Adhesive sheet

Abstract

To provide an adhesive sheet having excellent long-term durability.SOLUTION: An adhesive sheet according to the present invention has a substrate, and an adhesive layer laminated on at least one surface of the substrate, the adhesive layer containing a butyl rubber as an organic component. After heated for 7 weeks at 100°C, the butyl rubber has a retention rate of molecular weight of 20% or more.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] This invention relates to an adhesive sheet. More specifically, this invention relates to an adhesive sheet used for applying a breathable waterproof sheet to a target object. [Background technology]

[0002] Conventionally, in order to protect interior walls of houses from rainwater and other elements, it is known to attach a breathable waterproof sheet made of nonwoven fabric or the like to the interior walls or the like (for example, Patent Document 1 below).

[0003] Patent Document 1 below describes an adhesive sheet comprising a first adhesive layer to be attached to the object to be constructed and a second adhesive layer to be attached to a waterproof and breathable sheet. Furthermore, Patent Document 1 below describes an adhesive sheet in which the first adhesive layer contains a first rubber component comprising 40-93% by mass of butyl rubber and 7-60% by mass of polyisobutylene, and further, the kinematic viscosity of the first adhesive layer at 40°C is 100-9000 mm². 2 It is stated that the first softening agent, which is / s, is included in a blending ratio of 82 to 128 parts by mass per 100 parts by mass of the first rubber component. Furthermore, it is stated that by configuring the adhesive sheet as described above, excellent adhesion can be achieved over a wide temperature range (-10°C to 60°C) when the breathable waterproof sheet is applied to the installation site. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2015-54888 [Overview of the project] [Problems that the invention aims to solve]

[0005] Meanwhile, when the application target of the pressure-sensitive adhesive sheet is an object having a long service life such as an interior wall of a house, in addition to being required to exhibit excellent adhesiveness in a wide temperature range, the pressure-sensitive adhesive sheet is also required to have the property of being hardly peeled off from the application target over a long period of several tens of years or more after being applied to the application target (hereinafter, also referred to as long-term durability).

[0006] However, it is difficult to say that sufficient studies have been conducted to make pressure-sensitive adhesive sheets excellent in long-term durability.

[0007] Therefore, an object of the present invention is to provide a pressure-sensitive adhesive sheet excellent in long-term durability. [Means for Solving the Problem]

[0008] As a result of intensive studies by the present inventor, it has been found that in a pressure-sensitive adhesive sheet having a substrate and a pressure-sensitive adhesive layer laminated on at least one surface of the substrate, when the pressure-sensitive adhesive layer contains butyl rubber as an organic component and the molecular weight retention rate of the butyl rubber after heating at 100°C for 7 weeks is 20% or more, the pressure-sensitive adhesive sheet becomes excellent in long-term durability. Thus, the present invention has been completed.

[0009] That is, the pressure-sensitive adhesive sheet according to the present invention is a substrate,[|END]] and a pressure-sensitive adhesive layer laminated on at least one surface of the substrate, wherein the pressure-sensitive adhesive layer contains butyl rubber as an organic component,[|END]] and the molecular weight retention rate of the butyl rubber after heating at 100°C for 7 weeks is 20% or more. [Effect of the Invention]

[0010] According to the present invention, a pressure-sensitive adhesive sheet excellent in long-term durability can be provided. [Brief Description of Drawings]

[0011] [Figure 1A] A cross-sectional view showing the structure of an adhesive sheet according to one embodiment of the present invention. [Figure 1B] A cross-sectional view showing a configuration in which a sealing layer is provided in an adhesive sheet according to one embodiment of the present invention. [Figure 2] A diagram illustrating the auto-oxidation reaction. [Figure 3] A cross-sectional view showing the configuration of an adhesive sheet according to another embodiment of the present invention. [Modes for carrying out the invention]

[0012] The adhesive sheet according to the present invention is an adhesive sheet having a base material and an adhesive layer laminated on at least one side of the base material. In the adhesive sheet according to the present invention, the adhesive layer contains butyl rubber (isobutylene-isoprene rubber (IIR)) as an organic component. In the adhesive sheet according to the present invention, the molecular weight retention rate of the butyl rubber after heating at 100°C for 7 weeks is 20% or more.

[0013] Here, "the retention rate of the molecular weight of the butyl rubber after heating at 100°C for 7 weeks is 20% or more" means that the peak top value of the molecular weight (in the range of 250,000 to 800,000) attributed to the butyl rubber, as determined by GPC (gel permeation chromatography) before heating at 100°C, is M P0 The peak top value of the molecular weight (in the range of 250,000 to 800,000) attributed to the butyl rubber, determined by GPC after heating at 100°C for 7 weeks, is M. P1 When that happens, M P1 to M P0 The value obtained by dividing by and then multiplying by 100 (M P1 / M P0 This means that the calculated value (calculated by multiplying by 100) is 20 or greater. The molecular weight attributed to the butyl rubber refers to the mass-average molecular weight.

[0014] The molecular weight (mass-average molecular weight) assigned to the butyl rubber by the GPC can be determined as a converted value for standard polystyrene. More specifically, it can be determined by using a TOSOH HLC-8420GPC to obtain a sample as follows, and then measuring it under the following conditions. [Method of obtaining specimens] (1) Samples taken from the adhesive layer containing butyl rubber (samples taken from the adhesive layer before heating at 100°C, and samples taken from the adhesive layer after heating at 100°C for 7 weeks) are prepared in a 1.0 g / L THF solution and left to stand overnight. (2) The THF solution, which has been left to stand overnight, is filtered through a membrane filter with a pore size of 0.45 μm, and the resulting filtrate is used as the sample. [GPC measurement conditions] ·column This setup consists of TSKgel SuperHZM-H, TSKgel SuperHZ4000, TSKgel SuperHZ3000, and TSKgel SuperHZ200 (all manufactured by TOSOH) connected in series using a ferrule connection. • Column size Each is 6.0mm I.D. × 150mm • Eluent THF ·Flow rate 0.6 mL / min • Column temperature 40℃ Detector RI ·Injection amount 20 μL

[0015] Since the butyl rubber is obtained by addition polymerization of isobutylene, one raw material monomer, and isoprene, another raw material monomer, the main chain of the butyl rubber contains carbon-carbon double bonds derived from the isoprene. The deterioration of the butyl rubber occurs when the main chain is cleaved at the α-position carbon adjacent to the carbon-carbon double bond due to oxidation reactions, resulting in the butyl rubber becoming low molecular weight or its molecular weight falling below 250,000, or when the main chains are bonded together at the α-position carbon adjacent to the carbon-carbon double bond due to oxidation reactions, resulting in polymerization (the molecular weight of the butyl rubber exceeding 800,000). Furthermore, if the adhesive layer contains polymerized butyl rubber, the adhesive layer becomes hard, and if the adhesive layer contains low-molecular-weight butyl rubber, the adhesive layer becomes soft. As described above, when the adhesive layer hardens or softens, it becomes difficult for the adhesive layer to exhibit sufficient adhesion to the application surface (for example, the interior walls of a house).

[0016] Here, heating the adhesive sheet at 100°C for 7 weeks is equivalent to an "accelerated degradation test," which assumes that the degradation of the butyl rubber in the adhesive layer, which would normally occur over a long period, will progress in a short period of time by exposing the adhesive sheet to harsh conditions. Therefore, after heating at 100°C for 7 weeks, the higher the retention rate of the molecular weight of the butyl rubber in the adhesive layer, that is, the lower the proportion of degraded butyl rubber in the adhesive layer, the more the adhesive layer will exhibit sufficient adhesion to the object to be applied for a long period of time. In other words, the adhesive layer will have excellent long-term durability, and consequently, the adhesive sheet equipped with the adhesive layer will also have excellent long-term durability. As explained above, the adhesive sheet according to the present invention maintains a relatively high molecular weight retention rate of 20% or more of the butyl rubber after being heated at 100°C for 7 weeks. Therefore, the adhesive layer exhibits sufficient adhesion to the object to be applied over a long period of time. In other words, the adhesive sheet according to the present invention, which has the adhesive layer described above, has excellent long-term durability. In the following, the molecular weight retention rate of the butyl rubber after heating at 100°C for 7 weeks will also be referred to as the molecular weight retention rate of the butyl rubber after the accelerated degradation test.

[0017] The molecular weight retention rate of the butyl rubber after the accelerated degradation test is preferably 50% or more, more preferably 60% or more, even more preferably 70% or more, even more preferably 80% or more, and particularly preferably 90% or more.

[0018] In the following, with reference to Figure 1A, we will first describe an adhesive sheet according to one embodiment of the present invention, using a single-sided adhesive sheet in which an adhesive layer is laminated on one side of a substrate as an example.

[0019] As shown in Figure 1A, the adhesive sheet 10 according to one embodiment of the present invention comprises a base material 1 and an adhesive layer 2 laminated on one side of the base material 1. In this type of single-sided adhesive sheet, the adhesive layer 2 is attached to the breathable waterproof sheet.

[0020] As described above, the adhesive layer 2 contains butyl rubber as an organic component.

