Adhesive sheet

Abstract

To provide an adhesive sheet that can exhibit sufficient adhesion in a wide temperature range from low to high temperatures.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. The ratio of the value G2' of the storage elastic modulus at -10°C to the value G1' of the storage elastic modulus at 60°C (G2' / G1') is less than 12, the value G2' of the storage elastic modulus at -10°C is 0.7 MPa or less, and the adhesive force at -10°C is 2.0 N / 25 mm or greater.SELECTED DRAWING: Figure 1

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] As mentioned above, although pressure-sensitive adhesive sheets are required to exhibit excellent adhesiveness over a wide temperature range, it is difficult to say that this requirement has been sufficiently satisfied.

[0006] Accordingly, an object of the present invention is to provide a pressure-sensitive adhesive sheet that can exhibit more sufficient adhesiveness over a wide temperature range from low temperature to high temperature. [Means for Solving the Problem]

[0007] As a result of intensive studies by the present inventor, in a pressure-sensitive adhesive sheet comprising a substrate and a pressure-sensitive adhesive layer laminated on at least one surface of the substrate, the pressure-sensitive adhesive layer contains butyl rubber as an organic component, and the ratio of the storage modulus G2' at -10°C to the storage modulus G1' at 60°C (G2' / G1') is set to less than 12, the storage modulus G2' at -10°C is set to 0.7 MPa or less, and the adhesive strength at -10°C is set to 2.0 N / 25 mm or more. It has been found that the pressure-sensitive adhesive sheet can exhibit more sufficient adhesiveness over a wide temperature range from low temperature to high temperature by the above settings. Thus, the present invention has been completed.

[0008] That is, the pressure-sensitive adhesive sheet according to the present invention is a substrate, 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, the ratio of the storage modulus G2' at -10°C to the storage modulus G1' at 60°C (G2' / G 1 ') is less than 12, the storage modulus G2' at -10°C is 0.7 MPa or less, and the adhesive strength at -10°C is 2.0 N / 25 mm or more. [Effect of the Invention]

[0009] According to the present invention, it is possible to provide an adhesive sheet that can exhibit more sufficient adhesiveness over a wide temperature range from low temperatures to high temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] [Figure 1] FIG. 1 is a cross-sectional view illustrating the configuration of an adhesive sheet according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view illustrating the configuration of an adhesive sheet according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, the adhesive sheet according to the present invention will be described. The adhesive sheet according to the present invention is an adhesive sheet including a base material and an adhesive layer laminated on at least one surface of the base material, wherein the adhesive layer contains butyl rubber as an organic component. Further, in the adhesive sheet according to the present invention, the ratio (G2' / G1') of the storage modulus value G2' at -10°C to the storage modulus value G1' at 60°C of the adhesive layer is less than 12. Furthermore, in the adhesive sheet according to the present invention, the storage modulus value G2' of the adhesive layer at -10°C is 0.7 MPa or less. Furthermore, in the adhesive sheet according to the present invention, the adhesive strength of the adhesive layer at -10°C is 2.0 N / 25 mm or more.

[0012] In the adhesive sheet according to the present invention, the storage modulus value G2' at -10°C is set to 0.7 MPa or less, and the ratio (G2' / G1') of the storage modulus value G2' at -10°C to the storage modulus value G1' at 60°C is set to less than 12. Therefore, in the adhesive sheet according to the present invention, the adhesive layer has an appropriate elastic modulus over a wide temperature range from low temperature (-10°C) to high temperature (60°C), so the adhesive layer can exhibit excellent conformability to an adherend (such as a moisture-permeable waterproof sheet or a construction object such as an inner wall of a house) over a wide temperature range from low to high temperatures. Furthermore, in the adhesive sheet according to the present invention, the adhesive strength of the adhesive layer remains high, at 2N / 25mm or higher, even at low temperatures (-10°C) where a decrease in adhesiveness may be particularly noticeable. Therefore, in the adhesive sheet according to the present invention, the adhesive layer can exhibit sufficient tackiness over a wide temperature range from low to high temperatures. As a result, the adhesive sheet according to the present invention can exhibit more sufficient adhesiveness over a wide temperature range from low to high temperatures.

