JP2008031196A - Metallic foil adhesive tape and refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic foil adhesive tape having good adhesion on a rear polyurethane component and excellent in workability at time of rewinding. <P>SOLUTION: In the metallic foil adhesive tape, an adhesive layer is formed on one surface of a metallic foil and a rear face-treating layer is formed on the other surface and the adhesive layer is formed of an acrylic adhesive composition containing an acrylic polymer having ≤0°C glass transition temperature as a main component and the rear surface-treating layer is formed of a rear surface-treating agent composition containing a silicone-based releasing agent containing a silicone component having a diorganosiloxane skeleton as a main component and an acrylic polymer. A condensation reaction type silicone-based release agent can suitably be used as the silicone-based release agent in the rear surface-treating agent composition for forming the rear surface-treating layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a metal foil adhesive tape and a refrigerator in which the metal foil adhesive tape is used.

  Conventionally, a metal foil adhesive tape has been used to fix a heat radiating tube of a refrigerator. The purpose is to exhibit the function of radiating heat using the thermal conductivity of the metal foil in addition to the function of fixing. When using such a metal foil pressure-sensitive adhesive tape, a rewinding operation occurs. Generally, in terms of workability, it is better that this rewinding force is small. Then, a mold release process (peeling process) is performed (see Patent Documents 1 and 2).

  On the other hand, in order not to let the heat inside the refrigerator escape to the outside, a two-component curable hard polyurethane is used. This polyurethane is used so as to fill a space including a portion where a heat radiating tube is fixed by a metal foil adhesive tape. Specifically, a method is generally employed in which a heat-radiating tube is fixed with a metal foil adhesive tape and assembled into a refrigerator, and then a two-component curable hard polyurethane is injected in liquid form. Therefore, it is required that the polyurethane component adheres to the back surface of the metal foil adhesive tape. If this adhesion is weak (low), it peels off over time, causing a problem that not only the box strength is lowered but also the appearance is deteriorated.

Japanese Patent Laid-Open No. 5-311131 JP-A-10-292162

  Thus, the metal foil pressure-sensitive adhesive tape is required to be rewound with excellent workability and to have good adhesion (urethane adhesion) to the polyurethane component on the back surface. However, with the conventional back surface treatment agent, it has been difficult to achieve both excellent adhesion (removability) to the pressure-sensitive adhesive layer and adhesion to the polyurethane component at an excellent level. Specifically, for example, when the back surface treatment agent described in JP-A-5-311131 is used, the adhesiveness to the pressure-sensitive adhesive layer is low and the workability at the time of rewinding is good. On the other hand, when the back treatment agent described in JP-A-10-292162 is used, the adhesion to the polyurethane component is good, but the work when rewinding due to the compatibility with the adhesive layer, etc. The performance is lowered and satisfactory results are not obtained.

  Accordingly, an object of the present invention is to provide a metal foil pressure-sensitive adhesive tape having good adhesion to the polyurethane component on the back surface and excellent workability during rewinding, and a refrigerator using the metal foil pressure-sensitive adhesive tape. There is.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have formed a pressure-sensitive adhesive layer of a metal foil pressure-sensitive adhesive tape with a characteristic acrylic pressure-sensitive adhesive composition, and a back treatment layer constituting the back surface. It has been found that when it is formed with a backside treatment composition containing a specific silicone release agent and an acrylic polymer, the adhesion to the polyurethane component on the backside can be enhanced while maintaining the workability during rewinding. The present invention has been completed based on these findings.

  Although the mechanism by which this effect can be achieved is not clear, in addition to the excellent releasability of certain silicone release agents, acrylic polymers (particularly in acrylic polymers) contained in the back treatment layer It is interpreted that the functional group of (ii) worked well on the adhesion to the polyurethane component.

  That is, the present invention is a metal foil pressure-sensitive adhesive tape having a configuration in which a pressure-sensitive adhesive layer is formed on one surface of a metal foil and a back treatment layer is formed on the other surface, and the pressure-sensitive adhesive layer has a glass transition A silicone release agent which is formed of an acrylic pressure-sensitive adhesive composition whose main component is an acrylic polymer having a temperature of 0 ° C. or less, and whose back treatment layer has a silicone component of a diorganosiloxane skeleton as a main component; The metal foil pressure-sensitive adhesive tape is formed of a back surface treatment composition containing an acrylic polymer.

  In the metal foil pressure-sensitive adhesive tape of the present invention, the acrylic pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer further includes an acrylic oligomer having a weight average molecular weight of 3000 or more and less than 20000, and / or a tackifier resin. It is preferable to include. In the back treatment composition for forming the back treatment layer, the silicone release agent is preferably a condensation reaction type silicone release agent, and the acrylic polymer is preferably an acrylic polymer containing a functional group. It is.

  The present invention also provides a refrigerator in which a radiator tube is fixed by a metal foil adhesive tape, wherein the metal foil adhesive tape is used as the metal foil adhesive tape. .

  According to the metal foil pressure-sensitive adhesive tape of the present invention, since it has the above-described configuration, the adhesiveness to the polyurethane component on the back surface is good, and the workability at the time of rewinding is excellent. Therefore, the metal foil pressure-sensitive adhesive tape of the present invention is useful as a metal foil pressure-sensitive adhesive tape used when fixing a heat radiating tube in a refrigerator.

[Back treatment layer]
In the metal foil pressure-sensitive adhesive tape of the present invention, the back surface treatment agent composition for forming the back surface treatment layer contains a silicone release agent mainly composed of a silicone component of a diorganosiloxane skeleton and an acrylic polymer. . The backside treatment composition can be used alone or in combination of two or more.

(Silicone-based release agent)
The silicone-based release agent contains a silicone component having a diorganosiloxane skeleton as a main component. As such a silicone-based release agent, a silicone-based release agent that can be cured by a curing reaction (particularly, a curing reaction by application of heat, ionizing radiation, etc.) to form a peelable film (peelable cured film). A release agent (a curable silicone release agent) can be suitably used. Examples of the curable silicone release agent include a thermosetting silicone release agent and an ionizing radiation curable silicone release agent, and a thermosetting silicone release agent is preferable. In addition, a silicone component or a silicone type release agent can be used individually or in combination of 2 or more types.

  The thermosetting silicone release agent is a type of silicone release agent that is cured by heat, for example, an addition reaction type silicone type that is cured by an addition reaction type curing reaction to form a peelable cured film. Examples of the release agent include a condensation reaction type silicone release agent that cures by a condensation reaction type curing reaction to form a peelable cured film, and a condensation reaction type silicone release agent is preferable.