[0021] As explained earlier, butyl rubber is a copolymer (isobutylene-isoprene) obtained by addition polymerization of isobutylene (isobutene) and isoprene. More specifically, the butyl rubber is a copolymer of isobutylene and a small amount of isoprene. Examples of butyl rubber include synthetic butyl rubber and recycled butyl rubber. The adhesive layer 2 preferably contains synthetic butyl rubber as its main component. The adhesive layer 2 preferably contains 70% by mass or more of synthetic butyl rubber, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 100% by mass, based on the total amount of butyl rubber. In other words, it is particularly preferable that all of the butyl rubber contained in the adhesive layer 2 is synthetic butyl rubber. The recycled butyl rubber is obtained by recycling rubber products (such as tires and tubes) made from butyl rubber, and in the recycling process, oils such as pine oil and mineral oil are used. Therefore, the recycled butyl rubber retains the oil used in the recycling process. In this case, if the adhesive layer 2 contains recycled butyl rubber as the butyl rubber, when a breathable waterproof sheet is attached to the adhesive layer 2, the oil contained in the recycled butyl rubber will migrate to the breathable waterproof sheet. Furthermore, if the breathable waterproof sheet is made of a fibrous sheet (especially if it is made of a high-density polyethylene nonwoven fabric), the breathable waterproof sheet will swell due to the oil that has migrated from the adhesive layer 2. Thus, when the breathable waterproof sheet swells, it becomes impossible to ensure sufficient adhesion of the adhesive layer 2 to the breathable waterproof sheet, which is undesirable. However, as described above, since the adhesive layer 2 contains 70% by mass or more of synthetic butyl rubber when based on the total amount of butyl rubber, the amount of oil derived from recycled rubber in the adhesive layer 2 can be kept relatively low. Therefore, even if the breathable waterproof sheet is made of fiber sheets, swelling of the breathable waterproof sheet can be suppressed.

[0022] The mass-average molecular weight of the butyl rubber is preferably 30,000 or more and 1,500,000 or less. The mass-average molecular weight of the butyl rubber is more preferably 200,000 or more, and even more preferably 300,000 or more. Furthermore, the mass-average molecular weight of the butyl rubber is more preferably 800,000 or less, and even more preferably 700,000 or less.

[0023] The mass-average molecular weight of the butyl rubber contained in the adhesive layer 2 can be determined from GPC (gel permeation chromatography) measurement as a converted value to that of standard polystyrene. More specifically, the mass-average molecular weight of the butyl rubber contained in the adhesive layer 2 can be measured using a TOSOH HLC-8420GPC in the same manner as described above.

[0024] The adhesive layer 2 may contain rubber components other than butyl rubber as organic components. Other rubber components besides butyl rubber include other rubbers and thermoplastic elastomers.

[0025] Other types of rubber besides butyl rubber include polyisobutylene rubber, acrylic rubber, silicone rubber, urethane rubber, vinyl alkyl ether rubber, polyvinyl alcohol rubber, polyvinylpyrrolidone rubber, polyacrylamide rubber, cellulose rubber, natural rubber, butadiene rubber, chloroprene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, isoprene rubber, and ethylene-propylene rubber. Examples of thermoplastic elastomers include styrene-based thermoplastic elastomers and acrylic-based thermoplastic elastomers. Examples of the styrene-based thermoplastic elastomers include styrene-ethylene-butadiene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), styrene-isobutylene-styrene block copolymer (SIBS), styrene-butadiene-styrene block copolymer (SBS), and styrene-ethylene-propylene-styrene block copolymer (SEPS). Examples of the acrylic thermoplastic elastomer include acrylic rubber mainly composed of acrylic acid ester, and examples of the acrylic rubber include copolymers of acrylic acid ester and 2-chloroethyl vinyl ether, copolymers of acrylic acid ester and acrylonitrile, and copolymers of acrylic acid ester and acrylic acid. Among the above, the adhesive layer 2 preferably contains the thermoplastic elastomer, and more preferably contains a styrene-based thermoplastic elastomer. Furthermore, it is preferable that the adhesive layer 2 contains at least one of styrene-isoprene-styrene block copolymer (SIS) and styrene-isobutylene-styrene block copolymer (SIBS) among styrene-based thermoplastic elastomers.

[0026] The weight-average molecular weight of the thermoplastic elastomer is preferably between 20,000 and 1,500,000. The above mass-average molecular weight can be determined from GPC (gel permeation chromatography) measurements as a conversion value to standard polystyrene. The mass-average molecular weight of the thermoplastic elastomer can be measured in the same manner as the measurement of the mass-average molecular weight of the butyl rubber described above.

[0027] The adhesive layer 2 preferably contains 1 part by mass or more of the thermoplastic elastomer with respect to 100 parts by mass of the total amount of the butyl rubber and the thermoplastic elastomer. Furthermore, the adhesive layer 2 more preferably contains 3 parts by mass or more, more preferably 5 parts by mass or more, more preferably 7 parts by mass or more, and more preferably 9 parts by mass or more of the thermoplastic elastomer with respect to 100 parts by mass of the total amount of the butyl rubber and the thermoplastic elastomer. The upper limit for the amount of thermoplastic elastomer relative to the total amount of butyl rubber and thermoplastic elastomer (100 parts by mass) is usually 30 parts by mass. The aforementioned upper limit may be 20 parts by mass. Because the adhesive layer 2 contains the thermoplastic elastomer within the above numerical range, the adhesive layer 2 can exhibit even greater adhesion over a wide temperature range from low temperatures (e.g., -10°C) to high temperatures (e.g., 60°C). In other words, the adhesive layer 2 can exhibit even greater adhesion to the adherend.

[0028] When the adhesive layer 2 contains a styrene-based thermoplastic elastomer as the thermoplastic elastomer, the styrene content (styrene amount) in the styrene-based thermoplastic elastomer is preferably 10% by mass or more, more preferably 12% by mass or more, and even more preferably 20% by mass or more. Furthermore, the styrene content in the styrene-based thermoplastic elastomer is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less. Furthermore, if the adhesive layer 2 contains a styrene-based thermoplastic elastomer as the thermoplastic elastomer, the diblock rate of the styrene-based thermoplastic elastomer is preferably 10% or more, more preferably 25% or more, and even more preferably 50% or more. Furthermore, the diblock rate of the styrene-based thermoplastic elastomer is preferably 70% or less. Because the diblock ratio of the styrene-based thermoplastic elastomer is within the above numerical range, the adhesive sheet 10 can exhibit even greater adhesiveness over a wide temperature range from low temperatures (e.g., -10°C) to high temperatures (e.g., 60°C).

[0029] The Zibloc rate (%) can be calculated using the following formula. Diblock ratio (%) = parts by mass of diblock copolymer / (parts by mass of diblock copolymer + parts by mass of triblock copolymer) × 100

[0030] Specifically, the diblock ratio can be calculated by measuring the molecular weight of the styrene-based thermoplastic elastomer using gel permeation chromatography (GPC), and then determining the area ratio of the peaks attributed to diblock copolymers and the peaks attributed to triblock copolymers in the resulting chart. The GPC method can be performed in the same manner as described for the measurement of the mass-average molecular weight of butyl rubber.

[0031] One method for adjusting the diblock ratio in the aforementioned styrene-based thermoplastic elastomer is to change the ratio of polymerization initiator and coupling agent used during polymerization (amount of coupling agent / amount of polymerization initiator).

[0032] The adhesive layer 2 preferably contains 8% by mass or more of rubber components, and more preferably contains 12% by mass or more. Furthermore, the adhesive layer 2 preferably contains 50% by mass or less of the rubber component, and more preferably contains 45% by mass or less. The term "rubber component" refers collectively to butyl rubber, rubbers other than butyl rubber, and thermoplastic elastomers.

[0033] The adhesive layer 2 may contain organic components other than rubber, such as softeners, tackifiers, and anti-aging agents. In order to further suppress the deterioration of the butyl rubber in the adhesive layer 2, it is preferable that the adhesive layer 2 contains an anti-aging agent among the various organic components other than the rubber components mentioned above. Furthermore, in order to provide good adhesion with the adhesive layer 2, it is preferable that the adhesive layer 2 contains a tackifier among the various organic components other than the rubber components mentioned above.

[0034] Examples of the aforementioned softening agents include paraffins, waxes, naphthenes, aromas, asphalts, drying oils (e.g., linseed oil), animal and vegetable oils, petroleum oils (e.g., process oils), polybutene, polyisobutylene, ethylene-α-olefin co-oligomers, low molecular weight polyethylene glycol, phthalates, phosphate esters, stearic acid or its esters, alkyl sulfonic acid esters, and the like. The aforementioned softening agents may be used alone or in combination of two or more types. The adhesive layer 2 preferably contains at least one of these: polyisobutylene and ethylene-α-olefin co-oligomer.

[0035] The kinematic viscosity of the softener at 40°C is 700 mm 2 / s or more, more preferably 900 mm 2 / s or more. Further, the kinematic viscosity of the softener at 40°C is 100000 mm 2 / s or less, more preferably 50000 mm 2 / s or less.

[0036] The kinematic viscosity is measured in accordance with JIS K 2283 (2000). Specifically, the kinematic viscosity is measured using a glass capillary viscometer apparatus. In the case where a plurality of softeners having different kinematic viscosities are used, the kinematic viscosity is determined as the kinematic viscosity of a mixture of the plurality of softeners.

[0037] The pressure-sensitive adhesive layer 2 preferably contains 30 parts by mass or more of the softener relative to 100 parts by mass of the rubber component, more preferably 50 parts by mass or more, and still more preferably 120 parts by mass or more. Further, the pressure-sensitive adhesive layer 2 preferably contains 500 parts by mass or less of the softener relative to 100 parts by mass of the rubber component, more preferably 400 parts by mass or less, and still more preferably 300 parts by mass or less.

[0038] Examples of the tackifier include rosin-based resins, terpene-based resins, styrene-based resins, petroleum-based resins, phenolic resins, and hydrogenated resins obtained by hydrogenating these resins. These tackifiers may be used alone, or two or more of them may be used in combination.

