TW202405117A - adhesive sheet - Google Patents

Abstract

The present invention provides an adhesive sheet which has excellent electrical conductivity and excellent reworkability, and is increased in the adhesive force with time, while having a small amount of outgas. An adhesive sheet 1 according to the present invention comprises a metal base material 2 and an adhesive layer 3 that is arranged on at least one surface of the metal base material 2. The adhesive layer 3 contains, relative to 100 parts by mass of a polymer (A) that has a glass transition temperature of less than 0 DEG C, 0.1 part by mass to 20 parts by mass of a polymer (B) that contains, as monomer units, a monomer (B1) having a polyorganosiloxane skeleton and a monomer (B2) having a homopolymer glass transition temperature of 40 DEG C or more, wherein the monomer (B1) has a functional group equivalent (arithmetic average) of not less 1,000 g/mol but less than 15,000 g/mol and a weight average molecular weight of not less than 10,000 but less than 100,000, and 0.4 part by mass or more of a phenolic antioxidant.

Description

adhesive sheet

The present invention relates to an adhesive sheet.

Lithium batteries, which are rapidly developing as power sources for electronic equipment represented by mobile machines, are also being used in EV vehicles (Electric Vehicles). In addition to the load capacity, the top priority for EV vehicles is also the urgent need to solve problems caused by the electrolyte contained in the battery, such as deformation (expansion) or fire during use. Therefore, in recent years, the popularization of all-solid-state batteries has been highly anticipated, and adhesive sheets (adhesive tapes) are used for fixing circuit parts of such batteries. The adhesive sheet is required to have excellent electrical conductivity.

In addition, if the adhesive sheet has a high adhesive force from the initial stage of adhesion, it will be difficult to reattach it. Therefore, the initial adhesive force is weak but the adherend can be firmly fixed. It is necessary to seek an adhesive force that changes over time. rise, and can obtain adhesive sheets with higher adhesion.

Patent Document 1 discloses an adhesive composition that can form an adhesive layer that has a weak initial adhesive force, can be easily peeled off from an adherend, has excellent secondary processability, and has an adhesive force that increases with time. Prior technical literature patent documents

Patent Document 1: Japanese Patent Application Publication No. 2014-224227

[Problem to be solved by the invention]

From the viewpoint of environmental protection or the prevention of ignition caused by ignition, adhesive sheets for fixing circuit components of all-solid-state batteries are required to have a small amount of outgassing.

The present invention was conceived in view of this situation, and its purpose is to provide an adhesive sheet that is excellent in conductivity and secondary processability, has an adhesive force that increases with time, and has a small amount of outgassing. [Technical means to solve problems]

The inventors of the present invention conducted intensive research to achieve the above object, and found that an adhesive sheet having a metal base material and a specific adhesive layer provided on at least one side of the adhesive sheet has excellent electrical conductivity and secondary processability, and the adhesive force increases with time. And the amount of gas released is less. The present invention was completed based on these findings.

That is, the present invention provides an adhesive sheet including a metal base material and an adhesive layer provided on at least one side of the metal base material, and The above-mentioned adhesive layer contains 0.1 to 20 parts by mass of polymer (B) and more than 0.4 parts by mass of phenolic antioxidant relative to 100 parts by mass of polymer (A) whose glass transition temperature is less than 0°C. The polymer (B) ) contains a monomer (B1) with a polyorganosiloxane skeleton and a monomer (B2) with a homopolymer glass transition temperature of 40°C or above as monomer units, and the functional group equivalent of the monomer (B1) (arithmetic average) is 1000 g/mol or more and less than 15000 g/mol, and the weight average molecular weight of the polymer (B) is 10000 or more but less than 100000.

The phenolic antioxidant preferably contains a compound having two or more phenolic skeletons.

The total gas release amount of the above-mentioned adhesive sheet is preferably less than 15500 ppm.

The above-mentioned adhesive sheet is preferably used for attaching battery components.

The above-mentioned adhesive sheet is preferably used for attaching all-solid-state battery components.

Furthermore, the present invention provides an electrode for an all-solid-state battery, which includes an insulating substrate, the adhesive sheet in which the adhesive layer is bonded to the insulating substrate, and the activity of a metal base material adhered to the adhesive sheet. material. [Effects of the invention]

The adhesive sheet of the present invention has excellent electrical conductivity and secondary processability, the adhesive force increases with time, and the amount of gas release is small. Therefore, the above-mentioned adhesive sheet is suitable for fixing circuit parts of all-solid-state batteries. In addition, the amount of outgassing generated at this time is small, so it is less likely to cause fire due to ignition.

＜Adhesive sheet＞ The adhesive sheet of the present invention at least includes a metal base material and an adhesive layer provided on at least one side of the metal base material. The adhesive sheet of the present invention may be a double-sided adhesive sheet in which both sides become the surface of the adhesive layer, or may be a single-sided adhesive sheet in which only one side becomes the surface of the adhesive layer.

FIG. 1 is a schematic cross-sectional view showing one embodiment of the adhesive sheet of the present invention. As shown in FIG. 1 , the adhesive sheet 1 is a single-sided adhesive sheet including a metal base material 2 and an adhesive layer 3 provided on one side of the metal base material 2 .

[Metal base material] The above-mentioned metal substrate is preferably a metal foil extending in the surface direction. The above-mentioned metal substrate may be a single layer or multiple layers. In the case of multiple layers, the constituent metal or thickness of each layer may be the same or different.

Examples of the metal constituting the metal base material include copper, aluminum, gold, nickel, titanium, molybdenum, niobium, tantalum, zirconium, alloys, and the like. Examples of the alloy include stainless steel, nickel-iron alloy, nickel-chromium alloy, and the like. As the above-mentioned metal, copper is preferred from the viewpoint of obtaining excellent electrical conductivity. That is, the metal base material is preferably copper foil.

The formation method of the above-mentioned metal substrate is not particularly limited. For example, electrolysis, evaporation (such as vacuum evaporation), sputtering, CVD (chemical vapor deposition, chemical vapor deposition) method, metal-organic (MO), Plating, rolling processing, etc.

The thickness of the metal substrate is, for example, 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. The thickness is, for example, 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, further preferably 80 μm or less, particularly preferably 50 μm or less.

[Adhesive layer] The above-mentioned adhesive layer contains at least: polymer (A), polymer (B), and phenolic antioxidant. By using this adhesive layer, the adhesive sheet of the present invention can be made to have low initial adhesive force to the adherend and excellent secondary processability, and the adhesive force increases with time, and the adhesiveness to the adherend is improved. Excellent adhesive sheet.

The above-mentioned adhesive layer contains 0.1 to 20 parts by mass of polymer (B) and 0.4 or more parts by mass of phenolic antioxidant based on 100 parts by mass of polymer (A). Furthermore, in this specification, the above-mentioned adhesive layer may be referred to as "the adhesive layer of the present invention".

The adhesive sheet of the present invention can be a double-sided adhesive sheet or a single-sided adhesive sheet. When the adhesive sheet of the present invention has multiple adhesive layers, at least one adhesive layer is the adhesive layer of the present invention, and preferably all the adhesive layers are the adhesive layers of the present invention. In addition, the plurality of adhesive layers may be the same, or may be adhesive layers with different compositions, thicknesses, physical properties, etc.

(Polymer(A)) Polymer (A) is a polymer whose glass transition temperature is less than 0°C. By including the polymer (A) in the adhesive layer, sufficient adhesion to the adherend can still be exerted over time.

Examples of the polymer (A) include acrylic polymers, rubber polymers, silicone polymers, polyurethane polymers, polyester polymers and the like that are commonly used as adhesives. polymer. Especially when the polymer (B) is a (meth)acrylic polymer, an acrylic polymer that is easily compatible with the (meth)acrylic polymer and has high transparency is preferred. Only one type of polymer (A) may be used, or two or more types may be used.

The glass transition temperature (Tg) of the polymer (A) is less than 0°C, preferably less than -10°C, more preferably less than -30°C. Moreover, it is preferable that the said glass transition temperature is -80 degreeC or more. If the Tg of the polymer (A) is 0° C. or higher, the polymer may not flow easily and the adhesive force may not easily increase with time.

The glass transition temperature is a nominal value described in literature, catalogs, etc., or a value calculated based on the following formula (X) (Fox formula). 1/Tg＝W ₁ /Tg ₁ +W ₂ /Tg ₂ +…+W _n /Tg _n (X) [In formula (X), Tg represents the glass transition temperature (unit: K) of polymer (A), Tg _i (i=1, 2,...n) represents the glass transition temperature (unit: K) of monomer i when it forms a homopolymer, Wi ( _i =1, 2,...n) represents monomer i among all monomers Mass fraction in components] The above formula (X) is a calculation formula when the polymer (A) is composed of n types of monomer components: monomer 1, monomer 2, ..., and monomer n.

Furthermore, the "glass transition temperature (Tg) when forming a homopolymer" in this specification (sometimes referred to as "Tg of the homopolymer") means "the glass transition temperature (Tg) of the homopolymer of the monomer. )", specifically, the numerical values in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc, 1987) can be cited. In addition, the Tg of the homopolymer of the monomers not described in the above-mentioned documents, except for the monomers having a polyorganosiloxane skeleton, refers to a value that can be obtained by the following measurement method (refer to Japanese Patent Application Laid-Open). Gazette No. 2007-51271). That is, 100 parts by mass of the monomer, 0.2 parts by mass of 2,2'-azobisisobutyronitrile, and 200 parts by mass of ethyl acetate as the polymerization solvent were put into a reactor equipped with a thermometer, a stirrer, a nitrogen introduction pipe, and a reflux condenser. mass part, and stirred for 1 hour while introducing nitrogen gas. After removing the oxygen in the polymerization system in this way, the temperature was raised to 63°C and the reaction was carried out for 10 hours. Next, it was cooled to room temperature to obtain a homopolymer solution with a solid content concentration of 33% by mass. Next, the homopolymer solution was cast-coated on a release liner and dried to prepare a sample (sheet-shaped homopolymer) with a thickness of approximately 2 mm. Then, the sample was punched into a disc shape with a diameter of 7.9 mm, clamped with parallel plates, and a viscoelasticity testing machine (trade name "ARES", manufactured by Rheometrics Co., Ltd.) was used to apply shear at a frequency of 1 Hz on one side. The strained side was measured in shear mode at a temperature range of -70 to 150°C and a heating rate of 5°C/min. The peak temperature of tan δ was set as the Tg of the homopolymer.

