JP6703429B2 - Adhesive tape - Google Patents

Description

The present invention relates to an adhesive tape.

In a refrigerator or the like, an adhesive tape may be used to fix a refrigerant pipe for circulating a refrigerant.
For example, in Patent Document 1, as a method for fixing a refrigerant pipe to a refrigerator, after the refrigerant pipe is attached to an outer box of a refrigerator or the like using an adhesive tape, foam insulation is provided between the outer box and the adhesive tape. A method of filling the agent is disclosed.

JP, 2013-148281, A

By the way, after fixing the refrigerant pipe to the outer casing of the refrigerator made of metal or the like using adhesive tape, polyurethane foaming agent (heat insulating material) is injected and filled between the outer casing of the refrigerator and the inner casing made of resin. In this case, the surface of the adhesive tape on the side of the adhesive layer is in contact with the side of the housing for adhesively fixing the refrigerant pipe to the outer box of the housing, but the surface of the adhesive tape opposite to the surface on which the back surface treatment is performed ( The back layer) contacts the polyurethane blowing agent. In this case, if the adhesion between the back layer of the adhesive tape and the polyurethane foam in which the polyurethane foam has hardened is poor, the refrigerant pipes etc. may vibrate due to the vibration of the refrigerator compressor or cooling fan motor. Then, peeling between the back surface layer of the adhesive tape and the polyurethane foam progresses, and problems such as noise may occur due to sliding (rubbing) between the refrigerant pipe and the adhesive tape and the polyurethane foam. Further, in this case, the meandering refrigerant pipe which originally has a bend or twist due to elasticity is generated from air or polyurethane foam accumulated in a cavity formed between the adhesive tape and the outer casing of the casing. Due to the pressure difference between the generated gas pressure and the atmospheric pressure due to the temperature change, elastic deformation is likely to occur, and the outer casing of the refrigerator may be corrugated.
On the other hand, when a material having high adhesion to the polyurethane foam is used as the back layer of the adhesive tape, the back layer and the adhesive layer may adhere to each other when the adhesive tape is wound up. In this case, it may be difficult to rewind the adhesive tape, or excessive force may be required when rewinding. Further, as a method for suppressing the adhesion between the back surface layer and the pressure-sensitive adhesive layer, a release liner may be provided on the pressure-sensitive adhesive layer, but workability and resource saving at the time of fixing the refrigerant pipe with the pressure-sensitive adhesive tape It is not preferable from the viewpoint.

The present invention provides a pressure-sensitive adhesive tape that is wound so that a pressure-sensitive adhesive layer overlaps a back surface layer, has good adhesiveness with a polyurethane foam, and can be rewound with good workability. With the goal.

Adhesive tape to which the present invention is applied, a base material made of aluminum, a back layer laminated on one surface of the base material and containing a modified polyolefin resin having a hydroxyl group, and the other surface of the base material. laminated, acrylic urethane pressure-sensitive adhesives, see contains at least consists of one pressure-sensitive adhesive adhesive layer selected urethane-based pressure-sensitive adhesive or, et al., modified polyolefin resin having a hydroxyl group has a hydroxyl value 40 mg KOH / 50 mgKOH / g, and the skeletal polyolefin resin is one selected from polypropylene or polypropylene-α-olefin copolymer, and has a rewinding force of 0.95 N/10 mm to 1.60 N/10 mm. To do .
Here, the back layer may further include a non-silicone release agent.
The base material may be made of soft aluminum foil.
Furthermore, the pressure-sensitive adhesive tape can be characterized in that the pressure-sensitive adhesive layer is wound so that the pressure-sensitive adhesive layer overlaps the back layer without a release liner.

According to the present invention, there is provided a pressure-sensitive adhesive tape that is wound so that a pressure-sensitive adhesive layer overlaps a back surface layer, has good adhesiveness with a polyurethane foam, and has good workability that enables rewinding. can do.

It is the figure which showed an example of the structure of the adhesive tape to which this Embodiment is applied.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[Structure of adhesive tape 1]
FIG. 1 is a diagram showing an example of the configuration of an adhesive tape 1 to which this embodiment is applied. As shown in FIG. 1, the pressure-sensitive adhesive tape 1 according to the present embodiment has a base material 2 made of aluminum foil, a back layer 3 laminated on one surface of the base material 2, and a back surface layer 3 on the other surface of the base material 2. The pressure-sensitive adhesive layer 4 to be laminated is provided.
Although not shown, the pressure-sensitive adhesive tape 1 is an anchor coat layer for improving the adhesion between the base material 2 and the pressure-sensitive adhesive layer 4, if necessary, between the base material 2 and the pressure-sensitive adhesive layer 4. Etc. may be provided.
The adhesive tape 1 of this embodiment does not have a release liner. Therefore, when the adhesive tape 1 is wound into a roll after the adhesive tape 1 is manufactured, the adhesive layer 4 is directly stacked on the back surface layer 3 and the back surface layer 3 and the adhesive layer 4 are brought into contact with each other. To do.

The adhesive tape 1 of the present embodiment is used, for example, in a refrigerator or the like, to fix a refrigerant pipe such as a copper pipe through which a refrigerant circulates to a housing outer case made of metal. An example of a method for fixing the refrigerant pipe to the outer casing of a refrigerator or the like will be described. First, the refrigerant pipe is attached and fixed to the outer casing of the refrigerator with the adhesive tape 1 in the unwound state. After that, the polyurethane foaming agent is injected around the refrigerant pipe adhered to the outer casing of the casing by the adhesive tape 1 (between the outer casing and the inner casing). After that, when the injected polyurethane foaming agent is cured, the periphery of the refrigerant pipe is filled with the cured polyurethane foaming agent (hereinafter, the cured polyurethane foaming agent is referred to as polyurethane foam), and the refrigerator outer casing is packed. The refrigerant pipe is fixed to.
The pressure-sensitive adhesive tape 1 of the present embodiment can be used not only for household refrigerators/freezers but also for commercial refrigerators/freezers and large refrigerating rooms/freezers when fixing the refrigerant pipes. ..

