Adhesive components

Abstract

The object of the present invention is to provide an adhesive composition that has sufficient tackiness and excellent low-temperature flexibility and bleed resistance. [Solution] The present invention provides an adhesive composition containing a terminal hydroxyethylene-α-olefin copolymer (Z) having a constituent unit (i) derived from ethylene and a constituent unit (ii) derived from an α-olefin having 3 to 10 carbon atoms, and satisfying the following requirements (Z1) and (Z2), a (meth)acrylic resin (B), and a crosslinking agent (C). (Z1) 1 Excluding saturated ends determined by 1H-NMR, more than 60% of all ends contain a hydroxyl group. (Z2) The melting point measured by differential scanning calorimetry (DSC) is not observed.

Description

Technical Field

[0001] The present invention relates to an adhesive composition having sufficient adhesiveness, excellent low-temperature flexibility and bleed resistance, a method for producing the same, and an adhesive sheet having an adhesive layer formed from the adhesive composition.

Background Art

[0002] In recent years, sealing of electronic devices such as organic EL devices, solar cells, and sensor devices, image display devices such as liquid crystal displays, and input / output devices such as touch panels used in combination with image display devices have been widely used. In the production of these, an adhesive composition and an adhesive sheet having an adhesive layer formed from the adhesive composition are often used.

[0003] The application of touch panels to automobiles has also been expanding. In automobile applications, due to reasons such as high temperatures in summer, higher high-temperature and high-humidity durability than general applications is required. For example, Patent Document 1 discloses an adhesive composition having excellent performance even under high-temperature and high-humidity conditions, which contains a specific (meth)acrylic copolymer, an olefin polymer having a specific viscosity, and a crosslinking agent, and also discloses an adhesive sheet having an adhesive layer formed from such an adhesive composition.

[0004] In recent years, for electronic components such as those constituting image display devices and input / output devices, a printed portion may be provided at the peripheral portion in order to impart design properties. When bonding such a printed surface with an adhesive sheet, flexibility for following steps is required. For example, Patent Document 2 discloses an adhesive composition having excellent flexibility performance, which contains two types of methacrylic acid alkyl ester monomers having different carbon numbers in the alkyl group, a crosslinking agent, and a plasticizer.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] International Publication No. 2019 / 013130 Pamphlet [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-105329 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] However, in conventional adhesive compositions, there has been room for improvement from the viewpoints of flexibility in a low-temperature environment and compatibility between adhesive strength and bleed resistance. For example, an adhesive composition containing a (meth)acrylic copolymer, an unmodified olefin polymer, and a crosslinking agent tends to have insufficient bleed resistance, and there is room for improvement from the viewpoint of compatibility between adhesive strength and bleed resistance.

[0007] An object of the present invention is to provide an adhesive composition having sufficient adhesiveness and excellent low-temperature flexibility and bleed resistance. [Means for Solving the Problems]

[0008] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by adopting a specific terminal hydroxyethylene-α-olefin copolymer as the olefin polymer in an adhesive composition containing a (meth)acrylic copolymer, an olefin polymer, and a crosslinking agent, and have completed the present invention.

[0009] The present invention provides the following. [1] A terminal hydroxyethylene-α-olefin copolymer (Z) having a structural unit (i) derived from ethylene and a structural unit (ii) derived from an α-olefin having 3 to 10 carbon atoms and satisfying the following requirements (Z1) and (Z2), an adhesive composition containing a (meth)acrylic resin (B) and a crosslinking agent (C); (Z1) 1Excluding saturated ends determined by 1H-NMR, more than 60% of all ends contain hydroxyl groups; (Z2) The melting point measured by differential scanning calorimetry (DSC) is not observed.

[0010] [2] The adhesive composition according to [1] above, wherein the terminal hydroxyethylene-α-olefin copolymer (Z) further satisfies the following requirement (Z3); (Z3) 1 Excluding saturated ends determined by 1H-NMR, more than 60% of all ends contain two or more hydroxyl groups.