[0013] In the following, with reference to Figure 1, 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.

[0014] As shown in Figure 1, 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.

[0015] As described above, the adhesive layer 2 contains butyl rubber as an organic component.

[0016] Butyl rubber is a copolymer (isobutylene-isoprene) of isobutene (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.

[0017] The mass-average molecular weight of butyl rubber is preferably between 30,000 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 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. The mass-average molecular weight of butyl rubber can be determined by measuring a sample obtained using the HLC-8420GPC manufactured by TOSOH Corporation under the following conditions. The mass-average molecular weight of butyl rubber is calculated on a polystyrene basis. [Method of obtaining specimens] (1) The sample taken from the adhesive layer 2 containing butyl rubber is 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] • Columns: TSKgel SuperHZM-H, TSKgel SuperHZ4000, TSKgel SuperHZ3000, and TSKgel SuperHZ200 (all manufactured by TOHSOH) connected in series using a ferrule method. • Column size: 6.0mm I.D. × 150mm each ·Eluent:THF ·Flow rate: 0.6mL / min Column temperature: 40°C • Detector: RI ·Injection volume: 20μL

[0018] 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.

[0019] Other types of rubber besides butyl rubber include, for example, 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-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 at least one of a styrene-based thermoplastic elastomer and an acrylic-based thermoplastic elastomer.

[0020] The adhesive layer 2 may contain only a thermoplastic elastomer as the rubber other than the butyl rubber. In such cases, the adhesive layer 2 may contain 70% by mass or more of the butyl rubber and 30% by mass or less of the thermoplastic elastomer, when the sum of the butyl rubber content and the thermoplastic elastomer content is taken as 100% by mass. Furthermore, in the above case, the adhesive layer 2 may contain 80% by mass or more of the butyl rubber and 20% by mass or less of the thermoplastic elastomer. Furthermore, in the above case, the adhesive layer 2 may contain 1% by mass or more of the thermoplastic elastomer, 2% by mass or more, or 3% by mass or more.

[0021] Furthermore, the adhesive layer 2 may contain 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass of synthetic butyl rubber as the butyl rubber. Furthermore, the adhesive layer 2 may contain the butyl rubber as described above, and may also contain only a thermoplastic elastomer as a rubber other than the butyl rubber. The above-mentioned amounts can be used for the butyl rubber content and the thermoplastic elastomer content. By including the butyl rubber and the thermoplastic elastomer in the adhesive layer 2 as described above, the degree to which the adhesive layer 2 contaminates (colors contaminates) the object to be adhered can be reduced.

[0022] 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.

[0023] 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 15% 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).

[0024] 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

[0025] 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.

[0026] Methods for adjusting the diblock ratio in the aforementioned styrene-based thermoplastic elastomer include changing the ratio of polymerization initiator and coupling agent used during polymerization (amount of coupling agent / amount of polymerization initiator).

[0027] The adhesive layer 2 preferably contains 8% by mass or more of rubber components, and more preferably contains 10% 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.

[0028] The adhesive layer 2 may contain organic components other than rubber, such as softeners, tackifiers, and anti-aging agents. The adhesive layer 2 preferably contains a tackifier as an organic component.

[0029] 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.

[0030] The kinematic viscosity of the aforementioned softener at 40°C is 700 mm². 2 Preferably, it should be 900mm or more. 2 It is more preferable that the value be / s or greater. Furthermore, the kinematic viscosity of the softening agent at 40°C is 100,000 mm². 2 It is preferable that it be less than or equal to / s, and 50,000 mm 2 It is more preferable that the value be less than or equal to / s.

[0031] The kinematic viscosity is measured in accordance with JIS K 2283 (2000). Specifically, the kinematic viscosity is measured using a glass capillary viscometer. Furthermore, when using multiple softeners with different kinematic viscosities, the kinematic viscosity is determined as the kinematic viscosity of the mixture of the multiple softeners.

