JP2020083921A - Adhesive composition, curable composition and article containing the same, and method for producing adhesive product - Google Patents

Abstract

To provide an adhesive composition that has excellent adhesive strength while maintaining holding strength.SOLUTION: Provided is an adhesive composition containing a compound having at least two partial structures represented by the following formula (I) in the molecule and a (meth)acrylic polymer. (In formula (I), Rand Rare each independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, or Rand Rtogether form a divalent hydrocarbon group having 3 to 15 carbon atoms.).SELECTED DRAWING: None

Description

The present invention relates to a pressure-sensitive adhesive composition, a curable composition, an article containing them, and a method for producing a pressure-sensitive adhesive product.

The pressure-sensitive adhesive (pressure-sensitive adhesive) composition is used in a wide variety of applications such as kraft tapes, sticking supports for medical first-aid bandages, surgical tapes, conductive tapes, and the like. As the pressure-sensitive adhesive composition, conventionally, many compositions containing an acrylic polymer as a main component are known (Patent Document 1).

Japanese Patent Laid-Open No. 5-112764 Japanese Patent Publication No. 2018-502852 Japanese Patent Publication No. 2015-517973

Here, as the pressure-sensitive adhesive composition, an acrylic polymer having a glass transition temperature of 0° C. or lower in order to improve the holding power and the pressure-sensitive adhesive property, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent and/or a metal-based crosslinking agent. Although a cross-linked product has been developed, the present inventors have made diligent studies and found that such an adhesive has a limit in improving the adhesive force while maintaining the holding force. ..

The present invention has been made in view of the above circumstances, and provides a pressure-sensitive adhesive composition having excellent pressure-sensitive adhesive strength while maintaining a holding force, an article including the pressure-sensitive adhesive composition, and a method for manufacturing a pressure-sensitive adhesive product. The purpose is to do.

（式（Ｉ）において、Ｒ^１及びＲ^２は、それぞれ独立に水素原子、１〜１５個の炭素原子を有する一価の炭化水素基、又はＲ^１及びＲ^２が一緒になって３〜１５個の炭素原子を有する２価の炭化水素基を形成している。） The pressure-sensitive adhesive composition of the present invention contains a compound having at least two partial structures represented by the following formula (I) in the molecule, and a (meth)acrylic polymer.

(In the formula (I), R ¹ and R ² are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R ¹ and R ² together are 3 to 15; Forming a divalent hydrocarbon group having 1 carbon atom.)

The above compound has an n-valent hydrocarbon group that connects the n (n is an integer of 2 to 5) partial structures, and the n-valent hydrocarbon group has 2 to 20 carbon atoms. preferable.

The pressure-sensitive adhesive composition preferably contains 0.01 to 10 parts by mass of the compound with respect to 100 parts by mass of the (meth)acrylic polymer.

（式（ＩＩ）において、Ｒ^１及びＲ^２は、それぞれ独立に水素原子、１〜１５個の炭素原子を有する一価の炭化水素基である、又はＲ^１及びＲ^２が一緒になって３〜１５個の炭素原子を有する２価の炭化水素基を形成しており、Ｒ^３及びＲ^４は、それぞれ独立に１〜３０個の炭素原子を有する１価の有機基を表す、又はＲ^３及びＲ^４が一緒になって３〜３０個の炭素原子を有する２価の有機基を形成している。） In the pressure-sensitive adhesive composition of the present invention, a diester compound represented by the following formula (II) and a polyhydric alcohol are reacted under conditions in which a transesterification reaction occurs between the diester compound and the polyhydric alcohol. It may contain a compound that is a reaction product and a (meth)acrylic polymer.

(In the formula (II), R ¹ and R ² are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R ¹ and R ² together are 3 Forming a divalent hydrocarbon group having 15 to 15 carbon atoms, R ³ and R ⁴ each independently represent a monovalent organic group having 1 to 30 carbon atoms, or R ³ And R ⁴ together form a divalent organic group having 3 to 30 carbon atoms.)

The diester compound represented by the formula (II) is preferably at least one selected from the group consisting of dimethyl methylenemalonate, diethyl methylenemalonate, di-n-hexyl methylenemalonate and dicyclohexylmethylenemalonate.

The pressure-sensitive adhesive composition preferably contains 0.01 to 10 parts by mass of the reaction product with respect to 100 parts by mass of the (meth)acrylic polymer.

The pressure-sensitive adhesive composition preferably further contains a basic compound.

It is preferable that the (meth)acrylic polymer has a structural unit containing a carboxyl group.

The content of the basic compound is 0.001 with respect to 100 mol% of the carboxyl group in terms of the number of moles of the monovalent acid required to completely neutralize the basic compound stoichiometrically. It is preferably about 20 mol%.

It is preferable that the (meth)acrylic polymer has a glass transition temperature of −100 to −10° C.

（式（Ｉ）において、Ｒ^１及びＲ^２は、それぞれ独立に水素原子、１〜１５個の炭素原子を有する炭化水素基、又はＲ^１及びＲ^２が一緒になって３〜１５個の炭素原子を有する２価の炭化水素基を形成している。） The curable composition of the present invention comprises a compound having at least two partial structures represented by the following formula (I) in the molecule and a (meth)acrylic-based polymer having a glass transition temperature of -100°C to -10°C. Including and.

(In formula (I), R ¹ and R ² are each independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, or R ¹ and R ² together form 3 to 15 carbon atoms. It forms a divalent hydrocarbon group having atoms.)

The method for producing a pressure-sensitive adhesive product of the present invention comprises a step of applying the pressure-sensitive adhesive composition or curable composition to a support, and at least partially curing the pressure-sensitive adhesive composition or curable composition applied to the support. Forming a pressure-sensitive adhesive layer.

The article of the present invention includes a base material and a resin composition layer formed on the surface of the base material, and the resin composition layer contains the pressure-sensitive adhesive composition or the curable composition.

According to the present invention, it is possible to provide a pressure-sensitive adhesive composition having an excellent pressure-sensitive adhesive force while maintaining a holding force, an article including the pressure-sensitive adhesive composition, and a method for producing a pressure-sensitive adhesive product.

The pressure-sensitive adhesive composition (also referred to as a pressure-sensitive adhesive composition) of the present embodiment comprises a compound having at least two partial structures represented by the following formula (I) in the molecule, and a (meth)acrylic polymer. ,including. In the following, the above compound is also simply referred to as a crosslinking agent.

（式（Ｉ）において、Ｒ^１及びＲ^２がそれぞれ独立に水素原子、１〜１５個の炭素原子を有する炭化水素基又はＲ^１及びＲ^２が一緒になって３〜１５個の炭素原子を有する２価の炭化水素基を形成している。）

(In the formula (I), R ¹ and R ² are each independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, or R ¹ and R ² are taken together to form 3 to 15 carbon atoms. It has a divalent hydrocarbon group.)

The pressure-sensitive adhesive composition of the present embodiment has an excellent pressure-sensitive adhesive force while maintaining the holding force, unlike the pressure-sensitive adhesive composition using a conventional crosslinking agent such as isocyanate. The reason why it is difficult to improve the adhesive strength while maintaining the holding power of the pressure-sensitive adhesive composition using a conventional isocyanate-based crosslinking agent is not necessarily clear, but the present inventors have the following. thinking. Conventional isocyanate-based and epoxy-based cross-linking agents are obtained from the cross-linking agents because they are partially deactivated before the cross-linking reaction with the (meth)acrylic polymer or the cross-linking reaction is slow. It is considered that an uncrosslinked (meth)acrylic polymer is present in the adhesive layer of the adhesive product even after the adhesive product is attached, and this influences the improvement of the adhesive power while maintaining the holding power. It is thought that it was difficult. On the other hand, the cross-linking agent of the present embodiment is hard to deactivate and undergoes a rapid cross-linking reaction. Therefore, by the time the adhesive product is attached, the (meth)acrylic polymer is entirely cross-linked in the adhesive layer as designed. It is thought that it has become.