Subsequently, the configuration of each layer of the adhesive tape 1 of the present embodiment will be described.
[Base material 2]
As described above, the base material 2 of the present embodiment is made of aluminum foil.
The thickness of the base material 2 is preferably in the range of 6 μm or more and 150 μm or less, and more preferably in the range of 30 μm or more and 80 μm or less.
When the thickness of the base material 2 is less than 6 μm, the strength of the adhesive tape 1 decreases and the adhesive tape 1 is easily cut. Further, when the thickness of the base material 2 is less than 6 μm, wrinkles and slack are likely to occur in the base material 2 in the manufacturing process of the adhesive tape 1, and the workability of the base material 2 may deteriorate.

On the other hand, when the thickness of the base material 2 is thicker than 150 μm, the thickness of the adhesive tape 1 as a whole becomes large, so that it becomes difficult to cut the adhesive tape 1 during the manufacturing process of the adhesive tape 1 or during use. The handling of the adhesive tape 1 may be difficult. Moreover, when the thickness of the base material 2 is thicker than 150 μm, it becomes difficult for the adhesive tape 1 to follow the refrigerant pipe as the adherend. In this case, the adhesive tape 1 floats from the outer casing of the refrigerator, and the fixing of the refrigerant pipe becomes insufficient, so that the refrigerant pipe or the like vibrates due to vibration of the refrigerator, which may cause noise. Further, it becomes difficult to fix the refrigerant pipe until the polyurethane foaming agent is injected, and it may not be possible to arrange the refrigerant pipe as designed in the refrigerator.

As the aluminum foil forming the base material 2 of the present embodiment, either a soft aluminum foil or a hard aluminum foil may be used, but from the viewpoint of followability to irregularities of the refrigerant pipe or the like that is the adherend, It is preferable to use a soft aluminum foil.
When a hard aluminum foil is used as the base material 2, depending on the thickness of the base material 2, it may be difficult for the adhesive tape 1 to follow the irregularities of the refrigerant pipe or the like that is the adherend.

Here, the hard aluminum foil means an aluminum foil in a state of being worked (rolled) and work-hardened, and examples thereof include an aluminum foil just after work-hardening and an aluminum foil heat-treated after work-hardening. . Specific examples include those of the classification symbols HX1, HX2, HX3, HX4, HX5, HX6, HX7, HX8, and HX9 (provided that X:1 to 3) used in the JIS standard (JIS H 0001).

On the other hand, the soft aluminum foil means an aluminum foil other than the hard aluminum foil described above, and examples thereof include an aluminum foil softened by complete annealing. Specific examples thereof include those referred to as O material in the JIS standard (JIS H 0001).

Further, the aluminum foil used for the base material 2 of the present embodiment may contain impurities such as iron, but the smaller the impurities, in other words, the higher the purity, the better. When the purity of the aluminum foil used as the base material 2 is low, the flexibility of the base material 2 may be reduced, and the adhesive tape 1 may be difficult to follow the irregularities of the refrigerant pipe or the like that is the adherend.

[Back layer 3]
The back surface layer 3 of the present embodiment is configured to contain a modified polyolefin resin having a hydroxyl group. Further, the back surface layer 3 of the present embodiment preferably contains a non-silicone release agent in addition to the modified polyolefin resin having a hydroxyl group.

The polyolefin resin as the skeleton of the modified polyolefin resin having a hydroxyl group contained in the back surface layer 3 is not particularly limited, but for example, polypropylene or polypropylene-α-olefin copolymer is preferably used.

Examples of the α-olefin of the polypropylene-α-olefin copolymer include ethylene, 1-butene, 1-heptene, 1-octene, and 4-methyl-1-pentene. Seeds can be used.
The ratio of polypropylene in the polypropylene-α-olefin copolymer is not particularly limited, but is preferably in the range of 50 mol% to 90 mol% from the viewpoint of solubility in an organic solvent. When the ratio of polypropylene is out of the above range, it may be difficult to dissolve in an organic solvent, and it may be difficult to apply it to the base material 2 made of aluminum foil.

The modified polyolefin-based resin having a hydroxyl group contained in the back surface layer 3 can be obtained, for example, from a modified polyolefin-based resin having an acid group obtained by introducing an acid group into the polyolefin-based resin that serves as the skeleton described above. Specifically, the modified polyolefin-based resin having a hydroxyl group is prepared by introducing a double bond into the modified polyolefin-based resin having an acid group, and then 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxyacrylate. It can be obtained by graft-copolymerizing a hydroxyl group-containing (meth)acrylic acid type monomer such as butyl, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate.

The modified polyolefin resin having an acid group which is a base of the modified polyolefin resin having a hydroxyl group contained in the back surface layer 3 is obtained by adding α,β-unsaturated carboxylic acid or an acid anhydride thereof to the polyolefin resin as the skeleton. It can be obtained by acid modification by graft-copolymerizing at least one of the products.
The α,β-unsaturated carboxylic acid and its acid anhydride are not particularly limited, and examples thereof include maleic acid, itaconic acid, citraconic acid, fumaric acid, aconitic acid, crotonic acid, isocrotonic acid, acrylic acid. And its anhydrides. These may be used alone or in combination of two or more. In the back surface layer 3 of the present embodiment, from the viewpoint of versatility, it is preferable to modify at least one of maleic anhydride and itaconic anhydride by graft-copolymerizing with the polyolefin resin.

In the modified polyolefin resin having an acid group which is a base of the modified polyolefin resin having a hydroxyl group, the graft polymerization amount of the α,β-unsaturated carboxylic acid or its acid anhydride with respect to the polyolefin resin is 0.2% by mass or more. The range is preferably 30 mass% or less, and more preferably 1.0 mass% or more and 10 mass% or less.
When the graft polymerization amount of the α,β-unsaturated carboxylic acid or its acid anhydride is less than 0.2% by mass, the number of hydroxyl groups introduced into the modified polyolefin resin is small, and the solubility in an organic solvent is low. In the manufacturing process of the adhesive tape 1, the stability as a coating liquid for forming the back surface layer 3 may decrease. Further, when the graft polymerization amount of the α,β-unsaturated carboxylic acid or its acid anhydride is less than 0.2% by mass, the adhesion between the back layer 3 and the base material 2, the back layer 3 and the polyurethane foaming agent. There is a risk that the adhesion with will be insufficient.
On the other hand, when the graft polymerization amount of the α,β-unsaturated carboxylic acid or its acid anhydride exceeds 30% by mass, the amount of unreacted substances increases, and it becomes unavoidable that the modified polyolefin resin having a hydroxyl group has a low molecular weight. In this case, the strength of the back surface layer 3 itself decreases, which is not preferable.

