided on at least one surface, or an olefin-based resin It is preferable to use an embossed film provided with a number of grooves in the width direction of the film.

When the olefin resin film is used as a substrate, it is preferable to perform a surface treatment such as high-pressure corona discharge on the surface on which the pressure-sensitive adhesive is to be applied in order to improve the substrate adhesion of the pressure-sensitive adhesive.

  The thickness of the substrate is usually preferably 10 to 300 μm, and particularly preferably 20 to 200 μm. A layer made of the above-described peelable water-based pressure-sensitive adhesive composition is formed on one or both sides of the substrate in an amount of 1 to 100 μm, and further 3 It is provided in a thickness of ˜70 μm, particularly 5 to 50 μm, and forms such as a sheet shape or a tape shape.

  The peelable water-based pressure-sensitive adhesive composition of the present invention is for temporary surface protection or temporary adhesion for preventing scratches or contamination during transport, processing, cutting, etc. of metal plates, glass plates, plastic plates, etc. It is very useful as a pressure-sensitive adhesive tape or sheet, or as a pressure-sensitive adhesive for release labels, and particularly as a pressure-sensitive adhesive sheet or tape for curing used in painting, interior decoration, building materials, and the like.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded.
In the examples, “parts” and “%” mean weight basis unless otherwise specified.

Example 1
Sodium 2-acrylamido-2-methylpropanesulfonate (ATBS-Na) (a1) 0.2 part, 2-ethylhexyl acrylate (a2) 67.5 parts, n-butyl acrylate (a2) 20.0 parts, acrylic acid (A3) 1.0 part, 11.3 parts of methyl methacrylate (a4), 0.075 part of 1-dodecanethiol as a chain transfer agent, an anionic reactive emulsifier (manufactured by Sanyo Chemical Industries, “Eleminol JS-20”: active ingredient 38%, the structure of the above general formula (4), R _1: an alkyl group, X: SO ₃ Na) 3.16 parts of a second 0.5 parts sodium phosphate as a pH buffer, water 37.6 Parts were mixed and stirred to obtain an emulsion composed of the monomer mixture (a).

  Next, a nonionic emulsifier (manufactured by Nippon Emulsifier Co., Ltd., “RAA-12904: active ingredient 100%” 0.08 part, 35.3 parts of water, and 35.3 parts of water were charged into a flask equipped with a cooling tube and a stirring blade. 5% (7.1 parts) of the above emulsion was added, 1.7 parts of 3% aqueous potassium persulfate solution was added, emulsion polymerization was performed, and 15 minutes later, A mixture of the remaining 95% (134.3 parts) and 2.6 parts of a 3% aqueous potassium persulfate solution was added dropwise over 3.5 hours at 80 ° C. After completion of the addition, the mixture was maintained at 80 ° C. for 2 hours. After stirring, the mixture was cooled to 60 ° C. and neutralized by adding 1.5 parts of a 10% aqueous ammonia solution, then cooled to 55 ° C., and tertiary butyl hydroperoxide (manufactured by NOF Corporation, “Perbutyl H -69 ") 10% aqueous solution 0.5 part and 5 After adding 1.0 part of sodium hydrogen sulfite aqueous solution and reacting for 15 minutes, 0.5 part of 10% aqueous solution of tertiary butyl hydroperoxide (Nippon Yushi Co., Ltd., “Perbutyl H-69”) 1.0 part of 5% aqueous sodium hydrogen sulfite solution was added and reacted for 15 minutes, then cooled to 30 ° C., adjusted to pH 8.5 with 10% aqueous ammonia solution, Filtration through a wire mesh gave emulsion [A] (solid content: 55.0%, viscosity: 1500 mPa · s (B-type viscometer, 23 ° C., 60 rpm), average particle size: 200 nm, glass transition temperature: −54. ° C).

Further, the following blending was performed on the obtained emulsion [A].
0.5 parts of carbodiimide compound (b2) “Carbodilite V-04 (manufactured by Nisshinbo Co., Ltd.)” as a crosslinking agent [B] is added to 100 parts of the solid content of the emulsion [A] (0.2 parts as an active ingredient). ), 0.9 part (0.045 parts as an active ingredient) of a 5% aqueous solution of metal compound (b3) (zinc ammonium acetate [Zn (NH ₃ ) ₄ (CH ₃ COO) ₂ ]), phosphate ester compound [C] “ES-N” (Kitahiro Chemical Co., Ltd.) 0.25 part, and tackifier resin [D] “Tamanol E-100” (Arakawa Chemical Co., solid content: 53%) 18.9 parts (10 parts as solid content), 0.02 part of “SN deformer 777” (manufactured by San Nopco) as an antifoaming agent, and finally “Adecanol UH-541VF” as a thickener, and a viscosity of 2000 mPa · s (B-type viscosity Meter, 23 ° C., adjusted to 60 rpm), to obtain a releasable aqueous pressure-sensitive adhesive composition of the present invention.
About the obtained peeling type water-based adhesive composition, the adhesive sheet was produced as follows and the following evaluation was performed.