In the formula (I), the number of carbon atoms of the hydrocarbon group represented by R ¹ and R ² is preferably 1 to 10 and more preferably 1 to 5. Specific examples of R ¹ and R ² include methyl group, ethyl group, n-butyl group, n-pentyl group (amyl group), n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group. , N-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, isopropyl group, 2-methylbutyl group, isoamyl group, 3,3-dimethylbutyl group, 2-ethylbutyl group, 2-ethyl-2-methylpropyl group, isoheptyl group, isooctyl group, 2-ethylhexyl group, 2-propylpentyl group, neononyl group, 2-ethylheptyl group, 2-propylhexyl group, 2-butyl Pentyl group, isodecyl group, neodecyl group, 2-ethyloctyl group, 2-propylheptyl group, 2-butylhexyl group, isoundecyl group, neoundecyl group, 2-ethylnonyl group, 2-propyloctyl group, 2-butylheptyl group, 2-pentylhexyl group, isododecyl group, neododecyl group, 2-ethyldecyl group, 2-propylnonyl group, 2-butyloctyl group, 2-pentylheptyl group, isotridecyl group, neotridecyl group, 2-ethylundecyl group, 2- Propyldecyl group, 2-butyloctyl group, 2-pentyloctyl group, 2-hexylheptyl group, isotetradecyl group, neotetradecyl group, 2-ethyldodecyl group, 2-propylundecyl group, 2-butyldecyl group, Examples thereof include a 2-pentylnonyl group, a 2-hexyloctyl group, an isopentadecyl group, a neopentadecyl group, a cyclohexylmethyl group and a benzyl group.

At least one of R ¹ and R ² may be a hydrogen atom, or both may be a hydrogen atom.

When R ¹ and R ² together form a divalent hydrocarbon group having 3 to 15 carbon atoms, the divalent hydrocarbon group preferably has 4 to 12 carbon atoms. , 5 to 9 are more preferable. Specific examples of the divalent hydrocarbon group include 1,3-propylene group, 1,4-butylene group, 1,5-pentylene group, 1,6-hexylene group and 1,5-hexylene group. Can be mentioned.

The content of the compound represented by the formula (I) in the pressure-sensitive adhesive composition is 0.01 to 10 with respect to 100 parts by mass of the acrylic polymer, from the viewpoint of further improving the pressure-sensitive adhesive force while maintaining the holding force. It is preferably mass part, preferably 0.1 to 5 mass part, and more preferably 0.5 to 3 mass part.

The weight average molecular weight of the cross-linking agent is preferably 300 to 10,000, more preferably 300 to 5,000, and further preferably 400 to 3,000.

The weight average molecular weight of the cross-linking agent refers to the weight average molecular weight measured by gel permeation chromatography (GPC). Specifically, the weight average molecular weight was measured using a standard polystyrene [Tosoh Co., Ltd., Tosoh Co., Ltd. product number: HLC-8220GPC, a separation column Tosoh Co., Ltd. product number: TSKgel Super Multipore HZ-N. Manufactured by KK].
For a cross-linking agent for which measurement under the above conditions is not appropriate, the above conditions may be measured with appropriate minimum changes.

The compound of formula (I) is produced by reacting a diester compound represented by the following formula (II) and a polyhydric alcohol under conditions in which a transesterification reaction occurs between the diester compound and the polyhydric alcohol. can do. That is, the cross-linking agent may be a reaction product obtained by reacting the diester compound represented by the formula (II) and the polyhydric alcohol under the condition that the transesterification reaction occurs.

（式（ＩＩ）において、Ｒ^１及びＲ^２は、式（Ｉ）のＲ^１及びＲ^２と同じ意味であり、Ｒ^３及びＲ^４は、それぞれ独立に１〜３０個の炭素原子を有する１価の有機基を表す。）

(In Formula (II), R ¹ and R ² have the same meanings as R ¹ and R ² in Formula (I), and R ³ and R ⁴ each independently have 1 to 30 carbon atoms. Represents a valent organic group.)

The transesterification reaction between the diester compound represented by the formula (II) and the polyhydric alcohol can be carried out under an acid catalyst or an acid in the ester form. Such a reaction is described, for example, in JP-T-2018-502852, JP-T-2015-517973, and the like.

The acid catalyst used in the transesterification reaction is not particularly limited, but trifluoromethanesulfonic acid (triful acid), fluorosulfonic acid, sulfuric acid, methanesulfonic acid, sulfated tin oxide, triflated tin oxide, sulfated Examples thereof include zirconia, triflated zirconia, triflated HZSM-5, phosphoric acid, tetrafluoroborate diethyl ether complex, Amberlyst 15 water form (heterogeneous sulfuric acid), and Nafion NR15 (heterogeneous trifluoromethanesulfonic acid). Examples of the ester type acid include alkyl triflate, ethyl triphthalate, dibutyl sulfate and the like. The transesterification reaction may be performed by heating, for example, at a temperature of 80 to 160°C.

R ³ and R ⁴ are monovalent organic groups, and examples of such an organic group include monovalent hydrocarbon groups having 1 to 30 carbon atoms or carbon atoms having 1 to 15 carbon atoms. At least one hydrogen atom of a hydrogen group is halogen, an alkoxy group having 1 to 15 carbon atoms, a hydroxyl group, a nitro group, an azido group, a cyano group, an acyloxy group, a carboxyl group and an alkyl group having 1 to 15 carbon atoms. Examples thereof include a monovalent group substituted with a substituent selected from the group consisting of ester groups, or a group having a heterocycle. The monovalent group preferably has 1 to 5 or less substituents, and more preferably 1 to 3 substituents. Examples of the heterocycle include a tetrahydrofurfuryl group.

The number of carbon atoms of the monovalent hydrocarbon group for R ³ and R ⁴ is preferably 1 to 20, more preferably 1 to 15, and further preferably 1 to 10. preferable. The hydrocarbon group may be any of an aliphatic hydrocarbon group and an aromatic hydrocarbon group, the aliphatic hydrocarbon group, a linear aliphatic hydrocarbon group, a branched aliphatic hydrocarbon group, And an alicyclic hydrocarbon group. Moreover, the aliphatic hydrocarbon group may be either a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aromatic hydrocarbon group is a group having an aromatic ring and may have an aliphatic portion, and the alicyclic hydrocarbon group is a group having a cyclic aliphatic hydrocarbon portion. It may have a linear or branched aliphatic hydrocarbon moiety.

As the linear saturated hydrocarbon group, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group (amyl group), an n-hexyl group, an n-heptyl group, an n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, Examples thereof include n-nonadecyl group, n-icosyl group, n-henicosyl group, and n-docosyl group.