The modified polyolefin resin having a hydroxyl group contained in the back surface layer 3 is further acrylic-modified by further adding a (meth)acrylic acid-based monomer to improve the solubility in a polar solvent and the adhesiveness with a polyurethane foaming agent. It can also be improved.
As a method of acrylic-modifying a modified polyolefin resin having a hydroxyl group, for example, after reacting an unsaturated bond-containing compound having a functional group that reacts with a modified portion of a modified polyolefin resin having a hydroxyl group, and after introducing a double bond And a method of graft copolymerizing a (meth)acrylic acid-based monomer.

The modified polyolefin resin having a hydroxyl group contained in the back surface layer 3 of the present embodiment can be produced by a known method such as a melting method or a solution method.
As the modified polyolefin resin having a hydroxyl group, a commercially available product may be used, and examples thereof include Unisutol P801 (trade name, solid content hydroxyl value: 40 mgKOH/g) and Unisutol P901 (trade name, solid) manufactured by Mitsui Chemicals, Inc. Hydroxyl group value: 50 mgKOH/g), polytail (trade name, solid content hydroxyl value: 45 to 50 mgKOH/g) manufactured by Mitsubishi Chemical Co., and the like.

The non-silicone release agent contained in the back surface layer 3 is not particularly limited, and examples thereof include long-chain alkyl resin, fluorine resin, acrylic resin, polyolefin resin, and alkyd resin.
In the present embodiment, since the back surface layer 3 contains the non-silicone release agent, the adhesive layer 4 and the back surface layer 3 are less likely to adhere to each other, as compared with the case where the back surface layer 3 does not contain the non-silicone release agent. The rewinding force of the adhesive tape 1 can be reduced.
When a non-silicone release agent is contained in addition to the modified polyolefin resin having a hydroxyl group, the content of the non-silicone release agent varies depending on the type of the non-silicone release agent. It may be appropriately determined in consideration of the balance of adhesion. For example, when the non-silicone release agent is a long chain alkyl resin, the mass ratio of the modified polyolefin resin having a hydroxyl group and the long chain alkyl resin is preferably in the range of 85/15 to 99/1.

The thickness of the back surface layer 3 is preferably in the range of 0.05 μm or more and 10 μm or less. When the thickness of the back surface layer 3 is less than 0.05 μm, the back surface layer 3 and the pressure sensitive adhesive layer 4 are bonded and integrated with each other in a state where the pressure sensitive adhesive tape 1 is wound, and the pressure sensitive adhesive tape 1 cannot be rewound. There is a risk.
On the other hand, when the thickness of the back layer 3 exceeds 10 μm, the back layer 3 may be peeled off from the base material 2 by the pressure-sensitive adhesive layer 4 when the pressure-sensitive adhesive tape 1 is rewound. If the thickness of the back surface layer 3 exceeds 10 μm, the material cost tends to increase. Furthermore, when the thickness of the back surface layer 3 exceeds 10 μm, blocking may occur depending on the material forming the back surface layer 3.

[Adhesive layer 4]
The pressure-sensitive adhesive layer 4 of the present embodiment is composed of at least one selected from urethane-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, acrylic urethane-based pressure-sensitive adhesives, and silicone-based pressure-sensitive adhesives.
Among these, from an acrylic urethane-based pressure-sensitive adhesive or a urethane-based pressure-sensitive adhesive, which can fix a refrigerant pipe or the like that is an adherend of the pressure-sensitive adhesive tape 1 and does not have an excessively high rewinding force when rewinding the pressure-sensitive adhesive tape 1. It is preferable to use one selected from the above for the pressure-sensitive adhesive layer 4, and it is more preferable to use an acrylic urethane-based pressure-sensitive adhesive.

<Urethane adhesive>
The structure of the urethane-based pressure-sensitive adhesive used in the pressure-sensitive adhesive layer 4 is not particularly limited. For example, (1) a pressure-sensitive adhesive containing a polyol as a main component and a polyisocyanate compound as a curing component (crosslinking agent). Agent composition, or (2) a pressure-sensitive adhesive composition containing as a main component a urethane prepolymer obtained by subjecting a polyol and a polyisocyanate compound to a urethane reaction in advance and containing a polyisocyanate compound or the like as a curing component (crosslinking agent) Consists of. The above urethane-based pressure-sensitive adhesive can be used by adding a fatty acid ester or the like as a plasticizer for adjusting hardness, if necessary.

(Polyol)
The polyol used in the urethane adhesive composition of the above (1) and (2) is not particularly limited, but examples thereof include polyether polyol, polyester polyol, polycaprolactone polyol, and polycarbonate polyol. it can. These may be used alone or in combination of two or more.

(Polyisocyanate compound)
The polyisocyanate compound used in the urethane pressure-sensitive adhesive composition of the above (1) and (2) is not particularly limited, but examples thereof include aromatic polyisocyanate, aliphatic polyisocyanate, araliphatic polyisocyanate, Examples thereof include alicyclic polyisocyanate. These may be used alone or in combination of two or more.

As the aromatic polyisocyanate, 1,3-phenylene diisocyanate, 4,4′-diphenyl isocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate Diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4',4' '-Triphenylmethane triisocyanate and the like can be mentioned.

As the aliphatic polyisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2, 4,4-trimethylhexamethylene diisocyanate and the like can be mentioned.

Examples of araliphatic polyisocyanates include ω,ω′-diisocyanate-1,3-dimethylbenzene, ω,ω′-diisocyanate-1,4-dimethylbenzene, ω,ω′-diisocyanate-1,4-diethylbenzene, 1 , 4-tetramethylxylylene diisocyanate, 1,3-tetramethylxylylene diisocyanate, etc. can be mentioned.

As the alicyclic polyisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4 -Cyclohexanediisocyanate, methyl-2,6-cyclohexanediisocyanate, 4,4'-methylenebis(cyclohexylisocyanate), 1,4-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, etc. may be mentioned. it can.

Examples of the polyisocyanate compound further include the trimethylolpropane adduct of the above polyisocyanate compound, a trimer having an isocyanurate ring, and a burette body reacted with water. As such a polyisocyanate compound, a commercially available product can be used, and specifically, Coronate L, Coronate L-55E, Coronate L-45E, Coronate HL, Coronate HX manufactured by Tosoh Corp. Name), and a curing agent L-45 (trade name) manufactured by Soken Chemical Industry Co., Ltd. are used, but the curing agent is not particularly limited thereto.