[0011] [3] The adhesive composition according to either [1] or [2] above, wherein the (meth)acrylic resin (B) satisfies the following (B1) and (B2); (B1) Contains a structural unit derived from a (meth)acrylate having an alkyl group with 1 to 12 carbon atoms, and a structural unit derived from a (meth)acrylate containing a hydroxyl group; (B2) The peak temperature of the loss tangent (tanδ) due to the glass transition temperature, measured by the temperature dependence of dynamic viscoelasticity (frequency 1 Hz, -100 to 200°C), is less than 0°C.

[0012] [4] The adhesive composition according to any one of [1] to [3] above, wherein the terminal hydroxyethylene-α-olefin copolymer (Z) further satisfies the following requirements (Z4) to (Z6); (Z4) With respect to a total of 100 mol% of the content of constituent unit (i) and constituent unit (ii), the content of constituent unit (i) is 30 to 70 mol%, and the content of constituent unit (ii) is 30 to 70 mol%; (Z5) The number-average molecular weight (Mn) obtained by gel permeation chromatography (GPC) and converted to polystyrene equivalent is 300 to 10000; It is measured by gel permeation chromatography (GPC), and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) obtained in terms of polystyrene is 1.0 to 5.0.

[0013] [5] The adhesive composition according to any one of [1] to [4], wherein the terminal hydroxyethylene·α-olefin copolymer (Z) further satisfies the following requirement (Z7). (Z7) 1 60% or more of all the terminals excluding the saturated terminals determined by 1H-NMR are terminals containing at least the following general formula (1). ―N(-R 1 -OH)(-R 2 -OH) General formula (1) <7000141>(In the formula, R 1 , R 2 is a divalent organic group having 1 to 6 carbon atoms.)

[0014] [6] The adhesive composition according to any one of [1] to [4], wherein the terminal hydroxyethylene·α-olefin copolymer (Z) further satisfies the following requirement (Z8); (Z8) 1 60% or more of all the terminals excluding the saturated terminals determined by 1H-NMR are terminals containing at least the following general formula (2). -S-CH2-R 3 General formula (2) (In the formula, R 3 is an organic group having 2 to 5 hydroxy groups.)

[0015] [7] When the total of the content of the terminal hydroxyethylene·α-olefin copolymer (Z), the content of the (meth)acrylic resin (B), and the content of the crosslinking agent (C) is 100% by mass, the amount of the terminal hydroxyethylene·α-olefin copolymer (Z) is 0.5% by mass or more and 50% by mass or less, the amount of the (meth)acrylic resin (B) is 47% by mass or more and 99% by mass, The adhesive composition according to any one of [1] to [6], wherein the amount of the crosslinking agent (C) is 0.5% by mass or more and 5% by mass or less.

[0016] [8] An adhesive sheet having an adhesive layer formed from any of the adhesive compositions described in [1] to [7].

[0017] [9] A terminal hydroxyethylene-α-olefin copolymer (Z) is produced by reacting an ethylene-α-olefin copolymer (A), which has a constituent unit (i) derived from ethylene and a constituent unit (ii) derived from an α-olefin having 3 to 10 carbon atoms, with a hydroxyl group-containing compound, and satisfies the following requirements (Z1) and (Z2), (Meth)acrylic resin (B) and A method for producing an adhesive composition, comprising the step of mixing with a crosslinking agent (C); (Z1) 1 Excluding saturated ends determined by 1H-NMR, more than 60% of all ends contain hydroxyl groups; (Z2) The melting point measured by differential scanning calorimetry (DSC) is not observed.

[0018]

[10] The manufacturing method described in [9] above, wherein the ethylene-α-olefin copolymer (A) satisfies the following requirements (A1) to (A3); (A1) The content of component (i) is 30 to 70 mol% and the content of component (ii) is 30 to 70 mol% with respect to a total of 100 mol% of the content of component (i) and component (ii); (A2) The number-average molecular weight (Mn) obtained by gel permeation chromatography (GPC) and converted to polystyrene equivalent is 300 to 5,000; (A3) 1The total integrated intensity of the signals of vinyl group terminals, vinylidene group terminals, 2-substituted olefin terminals, and 3-substituted olefin terminals determined by 1H-NMR reaches over 70% with respect to 100% of the total integrated intensity. [Advantages of the Invention]

