JP7348291B2 - Adhesive composition for concrete curing adhesive tape and its use - Google Patents

Description

The present invention relates to an adhesive composition for concrete curing adhesive tape and its use.

By retaining an appropriate amount of moisture in a concrete structure after pouring, internal hydration reactions proceed, improving strength and durability. As a method for manufacturing such concrete structures, there is a method in which concrete is poured into a formwork, and after being removed from the formwork, a curing sheet is attached to the surface of the concrete to keep the concrete in a moist state and cure it. A curing sheet has the effect of preventing water evaporation by covering the concrete surface. This curing sheet needs to be fixed to the concrete surface using concrete curing adhesive tape while the concrete is wet, but conventional concrete curing adhesive tapes lacked adhesion to wet surfaces. Additionally, there was a problem in that adhesive residue was left when the sheet was peeled off after curing.

In Patent Document 1, a study has been made to increase the adhesion to a wet mortar surface by adding a polyol, a polyisocyanate, and a silane coupling agent to a (meth)acrylic resin.

Although the technology is not related to adhesive tape for concrete curing, Patent Document 2 describes an adhesive tape that uses an acrylic copolymer containing 2-methoxymethyl acrylate as an adhesive tape that can adhere well to wet skin. The tape has been revealed.

Japanese Patent Publication “Unexamined Patent Publication No. 2019-19290” Japanese Patent Publication “Unexamined Patent Publication No. 2006-36911”

However, the above-mentioned conventional technology regarding concrete curing adhesive tapes has a problem in terms of pot life after addition of a silane coupling agent, and there is room for improvement for practical use.

An object of one aspect of the present invention is to provide a concrete curing adhesive tape that has excellent adhesion to a wet concrete surface and excellent re-peelability, and an adhesive composition for the concrete curing adhesive tape.

As a result of intensive studies to solve the above problems, the present inventors have discovered an adhesive composition for concrete curing adhesive tape containing a (meth)acrylic polymer containing a structural unit derived from a predetermined acrylic acid alkoxyalkyl ester monomer. The present inventors have discovered that it is possible to realize a concrete curing adhesive tape that has excellent adhesion to wet concrete surfaces and excellent re-peelability, and has completed the present invention. The present invention includes the following.

（一般式（１）中、Ｘは炭素数２～４のアルキレン基であり、Ｙは炭素数１～１０のアルキル基であり、ｎは１～１０の整数である）
で表される、アクリル酸アルコキシアルキルエステルモノマー由来の構造単位を含む、コンクリート養生粘着テープ用粘着剤組成物。An adhesive composition for concrete curing adhesive tape containing a (meth)acrylic polymer,
The (meth)acrylic polymer has the following general formula (1)

(In general formula (1), X is an alkylene group having 2 to 4 carbon atoms, Y is an alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 to 10)
An adhesive composition for a concrete curing adhesive tape, which contains a structural unit derived from an acrylic acid alkoxyalkyl ester monomer.

According to one aspect of the present invention, it is possible to realize a concrete curing adhesive tape that has excellent adhesion to a wet concrete surface and excellent removability.

An embodiment of the present invention will be described below, but the present invention is not limited thereto. The present invention is not limited to each configuration described below, and various changes can be made within the scope of the claims, and technical means disclosed in different embodiments and examples can be applied. Embodiments and examples obtained by appropriate combinations are also included in the technical scope of the present invention.

As used herein, "excellent adhesiveness" means that the adhesive product has excellent adhesive strength when attached to an adherend. Adhesiveness is evaluated by the method described in Examples below. In addition, in this specification, "excellent re-peelability" means that even if the adhesive product is left undisturbed after being attached to the adherend, even if the adhesive product is re-peeled from the adherend, the adhesive layer remains intact. is intended to be difficult to leave on the adherend. The removability is evaluated by the method described in Examples below. In this specification, "(meth)acrylic" means "methacrylic" and/or "acrylic", and "(meth)acrylate" means "acrylate and/or methacrylate". In addition, unless otherwise specified in this specification, "A to B" representing a numerical range is intended to be "A or more and B or less". In addition, in this specification, the "structural unit derived from a monomer" is preferably a structure formed by polymerizing monomers, but if the structure is the same as the structure formed by polymerizing monomers, It may be formed by a method other than polymerization.

[1 Adhesive composition for concrete curing adhesive tape]
An adhesive composition for a concrete curing adhesive tape according to an embodiment of the present invention is an adhesive composition used for a concrete curing adhesive tape, and contains a predetermined (meth)acrylic polymer.

（一般式（１）中、Ｘは炭素数２～４のアルキレン基であり、Ｙは炭素数１～１０のアルキル基であり、ｎは１～１０の整数である）
で表される、アクリル酸アルコキシアルキルエステルモノマー由来の構造単位を含む。[1.1 (meth)acrylic polymer]
The (meth)acrylic polymer contained in the adhesive composition for concrete curing adhesive tape according to one embodiment of the present invention has the following general formula (1).

(In general formula (1), X is an alkylene group having 2 to 4 carbon atoms, Y is an alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 to 10)
Contains a structural unit derived from an acrylic acid alkoxyalkyl ester monomer represented by:

（一般式（２）中、Ｘ、Ｙ、及び、ｎは一般式（１）と同様）
で表される、アクリル酸アルコキシアルキルエステルモノマーを重合させることにより、前記（メタ）アクリル系ポリマーに導入することができる。The structural unit derived from the acrylic acid alkoxyalkyl ester monomer is not particularly limited as long as it has a structure represented by the general formula (1), and for example, the structural unit derived from the following general formula (2).

(In general formula (2), X, Y, and n are the same as in general formula (1))
By polymerizing an acrylic acid alkoxyalkyl ester monomer represented by the above, it can be introduced into the (meth)acrylic polymer.

The structural unit derived from the acrylic acid alkoxyalkyl ester monomer preferably has a structure formed by polymerizing the acrylic acid alkoxyalkyl ester monomer, but is the same as the structure formed by polymerizing the acrylic acid alkoxyalkyl ester monomer. As long as it has a structure, it may be formed by a method other than the method of polymerizing an acrylic acid alkoxyalkyl ester monomer.

In the general formula (1), X may be an alkylene group having 2 to 4 carbon atoms, and may be a linear alkylene group or a branched alkylene group. Examples of X include ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, propane-1,2-diyl group, butane-1,2-diyl group, and butane-1,2-diyl group. ,3-diyl group. More preferably, X is an ethylene group, a propylene group (propane-1,2-diyl group), a trimethylene group (propane-1,3-diyl group) and a butylene group (butane-1,3-diyl group). .