[0039] Examples of the rosin-based resin include rosin resins, rosin ester resins, and rosin phenolic resins. The terpene resin can be any compound having a structural unit derived from isoprene, such as terpene resins, aromatically modified terpene resins, and terpene phenol resins. Examples of styrene-based resins include resins obtained by copolymerizing styrene-based monomers such as α-methylstyrene or β-methylstyrene with aliphatic monomers. Examples of petroleum-based resins include C5 hydrocarbon resins obtained by copolymerizing C5 fractions such as pentene, isoprene, piperine, and 1,3-pentadiene, which are produced by the thermal decomposition of petroleum naphtha; and C9 hydrocarbon resins obtained by copolymerizing C9 fractions such as indene and vinyltoluene, which are produced by the thermal decomposition of petroleum naphtha. Examples of phenolic resins include alkylphenolic resins, xylyleneformaldehyde resins, resols, and novolacs.

[0040] The adhesive layer 2 preferably contains a petroleum-based resin among the tackifiers mentioned above, and more preferably contains a C5-based hydrocarbon resin as the petroleum-based resin. The adhesive layer 2 preferably contains 5 parts by mass or more, and more preferably 10 parts by mass or more, of the tackifier per 100 parts by mass of the rubber component. Furthermore, the adhesive layer 2 preferably contains 200 parts by mass or less of the tackifier per 100 parts by mass of the rubber component, more preferably 150 parts by mass or less, and even more preferably 70 parts by mass or less. Furthermore, in the adhesive layer 2, the ratio of the butyl rubber content to the tackifier content (butyl rubber content / tackifier content) is preferably 2.2 or higher, more preferably 3.0 or higher, and even more preferably 5.0 or higher. Furthermore, in the adhesive layer 2, the ratio of the butyl rubber content to the tackifier content is preferably 15.0 or less, more preferably 10.0 or less, and even more preferably 8.0 or less.

[0041] Examples of the aforementioned antioxidants include phenolic antioxidants, amine-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants.

[0042] Examples of the phenolic antioxidants include bisphenolic antioxidants and hindered phenolic antioxidants. Examples of the bisphenol-based antioxidants include 2,2'-methylenebis(4-methyl-6-tert-butylphenol), represented by formula (1) below, and 4,4'-thiobis(3-methyl-6-tert-butylphenol), represented by formula (2) below. Examples of commercially available bisphenol-based antioxidants represented by the following formula (1) include "Nocrac NS-6" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Furthermore, commercially available bisphenol-based antioxidants represented by the following formula (2) include "Nocrac 300" manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0043] [ka]

[0044] [ka]

[0045] Examples of the hindered phenol-based antioxidants include tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, represented by the following formula (3), and 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, represented by the following formula (4). Commercially available hindered phenol-based antioxidants represented by formula (3) below include "ADEKA Stab AO-60" manufactured by ADEKA Corporation, "SONGNOX® 1010" manufactured by SONGWON Corporation, and "Irganox® 1000" manufactured by BASF Corporation. Furthermore, commercially available hindered phenol-based antioxidants represented by the following formula (4) include "SUMILIZER GA-80" manufactured by Sumitomo Chemical Co., Ltd. and "ADEKA Stab AO-80" manufactured by ADEKA Corporation.

[0046] [ka]

[0047] [ka]

[0048] The phenolic antioxidant is preferably one with a mass-average molecular weight of 350 or more, more preferably 500 or more, more preferably 600 or more, more preferably 700 or more, more preferably 800 or more, more preferably 900 or more, and more preferably 1000 or more. By having the mass-average molecular weight of the phenolic antioxidant within the above numerical range, it is possible to suppress the volatilization of the phenolic antioxidant from the adhesive layer 2. This makes it possible to more effectively suppress the deterioration of the butyl rubber contained in the adhesive layer 2 due to oxidation reactions, etc. (such as the butyl rubber becoming polymerized or depolymerized).

[0049] The amine-based antioxidant is preferably an aromatic secondary amine-based antioxidant. The aforementioned aromatic secondary amine-based antioxidant is a secondary amine in which an aromatic tube is bonded to a nitrogen atom. The aforementioned aromatic secondary amine antioxidant is preferably one with a softening point of 50°C or higher, and more preferably one with a softening point of 80°C or higher. Furthermore, the aromatic secondary amine-based antioxidant is preferably one with a mass-average molecular weight of 300 or more, and more preferably one with a mass-average molecular weight of 350 or more.

[0050] Examples of the aforementioned aromatic secondary amine-based antioxidants include N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine represented by formula (5) below, N,N'-di-naphthyl-p-phenylenediamine represented by formula (6) below, and 4,4'-bis(α,α-dimethylbenzyl)diphenylamine represented by formula (7) below. Examples of commercially available aromatic secondary amine antioxidants represented by the following formula (5) include "Nocrack 6C" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Furthermore, commercially available aromatic secondary amine antioxidants represented by the following formula (6) include "Nocrack White," a product manufactured by Ouchi Shinko Chemical Industry Co., Ltd. Furthermore, commercially available aromatic secondary amine-based antioxidants represented by the following formula (7) include "Nocrack CD," a product manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] Furthermore, amine-based antioxidants generally have the property of being highly colorable to rubber components such as butyl rubber. For example, the aromatic secondary amine-based antioxidant represented by formula (5) above has the property of having high colorability for rubber components such as butyl rubber. In contrast, the aromatic secondary amine antioxidant represented by formula (6) and the aromatic secondary amine antioxidant represented by formula (7) have the property of having low coloring (staining) properties with respect to rubber components such as butyl rubber. In other words, the aromatic secondary amine-based antioxidants represented by formulas (6) and (7) above are amine-based antioxidants characterized by being non-contaminating. Therefore, from the viewpoint of suppressing contamination of rubber components by coloring, it is preferable to use aromatic secondary amine-based antioxidants represented by formulas (6) and (7) above as the amine-based antioxidant.

[0055] Examples of the phosphorus-based antioxidant include tris(2,4-di-tert-butylphenyl)phosphite, represented by the following formula (8). Examples of commercially available phosphorus-based anti-aging agents represented by the formula (8) below include "Irgafos® 168" manufactured by BASF and "SONGNOX® 168" manufactured by SONGWON.

[0056] [ka]

[0057] Examples of the sulfur-based antioxidant include 2-mercaptobenzimidazole, represented by the following formula (9). Examples of commercially available sulfur-based antioxidants represented by the following formula (9) include "Sumilizer(registered trademark) MB" manufactured by Sumika Chemtex Co., Ltd.

[0058] [ka]

[0059] Of the antioxidants described above, the phenolic antioxidant and the amine antioxidant are called primary antioxidants, while the phosphorus antioxidant and the sulfur antioxidant are called secondary antioxidants. Here, the primary antioxidant is an antioxidant that preferentially reacts with the radicals generated from the butyl rubber, or in other words, stabilizes the radicals in a reaction in which the oxidation of the butyl rubber proceeds, initiated by a reaction in which radicals are generated from the butyl rubber (hereinafter referred to as the auto-oxidation reaction). The secondary antioxidant is an antioxidant that suppresses the progress of the auto-oxidation reaction by decomposing the hydroperoxide generated in the auto-oxidation reaction. Here, the aforementioned secondary anti-aging agent is also called a peroxide-decomposing anti-aging agent because it has the property of decomposing hydroperoxides as described above. The auto-oxidation reaction described above is one aspect of the oxidation reaction of the butyl rubber. Furthermore, other embodiments of the oxidation reaction of the butyl rubber include a direct oxidation reaction in which the oxidation of the butyl rubber proceeds because the adhesive layer 2 contains an oxidizing agent.

[0060] Furthermore, the anti-aging agent may be a composite anti-aging agent that possesses both the properties of the primary anti-aging agent and the properties of the secondary anti-aging agent. Examples of the aforementioned complex antioxidants include those containing sulfur in the structure of a compound having a phenol structure, i.e., sulfur-containing phenolic antioxidants. Examples of the sulfur-containing phenolic antioxidant include 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazine-2-ylamino)phenol, represented by the following formula (10). Examples of commercially available sulfur-containing phenolic antioxidants represented by the following formula (10) include BASF's product name "Irganox® 565".

[0061] [ka]

[0062] The adhesive layer 2 preferably contains 2 parts by mass or more of the anti-aging agent per 100 parts by mass of the rubber component, more preferably 3 parts by mass or more, more preferably 4 parts by mass or more, and more preferably 5 parts by mass or more. Furthermore, the adhesive layer 2 preferably contains 15 parts by mass or less, more preferably 12 parts by mass or less, more preferably 10 parts by mass or less, and more preferably 8 parts by mass or less of the anti-aging agent per 100 parts by mass of the rubber component. By keeping the content of the aforementioned antioxidant within the above range, it is possible to suppress the bleeding phenomenon caused by the antioxidant in the adhesive layer 2, and to suppress the deterioration of the butyl rubber due to oxidation. Furthermore, setting the upper limit of the aforementioned anti-aging agent as described above is also advantageous in terms of cost.

[0063] The adhesive layer 2 preferably contains at least one selected from the group consisting of the phenolic antioxidant, the amine antioxidant, the phosphorus antioxidant, and the sulfur antioxidant. Among the various anti-aging agents mentioned above, it is preferable that the adhesive layer 2 contains the phenolic anti-aging agent. In other words, it is preferable that the adhesive layer 2 contains the phenolic antioxidant as the primary antioxidant.