Examples of the branched chain saturated hydrocarbon group include isopropyl group, sec-butyl group, isobutyl group, tert-butyl group, 1-methylbutyl group, 1-ethylpropyl group, 2-methylbutyl group, isoamyl group, 1,2-dimethyl group. Propyl group, 1,1-dimethylpropyl group, tert-amyl group, 1,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1-methylpentyl group, 1-methylbutyl group, 1-ethylbutyl group, 2- Ethylbutyl group, 2-ethyl-2-methylpropyl group, sec-heptyl group, tert-heptyl group, isoheptyl group, sec-octyl group, tert-octyl group, isooctyl group, 1-ethylhexyl group, 1-propylpentyl group, 2-ethylhexyl group, 2-propylpentyl group, sec-nonyl group, tert-nonyl group, neononyl group, 1-ethylheptyl group, 1-propylhexyl group, 1-butylpentyl group, 2-ethylheptyl group, 2- Propylhexyl group, 2-butylpentyl group, isodecyl group, sec-decyl group, tert-decyl group, neodecyl group, 1-ethyloctyl group, 1-propylheptyl group, 1-butylhexyl group, 2-ethyloctyl group, 2-propylheptyl group, 2-butylhexyl group, isoundecyl group, sec-undecyl group, tert-undecyl group, neoundecyl group, 1-ethylnonyl group, 1-propyloctyl group, 1-butylheptyl group, 1-pentylhexyl group , 2-ethylnonyl group, 2-propyloctyl group, 2-butylheptyl group, 2-pentylhexyl group, isododecyl group, sec-dodecyl group, tert-dodecyl group, neododecyl group, 1-ethyldecyl group, 1-propylnonyl group , 1-butyloctyl group, 1-pentylheptyl group, 2-ethyldecyl group, 2-propylnonyl group, 2-butyloctyl group, 2-pentylheptyl group, isotridecyl group, sec-tridecyl group, tert-tridecyl group, neotridecyl group Group, 1-ethylundecyl group, 1-propyldecyl group, 1-butylnonyl group, 1-pentyloctyl group, 1-hexylheptyl group, 2-ethylundecyl group, 2-propyldecyl group, 2-butyloctyl group , 2-pentyloctyl group, 2-hexylheptyl group, isotetradecyl group, sec-tetradecyl group, tert-tetradecyl group, neotetradecyl group, 1-ethyldodecyl group, 1-propylundecyl group, 1-butyldecyl group , 1-pentylnonyl group, 1-hexyloctyl group, 2-ethyldodecyl group, 2-propylundecyl group, 2-butyldecyl group, 2-pentylnonyl group, 2-hexyloctyl group, isopentadecyl group, sec-pentadecyl group Group, tert-pentadecyl group, neopentadecyl group, isohexadecyl group, sec-hexadecyl group, tert-hexadecyl group, neohexadecyl group, isoheptadecyl group, sec-heptadecyl group, tert-heptadecyl group, neoheptadecyl group, isooctadecyl group (Isostearyl) group, sec-octadecyl group, tert-octadecyl group, neooctadecyl group, isononadecyl group, sec-nonadecyl group, tert-nonadecyl group, neononadecyl group, isoicosyl group, sec-icosyl group, tert-icosyl group, neoicosyl group Group, isohenicosyl group, sec-henicosyl group, tert-henicosyl group, neohenicosyl group, isodocosyl group, sec-docosyl group, tert-docosyl group, neodocosyl group, isotricosyl group, sec-tricosyl group, tert-tricosyl group, neotricosyl group, Isotetracosyl group, sec-tetracosyl group, tert-tetracosyl group, neotetracosyl group, isopentacosyl group, sec-pentacosyl group, tert-pentacosyl group, neopentacosyl group, isohexacosyl group, sec-hexacosyl group, tert-hexacosyl group, neohexacosyl group, isoheptacosyl group , Sec-heptacosyl group, tert-heptacosyl group, neoheptacosyl group, isooctacosyl group, sec-octacosyl group, tert-octacosyl group, neooctacosyl group, isononacosyl group, sec-nonacosyl group, tert-nonacosyl group, neononacosyl group, isotriacontyl group Group, sec-triacontyl group, tert-triacontyl group and the like.

Examples of the alicyclic hydrocarbon group include cyclopentyl group, cyclohexyl group, cyclohexyl group, cyclooctyl group, methylcyclohexyl group, cyclohexylmethyl group, adamantyl group and norbornyl group.

Examples of the unsaturated hydrocarbon group include a linear alkenyl group and a branched chain alkenyl group, and specific examples of the linear alkenyl group include a vinyl group, an allyl group, a 1-butenyl group, a 2-butenyl group, Examples thereof include a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, a nonenyl group, a decenyl group, a dodecenyl group, an octadecenyl group and an icosenyl group.
Examples of the branched alkenyl group include isopropenyl group, isobutenyl group, isopentenyl) group, isohexenyl group, isoheptenyl group, isooctenyl group, isononenyl group, isodecenyl group, isododecenyl group, isooctadecenyl group, isoicosenyl group and the like.

Examples of the aromatic hydrocarbon group include phenyl group; naphthyl group; aralkyl group such as benzyl group, 1-phenylethyl group, 2-phenylethyl group, 3-phenylpropyl group, 4-phenylbutyl group; styryl group. (Ph-CH = C- group); a cinnamyl group (Ph-CH = CHCH ₂ - group); 1-benzocyclobutenyl group; 1,2,3,4-tetrahydronaphthyl group, etc. distyrenated phenyl group can be mentioned Be done.

When R ³ and R ⁴ together form a divalent organic group having 3 to 30 carbon atoms, the carbon number of the divalent organic group is preferably 3 to 10 and 3 ~6 is more preferable. Further, the divalent organic group may be a divalent hydrocarbon group, and specific examples of the divalent hydrocarbon group include a 2,2-propylene group, a 1,3-propylene group and 1,4- Examples thereof include a butylene group, a 1,5-pentylene group, a 1,6-hexylene group, and a 1,5-hexylene group. The divalent organic group may be a group in which one or more hydrogen hydrogen atoms of a divalent hydrocarbon group having 3 to 15 carbon atoms are substituted with a substituent. Examples of the substituent include the substituents exemplified when R ³ and R ⁴ are monovalent organic groups. The divalent organic group preferably has 1 to 5 or less, and more preferably 1 to 3 substituents.

Examples of the compound represented by the formula (II) include methylpropyl methylene malonate, dihexyl methylene malonate, dicyclohexyl methylene malonate, diisopropyl methylene malonate, butyl methyl methylene malonate, ethoxyethyl ethyl methylene malonate, and methoxyethyl methylene malonate. Methyl, hexyl ethyl methylene malonate, dipentyl methylene malonate, ethyl pentyl methylene malonate, methyl pentyl methylene malonate, ethyl ethyl methylene malonate methoxyl, ethoxyethyl methyl methylene malonate, butyl ethyl methylene malonate, dibutyl methylene malonate, methylene Diethyl malonate (DEMM), diethoxyethyl methylene malonate, dimethyl methylene malonate, di-N-propyl methylene malonate, ethylhexyl methylene malonate, phenethyl methyl methylene malonate, menthyl methyl methylene malonate, methylene malonate 2 -Phenylpropylethyl, 3-phenylpropyl methylenemalonate, dimethoxyethyl methylenemalonate and the like.

The polyhydric alcohol is not particularly limited, but is preferably a divalent to pentavalent alcohol, and more preferably a divalent or trivalent alcohol. Examples of the dihydric alcohol include alkylene glycols having 2 to 20 carbon atoms, and specifically,
_{Formula; HO-C m H 2m +} 1 -OH ( in m, is an integer of 2 to 15, preferably 2 to 10, 1 to 6 is preferred.)
The compound represented by is specifically mentioned, specifically, ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,5-pentylene glycol, 1,6-hexylene glycol, 1,4. -Cyclohexanedimethanol, 1,4-benzenedimethanol and the like can be mentioned.
Further, as the divalent alcohol,
_{Formula; HO- (C r H 2r +} 1 -O) s -H (r is an integer from 2 to 5, preferably from 2 to 3, s is an integer from 2 to 50, 5 30 is preferable, and 5 to 20 is more preferable.).
Examples of trihydric or higher alcohols include compounds such as glycerin, polyglycerin, erythritol, xylitol, sorbitol, trimethylolpropane, pentaerythritol, and dipentaerythritol.

That is, the cross-linking agent has a partial structure represented by the formula (I) and a polyhydric alcohol residue that connects two or more of the partial structure. When the n-valent (n is an integer of 2 to 5) alcohol is one in which a hydrogen atom of a hydrocarbon compound having 2 to 20 carbon atoms is substituted with n hydroxyl groups, a compound of the formula (II) And the reaction with a polyhydric alcohol, the crosslinking agent contains an n-valent hydrocarbon group (that is, a residue of a polyhydric alcohol) in which n pieces of the partial structure represented by the formula (I) are linked.

Further, the cross-linking agent may have a group in which one or two hydrogen atoms of the above n-valent hydrocarbon group are substituted with a hydroxyl group. In this case, n is preferably 2-4.

Further, the n-valent hydrocarbon group may be a linear or branched aliphatic hydrocarbon group, an aromatic hydrocarbon group, or an alicyclic hydrocarbon group.

At least one of R ³ and R ⁴ of formula (II) may be unreacted in the reaction. Therefore, the cross-linking agent may have, as an end group, a group in which at least one of R ³ and R ⁴ , which is the above-mentioned monovalent organic group, is bonded to one oxygen atom of the partial structure of formula (I). ..

<(Meth)acrylic polymer>
The pressure-sensitive adhesive composition of the present embodiment contains a (meth)acrylic polymer together with the cross-linking agent. The (meth)acrylic polymer is not particularly limited, and a (meth)acrylic polymer that is usually used for (meth)acrylic pressure-sensitive adhesives can be used.

The (meth)acrylic polymer contains a structural unit derived from an alkyl(meth)acrylic acid ester. The structural unit derived from the alkyl (meth)acrylic acid ester may be the main component in the (meth)acrylic polymer. The alkyl group of the alkyl (meth)acrylic acid ester is preferably an alkyl group having 1 to 20 carbon atoms. The alkyl group may be a straight chain, branched chain or alicyclic alkyl group.

