JP7009073B2 - Adhesive body - Google Patents

Description

The present invention relates to an adhesive body.

An adhesive film having a removable adhesive layer (removable adhesive film) is easy to handle and is used for various labels, lid materials, and the like (see, for example, Patent Document 1).

However, the conventional re-peelable adhesive film has a problem that the adhesive is deteriorated by ultraviolet rays and adhesive residue is generated when the re-peelable adhesive film is peeled off from the adherend.
This is especially true for removable adhesives, which are applied as lids for packaging materials that contain liquid-impregnated wet wipes, because when the lid label is flipped outdoors, the adhesive layer is exposed to UV light. The occurrence of various problems was remarkable.

Japanese Unexamined Patent Publication No. 2014-224263

An object of the present invention is to provide a re-peelable adhesive body applied to a packaging material for storing a wet sheet impregnated with a liquid, which is less likely to generate adhesive residue when peeled from an adherend due to deterioration over time. It is in.

Such an object is achieved by the present invention described in the following (1) to ( 6 ).

（ただし、式（１）中、ｎは２以上の整数、ｍは１以上４以下の整数を示す。） (1) An adhesive material applied to a packaging material for storing a wet sheet impregnated with a liquid.
With the base material
It is provided with an adhesive, an ultraviolet absorber having a function of absorbing ultraviolet rays, and a removable adhesive layer containing an oil absorber.
The pressure-sensitive adhesive layer is a porous body and a porous body as the oil absorbent.
A sticky substance containing a polymer compound having a chemical structure represented by the following formula (1) .

(However, in equation (1), n is an integer of 2 or more, and m is an integer of 1 or more and 4 or less.)

(2) The adhesive according to (1) above, which comprises a compound having a conjugated unsaturated bond as the ultraviolet absorber.

(3) The adhesive according to (1) or (2) above, wherein the content of the ultraviolet absorber with respect to 100 parts by mass of the adhesive is 0.1 parts by mass or more and 10 parts by mass or less.

( 4 ) The adhesive according to any one of (1) to ( 3 ) above, wherein the content of the oil absorbent with respect to 100 parts by mass of the adhesive is 0.1 parts by mass or more and 50 parts by mass or less.

( 5 ) The adhesive according to any one of (1) to ( 4 ) above, wherein the pressure-sensitive adhesive contains a monomer having a saturated aliphatic hydrocarbon group having 5 or more carbon atoms as a constituent component.

( 6 ) The pressure-sensitive adhesive according to any one of (1) to ( 5 ) above, wherein the pressure-sensitive adhesive layer further contains a plasticizer having an alkylene group having 4 or more carbon atoms in the molecule.

According to the present invention, it is possible to provide a re-peelable adhesive body which is less likely to generate adhesive residue when peeled from an adherend due to deterioration over time.

It is a schematic vertical sectional view which shows 1st Embodiment of the adhesive body (adhesive film) of this invention. It is a schematic vertical sectional view which shows 1st Embodiment of the manufacturing method of the adhesive body (adhesive film) of this invention. It is a perspective view which shows the preferable embodiment of the package (packaging material). FIG. 3 is a cross-sectional side view of the package (packaging material) shown in FIG. 3 in a closed state. FIG. 3 is a cross-sectional side view of the package (packaging material) shown in FIG. 3 in an open state.

Hereinafter, preferred embodiments of the present invention will be described in detail.
In the present invention, the "re-peelable type" refers to a type capable of repeatedly attaching and detaching to an adherend.

[Outline of the invention]
By the way, in the conventional re-peelable adhesive film (adhesive body), there is a problem that the adhesive deteriorates with time and adhesive residue is generated when the adhesive film is peeled off from the adherend. In particular, the re-peelable adhesive material applied to a packaging material for storing a wet sheet impregnated with a liquid has a remarkable occurrence of such a problem. The present inventor has conducted diligent research for the purpose of solving such a problem. As a result, they have found that ultraviolet rays have a great influence on the deterioration of the pressure-sensitive adhesive, and have reached the present invention.

That is, the adhesive body of the present invention is applied to a packaging material for storing a wet sheet impregnated with a liquid, and is re-peeled including a base material, an adhesive and an ultraviolet absorber having a function of absorbing ultraviolet rays. It is provided with a mold adhesive layer.

As described above, when the adhesive layer contains an ultraviolet absorber, deterioration of the adhesive due to ultraviolet rays (particularly, light in the ultraviolet region contained in external light such as sunlight) can be effectively prevented, and the adhesive can be adhered. It is possible to effectively prevent the problem of adhesive residue when the body (for example, an adhesive film or the like) is peeled off from the adherend. In particular, in the re-peelable adhesive body, when the adhesive body is peeled off from the adherend, the adhesive layer is directly exposed to external light, so that the deterioration of the adhesive is likely to proceed due to ultraviolet rays. On the other hand, in the present invention, even in such a re-peelable adhesive body, deterioration of the adhesive due to ultraviolet rays can be sufficiently prevented, and the adhesive body (for example, an adhesive film or the like) is peeled off from the adherend. It is possible to effectively prevent the problem of adhesive residue when doing so.

In particular, the adhesive material of the present invention is applied to a packaging material for storing a wet sheet impregnated with a liquid. In such a packaging material, a plurality of wet sheets are usually stored, and each time the wet sheet, which is a stored item, is taken out, the adhesive layer is irradiated with ultraviolet rays. Further, such a packaging material may be used outdoors where the intensity of ultraviolet rays is strong. Therefore, among various adhesive bodies, the above-mentioned problems are particularly likely to occur, but according to the present invention, the above-mentioned problems can be effectively prevented from occurring.

[Removable adhesive composition]
First, a removable pressure-sensitive adhesive composition that can be suitably used for producing the pressure-sensitive adhesive of the present invention will be described.

The removable pressure-sensitive adhesive composition of the present embodiment used for producing the pressure-sensitive adhesive of the present invention contains a pressure-sensitive adhesive and an ultraviolet-absorbing agent having a function of absorbing ultraviolet rays.

<Adhesive>
Examples of the pressure-sensitive adhesive contained in the removable pressure-sensitive adhesive composition include acrylic type, synthetic rubber type, natural rubber type and the like, but acrylic type pressure-sensitive adhesive is preferable.
This makes it possible to improve the adhesiveness to the adherend.

Acrylic adhesives include acrylic acid, methacrylic acid (hereinafter collectively referred to as "(meth) acrylic acid") or ester compounds thereof (acrylate, methacrylate (hereinafter, these are collectively referred to as "meth (acrylate) acrylate"). ) ”, Etc., as long as it contains a (meth) acrylic acid derivative as a monomer component, and may be a copolymer. Further, it may contain a monomer component other than the above.

The pressure-sensitive adhesive preferably contains a monomer having a saturated aliphatic hydrocarbon group having 5 or more carbon atoms as a constituent component.

As a result, the resistance of the pressure-sensitive adhesive itself to ultraviolet rays can be made excellent, and the above-mentioned deterioration of the pressure-sensitive adhesive and the occurrence of problems of adhesive residue can be more effectively prevented.

In addition, the lipophilicity of the entire removable pressure-sensitive adhesive composition (whole pressure-sensitive adhesive layer) can be made more excellent. As a result, when the removable pressure-sensitive adhesive composition contains an oil absorber described in detail later, the absorbed oil is more preferably retained inside in combination with the effect of containing the oil absorber (effect described in detail later). It is possible to improve the effect of retaining the adhesive force when it comes into contact with oil. Further, the adhesive has a better affinity with the oil absorbent (in particular, the oil absorbent which is a polymer compound having a plurality of alicyclic structures (particularly, an alicyclic structure having no unsaturated bond)). It is possible to more effectively prevent unintentional variation in the composition in the removable pressure-sensitive adhesive composition and the pressure-sensitive adhesive layer, and a more stable oil absorption function is exhibited at each site. To.