[0064] The adhesive layer 2 preferably contains at least one selected from the first group consisting of the phenolic antioxidant and the amine antioxidant, and at least one selected from the second group consisting of the phosphorus antioxidant and the sulfur antioxidant. In other words, it is preferable that the adhesive layer 2 contains both the primary anti-aging agent and the secondary anti-aging agent. Furthermore, it is preferable that the adhesive layer 2 contains the phenolic antioxidant as the primary antioxidant and the phosphorus-based antioxidant as the secondary antioxidant. Furthermore, it is more preferable that the adhesive layer 2 contains the amine-based antioxidant in addition to the phenol-based antioxidant as a primary antioxidant, and also contains the phosphorus-based antioxidant as a secondary antioxidant. By including at least one of the primary antioxidant and the secondary antioxidant in the adhesive layer 2 in any of the above embodiments, the molecular weight of the butyl rubber after heating at 100°C for 7 weeks can be more effectively maintained at 20% by mass or more. As a result, the adhesive layer 2 becomes highly durable over the long term, and consequently, the adhesive sheet 10 also becomes highly durable over the long term.

[0065] When the adhesive layer 2 contains the phenolic antioxidant as the primary antioxidant and the phosphorus-based antioxidant as the secondary antioxidant, it is preferable that the phenolic antioxidant is present in a larger amount than the phosphorus-based antioxidant. The content of the phenolic antioxidant in the adhesive layer 2 is C F The content of the phosphorus-based anti-aging agent in the adhesive layer 2 is set to C P In that case, C P C F The ratio (C F / C P ) is preferably 1.1 or higher, more preferably 1.5 or higher, and even more preferably 1.8 or higher.

[0066] If the adhesive layer 2 contains the amine-based antioxidant in addition to the phenol-based antioxidant as the primary antioxidant, it is preferable that the phenol-based antioxidant is present in a larger amount than the amine-based antioxidant. The content of the amine-based antioxidant in the adhesive layer 2 is C A In that case, C A C F The ratio (C F / CA ) is preferably 1.1 or higher, more preferably 1.5 or higher, more preferably 2.0 or higher, more preferably 2.5 or higher, more preferably 3.0 or higher, and more preferably 3.5 or higher.

[0067] Next, the auto-oxidation reaction will be explained below with reference to Figure 2. As shown in Figure 2, the auto-oxidation reaction comprises an initiation reaction (see (a) in Figure 2) in which hydrogen is extracted from the main chain of the butyl rubber to obtain a radical derived from the butyl rubber (hereinafter also referred to as the first radical) and a hydrogen radical; a chain and growth reaction (see (b) in Figure 2) in which multiple radicals different from the first radical are generated and multiple products are obtained while regenerating the first radical; and a termination reaction (see (c) in Figure 2) in which the first radical, multiple radicals different from the first radical species, and the hydrogen radical are eliminated to stop the chain and growth reaction. The following describes (a) the initiation reaction, (b) the chain and growth reaction, and (c) the termination reaction. In Figure 2, the hydrogen extracted by the initiation reaction in the butyl rubber is denoted as H, and the portion that constitutes the first radical through the extraction of hydrogen H is denoted as R.

[0068] <(a) Initiation reaction> As explained earlier, the butyl rubber contained in the adhesive layer 2 has a carbon-carbon double bond derived from isoprene in its main chain. In butyl rubber constructed in this manner, among the multiple hydrogen atoms (H) present in the main chain, the hydrogen atom (H) bonded to the α-position carbon (C) adjacent to the carbon-carbon double bond is the most easily abstracted. Therefore, when the adhesive layer 2 containing the butyl rubber is subjected to external energy such as heat or light, the bond between the carbon (C) and hydrogen (H) at the α-position is excited to a higher energy state. As a result, the hydrogen (H) bonded to the α-position carbon (C) is abstracted away from the α-position carbon (C). In other words, a hydrogen (H) is abstracted from the α-position carbon (C), resulting in the formation of a first radical R· and a hydrogen radical H·. Thus, the reaction that produces R· as the first radical and the hydrogen radical H· is the initiation reaction of the auto-oxidation reaction (see equation (1) in Figure 2).

[0069] <(b) Chain reaction / growth> The first radical R· produced by the initiation reaction can readily react with oxygen (O2) in the air. Therefore, when the first radical R· reacts with oxygen (O2), a different peroxyl radical (ROO·) is produced (see equation (2) in Figure 2). Next, the peroxyl radical (ROO·) abstracts a hydrogen atom (H) from a carbon atom (C) at a different α-position than the one mentioned earlier, yielding a hydroperoxide (ROOH) as a product, and generating a first radical R· (see equation (3) in Figure 2). In other words, the first radical R· is regenerated, and the hydroperoxide (ROOH) is obtained as a product. Here, the hydroperoxide (ROOH) is a peroxide, and the bond between RO and OH is easily broken. Therefore, in the hydroperoxide (ROOH), the bond between RO and OH is then broken, generating a radical RO· and a hydroxyl radical (·OH), which are different from the first radical R· (see equation (4) in Figure 2). Next, the radical RO· generated by equation (4) abstracts a hydrogen atom (H) from a carbon atom (C) at a different α-position than the one mentioned earlier, yielding the alcohol (ROH) as a product, and simultaneously generating the first radical R· (see equation (5) in Figure 2). Furthermore, the hydroxyl radical (·OH) generated by equation (4) also extracts hydrogen (H) from a different α-position carbon (C) than the one mentioned earlier, yielding water (H2O) as a product and generating the first radical R· (see equation (6) in Figure 2). In other words, the first radical R· is regenerated, and alcohol (ROH) and water (H2O) are obtained as products. Furthermore, in the chain growth reaction, at least a portion of the radical RO· generated by equation (4) undergoes a main chain cleavage reaction at the R portion, yielding the compound R2CHO having an aldehyde group (CHO), and generating a radical R1· that is different from the first radical R· (see equation (7) in Figure 2). As a result of the reaction shown in equation (7), the butyl rubber becomes low-molecular-weight. Furthermore, when the butyl rubber is reduced in molecular weight, the adhesive layer 2 containing such reduced molecular weight butyl rubber deteriorates in a way that causes it to soften.

[0070] <(c) Termination reaction> As described above, while the chain growth reaction proceeds, the various radicals generated by the chain growth reaction also begin to react with each other. Then, once all the generated radicals have disappeared, the chain growth reaction stops (termination reaction). Examples of termination reactions include, for example, the reaction in which a primary radical R· reacts with a hydrogen radical H· to produce RH as a product (see equation (8) in Figure 2), the reaction in which two primary radicals R· react to produce RR as a product (see equation (9) in Figure 2), and the reaction in which two radicals RO· react to produce ROOR as a product (see equation (10) in Figure 2). In this case, if the termination reaction yields products such as RR or ROOR, the butyl rubber becomes polymerized. Furthermore, if the butyl rubber is polymerized, the adhesive layer 2 containing such polymerized butyl rubber will deteriorate in a way that causes it to harden.

[0071] As described above, in the auto-oxidation reaction, the butyl rubber contained in the adhesive layer 2 deteriorates due to a radical reaction. In this case, if the adhesive layer 2 contains the primary antioxidant, the various radicals generated in the adhesive layer 2 can be preferentially reacted with the primary antioxidant, thereby stabilizing the radical species. This makes it possible to suppress the progress of the auto-oxidation reaction in the adhesive layer 2. Furthermore, if the adhesive layer 2 contains the secondary aging inhibitor, it can decompose the hydroperoxide (ROOH) that is generated in the adhesive layer 2 as described above. In this manner, the auto-oxidation reaction can be suppressed from proceeding in the adhesive layer 2.

[0072] Incidentally, the adhesive layer 2 may contain, in addition to the butyl rubber, a diene rubber such as styrene-isoprene-styrene block copolymer (SIS) as the rubber component. Furthermore, diene rubbers like SIS have a larger number of carbon-carbon double bonds compared to butyl rubber, and therefore also have a larger number of carbon atoms at the α-position adjacent to the carbon-carbon double bonds compared to butyl rubber. Therefore, compared to butyl rubber, the diene-based rubber is more susceptible to the extraction of hydrogen (H) from the α-position carbon (C) as shown in formula (1) in Figure 2, and radicals derived from the diene-based rubber (hereinafter also referred to as 1' radicals) are more easily generated. Furthermore, some of these first' radicals attack the α-position carbon in the butyl rubber and act to extract hydrogen from the α-position carbon in the butyl rubber, thus making it easier for the first radical to be generated. Therefore, when the adhesive layer 2 contains the diene-based rubber, the auto-oxidation reaction is more likely to occur in the butyl rubber. However, as described above, if the adhesive layer 2 contains the primary antioxidant, the various radicals generated in the auto-oxidation reaction of the diene rubber can be stabilized by the primary antioxidant. Furthermore, as described above, if the adhesive layer 2 contains the secondary aging inhibitor, the hydroperoxide (ROOH) produced by the auto-oxidation reaction can be decomposed by the secondary aging inhibitor. In other words, even when the adhesive layer 2 contains the diene-based rubber in addition to the butadiene rubber, the presence of at least one of the primary aging inhibitor and the secondary aging inhibitor in the adhesive layer 2 can suppress the deterioration of the butyl rubber in the adhesive layer 2.

[0073] The adhesive layer 2 may contain inorganic components. The adhesive layer 2 may contain inorganic fillers and inorganic colorants as inorganic components. The adhesive layer 2 preferably contains an inorganic filler as an inorganic component.

[0074] Examples of the inorganic fillers include calcium carbonate (for example, heavy calcium carbonate or light calcium carbonate), talc, titanium dioxide, silica, and magnesium oxide. Among these, calcium carbonate is preferred. The content of the inorganic filler in the adhesive layer 2 is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more. Furthermore, the content of the inorganic filler in the adhesive layer 2 is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less.