[0032] The adhesive layer 2 preferably contains 30 parts by mass or more of the softening agent per 100 parts by mass of the rubber component, more preferably 50 parts by mass or more, more preferably 130 parts by mass or more, and more preferably 170 parts by mass or more. Furthermore, the adhesive layer 2 preferably contains 400 parts by mass or less of the softening agent, more preferably 300 parts by mass or less, and even more preferably 260 parts by mass or less, per 100 parts by mass of the rubber component.

[0033] Examples of tackifiers include rosin-based resins, terpene-based resins, styrene-based resins, petroleum-based resins, and phenol-based resins, as well as hydrogenated resins obtained by hydrogenating these resins. These tackifiers may be used individually or in combination of two or more types.

[0034] Examples of rosin-based resins include rosin resin, rosin ester resin, and rosin phenol resin. 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.

[0035] 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, more preferably 70 parts by mass or less, more preferably 40 parts by mass or less, and more preferably 30 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.

[0036] Examples of anti-aging agents include phenolic anti-aging agents and phosphorus-based anti-aging agents.

[0037] 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.

[0038] 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 pressure-sensitive adhesive layer 2 is preferably 20% by mass or more, more preferably 30% by mass or more, and still more preferably 35% by mass or more. Further, the content of the inorganic filler in the pressure-sensitive adhesive layer 2 is preferably 90% by mass or less, more preferably 80% by mass or less, and still more preferably 70% by mass or less.

[0039] As the inorganic colorant, carbon is preferably used, and carbon black is more preferably used.

[0040] The pressure-sensitive adhesive layer 2 preferably contains the inorganic component in an amount of 500 parts by mass or less, more preferably 450 parts by mass or less, and still more preferably 400 parts by mass or less, relative to 100 parts by mass of the rubber component. Further, the pressure-sensitive adhesive layer 2 preferably contains the inorganic component in an amount of 50 parts by mass or more, more preferably 150 parts by mass or more, and still more preferably 270 parts by mass or more, relative to 100 parts by mass of the rubber component.

[0041] In the pressure-sensitive adhesive layer 2, the mass value W of the inorganic component I to the mass value W of the organic component O ratio (W O / W I ) is preferably 0.5 or more and 1.3 or less. Thereby, the pressure-sensitive adhesive sheet 10 can exhibit more sufficient adhesiveness in a wide temperature range from low temperature to high temperature. W O / W I is more preferably 0.7 or more, and still more preferably 0.8 or more. Further, W O / W I is more preferably 1.2 or less, and still more preferably 1.0 or less.

[0042] 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.

[0043] As described above, the adhesive layer 2 has a ratio (G2' / G1') of the storage modulus value G2' at -10°C to the storage modulus value G1' at 60°C of less than 12. Furthermore, in the adhesive sheet according to the present invention, the adhesive layer has a storage modulus value G2' of 0.7 MPa or less at -10°C.

[0044] 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.

[0045] 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.

[0046] As described above, the adhesive layer 2 has an adhesive strength of 2.0 N / 25 mm or more at -10°C. The adhesive layer 2 preferably has an adhesive strength of 3.0 N / 25 mm or more at -10°C, and more preferably 5 N / 25 mm or more. Furthermore, the upper limit of the adhesive strength of the adhesive layer 2 at -10°C is typically 20.0 N / 25 mm.

[0047] 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. Furthermore, the upper limit of the adhesive strength of the adhesive layer 2 at 23°C is typically 30.0 N / 25 mm. The adhesive layer 2 preferably has an adhesive strength of 4.0 N / 25 mm or more at 60°C, and more preferably 6.0 N / 25 mm or more. Furthermore, the upper limit of the adhesive strength of the adhesive layer 2 at 60°C is typically 20.0 N / 25 mm.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] The nonwoven fabric sheet may be manufactured using various known methods. Examples of known manufacturing methods include 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.

[0055] 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 surface due to excessive rigidity of the base material 1.

[0056] 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.

[0057] 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.

[0058] The adhesive layer 2 can be obtained by blending the above-mentioned organic and inorganic components in the above-mentioned amounts, kneading the resulting adhesive composition, and then forming (applying adhesive to) the resulting sheet onto the substrate 1.

[0059] 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.