In addition, regarding the urethane-based pressure-sensitive adhesive composition of the above (2), in place of the polyisocyanate compound, according to the functional group of the urethane prepolymer, an epoxy-based, metal chelate-based, polyfunctional acrylate-based, etc. One or a mixture of two or more agents may be used as a curing component (crosslinking agent).

(Fatty acid ester)
The fatty acid ester used for adjusting the hardness of the urethane-based pressure-sensitive adhesive composition is not particularly limited, but for example, methyl laurate, methyl myristate, methyl palmitate, methyl stearate, methyl oleate, Methyl erucate, butyl laurate, butyl stearate, isopropyl myristate, isopropyl palmitate, octyl palmitate, octyl stearate, octyl oleate, isooctyl stearate and the like can be mentioned.

(solvent)
The urethane resin is usually prepared by dissolving the above-mentioned polyurethane polyol, isocyanate-based crosslinking agent, fatty acid ester and the like in a solvent.
Examples of the solvent used for preparing the urethane resin include toluene, benzene, tetrahydrofuran, ethyl acetate, butyl acetate, methyl ethyl ketone, acetone, and mixed solvents thereof.

<Acrylic adhesive>
The acrylic pressure-sensitive adhesive used in the pressure-sensitive adhesive layer 4 includes a copolymer of a (meth)acrylic acid alkyl ester monomer and a polar group-containing monomer, and a cross-linking agent. When the acrylic pressure-sensitive adhesive is used, the pressure-sensitive adhesive layer 4 is formed by drying the solvent (for example, toluene, ethyl acetate, xylene, n-hexane, etc.) or water in the acrylic pressure-sensitive adhesive. Alternatively, a (meth)acrylic acid alkyl ester monomer, a polar group-containing monomer and a polyfunctional acrylate in the acrylic pressure-sensitive adhesive may be added to a photopolymerization initiator (for example, Irgacure 184, Irgacure 651, Irgacure manufactured by BASF Japan Ltd.). 369, Irgacure 819 (both are trade names), Chivacure TPO, Chivacure 107, Chivacure 173, Chivacure 173, Chivacure 1256 (both are trade names) manufactured by Caytec Co., Ltd. are added in an amount of 0.001 to 5.0 parts by weight, and ultraviolet rays (UV). ) By polymerizing, the pressure-sensitive adhesive layer 4 is formed.

The copolymer of the (meth)acrylic acid alkyl ester monomer and the polar group-containing monomer includes, for example, a copolymer of 2-ethylhexyl acrylate and acrylic acid, isooctyl acrylate and 2-hydroxy methacrylate. A copolymer with ethyl, a terpolymer of butyl acrylate, acrylic acid and 2-hydroxyethyl methacrylate, and the like are used, but not particularly limited thereto.

((Meth)acrylic acid alkyl ester monomer)
Examples of the above-mentioned (meth)acrylic acid alkyl ester monomer include ethyl group, propyl group, butyl group, pentyl group, hexyl group, 2-ethylhexyl group, octyl group, isooctyl group, nonyl group, isononyl group, decyl group. Typical examples thereof include esters of (meth)acrylic acid having an alkyl group having 20 or less carbon atoms, and the like. The above-mentioned (meth)acrylic acid alkyl ester is used alone or in combination of two or more kinds.

(Monomer containing polar group)
Examples of the polar group-containing monomer described above include acrylic acid, methacrylic acid, itaconic acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl acrylate, acrylonitrile, and acrylic acid-β-carboxyl. Examples of the polymerizable unsaturated monomer having a polar group such as a carboxyl group, a hydroxyl group and an amino group in the molecule, represented by ethyl (β-CEA), methacrylonitrile, N-vinyl-2-pyrrolidone and the like. Be done.

(Tackifier)
The tackifier for the acrylic pressure-sensitive adhesive layer is a highly weatherable hydrogenated rosin resin (fully hydrogenated rosin resin), aliphatic fully saturated hydrocarbon resin, hydrogenated terpene resin (fully hydrogenated terpene resin) or A silane coupling agent, specifically, Pine Crystal KE-100, Pine Crystal KE-311, Pine Crystal KE-359, Pine Crystal KE-604, Alcon P-70, Alcon P manufactured by Arakawa Chemical Industry Co., Ltd. -100, Archon P-115, Archon P-125, Archon P-140 (all are trade names), Yasuhara Chemical's Clearon P-85, Clearon P-105, Clearon P-115, Clearon P-125, Clearon M. -105, CLEARON K-100, CLEARON K-110 (all are trade names) and silane coupling agents Z-6011, Z-6020, Z-6050, Z-6041, Z-6044, manufactured by Toray Dow Corning Co., Ltd. Z-6920, Z-6075, Z-6300, Z-6825, Z-6033, Z-6062, Z-6860 (all are trade names) are used, but are not particularly limited to these. ..

(Crosslinking agent)
The cross-linking agent for the acrylic pressure-sensitive adhesive layer is, for example, a compound having two or more functional groups such as an isocyanate group (polyisocyanate) and a glycidyl group (epoxy resin) in the molecule, an isocyanate group (polyisocyanate)-containing compound. Which has a polyurethane skeleton with two or more functional groups such as isocyanate at the end, or a polyfunctional acrylate such as 1,6-hexanediol diacrylate or triethylene glycol diacrylate, Alternatively, a metal chelate compound is present. Specifically, Coronate L, Coronate L-55E, Coronate L-45E (all are trade names) manufactured by Tosoh Corporation, TETRAD-C, TETRAD-X (all are trade names) manufactured by Mitsubishi Gas Chemical Co., Inc., Soken Chemical Hardener L-45, hardener E-AX, hardener E-5C, hardener E-100X, hardener M-5, hardener M-5A (all are trade names), Shin-Nakamura Chemical Co., Ltd. A-HD-NA-1000 (trade name) manufactured by and the like is used, but it is not particularly limited thereto.