As described above, the pressure-sensitive adhesive preferably contains a monomer having a saturated aliphatic hydrocarbon group having 5 or more carbon atoms as a constituent component, but the saturated aliphatic hydrocarbon group has 6 or more carbon atoms. Is more preferable, and 8 or more and 16 or less are more preferable.
As a result, the above-mentioned effects are more prominently exhibited.

Further, the aliphatic hydrocarbon group may have a cyclic structure or a branched chain structure, but a linear structure is preferable.
As a result, the above-mentioned effects are more prominently exhibited.

The proportion of the monomer having an aliphatic hydrocarbon group in the molecule (polymer) constituting the pressure-sensitive adhesive is preferably 50% by mass or more, more preferably 60% by mass or more.
As a result, the above-mentioned effects are more prominently exhibited.

Examples of the monomer constituting the acrylic pressure-sensitive adhesive include a monomer that imparts adhesiveness, a monomer that imparts cohesive force, and a monomer having a crosslinkable functional group.

Examples of the monomer that imparts adhesiveness include ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, and tetradecyl (meth) acrylate. ..

Examples of the monomer that imparts cohesive force include methyl (meth) acrylate, styrene, vinyl acetate, and the like.

Examples of the monomer having a crosslinkable functional group include a monomer having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate, and (meth) acrylic acid. Examples thereof include a monomer having a carboxyl group.

As a result, the resistance of the pressure-sensitive adhesive itself to ultraviolet rays can be made more excellent, and the above-mentioned deterioration of the pressure-sensitive adhesive and the occurrence of problems of adhesive residue can be more effectively prevented.

In addition, the lipophilicity of the entire removable pressure-sensitive adhesive composition (whole pressure-sensitive adhesive layer) can be made more excellent. As a result, when the removable pressure-sensitive adhesive composition contains an oil absorbent which will be described in detail later, the absorbed oil can be more preferably retained inside the oil, coupled with the effect of containing the oil absorbent. The effect of retaining the adhesive force in the case of contact can be made more excellent. Further, the adhesive has a better affinity with the oil absorbent (in particular, the oil absorbent which is a polymer compound having a plurality of alicyclic structures (particularly, an alicyclic structure having no unsaturated bond)). It is possible to more effectively prevent unintentional variation in the composition in the removable pressure-sensitive adhesive composition and the pressure-sensitive adhesive layer, and a more stable oil absorption function is exhibited at each site. To.

The content of the monomer having a polar group (for example, a hydroxyl group, a carboxyl group, an amino group, a salt thereof, etc.) in the molecule (polymer) of the acrylic pressure-sensitive adhesive is preferably sufficiently low.

More specifically, the content of the monomer having a polar group in the molecule (polymer) of the acrylic pressure-sensitive adhesive is preferably 10% by mass or less, and more preferably 5% by mass or less.

This makes it possible to improve the lipophilicity of the entire removable pressure-sensitive adhesive composition (whole pressure-sensitive adhesive layer). As a result, when the removable pressure-sensitive adhesive composition contains an oil absorbent which will be described in detail later, the absorbed oil can be more preferably retained inside, coupled with the effect of containing the oil absorbent, and the oil can be used. The effect of retaining the adhesive force in the case of contact can be made more excellent.
As the pressure-sensitive adhesive, either a solvent type or an emulsion type may be used.

Further, the removable pressure-sensitive adhesive composition preferably contains a cross-linked pressure-sensitive adhesive crosslinked with a cross-linking agent as the pressure-sensitive adhesive.

As a result, the cohesive force of the pressure-sensitive adhesive layer can be made more excellent, and the adhesive residue when peeling from the adherend can be more effectively prevented.

Examples of the cross-linking agent include polyimine compounds such as aliphatic isocyanate compounds, aromatic isocyanate compounds, epoxy compounds, metal chelate compounds and aziridine compounds, melamine resins, urea resins, dialdehydes, methylol polymers, metal alkoxides and metal salts. Etc. can be used. More specifically, for example, hexamethylene diisocyanate (HMDI) or a derivative thereof, an aliphatic isocyanate compound, N, N, N', N'-tetraglycidyl-m-xylene diamine, N, N, N', Epoxy compounds such as N'-tetraglycidyl-4,4-diaminodiphenylmethane, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, 1,3-bis (N, N-diglycidylaminomethyl) toluene , Aluminum chelate compounds such as aluminum-isopropylate, aluminum-sec butyrate, aluminum acetylacetonate, and metal chelate compounds such as titanium chelate compounds such as tetraisopropyl titanate and tetrakis (2-ethylhexoxy) titanate.

The amount of the cross-linking agent is not particularly limited, but is preferably 0.01 parts by mass or more and 2.0 parts by mass or less, and 0.03 parts by mass or more and 1.0 part by mass with respect to 100 parts by mass of the polymer component of the pressure-sensitive adhesive main agent. The amount is more preferably 0.05 parts by mass or more, and further preferably 0.5 parts by mass or less.

As a result, a more appropriate adhesive force that can be more preferably re-peeled can be obtained, and the problem of adhesive residue can be more effectively prevented.

<UV absorber>
The ultraviolet absorber has a function of absorbing ultraviolet rays.

By including such an ultraviolet absorber, deterioration of the adhesive due to ultraviolet rays (particularly, light in the ultraviolet region contained in external light such as sunlight) can be effectively prevented, and a sticky substance (for example, adhesive) can be effectively prevented. It is possible to effectively prevent the problem of adhesive residue when peeling the film or the like from the adherend.

As the ultraviolet absorber, for example, a compound having a conjugated unsaturated bond, particularly an aromatic compound, can be preferably used.
As a result, the absorption efficiency of ultraviolet rays can be made more excellent.

Examples of the compound having a conjugated unsaturated bond include a benzophenone-based UV absorber, a benzotriazole-based UV absorber, a triazine-based UV absorber, a salicylic acid-based UV absorber, a oxalic acid anilide-based UV absorber, and a cyanoacrylate-based UV absorber. Absorbents and the like can be mentioned.

Examples of the benzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, and 2,2'. -Dihydroxy-4-dimethoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, [2-hydroxy-4- (octyloxy) phenyl] ( Phenyl) methanone, bis (2-methoxy-4-hydroxy-5-benzoylphenyl) methane and the like can be mentioned.

Examples of the benzotriazole-based ultraviolet absorber include 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-tert-butylphenyl) benzotriazole, 2-( 2'-Hydroxy-3', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2 -(2'-Hydroxy-3', 5'-di-tert-butylphenyl) 5-chlorobenzotriazole, 2- (2'-hydroxy-3', 5'-di-tert-amylphenyl) benzotriazole, 2- (2'-Hydroxy-4'-octoxyphenyl) benzotriazole, 2- [2'-hydroxy-3'-(3'', 4'', 5'', 6'', -tetrahydrophthalimidemethyl ) -5'-Methylphenyl] benzotriazole, 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazole-2-yl) phenol], 2 -(2H-benzotriazole-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2,2'-methylenebis [6- (2H-benzotriazole-2-yl) -4 -(1,1,3,3-Tetramethylbutyl) phenol], 2- (2H-benzotriazole-2-yl) -p-cresol, 2- (5-chloro-2H-benzotriazole-2-yl) Examples thereof include -6-tert-butyl-4-methylphenol, [2 (2'-hydroxy-5'-metaacryloxyphenyl) -2H-benzotriazole and the like.

Examples of the triazine-based ultraviolet absorber include 2,4-bis (2-hydroxy-4-butoxyphenyl) -6- (2,4-dibutoxyphenyl) -1,3,5-triazine, 2,4. 6-Tris (2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine, 2,4,6-tris [2-hydroxy-4- (3-butoxy-2-hydroxypropyloxy) phenyl] -1,3,5-triazine, 2,4,6-tris (2-hydroxy-4-hexyloxy-3-methylphenyl) -1,3,5-triazine and the like can be mentioned.