[0019] According to the present invention, it is possible to provide a pressure-sensitive adhesive composition having sufficient adhesiveness, excellent low-temperature flexibility and bleed resistance, and a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. [Modes for Carrying Out the Invention]

[0020] Hereinafter, the present invention will be described in more detail. In the present invention, "room temperature" means 25°C. In this specification, "~" indicating a numerical range is used to mean a range including the numerical values described before and after it as the lower limit value and the upper limit value. In this specification, when "~" indicating a numerical range is used, for example, when expressed as "M~N" (M and N are numerical values satisfying M < N), unless otherwise specified, it means "M or more and N or less". Also, the unit described after either one of the numerical values before and after "~" is the unit of both the numerical values described before and after "~" unless otherwise specified. Further, when numerical ranges are described stepwise, the upper limit and the lower limit of each numerical range can be arbitrarily combined. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment. In this specification, unless otherwise particularly limited, each component in the composition, or each structural unit in a polymer (polymer) such as a copolymer, may be included alone or in combination of two or more.

[0021] [Pressure-Sensitive Adhesive Composition] The pressure-sensitive adhesive composition according to the present invention contains a terminal hydroxyethylene-α-olefin copolymer (Z) satisfying specific requirements, a (meth)acrylic resin (B), and a crosslinking agent (C). In this specification, "(meth)acrylic" means acrylic or methacrylic, "(meth)acrylate" means acrylate or methacrylate, and "(co)polymer" means homopolymer or copolymer.

[0022] [Terminal hydroxyethylene-α-olefin copolymer (Z)] A terminal hydroxyethylene-α-olefin copolymer (Z) is a copolymer having a constituent unit (i) derived from ethylene and a constituent unit (ii) derived from an α-olefin having 3 to 10 carbon atoms, and satisfying the following requirements (Z1) and (Z2). (Z1) 1 Excluding saturated ends determined by 1H-NMR, more than 60% of all ends contain a hydroxyl group. (Z2) The melting point measured by differential scanning calorimetry (DSC) is not observed.

[0023] Examples of α-olefins having 3 to 10 carbon atoms in constituent unit (ii) include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and 1-decene, with α-olefins having 3 to 8 carbon atoms being preferred, more preferably α-olefins having 3 to 5 carbon atoms, and even more preferably propylene.

[0024] Here, the terminal hydroxyethylene-α-olefin copolymer (Z) preferably satisfies one or more of the following requirements (Z3) to (Z6), in addition to the above requirements (Z1) and (Z2), more preferably two or more, and even more preferably all of them. In addition, it is further preferable that it satisfies either the following requirement (Z7) or (Z8). (Z3) 1 Excluding saturated ends determined by 1H-NMR, more than 60% of all ends contain two or more hydroxyl groups. (Z4) With respect to a total of 100 mol% of the content of constituent unit (i) and constituent unit (ii), the content of constituent unit (i) is 30 to 70 mol%, and the content of constituent unit (ii) is 30 to 70 mol%; (Z5) The number-average molecular weight (Mn) obtained by gel permeation chromatography (GPC) and converted to polystyrene equivalent is 300 to 10000; (Z6) The ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) obtained by gel permeation chromatography (GPC) and converted to polystyrene equivalent (Mw / Mn) is between 1.0 and 5.0. (Z7) 1 At least 60% of all ends, excluding the saturated ends determined by 1H-NMR, must contain at least the following general formula (1). ―N(-R 1 -OH)(-R 2 -OH) General formula (1) (In the formula, R 1 , R 2 (It is a divalent organic group with 1 to 6 carbon atoms.) (Z8) 1 At least 60% of all terminals, excluding saturated terminals determined by 1H-NMR, contain at least the following general formula (2). -S-CH2-R 3 General formula (2) (In the formula, R 3 (A hydroxyl group is an organic group that has 2 to 5 hydroxyl groups.)

[0025] Regarding requirement (Z1) In the present invention, the terminal containing a hydroxyl group is selected from among all the terminals of the terminal hydroxyethylene-α-olefin copolymer (Z), 1 The remaining ends after removing the saturated ends determined by 1H-NMR account for 60% or more of the total (content of 60% or more) (Requirement (Z1)). Preferably, they account for 62% or more, and more preferably 65% ​​or more. The upper limit is preferably 100%, more preferably 95%, and even more preferably 90%.