<Acrylic urethane adhesive>
The structure of the acrylic urethane-based pressure-sensitive adhesive used in the pressure-sensitive adhesive layer 4 is not particularly limited. For example, (1) (meth)acrylic-based polyol is a main component, and a polyisocyanate compound is a curing component (cross-linked). As an agent), (2) (meth)acrylic urethane prepolymer obtained by subjecting a (meth)acrylic polyol and a polyisocyanate compound to a urethane reaction in advance as a main component, and a polyisocyanate compound, etc. Examples thereof include those comprising a pressure-sensitive adhesive composition contained as a curing component (crosslinking agent). Further, the acrylic urethane-based pressure-sensitive adhesive in the invention of the present application has (3) a mixture of the main component exemplified in the description of the urethane-based pressure-sensitive adhesive and the main component exemplified in the description of the acrylic-based pressure-sensitive adhesive as a main component, A polyisocyanate compound etc. can be included as a curing component (crosslinking agent), and finally the main component of the urethane adhesive and the main component of the acrylic adhesive can be crosslinked through the curing component (crosslinking agent). It may be composed of a different adhesive composition.
When the acrylic urethane-based pressure-sensitive adhesive is used, the solvent in the acrylic urethane-based pressure-sensitive adhesive (for example, toluene, ethyl acetate, xylene, n-hexane, etc.) is dried to form the pressure-sensitive adhesive layer 4.

((Meth)acrylic polyol)
The (meth)acrylic polyol used in the acrylic urethane-based pressure-sensitive adhesive composition of the above (1) and (2) is not particularly limited, but for example, (meth)acrylic having at least a hydroxyl group as a polar group. Examples include (meth)acrylic polyols obtained by polymerizing a system monomer to introduce a hydroxyl group, and (meth)acrylic polymer polyols obtained by modifying a (meth)acrylic polymer to introduce at least a hydroxyl group as a polar group. Be done. Usually, a (meth)acrylic polyol having a hydroxyl group introduced by polymerizing a (meth)acrylic monomer having a hydroxyl group is preferably used. Specifically, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl acrylate, polyoxyethylene (meth)acrylate, polyoxypropylene (meth)acrylate, caprolactone-modified (meth) One obtained by copolymerizing one or more kinds of hydroxyl group-containing (meth)acrylic monomers such as acrylate with another copolymerizable monomer can be used.

Examples of the other copolymerizable monomer to be copolymerized with the hydroxyl group-containing (meth)acrylic monomer include aromatic vinyl monomers such as styrene, α-methylstyrene, p-tert-butylstyrene, and vinyltoluene. , Methyl(meth)acrylate, ethyl(meth)acrylate, n-propyl(meth)acrylate, iso-propyl(meth)acrylate, n-butyl(meth)acrylate, t-butyl(meth)acrylate, iso-butyl(meth) ) Acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate and other (meth)acrylates, maleic acid , Diesters of unsaturated dicarboxylic acids such as fumaric acid or itaconic acid with monohydric alcohols, vinyl esters such as vinyl acetate, vinyl benzoate, vinyl propionate and vinyl laurate, and vinyl ethers.

As the main component of the urethane-based pressure-sensitive adhesive used in the acrylic urethane-based pressure-sensitive adhesive composition of (3), the same polyols and urethane prepolymers as exemplified in the description of the urethane-based pressure-sensitive adhesive can be used. ..
Further, as the main components of the acrylic pressure-sensitive adhesive used in the acrylic urethane pressure-sensitive adhesive composition of (3), the (meth)acrylic acid alkyl ester monomer and polar group exemplified in the description of the acrylic pressure-sensitive adhesive are used. The same thing as a copolymer with a content monomer can be used.

(Mixing ratio)
In the acrylic urethane-based pressure-sensitive adhesive composition of the above (3) used for the pressure-sensitive adhesive layer 4, the mass ratio of the main component of the urethane-based pressure-sensitive adhesive (A) and the main component of the acrylic-based pressure-sensitive adhesive (B) ( A/B) varies depending on the desired characteristics, but is preferably in the range of 90/10 to 10/90, and more preferably in the range of 80/20 to 20/80.

(Polyisocyanate compound)
As the polyisocyanate compound used in the acrylic urethane-based pressure-sensitive adhesive composition of the above (1), (2), and (3), the same polyisocyanate compound as exemplified in the description of the urethane-based pressure-sensitive adhesive can be used. ..

Regarding the acrylic urethane-based pressure-sensitive adhesive compositions of (2) and (3) above, instead of the polyisocyanate compound, the epoxy-based pressure-sensitive adhesive exemplified in the explanation of the acrylic pressure-sensitive adhesive according to the functional group of the main component, It is also possible to use one or a mixture of two or more crosslinking agents such as a metal chelate type as a curing component (crosslinking agent). Furthermore, for example, a melamine compound such as methylated trimethylolmelamine and butylated hexamethylolmelamine can be used as a curing component (crosslinking agent).

(Additive)
The acrylic urethane-based pressure-sensitive adhesive composition used for the pressure-sensitive adhesive layer 4 may contain additives such as a tackifier, a filler, a colorant, an ultraviolet absorber, an antioxidant, an antifoaming agent, and a light stabilizer, if necessary. May be included.

<Silicone adhesive>
The constitution of the silicone-based pressure-sensitive adhesive composition used for the pressure-sensitive adhesive layer 4 is not particularly limited, but for example, (1) a pressure-sensitive adhesive composition containing an addition reaction type silicone-based pressure-sensitive adhesive as a main component, (2) A pressure-sensitive adhesive composition containing a peroxide-curable silicone-based pressure-sensitive adhesive as a main component. These (1) and (2) may be used alone or in combination.

The addition reaction type silicone pressure-sensitive adhesive used in the addition reaction type silicone pressure-sensitive adhesive composition of the above (1) is not particularly limited, and examples thereof include KR3700, KR3701, X- manufactured by Shin-Etsu Chemical Co., Ltd. 40-3237-1, X-40-3240, X-40-3291-1, X-40-3229, X-40-3270, X-40-3306 (all are trade names) and Momentive Performance Materials. TSR1512, TSR1516, XR37-B9204 (all of which are product names) manufactured by Toray Dow Corning, and SD4584, SD4585, SD4560, SD4570, SD4600PFC, SD4593 (all of product names) manufactured by Toray Dow Corning can be used.

The cross-linking agent for cross-linking the addition reaction type silicone adhesive is not particularly limited, but for example, X-92-122 (trade name) manufactured by Shin-Etsu Chemical Co., Ltd. or Momentive Performance Materials such as CR50 (trade name) and Toray Dow Corning BY24-741 (trade name) can be used.