Examples of the salicylic acid-based ultraviolet absorber include phenylsalicylate, p-tert-butylphenylsalicylate, p-octylphenylsalicylate and the like.

Examples of the cyanoacrylate-based ultraviolet absorber include 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate, ethyl-2-cyano-3,3'-diphenylacrylate and the like.

Further, as the ultraviolet absorber, for example, an inorganic material such as titania can be used. Inorganic materials (particularly, titania) are particularly excellent in chemical stability and the like, and can exhibit a function of absorbing ultraviolet rays more stably for a longer period of time.

The content of the ultraviolet absorber contained in the removable pressure-sensitive adhesive composition is not particularly limited, but is preferably 0.1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the pressure-sensitive adhesive. It is more preferably 3 parts by mass or more and 5 parts by mass or less.

If the content of the ultraviolet absorber is too low, the effect of containing the ultraviolet absorber as described above may not be sufficiently exhibited depending on the type of the ultraviolet absorber and the like. Further, if the content of the ultraviolet absorber is too high, the content of the pressure-sensitive adhesive is relatively low, and the function of the pressure-sensitive adhesive may not be fully exhibited.

<Oil absorber>
The removable pressure-sensitive adhesive composition may contain an oil absorbent having a function of absorbing oil.

As a result, when the adhesive body comes into contact with the oil, the oil can be efficiently absorbed and retained, and the amount of the oil present on the contact surface with the adherend can be reduced. As a result, the adhesive force to the adherend can be suitably maintained even when it comes into contact with the oil.

Examples of the oil include hydrocarbons having 5 or more carbon atoms, fatty acids having 5 or more carbon atoms and ester compounds thereof (including fats and oils such as esters with polyhydric alcohols such as glycerin (for example, triglyceride)). Examples thereof include various silicone oils (for example, methicone, cyclomethicone, etc.).

In addition to mineral oil and synthetic oil, the oil also includes olive oil, sesame oil, jojoba oil, vegetable oil, fish oil, animal oil such as lard, and the like.

The oil absorber can be any material as long as it has a function of absorbing the oil and taking the oil in contact with the pressure-sensitive adhesive layer into the inside of the pressure-sensitive adhesive layer, or a function of retaining the oil in the pressure-sensitive adhesive layer. However, examples thereof include a porous body having pores inside (including agglomerates of fillers and the like), a gelling agent that swells and gels by absorbing oil, and the like.

Such an oil absorbent can take in oil inside the oil absorbent with higher efficiency and more preferably maintain the state. Therefore, by using such an oil absorbent, the above-mentioned effects are more prominently exhibited.

The porosity of the porous body is not particularly limited, but is preferably 10% by volume or more and 80% by volume or less, and more preferably 15% by volume or more and 70% by volume or less.

As a result, more oil can be absorbed, the mechanical strength of the porous body can be improved, and the absorbed oil can be held more stably.

The porous body is preferably in the form of particles.
When the porous body is in the form of particles as an aggregate, the average particle size (secondary particle size) of the porous body is preferably 0.1 μm or more and 30 μm or less, and 1.0 μm or more and 15 μm or less. Is more preferable.

As a result, while improving the dispersion stability and coatability of the porous body in the removable pressure-sensitive adhesive composition, it is more effective to generate undesired irregularities on the surface of the formed pressure-sensitive adhesive layer. Can be prevented.

In the present specification, the average particle size refers to a volume-based average particle size unless otherwise specified. For example, the dispersion liquid of the target particles is manufactured by a Coulter counter method particle size distribution measuring instrument (COOLTER ELECTRONICS INC). It can be obtained by measuring with a TA-II type, etc.) using an aperture of 50 μm.

Examples of the constituent materials of the porous body include calcium silicate, calcium carbonate, diatomaceous earth, silicon dioxide (silica), aluminum oxide (alumina), montmorillonite, clay minerals such as kaolin, various glasses, various metals, salt and the like. Examples thereof include inorganic compounds such as calcium lactic acid, low molecular weight organic compounds such as lactose, starches such as dextrin, processed starch and porous starch, cellulose derivatives such as crystalline cellulose, methyl cellulose and cellulose ether compound, and polyvinyl alcohol.

Further, the porous body may be one that has been subjected to a surface treatment such as a hydrophobic treatment (oil-forming treatment).

This improves the affinity between the porous body and the oil, and the porous body can absorb the oil with higher efficiency.

In particular, in the case of a porous body, it is preferable that the inner wall surface of the pores is hydrophobized.
As a result, the above-mentioned effect is more prominently exhibited.

Examples of the hydrophobization treatment include a method of treating with a coupling agent such as a silane-based coupling agent and a titanate-based coupling agent, and a metal soap treatment method using a zinc salt, a magnesium salt, or an aluminum salt of a fatty acid. Can be mentioned.

Further, as the oil absorbent, a polymer compound having a plurality of alicyclic structures may be used in the repeating unit.

As a result, the affinity between the oil absorbent and the oil is improved, and the oil absorbent can absorb the oil with higher efficiency. Further, such an oil absorber (particularly, a polymer compound having an alicyclic structure having no unsaturated bond) is a pressure-sensitive adhesive as described above (particularly, a saturated aliphatic hydrocarbon group having 5 or more carbon atoms). It has a particularly excellent affinity with a pressure-sensitive polymer as a polymer containing a monomers having It can be effectively prevented, and a more stable oil absorption function is exhibited at each site.

In particular, the oil absorbent material preferably has a chemical structure represented by the following formula (1).

（ただし、式（１）中、ｎは２以上の整数、ｍは１以上４以下の整数を示す。）

(However, in equation (1), n is an integer of 2 or more, and m is an integer of 1 or more and 4 or less.)

As a result, the above-mentioned effects are more prominently exhibited.

The removable pressure-sensitive adhesive composition may contain a plurality of types of oil absorbents. As a result, these act synergistically, and the above-mentioned effects are more prominently exhibited. In particular, when it contains a plurality of types of oil absorbents having different action mechanisms (for example, when a porous body and a polymer compound having a plurality of alicyclic structures are contained in a repeating unit, etc.), as described above. The effect is even more pronounced. More specifically, for example, as an oil absorbent, a component that mainly contributes to rapid oil absorption (for example, a polymer compound having a plurality of alicyclic structures in a repeating unit) and a pressure-sensitive adhesive layer. When containing components that have the function of storing absorbed oil (eg, porous bodies, etc.), the movement of oil between these components results in rapid oil absorption and long-term oil exudation. Both prevention and prevention can be achieved, and excellent effects can be stably obtained.

The content of the oil absorbent contained in the removable pressure-sensitive adhesive composition is not particularly limited, but is preferably 0.1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the pressure-sensitive adhesive. It is more preferably 5 parts by mass or more and 30 parts by mass or less, and further preferably 5 parts by mass or more and 20 parts by mass or less.

If the content of the oil absorbent is too low, the effect of including the oil absorbent as described above may not be sufficiently exhibited depending on the type of the oil absorbent. Further, if the content of the oil absorbent is too high, the content of the pressure-sensitive adhesive may be relatively low, and the function of the pressure-sensitive adhesive may not be fully exhibited.

<Plasticizer>
The removable pressure-sensitive adhesive composition may contain a plasticizer.
This makes it possible to improve the flexibility and elasticity of the removable pressure-sensitive adhesive composition. Further, the removability of the pressure-sensitive adhesive layer formed by using the re-peelable pressure-sensitive adhesive composition can be further improved, and a pressure-sensitive adhesive produced by using the re-peelable pressure-sensitive adhesive composition (for example). , Adhesive film) can be made more excellent in the feeling of turning over when peeling from the adherend.