[0075] As the inorganic coloring agent, carbon is preferably used, and carbon black is more preferably used.

[0076] The adhesive layer 2 preferably contains 500 parts by mass or less of the inorganic component, more preferably 450 parts by mass or less, and even more preferably 400 parts by mass or less, per 100 parts by mass of the rubber component. Furthermore, the adhesive layer 2 preferably contains 50 parts by mass or more of the inorganic component, and more preferably 150 parts by mass or more, per 100 parts by mass of the rubber component.

[0077] In the adhesive layer 2, the mass value W of the inorganic component I The value of the mass of the organic component W O The ratio (W O / W I It is preferable that the ratio is between 0.5 and 1.3. As a result, the adhesive sheet 10 can exhibit more sufficient adhesiveness over a wide temperature range, from low to high temperatures. W O / W I It is more preferable that it be 0.7 or higher, and even more preferable that it be 0.8 or higher. Also, W O / W I It is more preferably 1.2 or less, and even more preferably 1.0 or less.

[0078] In the adhesive layer 2, the ratio of the butyl rubber content to the inorganic component content (butyl rubber content / inorganic component content) is preferably 0.15 or higher, and more preferably 0.20 or higher. Furthermore, in the adhesive layer 2, the ratio of the butyl rubber content to the inorganic component content is preferably 0.45 or less, and more preferably 0.30 or less.

[0079] In the adhesive sheet 10, it is preferable that the oxidation start temperature of the adhesive layer 2, as measured using a chemiluminescence analyzer, is 200°C or higher. Furthermore, the oxidation start temperature of the adhesive layer 2 is more preferably 220°C or higher, more preferably 240°C or higher, more preferably 250°C or higher, and more preferably 260°C or higher. The upper limit of the oxidation initiation temperature for the adhesive layer 2 is typically 300°C. Because the oxidation initiation temperature of the adhesive layer 2 is within the above numerical range, the adhesive layer 2 is less susceptible to degradation due to oxidation. This results in the adhesive sheet 10 having superior long-term durability.

[0080] The oxidation start temperature of the adhesive layer 2, measured using a chemiluminescence analyzer, can be determined, for example, by using a chemiluminescence analyzer such as "CLA-FS4" manufactured by Tohoku Electronics Industry Co., Ltd., under the following conditions. After obtaining a graph with temperature on the horizontal axis and luminescence intensity on the vertical axis, the graph can be analyzed as follows. Measurement conditions ·Measurement temperature: 30℃~350℃ • Heating conditions: 5°C / min • Atmosphere: Oxygen (O2) • Measurement item: Luminous intensity (Count Pre Sce) • Minimum measurement time: 1 sec • Spectroscopic filters: 20 built-in • Measurement sample chamber: CLS-SH1 (flow type) • Planar dimensions of the measurement sample: Thickness 0.2mmt, φ20mm (cut from adhesive layer 2) Graph analysis (1) Read the value of the luminescence intensity (Ei1) when the measurement start temperature is 30°C. (2) The highest peak detected in the graph is taken as the peak top, and the value of the luminous intensity (Ei2) corresponding to the peak top is read. (3) Calculate the value obtained by subtracting Ei1 from Ei2 (ΔEi). (4) Read the temperature value in the graph when the luminescence intensity becomes 10% of ΔEi, and set this temperature value as the oxidation start temperature of the adhesive layer 2.

[0081] In the adhesive sheet 10, it is preferable that the ratio (G2' / G1') of the storage modulus of the adhesive layer 2 at -10°C to the storage modulus of the adhesive layer 2 at 60°C G1' is less than 12. Furthermore, in the adhesive sheet 10, it is preferable that the storage modulus value G2' of the adhesive layer 2 at -10°C is 0.7 MPa or less. As G1' and G2' satisfy the above relationship, the adhesive layer 2 will have an appropriate modulus of elasticity over a wide temperature range from low temperatures (e.g., -10°C) to high temperatures (e.g., 60°C). Therefore, such an adhesive layer 2 can exhibit good conformability to the adherend (such as a breathable waterproof sheet or interior walls in a house) over a wide temperature range from low to high temperatures.

[0082] G2' / G1' is preferably 11 or less. The ratio of G2' / G1' is preferably 3 or greater, and more preferably 5 or greater. G2' is preferably 0.6 MPa or less, and more preferably 0.5 MPa or less. G2' is preferably 0.1 MPa or higher, and more preferably 0.2 MPa or higher. G1' is preferably between 0.03 MPa and 0.06 MPa.

[0083] For the adhesive layer 2, the storage modulus value G1' at 60°C and the storage modulus value G2' at -10°C can be determined by performing dynamic viscoelasticity measurements using the Rheometric ARES dynamic viscoelasticity measuring instrument under the following conditions. For the measurement sample, a portion of the adhesive taken from adhesive layer 2 is pressed to a thickness of 2 mm under the conditions of 80°C for 1 minute. • Equipment: ARES (Advanced Rheometric Expansion System) manufactured by Rheometric Scientific. • Frequency: 1Hz ·Temperature: -30~120℃ • Heating rate: 5°C / min • Transformation mode: Twist • Shape: Parallel plate (7.9mmφ) Note that G1' is the value at 60°C in the above measurement, and G2' is the value at -10°C in the above measurement.

[0084] In the adhesive sheet 10, it is preferable that the adhesive layer 2 has an adhesive strength of 2.0 N / 25 mm or more at -10°C. The adhesive layer 2 is more preferably 3.0 N / 25 mm or more, and more preferably 5 N / 25 mm or more, at -10°C. As a result, the adhesive layer 2 can exhibit sufficient adhesion even at low temperatures such as -10°C, where a decrease in tackiness can be particularly noticeable. The upper limit of the adhesive strength of adhesive layer 2 at -10°C is typically 20.0 N / 25 mm.

[0085] The adhesive layer 2 preferably has an adhesive strength of 9.0 N / 25 mm or more at 23°C, and more preferably 11.0 N / 25 mm or more. As a result, the adhesive layer 2 can exhibit sufficient tackiness even at room temperature, such as 23°C. The upper limit of the adhesive strength of adhesive layer 2 at 23°C is typically 30.0 N / 25 mm.

[0086] The adhesive layer 2 preferably has an adhesive strength of 2.0 N / 25 mm or more at 60°C, more preferably 4.0 N / 25 mm or more, and even more preferably 6.0 N / 25 mm or more. As a result, the adhesive layer 2 can exhibit sufficient adhesion even at high temperatures such as 60°C. The upper limit of the adhesive strength of the adhesive layer 2 at 60°C is typically 20.0 N / 25 mm.

[0087] The adhesive strength of the adhesive layer 2 at each evaluation temperature (-10°C, 23°C, and 60°C) can be measured according to the following procedure. (1) Cut out a 25mm wide test piece from the adhesive sheet 10. (2) The test specimen and the adherend, a breathable waterproof sheet (Lamitect Hi (product number RI-100-50), manufactured by Seiren Co., Ltd.), are cured for 1 hour at each evaluation temperature (-10°C, 23°C, and 60°C). (3) After the test specimen and the moisture-permeable waterproof sheet have been cured, the adhesive layer 2 of the test specimen is attached to one side of the moisture-permeable waterproof sheet in each evaluation temperature atmosphere, and the test specimen is pressed onto the moisture-permeable waterproof sheet by moving a roller with a mass of 2 kg back and forth once. (4) After curing for an additional 30 minutes at each evaluation temperature, the adhesive strength of the adhesive layer 2 to the moisture-permeable waterproof sheet is measured under the conditions of a peeling angle of 180° and a peeling speed of 300 mm / min. The above measurements were performed on three samples for each evaluation temperature, and the adhesive strength of the adhesive layer 2 at each evaluation temperature was determined by taking the arithmetic mean of the measured values ​​for the three samples. Furthermore, as shown in Figure 3, when measuring the adhesive strength of an adhesive sheet 10' (double-sided adhesive sheet) having a base material 1, a first adhesive layer 2a laminated on one side of the base material 1, and a second adhesive layer 2b laminated on the other side of the base material 1, a backing material is attached to the adhesive layers that are not to be measured for adhesive strength, and then the adhesive strength of the adhesive layers that are to be measured is measured according to the procedure described above. For example, in the adhesive sheet 10' shown in Figure 3, if the first adhesive layer 2a is the target of adhesive strength measurement and the second adhesive layer 2b is not, then a backing material is attached to the second adhesive layer 2b, and then the adhesive strength of the first adhesive layer 2a is measured. The backing material may include thin printing paper with a width of 30 mm, or polyethylene terephthalate film with a thickness of 25 ± 2.5 μm as specified in JIS C 2318 (hereinafter referred to as PET film), or PET film of equivalent or higher quality. The aforementioned thin printing paper has a basis weight of 40 g / m². 2 This refers to the printing paper described above, and includes, for example, India paper used in dictionaries, and type / copy paper. Furthermore, when measuring the adhesive strength of the adhesive layer at -10°C and at 23°C, it is preferable to use PET film as the backing material, and when measuring the adhesive strength of the adhesive layer at 60°C, it is preferable to use thin printing paper as the backing material.

[0088] The thickness of the adhesive layer 2 is preferably 50 μm or more, and more preferably 100 μm or more. Furthermore, the thickness of the adhesive layer 2 is preferably 500 μm or less, and more preferably 400 μm or less.