  Such a condensation reaction type silicone release agent usually has (a) a silicone component having hydroxysilyl groups (SiOH groups) at both ends of the molecular chain of the diorganosiloxane skeleton, and (b) a diorganosiloxane skeleton. A silicone component having two or more hydrogen atoms bonded to a hydrocarbon atom (alkoxy group, aryloxy group, cycloalkyloxy group, etc.) or silicon atom bonded to a silicon atom in the molecule of the molecular chain, and if necessary (C) a condensation catalyst.

  As the silicone component (a) having hydroxysilyl groups at both ends of the molecular chain of the diorganosiloxane skeleton (sometimes referred to simply as “(a) component”), polydimethyl having both ends modified with hydroxysilyl groups Siloxane (terminal hydroxyl group-modified polydimethylsiloxane) can be preferably used.

  In addition, the silicone component (b) (simply referred to as “component (b)”) having two or more hydrocarbon oxy groups bonded to silicon atoms or two hydrogen atoms bonded to silicon atoms in the molecular chain of the diorganosiloxane skeleton. As a polydimethylsiloxane having two or more alkoxysilyl groups (methoxy group, ethoxy group, propoxy group, butoxy group, etc.) in the side chain of the molecular chain of the dimethylsiloxane skeleton (side chain alkoxy-modified) Polydimethylsiloxane) can be preferably used, and polydimethylsiloxane having two or more methoxy groups in the side chain of the molecular chain of the dimethylsiloxane skeleton (side chain methoxy-modified polydimethylsiloxane) is particularly preferable.

  The condensation catalyst (c) is not particularly limited and can be appropriately selected from known condensation catalysts, but tin-based condensation catalysts such as dibutyltin diacetate, dioctyltin diacetate, and dioctyltin dilaurate are suitable. It is.

  In the condensation reaction type silicone release agent, the ratio of the component (a) to the component (b) is, for example, (a) component / (b) component (weight ratio) = 70/30 to 99/1 (preferably Can be selected from the range of 80/20 to 95/5). In addition, (b) component is used as a crosslinking agent with respect to (a) component.

  The ratio of the condensation catalyst (c) is selected from the range of 0.1 to 20% by weight (preferably 1 to 10% by weight) with respect to the total amount of the component (a) and the component (b), for example. Can do.

  In the present invention, the condensation reaction type silicone release agent preferably contains ethyl cellulose.

(Acrylic polymer)
The acrylic polymer is a polymer in which one or more (meth) acrylic acid esters (acrylic acid ester, methacrylic acid ester) are used as a monomer main component (monomer main component). As the (meth) acrylic acid ester as the monomer main component, a (meth) acrylic acid alkyl ester is suitable. Examples of (meth) acrylic acid alkyl esters include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, ( Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, neopentyl (meth) acrylate, (meth) acrylic acid Hexyl, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, (meth) acrylic Decyl acid, isodecyl (meth) acrylate, undecyl (meth) acrylate, Meth) (meth) acrylic acid C _1-12 alkyl esters such as dodecyl acrylate are preferred.

  In addition, in the acrylic polymer, (meth) acrylic acid ester is used as a monomer main component, so the proportion of (meth) acrylic acid ester is 50% by weight or more based on the total amount of monomer components. It is important to be used in a proportion, preferably 70% by weight or more (more preferably 80% by weight or more). The upper limit of the ratio of (meth) acrylic acid ester is, of course, 100% by weight or less, preferably 97% by weight or less (more preferably 95% by weight or less).

  As a monomer component constituting such an acrylic polymer, other monomer components that can be copolymerized with (meth) acrylic acid ester (“copolymerizable monomer”) can be used as long as (meth) acrylic acid ester is a main monomer component. 1 type or 2 types or more may be used. As such a copolymerizable monomer component, it can select suitably from well-known monomer components as another monomer component which can be copolymerized with (meth) acrylic acid ester.

  Specifically, examples of the copolymerizable monomer component include (meth) acrylic such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate. Hydroxyalkyl acid, hydroxyl group-containing monomers such as vinyl alcohol and allyl alcohol; (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, isocrotonic acid and other carboxyl group-containing monomers or acid anhydrides thereof (anhydrous) (Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N -Methoxymethyl (meth) acrylamide, Amide monomers such as butoxymethyl (meth) acrylamide; amino group-containing monomers such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate Epoxy group-containing monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate; cyano-containing monomers such as acrylonitrile and methacrylonitrile; N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinyl Pyridine, N-vinyl piperidone, N-vinyl pyrimidine, N-vinyl piperazine, N-vinyl pyrazine, N-vinyl pyrrole, N-vinyl imidazole, N-vinyl oxazole, N-vinyl morpholine, N-vinyl caprolactam, N- (meta ) Acryl Functional group-containing monomer component such as a monomer having a nitrogen atom-containing ring such as Rumoruhorin the like.

  Examples of the copolymerizable monomer component include vinyl ester monomers such as vinyl acetate and vinyl propionate; styrene monomers such as styrene, substituted styrene (α-methylstyrene, and the like), vinyltoluene; ethylene, propylene, and isoprene. Olefin monomers such as butadiene, isobutylene; vinyl chloride, vinylidene chloride; isocyanate group-containing monomers such as 2- (meth) acryloyloxyethyl isocyanate; alkoxy such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate Group-containing monomers: 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, die other than vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether Glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, (poly) propylene glycol Di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin Di (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, divinylbenzene, butyl di (meth) acrylate, hex Polyfunctional monomers such as sildi (meth) acrylate can also be used.

  Examples of copolymerizable monomer components include hydroxyl group-containing monomers such as hydroxyalkyl (meth) acrylate, carboxyl group-containing monomers such as (meth) acrylic acid or acid anhydrides thereof, and amide monomers such as dialkyl (meth) acrylamide. A functional group-containing monomer component is suitable, and in particular, a hydroxyl group-containing monomer can be suitably used. Therefore, an acrylic polymer containing a functional group is suitable as the acrylic polymer, and in particular, an acrylic polymer containing a hydroxyl group can be suitably used.

  The acrylic polymer is prepared by polymerizing the monomer component using a known polymerization method (solution polymerization method, emulsion polymerization method, etc.). In the polymerization, a polymerization initiator can be used as necessary. For example, a polymerization initiator (azo polymerization initiator, used when polymerizing an acrylic polymer in the following acrylic pressure-sensitive adhesive composition) And peroxide polymerization initiators).