Examples of the plasticizer include phthalic acid ester-based plasticizers such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, di-n-octyl phthalate, and dicyclohexyl phthalate, trioctyl trimellitic acid, and trimerit. Trimellitic acid ester-based plasticizers such as triisononyl acid, triisodecyl trimellitic acid, 2-ethylhexyl trimellitic acid, polyester-based plasticizers such as phthalic acid-based polyester, tricresyl phosphate, trioctyl phosphate, triphenyl phosphate and the like. Examples thereof include an acid ester-based plasticizer, an epoxidized linseed oil, and an epoxidized plasticizer such as butyl epoxidized stearate, and those having an alkylene group having 4 or more carbon atoms in the molecule are preferable.

Thereby, the resistance of the plasticizer to ultraviolet rays can be further improved, the resistance to ultraviolet rays of the removable pressure-sensitive adhesive composition as a whole, and the pressure-sensitive adhesive layer formed by using the removable pressure-sensitive adhesive composition. Can be made more resistant to UV light.

In addition, the lipophilicity of the entire removable pressure-sensitive adhesive composition (whole pressure-sensitive adhesive layer) becomes more excellent. As a result, when the above-mentioned plasticizer is contained together with the oil absorbing material, the absorbed oil can be more preferably retained inside in combination with the effect of containing the oil absorbing material, and when it comes into contact with the oil, it is possible to hold the absorbed oil inside. The effect of retaining the adhesive strength can be made more excellent. Further, the affinity between the plasticizer and the oil absorbent (among others, the oil absorbent which is a polymer compound having a plurality of alicyclic structures (particularly, an alicyclic structure having no unsaturated bond)) and the plasticizer The affinity with a pressure-sensitive adhesive (particularly, a pressure-sensitive adhesive having a suitable chemical structure as described above) can be further improved, and the releasable pressure-sensitive adhesive composition is unwilling to be used in the pressure-sensitive adhesive layer. It is possible to more effectively prevent variations in the composition, and a more stable oil absorption function is exhibited at each site.

Further, as the plasticizer, it is preferable to use a plasticizer having no aromatic ring structure in the molecule.

Thereby, the resistance of the plasticizer to ultraviolet rays can be further improved, the resistance to ultraviolet rays of the removable pressure-sensitive adhesive composition as a whole, and the pressure-sensitive adhesive layer formed by using the removable pressure-sensitive adhesive composition. Can be made more resistant to UV light.

In addition, the lipophilicity of the entire removable pressure-sensitive adhesive composition (whole pressure-sensitive adhesive layer) becomes more excellent. As a result, when the above-mentioned plasticizer is contained together with the oil absorbing material, the absorbed oil can be more preferably retained inside in combination with the effect of containing the oil absorbing material, and when it comes into contact with the oil, it is possible to hold the absorbed oil inside. The effect of retaining the adhesive strength can be made more excellent. Further, the affinity between the plasticizer and the oil absorbent (among others, the oil absorbent which is a polymer compound having a plurality of alicyclic structures (particularly, an alicyclic structure having no unsaturated bond)) and the plasticizer The affinity with a pressure-sensitive adhesive (particularly, a pressure-sensitive adhesive having a suitable chemical structure as described above) can be further improved, and the releasable pressure-sensitive adhesive composition is unwilling to be used in the pressure-sensitive adhesive layer. It is possible to more effectively prevent variations in the composition, and a more stable oil absorption function is exhibited at each site.

When the plasticizer is an ester compound of a polyvalent carboxylic acid component and an alcohol component, the alcohol component preferably has an alkyl group having 8 or more carbon atoms.

As a result, the lipophilicity of the entire removable pressure-sensitive adhesive composition (whole pressure-sensitive adhesive layer) becomes more excellent. As a result, when the plasticizer is contained together with the oil absorbing material, the absorbed oil can be more preferably retained inside in combination with the effect of containing the oil absorbing material, and the adhesive force when in contact with the oil can be maintained. The holding effect can be made better. Further, the affinity between the plasticizer and the oil absorbent (among others, the oil absorbent which is a polymer compound having a plurality of alicyclic structures (particularly, an alicyclic structure having no unsaturated bond)) and the plasticizer The affinity with a pressure-sensitive adhesive (particularly, a pressure-sensitive adhesive having a suitable chemical structure as described above) can be further improved, and the releasable pressure-sensitive adhesive composition is unwilling to be used in the pressure-sensitive adhesive layer. It is possible to more effectively prevent variations in the composition, and a more stable oil absorption function is exhibited at each site.

Examples of the plasticizer satisfying the above conditions include those having a chemical structure represented by the following formula (2) and the following formula (3).

（ただし、式（２）中、ｍは４以上の整数、ｌは８以上の整数を示す。）

(However, in equation (2), m is an integer of 4 or more, and l is an integer of 8 or more.)

（ただし、式（３）中、ｌは８以上の整数を示す。）

(However, in equation (3), l indicates an integer of 8 or more.)

By using such a plasticizer, the lipophilicity of the entire removable pressure-sensitive adhesive composition (whole pressure-sensitive adhesive layer) becomes further excellent. As a result, when the plasticizer is contained together with the oil absorbing material, the absorbed oil can be more preferably retained inside in combination with the effect of containing the oil absorbing material, and the adhesive force when in contact with the oil can be maintained. The holding effect can be further improved. Further, the affinity between the plasticizer and the oil absorbent (among others, the oil absorbent which is a polymer compound having a plurality of alicyclic structures (particularly, an alicyclic structure having no unsaturated bond)) and the plasticizer The affinity with a pressure-sensitive adhesive (particularly, a pressure-sensitive adhesive having a suitable chemical structure as described above) can be further improved, and the releasable pressure-sensitive adhesive composition is unwilling to be used in the pressure-sensitive adhesive layer. It is possible to more effectively prevent variations in the composition, and a more stable oil absorption function is exhibited at each site.

Such an effect is obtained by using at least one of the plastic agent having the chemical structure represented by the above formula (2) and the plastic agent having the chemical structure represented by the above formula (3) in the above-mentioned plurality of alicyclic structures (particularly). , An oil absorbent which is a polymer compound having an unsaturated bond) and a pressure-sensitive adhesive containing a monomer having an aliphatic hydrocarbon group having 5 or more carbon atoms as a constituent component. Is more prominent.

The content of the plasticizer contained in the removable pressure-sensitive adhesive composition is not particularly limited, but is preferably 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the pressure-sensitive adhesive, and is preferably 5 parts by mass or more and 25 parts by mass. It is more preferably less than parts by mass.

If the content of the plasticizer is too low, the effect of containing the above-mentioned plasticizer may not be sufficiently exhibited depending on the type of the plasticizer and the like. Further, if the content of the plasticizer is too high, the content of the pressure-sensitive adhesive may be relatively low, and the function of the pressure-sensitive adhesive may not be fully exhibited.

<Other ingredients>
The removable pressure-sensitive adhesive composition may contain components (other components) other than those described above. Examples of such components include various resins, curing catalysts, solvents, softeners, dyes, colorants such as pigments, antioxidants such as anilides and phenols, dispersants, leveling agents, and antistatic agents. Can be mentioned.

Examples of the light stabilizer include a hindered amine-based light stabilizer, an ultraviolet stabilizer, and the like.

Examples of the hindered amine-based light stabilizer include [bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate] and bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate. , Methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate and the like.

Examples of the ultraviolet stabilizer include nickel bis (octylphenyl) sulfide, [2,2'-thiobis (4-tert-octylphenolate)] -n-butylamine nickel, and nickel complex -3,5-di-tert-. Examples thereof include butyl-4-hydroxybenzyl-phosphate monoethylate, nickel-dibutyldithiocarbamate, and benzoate type quenchers.

The content of these components is not particularly limited, but it is preferable that the content of these components (other components) excluding the solvent does not exceed 10% by mass.