The weight average molecular weight (Mw) of the polymer (A) is preferably 5×10 ⁴ or more, more preferably 10×10 ⁴ or more, further preferably 20×10 ⁴ or more, particularly preferably 30×10 ⁴ or more. If the above-mentioned Mw is 5×10 ⁴ or more, an adhesive exhibiting good cohesiveness can be easily obtained. Moreover, the above-mentioned Mw is preferably 500×10 ⁴ or less. If the above-mentioned Mw is 500×10 ⁴ or less, it is easy to form an adhesive showing moderate fluidity (movement of the polymer chain), so it is suitable for achieving low initial adhesion and high adhesion after heating. The adhesive sheet.

In addition, in this specification, Mw of polymer (A) and polymer (B) can be calculated|required by polystyrene conversion by gel permeation chromatography (GPC). More specifically, Mw can be measured according to the methods and conditions described in the following examples.

The above-mentioned acrylic polymer is a polymer containing an acrylic monomer (a monomer having a (meth)acrylyl group in the molecule) as a monomer component constituting the polymer. That is, the acrylic polymer contains a structural unit derived from an acrylic monomer. The above-mentioned acrylic polymer may contain only one kind of acrylic monomer as a monomer component, or may contain two or more acrylic monomers as monomer components. Furthermore, in this specification, "(meth)acrylic acid" means "acrylic acid" and/or "methacrylic acid" (either or both of "acrylic acid" and "methacrylic acid"), and the same applies to others. .

The acrylic polymer is preferably a polymer containing the largest amount of structural units derived from (meth)acrylate in terms of mass ratio. Examples of the (meth)acrylate include hydrocarbon group-containing (meth)acrylate. Examples of the hydrocarbon group-containing (meth)acrylate include (meth)acrylic acid alkyl esters having a linear or branched aliphatic hydrocarbon group, (meth)acrylic acid cycloalkyl esters, and the like having an alicyclic ring. (meth)acrylate having an aromatic hydrocarbon group, such as (meth)acrylate having a hydrocarbon group, aryl (meth)acrylate, etc. Only one type of the above-mentioned hydrocarbon group-containing (meth)acrylate may be used, or two or more types may be used.

Examples of the alkyl (meth)acrylate include: (methyl)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, (meth)acrylate Butyl methacrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, third butyl (meth)acrylate, amyl (meth)acrylate, iso(meth)acrylate Pentyl ester, (meth)hexyl acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, (meth)acrylate Nonyl acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate Alkyl ester (lauryl (meth)acrylate), tridecyl (meth)acrylate, myristyl (meth)acrylate, pentadecyl (meth)acrylate, (meth) Cetyl acrylate, heptadecyl (meth)acrylate, stearyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate wait.

The above-mentioned alkyl (meth)acrylate is preferably one having a linear or branched aliphatic hydrocarbon group having a carbon number of 1 to 20 (preferably 4 to 12, more preferably 6 to 10). Alkyl (meth)acrylates. If the carbon number is within the above range, the glass transition temperature of the acrylic polymer can be easily adjusted, and the adhesiveness can be made more suitable.

As the above-mentioned alkyl (meth)acrylate, it is preferable to use at least an alkyl (meth)acrylate having an alkyl group having a carbon number of 1 to 18, and more preferably an alkyl (meth)acrylate having an alkyl group having a carbon number of 1 to 14. Alkyl acrylate with an alkyl group of 4 to 12, more preferably 6 to 10), particularly preferably n-butyl acrylate (BA) and/or 2-ethylhexyl acrylate (2EHA).

Moreover, examples of the (meth)acrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms include: methyl acrylate, methyl methacrylate (MMA), n-butyl methacrylate (BMA), 2-ethylhexyl methacrylate (2EHMA), isostearyl acrylate (ISTA), etc.

Examples of the (meth)acrylate having an alicyclic hydrocarbon group include: (meth)cyclopentyl acrylate, (meth)cyclohexyl acrylate, (meth)cycloheptyl acrylate, (meth)acrylate ) (Meth)acrylates with a monocyclic aliphatic hydrocarbon ring such as cyclooctyl acrylate; (meth)acrylates with a bicyclic aliphatic hydrocarbon ring such as isopropyl (meth)acrylate; (meth)acrylates )Dicyclopentyl acrylate, Dicyclopentyloxyethyl (meth)acrylate, Tricyclopentyl (meth)acrylate, 1-Adamantyl (meth)acrylate, 2-Methyl (meth)acrylate -2-Adamantyl ester, (meth)acrylic acid 2-ethyl-2-adamantyl ester and other (meth)acrylates having three or more aliphatic hydrocarbon rings.

Examples of the (meth)acrylate having an aromatic hydrocarbon group include phenyl (meth)acrylate, benzyl (meth)acrylate, and the like.

In order to appropriately express the basic characteristics such as adhesiveness generated by the above-mentioned hydrocarbon group-containing (meth)acrylate in the above-mentioned adhesive layer, the above-mentioned hydrocarbon group-containing (meth)acrylic acid ester in all monomer components constituting the above-mentioned acrylic polymer The ratio of acrylic acid ester is preferably 50 mass% or more, more preferably 60 mass% or more, and still more preferably 70 mass% or more relative to the total amount (100 mass%) of all the above-mentioned monomer components. In addition, the above ratio may be 99.9 mass% or less, 98 mass% or less, 95 mass% or less, or 90 mass% from the viewpoint that it can be copolymerized with other monomer components to obtain the effects of the other monomer components. % or less, 80 mass% or less.

The acrylic polymer may contain structural units derived from other monomer components copolymerizable with the hydrocarbon group-containing (meth)acrylate in order to achieve modifications such as improvement of cohesive force or introduction of cross-linking points. Examples of the other monomer components include carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, and phosphate group-containing monomers. , monomers containing nitrogen atoms, monomers containing polar groups, etc. Only one type of each of the above-mentioned other monomer components may be used, or two or more types may be used.

Examples of the above carboxyl group-containing monomer include: acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, butyl Acrylic acid etc. Examples of the acid anhydride monomer include maleic anhydride, itaconic anhydride, and the like.

Examples of the hydroxyl-containing monomer include: (meth)acrylic acid 2-hydroxyethyl ester, (meth)acrylic acid 2-hydroxypropyl ester, (meth)acrylic acid 4-hydroxybutyl ester, (meth)acrylic acid 4-hydroxybutyl ester, (meth)acrylic acid 2-hydroxyethyl 6-hydroxyhexyl acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethyl)acrylate cyclohexyl) methyl ester, etc.

Examples of the glycidyl group-containing monomer include: glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, and the like.

Examples of the above-mentioned sulfonic acid group-containing monomer include: styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, and (meth)acrylamide. Aminopropyl sulfonic acid, (meth)acrylic acid sulfopropyl ester, (meth)acryloyloxynaphthalene sulfonic acid, etc.

Examples of the phosphoric acid group-containing monomer include 2-hydroxyethylacrylyl phosphate and the like.

The above-mentioned nitrogen atom-containing monomer is a monomer having at least one nitrogen atom in the molecule (within one molecule). The above-mentioned nitrogen atom-containing monomer is not particularly limited, and preferred examples thereof include: cyclic nitrogen-containing monomers, (meth)acrylamides, and the like. Furthermore, only one type of nitrogen atom-containing monomer may be used, or two or more types may be used.

The above-mentioned cyclic nitrogen-containing monomer is not particularly limited as long as it contains a polymerizable functional group having an unsaturated double bond such as a (meth)acryl group or a vinyl group and has a cyclic nitrogen structure. The above-mentioned cyclic nitrogen structure preferably has a nitrogen atom in the cyclic structure.

Examples of the cyclic nitrogen-containing monomer include N-vinyl cyclic amide (lactam vinyl monomer), vinyl monomers having nitrogen-containing heterocycles, and the like.

Examples of the N-vinyl cyclic amide include N-vinyl cyclic amide represented by the following formula (1). [Chemical 1] (In formula (1), R ¹ represents a divalent organic group)

R ¹ in the above formula (1) is a divalent organic group, preferably a divalent saturated hydrocarbon group or an unsaturated hydrocarbon group, more preferably a divalent saturated hydrocarbon group (for example, an alkylene group having 3 to 5 carbon atoms, etc.).

Examples of the N-vinyl cyclic amide represented by the above formula (1) include N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, N-vinyl- 3-𠰌linone, N-vinyl-2-caprolactam, N-vinyl-1,3-㗁𠯤-2-one, N-vinyl-3,5-𠰌lindione, etc.

Examples of the vinyl monomer having a nitrogen-containing heterocycle include acrylic monomers having a nitrogen-containing heterocycle such as a pyridine ring, a piperidine ring, a pyrrolidine ring, a piperidine ring, and the like.

The above-mentioned vinyl monomer having a nitrogen-containing heterocycle is not particularly limited, and examples thereof include: (meth)acrylamide, N-vinyl piperazole, N-vinylpyrrole, N-vinylimidazole, N -Vinylpyridine, N-vinylpyridine, N-vinylpyrazole, vinylpyridine, vinylpyrimidine, vinylethazole, vinylisethazole, vinylthiazole, vinylisothiazole, vinyl Acrylic acid, (meth)acrylylpyrrolidine, (meth)acrylylpyrrolidine, (meth)acrylylpiperidine, etc.

Examples of the (meth)acrylamides include (meth)acrylamide, N-alkyl(meth)acrylamide, and N,N-dialkyl(meth)acrylamide. wait. Examples of the N-alkyl(meth)acrylamide include N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-n-butyl( Meth)acrylamide, N-octyl(meth)acrylamide, etc. Furthermore, the above-mentioned N-alkyl (meth)acrylamide also includes dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, and dimethylaminopropyl (Meth)acrylamide, such as (meth)acrylamide, has an amine group. Examples of the N,N-dialkyl(meth)acrylamide include N,N-dimethyl(meth)acrylamide and N,N-diethyl(meth)acrylamide. Amine, N,N-dipropyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, N,N-di(n-butyl)(meth)acrylamide , N,N-di(tert-butyl)(meth)acrylamide, etc.

In addition, the above-mentioned (meth)acrylamides also include various N-hydroxyalkyl (meth)acrylamides, for example. Examples of the N-hydroxyalkyl(meth)acrylamide include N-hydroxymethyl(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, N-(2-hydroxypropyl)(meth)acrylamide, N-(1-hydroxypropyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide , N-(2-hydroxybutyl)(meth)acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, N-(4-hydroxybutyl)(meth)acrylamide Amine, N-methyl-N-2-hydroxyethyl (meth)acrylamide, etc.