  Although it does not restrict | limit especially as a weight average molecular weight of an acryl-type polymer, For example, it can select from the range of 200,000-2 million (preferably 300,000-1 million, More preferably, 300,000-800,000). In addition, the weight average molecular weight of this acrylic polymer is calculated | required similarly to the weight average molecular weight of the acrylic polymer in the following acrylic adhesive composition.

  In the backside treatment composition, the ratio between the silicone release agent and the acrylic polymer is not particularly limited. For example, the silicone release agent / acrylic polymer (weight ratio) = 1 / 0.2 to 1 / It can be selected from the range of 2.5 (preferably 1 / 0.25 to 1/1). When the acrylic polymer is less than 0.2 parts by weight with respect to 1 part by weight of the silicone-based release agent, the urethane adhesiveness is lowered. On the other hand, when it exceeds 2.5 parts by weight, the workability at the time of rewinding is improved. It drops significantly.

  The back surface treatment layer can be formed by applying the back surface treatment agent composition and heating and drying as necessary, or curing by heating or radiation irradiation.

  Although it does not restrict | limit especially as thickness of a back surface treatment layer, For example, it is 0.05-10 micrometers (preferably 0.1-0.6 micrometer, More preferably, 0.2-0.5 micrometer).

[Adhesive layer]
In the metal foil pressure-sensitive adhesive tape of the present invention, the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive composition mainly composed of an acrylic polymer having a glass transition temperature (Tg) of 0 ° C. or lower. It is used. As such an acrylic polymer, those having a glass transition temperature of −10 ° C. or lower (particularly −20 ° C. or lower) are suitable. When the glass transition temperature of the acrylic polymer exceeds 0 ° C., tackiness is lost at low temperatures, and workability is significantly deteriorated. In addition, the glass transition temperature of an acrylic polymer means the numerical value calculated | required using following formula (1).
W / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wn / Tgn (1)
[In Formula (1), W is the weight fraction of the total amount of monomer components, Tg is the glass transition temperature (K) of the acrylic polymer, Wn (n = 1, 2,..., N) is the monomer component n (n = 1, 2,..., N) weight fraction, Tgn (n = 1, 2,..., N) is a homopolymer of monomer component n (n = 1, 2,..., N) Represents the glass transition temperature (K). ]

  Therefore, an acrylic polymer having a glass transition temperature of 0 ° C. or less can be prepared by appropriately setting the type and ratio of the monomer component using the formula (1).

Such an acrylic polymer is a polymer in which one or more (meth) acrylic acid esters (acrylic acid ester, methacrylic acid ester) are used as a monomer main component (monomer main component), As the (meth) acrylic acid ester as the monomer main component, a (meth) acrylic acid alkyl ester is suitable. As (meth) acrylic acid alkyl ester, in particular, (meth) acrylic acid n-butyl, (meth) acrylic acid isobutyl, (meth) acrylic acid s-butyl, (meth) acrylic acid t-butyl, (meth) acrylic Pentyl acid, isoamyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, (meth) acrylic acid (Meth) such as 2-ethylhexyl, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate Acrylic acid C _4-12 alkyl esters are preferred.

  In addition, in the acrylic polymer, (meth) acrylic acid ester is used as a monomer main component, so the proportion of (meth) acrylic acid ester is 50% by weight or more based on the total amount of monomer components. It is important to be used in a proportion, preferably 70% by weight or more (more preferably 80% by weight or more). The upper limit of the ratio of (meth) acrylic acid ester is, of course, 100% by weight or less, preferably 97% by weight or less (more preferably 95% by weight or less).

  As a monomer component constituting such an acrylic polymer, if a (meth) acrylic acid ester is used as a main monomer component, another monomer component (copolymerizable monomer component) that can be copolymerized with the (meth) acrylic acid ester 1) or 2 or more types may be used. As such a copolymerizable monomer component, it can select suitably from well-known monomer components as another monomer component which can be copolymerized with (meth) acrylic acid ester.

  In the present invention, the copolymerizable monomer component includes a carboxyl group-containing monomer such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, and isocrotonic acid, or an acid anhydride thereof (maleic anhydride, icotane anhydride). Acid etc.) are particularly suitable. Such a carboxyl group-containing monomer or anhydride thereof is preferably used in a proportion of 1 to 10% by weight based on the total amount of monomer components. When the proportion of the carboxyl group-containing monomer or its anhydride is less than 1% by weight relative to the total amount of the monomer components, the adhesion to the adherend may be reduced, whereas when it exceeds 10% by weight, In some cases, the viscosity of the acrylic pressure-sensitive adhesive composition increases, and the coatability decreases.

  Examples of other copolymerizable monomer components include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 2-hydroxybutyl (meth) acrylate. In addition, hydroxyl group-containing monomers such as vinyl alcohol and allyl alcohol; (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane ( Amide monomers such as (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide; aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, (meta ) Acrylic acid t-butyl Amino group-containing monomers such as aminoethyl; epoxy group-containing monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate; cyano-containing monomers such as acrylonitrile and methacrylonitrile; N-vinyl-2-pyrrolidone, N -Methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N -Monomers having a nitrogen atom-containing ring such as vinyl caprolactam and N- (meth) acryloylmorpholine; Vinyl ester monomers such as vinyl acetate and vinyl propionate; Styrene, substituted styrene (α-methylstyrene, etc.), vinyl toluene Styrene monomers such as ethylene; olefin monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; vinyl chloride, vinylidene chloride; isocyanate group-containing monomers such as 2- (meth) acryloyloxyethyl isocyanate; methoxy (meth) acrylate Alkoxy group-containing monomers such as ethyl and ethoxyethyl (meth) acrylate; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether, 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol Di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, (poly) ethylene glycol di (me ) Acrylate, propylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol Multifunctional monomers such as tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin di (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, divinylbenzene, butyl di (meth) acrylate, hexyl di (meth) acrylate Etc.

When (meth) acrylic acid C _4-12 alkyl ester is used as the monomer main component, examples of copolymerizable monomer components include methyl (meth) acrylate, ethyl (meth) acrylate, ( meth) acrylic acid n- propyl, (meth) (meth) acrylic acid C _1-3 alkyl esters of isopropyl acrylate; (meth) acrylate, tridecyl (meth) acrylate and stearyl (meth) acrylic acid C _{13 -18} alkyl esters; (meth) acrylic acid cycloalkyl esters such as cyclohexyl (meth) acrylate; other (meth) acrylic acid esters such as (meth) acrylic aryl esters such as phenyl (meth) acrylate You can also.