[Adhesive body]
Next, the adhesive body of the present invention will be described in detail.
<First Embodiment>
FIG. 1 is a schematic vertical sectional view showing a first embodiment of the adhesive body (adhesive film) of the present invention.

As shown in FIG. 1, the adhesive film (removable adhesive film) 10 as an adhesive body includes a base material 1 and a removable adhesive layer 2. The pressure-sensitive adhesive layer 2 is made of a material containing a pressure-sensitive adhesive and an ultraviolet absorber having a function of absorbing ultraviolet rays.

This makes it possible to provide a re-peelable adhesive film 10 that is less likely to generate adhesive residue when peeled from the adherend due to deterioration over time.

In addition, in this specification, "adhesive film" shall include the concept of an adhesive sheet, an adhesive tape and an adhesive label.

The base material 1 has a function of supporting the pressure-sensitive adhesive layer 2.
The base material 1 may be in any form, for example, a dense body, a woven fabric, a non-woven fabric, a paper, a porous body, a synthetic paper such as polypropylene or polyester, a foam, or the like.

The constituent material of the base material 1 is not particularly limited, and examples thereof include a resin material, a metal material, a vegetable fiber such as pulp, and an animal fiber such as wool, and a resin material is preferably used.

Examples of the resin material constituting the base material 1 include polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate and polyethylene naphthalate; acetate resins and acrylonitrile-butadiene-styrene copolymer (ABS). Examples thereof include resin, polystyrene, polyvinyl chloride and the like, and one or a combination of two or more selected from these can be used. Further, as the base material 1, for example, one having a metal film formed by a vapor phase film forming method or the like, for example, an aluminum vapor deposition film may be used.

Further, the base material 1 may contain components other than those described above. Examples of such components include colorants such as dyes and pigments, antioxidants such as anilide and phenol, ultraviolet absorbers such as benzophenone and benzotriazole, light stabilizers, modifiers and rust preventives. Agents, fillers, surface lubricants, corrosion inhibitors, heat stabilizers, lubricants, antistatic agents, polymerization inhibitors, cross-linking agents, catalysts, plasticizers, leveling agents, thickeners, softeners, dispersants, etc. Be done.

Further, the base material 1 may be composed of a single layer or may be a laminated body having a plurality of layers. Further, the base material 1 may be made of, for example, a functionally graded material whose composition changes in a gradient in the thickness direction.

In addition, a primer layer can be formed on the base material 1 or a corona treatment or the like can be applied to the base material 1 in order to improve the adhesion to the pressure-sensitive adhesive layer 2. Examples of the primer layer include acrylic, olefin, polyester and polyurethane.

As a result, the adhesive force between the base material 1 and the adhesive layer 2 can be made particularly large with respect to the adhesive force between the adhesive layer 2 and the adherend, and the adhesive film 10 can be attached to the adherend. It is possible to more effectively prevent the pressure-sensitive adhesive layer 2 from peeling off from the base material 1 and remaining on the adherend at the time of peeling.

The thickness of the base material 1 is not particularly limited, but is preferably 15 μm or more and 300 μm or less, and more preferably 20 μm or more and 50 μm or less.

The pressure-sensitive adhesive layer 2 may be made of a material containing a pressure-sensitive adhesive and an ultraviolet-absorbing agent having a function of absorbing ultraviolet rays, but it is preferable to use the above-mentioned removable pressure-sensitive adhesive composition. Can be formed.

The content of the ultraviolet absorber contained in the pressure-sensitive adhesive layer 2 is not particularly limited, but is preferably 0.1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the pressure-sensitive adhesive, and is preferably 0.3 parts by mass. It is more preferably 3 parts by mass or less.

If the content of the ultraviolet absorber is too low, the effect of containing the ultraviolet absorber as described above may not be sufficiently exhibited depending on the type of the ultraviolet absorber and the like. Further, if the content of the ultraviolet absorber is too high, the ultraviolet absorber may remain on the adherend.

The content of the oil absorbent contained in the pressure-sensitive adhesive layer 2 is not particularly limited, but is preferably 0.1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the pressure-sensitive adhesive, and is preferably 1 part by mass or more and 30 parts by mass. It is more preferably 5 parts by mass or less and 20 parts by mass or less.

If the content of the oil absorbent is too low, the effect of including the oil absorbent as described above may not be sufficiently exhibited depending on the type of the oil absorbent. Further, if the content of the oil absorbent is too high, the content of the pressure-sensitive adhesive may be relatively low, and the function of the pressure-sensitive adhesive may not be fully exhibited.

The thickness of the pressure-sensitive adhesive layer 2 is not particularly limited, but is preferably 1 μm or more and 100 μm or less, more preferably 3 μm or more and 50 μm or less, and further preferably 5 μm or more and 30 μm or less.

[Manufacturing method of adhesive film]
Next, the method for producing the pressure-sensitive adhesive film of the present invention will be described.

<First Embodiment>
FIG. 2 is a schematic vertical sectional view showing a first embodiment of the method for producing an adhesive body (adhesive film) of the present invention.

The manufacturing method of the present embodiment includes a base material preparing step (1a) for preparing the base material 1 and a pressure-sensitive adhesive layer forming step (1b) for forming the pressure-sensitive adhesive layer 2 on the surface of the base material 1. ..

First, the base material 1 as described above is prepared (1a). Prior to the pressure-sensitive adhesive layer forming step described later, a primer layer as described above may be formed on the prepared base material 1, or a corona treatment may be performed.

Next, the pressure-sensitive adhesive layer 2 is formed on the base material 1 (1b).
The method for forming the pressure-sensitive adhesive layer 2 is not particularly limited, but it can be suitably formed by applying the above-mentioned removable pressure-sensitive adhesive composition on one surface of the prepared base material 1.

To apply the removable pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer 2, for example, a liquid re-peelable pressure-sensitive adhesive composition (coating liquid) is applied to a roll coat, a reverse coat, a knife coat, a die coat, and a gravure. It can be performed by coating on the base material 1 by various coating methods such as coating and bar coating.

Further, when forming the pressure-sensitive adhesive layer 2, the removable pressure-sensitive adhesive composition may be mixed with other components to prepare a coating liquid. For example, when forming the pressure-sensitive adhesive layer 2, the removable pressure-sensitive adhesive composition may be mixed with water or a solvent.

Examples of the solvent include ester solvents such as ethyl acetate and butyl acetate, ketone solvents such as methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone, aromatic hydrocarbon solvents such as toluene and xylene, and the like, which are selected from these. One type or a combination of two or more types can be used.

The coating liquid may be any one that can be coated, and the solid content concentration in the coating liquid is not particularly limited, but is preferably 20% by mass or more and 70% by mass or less, and 25% by mass or more and 60% by mass or less. Is more preferable.

Further, the pressure-sensitive adhesive layer 2 may be formed once on the release liner and then bonded to the base material 1.

[Packaging material (packaging body)]
Next, a packaging material (packaging body) to which the adhesive body of the present invention is applied will be described.

FIG. 3 is a perspective view showing a preferred embodiment of the package (packaging material), and FIG. 4 is a cross-sectional side view of the package (packaging material) shown in FIG. 3 in a closed state (when not in use). FIG. 5 is a cross-sectional side view of the package (packaging material) shown in FIG. 3 in an open state (when used). In the following description, the upper side in FIGS. 4 and 5 is referred to as "upper", the lower side is referred to as "lower", the left side in FIGS. 3 to 5 is referred to as "base end portion", and the right side is referred to as "tip portion". To tell.

As shown in FIGS. 3 to 5, the package P1 has a packaging material P2 and a stored object P10 housed in a space S formed inside the packaging material P2.