In addition, the above-mentioned (meth)acrylamides also include various N-alkoxyalkyl (meth)acrylamides, for example. Examples of the N-alkoxyalkyl(meth)acrylamide include N-methoxymethyl(meth)acrylamide and N-butoxymethyl(meth)acrylamide. Amines etc.

In addition, examples of nitrogen atom-containing monomers other than the above-mentioned cyclic nitrogen-containing monomers and the above-mentioned (meth)acrylamides include: amine group-containing monomers, cyano group-containing monomers, and Imide-based monomers, isocyanate-containing monomers, etc. Examples of the above-mentioned amine group-containing monomer include: (meth)aminoethyl acrylate, (meth)acrylic acid dimethylaminoethyl, (meth)acrylic acid dimethylaminopropyl, (meth)acrylate base) tert-butylaminoethyl acrylate, etc. Examples of the cyano group-containing monomer include acrylonitrile, methacrylonitrile, and the like. Examples of the above-mentioned amide group-containing monomer include maleimide monomers (for example, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylimide, etc.). methyl maleimide, N-phenyl maleimide, etc.), itonimide monomers (for example, N-methyl itonimide, N-ethyl itonimide, N-butyliconimide, N-octyliconimide, N-2-ethylhexyliconimide, N-lauryl itonimide, N-cyclohexyliconimide imine, etc.), succinimide-based monomers (for example, N-(meth)acryloxymethylenesuccinimide, N-(meth)acrylyl-6-oxyhexane Methylene succinimide, N-(meth)acryl-8-oxyoctamethylene succinimide, etc.). Examples of the isocyanate group-containing monomer include 2-(meth)acryloyloxyethyl isocyanate.

Among them, as the above-mentioned nitrogen atom-containing monomer, a cyclic nitrogen-containing monomer is preferred, and an N-vinyl cyclic amide is more preferred. More specifically, N-vinyl-2-pyrrolidone (NVP) and N-vinyl-2-caprolactam are particularly preferred.

It is preferable to contain a hydroxyl group-containing monomer and/or a nitrogen atom-containing monomer as the polar group-containing monomer constituting the acrylic polymer. By using this polar group-containing monomer, the cohesion or polarity of the adhesive can be adjusted, thereby improving the adhesive force after heating.

When the above-mentioned acrylic polymer contains the above-mentioned hydroxyl-containing monomer as a monomer component constituting the polymer, the proportion of the above-mentioned hydroxyl-containing monomer in the total monomer components (100% by mass) constituting the above-mentioned acrylic polymer The ratio is not particularly limited, but it is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more, still more preferably 1% by mass or more, still more preferably 5% by mass or more, especially Preferably, it is 10 mass % or more. In addition, from the viewpoint of improving the tackiness at normal temperature (25°C) or improving the softness at low temperature, the ratio of the above-mentioned nitrogen atom-containing monomer is preferably 40 mass % or less, and more preferably 30 mass %. % or less, more preferably 20 mass% or less, and may be 10 mass% or less or 5 mass% or less.

When the acrylic polymer contains the nitrogen-containing monomer as a monomer component constituting the polymer, the nitrogen-containing monomer in all monomer components (100 mass %) constituting the acrylic polymer The ratio of solids is not particularly limited, but is preferably 0.01 mass% or more, more preferably 0.1 mass% or more, further preferably 0.5 mass% or more, further preferably 1 mass% or more, still more preferably 5 mass% or more , the best value is more than 10% by mass. In addition, from the viewpoint of improving the tackiness at normal temperature (25°C) or improving the softness at low temperature, the ratio of the above-mentioned nitrogen atom-containing monomer is preferably 40 mass % or less, and more preferably 30 mass %. % or less, and more preferably 20 mass% or less.

The total ratio of the above-mentioned polar group-containing monomers (especially the total of the above-mentioned nitrogen atom-containing monomers and the above-mentioned hydroxyl group-containing monomers) among all the monomer components (100% by mass) constituting the above-mentioned acrylic polymer has no Specifically limited, from the viewpoint of better exerting the effect obtained by using the polar group-containing monomer, it is preferably 0.1 mass% or more, more preferably 1 mass% or more, and still more preferably 5 mass% or more. It may be 10 mass% or more, 15 mass% or more, 20 mass% or more, or 25 mass% or more. Moreover, from the viewpoint of obtaining an adhesive layer having moderate flexibility, the total of the above ratios is preferably 50 mass% or less, and more preferably 40 mass% or less.

As the monomer component constituting the acrylic polymer, other monomers may be further included. Examples of the other monomers include vinyl ester monomers such as vinyl acetate, vinyl propionate, and vinyl laurate; styrene, substituted styrene (α-methylstyrene, etc.), vinyl toluene and other aromatic vinyl compounds; olefin monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; chlorine-containing monomers such as vinyl chloride and vinylidene chloride; methoxyethyl (meth)acrylate , ethoxyethyl (meth)acrylate and other alkoxy group-containing monomers; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether, etc.

The ratio of the other monomers in the total amount of 100% by mass of all monomer components constituting the acrylic polymer may be, for example, 0.05% by mass or more or 0.5% by mass or more. The above-mentioned ratio may be, for example, 20 mass% or less, 10 mass% or less, or 5 mass% or less, or the other monomers described above may not be substantially contained.

The above-mentioned acrylic polymer can be obtained by polymerizing the above-mentioned various monomer components. The polymerization method is not particularly limited, and examples thereof include a solution polymerization method, an emulsion polymerization method, a block polymerization method, a polymerization method using active energy ray irradiation (active energy ray polymerization method), and the like. Moreover, the obtained acrylic polymer may be any of a random copolymer, a block copolymer, a graft copolymer, etc.

During the polymerization of monomer components, various general solvents can be used. Examples of the solvent include esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; cyclohexane and methylcyclohexane; alicyclic hydrocarbons such as alkanes; organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. Only one type of solvent may be used, or two or more types of solvents may be used.

The polymerization initiator, chain transfer agent, emulsifier, etc. used in the radical polymerization of the monomer components are not particularly limited and can be appropriately selected and used. Furthermore, the weight average molecular weight of the acrylic polymer can be controlled by the usage amounts of polymerization initiators and chain transfer agents and reaction conditions, and the usage amounts can be appropriately adjusted according to their types.

As a polymerization initiator used for polymerization of monomer components, a thermal polymerization initiator or a photopolymerization initiator (photoinitiator), etc. can be used depending on the type of polymerization reaction. Only one type of the above-mentioned polymerization initiator may be used, or two or more types may be used.

The thermal polymerization initiator is not particularly limited, and examples thereof include azo polymerization initiators, peroxide polymerization initiators (for example, dibenzoyl peroxide, maleic acid peroxide). Persulfates such as tributyl ester, potassium persulfate; benzoyl peroxide, hydrogen peroxide, etc.), substituted ethane-based initiators such as phenyl-substituted ethane, aromatic carbonyl compounds, redox-based polymerization initiators wait. Among them, the azo polymerization initiator disclosed in Japanese Patent Application Laid-Open No. 2002-69411 is preferred. Examples of the azo polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, and 2,2'-azobis. (2-Methylpropionic acid) dimethyl ester, 4,4'-azobis-4-cyanovaleric acid, etc. The thermal polymerization initiator may be used in a normal amount, and may be selected from a range of, for example, 0.01 to 5 parts by mass, preferably 0.05 to 3 parts by mass, based on 100 parts by mass of the monomer component.

The above-mentioned photopolymerization initiator is not particularly limited, and examples thereof include benzoin ether-based photopolymerization initiator, acetophenone-based photopolymerization initiator, α-ketool-based photopolymerization initiator, and aromatic sulfonyl initiator. Chlorine-based photopolymerization initiator, photoactive oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzoyl-based photopolymerization initiator, benzophenone-based photopolymerization initiator, ketal-based photopolymerization initiator Photopolymerization initiator, 9-oxosulfide𠮿 It is a photopolymerization initiator, etc. In addition, examples include phosphine oxide-based photopolymerization initiators and titanocene-based photopolymerization initiators. Examples of the benzoin ether photopolymerization initiator include: benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and 2,2-dimethoxy-1,2- Diphenylethane-1-one, anisole methyl ether, etc. Examples of the acetophenone-based photopolymerization initiator include: 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, and 1-hydroxyacetophenone. Hexyl phenyl ketone, 4-phenoxydichloroacetophenone, 4-(tert-butyl)dichloroacetophenone, etc. Examples of the α-ketool photopolymerization initiator include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropane. -1-one etc. Examples of the aromatic sulfonyl chloride-based photopolymerization initiator include 2-naphthalene sulfonyl chloride and the like. Examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,1-propanedione-2-(O-ethoxycarbonyl)-oxime. Examples of the benzoin-based photopolymerization initiator include benzoin and the like. Examples of the benzilyl-based photopolymerization initiator include benzilyl and the like. Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoyl benzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, and polyethylene. Benzophenone, α-hydroxycyclohexyl phenyl ketone, etc. Examples of the ketal-based photopolymerization initiator include benzyl dimethyl ketal and the like. As the above 9-oxosulfide𠮿 It is a photopolymerization initiator, for example: 9-oxosulfide , 2-chloro-9-oxosulfide𠮿 , 2-Methyl 9-oxosulfide𠮿 , 2,4-dimethyl 9-oxosulfide𠮿 , isopropyl 9-oxosulfide𠮿 , 2,4-diisopropyl 9-oxosulfide𠮿 , dodecyl 9-oxosulfide𠮿 wait. Examples of the above-mentioned phosphine oxide-based photopolymerization initiator include: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethyl Benzyl)-phenylphosphine oxide, etc. Examples of the titanocene-based photopolymerization initiator include bis(eta ⁵ -2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole) -1-yl)-phenyl) titanium, etc. The photopolymerization initiator may be used in a normal amount, and may be selected from a range of, for example, 0.01 to 5 parts by mass, preferably 0.05 to 3 parts by mass, based on 100 parts by mass of the monomer component.