[0060] A sealing layer 3 may be provided between the substrate 1 and the adhesive layer 2, as shown in Figure 1(b). The sealing layer 3 is a barrier layer that prevents components contained in the adhesive layer 2 from penetrating the substrate 1.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] As described above with reference to Figure 1, 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 2, 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 2. 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.

[0065] 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.

[0066] 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. 2It 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 thiraum vulcanizing agents, quinoid vulcanizing agents, quinone dioxime vulcanizing agents, and maleimide vulcanizing agents, 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] The matters disclosed herein include the following:

[0072] (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 ratio of the storage modulus value G2' at -10°C to the storage modulus value G1' at 60°C (G2' / G1') is less than 12. The storage modulus value G2' at -10℃ is 0.7 MPa or less. The adhesive strength at -10℃ is 2.0 N / 25 mm or more. Adhesive sheet.

[0073] With this configuration, the adhesive sheet can exhibit more sufficient adhesiveness over a wide temperature range from low to high temperatures.

[0074] (2) 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 (W O / W I ) is between 0.5 and 1.3 The adhesive sheet described in (1) above.

[0075] With this configuration, the adhesive sheet can exhibit even greater adhesiveness over a wide temperature range, from low to high temperatures.

[0076] (3) The adhesive layer further comprises a thermoplastic elastomer as the organic component. The adhesive sheet described in (1) or (2) above.

[0077] With this configuration, the adhesive sheet can exhibit even greater adhesiveness over a wide temperature range from low to high temperatures.

[0078] (4) The thermoplastic elastomer is at least one of a styrene-based thermoplastic elastomer and an acrylic-based thermoplastic elastomer. The adhesive sheet described in (3) above.

[0079] With this configuration, the adhesive sheet can exhibit even greater adhesiveness over a wide temperature range from low to high temperatures.

[0080] (5) The styrene-based thermoplastic elastomer has a diblock rate of 10% to 70%. The adhesive sheet described in (4) above.

[0081] With this configuration, the adhesive sheet can exhibit even greater adhesiveness over a wide temperature range from low to high temperatures.

[0082] (6) The aforementioned inorganic component includes an inorganic filler. The adhesive sheet described in any of (2) to (4) above.

[0083] With this configuration, the inclusion of the inorganic filler makes it easier to ensure the thickness of the adhesive sheet.

[0084] (7) The content of the inorganic filler in the adhesive layer is 20% by mass or more. The adhesive sheet described in (6) above.

[0085] With this configuration, it becomes easier to ensure a sufficient thickness for the adhesive sheet.

[0086] (8) The adhesive layer further comprises a tackifier as the organic component. The adhesive sheet described in any of (1) through (7) above.

[0087] With this configuration, the adhesive sheet can exhibit even greater adhesive strength over a wide temperature range, from low to high temperatures.

[0088] (9) 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 (8) above.

[0089] 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, among the sheets included in the above group, plastic sheets and metal sheets generally have high tensile strength. Therefore, by constructing the base material from these sheets, the waterproofness and durability of the adhesive sheet can be improved. Furthermore, among the sheets included in the above group, fiber sheets, rubber sheets, and foam sheets generally have high flexibility. Therefore, by constructing the substrate from these sheets, it is possible to adequately conform to adherends that have irregularities on their surface.

[0090] (10) The aforementioned fiber sheet is a nonwoven fabric sheet or a woven fabric sheet. The adhesive sheet described in (9) above.

[0091] 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.

[0092] Furthermore, the adhesive sheet according to the present invention is not limited to the embodiments described above. Nor is it limited by the effects and benefits described above. The adhesive sheet according to the present invention can be modified in various ways without departing from the spirit of the invention. [Examples]

[0093] 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.