The stored object P10 is a sheet (wet sheet) P11 impregnated with a liquid, and a plurality of sheets (for example, 6 or more and 100 or less) are stored in such a sheet P11 in a desired folded state. Specific examples of the liquid-impregnated sheet P11 include wet tissues, makeup removing sheets, oil removing papers, medicated papers, antibacterial papers, wipes, automobile papers, window cleaning papers, toilet cleaning papers and the like.

The liquid impregnated in the sheet P11 is appropriately determined depending on its intended use, and is, for example, water, oil components (for example, cleansing oil, paraffin, liquid paraffin, wax, petrolatum, ceresin, montan wax, jojoba seed oil, sunflower). Contains oils, etc.), volatile components such as alcohol, surfactants, lotions, moisturizing components such as glycerin, fragrances, antibacterial agents, and the like. Among these, cleansing oils include mineral oils and silicone oils.

The packaging material P2 is composed of a packaging material main body P3 and a lid body P4 as a base material 1. The packaging material main body P3 has a space S for storing a stored object P10, that is, a plurality of sheets P11, and a sheet material P31 (film) having a desired shape is appropriately formed and joined to form a bag. It was done. For example, the openings at both ends of the tubular sheet material P31 are sealed by fusion (heat fusion, high frequency fusion, ultrasonic fusion, etc.) or adhesion to form a sealing portion P32, and the sheet material P31 is formed into a bag shape. It was done.

The sheet material P31 is preferably a laminate of a resin material that does not allow liquid or gas to permeate and a resin material that has fusion property.

Examples of the resin material that does not allow liquid or gas to permeate include polyesters such as polyethylene terephthalate and polybutylene terephthalate.
Examples of the resin material having fusing property include polyolefins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer.

Further, the sheet material P31 may be a single layer or a laminated body having a plurality of layers. When the sheet material P31 is composed of a laminated body, examples thereof include those in which two or more different resin layers are laminated among the resin materials exemplified above. Further, a resin layer to which a metal layer (for example, a metal foil, a metal vapor deposition layer, etc.) is bonded may be used. Examples of the type of metal constituting the metal layer include aluminum or aluminum alloy, stainless steel and the like.

As described above, by forming the sheet material P31 with a laminated body, particularly by having the laminated body having a metal layer, the gas impermeableness (gas barrier property) of the sheet material P31 is improved and the impermeableness of ultraviolet rays is imparted. It is possible to improve the storage stability of the stored item P10.

Further, the sheet material P31 may be subjected to various surface treatments, for example, a surface treatment for enhancing the adhesion to the pressure-sensitive adhesive layer 2. For example, at least the portion of the sheet material P31 to which the pressure-sensitive adhesive layer 2 is attached (the upper surface of the outer peripheral portion P24 and the upper surface of the broken fragment P23) is surface-treated to improve the adhesion and airtightness with the pressure-sensitive adhesive layer 2. It may be an applied one.

Further, on the surface of the sheet material P31, various functional layers such as a printing layer (printing coat layer) for printing characters and figures, a protective layer, and a layer for improving surface texture (gloss, etc.) are provided. It may be provided. Such a functional layer may also be provided on the upper surface of the lid P4.

The thickness of the sheet material P31 is not particularly limited, but is preferably 15 μm or more and 500 μm or less, and more preferably 20 μm or more and 100 μm or less.

When such a packaging material main body P3 is used, an opening P22 for taking out a sheet P11 which is a stored object P10 is formed. FIG. 4 shows a state in which the package P1 is not used, that is, before the lid P4 is closed and the opening P22 is formed. As shown in FIG. 4, an easily broken portion P21 composed of, for example, a half cut, a notch (V-order groove), a perforation, or the like is provided linearly on the upper portion of the packaging material main body P3. The easily broken portion P21 has a smaller breaking strength than other parts of the sheet material P31 (near the easily broken portion P21), and when an external force is applied, the sheet material P31 is broken at the easily broken portion P21 and opened. Will be done. The easily broken portion P21 is formed in a shape corresponding to the contour of the opening P22 (for example, a circular shape, an elliptical shape, an oval shape, a square shape), and after the easily broken portion P21 is broken, the easily broken portion of the sheet material P31 is formed. The portion surrounded by P21 (the portion inside the easily broken portion P21) becomes the fracture fragment P23.

The lid P4 is for closing the opening P22, and is made of a sheet material (film) having the same flexibility as the sheet material P31. As the constituent material of the lid P4, the same material as the constituent material of the base material 1 described above can be mentioned, and the preferable thickness thereof is also the same as the thickness of the base material 1. The sheet material constituting the lid P4 and the sheet material P31 constituting the packaging material P2 may have different constituent materials and thicknesses.

The lid P4 has a base end portion P41 located on the left side in FIG. 4, and has a tab P42 at the end portion (tip portion) on the opposite side thereof. The tab P42 is pinched with fingers and the lid P4 is lifted upward from the tip end side to form (open) the opening P22 or to expose the already formed opening P22. During such an operation, the base end portion P41 of the lid body P4 does not peel off the pressure-sensitive adhesive layer 2 immediately below the lid body P4, and maintains the adhered state. As a result, when the sheet P11 is taken out from the opening P22, the lid P4 is maintained in a connected state with the packaging material main body P3 at its base end portion P41.

An adhesive layer 2 to be described in detail later is formed (bonded) on the lower surface of the lid P4 (the surface on the packaging material main body P3 side) by, for example, coating, and the adhesive layer 2 is formed with the packaging material main body P3. It is joined to the lid P4. The pressure-sensitive adhesive layer 2 is formed on the lower surface of the lid P4 except for the tab P42.

The bonding strength of the pressure-sensitive adhesive layer 2 to the lid P4 is larger than the bonding strength to the packaging material main body P3 (preferably 1.2 times or more and 50 times or less). As a result, when the lid P4 is lifted upward from the tab P42 side to form (open) or expose the opening P22, the adhesive layer 2 is maintained in a state of being joined to the lid P4 side while maintaining the state of being joined to the lid P4 side. Peel off from the packaging material body P3. In particular, the adhesive residue on the packaging material main body P3 side, that is, the residue on the outer peripheral portion P24 surface of the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer 2 is also prevented.

As shown in FIG. 4, when the package P1 is unused, the easily broken portion P21 is not broken, and the adhesive layer 2 formed on the lid P4 is attached to the upper surface of the packaging material main body P3. ing. The pressure-sensitive adhesive layer 2 is formed in a region including an easily broken portion P21, that is, an opening P22 formed later, and the easily broken portion P21 and an inner portion thereof (with a broken fragment P23) are formed by the pressure-sensitive adhesive layer 2 and the lid P4. The outer peripheral portion P24 of the easily broken portion P21 is covered.

From this state, when the tab P42 is pinched with a finger and the lid P4 is lifted upward from the tip end side, the adhesive layer 2 is joined to the lid P4 side as shown in FIGS. 3 and 5. While maintaining it, it is peeled off from the packaging material main body P3. At this time, the inner portion of the easily broken portion P21, that is, the portion to be the broken fragment P23 is maintained in a state of being attached to the lower surface of the pressure-sensitive adhesive layer 2 and lifted together with the lid P4, so that the easily broken portion P21 is removed. It gradually breaks and the opening P22 is formed (opened). The pressure-sensitive adhesive layer 2 is peeled off at the outer peripheral portion P24 near the outer side of the easily broken portion P21. The pressure-sensitive adhesive layer 2 at the base end portion P41 of the lid P4 is left (the pressure-sensitive adhesive layer 2 at the base end portion P41 is maintained in a state of being attached without peeling from the sheet material P31). When 2 is peeled off from the outer peripheral portion P24 of the easily broken portion P21 of the sheet material P31, almost the entire easily broken portion P21 is broken, and the broken fragment P23 is attached to the adhesive layer 2 (shifts to the lid P4 side). Along with this, the opening P22 is formed. In this way, the packaging material P2 is opened.