Examples of the peroxide-curable silicone-based pressure-sensitive adhesive used in the above-mentioned (2) peroxide-curable silicone-based pressure-sensitive adhesive composition include Shin-Etsu Chemical Co., Ltd.'s KR100 and KR101-10 (both are trade names), Momentive Performance Materials YR3340, YR3286, PSA610-SM, XR37-B6722 (all are brand names), Toray Dow Corning SH4280 (brand name), etc. can be used.

The cross-linking agent for cross-linking the peroxide-curable silicone-based pressure-sensitive adhesive is not particularly limited, and examples thereof include benzoyl peroxide, dicumyl peroxide, and 2,5-dimethyl-2,5-di( t-butylperoxy)hexane, 1,1'-di-t-butylperoxy-3,3,5-trimethylenecyclohexane, 1,3-di-(t-butylperoxy)-diisopropylbenzene and the like.

The pressure-sensitive adhesive layer 4 preferably has a thickness of 10 μm or more, and more preferably 50 μm or more. When the thickness of the pressure-sensitive adhesive layer 4 is less than 10 μm, the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer 4 tends to be low, and the pressure-sensitive adhesive force of the pressure-sensitive adhesive tape 1 to the adherend may be insufficient.
Furthermore, the thickness of the pressure-sensitive adhesive layer 4 is preferably 100 μm or less, more preferably 80 μm or less. If the thickness of the pressure-sensitive adhesive layer 4 is thicker than 100 μm, the pressure-sensitive adhesive that constitutes the pressure-sensitive adhesive layer 4 in the pressure-sensitive adhesive tape 1 may stick out from the peripheral edge of the substrate 2. In this case, the appearance of the pressure-sensitive adhesive tape 1 may deteriorate or the pressure-sensitive adhesive layer 4 may easily deteriorate.
Further, in consideration of the relationship with the base material 2, the thickness of the pressure-sensitive adhesive layer 4 is preferably about the same as the thickness of the base material 2.

As described above, the pressure-sensitive adhesive tape 1 of the present embodiment includes the base material 2 made of aluminum foil, and the back surface layer 3 laminated on one surface of the base material 2 and containing the modified polyolefin resin having a hydroxyl group. And a pressure-sensitive adhesive layer 4 laminated on the other surface of the substrate 2 and made of at least one of an acrylic pressure-sensitive adhesive, an acrylic urethane pressure-sensitive adhesive, a urethane pressure-sensitive adhesive and a silicone pressure-sensitive adhesive.

With such a configuration, in the pressure-sensitive adhesive tape 1 of the present embodiment, the back surface layer 3 has releasability with respect to the pressure-sensitive adhesive layer 4 and adhesiveness with respect to the polyurethane foam. Has a function to improve.
Thereby, when the adhesive tape 1 is used for fixing the refrigerant pipe in the refrigerator, the adhesion between the back surface layer 3 of the adhesive tape 1 and the polyurethane foam becomes good. As a result, the adhesive tape 1 and the polyurethane foam are prevented from peeling off during use of the refrigerator, and problems such as noise caused by vibration of the compressor of the refrigerator or the motor of the cooling fan are suppressed. ..

Furthermore, in the pressure-sensitive adhesive tape 1 of the present embodiment, even when the pressure-sensitive adhesive tape 1 is wound into a roll without using a release liner, the pressure-sensitive adhesive layer 4 and the back surface layer 3 are bonded and integrated. Is suppressed. As a result, it is possible to prevent the force (rewinding force) required for rewinding the pressure-sensitive adhesive tape 1 wound into a roll from becoming excessively large, and when the pressure-sensitive adhesive tape 1 is used, the pressure-sensitive adhesive tape 1 cannot be rewound. The occurrence of the problem is suppressed.

Moreover, in the pressure-sensitive adhesive tape 1 of the present embodiment, it is not necessary to use a release liner or the like in order to prevent the pressure-sensitive adhesive layer 4 and the back surface layer 3 from being integrated. Therefore, the amount of waste can be reduced as compared with the case where a release liner is used, which leads to resource saving. Moreover, since the work of peeling the adhesive tape 1 from the release liner when using the adhesive tape 1 can be omitted, the usability of the adhesive tape 1 is improved.

[Method for producing adhesive tape 1]
Next, an example of a method of manufacturing the adhesive tape 1 of the present embodiment will be described. The adhesive tape 1 is manufactured, for example, by forming the adhesive layer 4 on the base material 2 and then forming the back layer 3 on the surface of the base material 2 opposite to the surface on which the adhesive layer 4 is formed. be able to.

Specifically, first, an adhesive composition that constitutes the adhesive layer 4 is prepared. This pressure-sensitive adhesive composition is applied to one surface of the base material 2 made of aluminum foil using a comma coater or the like so that the thickness after drying becomes uniform. Next, the pressure-sensitive adhesive composition applied to the base material 2 is heated and dried at a predetermined temperature to form the pressure-sensitive adhesive layer 4. Then, the release film is attached to the pressure-sensitive adhesive layer 4, rolled up, and aged under predetermined conditions.

Subsequently, the modified polyolefin resin having a hydroxyl group that constitutes the back surface layer 3 is applied to the surface of the base material 2 opposite to the surface on which the pressure-sensitive adhesive layer 4 is formed (the other surface) with a gravure roll or the like. Next, the modified polyolefin resin having a hydroxyl group applied to the base material 2 is heated and dried at a predetermined temperature to form the back surface layer 3. After that, the back surface layer 3 is wound so that it is on the outer peripheral side. The release film attached to the pressure-sensitive adhesive layer 4 is removed by peeling during the winding. The peeling film that has been peeled off can be reused.

Alternatively, the adhesive tape 1 may be manufactured by reversing the order of forming the adhesive layer 4 and the back surface layer 3. Specifically, a modified polyolefin resin having a hydroxyl group that constitutes the back surface layer 3 is applied to one surface of the base material 2 made of aluminum foil by a gravure roll or the like. Next, the modified polyolefin resin having a hydroxyl group applied to the base material 2 is heated and dried at a predetermined temperature to form the back surface layer 3. Then, the base material 2 on which the back surface layer 3 is formed is wound so that the back surface layer 3 is on the outer peripheral side.