The above-mentioned acrylic polymer can be obtained by irradiating ultraviolet (UV) rays to a monomer composition in which a polymerization initiator is blended with the monomer components as described above to partially polymerize the monomer components. The form of (acrylic polymer slurry) is included in the adhesive composition for forming the adhesive layer. The adhesive composition containing the above-mentioned acrylic polymer slurry can be coated on a coated object such as a metal substrate or a release liner, and then irradiated with ultraviolet rays to complete polymerization. That is, the acrylic polymer slurry may be an acrylic polymer precursor. The adhesive layer can be formed, for example, using an adhesive composition containing the acrylic polymer slurry, polymer (B), and phenolic antioxidant.

(Polymer (B)) The polymer (B) contains a monomer (B1) having a polyorganosiloxane skeleton and a monomer (B2) having a homopolymer with a glass transition temperature of 40° C. or above as monomer units.

The monomer (B1) having a polyorganosiloxane skeleton constituting the polymer (B) is not particularly limited, and any monomer containing a polyorganosiloxane skeleton can be used. Monomer (B1) has low polarity due to its structure, so it actively promotes the uneven distribution of polymer (B) on the surface of the adherend, showing easy peelability in the early stage of lamination.

Examples of the monomer having a polyorganosiloxane skeleton that can be used as the monomer (B1) include a compound represented by the following formula (2) and a compound represented by the following formula (3). More specifically, examples include: product name "X-22-174ASX", product name "X-22-2475", product name "X-22-174DX", product name "X-22-2426", product name Single-terminal reactive polysiloxane oils such as "KF-2012" (above, manufactured by Shin-Etsu Chemical Industry Co., Ltd.). Only one type of monomer (B1) may be used, or two or more types may be used.

[Chemicalization 2] [In formulas (2) and (3), R ² represents a hydrogen atom or a methyl group, R ³ represents a monovalent organic group, and m and n each independently represent an integer above 0]

Examples of the monovalent organic group include linear or branched hydrocarbon groups. The above-mentioned hydrocarbon groups are saturated or unsaturated hydrocarbon groups. The number of carbon atoms in the above-mentioned monovalent organic group is preferably 1 to 10, more preferably 1 to 4. As the above-mentioned monovalent organic group, preferred ones include methyl, ethyl, propyl (n-propyl, isopropyl), and butyl (n-butyl, tert-butyl, etc.).

The functional group equivalent of monomer (B1) is 1000 g/mol or more and less than 15000 g/mol. If the functional group equivalent weight is less than 1000 g/mol, it may not be easy to peel off and the adhesive force may not be reduced in the initial stage of lamination. In addition, if the functional group equivalent is 15000 g/mol or more, the compatibility with the polymer (A) may significantly deteriorate, and the adhesive force may not decrease in the initial stage of bonding to the adherend, or the adhesive force may increase over time. Poor sexual performance.

Here, "functional group equivalent" means the mass of the main skeleton (eg, polydimethylsiloxane) bonded to each functional group. Regarding the labeling unit g/mol, it is converted into 1 mol of functional group. The functional group equivalent of the monomer having a polyorganosiloxane skeleton can be calculated, for example, based on the spectral intensity of ¹ H-NMR (proton NMR) obtained by nuclear magnetic resonance (NMR) analysis.

By ¹ H-NMR, the spectral intensity of H of silicon bonded to the siloxane structure via C (for example, H of Si-(CH ₃ ) ₂ ) and the H of C-CH ₃ and SH of the functional group are determined. The ratio of the spectral intensity of H, or C=CH ₂ . Take the case of finding the ratio of the spectral intensity of H of Si-(CH ₃ ) ₂ of the siloxane structure to the spectral intensity of C=CH ₂ of the functional group as an example to illustrate. According to the spectral intensity ratio, it can be seen that the measurement test The ratio of the number of Si-(CH ₃ ) ₂ in the siloxane structure contained in the sample to the number of C=CH ₂ in the functional group. Since the chemical formula of the siloxane structure and the chemical formula of the functional group are known in advance, the measurement test can be determined based on the ratio of the number of Si-(CH ₃ ) ₂ in the siloxane structure to the number of C=CH ₂ in the functional group. The ratio of the number A of siloxane structures with Si-(CH ₃ ) ₂ bonds to the number B of functional groups contained in the sample (A/B). The molecular weight of each siloxane structure (here, dimethylsiloxane) with Si-(CH ₃ ) ₂ bonds is known. Therefore, the molecular weight of each siloxane structure is multiplied by the number of the above siloxane structures. The value obtained by the ratio of A to the number of functional groups (A/B) is the mass of the siloxane structure with Si-(CH ₃ ) ₂ bonds for each functional group, that is, the mass of the main skeleton, and its mass is multiplied by The value obtained from Avogadro's constant is the functional group equivalent (g/mol).

Furthermore, when two or more monomers having a polyorganosiloxane skeleton with different functional group equivalents are used, as for the functional group equivalent of the monomer (B1), the above two or more types of polyorganosiloxane skeletons are used. The value obtained by the arithmetic average of the functional group equivalents of the monomers of the oxyalkane skeleton. For example, when n types of monomers (monomer 1, monomer 2, ... monomer n) having a polyorganosiloxane skeleton are used, the value calculated using the following formula is set as monomer (B1) Functional group equivalent. The functional group equivalent of monomer (B1) (g/mol) = (the functional group equivalent of monomer 1 × the blending amount of monomer 1 + the functional group equivalent of monomer 2 × the blending amount of monomer 2 +... + monomer The functional group equivalent of n×the blending amount of monomer n)/(the blending amount of monomer 1+the blending amount of monomer 2+...+the blending amount of monomer n)

Regarding the ratio of the monomer (B1) among the total monomer components constituting the polymer (B), from the viewpoint of exerting a moderate initial adhesive force and better exerting the effect as an adhesive force increase delaying agent, It is preferably 5 mass% or more, more preferably 10 mass% or more, further preferably 15 mass% or more, particularly preferably 20 mass% or more, relative to the total amount (100 mass%) of all the above-mentioned monomer components. Regarding the ratio of the above-mentioned monomer (B1), from the viewpoint of excellent polymerization reactivity or compatibility, and further excellent increase in adhesive force over time, it is based on the total amount of all the above-mentioned monomer components (100% by mass) , preferably 60 mass% or less, more preferably 50 mass% or less, further preferably 40 mass% or less, particularly preferably 30 mass% or less.

Regarding the monomer (B2) constituting the polymer (B), the glass transition temperature of the homopolymer is 40°C or higher, preferably 80°C or higher, and more preferably 100°C or higher. Only one type of monomer (B2) may be used, or two or more types may be used.

Examples of the monomer (B2) include an acrylic monomer or a polar group-containing monomer. That is, examples of the monomer (B2) include monomers in which the glass transition temperature of the homopolymer among the above-mentioned acrylic monomers and polar group-containing monomers is 40° C. or higher.

Regarding the monomer (B2) as the acrylic monomer, (meth)acrylate having a hydrocarbon group is preferred, and alkyl (meth)acrylate having a linear or branched aliphatic hydrocarbon group is more preferred. (Meth)acrylate with alicyclic hydrocarbon group.

Examples of the monomer (B2) as an acrylic monomer include: dicyclopentyl methacrylate (Tg: 175°C), dicyclopentyl acrylate (Tg: 120°C), isopropyl methacrylate ( Tg: 173℃), isopropyl acrylate (Tg: 97℃), methyl methacrylate (Tg: 105℃), 1-adamantyl methacrylate (Tg: 250℃), 1-adamantyl acrylate Alkyl ester (Tg: 153°C), etc.

Examples of the monomer (B2) that is a polar group-containing monomer include acryloline (Tg: 145°C), dimethacrylamide (Tg: 119°C), diethylacrylamide ( Tg: 81℃), dimethylaminopropylacrylamide (Tg: 134℃), isopropylacrylamide (Tg: 134℃), hydroxyethylacrylamide (Tg: 98℃), etc. Amine-based monomers; N-vinyl-2-caprolactam and other lactam monomers such as N-vinyl caprolactam and other nitrogen-containing monomers.

When the monomer (B2) is a polar group-containing monomer, the polymer (B) preferably contains, in addition to the monomer (B1) and the monomer (B2), an acrylic monomer as a constituent polymer ( B) monomer components.

Regarding the ratio of the monomer (B2) among all the monomer components constituting the polymer (B), from the viewpoint of exerting a moderate initial adhesive force and better exerting the effect as an adhesive force increase delaying agent, It is preferably 10 mass% or more, more preferably 20 mass% or more, and still more preferably 30 mass% or more relative to the total amount (100 mass%) of all the above-mentioned monomer components. If the above ratio is 10% by mass or more, the initial adhesive force is likely to decrease. Regarding the ratio of the above-mentioned monomer (B2), from the viewpoint of excellent polymerization reactivity or compatibility, and further excellent increase in adhesive force over time, it is based on the total amount of all the above-mentioned monomer components (100% by mass) , preferably 80 mass% or less, more preferably 60 mass% or less, further preferably 50 mass% or less.

As the monomer component constituting the polymer (B), other monomers may be included in addition to the monomer (B1) and the monomer (B2). Examples of the above-mentioned other monomers include those other than the monomer (B1) and the monomer (B2) in the above examples and descriptions of the monomers constituting the acrylic polymer. The above-mentioned other monomers are preferably monomers including homopolymers with a glass transition temperature of less than 40° C. (sometimes referred to as “monomer (B3)”). The glass transition temperature of the homopolymer of monomer (B3) is less than 40°C, preferably 35°C or less, more preferably 30°C or less. Only one type of monomer (B3) may be used, or two or more types may be used.

Examples of the monomer (B3) include acrylic monomers. That is, the monomer (B3) may be a monomer in which the glass transition temperature of the homopolymer among the above-mentioned acrylic monomers is less than 40°C. Examples of the acrylic monomer (B3) include methacrylic acid such as butyl methacrylate (Tg: 20°C) and 2-ethylhexyl methacrylate (Tg: -10°C). Alkyl esters, etc.

The ratio of the monomer (B3) among all the monomer components constituting the polymer (B) is preferably 10 mass% or more, more preferably 20 mass% relative to the total amount of all the above-mentioned monomer components (100 mass%) or more, and more preferably 30% by mass or more. The above ratio is preferably 85 mass% or less, more preferably 70 mass% or less, further preferably 55 mass% or less, particularly preferably 50 mass% or less, based on the total amount (100 mass%) of all the above-mentioned monomer components. .