[0089] As the base material 1, a sheet made from various known materials can be used. The base material 1 is preferably composed of one of the sheets selected from the group consisting of fiber sheets, rubber sheets, plastic sheets, metal sheets, and foam sheets. Since the base material 1 is composed of any sheet selected from the above group, it becomes easier to form the adhesive layer 2 on the base material 1 with a relatively uniform thickness. Furthermore, the adhesive layer 2 can be suitably held on the substrate 1. Furthermore, since plastic sheets and metal sheets among the sheets included in the above group generally have high tensile strength, the waterproofness and durability of the adhesive sheet 10 can be improved by constructing the base material 1 from these sheets. Furthermore, among the sheets included in the above group, fiber sheets, rubber sheets, and foam sheets generally have high flexibility. Therefore, by constructing the base material 1 from these sheets, it is possible to adequately conform to adherends that have irregularities on their surface. Among these, the base material 1 is preferably composed of a fiber sheet.

[0090] Examples of fibers constituting the fiber sheet include synthetic resin fibers, metal fibers, and natural fibers, and among these, synthetic resin fibers are preferred. Examples of the synthetic resin fibers include fibers made from thermoplastic resins and thermosetting resins. The synthetic resin fiber is preferably a fiber made of a thermoplastic resin.

[0091] Examples of the thermoplastic resins include polyolefin resins such as polyethylene (PE) and polypropylene (PP); polyester resins such as polyethylene terephthalate (PET); polyamide resins such as polyamide 6 and polyamide 6,6; and cellulose resins. These thermoplastic resins may be used individually or in combination of two or more types. Among these, the thermoplastic resin is preferably a polyester resin or a polyolefin resin, and more preferably polyethylene terephthalate or polypropylene.

[0092] If the base material 1 is composed of a fiber sheet, the fiber sheet is preferably a nonwoven fabric sheet or a woven fabric sheet. In other words, the fiber sheet is preferably composed of a nonwoven fabric sheet or a woven fabric sheet.

[0093] The nonwoven fabric sheet may be manufactured using various known methods. Various known manufacturing methods include, for example, the dry method, wet method, spunbond method, thermal bond method, chemical bond method, stitch bond method, needle punch method, melt blow method, spunlace method, and steam jet method. Commercially available nonwoven fabric sheets can be used.

[0094] The basis weight of the nonwoven fabric sheet is 25 g / m². 2 Preferably, it is 30 g / m 2 It is more preferable that the amount be greater than or equal to 40 g / m 2 It is even more preferable that the above conditions are met. Furthermore, the basis weight of the nonwoven fabric sheet is 80g / m². 2 Preferably, it is 70 g / m 2 The following is preferable: By keeping the basis weight within the above numerical range, the adhesive sheet 10 can be made to have sufficient tensile strength, and it is also possible to suppress the tendency for the adhesive sheet 10 to peel off the application target due to excessive rigidity of the base material 1.

[0095] Woven sheets can be manufactured using various known looms. The woven sheet may be made using any type of weaving method. Examples of weaving methods for woven sheets include plain weave, twill weave, and satin weave. Commercially available woven fabric sheets can be used.

[0096] The thickness of the substrate 1 is preferably 60 μm or more, and more preferably 80 μm or more. Furthermore, the thickness of the substrate 1 is preferably 500 μm or less, and more preferably 400 μm or less.

[0097] The adhesive layer 2 can be obtained by mixing the above-mentioned organic and inorganic components in the above-mentioned amounts, kneading the resulting adhesive composition, and then forming (applying adhesive to) the composition into a sheet on the substrate 1.

[0098] For the aforementioned mixing, batch-type kneaders such as kneaders, Banbury mixers, and mixing rolls, or continuous kneaders such as twin-screw kneaders, are used, and for sheet-shaped forming, forming equipment such as extruders, calender rolls, and presses (hot presses) are used.

[0099] A sealing layer 3 may be provided between the substrate 1 and the adhesive layer 2, as shown in Figure 1B. The sealing layer 3 is a barrier layer that prevents components contained in the adhesive layer 2 from penetrating the substrate 1.

[0100] It is preferable to use a thermoplastic resin as the material constituting the sealing layer 3 (sealing material). Examples of thermoplastic resins include polyolefin resins such as ethylene-vinyl acetate copolymer, polyethylene, and polypropylene; and polyester resins such as polyethylene terephthalate. These thermoplastic resins may be used individually or in combination of two or more types. Among these, the thermoplastic resin is preferably a polyolefin resin, and more preferably polyethylene.

[0101] The sealing layer 3 can be laminated onto the substrate 1 by, for example, heating and melting a sealing material and applying the molten material to one side of the substrate 1. Methods for applying molten material include the doctor blade method, calender roll coating, screen coating, and gravure coating. Furthermore, the sealing layer 3 can be laminated onto the substrate 1 by transferring it to the substrate 1 via an adhesive.

[0102] The thickness of the sealing layer 3 is preferably 12 μm or more, and more preferably 15 μm or more. Furthermore, the thickness of the sealing layer 3 is preferably 35 μm or less, and more preferably 25 μm or less.

[0103] As described above with reference to Figures 1A and 1B, an adhesive sheet 10 according to one embodiment of the present invention is described as a single-sided adhesive sheet in which an adhesive layer 2 is laminated on one side of a base material 1. However, as shown in Figure 3, the adhesive sheet according to the present invention may also be a double-sided adhesive sheet in which adhesive layers are laminated on both sides of the base material. In other words, an adhesive sheet 10' according to another embodiment of the present invention may have a base material 1, a first adhesive layer 2a laminated on one side of the base material 1, and a second adhesive layer 2b laminated on the other side of the base material 1, as shown in Figure 3. As described above, by interposing the substrate 1 between the first adhesive layer 2a and the second adhesive layer 2b, component migration between each adhesive layer can be suppressed.

[0104] In such a double-sided adhesive sheet, one adhesive layer (for example, the first adhesive layer 2a) is attached to the breathable waterproof sheet in the same way as described for the single-sided adhesive sheet. Therefore, for example, if the first adhesive layer 2a is an adhesive layer that is attached to a breathable waterproof sheet, the first adhesive layer 2a is configured in the same way as the adhesive layer 2 of the adhesive sheet 10 according to one embodiment of the present invention. On the other hand, the other adhesive layer (for example, the second adhesive layer 2b) is attached to the object to be constructed, such as the interior wall of a house. Therefore, if the second adhesive layer 2b is an adhesive layer that is attached to an object to be constructed, such as an interior wall in a house, the second adhesive layer 2b may be configured in the same way as the first adhesive layer 2a, or it may be configured differently.

[0105] When the second adhesive layer 2b has a different configuration from the first adhesive layer 2a, from the viewpoint of ensuring sufficient adhesion of the second adhesive layer 2b to the object being applied, the second adhesive layer 2b may consist of, for example, 100 parts by mass of a rubber component containing 40-93% by mass of butyl rubber and 7-60% by mass of polyisobutylene, as described in Japanese Patent Publication No. 2013-189523 and Japanese Patent Publication No. 2015-54888, and a kinematic viscosity at 40°C of 100-9000 mm². 2 It is preferable to use an adhesive composition formed with 82 to 128 parts by mass of a softening agent at / s, an adhesive composition formed with a butyl rubber base and a crosslinking agent for crosslinking the butyl rubber, as described in Japanese Patent Application Publication No. 2003-213231, and an adhesive composition formed with a crosslinking agent that includes (a) a rubbery polymer, (b) a tackifier, and (c) a crosslinking agent selected from thiram vulcanizing agent, quinoid vulcanizing agent, quinone dioxime vulcanizing agent, and maleimide vulcanizing agent, as described in Japanese Patent Application Publication No. 2003-41233. Furthermore, the composition of the second adhesive layer 2b will be selected to be suitable for the application.

[0106] In the adhesive sheet 10' according to another embodiment of the present invention, the first adhesive layer 2a and the second adhesive layer 2b can be obtained by kneading each adhesive composition (composition for the first adhesive layer and composition for the second adhesive layer) in a batch-type kneader or a continuous kneader, as described in the adhesive sheet 10 according to one embodiment of the present invention, and then forming them into sheets on both sides of the base material 1 using a molding device such as an extruder.

[0107] The adhesive sheet according to this embodiment is used to attach a breathable waterproof sheet to construction materials and other objects used in building and civil engineering works.

[0108] The applications for this coating include materials that require breathable waterproofing, such as building materials for houses (peripheral parts around windows, framing, roofing materials, walls, etc.) and components for construction and civil engineering works (penetrations, joints, etc.). In other words, the adhesive sheet according to the present invention is used as a waterproof tape for residential use.

[0109] A breathable waterproof sheet is made up of a resin sheet with multiple micropores that penetrate in the thickness direction, or a nonwoven fabric with gaps between the fibers. Moisture can pass through the micropores and gaps, but rainwater is blocked. The breathable waterproof sheet is not particularly limited as long as it has the above-mentioned functions, and examples include those described in Japanese Patent Publication No. 2006-241769, Japanese Patent Publication No. 2004-003225, and Japanese Patent Publication No. 2004-002577. Breathable waterproof sheets are typically made larger than adhesive sheets.

[0110] The matters disclosed herein include the following:

[0111] (1) Substrate and An adhesive sheet having an adhesive layer laminated on at least one side of the substrate, The adhesive layer contains butyl rubber as an organic component. The molecular weight retention rate of the butyl rubber after heating at 100°C for 7 weeks is 20% or more. Adhesive sheet.