In general formula (1), Y is not particularly limited as long as it is an alkyl group having 1 to 10 carbon atoms, and may be a linear alkyl group or a branched alkyl group. , or may be an alkyl group containing a ring. Examples of Y include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. More preferably, Y is a methyl group, an ethyl group, and a butyl group.

In the general formula (1), n is not particularly limited as long as it is an integer of 1 to 10, but is more preferably an integer of 1 to 3, and even more preferably an integer of 1 to 2. Further, when n is an integer of 2 or more, the plurality of Xs included in -(X-O-) _n - may be the same or different.

The acrylic acid alkoxyalkyl ester monomers represented by general formula (2) may be used alone or in combination of two or more.

The acrylic acid alkoxyalkyl ester monomer is not particularly limited, but includes, for example, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-propoxyethyl acrylate, 2-butoxyethyl acrylate, and 3-methoxypropyl acrylate. , 3-ethoxypropyl acrylate, 4-methoxybutyl acrylate, 4-ethoxybutyl acrylate, 2-methoxytriethylene glycol acrylate and the like. Among these, the acrylic acid alkoxyalkyl ester is preferably 2-methoxyethyl acrylate or 2-ethoxyethyl acrylate from the viewpoint of cohesive force, adhesive force, tack, etc. of the resulting adhesive layer.

The ratio of the structural units derived from the acrylic acid alkoxyalkyl ester monomer to the total structural units of the (meth)acrylic polymer is not particularly limited, but is preferably 50 to 99.5% by weight, and more It is preferably 60 to 99.0% by weight, more preferably 65 to 98.5% by weight, and particularly preferably 70 to 98% by weight. If the ratio of the structural units derived from the acrylic acid alkoxyalkyl ester monomer to the total structural units of the (meth)acrylic polymer is 50% by weight or more, the hydrophilicity increases and the affinity for wet surfaces increases. It is preferable because it improves Further, it is preferable that the ratio is 99.5% by weight or less, since an appropriate amount of the functional group acts as a crosslinking point.

The (meth)acrylic polymer preferably further includes a structural unit derived from a carboxyl group-containing monomer and/or a structural unit derived from a hydroxyl group-containing monomer.

The structural unit derived from the carboxyl group-containing monomer can be introduced into the (meth)acrylic polymer by, for example, polymerizing the carboxyl group-containing monomer.

As the carboxyl group-containing monomer, a monomer containing a carboxyl group and a polymerizable double bond can be suitably used. Such monomers include acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, and the like. These carboxyl group-containing monomers may be used singly or in combination of two or more.

When the (meth)acrylic polymer contains a structural unit derived from a carboxyl group-containing monomer, the proportion of the structural unit derived from the carboxyl group-containing monomer to the total structural units of the (meth)acrylic polymer is limited to this. Although it is not limited, it is preferably 0.1 to 10% by weight, more preferably 0.2 to 8% by weight, even more preferably 0.3 to 7% by weight, particularly preferably 0. It is 5 to 5% by weight. It is preferable that the proportion of the structural units derived from the carboxyl group-containing monomer to the total structural units of the (meth)acrylic polymer is 0.1% by weight or more because the cohesiveness of the adhesive is improved. Further, it is preferable that the ratio is 10% by weight or less, since the wettability to the adherend is improved.

The structural unit derived from the hydroxyl group-containing monomer can be introduced into the (meth)acrylic polymer by, for example, polymerizing the hydroxyl group-containing monomer.

As the hydroxyl group-containing monomer, a monomer containing a hydroxyl group and a polymerizable double bond can be suitably used. Such monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, Hydroxyalkyl (meth)acrylates such as 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate; vinyl alcohol, allyl alcohol, caprolactone-modified 2-hydroxyethyl Crosslinkable monomers containing alcoholic hydroxyl groups such as (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, and 2-acryloyloxyethyl-2-hydroxyethylphthalic acid; diethylene glycol (meth)acrylate and oxyalkylene-modified monomers such as polyethylene glycol (meth)acrylate; and the like. These hydroxyl group-containing monomers may be used alone or in combination of two or more.

Among these, the hydroxyl group-containing monomer is preferably a hydroxyalkyl (meth)acrylate in which the hydroxyalkyl alkyl has 2 to 8 carbon atoms, from the viewpoint of reactivity with the crosslinking agent.

When the (meth)acrylic polymer contains a structural unit derived from a hydroxyl group-containing monomer, the proportion of the structural unit derived from the hydroxyl group-containing monomer to the total structural units of the (meth)acrylic polymer is limited to this. The amount is preferably 0.01 to 5.0% by weight, more preferably 0.05 to 4.0% by weight, even more preferably 0.07 to 3.0% by weight, especially Preferably it is 0.1 to 2.0% by weight. It is preferable that the proportion of the structural units derived from the hydroxyl group-containing monomer to the total structural units of the (meth)acrylic polymer be 0.01% by weight or more, since it behaves as a crosslinking point. Further, it is preferable that the ratio is 5.0% by weight or less because the adhesive strength is improved.

Alternatively, the (meth)acrylic polymer has a structural unit derived from the acrylic acid alkoxyalkyl ester monomer in a proportion of 50 to 99.5% by weight based on the total structural units of the (meth)acrylic polymer. , the proportion of structural units derived from carboxyl group-containing monomers is 0.1 to 10% by weight, and the proportion of structural units derived from hydroxyl group-containing monomers is 0.01 to 0.5% by weight, which may be an acrylic polymer. .

The (meth)acrylic polymer of the present invention may contain structural units derived from other monomers as long as the effects of the present invention are not impaired.

The structural unit derived from the other monomer is preferably a structure formed by polymerizing the other monomer, but if it has the same structure as the structure formed by polymerizing the other monomer, the structural unit derived from the other monomer may be used. It may be formed by a method other than the method of polymerizing.

The other monomers are not particularly limited, and monomers normally used in (meth)acrylic pressure-sensitive adhesives, such as alkyl (meth)acrylic esters, can be used. The alkyl group of the alkyl (meth)acrylic acid ester is preferably an alkyl group having 1 to 20 carbon atoms. Moreover, the alkyl group may be any of a straight chain, a branched chain, and an alicyclic alkyl group.

Specific examples of alkyl (meth)acrylates 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 include isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, and cyclododecyl (meth)acrylate. These alkyl (meth)acrylic esters may be used alone or in combination of two or more. The proportion of structural units derived from alkyl (meth)acrylic esters in all structural units of the (meth)acrylic polymer is preferably 45% by weight or less, more preferably 40% by weight or less.