The total ratio of the monomer (B1) and the monomer (B2) among all the monomer components constituting the polymer (B) is preferably 15 mass% or more relative to the total amount of all the above-mentioned monomer components (100 mass%) , more preferably 30 mass% or more, still more preferably 45 mass% or more, and particularly preferably 50 mass% or more. The above total ratio is preferably 90 mass% or less, more preferably 80 mass% or less, and still more preferably 70 mass% or less relative to the total amount (100 mass%) of all the above-mentioned monomer components.

The weight average molecular weight of the polymer (B) is 10,000 or more and less than 100,000, preferably 12,000 or more and less than 50,000, more preferably 15,000 or more and less than 30,000. If the weight average molecular weight of the polymer (B) is 100,000 or more, the adhesive strength in the initial stage of bonding will not be reduced. In addition, if the weight average molecular weight is less than 10,000, the molecular weight is low, so the adhesive force of the adhesive sheet may not increase with time.

The polymer (B) can be obtained, for example, by polymerizing the various monomer components described above. The polymerization method is not particularly limited, and examples include a solution polymerization method, an emulsion polymerization method, a block polymerization method, a polymerization method using active energy ray irradiation (active energy ray polymerization method), and the like.

In the above polymerization, a chain transfer agent can be used to adjust the molecular weight of polymer (B). Examples of the chain transfer agent include compounds having mercapto groups such as octyl mercaptan, lauryl mercaptan, tertiary nonyl mercaptan, tertiary dodecyl mercaptan, mercaptoethanol, α-thioglycerol and the like; thioglycolic acid , methyl thioglycolate, ethyl thioglycolate, propyl thioglycolate, butyl thioglycolate, tert-butyl thioglycolate, 2-ethylhexyl thioglycolate, sulfide Octyl glycolate, isooctyl thioglycolate, decyl thioglycolate, dodecyl thioglycolate, thioglycolate of ethylene glycol, thioglycolate of neopentyl glycol , thioglycolic acid esters such as pentaerythritol thioglycolic acid ester; α-methylstyrene dimer, etc. Only one type of the above-mentioned chain transfer agent may be used, or two or more types may be used.

The usage amount of the above chain transfer agent is, for example, 0.05 to 20 parts by mass, preferably 0.1 to 15 parts by mass, and more preferably 0.2 to 10 parts by mass relative to 100 parts by mass of the monomer component.

The content of the polymer (B) in the adhesive layer is 0.1 to 20 parts by mass, preferably 0.3 to 25 parts by mass, and more preferably 0.4 to 20 parts by mass relative to 100 parts by mass of the total amount of polymer (A). parts, more preferably 0.5 to 15 parts by mass, still more preferably 1 to 10 parts by mass, particularly preferably 2 to 7 parts by mass. By setting the above content to 0.1 parts by mass or more, secondary processability is excellent. By making the above content 20 parts by mass or less, higher adhesive force can be achieved after heating.

The above-mentioned adhesive layer may contain polymers other than polymer (A) and polymer (B) within the scope that does not impair the effects of the present invention. The content ratio of the other polymers is preferably 20 mass% or less, more preferably 15 mass% or less, and still more preferably 10 mass% or less based on 100 mass% of the total amount of polymer components contained in the adhesive layer. , it may be 5 mass% or less, 3 mass% or less, or 1 mass% or less. The above-mentioned adhesive layer is preferably an adhesive layer that does not substantially contain the above-mentioned other polymers.

(phenolic antioxidant) The above-mentioned adhesive layer contains a phenolic antioxidant in addition to the polymer (A) and the polymer (B). It is speculated that the above-mentioned phenolic antioxidant has the function of capturing components that may become outgassing in the above-mentioned adhesive layer, and by containing a specific amount or more of the phenolic antioxidant, the total amount of outgassing of the adhesive layer is reduced. Only one type of the above-mentioned phenolic antioxidant may be used, or two or more types may be used.

The number of phenolic skeletons in the above-mentioned phenolic antioxidant is not particularly limited. It is 1 or more (for example, 1 to 10), preferably 2 or more, more preferably 3 or more, and still more preferably 4 or more. If the number of the above-mentioned phenolic skeletons is larger, the total gas release amount will further decrease.

Specific examples of the phenolic antioxidant include: 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-p-cresol, Dicyclohexyl-4-methylphenol, 2,6-diisopropyl-4-ethylphenol, 2,6-di-3-pentyl-4-methylphenol, 2,6-di-3-octyl -4-n-propylphenol, 2,6-dicyclohexyl-4-n-octylphenol, 2-isopropyl-4-methyl-6-tert-butylphenol, 2-tert-butyl-4 -Ethyl-6-tert-octylphenol, 2-isobutyl-4-ethyl-6-tert-hexylphenol, 2-cyclohexyl-4-n-butyl-6-isopropylphenol, styrene Chemical mixed cresol, DL-α-tocopherol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)stearyl propionate, 2,6-di-tert-butyl-4 -(4,6-Bis(octylthio)-1,3,5-tri𠯤-2-yl-amino)phenol and other compounds with one phenolic skeleton (monocyclic phenolic compounds); 2,2'- Methylene bis(4-methyl-6-tert-butylphenol), 4,4'-butylene bis(3-methyl-6-tert-butylphenol), 4,4'-thiobis (3-methyl-6-tert-butylphenol), 2,2'-thiobis(4-methyl-6-tert-butylphenol), 4,4'-methylenebis(2, 6-di-tert-butylphenol), 2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol], 2,2'-ethylenebis(4,6- Di-tert-butylphenol), 2,2'-butylenebis(2-tert-butyl-4-methylphenol), 3,6-dioxaoctamethylenebis[3-(3-th Tributyl-4-hydroxy-5-methylphenyl)propionate], triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate ], 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2'-thiodiethylene bis[3 -(3,5-Di-tert-butyl-4-hydroxyphenyl)propionate] and other compounds with two phenolic skeletons (2-ring phenol compounds); 1,1,3-tris(2-methyl) -4-Hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl)isocyanuric acid Ester, 1,3,5-tris[(3,5-di-tert-butyl-4-hydroxyphenyl)propyloxyethyl]isocyanurate, tris(4-tert-butyl- 2,6-Dimethyl-3-hydroxybenzyl)isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4 -Hydroxybenzyl)benzene and other compounds with 3 phenolic skeletons (3-ring phenol compounds); tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate ]Methane and other compounds with 4 phenolic skeletons (4-ring phenol compounds); bis(3,5-di-tert-butyl-4-hydroxybenzylphosphonate ethyl ester) calcium, bis(3,5-di- Phosphorus-containing phenolic compounds such as ethyl tert-butyl-4-hydroxybenzylphosphonate) nickel, etc.

The content of the phenolic antioxidant in the adhesive layer is 0.4 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 0.7 parts by mass or more based on 100 parts by mass of the total amount of polymer (A). By making the above content 0.4 parts by mass or more, the total outgassing amount of the adhesive sheet is reduced. The above content is preferably less than 5 parts by mass, more preferably 4 parts by mass or less, and still more preferably 3 parts by mass or less. If the above content is less than 5 parts by mass, segregation on the surface of the adhesive layer is less likely to occur, thereby causing solidification of the surface of the adhesive layer or a reduction in the adhesive force after heating due to its influence. Furthermore, it has excellent dispersibility in the adhesive composition forming the adhesive layer.

Polymer (A) and polymer (B) can be cross-linked by a cross-linking agent. By using a cross-linking agent, a cross-linked structure can be formed in the polymer component in the adhesive layer to control cohesion. The cross-linking agent can be appropriately selected according to the functional groups that polymer components such as polymer (A) or polymer (B) have on their side chains. Only one type of cross-linking agent may be used, or two or more types of cross-linking agents may be used.

The above-mentioned cross-linking agent is not particularly limited, and examples thereof include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, melamine-based cross-linking agents, peroxide-based cross-linking agents, urea-based cross-linking agents, and metal alkoxides. Physical cross-linking agent, metal chelate cross-linking agent, metal salt cross-linking agent, carbodiimide cross-linking agent, oxazoline cross-linking agent, aziridine cross-linking agent, amine cross-linking agent Cross-linking agent, hydrazine-based cross-linking agent, silicone-based cross-linking agent, silane-based cross-linking agent (silane coupling agent), etc. The cross-linking agent preferably contains an isocyanate-based cross-linking agent.

The content of the cross-linking agent is not particularly limited, but is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and still more preferably 0.1 parts by mass or more, based on 100 parts by mass of the total amount of polymer (A). More preferably, it is 0.5 parts by mass or more, and particularly preferably, it is 1 part by mass or more. If the content is 0.01 parts by mass or more, the secondary processability will be further excellent. In addition, the content of the cross-linking agent is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and still more preferably 5 parts by mass or less.

The isocyanate cross-linking agent is a compound (polyfunctional isocyanate compound) having an average of two or more isocyanate groups per molecule. Examples of the isocyanate-based crosslinking agent include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and the like.

Examples of the aliphatic polyisocyanates include: 1,2-ethylidene diisocyanate; 1,2-tetramethylene diisocyanate, 1,3-tetramethylene diisocyanate, 1,4-tetrakis Tetramethylene diisocyanate such as methylene diisocyanate; 1,2-hexamethylene diisocyanate, 1,3-hexamethylene diisocyanate, 1,4-hexamethylene diisocyanate, 1,5- Hexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,5-hexamethylene diisocyanate and other hexamethylene diisocyanates; 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate; lysine diisocyanate, etc.

Examples of the alicyclic polyisocyanates include isophorone diisocyanate; cyclohexyl diisocyanate such as 1,2-cyclohexyl diisocyanate, 1,3-cyclohexyl diisocyanate, and 1,4-cyclohexyl diisocyanate. Diisocyanates; cyclopentyl diisocyanates such as 1,2-cyclopentyl diisocyanate and 1,3-cyclopentyl diisocyanate; hydrogenated xylylene diisocyanate, hydrogenated toluene diisocyanate, hydrogenated diphenylmethane diisocyanate, Hydrogenated tetramethylxylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, etc.

Examples of the aromatic polyisocyanates include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and 2,4'-diphenylmethane. Diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenyl Propane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, isophthalic diisocyanate, p-phenylene Diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, xylylenedimethyl -1,4-diisocyanate, xylylenedimethyl-1,3-diisocyanate, etc.