[0112] Heating the adhesive sheet at 100°C for seven weeks is equivalent to an "accelerated degradation test" in which the degradation of the butyl rubber in the adhesive layer, which would normally occur over a long period, progresses in a short time by exposing the adhesive sheet to harsh conditions. In the above configuration, the retention rate of the molecular weight of the butyl rubber in this accelerated degradation test is relatively high, at 20% or more. Therefore, the adhesive layer will exhibit sufficient adhesion to the application surface (for example, the interior walls of a house) over a long period of time. In other words, the adhesive sheet having the adhesive layer described above will have excellent long-term durability.

[0113] (2) The adhesive strength of the adhesive layer at -10℃ is 2.0 N / 25 mm or more. The adhesive strength of the adhesive layer at 60°C is 2.0 N / 25 mm or more. The adhesive sheet described in (1) above.

[0114] With this configuration, the adhesive sheet will not only have excellent long-term durability, but will also be able to exhibit sufficient adhesiveness over a wide temperature range from low temperatures of -10°C to high temperatures of 60°C.

[0115] (3) The oxidation onset temperature of the adhesive layer, as measured using a chemiluminescence analyzer, is 200°C or higher. The adhesive sheet described in (1) or (2) above.

[0116] With this configuration, the adhesive layer is less susceptible to deterioration due to oxidation. As a result, the adhesive sheet will have superior long-term durability.

[0117] (4) The ratio (G2' / G1') of the storage modulus of the adhesive layer at -10°C G2' to the storage modulus of the adhesive layer at 60°C G1' is less than 12. The storage modulus value G2' of the adhesive layer at -10℃ is 0.7 MPa or less. The adhesive sheet described in any of (1) to (3) above.

[0118] With this configuration, the adhesive sheet will not only have excellent long-term durability, but will also be able to exhibit sufficient adhesiveness over a wide temperature range from low temperatures of -10°C to high temperatures of 60°C.

[0119] (5) The adhesive layer further contains inorganic components, The mass value W of the inorganic component I The value of the mass of the organic component W O The ratio (WO / W I ) is between 0.5 and 1.3 The adhesive sheet described in any of (1) to (4) above.

[0120] With this configuration, the adhesive sheet will not only have excellent long-term durability, but will also be able to exhibit sufficient adhesiveness over a wide temperature range from low temperatures of -10°C to high temperatures of 60°C.

[0121] (6) The adhesive layer further comprises a thermoplastic elastomer as the organic component. The adhesive sheet described in any of (1) through (5) above.

[0122] With this configuration, the adhesive sheet will not only have excellent long-term durability, but will also be able to exhibit sufficient adhesiveness over a wide temperature range from low temperatures of -10°C to high temperatures of 60°C.

[0123] (7) The thermoplastic elastomer is at least one of a styrene-based thermoplastic elastomer and an acrylic-based thermoplastic elastomer. The adhesive sheet described in (6) above.

[0124] With this configuration, the adhesive sheet will not only have excellent long-term durability, but will also be able to exhibit sufficient adhesiveness over a wide temperature range from low temperatures of -10°C to high temperatures of 60°C.

[0125] (8) The adhesive layer contains 1 part by mass or more of the thermoplastic elastomer with respect to 100 parts by mass of the total amount of the butyl rubber and the thermoplastic elastomer. The adhesive sheet described in (6) or (7) above.

[0126] With this configuration, the adhesive sheet will not only have excellent long-term durability, but will also be able to exhibit sufficient adhesiveness over a wide temperature range from low temperatures of -10°C to high temperatures of 60°C.

[0127] (9) The styrene-based thermoplastic elastomer has a diblock rate of 10% to 70%. The adhesive sheet described in (8) above.

[0128] With this configuration, the adhesive sheet will not only have excellent long-term durability, but will also be able to exhibit sufficient adhesiveness over a wide temperature range from low temperatures of -10°C to high temperatures of 60°C.

[0129] (10) The adhesive layer includes an inorganic filler as the inorganic component. The adhesive sheet described in (5) above.

[0130] With this configuration, the inclusion of the inorganic filler makes it easier to ensure the thickness of the adhesive sheet.

[0131] (11) The content of the inorganic filler in the adhesive layer is 20% by mass or more. The adhesive sheet described in (10) above.

[0132] With this configuration, it becomes easier to ensure a sufficient thickness for the adhesive sheet.

[0133] (12) The adhesive layer further comprises an anti-aging agent as the organic component. The adhesive sheet described in any of (1) through (11) above.

[0134] With this configuration, the adhesive layer becomes less susceptible to deterioration due to oxidation. As a result, the adhesive sheet will have superior long-term durability.

[0135] (13) The aforementioned antioxidant includes at least one selected from the group consisting of phenolic antioxidants, amine antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants. The adhesive sheet described in (12) above.

[0136] With this configuration, the adhesive layer becomes even less susceptible to deterioration due to oxidation. As a result, the adhesive sheet will have even better long-term durability.

[0137] (14) The aforementioned antioxidant comprises at least one selected from a first group consisting of phenolic antioxidants and amine-based antioxidants, and at least one selected from a second group consisting of phosphorus-based antioxidants and sulfur-based antioxidants. The adhesive sheet described in (12) or (13) above.

[0138] With this configuration, the adhesive layer becomes even less susceptible to deterioration due to oxidation. As a result, the adhesive sheet will have even better long-term durability.

[0139] (15) The substrate is composed of any sheet selected from the group consisting of fiber sheets, rubber sheets, plastic sheets, metal sheets, and foam sheets. An adhesive sheet as described in any of (1) through (14) above.

[0140] With this configuration, it becomes easier to form the adhesive layer with a relatively uniform thickness. Furthermore, the adhesive layer can be effectively held in place. Furthermore, since plastic sheets and metal sheets among the sheets included in the above group generally have high tensile strength, the waterproofness and durability of the adhesive sheet can be improved by constructing the base material from these sheets. Furthermore, by using sheets from the above group to form the base material, it is possible to adequately conform to adherends that have irregularities on their surface.

[0141] (16) The aforementioned fiber sheet is a nonwoven fabric sheet or a woven fabric sheet. The adhesive sheet described in (15) above.

[0142] With this configuration, it becomes easier to form the adhesive layer with a relatively uniform thickness. Furthermore, the adhesive layer can be held more effectively.

[0143] The adhesive sheet according to the present invention is not limited to the embodiments described above. Furthermore, the adhesive sheet according to the present invention is not limited to the effects and advantages described above. Furthermore, the adhesive sheet according to the present invention can be modified in various ways without departing from the spirit of the invention. [Examples]

[0144] Next, the present invention will be described in more detail with reference to examples. The following examples are provided to further illustrate the present invention and do not limit its scope.

[0145] First, let's explain the raw materials shown in Table 1 below. (1) Rubber component (a) Butyl rubber (IIR) ·JSR BUTYL 268 (manufactured by JSR, mass average molecular weight 500,000) (b) Thermoplastic elastomers • Styrene-isoprene-styrene block copolymer (SIS) SIS1: Styrene content 16% by mass, diblock rate 56% • Styrene-isobutylene-styrene block copolymer (SIBS) SIBS1: Styrene content 20% by mass, diblock content 41% SIBS2: styrene content 20% by mass, diblock ratio 46% (2) Tackifier Tackifier 1: TREZ RC093 (manufactured by Nippon Petrochemicals Co., Ltd., C5 hydrocarbon, mass average molecular weight 1440, softening point 94°C) Tackifier 2: TREZ RB100 (manufactured by Nippon Petrochemicals Co., Ltd., C5 hydrocarbon, mass average molecular weight 3090, softening point 98°C) (3) Softener ·Polyisobutylene (PIB) Polyisobutylene 1: Tetrax 5T (manufactured by Nippon Petrochemicals Co., Ltd., mass average molecular weight 50,000) Polyisobutylene 2: HV-300 (manufactured by Nippon Petrochemicals Co., Ltd., number average molecular weight 1400, kinematic viscosity at 40°C 26000 mm 2 / s) Polyisobutylene 3: HV-15 (manufactured by Nippon Petrochemicals Co., Ltd., number average molecular weight 630, kinematic viscosity at 40°C 655 mm 2 / s) (4) Inorganic filler Heavy calcium carbonate (manufactured by Maruo Calcium Co., Ltd., sieve residue (350 mesh) 0.5% or less (based on JIS K5101)) (5) Colorant Carbon: Seast 3H (manufactured by Tokai Carbon Co., Ltd., carbon black) (6) Anti-aging agent ·Primary anti-aging agent Amine-based anti-aging agent 1: Nocrac 6C (manufactured by Ouchi Shinko Chemical Industrial Co., Ltd.) Amine-based anti-aging agent 2: Nocrac White (manufactured by Ouchi Shinko Chemical Industrial Co., Ltd.) Amine-based anti-aging agent 3: Nocrac CD (manufactured by Ouchi Shinko Chemical Industrial Co., Ltd.) Phenolic anti-aging agent 1: Nocrac NS-6 (manufactured by Ouchi Shinko Chemical Industrial Co., Ltd.) Phenolic anti-aging agent 2: Songnox 1010 (manufactured by SONGWON) ·Composite anti-aging agent (primary anti-aging agent + secondary anti-aging agent) Composite anti-aging agent 1: Irganox 565 (manufactured by BASF) ·Secondary anti-aging agent Phosphorus-based anti-aging agent 1: Irgafos 168 (manufactured by BASF) Table 1 also shows the mass ratio (mass%) of organic components, the mass ratio (mass%) of inorganic components, the ratio of the mass of organic components to the mass of inorganic components, the ratio of butyl rubber to the mass of inorganic components, and the ratio of the mass of butyl rubber to the mass of tackifier in the adhesive composition.