Furthermore, as the other monomer, a vinyl compound can be used in addition to the alkyl (meth)acrylic acid ester. Examples of the vinyl compounds include aromatic unsaturated hydrocarbon compounds such as styrene and α-methylstyrene; vinyl esters of monocarboxylic acids having 1 to 5 carbon atoms such as vinyl acetate and vinyl propionate; dimethyl (meth)acrylamide; Examples include diethyl (meth)acrylamide, isopropyl (meth)acrylamide, (meth)acryloylmorpholine, N-vinylpyrrolidone, and (meth)acrylonitrile. These vinyl compounds may be used alone or in combination of two or more. The ratio of the structural units derived from the vinyl compound to the total structural units of the (meth)acrylic polymer is preferably 20% by weight or less, more preferably 10% by weight or less.

In one embodiment of the present invention, the weight average molecular weight of the (meth)acrylic polymer is preferably 100,000 to 2,000,000, more preferably 200,000 to 1,500,000. It is preferable that the weight average molecular weight is 100,000 or more from the viewpoint of adhesion of the formed coating film. It is preferable that the weight average molecular weight is 2,000,000 or less because it allows good dispersion in a solvent. Here, in this specification, the weight average molecular weight is a polystyrene equivalent molecular weight measured using gel permeation chromatography (GPC). More specifically, the weight average molecular weight was determined using a measuring device manufactured by Tosoh Corporation, product number: HLC-8220GPC, a separation column manufactured by Tosoh Corporation, product number: TSKgel Super HZM-M, and a standard The value can be calculated using polystyrene (manufactured by Tosoh Corporation).

For acrylic polymers for which it is not appropriate to measure under the above conditions, the weight average molecular weight may be measured, for example, with appropriate minimum changes to the above conditions.

In one embodiment of the present invention, the glass transition temperature of the acrylic polymer is preferably −100° C. to −100° C. from the viewpoint of adhesiveness, tackiness, etc. of the adhesive composition and the adhesive composition for concrete curing adhesive tape. The temperature may be 10°C, more preferably -90°C to -20°C, even more preferably -80°C to -30°C.

The glass transition temperature of an acrylic polymer is determined by the formula:
1/Tg=Σ(Wm/Tgm)/100
(In the formula, Tg is the glass transition temperature (absolute temperature: K) of the polymer, Wm is the content (% by weight) of monomer m in the monomer components constituting the polymer, and Tgm is the content of monomer m in the monomer components constituting the polymer. Glass transition temperature (absolute temperature: K) of homopolymer)
The temperature may be determined based on Fox's equation expressed as follows.

In addition, for monomers whose glass transition temperature is unknown, such as special monomers and polyfunctional monomers, the glass transition temperature can be determined using only monomers whose glass transition temperature is known. good.

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

The glass transition temperature of the acrylic polymer can be easily adjusted by appropriately adjusting the type and amount of raw material monomers used in preparing the acrylic polymer.

The content of the (meth)acrylic polymer contained in the adhesive composition for concrete curing adhesive tape according to one embodiment of the present invention is preferably based on the total weight of the adhesive composition for concrete curing adhesive tape. The amount is 20 to 80% by weight, more preferably 25 to 70% by weight, and even more preferably 30 to 60% by weight.

When the content of the (meth)acrylic polymer is 20% by weight or more, it is possible to realize a concrete curing adhesive tape that has excellent adhesion to wet concrete surfaces and excellent removability.

(Method for producing (meth)acrylic polymer)
As a method for producing the (meth)acrylic polymer, a method of polymerizing monomers by a conventionally known polymerization method can be employed, and the polymerization method is not particularly limited. For example, a solution polymerization method or a bulk polymerization method can be used, and the solution polymerization method is preferred from an industrial perspective. This is because the solution polymerization method allows easy removal of polymerization heat during polymerization and has good operability.

In the solution polymerization method or bulk polymerization method, there are various methods, such as a method in which monomer components are polymerized by charging them all at once, a method in which the monomer components are polymerized while being dropped, and a method in which a portion is charged in bulk and the remaining monomer is polymerized while being dropped. can also be adopted.

Examples of the polymerization initiator include methyl ethyl ketone peroxide, benzoyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxyoctoate, t-butyl peroxybenzoate, lauroyl peroxide, etc. Known initiators such as peroxide polymerization initiators containing , or azo polymerization initiators containing azobisisobutyronitrile and the like can be used. The polymerization initiator is preferably used in an amount of 0.01 to 1% by weight based on the weight of the monomer in the polymerization reaction vessel before post-addition.

Examples of solvents used in solution polymerization include aromatic hydrocarbons such as toluene and xylene; aliphatic esters such as ethyl acetate and butyl acetate; alicyclic hydrocarbons such as cyclohexane; and fatty acids such as hexane and pentane. Examples include group hydrocarbons, but there are no particular limitations as long as they do not inhibit the above polymerization reaction. These solvents may be used alone or in a mixture of two or more. Note that the amount of solvent to be used may be determined as appropriate.

In addition, when the manufacturing method of the (meth)acrylic polymer is solution polymerization, the mixture containing the solvent and the (meth)acrylic polymer obtained by the manufacturing method can also be used as the adhesive composition and concrete curing adhesive of the present invention. It can be used as an adhesive composition for tape. Therefore, such adhesive compositions and adhesive compositions for concrete curing adhesive tapes are also included in the adhesive compositions and adhesive compositions for concrete curing adhesive tapes according to one embodiment of the present invention.

The content of (meth)acrylic polymer in such adhesive compositions and adhesive compositions for concrete curing adhesive tapes is 10% by weight based on the entire adhesive composition or the entire adhesive composition for concrete curing adhesive tapes. % or more, preferably 20% by weight or more, more preferably 30% by weight or more, and 80% by weight or less (for example, 70% by weight or less, 60% by weight or less).

Reaction conditions such as reaction temperature and reaction time may be conveniently set according to, for example, the composition of the monomer components, the polymerization method, the required characteristics of the resulting adhesive composition, the use of the adhesive, etc., and are not particularly limited. . Further, the reaction pressure is not particularly limited, and may be normal pressure (atmospheric pressure), reduced pressure, or increased pressure. Note that the polymerization reaction is preferably performed in an atmosphere of an inert gas such as nitrogen gas.

[1.2 Other ingredients]
(1.2.1 Crosslinking agent)
The adhesive composition for a concrete curing adhesive tape according to an embodiment of the present invention may further contain a crosslinking agent in addition to the (meth)acrylic polymer. As the crosslinking agent, a compound capable of reacting with at least one selected from carboxyl groups and hydroxyl groups contained in the (meth)acrylic polymer can be suitably used. Examples of crosslinking agents that can react with hydroxyl groups include isocyanate crosslinking agents, epoxy crosslinking agents, metal chelate crosslinking agents, and the like. Examples of crosslinking agents that can react with carboxyl groups include oxazoline crosslinking agents, carbodiimide crosslinking agents, and epoxy crosslinking agents.