Specific examples of the alkyl(meth)acrylic acid ester include methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, isopropyl acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, t-. Butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, 2-ethylhexylcarbitol (meth)acrylate, Examples thereof include isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate and cyclododecyl (meth)acrylate.

The content of the structural unit derived from the alkyl (meth)acrylic acid ester is preferably 50 to 95 mass% and more preferably 60 to 90 mass% with respect to the total mass of the (meth)acrylic polymer. ..

The (meth)acrylic polymer preferably contains a structural unit having a carboxyl group. In the present specification, those in which the content of the structural unit having a carboxyl group is 10% by mass or less based on the total amount of the (meth)acrylic polymer is referred to as a (meth)acrylic polymer. The content of the structural unit having a carboxyl group is preferably 0.1 to 10% by mass, more preferably 1 to 8% by mass, and more preferably 2 to 7% by mass based on the total mass of the (meth)acrylic polymer. More preferably, it is mass %. The (meth)acrylic polymer may not include a structural unit having a carboxyl group.

The structural unit having a carboxyl group may be bonded to any of the polymer chains of the (meth)acrylic polymer by a covalent bond, for example, may be bonded to the main chain or may be bonded to the graft chain. May be. Further, it may be bonded to the end of the polymer chain or may be bonded to a portion other than the end of the main chain. For example, examples of the monomer having a carboxyl group include monocarboxylic acids, dicarboxylic acids, and dicarboxylic acid monoesters. More specifically, (meth)acrylic acid, maleic acid, fumaric acid, crotonic acid, cinnamic acid, itaconic acid, citraconic acid, maleic anhydride, monomethyl maleate, monobutyl maleate, itaconic anhydride, monomethyl itaconate. , Monobutyl itaconic acid, vinyl benzoic acid, monohydroxyethyl (meth)acrylate oxalate, carboxyl group-terminated caprolactone modified acrylate (for example, "Plaxel FA" series; manufactured by Daicel Industries, Ltd.), carboxyl group-terminated caprolactone modified methacrylate (for example, "Plaxel FMA") Series; manufactured by Daicel Industries, Ltd.) and the like. Among these, (meth)acrylic acid and itaconic acid are preferable. These can be used by appropriately selecting one kind or two or more kinds. Further, the monomer having a carboxyl group may be used as a salt in which the carboxyl group is neutralized.

The carboxyl group includes a salt of the carboxyl group. Salts of carboxyl groups also contribute to crosslinking. A salt of a carboxyl group may be included if desired such as pot life. Although the salt of the carboxyl group is not limited, examples thereof include ammonium salts, organic ammonium salts, metal salts, and the like, and salts of alkali metals and organic amines are preferable. For example, a salt of a carboxyl group can be obtained by neutralizing a (meth)acrylic polymer. Out of 100 mol% of carboxyl groups contained in the (meth)acrylic polymer, 50 mol% or less may be a salt, and 1 to 30 mol% may be a salt.

When the (meth)acrylic polymer has a hydroxyl group, the (meth)acrylic polymer may have a structural unit derived from a hydroxyl group-containing (meth)acrylic acid ester. Examples of the hydroxyl group-containing (meth)acrylic acid ester include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxy. Examples thereof include butyl (meth)acrylate and caprolactone-modified hydroxy (meth)acrylate (for example, "Plaxel F" series manufactured by Daicel Chemical Industries).

The content of the structural unit derived from the hydroxyl group-containing (meth)acrylic acid ester in the (meth)acrylic polymer is preferably 3 parts by mass or less based on the total amount of the (meth)acrylic polymer, and 0 It is more preferably 0.03 to 1% by mass, further preferably 0.1 to 1% by mass, and may be substantially 0% by mass. The hydroxyl value of the acrylic polymer is preferably 100 or less, more preferably 50 or less, and may be substantially 0.

The (meth)acrylic polymer may include a structural unit derived from an alkoxyalkyl (meth)acrylic acid ester, and examples of such a monomer include methoxybutyl (meth)acrylate and methoxyethyl (meth). Examples thereof include acrylate, ethoxybutyl (meth)acrylate, and trimethylolpropane tripropoxy (meth)acrylate.

The (meth)acrylic polymer is an aromatic unsaturated hydrocarbon compound such as styrene or α-methylstyrene, a vinyl ester of a monocarboxylic acid having 1 to 5 carbon atoms such as vinyl acetate or vinyl propionate, or dimethyl (meth). It may contain structural units derived from vinyl compounds such as acrylamide, diethyl (meth)acrylamide, isopropyl (meth)acrylamide, (meth)acryloylmorpholine, N-vinylpyrrolidone, and (meth)acrylonitrile. The content of the structural unit derived from the vinyl compound in the (meth)acrylic polymer is preferably 1 to 20 mass% with respect to the total mass of the (meth)acrylic polymer, and 2 to 10 mass. % Is more preferable.

The (meth)acrylic polymer can be prepared by polymerizing a monomer component corresponding to the above structural unit. When polymerizing the monomer component, a chain transfer agent or a polymerization initiator can be used. The molecular weight of the (meth)acrylic polymer can be easily adjusted by adjusting the amount of the chain transfer agent.

Examples of the chain transfer agent include 2-mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioglycolate, octyl 3-mercaptopropionic acid, and 2-mercapto. Thiol compounds such as ethanesulfonic acid, n-dodecyl mercaptan, octyl mercaptan and butyl thioglycolate; halides such as carbon tetrachloride, methylene chloride, bromoform and bromotrichloroethane; secondary alcohols such as isopropanol; phosphorous acid and the like. Examples thereof include salts, hypophosphorous acid and salts thereof, sulfurous acid and salts thereof, hydrogen sulfite and salts thereof, dithionous acid and salts thereof, metabisulfite and salts thereof, and the like.

The amount of the chain transfer agent cannot be determined unconditionally because it depends on the molecular weight of the target (meth)acrylic polymer, so it is adjusted appropriately according to the molecular weight of the target (meth)acrylic polymer. Preferably.

Examples of the polymerization initiator include an azo polymerization initiator and a peroxide polymerization initiator, and these may be used alone or in combination of two or more kinds.

Examples of the azo-based polymerization initiator include azoisobutyronitrile, 2,2'-azobisisobutyronitrile, 2,2'-azobis-(2-methylbutyronitrile) and the like. These azo polymerization initiators may be used alone or in combination of two or more.

Examples of peroxide-based polymerization initiators include tert-butylperoxy-2-ethylhexanoate, benzoyl peroxide, ditert-butyl peroxide, and the like. These peroxide-based polymerization initiators may be used alone or in combination of two or more kinds.

The amount of the polymerization initiator is not particularly limited, but is usually 0.001 to 20 parts by mass, more preferably 0.01 to 10 parts by mass, per 100 parts by mass of the raw material monomer of the (meth)acrylic polymer. is there.

A solvent may be used when polymerizing the monomer components. Examples of the solvent include aliphatic hydrocarbon compounds such as n-hexane and n-hepta; aromatic compounds such as benzene, toluene and xylene; alcohols such as isopropyl alcohol and n-butyl alcohol; propylene glycol methyl ether and dipropylene glycol. Ethers such as methyl ether, ethyl cellosolve, butyl cellosolve; esters such as ethyl acetate, butyl acetate, cellosolve acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diacetone alcohol; organic solvents such as amides such as dimethylformamide .. These solvents may be used alone or in combination of two or more. Among the solvents, aliphatic hydrocarbon compounds, alcohols, ethers, esters, ketones and amides are preferable, aliphatic hydrocarbon compounds and esters are more preferable, and n-hexane and ethyl acetate are preferable from the viewpoint of reducing the effect on the human body. More preferable.

The (meth)acrylic polymer can be prepared as described above. The weight average molecular weight of the (meth)acrylic polymer is preferably 200,000 or more, more preferably 300,000 or more, from the viewpoint of improving the tackiness of the pressure-sensitive adhesive composition, and the pressure-sensitive adhesive retention of the pressure-sensitive adhesive composition, From the viewpoint of improving tackiness, adhesiveness at curved surfaces and adhesiveness at corners, it is preferably 1.5 million or less, more preferably 1 million or less.