[0026] Regarding requirement (Z2) The terminal hydroxyethylene-α-olefin copolymer (Z) of the present invention does not exhibit a melting point as measured by differential scanning calorimetry (DSC). Here, "not observing the melting point (Tm)" means that the heat of fusion (ΔH) (unit: J / g) measured by differential scanning calorimetry (DSC) is not substantially measured. "Not substantially measuring the heat of fusion (ΔH)" means that no peak is observed in the differential scanning calorimetry (DSC) measurement, or the observed heat of fusion is 1 J / g or less.

[0027] The terminal hydroxyethylene-α-olefin copolymer (Z) of the present invention is preferably a copolymer that satisfies not only requirements (Z1) and (Z2) but also one or more of requirements (Z3) to (Z6), more preferably satisfies at least two, and even more preferably satisfies at least three. Furthermore, a copolymer that satisfies requirement (Z7) or requirement (Z8) is preferred. Requirements (Z3) through (Z8) are described below.

[0028] Regarding requirement (Z3) The terminal hydroxyethylene-α-olefin copolymer (Z) of the present invention preferably has a terminal containing two or more hydroxyl groups. The terminals containing two or more hydroxyl groups account for 60% or more of the total terminals of the terminal hydroxyethylene-α-olefin copolymer (Z) after excluding the saturated terminal determined by 1H-NMR (Requirement (Z3)). Of these, it is preferable that they account for 62% or more, and more preferably 65% ​​or more. The upper limit is preferably 100%, more preferably 95%, and even more preferably 90%.

[0029] Regarding the requirements (Z4) The content of constituent units (i) and (ii) in the terminal hydroxyethylene-α-olefin copolymer (Z) of the present invention is arbitrary. Among these, it is preferable that the content of constituent unit (i) be 30 to 70 mol% (Requirement (Z4)), more preferably 35 to 65 mol%, more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%, based on a total of 100 mol% of these constituent units, and that the content of constituent unit (ii) be 30 to 70 mol% (Requirement (Z4)), more preferably 35 to 65 mol%, more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. The combination of the lower and upper limits of the content of constituent unit (i) and constituent unit (ii) is arbitrary.

[0030] Regarding the requirement (Z5) The terminal hydroxyethylene-α-olefin copolymer (Z) is measured by gel permeation chromatography (GPC), and the number-average molecular weight (Mn) obtained in polystyrene terms is preferably 300 to 10,000 (requirement (Z5)), more preferably 400 to 8,000, and more preferably 500 to 7,000. The combination of the lower and upper limits of the number-average molecular weight (Mn) is arbitrary.

[0031] Regarding requirement (Z6) The terminal hydroxyethylene-α-olefin copolymer (Z) is measured by gel permeation chromatography (GPC), and the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) obtained on a polystyrene basis (Mw / Mn) is preferably 1.5 to 5.0 (requirement (Z6)), more preferably 1.55 to 4.7, more preferably 1.57 to 4.5, and among these, 1.60 to 4.3 is preferred. (Mw / Mn) can be determined by the method described in the examples. Note that the combination of the lower and upper limits for Mw / Mn is arbitrary.

[0032] Regarding requirement (Z7) Preferably, the terminal of the terminal hydroxyethylene-α-olefin copolymer (Z) contains two or more hydroxyl groups, and includes at least the following general formula (1) (Requirement (Z7)). -N(-R 1 -OH)(-R 2 -OH) General formula (1) (In the formula, R 1 , R 2 (It is a divalent organic group with 1 to 6 carbon atoms.)

[0033] In the general formula (1) above, R 1 , R 2 These are divalent organic groups with 1 to 6 carbon atoms, such as alkylene groups like methylene (-CH2-), ethylene (-CH2CH2-), and propylene (-CH2CH(-CH3)-).