Then, the adhesive composition which comprises the adhesive layer 4 is produced. This adhesive composition is applied to the surface of the base material 2 opposite to the surface on which the back surface layer 3 is formed (the other surface) using a comma coater or the like so that the thickness after drying becomes uniform. .. Next, the pressure-sensitive adhesive composition applied to the base material 2 is heated and dried at a predetermined temperature to form the pressure-sensitive adhesive layer 4. Then, the base material 2 on which the back surface layer 3 and the pressure-sensitive adhesive layer 4 are formed is wound so that the back surface layer 3 is on the outer peripheral side, and is aged under a predetermined condition. At this time, a release film may be attached to the pressure-sensitive adhesive layer 4 and wound if necessary. When a release film is used, it may be rewound after aging to remove the release film. The peeling film that has been peeled off can be reused.
Through the above steps, the adhesive tape 1 of the present embodiment is obtained in which the back layer 3 is laminated on one surface of the base material 2 made of aluminum foil and the adhesive layer 4 is laminated on the other surface.

The method for manufacturing the adhesive tape 1 is not limited to the above method. For example, the base material 2 may be simultaneously coated with the modified polyolefin resin having a hydroxyl group that forms the back surface layer 3 and the pressure-sensitive adhesive composition that forms the pressure-sensitive adhesive layer 4.

Next, the present invention will be described in more detail based on examples. The present invention is not limited to the examples below.
1. Preparation of adhesive tape 1 (Example 1)
Acrylic urethane adhesive "LMS-102" (trade name, manufactured by Fujikura Kasei Co., solid content concentration: 30% by weight) is added to 100 parts by weight of an isocyanate crosslinking agent "Coronate L-55E" (trade name, manufactured by Tosoh Corporation, solid (Partial concentration: 55% by weight) 2 parts by weight were added and stirred to prepare an adhesive composition solution a. Next, the pressure-sensitive adhesive composition solution a is applied to the surface of the base material 2 made of a soft aluminum foil (thickness 50 μm) according to JIS H 4160 using a comma coater so that the thickness after drying is 20 μm. did.
Subsequently, the pressure-sensitive adhesive composition solution a applied to the base material 2 is heated at a temperature of 110° C. for 180 seconds to dry the pressure-sensitive adhesive composition solution a, whereby the pressure-sensitive adhesive layer 4 is laminated on the base material 2. A laminated body was obtained. Then, the release-treated surface of the single-sided silicone release-treated polyester (release PET) film was attached to the surface of the pressure-sensitive adhesive layer 4 of the laminate and wound up, and aged at 40° C. for 72 hours.

Subsequently, 25 parts by weight of a modified polyolefin resin having a hydroxyl group, “UNISTOL P801” (trade name, manufactured by Mitsui Chemicals, Inc., solid content concentration: 16% by weight, hydroxyl value of solid content: 40 mgKOH/g) was added to 475 parts by weight of toluene. It was made to melt|dissolve and the resin solution A was produced.
Next, while rewinding the wound laminate, the resin solution A was applied to the surface of the base material 2 opposite to the surface on which the pressure-sensitive adhesive layer 4 was formed, using a bar coater. Subsequently, the resin solution A applied on the base material 2 is heated at 110° C. for 2 minutes to dry the resin solution A, and the peeled PET film is peeled and removed immediately before winding. A backing layer 3 having a thickness of 0.08 μm was laminated on one surface of No. 2 and an adhesive layer 4 having a thickness of 20 μm was laminated on the other surface to obtain an adhesive tape 1.

(Example 2)
Hydroxyl group was added to a resin solution prepared by dissolving 0.4 parts by weight of non-silicone release agent "Peeloyl 1010" (trade name, manufactured by Lion Specialty Chemicals Co., Ltd.) in 99.6 parts by weight of a toluene/white gasoline mixed solvent. 25 parts by weight of modified polyolefin resin “UNISTOL P801” (trade name, manufactured by Mitsui Chemicals, Inc., solid content concentration: 16% by weight, solid content hydroxyl value: 40 mgKOH/g) containing is added and stirred to prepare a resin solution B. did.
An adhesive tape 1 was obtained in the same manner as in Example 1 except that the resin solution B was used in place of the resin solution A, and the thickness of the back surface layer 3 was 0.20 μm.

(Example 3)
100 parts by weight of urethane-based adhesive "Olivine SP-205" (trade name, manufactured by Toyochem, solid content concentration: 50% by weight) and isocyanate-based crosslinking agent "Coronate L-55E" (trade name, manufactured by Tosoh Corporation, solid (Partial concentration: 55% by weight) A solution prepared by dissolving 1 part by weight in 2 parts by weight of ethyl acetate was added and stirred to prepare an adhesive composition solution b.
An adhesive tape 1 was obtained in the same manner as in Example 1 except that the adhesive composition solution b was used instead of the adhesive composition solution a.

(Example 4)
Addition reaction type silicone adhesive "SD4580" (trade name, manufactured by Toray Dow Corning, solid content concentration: 60% by weight) is added to 100 parts by weight of addition reaction type silicone adhesive crosslinking agent "BY-24-741. A solution prepared by dissolving 1 part by weight (trade name, manufactured by Toray Dow Corning Co., Ltd.) in 2 parts by weight of toluene was added and stirred to prepare an adhesive composition solution c.
Example 1 was repeated except that the pressure-sensitive adhesive composition solution c was used instead of the pressure-sensitive adhesive composition solution a, the single-sided fluorosilicone release-treated polyester film was used as the release PET film, and the drying temperature was 140°C. The adhesive tape 1 was obtained.

(Example 5)
100 parts by weight of acrylic adhesive "SKDyne 1415" (trade name, manufactured by Soken Chemical Industry Co., Ltd., solid content concentration: 30% by weight) and isocyanate crosslinking agent "curing agent L-45" (trade name, manufactured by Soken Chemical Industry Co., Ltd.) , Solid content concentration: 45% by weight) A solution prepared by dissolving 1 part by weight in 3 parts by weight of ethyl acetate was added and stirred to prepare an adhesive composition solution d.
An adhesive tape 1 was obtained in the same manner as in Example 1 except that the adhesive composition solution a was used instead of the adhesive composition solution a.

(Example 6)
An adhesive tape 1 was obtained in the same manner as in Example 1 except that the thickness of the back surface layer 3 after drying was 0.04 μm.

(Example 7)
An adhesive tape 1 was obtained in the same manner as in Example 1 except that the thickness of the back surface layer 3 after drying was 0.16 μm.