As the isocyanate-based crosslinking agent, polyfunctional isocyanate (polyisocyanate) is more preferable. A polyfunctional isocyanate is a compound containing at least two isocyanate groups per molecule. Preferred examples of the isocyanate-based crosslinking agent include diisocyanates such as aromatic diisocyanates, alicyclic diisocyanates, and aliphatic diisocyanates; adduct polyisocyanate compounds; bullet polyisocyanate compounds; and polyisocyanate compounds having an isocyanurate ring.

More specific examples of the aromatic diisocyanate include tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate, and polymethylene polyphenylisocyanate.

More specific examples of the aliphatic diisocyanate include butane diisocyanate, pentane diisocyanate, hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate, lysine diisocyanate, butylene diisocyanate, and the like.

More specific examples of the alicyclic diisocyanate include hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,4-cyclohexane diisocyanate, cyclopentylene diisocyanate, isophorone diisocyanate, and the like.

Examples of the adduct polyisocyanate compound include commercial products such as "Sumidur L" (manufactured by Sumitomo Bayer Urethane Co., Ltd.); "Coronate L" and "Coronate HL" (both manufactured by Nippon Polyurethane Co., Ltd.).

More specifically, examples of the burette polyisocyanate compound include commercially available products such as "Sumidur N" (manufactured by Sumitomo Bayer Urethane).

More specifically, examples of the polyisocyanate compound having an isocyanurate ring include "Desmodur IL" and "Desmodur HL" (both manufactured by Bayer AG); "Coronate EH" and "Coronate Examples include commercially available products such as "HX" (both manufactured by Nippon Polyurethane Industries, Ltd.); "Takenate D110N" and "Takenate D120N" (both manufactured by Mitsui Chemicals).

These can be used alone or in combination of two or more. Furthermore, so-called blocked isocyanates, which are obtained by inactivating the isocyanate groups of these compounds by reacting with a masking agent having active hydrogen, can also be used.

Examples of the epoxy crosslinking agent include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A type epoxy resin, N,N,N',N'-tetraglycidyl -m-xylene diamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N-diglycidylaniline, N,N-diglycidyltoluidine and the like.

The commercially available epoxy crosslinking agents include Denacol EX-832 (manufactured by Nagase Chemical Industries, Ltd.), Denacol EX-841 (manufactured by Nagase Chemical Industries, Ltd.), Tetrad C (manufactured by Mitsubishi Gas Chemical Co., Ltd.), Tetrad X (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and the like can be suitably used.

Examples of the metal chelate crosslinking agent include acetylacetone, methyl acetoacetate, etc. for metals such as aluminum, zinc, cadmium, nickel, cobalt, copper, calcium, barium, titanium, manganese, iron, lead, zirconium, chromium, and tin. Examples include metal chelate compounds coordinated with ethyl acetoacetate, ethyl lactate, methyl salicylate, and the like.

The oxazoline crosslinking agent is not particularly limited as long as it is a compound having at least two or more oxazoline groups in its molecule. For example, 2,2'-bis(2-oxazoline), 2,2'-ethylene-bis(4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis(2-oxazoline) , compounds having an oxazoline group such as bis(2-oxazolinylcyclohexane) sulfide, and oxazoline group-containing polymers. One type or two or more types of these can be used. Among these, oxazoline group-containing polymers are preferred for ease of handling.

Oxazoline group-containing polymers are generally obtained by polymerizing addition-polymerizable oxazolines such as 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, and 2-isopropenyl-2-oxazoline. Other monomers may be copolymerized with the oxazoline group-containing polymer as necessary. The method for polymerizing the oxazoline group-containing polymer is not particularly limited, and any known polymerization method can be employed.

Commercial products of the oxazoline crosslinking agent include the Epocross (registered trademark) series manufactured by Nippon Shokubai Co., Ltd., such as water-soluble types "WS-500" and "WS-700"; emulsion type "K- 1010E,” “K-1020E,” “K-1030E,” “K-2010E,” “K-2020E,” and “K-2030E.”

The carbodiimide crosslinking agent is not particularly limited as long as it is a compound having at least two or more carbodiimide groups in its molecule. For example, compounds having a carbodiimide group such as p-phenylene-bis(2,6-xylylcarbodiimide), tetramethylene-bis(t-butylcarbodiimide), and cyclohexane-1,4-bis(methylene-t-butylcarbodiimide) and polycarbodiimide, which is a polymer having carbodiimide groups. One type or two or more types of these can be used. Among these, polycarbodiimide is preferred because of its ease of handling.

Commercially available polycarbodiimides include the Carbodilite (registered trademark) series manufactured by Nisshinbo. Specific products include, for example, water-soluble types “SV-02”, “V-02”, “V-02-L2”, and “V-04”; emulsion types “E-01” and “E Examples include "V-02"; organic solution type "V-01", "V-03", "V-07", and "V-09"; and solvent-free type "V-05".

The adhesive composition for a concrete curing adhesive tape according to an embodiment of the present invention may contain one or more types of the above-mentioned crosslinking agent.

The content of the crosslinking agent contained in the adhesive composition for concrete curing adhesive tape according to one embodiment of the present invention is preferably 0.01 to 5% by weight, more preferably 0.01 to 5% by weight based on the (meth)acrylic polymer. Preferably it is 0.3 to 3% by weight. When the content of the crosslinking agent is 0.01% by weight or more based on the acrylic polymer, the acrylic polymer is sufficiently crosslinked. Moreover, if it is 5% by weight or less, it is possible to avoid a decrease in adhesiveness due to the crosslinking reaction proceeding more than desired.

(1.2.2 Lactam polymer)
The adhesive composition for concrete curing adhesive tape according to one embodiment of the present invention may contain a lactam polymer.

In one embodiment of the present invention, the lactam polymer may contain at least a structural unit derived from a lactam monomer. A structural unit derived from a lactam monomer can be introduced into the lactam polymer by polymerizing a monomer component containing the lactam monomer.

Examples of the lactam monomer include vinyl lactam monomers such as N-vinyl lactam (eg, N-vinylpyrrolidone, N-vinylcaprolactam).

A typical lactam monomer is N-vinylpyrrolidone. When the structural unit derived from the lactam monomer includes a structural unit derived from N-vinylpyrrolidone, the proportion of the structural unit derived from N-vinylpyrrolidone to the structural unit derived from the lactam monomer is, for example, 10% by weight or more (for example, (15 to 100% by weight), preferably 20% by weight or more, 25% by weight or more, more preferably 30% by weight or more, 40% by weight or more, particularly preferably 50% by weight or more, and 60% by weight or more, It may be 70% by weight or more, 80% by weight or more, 90% by weight or more, or 100% by weight (substantially only N-vinylpyrrolidone).