Examples of the isocyanate cross-linking agent include: trimethylolpropane/toluene diisocyanate adduct (trade name "Coronate L", manufactured by Tosoh Co., Ltd.), trimethylolpropane/ Hexamethylene diisocyanate adduct (trade name "Coronate HL", manufactured by Tosoh Co., Ltd.), trimethylolpropane/xylylene diisocyanate adduct (trade name "Takenate D-110N", (manufactured by Mitsui Chemicals Co., Ltd.) and other commercially available products.

Examples of the above-mentioned epoxy cross-linking agent (polyfunctional epoxy compound) include: N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1, 3-Bis(N,N-diglycidylaminemethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether Glycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether Glycidyl ether, trimethylolpropane polyglycidyl ether, diglycidyl adipate, diglycidyl phthalate, triglycidyl-tris(2-hydroxyethyl)isocyanurate, In addition to resorcinol diglycidyl ether and bisphenol-S-diglycidyl ether, epoxy resins having two or more epoxy groups in the molecule may be used. Examples of the epoxy cross-linking agent include commercially available products such as the trade name "Tetrad C" (manufactured by Mitsubishi Gas Chemical Co., Ltd.).

As the above-mentioned peroxide cross-linking agent, any one that generates radical active species by heat and promotes the cross-linking of the base polymer can be used appropriately. In consideration of workability and stability, it is preferable to use a half-life temperature of 1 minute. The peroxide is a peroxide of 80 to 160°C, and more preferably a peroxide with a half-life temperature of 90 to 140°C in 1 minute is used.

Examples of the peroxide-based cross-linking agent include di(2-ethylhexyl) peroxydicarbonate (1-minute half-life temperature: 90.6°C), di(4-tert-butyl peroxydicarbonate) Cyclohexyl) ester (half-life temperature in 1 minute: 92.1°C), dibutyl peroxydicarbonate (half-life temperature in 1 minute: 92.4°C), tert-butyl peroxyneodecanoate (half-life temperature in 1 minute: 103.5°C) ), tert-hexyl pivalate peroxide (half-life temperature in 1 minute: 109.1°C), tert-butyl pivalate peroxide (half-life temperature in 1 minute: 110.3°C), dilauryl peroxide (half-life temperature in 1 minute) : 116.4℃), di-n-octyl peroxide (half-life temperature in 1 minute: 117.4℃), 1,1,3,3-tetramethylbutyl peroxide 2-ethylhexanoate (half-life temperature in 1 minute: 124.3℃) ), dibenzoyl peroxide (1-minute half-life temperature: 128.2°C), dibenzoyl peroxide (1-minute half-life temperature: 130.0°C), tert-butyl peroxide isobutyrate ( 1-minute half-life temperature: 136.1°C), 1,1-di(tertiary hexylperoxy)cyclohexane (1-minute half-life temperature: 149.2°C), etc.

The half-life of the above-mentioned peroxide cross-linking agent is an index indicating the decomposition rate of the peroxide, and refers to the time until the remaining amount of the peroxide becomes half. The decomposition temperature used to obtain the half-life at any point in time, or the half-life time at any temperature, is described in manufacturers' catalogs, etc., for example, "Organic Peroxide Catalog 9th Edition (2003) of NOF Co., Ltd. May 2016)" etc. In addition, as a method for measuring the decomposition amount of peroxide remaining after the reaction treatment, HPLC (high performance liquid chromatography) can be used for measurement, for example. More specifically, for example, take out about 0.2 g of the reaction-treated adhesive in each case, immerse it in 10 ml of ethyl acetate, use a shaker to extract at 25°C and 120 rpm for 3 hours, and then place it at room temperature. Let sit for 3 days. Next, 10 ml of acetonitrile was added, shaken at 25°C and 120 rpm for 30 minutes, filtered with a membrane filter (0.45 μm) to obtain an extract, and about 10 μl of the extract was injected into HPLC for analysis, and was set to The amount of peroxide after reaction treatment.

Furthermore, as the cross-linking agent, an organic cross-linking agent or a polyfunctional metal chelate compound may be used together. Multifunctional metal chelates are formed by covalent bonding or coordination bonding between multivalent metals and organic compounds. Examples of polyvalent metal atoms include: Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti et al. Examples of the atom in the organic compound that undergoes covalent bonding or coordination bonding include oxygen atoms. Examples of the organic compound include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, ketone compounds, etc. .

The above-mentioned adhesive layer may also contain other components in addition to the above-mentioned components within the scope that does not impair the effects of the present invention. Examples of the above-mentioned other components include hardeners, cross-linking catalysts, adhesion-imparting resins, anti-aging agents, fillers (metal powder, organic fillers, inorganic fillers, etc.), and antioxidants other than phenolic antioxidants. , plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, UV absorbers, polymerization inhibitors, granules, foils, colorants (pigments, dyes etc. Only one type of each of the above-mentioned other components may be used, or two or more types may be used. Furthermore, relative to the total amount of antioxidants in the adhesive layer (100 mass%), the ratio of phenolic antioxidants is preferably 60 mass% or more, and may also be 70 mass% or more, 80 mass% or more, or 90 mass%. Above, 95 mass% or above, 99 mass% or above.

The above-mentioned adhesive layer may contain a cross-linking catalyst. If a cross-linking catalyst is included, the cross-linking reaction using a cross-linking agent or the like can be accelerated. As the cross-linking catalyst, a tin-based catalyst (especially dioctyltin dilaurate) is preferred. Only one type of the above-mentioned cross-linking catalyst may be used, or two or more types may be used. The content of the cross-linking catalyst is, for example, 0.0001 to 1 part by mass relative to 100 parts by mass of the polymer (A).

The adhesive layer may contain an adhesive imparting resin. If an adhesion-imparting resin is included, the adhesive layer will have better adhesion even if it is thin. Examples of the tackifier-imparting resin include phenol-based tackifier-imparting resin, terpene-based tackifier-imparting resin, rosin-based tackifier-imparting resin, hydrocarbon-based tackifier-imparting resin, epoxy-based tackifier-imparting resin, and polyamide-based tackifier-imparting resin. , elastic system adhesion-imparting resin, ketone-based adhesion-imparting resin, etc. Examples of the tackifier-imparting resin include oligomers of (meth)acrylic acid alkyl esters such as oligomers of dicyclopentyl methacrylate (DCPMA) and methyl methacrylate (MMA). Only one type of the above-mentioned tackifying resin may be used, or two or more types may be used.

Examples of the phenolic tackifier-imparting resin include terpene phenol resin, hydrogenated terpene phenol resin, alkyl phenol resin, and rosin phenolic resin. The above-mentioned terpene phenol resin is a polymer containing a terpene residue and a phenol residue. Examples thereof include: copolymers of terpenes and phenol compounds (terpene-phenol copolymer resin), terpene homopolymers or copolymers It is modified by phenol (phenol modified terpene resin). Examples of the terpenes constituting the terpene phenol resin include monoterpenes such as α-pinene, β-pinene, and limonene (d form, l form, d/l form (dipentene), etc.). The hydrogenated terpene phenol resin is a resin having a structure obtained by hydrogenating the above terpene phenol resin. The above-mentioned alkylphenol resin is a resin obtained from alkylphenol and formaldehyde (oil-based phenol resin). Examples of the alkylphenol resin include novolak type and resol type. The above-mentioned rosin phenolic resin is a phenol-modified product of rosin or various rosin derivatives described below. The rosin phenolic resin can be obtained, for example, by adding phenol to rosins or various rosin derivatives described below using an acid catalyst and thermally polymerizing the resin.

Examples of the terpene-based adhesive-imparting resin include polymers of terpenes (typically monoterpenes) such as α-pinene, β-pinene, d-limonene, l-limonene, and dipentene. The above-mentioned terpene polymer may be a homopolymer of one terpene, or a copolymer of two or more terpenes. Examples of terpene homopolymers include α-pinene polymer, β-pinene polymer, and dipentene polymer. The above-mentioned modified terpene-based adhesive imparting resin is obtained by modifying the above-mentioned terpene resin (modified terpene resin). Examples of the modified terpene resin include styrene-modified terpene resin, hydrogenated terpene resin, and the like.

Examples of the rosin-based tackifier-imparting resin include rosin-based and rosin derivative resins. Examples of the above-mentioned rosins include unmodified rosin (raw rosin) such as rosin gum, wood rosin, and tall oil rosin; these unmodified rosins are modified by hydrogenation, disproportionation, polymerization, etc. Modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, other chemically modified rosin, etc.), etc. Examples of the rosin derivative resin include the above-mentioned rosin derivatives. Examples of the rosin derivative resin include unmodified rosin esters, which are esters of unmodified rosin and alcohols, or modified rosin esters, which are esters of modified rosin and alcohols. Unsaturated fatty acid-modified rosin obtained by modifying rosin with fatty acid; unsaturated fatty acid-modified rosin ester obtained by modifying rosin ester with unsaturated fatty acid; rosin or any of the above-mentioned various rosin derivatives Rosin alcohols obtained by reduction treatment of carboxyl groups; rosins or metal salts of various rosin derivatives mentioned above, etc. Specific examples of the rosin esters include methyl ester of unmodified rosin or modified rosin, triethylene glycol ester, glycerol ester, pentaerythritol ester, and the like.

Examples of the hydrocarbon-based tackifier-imparting resin include aliphatic hydrocarbon-based resins, aromatic hydrocarbon-based resins, aliphatic cyclic hydrocarbon-based resins, aliphatic-aromatic petroleum resins (styrene-olefin-based copolymers, etc.) , aliphatic-alicyclic petroleum resin, hydrogenated hydrocarbon resin, benzofuran resin, benzofuran-indene resin, etc.

The above-mentioned adhesive layer can be in any form, for example, it can be emulsion type, solvent type (solution type), active energy ray curing type, hot melt type (hot melt type), etc. Among them, in terms of easily obtaining an adhesive layer with excellent productivity, a solvent-based or active energy ray-curable adhesive composition is preferred.

The thickness of the above-mentioned adhesive layer (the total thickness of the adhesive layer on one side) is not particularly limited. For example, it is 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, and still more preferably 8 μm or more. The thickness is, for example, 30 μm or less, preferably 15 μm or less. If the above thickness is 30 μm or less, the total gas release amount of the adhesive sheet can be reduced. Furthermore, when the above-mentioned adhesive sheet is a double-sided adhesive sheet, the thickness of the adhesive layer on both sides may be the same or different.

The above-mentioned adhesive layer can be in any form, for example, it can be emulsion type, solvent type (solution type), active energy ray curing type, hot melt type (hot melt type), etc. Among them, in terms of easily obtaining an adhesive layer with excellent productivity, a solvent-based or active energy ray-curable adhesive composition is preferred.