[0146] Adhesive compositions according to Examples 1-8 and Comparative Examples 1-4 were obtained by blending rubber components (butyl rubber and thermoplastic elastomer), tackifiers, softeners, inorganic fillers, colorants, and antioxidants in the proportions (parts by mass) shown in Table 1 below, while heating. Specifically, the adhesive compositions for each example were obtained by heating the liquid to 140°C using a kneader.

[0147] Next, the adhesive composition for each example was coated onto one side of a substrate (polyethylene terephthalate nonwoven fabric (thickness 100 μm)). Specifically, one side of the substrate was coated with a coating to a thickness of 0.2 mm using four 8-inch calender rolls while heating to 80°C. This resulted in obtaining adhesive sheets for each example.

[0148] [Table 1]

[0149] [Storage modulus] For each example of adhesive sheet, the storage modulus G1' of the adhesive layer at 60°C and the storage modulus G2' of the adhesive layer at -10°C were measured. The storage moduli G1' and G2' were measured by the method described in the Embodiments section above. The results of measuring the storage moduli G1' and G2' are shown in Table 2 below. Furthermore, Table 2 below shows the ratio of the storage modulus G2' to the storage modulus G1' (G2' / G1').

[0150] [Oxidation start temperature] For each example of adhesive sheet, the oxidation initiation temperature of the adhesive layer was measured using a chemiluminescence analyzer. The oxidation start temperature of the adhesive layer was measured by the method described in the above embodiment section. The results of measuring the oxidation initiation temperature of the adhesive layer are shown in Table 2 below.

[0151] [Molecular weight maintenance rate] For each example of adhesive sheet, the retention rate of the molecular weight of the butyl rubber was determined. The molecular weight retention rate of the butyl rubber was measured by the method described in the above section on embodiments. The results of measuring the molecular weight retention rate of the butyl rubber are shown in Table 2 below.

[0152] [Adhesive strength] The adhesive strength of the adhesive sheets for each example was measured at -10°C, 23°C, and 60°C. The adhesive strength was measured using the method described in the section on embodiments above. The results of the adhesive strength measurements at each temperature are shown in Table 2 below.

[0153] [Adhesion Stability Test] In accordance with section 5.8 Adhesion Stability Test 10 of JIS A 6112:2019 (Double-Sided Adhesive Waterproof Tape for Residential Use), an adhesion stability test was conducted, and the adhesion stability at 60°C was evaluated. Adhesion stability was evaluated according to the following criteria. • Good: Water leakage has been confirmed. • Defect: No water leakage was detected. The results are shown in Table 2 below.

[0154] [Deviation after heating at 60°C for 5 minutes] A holding strength test was conducted in accordance with section 5.7 "Holding strength test" of JIS A 6112:2019 (Double-sided adhesive waterproof tape for residential use), and the holding strength at 60°C was evaluated. The evaluation results are shown in Table 2 below as displacement after heating at 60°C for 5 minutes.

[0155] [Adhesive strength after heating at 100°C for 7 weeks] After heating the pressure-sensitive adhesive sheet of each example at 100°C for 7 weeks, the adhesive strength of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of each example was measured in accordance with the evaluation method for adhesive durability of JIS A6112. A hard-type Tyvek sheet (trade name "Tyvek Hard Type 1060B", manufactured by Asahi-DuPont Flashspun Products) was used as the adherend. The measurement results of the adhesive strength after heating at 100°C for 7 weeks are shown in Table 2 below.

[0156] [Discoloration] For the pressure-sensitive adhesive sheet of each example, discoloration of the pressure-sensitive adhesive layer was evaluated according to the following procedure. (1) For the pressure-sensitive adhesive sheet of each example, press the pressure-sensitive adhesive layer to a thickness of 0.2 mm. (2) Paste the exposed surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet of each example onto a hard-type Tyvek sheet (trade name "Tyvek Hard Type 1060B", manufactured by Asahi-DuPont Flashspun Products) to obtain a first laminate of the Tyvek sheet and the pressure-sensitive adhesive sheet. (3) Place the first laminate on the SUS304 plate such that the Tyvek sheet is in contact with the SUS304 plate. (4) Peel the substrate from one surface of the first laminate placed on the SUS304 plate to obtain a second laminate of the Tyvek sheet and the pressure-sensitive adhesive layer. (5) After placing the SUS304 plate with the second laminate placed thereon into a heating oven, heat at a temperature of 60°C for 1 day. (6) Take out the SUS304 plate with the second laminate placed thereon from the heating oven, and measure the color difference (b * value) of the exposed surface of the pressure-sensitive adhesive layer in the second laminate. Note that the color difference (b *The values ​​were measured using a multi-angle spectrophotometer (manufactured by X-rite) at a measurement angle of 45°. Color difference (b * The measurement results for the values ​​are shown in Table 2 below. Note that in Table 2 below, the color difference (b * For items with a value of 3 or more, yellowing is detected, and the color difference (b) is evaluated as present. * Items with a value less than 3 are evaluated as having no yellowing.

[0157] [Table 2]

[0158] Table 2 shows that in each example, the molecular weight retention rate of the butyl rubber in the adhesive sheet after heating at 100°C for 7 weeks was 20% or more. From this, it can be said that the adhesive sheets according to each embodiment have excellent long-term durability. In contrast, it can be seen that in the adhesive sheets of each comparative example, the molecular weight retention rate of the butyl rubber after heating at 100°C for 7 weeks is less than 15%. From this, it can be said that the adhesive sheets in each comparative example cannot fully demonstrate long-term durability. Furthermore, Table 2 shows that the adhesive sheets according to each example exhibit excellent adhesiveness over a wide range from low temperatures (-10°C) to high temperatures (60°C). In contrast, it can be seen that the adhesive sheet according to Comparative Example 1 does not exhibit sufficient adhesiveness at low temperatures. Furthermore, it can be seen that the adhesive sheets in each embodiment all exhibit excellent adhesion stability at 60°C. From this, it can be seen that the adhesive sheets according to each embodiment can exhibit excellent retention properties on the object to be adhered to at 60°C. Furthermore, it can be seen that in the adhesive sheets according to each example, the evaluation of discoloration (yellowing) of the adhesive layer was "none," whereas in the adhesive sheet according to Comparative Example 3, the evaluation of discoloration (yellowing) of the adhesive layer was "present." This is thought to be because, in the adhesive sheet of Comparative Example 3, the adhesive layer contained an amine-based antioxidant 1 that did not suppress the coloring (contamination) of the rubber component. [Explanation of Symbols]

[0159] 1 Base material 2. Adhesive layer 2a 1st adhesive layer 2b Second adhesive layer 3. Sealing layer 10 Adhesive Sheets 10' Adhesive Sheet

Claims

1. Substrate and An adhesive sheet having an adhesive layer laminated on at least one side of the substrate, The adhesive layer comprises butyl rubber, polyisobutylene, styrene-based thermoplastic elastomer, and an anti-aging agent as organic components. The styrene-based thermoplastic elastomer comprises at least one of styrene-isoprene-styrene block copolymer and styrene-isobutylene-styrene block copolymer. The aforementioned adhesive layer contains an inorganic filler as an inorganic component, The molecular weight retention rate of the butyl rubber after heating at 100°C for 7 weeks is 50% or more. Adhesive sheet.

2. The adhesive strength of the adhesive layer at -10°C is 2.0 N / 25 mm or more. The adhesive strength of the adhesive layer at 60°C is 2.0 N / 25 mm or more. The adhesive sheet according to claim 1.

3. The oxidation onset temperature of the adhesive layer, as measured using a chemiluminescence analyzer, is 200°C or higher. The adhesive sheet according to claim 1 or 2.

4. The storage modulus of the adhesive layer at 60°C is G. １ The storage modulus of the adhesive layer at -10°C for 'G ２ ' ratio (G ２ ' / G １ ') is less than 12, The storage modulus of the adhesive layer at -10°C is G. ２ ' is 0.7 MPa or less The adhesive sheet according to claim 1 or 2.

5. The mass value W of the inorganic component Ｉ relative to the mass value W of the organic component Ｏ the ratio (W Ｏ / W Ｉ ) is 0.5 to 1.3 inclusive The adhesive sheet according to claim 1 or 2.

6. The styrene-based thermoplastic elastomer comprises the styrene-isoprene-styrene block copolymer The adhesive sheet according to claim 1 or 2.

7. The adhesive layer contains 1 part by mass or more of the styrene-based thermoplastic elastomer with respect to 100 parts by mass of the total amount of the butyl rubber and the styrene-based thermoplastic elastomer. The adhesive sheet according to claim 1 or 2.

8. The styrene-based thermoplastic elastomer has a diblock ratio of 10% to 70%. The adhesive sheet according to claim 1 or 2.

9. The content of the inorganic filler in the adhesive layer is 20% by mass or more. The adhesive sheet according to claim 1 or 2.

10. The aforementioned antioxidant includes at least one selected from the group consisting of phenolic antioxidants, amine antioxidants, phosphorus antioxidants, and sulfur-based antioxidants. The adhesive sheet according to claim 1 or 2.

11. The aforementioned antioxidant comprises at least one selected from a first group consisting of phenolic antioxidants and amine-based antioxidants, and at least one selected from a second group consisting of phosphorus-based antioxidants and sulfur-based antioxidants. The adhesive sheet according to claim 10.

12. The substrate is composed of any sheet selected from the group consisting of fiber sheets, rubber sheets, plastic sheets, metal sheets, and foam sheets. The adhesive sheet according to claim 1 or 2.

13. The aforementioned fiber sheet is a nonwoven fabric sheet or a woven fabric sheet. The adhesive sheet according to claim 12.

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