The ratio of the structural units derived from the lactam monomer to the total structural units of the lactam polymer is, but is not limited to, for example, 10% by weight or more (for example, 15 to 100% by weight), more preferably is 20% by weight or more, 25% by weight or more, more preferably 30% by weight or more, 40% by weight or more, particularly preferably 50% by weight or more, 60% by weight or more, 70% by weight or more, 80% by weight or more, 90% by weight or more. It may be at least 95% by weight, or at least 100% by weight (substantially only the lactam monomer).

In one embodiment of the present invention, the lactam-based polymer may be hydrophilic (hydrophilic lactam-based polymer) or water-absorbent (lactam-based polymer used as a water-absorbing material). In such a hydrophilic or water-absorbing lactam polymer, the monomer component preferably contains a hydrophilic lactam monomer, and preferably contains a lactam monomer that is easily soluble in water in an atmosphere of 23°C. It is more preferable to include (preferably a water-soluble lactam polymer). For example, the proportion of the structural units derived from the hydrophilic lactam monomer to the total structural units of the lactam polymer may be the above proportion (for example, 50% by weight or more).

Further, in an embodiment of the present invention, the proportion of structural units derived from N-vinylpyrrolidone in all structural units of the lactam polymer is preferably 50% by weight or more, 60% by weight or more, or 70% by weight or more. , 80% by weight or more, 90% by weight or more, 95% by weight or more, or 100% by weight (substantially only N-vinylpyrrolidone).

In one embodiment of the present invention, the lactam polymer may contain, in addition to the structural unit derived from the lactam monomer, a structural unit derived from a monomer other than the structural unit derived from the lactam monomer.

Examples of the other monomers include the monomers exemplified as the monomers for the (meth)acrylic polymer.

In one embodiment of the present invention, the lactam polymer includes, for example, an acid group (carboxyl group, etc.), an isocyanate group, an oxazoline group, an oxazolidine group, a hydrazino group, an epoxy group, an amino group, a hydroxyl group, a mercapto group, etc. may contain a structural unit derived from a monomer having a functional group. Since the lactam polymer has a structural unit derived from a monomer having such a functional group, the type of crosslinking agent (combination with the functional group possessed by the crosslinking agent) and the functional group possessed by the (meth)acrylic polymer can be controlled. Depending on the type, etc., it is easy to form a crosslinked structure efficiently.

Further, the functional group may be a functional group that can react with at least a functional group of a crosslinking agent (crosslinking reaction).

Further, the functional group may be a functional group capable of reacting (crosslinking reaction) with a functional group included in the acrylic polymer.

Specific examples of the monomer having the functional group include acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, and the like.

When the lactam polymer contains, in addition to the structural unit derived from the lactam monomer, a structural unit derived from a monomer other than the structural unit derived from the lactam monomer, The proportion of structural units derived from other monomers is preferably 50% by weight or less, more preferably 40% by weight or less, 30% by weight or less, 25% by weight or less, 20% by weight or less, 15% by weight or less, More preferably, it is 10% by weight or less, 8% by weight or less, 5% by weight or less, 3% by weight or less, 2% by weight or less, and 1% by weight or less.

When the lactam polymer is a copolymer, the structure of the copolymer is not particularly limited, and may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

The weight average molecular weight of the lactam polymer may be selected from the range of 300 or more, 500 or more, 1000 or more, preferably 2000 or more, more preferably 3000 or more, 5000 or more, 10,000 or more. The number may be 20,000 or more, 30,000 or more, 50,000 or more, or 80,000 or more.

The upper limit of the weight average molecular weight of the lactam polymer is not particularly limited, and is, for example, 3 million, 2.5 million, 2 million, 1.5 million, 1.3 million, 1.1 million, 1 million, 900,000, 800,000, 700,000, It may be 600,000, 500,000, 400,000, 300,000, 200,000, etc.

Such a weight average molecular weight is advantageous in terms of appropriate viscosity (and therefore good coating properties), compatibility with (meth)acrylic polymers, and the like.

The lactam polymer may be a commercially available product or a synthesized product. The method for synthesizing the lactam polymer is not particularly limited, and the monomer components may be polymerized by a conventional method. In the polymerization, conventional polymerization initiators, chain transfer agents, etc. may be used. In addition, polymerization conditions (type and amount of solvent, temperature, atmosphere, time, etc.) can be selected as appropriate.

The content of the lactam polymer contained in the adhesive composition for a concrete curing adhesive tape according to an embodiment of the present invention is, for example, 0.1% by weight based on the amount of the (meth)acrylic polymer. It may be selected from the above range, and is 0.2% by weight or more, 0.25% by weight or more, preferably 0.3% by weight or more, 0.35% by weight or more, and more preferably 0.4% by weight or more. , 0.45% by weight or more, 0.5% by weight or more, 0.55% by weight or more, 0.6% by weight or more, 0.65% by weight or more, 0.7% by weight or more, 0. 75% by weight or more, 0.8% by weight or more, 0.85% by weight or more, 0.9% by weight or more, 0.95% by weight or more, 1% by weight or more, 1.05% by weight or more, 1.1% by weight 1.15% by weight or more, 1.2% by weight or more, 1.25% by weight or more, 1.3% by weight or more, 1.35% by weight or more, 1.4% by weight or more, 1.5% by weight or more , 1.6% by weight or more, 1.7% by weight or more, 1.8% by weight or more, 1.9% by weight or more, 2% by weight or more, for example, 2.5% by weight or more, 3% by weight % or more, 4 weight % or more, 5 weight % or more, 6 weight % or more, 7 weight % or more, 8 weight % or more, or 9 weight % or more. The upper limit of the content of the lactam polymer relative to the amount of the acrylic polymer is not particularly limited, but for example, 99% by weight, 95% by weight, 90% by weight, 85% by weight, 80% by weight, 75% by weight, 70% by weight, 65% by weight, 60% by weight, 55% by weight, 50% by weight, 45% by weight, 40% by weight, 35% by weight, 30% by weight, 28% by weight, 25% by weight, 22% by weight, 20% by weight %, 18% by weight, 16% by weight, etc.

If the content of the lactam-based polymer is 0.1% by weight or more with respect to the amount of the (meth)acrylic polymer, the concrete curing adhesive tape obtained from the adhesive composition for concrete curing adhesive tape is , is preferable because it can further improve the adhesion to the wet concrete surface. Further, it is preferable that the content of the lactam polymer is 99% by weight or less based on the amount of the (meth)acrylic polymer, since the wettability to the adherend is improved.

(1.2.3 Organic solvent)
The adhesive composition for concrete curing adhesive tape according to one embodiment of the present invention may contain an organic solvent.