(Example 8)
An adhesive tape 1 was obtained in the same manner as in Example 1 except that a hard aluminum foil (thickness 50 μm) conforming to JIS H 4160 was used as the base material 2.

(Comparative Example 1)
An adhesive tape 1 was obtained in the same manner as in Example 1 except that the back surface layer 3 was not provided on the base material 2.

(Comparative example 2)
Dissolved 18 parts by weight of modified polyolefin resin having an acid group "UNISTOL P802" (trade name, manufactured by Mitsui Chemicals, solid content concentration: 22% by weight, solid content acid value: 55 mgKOH/g) in 482 parts by weight of toluene. Then, a resin solution C was obtained.
An adhesive tape 1 was obtained in the same manner as in Example 1 except that the resin solution C was used instead of the resin solution A.

(Comparative example 3)
100 parts by weight of natural rubber, 75 parts by weight of poly β-pinene resin, 5 parts by weight of mineral oil, and 2 parts by weight of antioxidant were dissolved in 350 parts by weight of toluene to prepare an adhesive composition solution e.
An adhesive tape 1 was obtained in the same manner as in Example 1 except that the adhesive composition solution e was used instead of the adhesive composition solution a.

(Comparative example 4)
The same procedure as in Example 1 was performed except that the back surface layer 3 was formed by thermally laminating a polyolefin resin "Petrosene 203" (trade name, manufactured by Tosoh Corporation) on the base material 2 so that the thickness was 1.8 μm. Thus, adhesive tape 1 was obtained.

2. Evaluation Method Next, the evaluation method of the adhesive tape 1 will be described.
(1) Measurement of rewinding force and evaluation of breakage of the base material 2 at the time of rewinding The low speed rewinding force was measured based on the low speed rewinding force test of JIS Z 0237 (2009). Further, when the low-speed rewinding force was measured, the presence or absence of breakage of the base material 2 at the end of the adhesive tape 1 was confirmed and evaluated. The breakage of the base material 2 was evaluated as "no" when no break was generated at the end of the base material 2, and "present" when the break was generated at the end of the base material 2.

(2) Measurement of Adhesion Force between Back Layer 3 and Polyurethane Foam After adhering a PET film to the pressure-sensitive adhesive layer 4, with the back layer 3 facing upward, put the adhesive tape 1 in a box (internal size: 50 mm (×150 mm×10 mm), the box was filled with a polyurethane foaming agent, and foamed and cured. Then, the cured polyurethane foaming agent (the polyurethane foaming agent after curing is referred to as a polyurethane foam) is taken out, and the peeling force when peeling the adhesive tape 1 from the adhesive layer 4 side in the direction of 180° (the back layer 3 and The adhesion with the polyurethane foam) was measured.

(3) Measurement of adhesive force The adhesive force to a stainless steel plate was measured by the method described in JIS Z 0237 (2009).

3. Evaluation results Subsequently, Tables 1 and 2 show the evaluation results of the adhesive tapes 1 of Examples 1 to 8 and Comparative Examples 1 to 3, respectively.

As shown in Table 1, a base material 2 made of aluminum foil, a back layer 3 containing a polyolefin resin having a hydroxyl group, an acrylic pressure sensitive adhesive, an acrylic urethane pressure sensitive adhesive, a urethane pressure sensitive adhesive and a silicone pressure sensitive adhesive are used. In the pressure-sensitive adhesive tapes 1 of Examples 1 to 8 including the pressure-sensitive adhesive layer 4 containing at least one kind, the rewinding force, the breakage of the base material 2 at the time of rewinding, the adhesive force with the polyurethane foam, and the adhesive force. It was confirmed that good results were obtained in any of the evaluation tests. In particular, it was confirmed that the adhesive tapes 1 of Examples 1 to 3 and 6 to 8 using the acrylic urethane-based adhesive or the urethane-based adhesive as the adhesive had a small rewinding force and were more preferable.

On the other hand, in the pressure-sensitive adhesive tape 1 of Comparative Example 1 in which the back surface layer 3 is not provided on the base material 2, the rewinding force is larger than that of Examples 1 to 8, and the result is that the base material 2 is cut during rewinding. Became.
In the pressure-sensitive adhesive tape of Comparative Example 2 in which the back surface layer 3 contains a modified polyolefin resin having an acid group instead of a polyolefin resin having a hydroxyl group, the adhesive strength with the polyurethane foam was large, but the adhesive layer 4 The adhesion with the back surface layer 3 became too high, and as in Comparative Example 1, the rewinding force increased, and the base material 2 was cut during the rewinding.

Furthermore, in the pressure-sensitive adhesive tape 1 of Comparative Example 3 in which the pressure-sensitive adhesive layer 4 contains a rubber-based pressure-sensitive adhesive, the adhesive force between the pressure-sensitive adhesive layer 4 and the back surface layer 3 becomes too high, and the rewinding force becomes large. The result is that the material 2 is cut.
Furthermore, in the pressure-sensitive adhesive tape 1 of Comparative Example 4 in which the back surface layer 3 contains an unmodified polyolefin-based resin instead of a polyolefin-based resin having a hydroxyl group, the unwinding force was low and the film could be easily unwound, but polyurethane foaming was performed. It was confirmed that the adhesiveness to the body was low and it was not suitable for the purpose of fixing the refrigerant pipe of the refrigerator.

1... Adhesive tape, 2... Base material, 3... Back layer, 4... Adhesive layer

Claims (4)

A base material made of aluminum,
Laminated on one surface of the substrate, a back layer containing a modified polyolefin resin having a hydroxyl group,
The laminated on the other surface of the substrate, seen containing an acrylic urethane pressure-sensitive adhesives, comprising at least one adhesive urethane pressure-sensitive adhesives do we selected pressure-sensitive adhesive layer,
The modified polyolefin resin having a hydroxyl group has a hydroxyl value of 40 mgKOH/g to 50 mgKOH/g, and the skeletal polyolefin resin is one selected from polypropylene or polypropylene-α-olefin copolymer,
An adhesive tape having a rewinding force of 0.95 N/10 mm to 1.60 N/10 mm . The pressure-sensitive adhesive tape according to claim 1, wherein the back layer further contains a non-silicone release agent. The adhesive tape according to claim 1, wherein the base material is made of a soft aluminum foil. The pressure-sensitive adhesive tape according to claim 1, wherein the pressure-sensitive adhesive layer is wound so as to overlap the back surface layer without using a release liner.

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