[Preparation of adhesive sheet]
The obtained peelable water-based pressure-sensitive adhesive composition was applied onto a corona-treated surface of a polyethylene resin cloth sheet (Diatex Co., Ltd., thickness 120 μm) so that the thickness after drying was 40 μm. After drying for a minute, the untreated surface (back surface) of the cloth sheet was bonded together, and then treated at 40 ° C. for 3 days to complete the cross-linking, thereby producing an adhesive sheet.

<Initial adhesive strength>
30 minutes after bonding the obtained adhesive sheet to a SUS304 polishing plate at 23 ° C. and 50% RH by reciprocating two 2 kg rollers, it was peeled 180 degrees according to the method for measuring the adhesive strength of JIS Z 0237 The strength (N / 25 mm) was measured.

<Curved surface adhesion>
After sticking a 25 mm wide and 40 mm long adhesive sheet piece to a curing sheet (polyethylene laminate sheet) with a 2 kg roller, wrap it around a curved surface of a 25 mmφ iron cylinder and leave it for 72 hours (40 ° C.), then peel off Was evaluated by the length (mm) in the long side direction.

<Retention force>
The obtained adhesive sheet was affixed to a stainless steel plate so that the area was 25 mm × 25 mm, applied with a load of 1 kg under the condition of 40 ° C., and according to the holding power measurement method of JIS Z 0237, The deviation (mm) or drop time (min) after 24 hours was measured.

<Ball tack>
In the obtained pressure-sensitive adhesive sheet, J.P. Using a dow ball tack measuring machine, the ball number of the maximum diameter that stops on the test piece (adhesive surface) was measured at a test piece of 25 mm × 100 mm and an angle of 30 ° under the condition of 23 ° C. × 50% RH. .

<Peelability>
(1) Adhesive force obtained after aging, (i) SUS304 polishing plate, (ii) floor material <named wood high-quality color floor-MKF-1232M4 medium oak (manufactured by Senye)>, and (iii) salt After attaching a 2 kg roller by reciprocating a 2 kg roller at 23 ° C. and 50% RH, and then (a) leaving it at 40 ° C. for 7 days, b) About 180 degree peel strength (N / 25mm) was measured according to the measuring method of the adhesive force of JISZ0237 about after leaving it for 2 days in warm water of 40 degreeC.

(2) Contamination resistance after elapse of time After the adhesive strength after (a) leaving at 40 ° C. for 7 days and (b) leaving at 40 ° C. warm water for 2 days is measured, The degree of contamination was visually observed, and the contamination resistance was evaluated as follows.
○ ··· Contamination was not observed △ ··· Attached marks were observed × 1 ······ Remaining adhesive was observed (peeling at the substrate interface)
× 2: Adhesive residue was observed (adhesive cohesive failure)

<Storage stability of pressure-sensitive adhesive composition>
After the pressure-sensitive adhesive composition after blending each component was allowed to stand at 23 ° C. for 3 months, a pressure-sensitive adhesive sheet was prepared in the same manner as described above, and each physical property was evaluated in the same manner as described above.

Examples 2-10, Comparative Examples 1-2
Except having changed into a composition as shown in Table 1 and Table 2, it carried out similarly to Example 1 and obtained emulsion [A]. Furthermore, as shown in Table 1 and Table 2, the obtained emulsion [A] was the same as Example 1 except that a crosslinking agent [B], a phosphate ester compound [C], and a tackifier resin [D] were added. Then, a peelable water-based pressure-sensitive adhesive composition was obtained. A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 for the obtained peelable water-based pressure-sensitive adhesive composition, and the same evaluation as in Example 1 was performed.
The evaluation results of Examples and Comparative Examples are shown in Tables 3 to 6.

In addition, the numerical value of a monomer mixture, a chain transfer agent, an emulsifier, a pH buffer agent, water, a crosslinking agent, a phosphate ester compound, and a tackifying resin in the table indicates a blending amount (part).
The materials shown in the table are as shown below.