The boiling point (boiling point at normal pressure to atmospheric pressure) of the organic solvent is not particularly limited, but from the viewpoint of forming an adhesive layer, it should be a relatively low boiling point, for example, 180°C or lower, more preferably 150°C or lower, and Preferably, the temperature may be 130°C or lower.

The organic solvent may include an organic solvent (sometimes referred to as organic solvent A) that can dissolve the lactam polymer. The organic solvent A may be a hydrophilic or water-soluble solvent, depending on the type of the lactam polymer. The solubility of organic solvent A in water (20°C) may be, for example, 10 g/100 g or more, preferably 20 g/100 g or more, more preferably 50 g/100 g or more, and is a solvent that is miscible (optionally miscible) with water. (a good solvent for water).

The organic solvent may include an organic solvent (sometimes referred to as organic solvent B) that can dissolve the (meth)acrylic polymer. The organic solvent B may be a hydrophobic solvent, although it depends on the type of (meth)acrylic polymer. The organic solvent B may be a solvent whose solubility in water (at 20° C.) is, for example, 10 g/100 g or less, or, for example, less than 10 g/100 g, and may be a solvent that does not substantially dissolve in water ( (poor solvent).

Organic solvent B may be the same solvent as organic solvent A, that is, an organic solvent that can dissolve both the lactam polymer and the (meth)acrylic polymer, but usually does not dissolve the lactam polymer. (or difficult to dissolve) solvent (or poor solvent for lactam-based polymers).

Organic solvent B may be soluble in organic solvent A (a good solvent for organic solvent A). By combining such organic solvents B and A, (meth)acrylic polymers (e.g., hydrophobic (meth)acrylic polymers) and lactam polymers (e.g., hydrophilic lactam polymers) can be efficiently mixed. It is easy to mix uniformly, and it is easy to efficiently realize these compatibility (and transparency) in the adhesive layer.

Examples of the organic solvent A include alcohols (e.g., methanol, ethanol, isopropanol, ethylene glycol, glycerin, etc.), halogen-based solvents (e.g., chloroform, etc.), and amides, although it depends on the type of lactam polymer. Examples include linear amides (eg, N,N-dimethylformamide), cyclic amides (or lactams, such as 2-pyrrolidone), and the like. Examples of organic solvent B include aromatic hydrocarbons (e.g., toluene, xylene, etc.), aliphatic esters (e.g., ethyl acetate, etc.), although it depends on the type of (meth)acrylic polymer. butyl acetate, etc.). Organic solvent A and organic solvent B may be used alone or in combination of two or more. In the present invention, by selecting the type of organic solvent (as well as the combination thereof and the form of existence of each component in the composition) as described above, it is easy to efficiently exhibit adhesiveness to a wet surface.

In the adhesive composition for a concrete curing adhesive tape according to an embodiment of the present invention, at least the lactam polymer, more preferably the lactam polymer and the (meth)acrylic polymer are dissolved in a solvent. preferable. By having the lactam polymer (and the (meth)acrylic polymer) present in a dissolved state, it is easy to exhibit excellent coating properties and adhesion to the concrete surface in a wet state.

When the organic solvent includes organic solvent B and organic solvent A, the ratio of these is organic solvent B/organic solvent A (weight ratio) = 99.9/0.1 to 1/99 (for example, 99. 5/0.5 to 5/95), preferably 99/1 to 10/90 (for example, 98.5/1.5 to 15/85), more preferably 98/2 to 20/80 (for example, 97 .5/2.5 to 25/75), especially about 97/3 to 30/70 (for example, 96.5/3.5 to 40/60), 99/1 to 50/50, It may be 99/1 to 55/45, 98/2 to 60/40, 97/3 to 65/35, 96/4 to 70/30 (for example, 95/5 to 80/20), etc.

The adhesive composition for concrete curing adhesive tape according to one embodiment of the present invention may contain volatile components such as the organic solvent, but the content of non-volatile components excluding such volatile components is as follows: The amount is preferably 20 to 80% by weight, more preferably 25 to 70% by weight, and even more preferably 30 to 60% by weight, based on the total weight of the adhesive composition for use.

(1.2.4 Other ingredients other than the above)
The adhesive composition for a concrete curing adhesive tape according to an embodiment of the present invention may further contain other components commonly used in adhesives, as necessary, to the extent that the effects of the present invention are not impaired. Good too. Such other ingredients include fillers, pigments, diluents, anti-aging agents, UV absorbers, UV stabilizers, viscosity modifiers, plasticizers, softeners, surfactants, leveling agents, antioxidants, and photostabilizers. agent, antifoaming agent, release modifier, etc. These additives can be used alone or in combination of two or more. The content of these additives may be appropriately set depending on the type of the component, intended use, etc. so that desired physical properties can be obtained.

[1.3 Method for producing adhesive composition for concrete curing adhesive tape]
An adhesive composition for a concrete curing adhesive tape according to an embodiment of the present invention includes the (meth)acrylic polymer, which is mixed with any other component selected from other components other than the (meth)acrylic polymer. It can be manufactured by

The mixing method is not particularly limited, but it is desirable that each component is uniformly dispersed.

Here, the order in which the above-mentioned components are mixed is not particularly limited and may be in any order. When the (meth)acrylic polymer, the lactam polymer, and the organic solvent A are mixed with one selected from the organic solvent B and the other components as necessary, the lactam polymer is mixed in advance. After dissolving in the organic solvent A, it is preferable to mix it with other components. By dissolving the lactam polymer in the organic solvent A in advance, the (meth)acrylic polymer and the lactam polymer can be mixed (compatible) relatively uniformly.

[2 Adhesive layer, adhesive product]
The adhesive product according to one embodiment of the present invention includes an adhesive layer formed by applying and drying the adhesive composition for concrete curing adhesive tape according to one embodiment of the present invention. Examples of such adhesive products include adhesive sheets, adhesive labels, adhesive tapes, double-sided tapes, and the like. Such adhesive products are manufactured without a substrate or by forming an adhesive layer on a substrate. More specifically, for example, adhesive tape for concrete curing is used to fix curing sheets such as polyethylene, polypropylene, polyethylene terephthalate, and nonwoven fabric on the concrete surface, or masking tape (curing tape for concrete) is used to protect concrete. ) etc. are listed as adhesive products.

Examples of the base material include conventionally known papers such as high-quality paper, kraft paper, crepe paper, and glassine paper; plastics such as polyethylene, polypropylene, polyester, polystyrene, polyethylene terephthalate, polyvinyl chloride, and cellophane; woven fabrics, nonwoven fabrics, etc. textile products etc. can be used. The shape of the base material may be, for example, a film, a sheet, a tape, a plate, a foam, etc., but is not particularly limited. An adhesive product can be obtained by applying the adhesive composition for concrete curing adhesive tape to one side of the base material by a known method. In addition, by applying the adhesive composition for concrete curing tape to a release paper, etc., which is a sheet-like material such as paper, synthetic paper, or plastic film coated with a release agent, it is possible to create a base material-less (single-layer structure) adhesive composition for concrete curing tape. ), which can be used as a double-sided tape without a base material. Alternatively, a double-sided tape may be obtained by applying the same or different adhesive compositions for concrete curing tape to both sides of the base material.