  In the present invention, the amount of the copolymerizable monomer component used may be set so that the glass transition temperature of the resulting acrylic polymer is −20 ° C. or lower in order to develop good adhesion. desirable.

  The polymerization method for preparing the acrylic polymer is not particularly limited, and can be appropriately selected from known polymerization methods (solution polymerization method, emulsion polymerization method, UV polymerization method, bulk polymerization method, etc.). From the viewpoints of transparency, water resistance, cost, etc., a solution polymerization method is preferred.

  In the polymerization, a polymerization initiator can be used. Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2,4 -Dimethylvaleronitrile), 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2,4,4-trimethyl) Pentane), dimethyl 2,2'-azobis (2-methylpropionate) and other azo polymerization initiators; benzoyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxy Benzoate, dicumyl peroxide, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butyl) Okishi) an oil-soluble polymerization initiator such as peroxide polymerization initiators such as cyclododecane and the like. A polymerization initiator can be used 1 type or in combination of 2 or more types.

  The amount of the polymerization initiator used may be a normal amount, for example, 0.01 to 1 part by weight with respect to 100 parts by weight of all monomer components.

  When the acrylic polymer is polymerized by the solution polymerization method, the solvent for polymerization can be appropriately selected and used as long as it is a commonly used solvent, such as ethyl acetate, n-butyl acetate, etc. Esters of aromatic hydrocarbons such as toluene; aliphatic hydrocarbons such as n-hexane; alicyclic hydrocarbons such as cyclohexane; ketones such as methyl ethyl ketone and methyl isobutyl ketone; Two or more types can be used in combination.

  The weight average molecular weight of the acrylic polymer can be selected, for example, from a range of 300,000 to 2,000,000 (preferably 400,000 to 1,200,000, more preferably 400,000 to 800,000). When the weight average molecular weight of the acrylic polymer is less than 300,000, the necessary adhesive force and cohesive force as the adhesive may be reduced. On the other hand, when the acrylic polymer exceeds 2 million, the coating property is increased due to the increase in the viscosity of the adhesive. Since problems such as defects may occur, neither is desirable.

  The weight average molecular weight of the acrylic polymer was measured by gel permeation chromatograph (GPC) method to make the polymer 1 g / L 0.2 wt% tetrahydrofuran (THF) solution, and eluent THF in standard polystyrene conversion. Is required. The apparatus is “HLC8120GPC” (manufactured by TOSOH), the column is “TSKgelSuperHM-H / H4000 / H3000 / H2000”, the flow rate is “0.6 mL / min”, the detector is “RI”, and the column temperature is “40 ° C.”. Is.

  In the present invention, the acrylic pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer preferably further contains an acrylic oligomer having a weight average molecular weight of 3000 or more and less than 20000, and / or a tackifier resin. . Thus, when the acrylic pressure-sensitive adhesive composition contains an acrylic oligomer having a weight average molecular weight of 3000 or more and less than 20000, or a tackifying resin, the adhesiveness of the metal foil pressure-sensitive adhesive tape of the present invention is fixed. It becomes good.

  The blending ratio of the acrylic oligomer having a weight average molecular weight of 3000 or more and less than 20000 and / or the tackifier resin is, for example, acrylic polymer / (acrylic oligomer having a weight average molecular weight of 3000 or more and less than 20000, and / or Or tackifying resin) (solid content weight ratio) = 100/5 to 100/35 (preferably 100/15 to 100/30). When the blending ratio of the acrylic oligomer and / or tackifying resin having a weight average molecular weight of 3000 or more and less than 20000 is less than 5 parts by weight with respect to 100 parts by weight of the acrylic polymer, the weight average molecular weight is 3000 or more and 20000. The addition effect of less than acrylic oligomers and tackifying resins is low. On the other hand, if it exceeds 35 parts by weight, the adhesive properties of the acrylic polymer are greatly affected, which is not desirable.

(Acrylic oligomer)
The acrylic oligomer is not particularly limited as long as it is an acrylic oligomer having a weight average molecular weight of 3000 or more and less than 20000, but (meth) acrylic acid ester as a monomer main component (monomer main component) is a homopolymer glass. An acrylic oligomer having a (meth) acrylate having a transition temperature of 60 ° C. to 190 ° C. is preferred. Examples of the (meth) acrylate having such a homopolymer having a glass transition temperature of 60 ° C. to 190 ° C. include, for example, methacrylic acid C _1- such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, and isopropyl methacrylate. ₄ alkyl ester; isobornyl acrylate, cyclohexyl methacrylate, isobornyl methacrylate and the like. Moreover, styrene can also be used as a monomer component whose glass transition temperature of a homopolymer is 60 to 190 degreeC.

In such acrylic oligomers, (meth) acrylic acid esters such as methacrylic acid C _1-4 alkyl esters and non-aromatic ring-containing (meth) acrylic acid esters are used as monomer main components. The proportion of the (meth) acrylic acid ester as the main monomer component is important to be used in a proportion of 50% by weight or more, preferably 70% by weight or more, based on the total amount of the monomer components. (More preferably 80% by weight or more). The upper limit of the ratio of (meth) acrylic acid ester is, of course, 100% by weight or less, preferably 97% by weight or less (more preferably 95% by weight or less).

  In order to control the compatibility of the acrylic oligomer with the acrylic polymer, it is preferable that one or more functional group-containing monomer components are used as the monomer component. Examples of such functional group-containing monomer components include carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, and isocrotonic acid, or acid anhydrides thereof (maleic anhydride, anhydrous Tertiary amino group-containing monomers such as N, N-dimethylaminoethyl (meth) acrylate and N, N-diethylaminoethyl (meth) acrylate; (meth) acryloylmorpholine, N-vinyl-2-pyrrolidone Monomers having a nitrogen atom-containing ring such as (NVP); dialkyl acrylamides such as N, N-dimethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide; maleimides such as cyclohexylmaleimide and the like. In the acrylic oligomer, preferred functional group-containing monomer components include carboxyl group-containing monomers or acid anhydrides thereof, and tertiary amino group-containing monomers (more preferably acrylic acid, N, N-dimethylaminoethyl (meth) acrylate). It is.