[0034] An example of general formula (1) is the following: -N(-CH2OH)2 -N(-CH2CH2OH)2 -N [-CH2CH(-CH3)OH]2 Furthermore, examples of terminals that include general formula (1) are as follows: -CH(-OH)-CH2-N(-CH2CH2OH)2 -C(-CH3)(-OH)-CH2-N(-CH2CH2OH)2

[0035] Regarding requirement (Z8) Furthermore, other preferred embodiments of such terminals include, 1 In some cases, more than 60% of all ends, excluding the saturated ends determined by 1H-NMR, contain at least the following general formula (2). -S-CH2-R 3 General formula (2) (In the formula, R 3 (It is an organic group that has 2 to 5 hydroxyl groups.)

[0036] An example of general formula (2) is the following: -S-CH2-CH(-OH)-CH2OH -S-CH2-CH(-CH2OH)-CH2CH2OH -S-CH2-CH(-OH)-CH2-O-CH2-CH(-OH)-CH2OH Furthermore, examples of terminals that include general formula (2) are as follows: -CH2-CH2-S-CH2-CH(-OH)-CH2OH -CH(-CH3)-CH2-S-CH2-CH(-OH)-CH2OH

[0037] Ends containing hydroxyl groups, including general formula (1) and general formula (2), are selected from all the ends of the terminal hydroxyethylene-α-olefin copolymer (Z). 1 It accounts for 60% or more of the total ends after removing the saturated ends determined by 1H-NMR (Requirement (Z1)). Preferably, it accounts for 65% or more of these ends. The upper limit is preferably 100%, more preferably 95%, and even more preferably 90%.

[0038] Method for producing terminal hydroxyethylene-α-olefin copolymer (Z) The terminal hydroxyethylene-α-olefin copolymer (Z) of the present invention is produced by introducing a terminal containing one or more hydroxyl groups to the terminal of an ethylene-α-olefin copolymer (A) having structural units (i) and (ii). A preferred method involves converting either or both of the vinyl group ends and vinylidene group ends of an ethylene-α-olefin copolymer (A) into epoxy-containing groups, and then reacting these epoxy-containing groups with a low-molecular-weight compound having one or more hydroxyl groups.

[0039] The raw material is ethylene-α-olefin copolymer (A) The method for producing the ethylene-α-olefin copolymer (A) is not particularly limited, but for example, it can be produced by copolymerizing ethylene with at least one α-olefin having 3 to 10 carbon atoms in the presence of an olefin polymerization catalyst. Preferably, the method includes a step of polymerizing the olefin at a temperature of 20 to 130°C in the presence of an activator and at least one metallocene compound.

[0040] The polymerization temperature is preferably 25 to 130°C, more preferably 25 to 125°C, and more preferably 25 to 120°C. A polymerization temperature within this range is preferable because it allows the molecular weight of the resulting polymer to be controlled within the range specified in requirement (A2). Examples of activators include at least one compound (b) selected from organometallic compounds (b-1), organoaluminum oxy compounds (b-2), and compounds that react with metallocene compounds to form ion pairs (b-3).

[0041] Examples of organometallic compounds (b-1) (excluding organoaluminum oxy compounds (b-2)) include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, and tri-n-octylaluminum, as well as organoaluminum compounds such as tricycloalkylaluminum, isobutylaluminum dichloride, diethylaluminum chloride, ethylaluminum dichloride, ethylaluminum sesquichloride, methylaluminum dichloride, dimethylaluminum chloride, and diisobutylaluminum hydride.

[0042] Examples of organoaluminum oxy compounds (b-2) include conventionally known aluminoxanes.

[0043] Examples of compounds (b-3) that react with metallocene compounds to form ion pairs include Lewis acids, ionic compounds, borane compounds, and carborane compounds described in Japanese Patent Publication No. 1-501950, Japanese Patent Publication No. 1-502036, Japanese Patent Publication No. 3-179005, Japanese Patent Publication No. 3-179006, Japanese Patent Publication No. 3-207703, Japanese Patent Publication No. 3-207704, U.S. Patent No. 5321106, International Publication No. 2015 / 122415, etc.

[0044] The polymerization pressure is typically atmospheric pressure to 10 MPa gauge pressure, preferably atmospheric pressure to 8 MPa gauge pressure, and copolymerization can be carried out by batch, semi-continuous, or continuous methods. The reaction time (or average residence time if the copolymerization reaction is carried out continuously) varies depending on conditions such as catalyst concentration and polymerization temperature, and can be selected as appropriate, but is usually 1 minute to 3 hours, preferably 5 minutes to 2.5 hours. Furthermore, polymerization can be carried out in two or more stages with different reaction conditions.