[0094] 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) • Recycled butyl rubber: Recycled butyl S (manufactured by Kengomu Kogyo Co., Ltd., mass-average molecular weight 200,000) (b) Polyisobutylene (PIB) Opanol N100 (manufactured by BASF Japan, mass-average molecular weight 1.3 million) (c) Thermoplastic elastomer • Styrene-isoprene-styrene copolymer (SIS) SIS1: Styrene content 24% by mass, diblock rate 67% SIS2: Styrene content 16% by mass, diblock rate 56% SIS3: Styrene content 14% by mass, diblock rate 26% SIS4: Styrene content 16% by mass, diblock rate 12% Styrene isobutylene styrene (SIBS) SIBS1: Styrene content 20% by mass, diblock content 41% SIBS2: Styrene content 20% by mass, diblock content 46% Acrylic rubber Butyl acrylate (BA):acrylic acid (AA) = 98:2, mass-average molecular weight 1,000,000 (2) Tackifier Tackifier 1: TREZ RC093 (manufactured by Nippon Petrochemical Co., Ltd., C5 hydrocarbon, mass-average molecular weight 1440, softening point 94°C) Tackifier 2: TREZ RB100 (manufactured by Nippon Petrochemical Co., Ltd., C5 hydrocarbon, mass-average molecular weight 3090, softening point 98°C) (3) Softener (a) Polyisobutylene (PIB) Polyisobutylene 1:Tetrax 5T (manufactured by Nippon Petrochemical Co., Ltd., mass-average molecular weight 50,000) Polyisobutylene 2:HV-300 (manufactured by Nippon Petrochemical Co., Ltd., number average molecular weight 1400, kinematic viscosity at 40°C 26000 mmHg) 2 / s) Polyisobutylene 3:HV-15 (manufactured by Nippon Petrochemical Co., Ltd., number average molecular weight 630, kinematic viscosity at 40°C 655 mmHg) 2 / s) (b) Ethylene-α-olefin co-oligomer Lucant LX-400 (manufactured by Mitsui Chemicals, mass-average molecular weight 12000, kinematic viscosity at 40°C 38000 mmHg) 2 / s) (4) Inorganic fillers Heavy calcium carbonate (manufactured by Maruo Calcium Co., Ltd., sieve residue (350 mesh) 0.5% or less (compliant with JIS K5101)) (5) Colorants Carbon: Seast 3H (manufactured by Tokai Carbon Co., Ltd., carbon black) (6) Anti-aging agents Phenolic antioxidant: Songnox 1010 (manufactured by SONGWON) Phosphorus-based anti-aging agent: Irgafos168 (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.

[0095] The adhesive compositions for Examples 1 to 10 and Comparative Examples 1 to 3 were obtained by blending rubber components (butyl rubber, polyisobutylene rubber, and thermoplastic elastomer), tackifiers, softeners, inorganic fillers, colorants, and antioxidants in the proportions (parts by mass) shown in Table 1 below, while heating.

[0096] 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.

[0097] [Table 1]

[0098] [Storage modulus] Adhesive sheets for each example Adhesive layer The storage modulus G1' at 60°C and the storage modulus G2' 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').

[0099] [Adhesive strength] Adhesive sheets for each example Adhesive layer The adhesive strength 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.

[0100] [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), adhesion stability tests were conducted on the adhesive sheets for each example, 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 of the adhesion stability test are shown in Table 2 below.