Examples of the active energy rays include ionizing radiation such as alpha rays, beta rays, gamma rays, neutron rays, and electron beams, or ultraviolet rays. Ultraviolet rays are particularly preferred. That is, the active energy ray curable adhesive layer is preferably an ultraviolet curable adhesive layer.

The above-mentioned adhesive layer can be formed by coating (coating) the adhesive composition used to form the adhesive layer on a coated object such as a metal substrate or a release liner, and drying and hardening the obtained adhesive composition layer. Manufacturing; or manufacturing by coating (coating) the above-mentioned adhesive composition on the object to be coated, and irradiating the obtained adhesive composition layer with active energy rays to harden it. In addition, heating and drying may be further performed if necessary. The above-mentioned adhesive composition preferably contains polymer (A), polymer (B), and phenolic antioxidant.

(adhesive sheet) The thickness of the above-mentioned adhesive sheet is preferably 10 to 350 μm, more preferably 13 to 100 μm. Furthermore, it is more preferable that it is 15-60 micrometer or more. If the thickness is 10 μm or more, the workability will be excellent. If the above thickness is 350 μm or less, the thickness of the adhesive sheet can be made even thinner. Furthermore, the thickness of the above-mentioned adhesive sheet refers to the thickness from one adhesive surface to the other adhesive surface, that is, the thickness of the adhesive body, and does not include the release liner.

The total outgassing amount of the adhesive sheet is preferably 15,500 ppm or less, more preferably 13,000 ppm or less, further preferably 10,000 ppm or less, particularly preferably 3,000 ppm or less. The smaller the above-mentioned total gas release amount, the better it is from the viewpoint of environmental protection. The above total gas release amount can be measured by heating a 5 cm ² size adhesive sheet at 200°C for 60 minutes with a headspace sampler, and injecting 1 mL of the heated gas phase into a gas chromatograph. More specifically, the measurement can be performed under the conditions described in the examples.

The surface resistance value of the metal substrate surface of the above-mentioned adhesive sheet is preferably 10 ^-1 Ω/cm ² or less, more preferably 10 ^-2 Ω/cm ² or less, and further preferably 10 ^-3 Ω/cm ² or less. Particularly preferred is 10 ^-4 Ω/cm ² or less. The above surface resistance value can be measured in a gas atmosphere with a temperature of 23°C and 50% RH, based on JIS K6911, using a URS probe, with an applied voltage of 10 V and an applied time of 10 seconds.

The above adhesive sheet is attached to the SUS304BA board and placed in an environment of 23°C for 30 minutes. The 180° peeling adhesive force (initial adhesive force) is preferably 4 N/25 mm or less, and more preferably 2 N/25 mm. or less, more preferably 0.5 N/25 mm or less, particularly preferably 0.3 N/25 mm or less. If the above-mentioned initial adhesion force is 4 N/25 mm or less, the secondary processability will be excellent. The above-mentioned initial adhesive force is preferably 0.05 N/25 mm or more from the viewpoint of not easily peeling off when attached to the adherend.

The above adhesive sheet is attached to the SUS304BA board and placed in an environment of 80°C for 5 minutes. The 180° peeling adhesive force (adhesive force after heating) is preferably 10 N/25 mm or more, and more preferably 15 N/25 mm or more, more preferably 18 N/25 mm or more, particularly preferably 20 N/25 mm or more.

The above-mentioned adhesive sheet can be pasted with a release liner on the surface (adhesive surface) of the adhesive layer before use. When the above-mentioned adhesive sheet is a double-sided adhesive sheet, each of the two-sided adhesive surfaces in the above-mentioned adhesive sheet can be protected by two pieces of release liners, or one double-sided piece can be used as the release surface. The release liner is rolled into a roll for protection. The release liner is used as a protective material for the adhesive layer and is peeled off when it is attached to the adherend. Furthermore, it is not necessary to provide a release liner.

As the above-mentioned release liner, conventional release paper, etc. can be used without particular limitation. Examples thereof include: a base material having a release treatment layer, a low-adhesion base material containing a fluoropolymer, or a low-adhesion base material containing a non-polar polymer. Adhesive substrates, etc. Examples of the base material having a release treatment layer include plastic film or paper surface-treated with release treatment agents such as silicone-based, long-chain alkyl-based, fluorine-based, and molybdenum sulfide. Examples of the fluorine-based polymer in the low-adhesion base material containing a fluoropolymer include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, and tetrafluoroethylene-hexafluoroethylene. Fluoropropylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer, etc. Examples of the nonpolar polymer include olefin resins (for example, polyethylene, polypropylene, etc.). Furthermore, the release liner can be formed by a known or conventional method. In addition, the thickness of the release liner is not particularly limited.

The above-mentioned adhesive sheet can be used for known or customary purposes of bonding the adherend. Among them, the above-mentioned adhesive sheet is preferably used for adhering the adhesive layer to the insulating layer. In addition, the above-mentioned adhesive sheet is preferably used for attaching battery components, and more preferably is used for attaching all-solid-state battery components from the viewpoint of having a small total outgassing amount and excellent conductivity. Specific examples of battery member attachment applications include fixation of circuit components in batteries, or electrode applications in which the metal base material functions as an electrode.

As an embodiment of the circuit component fixing application and the electrode application, for example, the adhesive layer is bonded to an insulating substrate such as a polyimide film and used, and the metal base material functions as an electrode. . The above-mentioned electrode may be a positive electrode or a negative electrode. In addition, the above-mentioned metal base material may have an active material adhered thereto. For example, as shown in Figure 2, the adhesive sheet 1 can be bonded to the insulating substrate 4 (Figure 2(a)), and the incisions L can be continuously formed by cutting the adhesive layer 3 and the metal substrate 2 to form a direction. The pattern 21 including the adhesive pattern and the metal pattern has the same shape when projected in the thickness direction (Fig. 2(b)). Then, the laminate 22 of the adhesive layer and the metal base material other than the pattern 21 is peeled off from the insulating substrate 4. (Figure 2(c)). In addition, the adhesive force of the adhesive layer is improved by heating, so the adhesive pattern can be subsequently heated to improve the adhesive force of the adhesive pattern to the insulating substrate. [Example]

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited in any way by these examples.

Example 1 (Preparation of polymer A1) Add 60 parts by mass of 2-ethylhexyl acrylate (2EHA) and 15 parts by mass of N-vinyl-2-pyrrolidone (NVP) to a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a condenser. parts, 10 parts by mass of methyl methacrylate (MMA), 15 parts by mass of 2-hydroxyethyl acrylate (HEA), and 200 parts by mass of ethyl acetate as a polymerization solvent, and stirred for 2 hours at 60°C in a nitrogen atmosphere. Then, 0.2 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator was added, and the reaction was carried out at 60° C. for 6 hours to obtain a solution of polymer A1. The Mw of this polymer A1 is 1.1 million, and the Tg based on the Fox formula is -36°C.

(Preparation of polymer B1) 100 parts by mass of toluene, 40 parts by mass of methyl methacrylate (MMA), 20 parts by mass of butyl methacrylate (BMA), 20 parts by mass of 2-ethylhexyl methacrylate (2-EHMA), and functional groups 8.7 parts by mass of methacrylate monomer containing polyorganosiloxane skeleton (trade name "X-22-174ASX", manufactured by Shin-Etsu Chemical Industry Co., Ltd.) with an equivalent weight of 900 g/mol and a functional group equivalent of 4600 g /mol of 11.3 parts by mass of methacrylate monomer containing polyorganosiloxane skeleton (trade name "KF-2012", manufactured by Shin-Etsu Chemical Industry Co., Ltd.), and methyl thioglycolate as a chain transfer agent 0.51 parts by mass was put into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, a condenser, and a dropping funnel. Next, after stirring for 1 hour at 70°C in a nitrogen atmosphere, 0.2 parts by mass of AIBN as a thermal polymerization initiator was added, and after reacting at 70°C for 2 hours, 0.1 part by mass of AIBN as a thermal polymerization initiator was added. Then, the reaction was carried out at 80° C. for 5 hours to obtain a solution of polymer B1. The obtained polymer B1 had an Mw of 20,000. In addition, the functional group equivalent (arithmetic mean) of the polyorganosiloxane skeleton methacrylate monomer is 2990 g/mol.

In addition, Mw of polymer A1 and polymer B1 was measured using GPC apparatus "HLC-8220GPC" (manufactured by Tosoh Corporation) and calculated. GPC conditions are described below. ＜GPC conditions＞ Sample concentration: 0.2 wt% (tetrahydrofuran (THF) solution) Sample injection volume: 10 μl Eluent: THF Flow rate: 0.6 ml/min Measuring temperature: 40℃ Column: sample column; TSK guardcolumn SuperHZ-H (1 piece) + TSKgel SuperHZM-H (2 pieces) Reference column; TSKgel SuperH-RC (1 piece) Detector: Differential Refractometer (RI)

(Production of adhesive sheets) To the solution of the above polymer A1, 2.5 parts by mass of polymer B1 and 2.5 parts by mass of an isocyanate cross-linking agent (trade name "Takenate D-110N", trimethylol) were added per 100 parts by mass of polymer A1. Propane xylylene diisocyanate, manufactured by Mitsui Chemicals Co., Ltd.) and 1.0 parts by mass of a phenolic antioxidant (trade name "Irganox 1010", manufactured by BASF Japan Co., Ltd.) were uniformly mixed to prepare an adhesive composition. The above-mentioned adhesive composition was directly coated on an electrolytic copper foil with a thickness of 18 μm as the base material (trade name "CF-T8G-UN-18", manufactured by Futian Metal Foil Industry Co., Ltd.) and heated at 100°C. It was dried for 2 minutes, thereby forming an adhesive layer with a thickness of 9 μm. A release liner (trade name "MRF38", manufactured by Mitsubishi Chemical Co., Ltd.) is bonded to the surface (adhesive surface) of the adhesive layer. One side of the polyester film has a release layer obtained by using a silicone-based release treatment agent. Peel-off layer of liner, thickness 38 μm). In this way, an adhesive sheet with a release liner is obtained.

Examples 2-3 In the preparation of the adhesive composition, the compounding amount of the phenolic antioxidant was changed as shown in Table 1. Otherwise, the same operation as in Example 1 was performed to prepare an adhesive sheet.