[0045] The molecular weight of the resulting ethylene-α-olefin copolymer (A) can also be adjusted by changing the hydrogen concentration in the polymerization system and the polymerization temperature. It can also be adjusted by the amount of catalyst component used. When hydrogen is added to the polymerization system, an appropriate amount is approximately 0.001 to 5,000 NL per 1 kg of the resulting ethylene-α-olefin copolymer. The amount of terminal unsaturation in the resulting ethylene-α-olefin copolymer (A) can be increased by minimizing the amount of hydrogenation.

[0046] The raw material ethylene-α-olefin copolymer (A) may contain biomass-derived monomers (ethylene, α-olefin). The monomers constituting the polymer may consist solely of biomass-derived monomers, or it may contain both biomass-derived monomers and fossil fuel-derived monomers. Biomass-derived monomers are monomers derived from any renewable natural raw materials and their residues, including fungi, yeasts, algae, and bacteria, which are plant-derived or animal-derived, and which contain 10¹⁴C isotopes as carbon. -12 It contains a certain proportion, and the biomass carbon concentration (pMC) measured according to ASTM D 6866 is approximately 100 pMC. Biomass-derived monomers are obtained by conventionally known methods.

[0047] The raw material ethylene-α-olefin copolymer (A) may contain monomers derived from chemical recycling (ethylene, α-olefin). The monomers constituting the polymer may consist solely of monomers derived from chemical recycling, or they may contain monomers derived from chemical recycling, monomers derived from fossil fuels, and / or monomers derived from biomass. Monomers derived from chemical recycling can be obtained by conventionally known methods.

[0048] The raw material, ethylene-α-olefin copolymer (A), is not particularly limited, but those that satisfy the following requirements (A1) to (A3) are preferred. (A1) With respect to a total of 100 mol% of the content of constituent unit (i) and constituent unit (ii), the content of constituent unit (i) is 30 to 70 mol%, and the content of constituent unit (ii) is 30 to 70 mol%. Preferably, the content of constituent unit (i) is 35 to 65 mol%, more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%, and preferably the content of constituent unit (ii) is 35 to 65 mol%, more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. Constituent unit (ii) is preferably an α-olefin having 3 to 8 carbon atoms, more preferably an α-olefin having 3 to 5 carbon atoms, and even more preferably propylene. The combination of the lower and upper limits of the content of constituent unit (i) and constituent unit (ii) is arbitrary. (A2) The number-average molecular weight (Mn) obtained by gel permeation chromatography (GPC) and converted to polystyrene equivalent is 300 to 10,000, preferably 400 to 8,000, and more preferably 500 to 7,000. The combination of the lower and upper limits of the number-average molecular weight (Mn) is arbitrary. (A3) 1 The sum of the integrated intensities of the vinyl group endpoint and vinylidene group endpoint is greater than 70%, preferably greater than 75%, and more preferably greater than 80%, relative to 100% of the sum of the integrated intensities of the vinyl group endpoint, vinylidene group endpoint, disubstituted olefin endpoint, and trisubstituted olefin endpoint as determined by 1H-NMR. The upper limit is 100%, preferably 99%, and more preferably 98%.

[0049] In other words, the raw material, ethylene-α-olefin copolymer (A), has saturated and unsaturated ends, and the unsaturated ends include vinyl group ends, vinylidene group ends, disubstituted olefin ends, and trisubstituted olefin ends. Of these unsaturated ends, vinyl group ends and vinylidene group ends account for more than 70% of the total unsaturated ends (calculation is 1If an ethylene-α-olefin copolymer (A) (as determined by 1H-NMR) is used as a raw material, it is preferable to introduce terminals containing hydroxyl groups at both or either the vinyl group terminal and the vinylidene group terminal. As a result, if the reaction proceeds quantitatively, it is possible to introduce terminals containing hydroxyl groups at more than 70% of all terminals excluding the saturated terminal.