[0101] [Level of contamination] When the adhesive sheet for each example was applied to the object to be adhered to, the extent to which the object was contaminated by the adhesive layer of the adhesive sheet (the coated object of the adhesive composition) was evaluated. In the following, the degree of contamination of the object to be coated will be referred to as the "degree of contamination." The "level of contamination" was evaluated according to the following procedure. (1) A 50mm wide cotton cloth (Kinkin No. 3) is placed on neutral, high-quality paper (PLUS Corporation, product name "Smart Value A040J Copy Paper High White"), and the whiteness L of the cotton cloth is measured using a multi-angle spectroscopic colorimeter (MA68II, X-rite Corporation). * Measure 0. The measurement angle for the multi-angle spectroscopic colorimeter is set at 15°. (2) Fix the adhesive sheet for each example to the support under room temperature (23±2℃) conditions. For each example, a 50mm wide adhesive sheet will be used. Furthermore, the adhesive sheet according to each example is fixed to the support by bringing the base material into contact with the support. That is, the adhesive sheet according to each example is fixed to the support with the adhesive layer exposed. (3) For each example of the adhesive sheet fixed to the support, a 50 mm wide cotton cloth (No. 3) is pressed onto the adhesive layer. The cotton cloth is pressed onto the adhesive layer by placing the cotton cloth on the adhesive layer and then passing a 2kg pressure roller back and forth once. (4) With respect to each example of the adhesive sheet fixed to the support, the cotton cloth is pressed onto the adhesive layer and then peeled off from the adhesive layer after 1 minute has elapsed. The cotton cloth is peeled from the adhesive layer under conditions of a peeling angle of 90° and a tensile speed of 100 mm / min. (5) Using a multi-angle spectroscopic colorimeter (MA68II, manufactured by X-rite), the whiteness L of the cotton cloth peeled off from the adhesive layer was measured. * Measure 1. Whiteness L * Measurement 1 is whiteness L * It is carried out in the same way as 0. (6) Whiteness L * 1 and whiteness L * ΔL is the difference from 0. * (L * 1-L * Calculate (0) and evaluate the degree of contamination based on the following evaluation criteria. • Good: ΔL * is 5 or less ·Defect:ΔL * is greater than 5 The results of the pollution level assessment are shown in Table 2 below. Furthermore, Table 2 below shows ΔL * The calculation results are also shown.

[0102] [Table 2]

[0103] Table 2 shows that the adhesive sheets according to Examples 1 to 10 exhibit excellent adhesive properties over a wide range of temperatures, from low temperatures (-10°C) to high temperatures (60°C). In contrast, the adhesive sheets according to Comparative Examples 1 to 3 showed inferior adhesiveness at at least one of low and high temperatures. Furthermore, it was found that the adhesive sheets in Examples 1 to 10 all exhibited excellent adhesion stability at 60°C. From this, it was found that the adhesive sheets according to Examples 1 to 10 can exhibit excellent retention properties on the object to be adhered to at 60°C. Furthermore, it was found that the adhesive sheets according to Examples 1 to 10 were evaluated as "good" in terms of the degree of contamination of the cotton cloth to be adhered, meaning that the degree of contamination of the cotton cloth was small, whereas the adhesive sheets according to Comparative Examples 1 and 2 were evaluated as "poor" in terms of the degree of contamination of the cotton cloth, meaning that the degree of contamination of the cotton cloth was large. Furthermore, regarding the adhesive sheet related to Comparative Example 2, ΔL * The particularly high value is presumed to be because the adhesive layer of the adhesive sheet in Comparative Example 2 contains recycled butyl rubber as butyl rubber (see Table 1). More specifically, recycled butyl rubber is generally obtained by extracting butyl rubber components from rubber products such as tires. However, the recycled butyl rubber contained in the adhesive layer of the adhesive sheet in Comparative Example 2 was obtained from a rubber product containing a large amount of carbon black (for example, about 30% by mass), therefore, ΔL * It is presumed that the value of was particularly high. [Explanation of symbols]

[0104] 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, thermoplastic elastomer, and a softening agent as organic components. The softening agent comprises at least one of polyisobutylene and ethylene-α-olefin co-oligomer. The aforementioned adhesive layer contains an inorganic filler as an inorganic component, 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 11 or less, The storage modulus of the adhesive layer at -10°C is G. ２ ' is 0.7 MPa or less, The adhesive strength of the adhesive layer at -10°C is 3.0 N / 25 mm or more. Adhesive sheet.

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

3. The thermoplastic elastomer comprises at least one of an acrylic thermoplastic elastomer and a styrene thermoplastic elastomer. The adhesive sheet according to claim 1 or 2.

4. The thermoplastic elastomer comprises at least one of the following: acrylic rubber as the acrylic thermoplastic elastomer, or styrene-isoprene-styrene block copolymer or styrene-isobutylene-styrene block copolymer as the styrene thermoplastic elastomer. The adhesive sheet according to claim 3.

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

6. 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.

7. The adhesive layer further comprises a tackifier as the organic component. The adhesive sheet according to claim 1 or 2.

8. 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.

9. The aforementioned fiber sheet is a nonwoven fabric sheet or a woven fabric sheet. The adhesive sheet according to claim 8.

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