  Other monomer components can also be used as the copolymerizable monomer component. Such other monomer component can be appropriately selected from the monomer components used in the acrylic polymer.

  The weight average molecular weight of the acrylic oligomer is not particularly limited as long as it is 3000 or more and less than 20000, but is preferably 3000 or more and less than 10,000. When the weight average molecular weight of the acrylic oligomer is less than 3000, the heat resistance is lowered, and when it is 20000 or more, the compatibility is lowered. In addition, the weight average molecular weight of an acrylic oligomer is calculated | required similarly to the weight average molecular weight of the acrylic polymer in the said acrylic adhesive composition.

  The polymerization method for preparing the acrylic oligomer is not particularly limited, and can be appropriately selected from known polymerization methods (solution polymerization method, emulsion polymerization method, UV polymerization method, bulk polymerization method, etc.). From the viewpoints of transparency, water resistance, cost and the like, the solution polymerization method is preferable as in the case of the acrylic polymer.

  As a polymerization initiator used at the time of superposition | polymerization, it can select suitably from well-known polymerization initiators, For example, what was illustrated as a polymerization initiator used for the bond of the said acrylic polymer polymerization, etc. are mentioned. . As a usage-amount of a polymerization initiator, a normal usage-amount may be sufficient, for example, it is 0.1-15 weight part with respect to 100 weight part of all the monomer components.

  In preparing the acrylic oligomer, a chain transfer agent may be used to control the weight average molecular weight to 3000 or more and less than 20000. The chain transfer agent can be appropriately selected from known chain transfer agents. For example, lauryl mercaptan, glycidyl mercaptan, 2-mercaptoethanol, mercaptoacetic acid, 2-ethylhexyl thioglycolate, 2,3-dimercapto- Examples thereof include 1-propanol and α-methylstyrene dimer. A chain transfer agent can be used 1 type or in combination of 2 or more types. As a usage-amount of a chain transfer agent, it is 0.01-15 weight part normally with respect to 100 weight part of all the monomer components.

(Tackifying resin)
It does not restrict | limit especially as tackifying resin, It can select suitably from well-known tackifying resin. Specifically, as the tackifying resin, for example, rosin-based tackifying resin (for example, unmodified rosin, modified rosin, rosin phenol-based resin, rosin ester-based resin, etc.), terpene-based tackifying resin (for example, terpene-based resin) Resin, terpene phenol resin, styrene modified terpene resin, aromatic modified terpene resin, hydrogenated terpene resin), hydrocarbon tackifier resin (for example, aliphatic hydrocarbon resin, aliphatic cyclic hydrocarbon resin) , Aromatic hydrocarbon resins (styrene resins, xylene resins, etc.), aliphatic / aromatic petroleum resins, aliphatic / alicyclic petroleum resins, hydrogenated hydrocarbon resins, coumarone resins, coumarone indenes Resins), phenolic tackifier resins (eg, alkylphenolic resins, xyleneformaldehyde resins, resols, Novolac, etc.), ketone-based tackifying resins, polyamide-based tackifying resins, epoxy-based tackifying resins, such as an elastomer-based tackifying resins. Tackifying resins can be used alone or in combination of two or more. As the tackifier resin, a rosin tackifier resin, a terpene tackifier resin, or a hydrocarbon tackifier resin (such as a styrene resin) can be suitably used.

  In this invention, the crosslinking agent may be mix | blended with the acrylic adhesive composition for forming an adhesive layer. As a crosslinking agent, it can select suitably from well-known crosslinking agents, for example, polyfunctional melamine compounds, such as methylated methylol melamine and butylated hexamethylol melamine; polyfunctionality, such as diglycidyl aniline and glycerin diglycidyl ether Epoxy compounds; polyfunctional isocyanate compounds such as tolylene diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate, diphenylmethane diisocyanate, trimethylolpropane tolylene diisocyanate, polyether polyisocyanate, polyester polyisocyanate, etc. . A crosslinking agent can be used 1 type or in combination of 2 or more types. As a usage-amount of a crosslinking agent, it is good to set it as the range of 0.01-20 weight part (preferably 0.1-10 weight part) normally with respect to 100 weight part of acrylic polymers.

  In addition to these components (acrylic polymer, acrylic oligomer, tackifier resin, cross-linking agent) in the acrylic pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer, for example, ultraviolet absorption Known agents, light stabilizers, release modifiers, plasticizers, softeners, fillers, colorants (pigments, dyes, etc.), anti-aging agents, surfactants, flame retardants, antistatic agents, antioxidants, etc. Additives and the like may be included.

  The method for forming the pressure-sensitive adhesive layer is not particularly limited. For example, a method of applying an acrylic pressure-sensitive adhesive composition on a predetermined surface of a metal foil as a substrate and drying or curing as necessary (application) Forming method) or an acrylic pressure-sensitive adhesive composition on a separator (release liner), and drying or curing as necessary to form a pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer is used as a substrate. A method (transfer forming method) of attaching and transferring on a predetermined surface of a metal foil may be used.

  Although the thickness in particular of an adhesive layer is not restrict | limited, For example, it can select from the range of 5-1000 micrometers (preferably 10-100 micrometers). The pressure-sensitive adhesive layer may have either a single layer or a multilayer.

[Metal foil]
In the metal foil pressure-sensitive adhesive tape of the present invention, the metal foil is used as a substrate. As the metal foil, a general metal foil such as a copper foil, a stainless steel foil, and an aluminum foil can be used, and an aluminum foil advantageous in terms of cost and workability can be suitably used.

  As thickness of metal foil, it can select suitably from the range of 10-300 micrometers (preferably 20-100 micrometers, More preferably, 30-80 micrometers).

  The metal foil may have a single layer form or may have a laminated form.

[Metal foil adhesive tape]
The metal foil pressure-sensitive adhesive tape of the present invention has a configuration in which a pressure-sensitive adhesive layer is formed on one surface of a metal foil and a back treatment layer is formed on the other surface. Specifically, the metal foil pressure-sensitive adhesive tape has a form in which the pressure-sensitive adhesive layer formed on one surface of the metal foil is wound into a roll shape in contact with the back treatment layer formed on the other surface. Have. The metal foil, the pressure-sensitive adhesive layer, and the back treatment layer are as described above.