In the present specification, the weight average molecular weight of the (meth)acrylic polymer means the weight average molecular weight measured by gel permeation chromatography (GPC). As the weight average molecular weight, more specifically, as a measuring device, Tosoh Co., Ltd., product number: HLC-8220GPC is used, as a separation column, Tosoh Co., Ltd., product number: TSKgel Super HZM-M, and It can be a value converted by polystyrene [manufactured by Tosoh Corporation].
For a (meth)acrylic polymer for which measurement under the above conditions is not appropriate, the above conditions may be measured with appropriate minimum changes.

The glass transition temperature of the (meth)acrylic polymer is preferably − from the viewpoint of improving the tackiness retention, tackiness, adhesiveness at curved surfaces and adhesiveness at corners of the adhesive composition of the present embodiment. 100° C. or higher, more preferably −90° C. or higher, further preferably −80° C. or higher, and −10° C. or lower, preferably −20° C. or lower from the viewpoint of improving the tackiness of the pressure-sensitive adhesive composition of the present embodiment, The temperature is more preferably -30°C or lower, still more preferably -35°C or lower.

The glass transition temperature of the (meth)acrylic polymer is calculated by using the glass transition temperature of a homopolymer of a monomer used as a monomer component constituting the (meth)acrylic polymer, and the formula:
1/Tg=Σ(Wm/Tgm)/100
[In the formula, Wm represents the content rate (% by weight) of the monomer m in the monomer component constituting the polymer, and Tgm represents the glass transition temperature (absolute temperature: K) of the homopolymer of the monomer m. ]
It means the temperature determined based on the Fox equation.

The glass transition temperature of the (meth)acrylic polymer (nonvolatile content) is the glass transition of a homopolymer composed of a monomer contained in a monomer component used as a raw material of the (meth)acrylic polymer. From the temperature (Tg) (absolute temperature: K) and the mass fraction of the monomer, the formula (1):
1/Tg=W ₁ /Tg ₁ +W ₂ /Tg ₂ +W ₃ /Tg ₃ +... +W _n /Tg _n (1)
Wherein, Tg is in the seek glass transition temperature of the (meth) acrylic polymer _{(K), W 1, W} 2, W 3 ···· W n is the weight fraction of each of monomer _{rate, Tg 1, Tg 2, Tg} 3 ···· Tg n are respectively the glass transition temperature (K) of a homopolymer composed of a monomer corresponding to the mass fraction of each monomer]
It can be obtained based on the Fox equation.

In the present specification, the glass transition temperature of the (meth)acrylic polymer means the glass transition temperature obtained based on the formula (1). For a monomer such as a special monomer or a polyfunctional monomer whose glass transition temperature is unknown, the glass transition temperature can be determined using only the monomer whose glass transition temperature is known.

The composition of the monomer component used as the raw material of the (meth)acrylic polymer can be determined in consideration of the glass transition temperature of the (meth)acrylic polymer.

The glass transition temperature of the homopolymer is, for example, 106° C. for a homopolymer of acrylic acid, 130° C. for a homopolymer of methacrylic acid, ω-carboxypolycaprolactone acrylate [trade name: Aronix (manufactured by Toagosei Co., Ltd., (Registered trademark) M-5300] homopolymer is -41°C, 2-ethylhexyl acrylate homopolymer is -70°C, n-butyl acrylate homopolymer is -56°C, and methyl acrylate homopolymer is 10°C. C., 105° C. for methyl methacrylate homopolymer, −24° C. for ethyl acrylate homopolymer, −54° C. for n-butyl acrylate homopolymer, −20° C. for n-butyl methacrylate homopolymer, n -80° C. for octyl acrylate homopolymer, −58° C. for isooctyl acrylate homopolymer, 16° C. for cyclohexyl acrylate homopolymer, 83° C. for cyclohexyl methacrylate homopolymer. Nyl methacrylate homopolymer is 180°C, 2-hydroxyethyl acrylate homopolymer is -15°C, 2-hydroxyethyl methacrylate homopolymer is 85°C, and 4-hydroxybutyl acrylate homopolymer is -32°C. Is.

The glass transition temperature of the (meth)acrylic polymer can be easily adjusted by appropriately adjusting the type and amount of the raw material monomer used when preparing the (meth)acrylic polymer.

From the viewpoint of improving storage stability, the pressure-sensitive adhesive composition of the present embodiment may contain one or more anionic polymerization inhibitors, radical polymerization inhibitors and antioxidants. As the anionic polymerization inhibitor, an acid having an acid dissociation constant in water of 2 or less is preferable, and specific examples thereof include sulfonic acids such as sulfuric acid, methanesulfonic acid and p-toluenesulfonic acid, sulfurous acid, phosphoric acid, trifluoroacetic acid. And so on. When the anionic polymerization inhibitor is contained, its content may be appropriately adjusted depending on the acidity, but from the viewpoint of balancing storage stability and reactivity, it is 0.1 to 2000 ppm with respect to the total amount of the crosslinking agent. It is preferably from 1 to 1000 ppm, more preferably from 3 to 500 ppm. As the radical polymerization inhibitor and the antioxidant, hindered phenols, sulfur-based antioxidants and phosphorus-based antioxidants are preferable from the viewpoint of color suppression, and specifically, for example, 2,6-di-t-butyl. -4-Methylphenol, 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid stearate, 2,2'-methylenebis(4-methyl-6-t-butylphenol), tetrakis(methylene) -3-(3,5-di-t-butyl-4-hydroxyphenyl)furpionate)methane, 4,4'-thiobis(3-methyl-6-t-butylphenol), 2,5-di-t-butyl Hindered phenols such as hydroquinone; sulfur-based antioxidants such as dilaurylthiodipropionate and distearylthiodipropionate; triphenylphosphite, tris(nonylphenyl)phosphite, distearylpentaerythritol diphosphite, Examples thereof include phosphorus-based antioxidants such as tetra(tridecyl)-1,1,3-tris(2-methyl-5-t-butyl-4-hydroxyphenyl)butanediphosphite. When a radical polymerization inhibitor and an antioxidant are contained, the content thereof is preferably 50 to 5000 ppm, more preferably 100 to 3000 ppm, relative to the crosslinking agent, from the viewpoint of balancing storage stability and reactivity. , And more preferably 200 to 2000 ppm.

The pressure-sensitive adhesive composition of the present embodiment may contain a non-reactive or reactive diluent from the viewpoint of avoiding excessively high viscosity and ensuring ease of handling and improving workability. .. Here, the reactive diluent means a diluent having a functional group capable of copolymerizing with the above-mentioned crosslinking agent by an anionic polymerization mechanism. When only such a reactive diluent is used as the diluent, the reactive diluent is incorporated into the crosslinking while increasing the molecular weight, so that a crosslinkable resin composition that does not require the step of removing the volatile solvent should be configured. You can On the other hand, the non-reactive diluent means a diluent having no functional group that copolymerizes with the above-mentioned crosslinking agent by an anionic polymerization mechanism.

The non-reactive diluent may be water or an organic solvent, and may be appropriately selected depending on the application, but the hydroxyl group of water tends to cause chain transfer relatively easily and tends to inhibit crosslinking of the pressure-sensitive adhesive composition. Organic solvents are preferred because they are present. The organic solvent is preferably volatile and capable of uniformly dissolving the (meth)acrylic polymer and the crosslinking agent. Specifically, for example, esters such as ethyl acetate, butyl acetate, ethyl propionate, butyl propionate, methyl lactate, ethyl lactate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate; acetone, methyl ethyl ketone, methyl isobutyl ketone, Ketones such as cyclohexanone; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, tetrahydrofuran, dioxane; dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. Amides; methanol, ethanol, isopropanol, n-butanol, s-butanol, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene Examples thereof include alcohols such as glycol monoethyl ether and 3-methoxybutanol; aromatic hydrocarbons such as benzene, toluene, xylene and ethylbenzene. These may be used alone or in combination of two or more.

Examples of the reactive diluent include monofunctional 1,1-disubstituted vinyl compounds, that is, diester compounds represented by the formula (II). Examples of such diester compounds include dimethyl methylenemalonate, diethyl methylenemalonate, di-n-butyl methylenemalonate, di-n-hexyl methylenemalonate, dicyclohexylmethylenemalonate, methylcyclohexylmethylenemalonate and methylenemalonic acid. Specific examples thereof include 2-ethylhexylmethyl, and these may be used alone or in combination of two or more kinds.