After the packaging material P2 is opened as described above, the sheet P11 at the uppermost portion of the stored items P10 can be pinched with fingers and taken out from the opening P22. Normally, the sheets P11 are taken out one by one, but a plurality of sheets may be taken out at the same time.

After taking out the sheet P11, the lid P4 is returned to the original state (the state shown in FIG. 4). That is, the pressure-sensitive adhesive layer 2 is reattached to the outer peripheral portion P24 (region surrounding the opening P22) of the opening P22 formed in the sheet material P31 located on the upper side of the packaging material main body P3. As a result, the opening P22 is sealed. At this time, the fragment P23 returns to the inside of the opening P22 to seal the opening P22, and the pressure-sensitive adhesive layer 2 preferably adheres to the outer peripheral portion of the opening P22 of the sheet material P31 without a gap. The airtightness can be ensured. This prevents the liquid impregnated in the stored item P10 from volatilizing and being released to the outside of the packaging material P2 (drying of the stored item P10) during the subsequent storage. Further, during storage, it is possible to prevent dust, dust, bacteria and the like from invading the packaging material P2 from the outside and contaminating the stored material P10.

In this way, when the next sheet P11 is taken out from the state where the opening P22 is sealed by the lid P4 (the state shown in FIG. 4), the tab P42 is pinched with a finger and the lid P4 is moved upward from the tip side. When lifted to, the pressure-sensitive adhesive layer 2 is peeled off from the outer peripheral portion P24 while maintaining the state of being joined to the lid P4 side. Since the easily broken portion P21 is already broken, the broken fragment P23 is also lifted together with the lid P4 while maintaining the state of being attached to the pressure-sensitive adhesive layer 2, and the opening P22 is gradually exposed from the tip end side. When the pressure-sensitive adhesive layer 2 is peeled off from the outer peripheral portion P24 while leaving the pressure-sensitive adhesive layer 2 at the base end portion P41 of the lid P4, almost the entire opening P22 is exposed. In this way, the packaging material P2 is opened again. As a result, the sheet P11 at the top can be taken out again.

After taking out the sheet P11, the adhesive layer 2 is reattached to the outer peripheral portion P24 of the opening P22, and the lid P4 is closed (returning to the original state shown in FIG. 4). As a result, the opening P22 is resealed. In this way, the work of taking out the sheet P11 is performed a plurality of times, and each time the sheet P11 is taken out, the adhesive layer 2 is peeled off and attached from the outer peripheral portion P24. That is, in the package P1, peeling and sticking of the pressure-sensitive adhesive layer 2 from the outer peripheral portion P24 are repeatedly performed (hereinafter referred to as “multiple peeling / sticking operations”). This number of times may correspond to the number of sheets P11 stored in the unused packaging material P2.

The pressure-sensitive adhesive layer 2 is formed on the lower surface (back surface) of the lid P4 with the lid P4 as the base material 1. The lid P4 (base material 1) and the adhesive layer 2 constitute an adhesive film 10 having the packaging material main body P3 as an adherend.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto.

For example, the pressure-sensitive adhesive body (for example, a pressure-sensitive adhesive film) may have at least one coating layer on the surface side opposite to the surface facing the pressure-sensitive adhesive layer of the base material. For example, a printing layer may be provided on the surface side of the base material opposite to the surface facing the pressure-sensitive adhesive layer. Further, a printing coat layer or the like may be provided in order to improve the adhesion to the printing layer. Further, a coat layer having a function of protecting the surface of the adhesive film may be provided.

Further, in the above-described embodiment, the case where the pressure-sensitive adhesive is a pressure-sensitive adhesive film provided with a film-like base material and forming a film-like shape as the entire pressure-sensitive adhesive body has been typically described. The shape is not limited to the film shape and may be any shape.

Further, the laminating material may be coated on the surface side of the base material (adhesive film base material) opposite to the surface facing the pressure-sensitive adhesive layer. As the laminating material, for example, a material having a laminated base material and a pressure-sensitive adhesive layer (laminated pressure-sensitive adhesive layer) can be used.

Further, in the present invention, the ultraviolet absorber may be contained at least in the pressure-sensitive adhesive layer, but may be further contained in other constituents of the pressure-sensitive adhesive. For example, the ultraviolet absorber may be applied to at least one of a base material of an adhesive film as an adhesive body (adhesive film base material), a printing layer, and a laminating material (laminated base material, adhesive layer (laminated adhesive layer)). It may be included.

Further, the packaging material to which the adhesive body of the present invention is applied is not limited to the one having the above-mentioned structure, and may have any structure as long as it accommodates the wet sheet.

The present invention will be described in more detail with reference to specific examples below, but the present invention is not limited to these examples. In the following description, the treatments that do not particularly indicate the temperature conditions were performed at room temperature (23 ° C.) and a relative humidity of 50%. Further, among various measurement conditions, those showing no particular temperature condition are numerical values at room temperature (23 ° C.).

[1] Production of Adhesive Film (Example 1)
An acrylic copolymer (acrylic pressure-sensitive adhesive) having a monomer composition as shown in Table 1 and having a weight average molecular weight of 800,000, and 1,3-bis (N, N-di) as an epoxy-based cross-linking agent. Glycidylaminomethyl) cyclohexane and 2- (2H-benzotriazole-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol as UV absorbers, multiple in the repeating unit. Quinton 1105 (manufactured by Nippon Zeon Co., Ltd.) as an oil absorber, which is a polymer compound having an alicyclic structure, a compound represented by the following formula (4) as a plasticizing agent, and toluene as a solvent are mixed. A pressure-sensitive adhesive composition (removable type pressure-sensitive adhesive composition) as a coating liquid was prepared.

Next, using a knife coater, the above pressure-sensitive adhesive composition was applied onto a glassine release liner (release paper) so that the thickness after drying was 25 μm.

Then, the solvent was removed by heating at 100 ° C. for 2 minutes, and the adhesive layer was formed by crosslinking at room temperature for 7 days.

Next, a film-like substrate made of polyethylene terephthalate having a thickness of 50 μm and having a corona-treated surface is attached to this pressure-sensitive adhesive layer and aged for one week at a temperature of 23 ° C. and a relative humidity of 50%. As a result, an adhesive film in which the adhesive layer was protected by a release liner was obtained. The film thickness was measured with a micro gauge.

(Examples 2 to 8)
A pressure-sensitive adhesive film was produced in the same manner as in Example 1 except that the composition of the pressure-sensitive adhesive, the composition of the pressure-sensitive adhesive composition, and the composition of the pressure-sensitive adhesive film were as shown in Table 1.

(Comparative Example 1)
A pressure-sensitive adhesive film was produced in the same manner as in Example 8 except that the composition of the pressure-sensitive adhesive, the composition of the pressure-sensitive adhesive composition, and the composition of the pressure-sensitive adhesive film were as shown in Table 1.

Table 1 summarizes the monomer composition of the pressure-sensitive adhesive (acrylic copolymer) used in the production of the pressure-sensitive adhesive films of each of the Examples and Comparative Examples, the composition of the pressure-sensitive adhesive composition, and the structure of the pressure-sensitive adhesive film.

In Table 1, 2-ethylhexyl acrylate is M1, decyl acrylate is M2, tetradecyl acrylate is M3, butyl acrylate is M4, acrylic acid is M5, and 2-hydroxyethyl acrylate is M6, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane is C1, 2- (2H-benzotriazole-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol as an ultraviolet absorber is UA1, UA2 as an ultraviolet absorber, 2,2'-methylenebis [6- (2H-benzotriazole-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol as an ultraviolet absorber ] Is UA3, 2- (2H-benzotriazole-2-yl) as an ultraviolet absorber-p-cresol is UA4, 2- (5-chloro-2H-benzotriazole-2-yl) as an ultraviolet absorber- 6-tert-butyl-4-methylphenol is UA5, Quinton 1105 is OA1, silica as a porous body (AGC SITEC, Sunsphere H-33) is OA2, and silica as a porous body (Tosoh Silica). OA3 for NIPSIL NS-T), OA4 for hollow porous spherical fine particles of methyl methacrylate crosspolymer as a porous body (Matsumoto Microsphere MHB-R, manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.), the above formula (4). The compound represented by is indicated by P1 and polyethylene terephthalate is indicated by PET.