The method for applying the adhesive composition for concrete curing adhesive tape to the substrate is not particularly limited, and known methods such as roll coating, spray coating, dipping, etc. can be employed. In this case, it is possible to adopt either a method of applying the adhesive composition for concrete curing adhesive tape directly to the base material, or a method of applying the adhesive composition to release paper, etc., and then transferring the applied material onto the base material. It is.

After applying the adhesive composition for concrete curing adhesive tape, it is dried to form an adhesive layer on the base material. The drying temperature is not particularly limited, but if a crosslinking agent is included, the crosslinking reaction will proceed during heat drying, so it is preferable to dry at a temperature at which the crosslinking reaction proceeds quickly depending on the type of crosslinking agent. Depending on the application, the adhesive composition for concrete curing adhesive tape may be applied directly to the adherend.

The drying temperature during the drying is not particularly limited, but is preferably a temperature at which the solvent in the composition is sufficiently volatilized.

For example, release paper may be attached to the surface of the adhesive layer formed on the base material. Release paper is also called release paper. Thereby, the surface of the adhesive layer can be suitably protected and preserved. The release paper is peeled off from the surface of the adhesive composition for concrete curing adhesive tape when using the adhesive product. In addition, when an adhesive surface is formed on one side of a base material such as a sheet or tape shape, it is preferable to apply a known mold release agent to the back side of this base material to form a mold release agent layer. . As a result, if the adhesive sheet (tape) is rolled into a roll with the adhesive layer inside, the adhesive layer will come into contact with the release agent layer on the back of the base material, so the surface of the adhesive layer will be protected and preserved.

In this specification, concrete curing adhesive tape refers to an adhesive tape used for curing concrete surfaces. A typical example of a concrete curing adhesive tape is, for example, used to fix a curing sheet to a concrete surface in a method of curing the concrete surface by covering it with a curing sheet to keep it moist. Adhesive tape (adhesive tape for concrete curing) can be mentioned. Alternatively, as another example, an adhesive tape (adhesive tape for concrete protection) used for the purpose of protecting concrete curbs, etc. when performing construction work to pave roads with asphalt, etc., can also be used with the concrete of the present invention. Included in curing adhesive tape. However, the concrete curing adhesive tape is not limited to this, and any adhesive tape used for concrete curing may be used.

EXAMPLES Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples. In addition, in the following examples, "part" means "part by weight".

〔Measuring method〕
The adhesiveness of the adhesive tapes obtained in Examples 1 to 9 and Comparative Examples 1 and 2 to dry concrete surfaces and wet concrete surfaces, and the removability to dry concrete surfaces and wet concrete surfaces were evaluated by the following method. evaluated.

(1) Method for evaluating adhesion to dry concrete surface A rectangular adhesive tape was prepared by cutting the adhesive tape into a rectangle with a length of 50 mm and a width of 25 mm. As the adherend, a mortar plate compliant with JIS standard K5600 was prepared. The mortar plate used had its surface polished with sandpaper having a grain size of 150. Peel off the release paper of the rectangular adhesive tape, place the rectangular adhesive tape on the mortar surface so that the adhesive side is in contact with the mortar surface, and place a roll with a mass of 2 kg on the rectangular adhesive tape on the mortar surface. The rectangular adhesive tape was pasted onto the mortar surface by moving it back and forth over the molded adhesive tape. After standing for 25 minutes at room temperature (approximately 23°C), the peeling force (adhesive force) when the rectangular adhesive tape was peeled off at a peeling angle of 180° and a peeling speed of 300 mm/min was measured, and the peeling force (adhesive force) was measured on the dry concrete surface. The adhesion to was evaluated.

(2) Method for evaluating adhesion to wet concrete surfaces A mortar board similar to that in (1) above was immersed in water for 24 hours, then taken out, the water on the surface of the mortar board was gently wiped back and forth with a cloth, and the wet concrete surface was removed. It was worn as a body. Thereafter, measurements were performed in the same manner as in (1) above to evaluate the adhesion to the wet concrete surface.

(3) Evaluation of re-peelability on dry concrete surface and wet concrete surface In (1) and (2) above, after measuring the peeling force on dry concrete surface and wet concrete surface, respectively, the mortar surface after peeling was visually observed. The state of adhesive residue was observed and evaluated according to the criteria shown below.
○: No adhesive residue ×: Adhesive residue on part or the entire surface of the pasting mark [Example 1]
In a reaction vessel equipped with a cooling tube, a nitrogen gas introduction tube, a thermometer, a dropping funnel, and a stirrer, 150 parts of ethyl acetate (parts by weight, same hereinafter), 94.9 parts of 2-methoxyethyl acrylate (AME), 5.0 parts of acrylic acid (AA) and 0.1 part of 2-hydroxyethyl acrylate (HEA) were charged (composition 1 in Table 1). Thereafter, 0.1 part of an azo polymerization initiator (trade name: ABN-E, manufactured by Nippon Finechem Co., Ltd.) was added to the reaction vessel, and the weight was reduced by reacting at 80°C for 6 hours in a nitrogen gas atmosphere. An acrylic polymer having an average molecular weight of 600,000 was obtained. The resulting reaction mixture containing the acrylic polymer was cooled to room temperature to obtain adhesive composition A. Adhesive composition B was prepared by adding 0.021 parts of Tetrad C (manufactured by Mitsubishi Gas Chemical Co., Ltd.) (0.0525% by weight based on the solid content of the acrylic polymer) to 100 parts of adhesive composition A. Obtained. The adhesive composition B 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, an adhesive layer having a thickness of 25 μm was formed on the release paper. A PET (polyethylene terephthalate) film base material (thickness: 25 μm) was bonded onto this adhesive layer. Thereafter, aging was performed at 40° C. for 72 hours to obtain a pressure-sensitive adhesive tape whose one side was an adhesive surface.

[Example 2, 3]
An acrylic polymer, an adhesive composition, and an adhesive tape were obtained by performing the same reaction and operation as in Example 1, except that the type and amount of the crosslinking agent were changed as shown in Table 2.