The pressure-sensitive adhesive composition of the present embodiment may contain a non-reactive diluent, for example, 0% by mass or more and 50% by mass or less, and a reactive diluent, for example, 0% by mass or more and 50% by mass. The following may be included.

The pressure-sensitive adhesive composition of this embodiment may include a basic compound. The basic compound is not particularly limited as long as it acts as a base, and various compounds such as alkali metals, basic low molecular weight compounds, high molecular compounds, and solid substances having a basic surface can be applied. Examples of the basic low molecular weight compound include metal oxides, hydroxide salts, alkoxide compounds, carboxylates, amines and the like from the viewpoint of availability and handleability. In addition, when the (meth)acrylic polymer has a salt of a carboxyl group, the basic compound may not necessarily be added, but when the (meth)acrylic polymer does not have a salt of a carboxyl group, It is preferable to add a basic compound. The basic compound may be added and used when crosslinking the pressure-sensitive adhesive composition. Alternatively, the composition may be prepared by previously mixing the (meth)acrylic polymer and the basic compound, and a crosslinking agent may be added to the composition when the composition is crosslinked. A basic compound may be added to the (meth)acrylic polymer together with the crosslinking agent. As described above, one example was given for the addition of the basic compound, but depending on the required use conditions such as adjustment of the pot life, the addition amount or addition of the basic compound within the range that does not impair the purpose or effect of the present embodiment. The method may be adjusted appropriately.

Examples of the metal oxide include basic metal oxides, and more specifically, sodium oxide (Na ₂ O), potassium oxide (K ₂ O), magnesium oxide (MgO), calcium oxide (CaO), Examples thereof include copper oxide (CuO) and zinc oxide (ZnO).

Examples of the hydroxide salt include metal hydroxides such as sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, copper hydroxide and zinc hydroxide; tetramethylammonium hydroxide, tetraethylammonium hydroxide, Ammonium hydroxides such as tetrabutylammonium hydroxide;

Examples of the alkoxide compound include compounds represented by the formula (R ⁵ O) _m1 M (wherein R ⁵ is an alkyl group or an aryl group which may have a substituent, and more specifically, May be an alkyl group or an aryl group having 1 to 10 carbon atoms, M represents a monovalent cation, and m1 is an integer of 1 to 4), more specifically sodium methoxy. And metal alkoxides such as sodium ethoxide, aluminum isopropoxide, and titanium tetraisopropoxide.

Examples of the carboxylic acid salt include salts of monocarboxylic acid and dicarboxylic acid, and may be salts of aliphatic carboxylic acid and aromatic carboxylic acid. The carboxylic acid may have 1 to 10 carbon atoms, or 1 to 6 carbon atoms. Specific examples of the carboxylic acid salt include carboxylic acid salts such as sodium formate, sodium acetate, zinc acetate, sodium benzoate, sodium oxalate, ammonium acetate, and a salt of acetic acid and triethylamine.

Amines include R ¹¹ R ¹² R ¹³ N (R ¹¹ , R ¹² , and R ¹³ each independently represent hydrogen, an alkyl group which may have a substituent, or a substituent which may have a substituent. A good aryl group, which may be bonded to each other to form a cyclic structure), for example, ammonia, butylamine, dibutylamine, triethylamine, piperidine, 1-methylpiperidine, morpholine, 4-methylmorpholine, Specific examples include pyridine, imidazole, 1-methylimidazole and tetramethylguanidine.

Examples of the basic polymer compound include a polymer compound having a structure equivalent to that of the basic low molecular weight compound described above. Specifically, for example, a structural unit derived from maleic acid or the like has a carboxyl group. A salt of a polymer containing a structural unit (polycarboxylic acid salt) (however, excluding a (meth)acrylic polymer in which the content of the structural unit having a carboxyl group is 10% by mass or less), a vinylpyridine copolymer , Polyethyleneimine, and the like.

The basic polymer compound is a (meth)acrylic polymer containing a structural unit having a carboxyl group in an amount of more than 10% by mass based on the total amount of the (meth)acrylic polymer (hereinafter referred to as a (meth)acrylic polymer). It may be a united body (B). As the (meth)acrylic polymer (B), the content of the structural unit having a carboxyl group is 50 mass% or more, preferably 70 mass, with respect to the total amount of the (meth)acrylic polymer (B). There is also one that is at least %. Examples of the (meth)acrylic polymer (B) include poly(meth)acrylic acid and salts of poly(meth)acrylic acid. Examples of salts of poly(meth)acrylic acid include salts of poly(meth)acrylic acid with alkali metals and organic amines. Of 100 mol% of the carboxyl groups contained in the (meth)acrylic polymer (B), 50 mol% or more may be a salt, and 60 mol% or more may be a salt.

When the pressure-sensitive adhesive composition of the present embodiment contains a basic compound, the content of the basic compound is preferably 0.001 to 3 parts by mass with respect to 100 parts by mass of the (meth)acrylic polymer. , 0.002 to 1.5 parts by mass.

In addition, when the (meth)acrylic polymer has a carboxyl group, the content of the basic compound in the pressure-sensitive adhesive composition is included in the (meth)acrylic polymer when it is important to secure the pot life. The content is preferably 20 mol% or less, more preferably 10 mol% or less, still more preferably 5 mol% or less with respect to 100 mol% of the carboxyl groups. Further, for example, the content of the basic compound in the pressure-sensitive adhesive composition is preferably 0.001 mol% or more, more preferably 0.01 mol% or more, still more preferably 0. It is 1 mol% or more. The number of moles of the basic compound is the number of moles of a monovalent acid required to completely neutralize the basic compound stoichiometrically.

These basic compounds may be encapsulated with some material and released by an external stimulus.

In the present embodiment, the pressure-sensitive adhesive composition may contain a polymer other than the (meth)acrylic polymer, if necessary, within a range that does not impair the object of the present invention. Further, in the pressure-sensitive adhesive composition, for example, a cationic antistatic agent, an anionic antistatic agent, an amphoteric antistatic agent, a nonionic antistatic agent, an ion conductive polymer, etc. within a range not impairing the object of the present invention. Antistatic agent, crosslinking accelerator, tackifier, modifier, pigment, filler, antiaging agent, infrared absorber, ultraviolet absorber, ultraviolet stabilizer, flame retardant, thixotropic agent, leveling agent, release agent You may include additives, such as a mold agent, a matting agent, and a defoaming agent.

Examples of the pigment or filler include zinc oxide powder, titanium oxide powder, alumina powder, carbon black such as acetylene black, calcium carbonate powder, mica powder, magnesium oxide powder, aluminum hydroxide powder, calcium hydroxide powder, and hydroxide. Examples thereof include magnesium powder, white carbon, silica powder, metal powder, and conductive particles.

The gel fraction of the pressure-sensitive adhesive composition of the present embodiment is preferably 20% by mass or more, more preferably 30% by mass or more, from the viewpoint of improving cohesive force and heat resistance. From the viewpoint of improving the ratio, it is preferably 95% by mass or less, more preferably 90% by mass or less.

The adhesive product of this embodiment has an adhesive layer formed on a base material. The base material of an adhesive product is usually used as a support for an adhesive product such as an adhesive tape. That is, the pressure-sensitive adhesive product of the present embodiment includes a support and a pressure-sensitive adhesive layer formed on the surface of the support, and the pressure-sensitive adhesive layer contains the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition may be in a cured (crosslinked) state in the pressure-sensitive adhesive layer, or may be in a non-cured state. When the pressure-sensitive adhesive composition is cured, the pressure-sensitive adhesive composition may be partially cured (that is, may be in a semi-cured state) or may be in a completely cured state. .. The pressure-sensitive adhesive composition of this embodiment can also be used as a pressure-sensitive adhesive precursor for crosslinking and use as a pressure-sensitive adhesive.

The method for producing the pressure-sensitive adhesive product of the present embodiment is not particularly limited, but the step of applying the pressure-sensitive adhesive composition or the curable composition to a support, the pressure-sensitive adhesive composition applied to the support, or curable At least partially curing the composition to form an adhesive layer.