[2] Evaluation <Initial adhesive strength>
The adhesive films of each of the Examples and Comparative Examples (adhesive films protected by a release liner) were cut into a size of 25 mm in width × 150 mm in length to obtain test pieces.

The release liner was peeled off from the obtained test piece, and the exposed pressure-sensitive adhesive layer was brought into contact with a polyethylene terephthalate film having a thickness of 100 μm and pressure-bonded once with a 2 kg roll to bring the pressure-sensitive adhesive film (test piece) into close contact.

After being left for 24 hours, the adhesive strength was measured in a 180 ° peel test in which the material was peeled off at a speed of 300 mm / min in the 180 degree direction using a tensile tester, and evaluated according to the following criteria. The one evaluated by A has the optimum adhesive strength as a removable adhesive film, and B, C, D, and E are separated from the preferable adhesive strength range in this order.

A: Adhesive strength is 4N / 25mm or more and less than 7N / 25mm.
B: Adhesive strength is 3N / 25mm or more and less than 4N / 25mm (however, excluding the range of A)).
C: Adhesive strength is 2N / 25mm or more and less than 3N / 25mm (however, excluding the range of A and B).
D: Adhesive strength is 1N / 25mm or more and less than 2N / 25mm (however, excluding the range of A, B, C).
E: Adhesive strength is less than 1N / 25mm or 7N / 25mm or more.

<Initial glue residue>
Regarding the polyethylene terephthalate film (polyethylene terephthalate film after peeling the adhesive film) used for the evaluation of the initial adhesive strength, the portion where the adhesive film was peeled off was observed and evaluated based on the following criteria.

A: The area ratio of the part where the adhesive film of the adherend is attached and where the adhesive residue remains is less than 1%.
B: The area ratio of the portion where the adhesive film of the adherend is attached and where the adhesive residue is present is 1% or more and less than 20%.
C: The area ratio of the portion where the adhesive film of the adherend is attached and where the adhesive residue is present is 20% or more and less than 40%.
D: The area ratio of the portion where the adhesive film of the adherend is attached and where the adhesive residue is present is 40% or more and less than 60%.
E: The area ratio of the part where the adhesive film of the adherend is attached and where the adhesive residue remains is 60% or more.

<Adhesive strength after UV irradiation>
The adhesive films of each of the Examples and Comparative Examples (adhesive films protected by a release liner) were cut into a size of 25 mm in width × 150 mm in length to obtain test pieces.

The release liner was peeled off from the test piece, and the exposed adhesive surface was irradiated with ultraviolet rays for 10 hours using an ultraviolet fade meter U48 (manufactured by Suga Test Instruments Co., Ltd.).

The test piece irradiated with ultraviolet rays was brought into contact with the polyethylene terephthalate film (adhesive body) and pressure-bonded once with a 2 kg roll to bring the adhesive film (test piece) into close contact.

After being left for 24 hours, the adhesive strength was measured in a 180 ° peel test in which the material was peeled off at a speed of 300 mm / min in the 180 degree direction using a tensile tester, and evaluated according to the following criteria.

A: Adhesive strength is 4N / 25mm or more and less than 7N / 25mm.
B: Adhesive strength is 3N / 25mm or more and less than 4N / 25mm.
C: Adhesive strength is 2N / 25mm or more and less than 3N / 25mm.
D: Adhesive strength is 1N / 25mm or more and less than 2N / 25mm.
E: Adhesive strength is less than 1N / 25mm or 7N / 25mm or more.

<Remaining glue after UV irradiation>
Regarding the polyethylene terephthalate film (polyethylene terephthalate film after peeling off the adhesive film) used for the evaluation of the adhesive strength after UV irradiation, the portion where the adhesive film was peeled off was observed and evaluated based on the following criteria.

A: The area ratio of the part where the adhesive film of the adherend is attached and where the adhesive residue remains is less than 1%.
B: The area ratio of the portion where the adhesive film of the adherend is attached and where the adhesive residue is present is 1% or more and less than 20%.
C: The area ratio of the portion where the adhesive film of the adherend is attached and where the adhesive residue is present is 20% or more and less than 40%.
D: The area ratio of the portion where the adhesive film of the adherend is attached and where the adhesive residue is present is 40% or more and less than 60%.
E: The area ratio of the part where the adhesive film of the adherend is attached and where the adhesive residue remains is 60% or more.

<Adhesive force (peeling force) after oil contact>
The adhesive films of each of the Examples and Comparative Examples (adhesive films protected by a release liner) were cut into a size of 25 mm in width × 150 mm in length to obtain test pieces.

A cleansing oil containing mineral oil (mineral oil) and cyclomethicone (silicone oil) was applied to one surface of the polyethylene terephthalate film at 2 g / m ² , and then the release liner was peeled off from the test piece to expose the adhesive. The agent layers were brought into contact with each other and pressure-bonded in the same manner as described above.

After being left for 24 hours, the adhesive strength was measured in a 180 ° peel test in which the material was peeled off at a speed of 300 mm / min in the 180 degree direction using a tensile tester, and evaluated according to the following criteria.

A: Adhesive strength is 4N / 25mm or more and less than 7N / 25mm.
B: Adhesive strength is 3N / 25mm or more and less than 4N / 25mm.
C: Adhesive strength is 2N / 25mm or more and less than 3N / 25mm.
D: Adhesive strength is 1N / 25mm or more and less than 2N / 25mm.
E: Adhesive strength is less than 1N / 25mm or 7N / 25mm or more.
These results are summarized in Table 2.

As is clear from Table 2, excellent results were obtained in the present invention, whereas satisfactory results were not obtained in the comparative examples.

10 ... Adhesive film (removable adhesive film)
1 ... Base material 2 ... Adhesive layer P1 Packaging material P2 Packaging material P21 Easy-breaking part P22 Opening P23 Fragment fragment P24 Outer peripheral part P3 Packaging material body P31 Sheet material P32 Sealing part P4 Cover body P41 Base end part P42 Tab P10 P11 sheet (wet sheet)
S space

Claims (6)

An adhesive that is applied to packaging materials that contain liquid-impregnated wet sheets.
With the base material
It is provided with an adhesive, an ultraviolet absorber having a function of absorbing ultraviolet rays, and a removable adhesive layer containing an oil absorber.
The pressure-sensitive adhesive layer is a porous body and a porous body as the oil absorbent.
A sticky substance containing a polymer compound having a chemical structure represented by the following formula (1) .

(However, in equation (1), n is an integer of 2 or more, and m is an integer of 1 or more and 4 or less.) The adhesive according to claim 1, wherein the ultraviolet absorber contains a compound having a conjugated unsaturated bond. The adhesive according to claim 1 or 2, wherein the content of the ultraviolet absorber with respect to 100 parts by mass of the adhesive is 0.1 parts by mass or more and 10 parts by mass or less. The pressure-sensitive adhesive according to any one of claims 1 to 3 , wherein the content of the oil absorbent with respect to 100 parts by mass of the pressure-sensitive adhesive is 0.1 parts by mass or more and 50 parts by mass or less. The pressure-sensitive adhesive according to any one of claims 1 to 4 , wherein the pressure-sensitive adhesive contains a monomer having a saturated aliphatic hydrocarbon group having 5 or more carbon atoms as a constituent component. The pressure-sensitive adhesive according to any one of claims 1 to 5 , wherein the pressure-sensitive adhesive layer further contains a plasticizer having an alkylene group having 4 or more carbon atoms in the molecule.

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