  Therefore, the metal foil pressure-sensitive adhesive tape is formed into a roll shape in such a manner that the pressure-sensitive adhesive layer and the back surface treatment layer are in contact with each other after the pressure-sensitive adhesive layer is formed on one surface of the metal foil and the back surface treatment layer is formed on the other surface. It can be produced by winding. In addition, when winding a metal foil adhesive tape in roll shape, a winding core can be used. The core is not particularly limited and can be appropriately selected from known cores (plastic core, paper core, metal core, etc.).

  Since the metal foil pressure-sensitive adhesive tape of the present invention has the above-described configuration, when it is rewound at the time of use, it can be easily rewound with a light force, and workability at the time of rewinding (rewinding workability) is improved. Are better. In addition, since the back treatment layer contains an acrylic polymer, the adhesion to the polyurethane component (urethane adhesion) is good, and the adhesion with the polyurethane component can be effectively maintained over a long period of time. it can. For this reason, the metal foil pressure-sensitive adhesive tape of the present invention can be suitably used for applications in which the metal foil pressure-sensitive adhesive tape is covered with a polyurethane component after being attached to an adherend. Therefore, the metal foil pressure-sensitive adhesive tape of the present invention can be suitably used as a metal foil pressure-sensitive adhesive tape used when fixing a member such as a heat radiating tube in a refrigerator.

[refrigerator]
The refrigerator of the present invention has a configuration in which the heat radiating tube has the metal foil pressure-sensitive adhesive tape (that is, a pressure-sensitive adhesive layer is formed on one surface of the metal foil and a back treatment layer is formed on the other surface. And the pressure-sensitive adhesive layer is formed of an acrylic pressure-sensitive adhesive composition mainly composed of an acrylic polymer having a glass transition temperature of 0 ° C. or lower, and the back treatment layer is mainly composed of a silicone component having a diorganosiloxane skeleton. It is the refrigerator fixed by the metal foil adhesive tape which has the structure formed with the back surface processing agent composition containing the silicone type release agent and acrylic polymer which are a component. More specifically, in the refrigerator of the present invention, the space including the portion where the heat radiating tube is fixed by the metal foil adhesive tape and the heat radiating tube is fixed is a polyurethane component (for example, a two-component curing type hard polyurethane). It is the refrigerator which has the structure buried by.

  Thus, the refrigerator of the present invention is characterized in that the metal foil pressure-sensitive adhesive tape is used, and other configurations may be any configuration.

  The refrigerator of the present invention is manufactured by filling a space including a portion where the heat radiating tube is fixed with a polyurethane component (for example, a two-component curable hard polyurethane) after fixing the heat radiating tube with a metal foil adhesive tape. be able to.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

(Preparation Example 1 of Acrylic Polymer for Back Treatment Layer)
As monomer components, butyl acrylate: 25 parts by weight, methyl methacrylate: 65 parts by weight, 2-hydroxyethyl acrylate: 10 parts by weight, benzoyl peroxide as a polymerization initiator: 0.2 parts by weight, and acetic acid as a polymerization solvent 120 parts by weight of ethyl was put into a separable flask and stirred at room temperature (23 ° C.) for 1 hour while introducing nitrogen gas. In this way, after removing oxygen in the polymerization system, the temperature was raised to 70 ° C. and reacted for 8 hours. After completion of the reaction, ethyl acetate was added to obtain an acrylic polymer solution having a solid content concentration of 25% by weight (sometimes referred to as “acrylic polymer solution A”).

(Preparation Example 2 of Acrylic Polymer for Back Treatment Layer)
The solid content was the same as in Preparation Example 1 of the acrylic polymer for the back treatment layer, except that the monomer components were butyl acrylate: 25 parts by weight, methyl methacrylate: 65 parts by weight, and acrylic acid: 10 parts by weight. An acrylic polymer solution having a concentration of 25% by weight (sometimes referred to as “acrylic polymer solution B”) was obtained.

(Preparation Example 3 of Acrylic Polymer for Back Treatment Layer)
Except that the monomer components were butyl acrylate: 25 parts by weight, methyl methacrylate: 65 parts by weight, and N, N-diethylacrylamide: 10 parts by weight, the same procedure as in Preparation Example 1 for the backside treatment layer acrylic polymer was performed. Thus, an acrylic polymer solution having a solid content concentration of 25% by weight (sometimes referred to as “acrylic polymer solution C”) was obtained.

(Preparation Example 4 of Acrylic Polymer for Back Treatment Layer)
Acrylic polymer having a solid content concentration of 25% by weight in the same manner as in Preparation Example 1 of the acrylic polymer for the back treatment layer, except that the monomer components were butyl acrylate: 25 parts by weight and methyl methacrylate: 65 parts by weight. A polymer solution (sometimes referred to as “acrylic polymer solution D”) was obtained.

(Preparation Example 1 of acrylic polymer for pressure-sensitive adhesive layer)
As monomer components, butyl acrylate: 65 parts by weight, 2-ethylhexyl acrylate: 32 parts by weight, acrylic acid: 3 parts by weight, 2-hydroxyethyl acrylate: 0.2 parts by weight, 2,2 ′ as a polymerization initiator -Azobisisobutyronitrile: 0.1 part by weight and 100 parts by weight of toluene as a polymerization solvent were put into a separable flask and stirred at room temperature (23 ° C) for 1 hour while introducing nitrogen gas. After removing oxygen in the polymerization system in this way, the temperature was raised to 60 ° C. and reacted for 3 hours, and further heated to 70 ° C. and reacted for 2 hours, diluted with toluene to be diluted with solids. An acrylic polymer solution having a concentration of 30% by weight (sometimes referred to as “acrylic polymer solution E”) was obtained.

(Preparation Example 1 of acrylic oligomer for pressure-sensitive adhesive layer)
As monomer components, cyclohexyl methacrylate (Tg of homopolymer: 66 ° C.): 96 parts by weight, acrylic acid: 4 parts by weight, 2-mercaptoethanol: 3 parts by weight as a chain transfer agent, and 2,2′- as a polymerization initiator Azobisisobutyronitrile: 0.2 parts by weight and toluene: 120 parts by weight as a polymerization solvent were put into a separable flask and stirred at room temperature (23 ° C.) for 1 hour while introducing nitrogen gas. After removing oxygen in the polymerization system in this way, the temperature was raised to 70 ° C. and reacted for 3 hours, and further reacted at 75 ° C. for 2 hours to obtain an acrylic oligomer solution having a solid content concentration of 50% by weight (“ May be referred to as “acrylic oligomer solution A”).