Examples of the method of applying the pressure-sensitive adhesive composition of the present embodiment to a support include knife coaters, slot die coaters, lip coaters, roll coaters, flow coaters, spray coaters, bar coaters, dipping and the like. When the pressure-sensitive adhesive composition of the present embodiment is applied to the support, the pressure-sensitive adhesive composition may be directly applied to the support, or after being applied to release paper or the like, the pressure-sensitive adhesive composition is formed on the obtained applied product. The pressure-sensitive adhesive layer may be transferred onto a support. Thus, the pressure-sensitive adhesive composition can be formed on the support by applying the pressure-sensitive adhesive composition to the support and then drying.

Release paper may be attached to the surface of the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition formed on the support. When the release paper is attached to the surface of the pressure-sensitive adhesive layer in this way, the pressure-sensitive adhesive layer can be preferably protected. The release paper is peeled off from the surface of the adhesive layer when the adhesive tape is used. When a pressure-sensitive adhesive layer is formed on one surface of a support having a sheet shape, a tape shape, etc., a release agent should be applied to the back surface of this support to form a release agent layer. Thus, when the pressure-sensitive adhesive layer is placed inside and the pressure-sensitive adhesive sheet or pressure-sensitive adhesive tape is wound into a roll, the pressure-sensitive adhesive layer comes into contact with the release agent layer on the back surface of the support, thus protecting the surface of the pressure-sensitive adhesive layer, You can save it.

Examples of the support include papers such as high-quality paper, kraft paper, crepe paper, and glassine paper, supports made of resins such as polyethylene, polypropylene, polyester, polystyrene, polyvinyl chloride, and cellophane, woven cloth, non-woven cloth, and cloth. Textile products such as.

A pressure-sensitive adhesive layer can be formed by applying the pressure-sensitive adhesive composition on a support and then drying it. The pressure-sensitive adhesive composition may be dried and cured at the same time. Examples of the drying method include hot air and far infrared irradiation. The drying temperature is preferably 50 to 120°C, and more preferably 60 to 100°C from the viewpoint of effectively curing the pressure-sensitive adhesive composition at the same time as drying.

The thickness of the pressure-sensitive adhesive layer formed by applying the pressure-sensitive adhesive composition after drying is not particularly limited, but is usually about 1 μm to 5 mm.

As described above, the pressure-sensitive adhesive composition of the present embodiment, since it is comprehensively excellent in tackiness, tackiness retention, tackiness, adhesiveness at curved surfaces and adhesiveness at corners, for example, It can be suitably used for a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer on one or both sides of a support, a pressure-sensitive adhesive tape having only a pressure-sensitive adhesive layer without a support, and the like.

Further, the pressure-sensitive adhesive composition of the present embodiment may contain a basic compound in advance, but may be brought into contact with the basic compound when being cured. For example, when producing a pressure-sensitive adhesive product, there is a step (contact step) of applying a layer of the pressure-sensitive adhesive composition and a basic compound after coating the pressure-sensitive adhesive composition on a support. The contacting step may be performed at room temperature or in a heated state, or may be performed after the contacting step. The temperature for heating is preferably 50 to 120°C, more preferably 60 to 100°C. The basic compound used in the contacting step and the ratio of the basic compound used may be the same as in the case of previously containing the basic compound in the pressure-sensitive adhesive composition.

In the above contact step, as a method for contacting the basic compound and the layer of the pressure-sensitive adhesive composition (pressure-sensitive adhesive layer) other than the production of the pressure-sensitive adhesive product, for example, on the surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive product already manufactured, powder-like Examples of the method include, but are not limited to, spraying and mixing the basic compound (1), and applying a liquid basic compound on the surface of the pressure-sensitive adhesive layer of an already manufactured pressure-sensitive adhesive product.

When the basic compound is added to the pressure-sensitive adhesive composition of the present embodiment and mixed, the addition amount may be appropriately selected depending on the type of the basic compound and the structure of the (meth)acrylic polymer of the present embodiment. .. Further, if the basic compound to be added is a low molecular weight compound that reacts with a carboxy group to form a carboxylate, it is preferable from the viewpoint of efficient handling of the crosslinking system. The form in which such a basic compound is added and mixed can also be said to be a form in which a mixture of the (meth)acrylic polymer of the present embodiment and the crosslinking agent of the present embodiment is prepared. The form of such a composition is, for example, the basic compound is added to the (meth)acrylic polymer of the present embodiment and mixed to form a carboxylic acid salt, and then the crosslinking agent of the present embodiment is mixed. It can be obtained by a method of mixing the (meth)acrylic polymer and the crosslinking agent of the present embodiment, and then adding and mixing the basic compound, but is not limited to these methods. The pressure-sensitive adhesive layer (pressure-sensitive adhesive composition) of the pressure-sensitive adhesive product does not contain a basic compound, and the basic compound is arranged on the surface of the adherend, or the surface is a material having basicity, It may be a mode in which the adhesive layer and the basic compound are mixed when attached to the.

Further, in the present embodiment, a compound having at least two partial structures represented by the following formula (I) in the molecule, a (meth)acrylic polymer having a glass transition temperature of −100° C. to −10° C., A curable composition comprising is also provided. According to such a curable composition, deactivation is unlikely to occur, but since it rapidly reacts with a crosslinking point, it is possible to obtain an effect that a uniform curable composition can be obtained in a short time.

（式（Ｉ）において、Ｒ^１及びＲ^２は、それぞれ独立に水素原子、１〜１５個の炭素原子を有する炭化水素基、又はＲ^１及びＲ^２が一緒になって３〜１５個の炭素原子を有する２価の炭化水素基を形成している。）

(In formula (I), R ¹ and R ² are each independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, or R ¹ and R ² together form 3 to 15 carbon atoms. It forms a divalent hydrocarbon group having atoms.)

In the curable composition of the present embodiment, the above-mentioned crosslinking agent can be used as the compound having at least two partial structures represented by the following formula (I) in the molecule. Further, as the (meth)acrylic polymer, the above-mentioned (meth)acrylic polymer can be used in the range where the glass transition temperature is −100° C. to −10° C. Further, the contents of the (meth)acrylic polymer and the cross-linking agent in the curable composition of the present embodiment may be in the ranges exemplified as the contents in the pressure-sensitive adhesive composition. Further, the curable composition may be blended with components such as additives such as a basic compound and a cationic antistatic agent, which are optional components in the pressure-sensitive adhesive composition, and the content of these components may be the above-mentioned pressure-sensitive adhesive. It can be the same as the content in the agent composition.

When producing a pressure-sensitive adhesive product using the curable composition of the present embodiment, a pressure-sensitive adhesive layer containing a curable composition on a support by the same method as in the case of using the pressure-sensitive adhesive composition described above. It can be formed to produce an adhesive product. In addition, in the present embodiment, more generally, a substrate and a resin composition layer formed on the surface of the substrate are provided, and the resin composition layer is the pressure-sensitive adhesive composition or the curable composition. An article is provided which comprises: The curable composition of the present embodiment can be used for applications other than the pressure-sensitive adhesive composition, and more specifically, examples thereof include protective coatings, inks, and sealing agents.

When the curable composition of the present embodiment is used as a protective coating or the like, for example, a coating formed from the curable composition of the present embodiment on the surface of an article (referred to as a substrate) to which the curable composition is applied. Form the layers. In other words, the present embodiment can provide an article that includes a base material and a coating layer formed on the base material, and the coating layer is a cured product of the curable composition of the present embodiment.

Further, the curable composition of the present embodiment may contain a basic compound in advance, but may be brought into contact with the basic compound when being cured. In the step of contacting, a curable composition is applied to a base material containing a basic compound on the surface, and a liquid basic compound is applied to the surface of the coating layer of the curable composition already formed on the base material surface. Examples of the method include, but are not limited to, spraying a powdery basic compound onto the surface of the coating layer of the curable composition already formed on the surface of the substrate.

The base material containing a basic compound on the surface may be one in which the basic compound is arranged on the surface of the base material by spraying, depositing, or coating the basic compound, and the base material itself is basic. It may be made of the same material. Specific examples of the base material itself having basicity (solid substance having a basic surface) include basic alumina, soda lime glass, mortar, concrete and the like.