(Monomer)
MMA: methyl methacrylate BA: n-butyl acrylate 2-EHA: 2-ethylhexyl acrylate AA: acrylic acid DAAM: diacetone acrylamide TBAS-Q: 2-acrylamido-2-methylpropanesulfonic acid ATBS-Na: 2-acrylamide- Sodium 2-methylpropanesulfonate

(emulsifier)
JS-20: “Eleminol JS-20” (active ingredient 38%) manufactured by Sanyo Chemical Industries
PD-104: “Latemul PD-104” manufactured by Kao Corporation (active ingredient 20%)
RAA-12904: “RAA-11902” (100% active ingredient) manufactured by Nippon Emulsifier Co., Ltd. (nonionic emulsifier having no reactive group)

(Crosslinking agent)
V-04: “Carbodilite V-04” manufactured by Nisshinbo Co., Ltd. (active ingredient 40%)
WS700: “Epocross WS-700” (25% active ingredient) manufactured by Nippon Shokubai Co., Ltd.
Metal compound: zinc ammonium acetate [Zn (NH ₃ ) ₄ (CH ₃ COO) ₂ ] 5% aqueous solution EX313: “Denacol EX-313” (100% active ingredient) manufactured by Nagase ChemteX Corporation
ADH: “Adipic acid dihydrazide” manufactured by Otsuka Chemical Co., Ltd. (added as 5% aqueous solution)

(Phosphate ester compounds)
ES-N: “ES-N” (100% active ingredient) manufactured by Kitahiro Chemical Co., Ltd.

(Tackifying resin)
E-100: “Tamanol E-100” manufactured by Arakawa Chemical Co., Ltd. (solid content: 53%)

  The peelable water-based pressure-sensitive adhesive composition of the present invention is excellent in adhesiveness to various adherends, holding power, curved surface adhesiveness, has little change in adhesive strength over time, and has no adhesive residue after peeling. Excellent contamination, and also has excellent storage stability, especially excellent stability over time, and prevents scratches during transportation, processing, cutting, etc. of metal plates, glass plates, plastic plates, etc. Adhesive tape or sheet for temporary surface protection or temporary adhesion to prevent contamination, etc., especially for coating, interior, building materials, etc. It is very useful as an adhesive.

Claims (7)

General formula (1):

Wherein R ¹ is a hydrogen atom or a methyl group, R ² is an ethylene group or a —CONH— group, R ³ is an alkylene group having 1 to 6 carbon atoms, i is 0 or 1, and k is 0 or 1 and i and k are not 0. Y ⁺ is a hydrogen ion or a counter ion.)
A release-type aqueous pressure-sensitive adhesive composition comprising an emulsion [A] obtained by emulsion polymerization of a monomer mixture (a) containing an ethylenically unsaturated monomer (a1) represented by formula (A) and a crosslinking agent [B] Is a thing,
The ethylenically unsaturated monomer (a1) is 2-acrylamido-2-methyl-1-propanesulfonic acid or a salt thereof;
The content of 2-acrylamido-2-methyl-1-propanesulfonic acid or a salt thereof is 0.01 to 10% by weight based on the whole monomer mixture (a),
The peelable water-based pressure-sensitive adhesive composition, wherein an average particle size of the acrylic resin in the emulsion [A] is 120 to 500 nm . The monomer mixture (a) is an ethylenically unsaturated monomer (a1) represented by the general formula (1) (0.01) to 10% by weight, and a (meth) acryl containing an alkyl group having 4 to 12 carbon atoms. Acid alkyl ester (a2) 50 to 99.89% by weight, carboxyl group-containing unsaturated monomer (a3) 0.1 to 10% by weight, other unsaturated monomer (a4) 0 to 49.89% by weight releasable aqueous pressure-sensitive adhesive composition according to claim 1 Symbol placement, characterized by containing a. The peelable aqueous pressure-sensitive adhesive composition according to claim 1 or 2 , wherein the emulsion [A] is an emulsion obtained by emulsion polymerization of the monomer mixture (a) using a reactive emulsifier. Furthermore, the release type water-based pressure-sensitive adhesive composition according to any one of claims 1 to 3 , further comprising a phosphate ester compound [C]. Furthermore, tackifying resin [D] is contained, The peelable water-based adhesive composition in any one of Claims 1-4 characterized by the above-mentioned. Peelable adhesive agent releasable aqueous pressure-sensitive adhesive composition according to any one of claims 1 to 5 is characterized by comprising cross-linked. A pressure-sensitive adhesive sheet or tape for curing, wherein a pressure-sensitive adhesive layer comprising the peelable aqueous pressure-sensitive adhesive composition according to any one of claims 1 to 6 is laminated on a substrate.