  The weight average molecular weight of the acrylic oligomer in the acrylic oligomer solution A was 4000. The weight average molecular weight of the acrylic oligomer was measured under the same measurement conditions as the weight average molecular weight of the acrylic polymer in the acrylic pressure-sensitive adhesive composition.

(Example 1)
The following silicone resin composition b was used as the silicone release agent.
Silicone-based resin composition b: side chain methoxy-modified polydimethylsiloxane and terminal hydroxyl group-modified polydimethylsiloxane in a ratio of side chain methoxy-modified polydimethylsiloxane / terminal hydroxyl group-modified polydimethylsiloxane = 1/9 (weight ratio). Containing silicone-based resin composition (viscosity: 0.13 Pa · s (25 ° C.), solid content concentration: 50% by weight)

  Silicone resin composition b: 100 parts by weight (solid content), tin catalyst (trade name “PS-3” manufactured by Shin-Etsu Chemical Co., Ltd.): 5 parts by weight, acrylic polymer solution A: 50 parts by weight (solid content) ), And toluene to prepare a back surface treatment composition having a solid content concentration of 2.0% by weight. This back surface treatment composition was added to an aluminum foil (thickness: 50 μm) with a Mayer bar # 10. It apply | coated to one side and it was made to dry at 150 degreeC for 1 minute, and the back process layer was formed (thickness of a back process layer: 0.3 micrometer).

  Also, an acrylic pressure-sensitive adhesive composition is obtained by adding 2.0 parts by weight of an isocyanate-based crosslinking agent (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) to 100 parts by weight (solid content) of the acrylic polymer solution E. And the thickness of the acrylic pressure-sensitive adhesive composition after drying is about 50 μm on the untreated surface (the surface on which the back surface treatment layer is not formed) of the aluminum foil subjected to the back surface treatment. After casting and coating at 130 ° C. for 2 minutes to form an adhesive layer, the adhesive surface (adhesive layer surface) is wound so that the back treatment layer surface (rear treatment surface) is in close contact And aged at 50 ° C. for 24 hours to prepare a metal foil adhesive tape.

(Example 2)
As the silicone release agent, the following silicone resin composition a was used together with the same silicone resin composition b as in Example 1.
Silicone resin composition a: silicone resin composition obtained by adding ethyl cellulose to side chain methoxy-modified polydimethylsiloxane (ethyl cellulose content: 75% by weight, viscosity: 10 Pa · s (25 ° C.), solid content concentration: 20 weight%)

  Silicone resin composition b: instead of 100 parts by weight (solid content), silicone resin composition a: 60 parts by weight (solid content) and silicone resin composition b: 40 parts by weight (solid content) Mixture: A backside treatment composition having a solid content concentration of 2.0% by weight was prepared in the same manner as in Example 1 except that 100 parts by weight (solid content) was used. A metal foil pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that this back surface treating agent composition was used.

  That is, a silicone-based resin composition a: 60 parts by weight (solid content) and a silicone-based resin composition b: 40 parts by weight (solid content): 100 parts by weight (solid content) Name “PS-3” manufactured by Shin-Etsu Chemical Co., Ltd.): 5 parts by weight, acrylic polymer solution A: 50 parts by weight (solid content), and toluene, and a backside treatment composition having a solid content concentration of 2.0% by weight The back treatment composition was applied to one side of an aluminum foil (thickness: 50 μm) with a Mayer bar # 10 and dried at 150 ° C. for 1 minute to form a back treatment layer ( The thickness of the back treatment layer: 0.3 μm).

  Also, an acrylic pressure-sensitive adhesive composition is obtained by adding 2.0 parts by weight of an isocyanate-based crosslinking agent (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) to 100 parts by weight (solid content) of the acrylic polymer solution E. And the thickness of the acrylic pressure-sensitive adhesive composition after drying is about 50 μm on the untreated surface (the surface on which the back surface treatment layer is not formed) of the aluminum foil subjected to the back surface treatment. After casting and coating at 130 ° C. for 2 minutes to form an adhesive layer, the adhesive surface (adhesive layer surface) is wound so that the back treatment layer surface (rear treatment surface) is in close contact And aged at 50 ° C. for 24 hours to prepare a metal foil adhesive tape.

(Example 3)
A backside treatment composition having a solid content concentration of 1.0% by weight was prepared in the same manner as in Example 2 except that the solid content concentration of the backside treatment composition was changed to 1.0% by weight with toluene. did. A metal foil pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that this backside treatment composition was used and the thickness of the backside treatment layer was 0.15 μm.

Example 4
A backside treatment composition having a solid content concentration of 4.0% by weight was prepared in the same manner as in Example 2 except that the solid content concentration of the backside treatment composition was changed to 4.0% by weight with toluene. did. A metal foil pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that this backside treatment composition was used and the thickness of the backside treatment layer was 0.6 μm.

(Example 5)
The solid content concentration was 2.0 wt.% In the same manner as in Example 2 except that the amount of the acrylic polymer solution A was 25 wt. Parts (solid) instead of 50 wt. % Backside treatment composition was prepared. A metal foil pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that this back surface treating agent composition was used.

(Example 6)
The solid content concentration was 2.0 wt.% In the same manner as in Example 2 except that the amount of the acrylic polymer solution A was changed to 100 wt. Parts (solid content) instead of 50 parts by weight (solid content). % Backside treatment composition was prepared. A metal foil pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that this back surface treating agent composition was used.

(Example 7)
Acrylic polymer solution E: 100 parts by weight (solid content), isocyanate cross-linking agent (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.): 2.0 parts by weight, acrylic oligomer solution A: 25 parts by weight (solid) And an acrylic pressure-sensitive adhesive composition was prepared. A metal foil pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that this acrylic pressure-sensitive adhesive composition was used.

(Example 8)
Back treatment agent having a solid content concentration of 2.0% by weight in the same manner as in Example 2 except that 50 parts by weight (solid content) of the acrylic polymer solution B was used instead of the acrylic polymer solution A. A composition was prepared. A metal foil pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that this back surface treating agent composition was used.

Example 9
Back treatment agent having a solid content concentration of 2.0% by weight in the same manner as in Example 2 except that 50 parts by weight (solid content) of the acrylic polymer solution C was used instead of the acrylic polymer solution A. A composition was prepared. A metal foil pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that this back surface treating agent composition was used.