<Example 1>
[Synthesis of acrylic polymer]
72 parts by mass of ethyl acetate, 72 parts by mass of toluene, 45.3 parts by mass of 2-ethylhexyl acrylate (2EHA), and butyl acrylate (in a reaction vessel equipped with a cooling pipe, a nitrogen gas introduction pipe, a thermometer, a dropping funnel and a stirrer). BA) 40 parts by mass, acrylic acid (AA) 4.5 parts by mass, 2-hydroxyethyl acrylate (HEA) 0.2 parts by mass, vinyl acetate (VAc) 10.0 parts by mass, and then a peroxide system. After adding 0.3 parts by mass of a polymerization initiator (manufactured by NOF CORPORATION, trade name: Nyper BMT-K40) and reacting at 80° C. for 3 hours in a nitrogen gas atmosphere, a peroxide-based polymerization initiator ( 0.2 parts by mass of Nippon Oil & Fats Co., Ltd., trade name: Perhexa HC) was added and further reacted at 80° C. for 3 hours to obtain a solution of an acrylic polymer having a weight average molecular weight of 560,000. Then, the obtained acrylic polymer solution was cooled to room temperature.

[Synthesis of methylenemalonic acid ester derivative]
Diethyl methylene malonate and 1,5-pentylene glycol were mixed at a molar ratio of 5:1, and under strong acid catalyst at 130° C. and under pressure of 300 to 500 mmHg (40.0 to 66.7 kPa), 3 After heating for a period of time, a polyfunctional methylenemalonic acid ester derivative (hereinafter, also referred to as PES) having a structure in which the partial structure represented by the formula (I) is linked by a 1,5-pentyleneglycol residue is obtained. ..

To 100 parts by mass (41.0% by mass solution) of the acrylic polymer solution obtained above, 3.6 parts by mass of 0.1% by mass methanol solution of sodium benzoate was added and stirred for 30 minutes. Furthermore, the pressure-sensitive adhesive composition was obtained by adding 0.3 part by mass of the above PES.

The pressure-sensitive adhesive composition was applied to a release paper (manufactured by San-A Kaken Co., Ltd., trade name: K-80HS) using an applicator, and then dried at a temperature of 80° C. for 3 minutes. As a result, a pressure-sensitive adhesive layer having a thickness of 25 μm was formed on the release paper. A PET film support (thickness: 25 μm) was laminated on the pressure-sensitive adhesive layer to obtain a pressure-sensitive adhesive tape having one surface as an adhesive surface.

<Example 2 and Comparative Examples 1 to 3>
An adhesive tape was produced in the same manner as in Example 1 except that the composition of the adhesive composition was changed as shown in Table 1. The abbreviations of the cross-linking agents in Table 1 are as follows.
L-55: Isocyanate cross-linking agent (Tosoh Corporation, trade name: Coronate L-55E)
Tetrad C: Epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical Co., Inc., trade name: TETRAD-C)
Aluminum chelate A: Metal-based cross-linking agent (Kawaken Fine Chemicals Co., Ltd., trade name: Aluminum chelate A)

The performance of the pressure-sensitive adhesive tapes of Examples and Comparative Examples was evaluated by the following evaluation methods.

Evaluation method <Test method for initial adhesive strength>
A test piece was prepared by cutting the adhesive tape into a rectangle having a length of 50 mm and a width of 25 mm. By peeling off the release paper of the test piece, placing a stainless steel (SUS) plate whose surface is polished as an adherend on the peeled surface, and reciprocating a roll having a mass of 2 kg on the stainless steel plate, The stainless steel plate was attached to a peeling surface, allowed to stand at room temperature (about 23° C.) for 25 minutes, and then the peeling force and the fracture mode when peeling at a peeling angle of 180° and a peeling speed of 300 mm/min were measured.
Further, instead of the stainless steel plate, a glass plate or a polyethylene (PE) sheet was used as an adherend, and the peeling force and the fracture mode were measured as in the case of using the stainless steel plate. The results are shown in Table 2.

<Testing method for holding power>
Using a stainless steel plate with a polished surface as an adherend, the test piece was placed on the above stainless steel plate in an atmosphere of a temperature of 23° C. and a relative humidity of 65% in the same manner as in <Test method for initial adhesive strength>. Then, the test piece was pressure-bonded by reciprocating once with a rubber roller having a mass of 2 kg from the test piece. The pressure-bonded test piece was allowed to stand in an atmosphere having a temperature of 80° C. and a relative humidity of 65% for 20 minutes, then a 1 kg weight was attached to the end of the adhesive sheet and suspended, and allowed to stand for 1440 minutes in the atmosphere. The time required for the pressure-sensitive adhesive sheet to peel off and the length of misalignment of the pressure-sensitive adhesive sheet after 1440 minutes from the start of the test were measured. The holding power is evaluated according to the following criteria. If the evaluation is A, it can be said that the holding power is sufficient. The results are shown in Table 2.
A: The weight did not drop after 1440 minutes, and the displacement of the pressure-sensitive adhesive sheet was 1 mm or less.
B: The weight dropped before 1440 minutes had passed, or the displacement of the adhesive sheet was larger than 1 mm.

In each of the pressure-sensitive adhesive sheets of Examples 1 and 2 and Comparative Examples 1 to 3, since the fracture mode was interface fracture, no adhesive residue was observed and the holding power was sufficient. However, the pressure-sensitive adhesive sheets of Examples 1 and 2 were superior to the pressure-sensitive adhesive sheets of Comparative Examples 1 to 3 in the peeling force with respect to adherends of any material such as SUS, glass, and PE, and the pressure-sensitive adhesive force was improved. I understood.

Claims (13)

A compound having at least two partial structures represented by the following formula (I) in the molecule,
And a (meth)acrylic polymer.

(In the formula (I), R ¹ and R ² are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R ¹ and R ² together are 3 to 15; Forming a divalent hydrocarbon group having 1 carbon atom.) The compound has an n-valent hydrocarbon group connecting the n partial structures (n is an integer of 2 to 5), and the n-valent hydrocarbon group has 2 to 20 carbon atoms, The pressure-sensitive adhesive composition according to claim 1. The pressure-sensitive adhesive composition according to claim 1, comprising 0.01 to 10 parts by mass of the compound with respect to 100 parts by mass of the (meth)acrylic polymer. A diester compound represented by the following formula (II) and a polyhydric alcohol, which are reaction products obtained by reacting the diester compound and the polyhydric alcohol under a condition in which an ester exchange reaction occurs:
And a (meth)acrylic polymer.

(In the formula (II), R ¹ and R ² are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R ¹ and R ² together are 3 Forming a divalent hydrocarbon group having 15 to 15 carbon atoms, R ³ and R ⁴ each independently represent a monovalent organic group having 1 to 30 carbon atoms, or R ³ And R ⁴ together form a divalent organic group having 3 to 30 carbon atoms.) The diester compound represented by the formula (II) is at least one selected from the group consisting of dimethyl methylene malonate, diethyl methylene malonate, di-n-hexyl methylene malonate and dicyclohexyl methylene malonate. The adhesive composition described. The pressure-sensitive adhesive composition according to claim 4, comprising 0.01 to 10 parts by mass of the compound with respect to 100 parts by mass of the (meth)acrylic polymer. The pressure-sensitive adhesive composition according to claim 1, further comprising a basic compound. The pressure-sensitive adhesive composition according to claim 1, wherein the (meth)acrylic polymer has a carboxyl group. A basic compound is contained, and the content of the basic compound is converted into the number of moles of a monovalent acid necessary for completely stoichiometrically neutralizing the basic compound, and the carboxyl group is contained. The pressure-sensitive adhesive composition according to claim 8, which is 0.001 to 20 mol% with respect to 100 mol%. The pressure-sensitive adhesive composition according to any one of claims 1 to 9, wherein the (meth)acrylic polymer has a glass transition temperature of -100 to -10°C. A compound having at least two partial structures represented by the following formula (I) in the molecule,
A (meth)acrylic polymer having a glass transition temperature of -100°C to -10°C, and a curable composition.

(In formula (I), R ¹ and R ² are each independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, or R ¹ and R ² together form 3 to 15 carbon atoms. It forms a divalent hydrocarbon group having atoms.) Applying the pressure-sensitive adhesive composition according to any one of claims 1 to 10 or the curable composition according to claim 11 to a support,
And a step of at least partially curing the pressure-sensitive adhesive composition or the curable composition applied to a support to form a pressure-sensitive adhesive layer. Base material,
A resin composition layer formed on the surface of the substrate,
An article, wherein the resin composition layer contains the pressure-sensitive adhesive composition according to any one of claims 1 to 10 or the curable composition according to claim 11.