[Example 4]
For 100 parts of the adhesive composition A obtained in Example 1, 20 parts of a methanol solution of polyvinylpyrrolidone (PVP, K-30 manufactured by Nippon Shokubai Co., Ltd.) (4 parts as PVP, acrylic polymer solid content as PVP) Adhesive composition B was obtained by adding Tetrad C (manufactured by Mitsubishi Gas Chemical Co., Ltd.) as shown in Table 2. An adhesive tape was obtained in the same manner as in Example 1 using the obtained adhesive composition B.

[Example 5]
To 100 parts of the adhesive composition A obtained in Example 1, 20 parts of isopropyl alcohol solution of polyvinylpyrrolidone (PVP, K-30 manufactured by Nippon Shokubai Co., Ltd.) (4 parts as PVP, acrylic polymer solid as PVP) Adhesive composition B was obtained by adding Tetrad C (manufactured by Mitsubishi Gas Chemical Co., Ltd.) as shown in Table 2. An adhesive tape was obtained in the same manner as in Example 1 using the obtained adhesive composition B.

[Comparative example 1]
An acrylic polymer, an adhesive composition, and an adhesive tape were obtained by performing the same reaction and operation as in Example 1, except that the monomer composition was changed to Composition 2 shown in Table 1.

[Comparative example 2]
An acrylic polymer, an adhesive composition, and an adhesive tape were obtained by performing the same reaction and operation as in Example 1, except that the monomer composition was changed to Composition 3 shown in Table 1.

The abbreviations in Table 1 indicate the following compounds, respectively.
BA: Butyl acrylate 2EHA: 2-ethylhexyl acrylate AME: 2-methoxyethyl acrylate VAC: Vinyl acetate AA: Acrylic acid HEA: 2-hydroxyethyl acrylate

The abbreviations in Table 2 represent the following compounds, respectively.
PVP: polyvinylpyrrolidone MeOH: methanol IPA: isopropyl alcohol In addition, in Table 2, the amount of crosslinking agent is the amount added to 100 parts of adhesive composition A, and the amount of PVP is the solid content in 100 parts of adhesive composition A. This is the amount added per minute.

From Examples 1 to 5, it was found that the structure contained a structural unit derived from an acrylic acid alkoxyalkyl ester monomer, a structural unit derived from a carboxyl group-containing monomer, and a structural unit derived from a hydroxyl group-containing monomer, represented by the general formula (1). It can be seen that the adhesive tape obtained from the adhesive composition for concrete curing adhesive tape containing a meth)acrylic polymer has excellent adhesion to the concrete surface in a dry state and a wet state, and also has excellent removability.

In addition, from a comparison between Example 1 and Example 4, and a comparison between Example 2 and Example 5, an adhesive composition for concrete curing adhesive tape containing a lactam polymer in addition to a (meth)acrylic polymer was found. It can be seen that the adhesive tape obtained from the product has improved adhesion to wet concrete surfaces compared to a tape that does not contain a lactam polymer.

[Examples 6 to 9]
The same reactions and operations as in Example 1 were carried out, except that the monomer composition was changed as shown in Table 3, and the type and amount of the crosslinking agent were changed as shown in Table 4. A composition and adhesive tape were obtained.

The abbreviations in Table 3 indicate the following compounds, respectively.
MTG-A: Methoxy-triethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd.)
MAA: methacrylic acid NVP: N-vinylpyrrolidone

From the results of Examples 1 to 9 and Comparative Examples 1 and 2, concrete curing containing a (meth)acrylic polymer containing a structural unit derived from an acrylic acid alkoxyalkyl ester monomer, represented by the above general formula (1). Adhesive tapes obtained from adhesive compositions for adhesive tapes have excellent adhesion to concrete surfaces in dry and wet conditions, and are reusable compared to tapes that do not contain the structural unit derived from the acrylic acid alkoxyalkyl ester monomer. It can be seen that it has excellent removability.

Similar to the results of Examples 1 to 5, the results of Examples 6 to 9 show that the structural unit derived from the acrylic acid alkoxyalkyl ester monomer represented by the above general formula (1) and the structure derived from the carboxyl group-containing monomer An adhesive tape obtained from an adhesive composition for a concrete curing adhesive tape containing a (meth)acrylic polymer containing a structural unit derived from a hydroxyl group-containing monomer has excellent adhesion to concrete surfaces in a dry state and a wet state. It can be seen that it has excellent removability as well as excellent removability.

INDUSTRIAL APPLICATION This invention can be utilized for the adhesive product for concrete curing.

Claims (7)

An adhesive composition for concrete curing adhesive tape containing a (meth)acrylic polymer and a lactam polymer,
The (meth)acrylic polymer has the following general formula (1)
(In general formula (1), X is an alkylene group having 2 to 4 carbon atoms, Y is an alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 to 10)
An adhesive composition for a concrete curing adhesive tape, which contains a structural unit derived from an acrylic acid alkoxyalkyl ester monomer. The adhesive composition for a concrete curing adhesive tape according to claim 1, wherein the (meth)acrylic polymer further contains a structural unit derived from a carboxyl group-containing monomer and/or a structural unit derived from a hydroxyl group-containing monomer. The adhesive composition for concrete curing adhesive tape according to claim 1 or 2, which contains a crosslinking agent. The (meth)acrylic polymer contains a structural unit derived from a hydroxyl group-containing monomer,
Concrete curing according to any one of claims 1 to 3, wherein the proportion of structural units derived from the hydroxyl group-containing monomer to the total structural units of the (meth)acrylic polymer is 0.01 to 5% by weight. Adhesive composition for adhesive tape. The (meth)acrylic polymer contains a structural unit derived from a carboxyl group-containing monomer,
The concrete according to any one of claims 1 to 4, wherein the proportion of structural units derived from the carboxyl group-containing monomer to all structural units of the (meth)acrylic polymer is 0.1 to 10% by weight. Adhesive composition for curing adhesive tape. An adhesive composition containing a (meth)acrylic polymer and a lactam polymer,
The (meth)acrylic polymer has the following general formula (1)
(In general formula (1), X is an alkylene group having 2 to 4 carbon atoms, Y is an alkyl group having 1 to 10 carbon atoms, and n is an integer of 1 to 10)
contains a structural unit derived from an acrylic acid alkoxyalkyl ester monomer, a structural unit derived from a carboxyl group-containing monomer, and a structural unit derived from a hydroxyl group-containing monomer, and all of the above (meth)acrylic polymer As a proportion of the structural units, the proportion of structural units derived from the acrylic acid alkoxyalkyl ester monomer is 50 to 99.5% by weight, and the proportion of structural units derived from the carboxyl group-containing monomer is 0.1 to 10% by weight. A pressure- sensitive adhesive composition which is a (meth)acrylic polymer in which the proportion of structural units derived from a hydroxyl group-containing monomer is 0.01 to 0.5% by weight. The adhesive composition according to claim 6 , which is an adhesive composition for wet surfaces.