(Example 10)
Back treatment agent having a solid content concentration of 2.0% by weight in the same manner as in Example 2 except that 50 parts by weight (solid content) of the acrylic polymer solution D was used instead of the acrylic polymer solution A. A composition was prepared. A metal foil pressure-sensitive adhesive tape was produced in the same manner as in Example 2 except that this back surface treating agent composition was used.

(Comparative Example 1)
The same silicone resin composition b as in Example 1: 100 parts by weight (solid content), tin catalyst (trade name “PS-3” manufactured by Shin-Etsu Chemical Co., Ltd.): 5 parts by weight, and toluene were added to form a solid. A backside treatment composition having a partial concentration of 2.0% by weight was prepared. This back surface treatment agent composition was applied to one side of an aluminum foil (thickness: 50 μm) with a Mayer bar # 16 and dried at 150 ° C. for 1 minute to form a back surface treatment layer (the thickness of the back surface treatment layer). (0.3 μm).

  Also, an acrylic pressure-sensitive adhesive composition is obtained by adding 2.0 parts by weight of an isocyanate-based crosslinking agent (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) to 100 parts by weight (solid content) of the acrylic polymer solution E. And the thickness of the acrylic pressure-sensitive adhesive composition after drying is about 50 μm on the untreated surface (the surface on which the back surface treatment layer is not formed) of the aluminum foil subjected to the back surface treatment. After casting and coating at 130 ° C. for 2 minutes to form an adhesive layer, the adhesive surface (adhesive layer surface) is wound so that the back treatment layer surface (rear treatment surface) is in close contact And aged at 50 ° C. for 24 hours to prepare a metal foil adhesive tape.

(Comparative Example 2)
Acrylic polymer solution A: To 100 parts by weight (solid content), toluene was added to prepare a back surface treatment composition having a solid content concentration of 2.0% by weight. Then, it was applied to one side of an aluminum foil (thickness: 50 μm) and dried at 150 ° C. for 1 minute to form a back treatment layer (thickness of the back treatment layer: 0.3 μm).

  Also, an acrylic pressure-sensitive adhesive composition is obtained by adding 2.0 parts by weight of an isocyanate-based crosslinking agent (trade name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) to 100 parts by weight (solid content) of the acrylic polymer solution E. And the thickness of the acrylic pressure-sensitive adhesive composition after drying is about 50 μm on the untreated surface (the surface on which the back surface treatment layer is not formed) of the aluminum foil subjected to the back surface treatment. After casting and coating at 130 ° C. for 2 minutes to form an adhesive layer, the adhesive surface (adhesive layer surface) is wound so that the back treatment layer surface (rear treatment surface) is in close contact And aged at 50 ° C. for 24 hours to prepare a metal foil adhesive tape.

(Evaluation)
About the metal foil adhesive tape obtained by Examples 1-10 and Comparative Examples 1-2, the back surface adhesiveness and urethane adhesiveness were evaluated with the following evaluation method. The evaluation results are shown in Table 1 or Table 2.

  In addition, the case where the self-back surface adhesiveness is good and the urethane adhesiveness is good is defined as “◯ (good)”, and the case where at least one of the self-back surface adhesive property and the urethane adhesive property is defective is determined as “ A comprehensive evaluation was also carried out as “× (defect)”.

(Self-back adhesion evaluation method)
A metal foil adhesive tape cut to a width of 25 mm is reciprocated once with a 5 kg roller on the back surface of the tape, left at room temperature (23 ° C.) for 24 hours, and then pulled in the direction of 90 ° at a speed of 300 mm / min. It peeled off and the self-back surface adhesive force was measured. Then, the case where the self-back surface adhesive strength was less than 10 N / 25 mm was evaluated as “◯ (good)”, and the case where the self-back surface adhesive strength was 10 N / 25 mm or more was evaluated as “× (defective)”, and the self-back surface adhesiveness was evaluated.

(Urethane adhesion evaluation method)
A two-component urethane foam (Quicklight II (two-component mixed type) manufactured by INOAC Corporation) was applied to the back surface (surface on the back treatment layer side) of the metal foil adhesive tape cut to a width of 38 mm and foamed. After 5 hours in an environment of 23 ° C. and 50% RH, the metal foil pressure-sensitive adhesive tape is peeled off from the urethane foam at a speed of 300 mm / min in the direction of 90 °, and the peeling force (that is, urethane) Adhesive strength to components) was measured. And the case where the adhesive force with respect to a urethane component is 0.5 N / 38 mm or more was evaluated as “◯ (good)”, and the case where it was less than 0.5 N / 38 mm was evaluated as “x (defect)”, and the urethane adhesion was evaluated. .

  As is clear from Tables 1 and 2, it was confirmed that the metal foil pressure-sensitive adhesive tapes according to the examples had a good balance of self-back surface adhesiveness and urethane adhesiveness and were excellent. That is, the metal foil pressure-sensitive adhesive tape according to the example has good adhesion to the polyurethane component on the back surface and excellent workability when rewinding.

  In Tables 1 and 2, the unit of the amount of each component (silicone resin composition a to silicone resin composition b, acrylic polymer solution A to acrylic polymer solution D, etc.) in the backside treatment composition is Part by weight (solid content).

Claims (5)

  A metal foil pressure-sensitive adhesive tape having a configuration in which a pressure-sensitive adhesive layer is formed on one surface of a metal foil and a back treatment layer is formed on the other surface, and the pressure-sensitive adhesive layer has a glass transition temperature of 0 ° C. or lower. A silicone release agent that is formed of an acrylic pressure-sensitive adhesive composition containing an acrylic polymer as a main component, and the back treatment layer contains a silicone component of a diorganosiloxane skeleton as a main component, and an acrylic polymer. A metal foil pressure-sensitive adhesive tape, characterized in that it is formed of a back surface treatment agent composition.   The metal foil according to claim 1, wherein the acrylic pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer further comprises an acrylic oligomer having a weight average molecular weight of 3000 or more and less than 20000 and / or a tackifying resin. Adhesive tape.   The metal foil pressure-sensitive adhesive tape according to claim 1 or 2, wherein the silicone release agent in the back treatment composition for forming the back treatment layer is a condensation reaction type silicone release agent.   The metal foil pressure-sensitive adhesive tape according to any one of claims 1 to 3, wherein the acrylic polymer in the back treatment composition for forming the back treatment layer is an acrylic polymer containing a functional group.   It is a refrigerator in which a radiator pipe is fixed by a metal foil adhesive tape, and the metal foil adhesive tape according to any one of claims 1 to 4 is used as the metal foil adhesive tape. Refrigerator.