Example 4 In the preparation of the adhesive composition, a phenolic antioxidant (trade name "Irganox 565") was used instead of a phenol antioxidant (trade name "Irganox 1010"). The operation was carried out in the same manner as in Example 2 to prepare an adhesive sheet.

Example 5 An adhesive sheet was produced in the same manner as in Example 2 except that aluminum foil (soft aluminum foil, JISH4160A1N30H-0 adapter, manufactured by UACJ Co., Ltd., thickness 50 μm) was used instead of the electrolytic copper foil.

Example 6 The same operation as in Example 2 was performed except that SUS (Steel Use Stainless, Japanese stainless steel standard) foil (trade name "SUS304 CSP-H", manufactured by Toyo Sei Foil Co., Ltd., thickness 40 μm) was used instead of the electrolytic copper foil. Make an adhesive sheet.

Comparative examples 1 to 3 In the preparation of the adhesive composition, the compounding amount of the phenolic antioxidant was changed as shown in Table 2. Otherwise, the same operation as in Example 1 was performed to prepare an adhesive sheet.

Comparative example 4 In the preparation of the adhesive composition, no phenolic antioxidant was blended. Otherwise, the same operation as in Example 1 was performed to prepare an adhesive sheet.

Comparative example 5 In the preparation of the adhesive composition, a phosphorus-based antioxidant (trade name "Irgafos 168") was used instead of a phenol-based antioxidant (trade name "Irganox1010"). Otherwise, the same operation was performed as in Example 2 to prepare an adhesive sheet. .

Comparative example 6 Use PET (polyethylene terephthalate, polyethylene terephthalate) film (trade name "Toray polyester film "Lumirror (registered trademark)" #25 S10", manufactured by Toray Co., Ltd., thickness 25 μm) instead of electrolysis Except for copper foil, the same operation was performed as in Example 2 to produce an adhesive sheet.

＜Evaluation＞ The adhesive sheets obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in the table.

(1) Total gas release amount Cut the adhesive sheet into 5 cm ² , peel off the release liner to obtain a test piece, and seal it in a headspace bottle. Thereafter, the sample was heated at 200°C for 60 minutes using a headspace sampler (HSS), and 1 mL of the heated gas phase was injected into the gas chromatograph (GC). Secondly, calculate the total gas release amount detected. The analysis equipment and measurement conditions used are as follows. <Analysis device> HSS: Agilent Technologies, G1888 GC: Agilent Technologies, 6890N <Measurement conditions> (HSS conditions) Heating temperature: 200°C Heating time: 60 min Sample loop temperature: 160°C Transfer line temperature: 200°C Pressurization time : 0.20 min Loop filling time: 0.20 min Loop equilibration time: 0.05 min Injection time: 0.50 min (GC conditions) Column: HP-1 (0.250 mm ×30 m, df＝1.0 μm) Column temperature: 40℃(3 min)→10℃/min→120℃→20℃/min→300℃(10 min) Column flow: 1 mL/min (He) Column pressure: constant flow mode (81 kPa) Inlet temperature: 250°C Injection volume: 1 mL Injection method: split (20:1) Detector: FID (flame ionization detector, flame ionization detector) Detector temperature: 250℃

(2)180° peel adhesion test Cut the adhesive sheet into 25 mm wide and use it as a test piece. Prepare the SUS board (304BA board) cleaned with toluene. Secondly, peel off the release liner of the adhesive sheet, and make the 2 kg roller reciprocate on the SUS board to adhere to the adhesive surface of the adhesive sheet. Next, in each of the Examples and Comparative Examples, adhesive sheets placed under the following two conditions were produced. (i) After attaching the adhesive sheet to the SUS board, place it in an environment of 23°C for 30 minutes (initial conditions). (ii) After laminating the adhesive sheet to the SUS board, place it in an environment of 80°C for 5 minutes, and then place it in an environment of 23°C for 30 minutes (conditions after heating at 80°C). Secondly, for the adhesive sheet produced under the conditions (i) and (ii), peel the other end of the adhesive sheet in the peeling direction of 180° at a speed of 300 mm/min, and measure the effect on the SUS board at this time. Adhesion (resistance) (unit: N/25 mm).

(3) Surface resistance value: For the base material surface of the adhesive sheet, in a gas atmosphere with a temperature of 23°C and 50% RH, based on JIS K6911, using a URS probe, under the conditions of an applied voltage of 10 V and an applied time of 10 seconds. , measure the initial surface resistance value [Ω/cm ² ]. As a resistivity meter, a brand name "Hiresta UP MCP-HT450 type" (manufactured by Mitsubishi Chemical Co., Ltd.) was used.

[Table 1] (Table 1) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 base material electrolytic copper foil electrolytic copper foil electrolytic copper foil electrolytic copper foil aluminum foil SUS foil Antioxidants Irganox 1010 1.0 0.5 0.4 - 0.5 0.5 Irganox 565 - - - 0.5 - - Irgafos 168 - - - - - - Total gas release [ppm] 860 12000 15000 15000 12000 12000 180° peel adhesion test [N/25 mm] initial adhesion 0.10 0.10 0.10 0.10 0.20 0.20 Adhesion after heating at 80℃ twenty four twenty four twenty four twenty four 26 26 Surface resistance value [Ω/cm ² ] ^{10-8 ～ 10-4 _ 10-8 ～ 10-4 _ 10-8 ～ 10-4 _ 10-8 ～ 10-4 _ 10-8 ～ 10-4 _ 10-8 ～ 10-4 _}

[Table 2] (Table 2) Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 base material electrolytic copper foil electrolytic copper foil electrolytic copper foil electrolytic copper foil electrolytic copper foil PET Antioxidants Irganox 1010 0.3 0.2 0.1 - - 0.5 Irganox 565 - - - - - - Irgafos 168 - - - - 0.5 - Total gas release [ppm] 17000 16000 17000 18000 19000 12000 180° peel adhesion test [N/25 mm] initial adhesion 0.10 0.10 0.10 0.10 0.10 0.07 Adhesion after heating at 80℃ twenty four twenty four twenty four twenty four twenty four twenty two Surface resistance value [Ω/cm ² ] 10 ^-8 ~ 10 ^-4 10 ^-8 ~ 10 ^-4 10 ^-8 ~ 10 ^-4 10 ^{- 8} ~ 10 ^{-4 10-8 ～ 10-4 _} >10 ¹¹

As shown in the table, the adhesive sheet of the Example has low initial adhesive force and high adhesive force after heating, so it is judged that it has excellent secondary processability and the adhesive force increases with time. In addition, the surface resistance value is low and the conductivity is excellent. Furthermore, although the same adhesive layer was used in Examples 2, 5, and 6, it is speculated that due to the different types or thicknesses of the metal substrates, the peeling adhesive force is affected by the difference in plasticity and strength of the metal substrates. difference. In addition, the total gas release amount of the adhesive sheets of the examples is compared with the case where the content of the phenolic antioxidant is smaller (Comparative Examples 1 to 3), the case where the phenolic antioxidant is not included (Comparative Example 4), and the case where phosphorus is used. The number of antioxidants (Comparative Example 5) was reduced. In addition, when a plastic film is used as the base material (Comparative Example 6), the surface resistance value is low and the conductivity is poor.

In the following, modification examples of the present invention will be described. [Supplementary Note 1] An adhesive sheet comprising: a metal base material, and an adhesive layer provided on at least one side of the metal base material, and The above-mentioned adhesive layer contains 0.1 to 20 parts by mass of polymer (B) and more than 0.4 parts by mass of phenolic antioxidant relative to 100 parts by mass of polymer (A) whose glass transition temperature is less than 0°C. The polymer (B) ) contains a monomer (B1) with a polyorganosiloxane skeleton and a monomer (B2) with a homopolymer glass transition temperature of 40°C or above as monomer units, and the functional group equivalent of the monomer (B1) (arithmetic average) is 1000 g/mol or more and less than 15000 g/mol, and the weight average molecular weight of the polymer (B) is 10000 or more but less than 100000. [Supplement 2] The adhesive sheet according to Appendix 1, wherein the phenolic antioxidant contains a compound having two or more phenolic skeletons. [Appendix 3] For adhesive sheets as described in Appendix 1 or 2, the total gas release amount is 15,500 ppm or less. [Appendix 4] The adhesive sheet described in any one of Appendices 1 to 3 is used for attaching battery components. [Appendix 5] The adhesive sheet described in Appendix 4 is used for attaching all-solid-state battery components. [Appendix 6] An electrode for an all-solid-state battery, comprising: an insulating substrate, an adhesive sheet as described in Appendix 5 in which the adhesive layer is bonded to the insulating substrate, and a metal adhered to the adhesive sheet The active material of the base material.

1: Adhesive sheet 2: Metal substrate 3: Adhesive layer 4: Insulating base material 21:Pattern 22: Laminated body L: incision

FIG. 1 is a schematic cross-sectional view of an adhesive sheet according to one embodiment of the present invention. Figures 2 (a) to (c) are schematic cross-sectional views showing a method of producing electrodes using the adhesive sheet shown in Figure 1.

1: Adhesive sheet

2: Metal substrate

3: Adhesive layer

Claims (6)

An adhesive sheet, which is provided with: a metal base material, and an adhesive layer provided on at least one side of the metal base material, and The above-mentioned adhesive layer contains 0.1 to 20 parts by mass of polymer (B) and more than 0.4 parts by mass of phenolic antioxidant relative to 100 parts by mass of polymer (A) whose glass transition temperature is less than 0°C. The polymer (B) ) contains a monomer (B1) with a polyorganosiloxane skeleton and a monomer (B2) with a homopolymer glass transition temperature of 40°C or above as monomer units, and the functional group equivalent of the monomer (B1) (arithmetic average) is 1000 g/mol or more and less than 15000 g/mol, and the weight average molecular weight of the polymer (B) is 10000 or more but less than 100000. The adhesive sheet of claim 1, wherein the phenolic antioxidant contains a compound having two or more phenolic skeletons. For example, if the adhesive sheet of claim 1 or 2 is used, the total gas release amount is less than 15,500 ppm. For example, the adhesive sheet of claim 1 or 2 is used for attaching battery components. For example, the adhesive sheet of claim 4 is used for attaching all-solid-state battery components. An all-solid-state battery electrode, which is provided with: an insulating substrate, an adhesive sheet as claimed in claim 5 in which the above-mentioned adhesive layer is bonded to the above-mentioned insulating substrate, and an active material attached to the metal base material in the above-mentioned adhesive sheet. .