[0050] Method for epoxidizing vinyl and vinylidene group ends The method for converting the vinyl groups at the ends of the ethylene-α-olefin copolymer (A), and even unsaturated groups such as vinylidene groups, to epoxy-containing groups is not particularly limited, but the following methods can be given as examples. (1) Oxidation by peracids such as performic acid, peracetic acid, and perbenzoic acid (2) Oxidation with titanosilicate and hydrogen peroxide (3) Oxidation with rhenium oxide catalyst such as methyltrioxorhenium and hydrogen peroxide (4) Oxidation with a porphyrin complex catalyst such as manganese porphyrin or iron porphyrin and hydrogen peroxide or hypochlorite (5) Oxidation with Salen complex such as manganese Salen and hydrogen peroxide or hypochlorite (6) Oxidation with manganese-triazacyclononane (TACN) complex and other TACN complexes and hydrogen peroxide (7) Oxidation by hydrogen peroxide in the presence of a group VI transition metal catalyst such as a tungsten compound and a phase transfer catalyst. Of the methods (1) to (7) described above, methods (1) and (7) are particularly preferred in terms of activity.

[0051] In the oxidation by peracid described in (1) above, it is preferable to use bis(monoperoxyphthalate)magnesium hexahydrate (MMPP) and / or m-chloroperbenzoic acid (mCPBA) as the peracid.

[0052] Method for introducing a hydroxyl group-containing terminus to an epoxy-containing group To introduce a hydroxyl group-containing end to the ethylene-α-olefin copolymer having an epoxy group at its end, as described above, one method is to react the epoxy group with a low-molecular-weight compound having a hydroxyl group. The terminal hydroxyethylene-α-olefin copolymer (Z) used in the present invention preferably has a terminal containing two or more hydroxyl groups. One method for obtaining such copolymers is, for example, if the terminal hydroxyethylene-α-olefin copolymer (Z) has a terminal containing two hydroxyl groups, to react an ethylene-α-olefin copolymer having an epoxy group at the terminal with a low molecular weight compound having two hydroxyl groups. Suitable low-molecular-weight compounds having two hydroxyl groups in one molecule include secondary amines having two hydroxyl groups in one molecule. Low-molecular-weight compounds having hydroxyl groups may be derived from biomass.

[0053] As a secondary amine having two hydroxyl groups in one molecule, the compound represented by the following general formula (3) is preferred. HN(-R 1 -OH)(-R 2 -OH) General formula (3) (In the formula, R 1 , R 2 These are R in the general formula (1) above. 1 , R 2 It is similar to this. Examples of compounds represented by general formula (3) include dimethanolamine, diethanolamine, di(n-propanol)amine, diisopropanolamine, dibutanolamine, dipentanolamine, and dihexanolamine, which may be used individually or in combination of two or more.

[0054] Method of hydroxylation by thiolene reaction of vinyl and vinylidene group termini As a thiol compound having two or more hydroxyl groups in one molecule, the compound represented by the following general formula (4) is preferred. HS-R 3 General formula (4) (In the formula, R3 R in the general formula (2) above is 3 It is similar to this. Examples of thiol compounds represented by general formula (4) include the following: 1-Thioglycerol [HS-CH2-CH(-OH)-CH2(-OH)] 1-Thiodiglycerol [HS-CH2-CH(-OH)-CH2-O-CH2-CH(-OH)-CH2OH]

[0055] When using the thiol compound represented by general formula (4), it is obtained by reacting the starting material, ethylene-α-olefin copolymer (A), in the presence of a radical generator. The radical initiator is not particularly limited as long as it has the function of a thermal radical initiator or a photoradical initiator, but examples include the azo compound azobisisobutyronitrile (AIBN), the organic peroxide benzoyl peroxide, Kayaren 6 (manufactured by Kayaku Akzo Co., Ltd.), Perhexa 25B (registered trademark, manufactured by Nippon Oil & Fats Co., Ltd.), the benzophenone-based photoradical initiator benzophenone, orthobenzoylmethyl benzoate, 4-benzoyl-4'-methyldiphenyl sulfide, the acetophenone-based photopolymerization initiator acetophenone, benzyldimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and the benzoin ether-based photoradical initiator benzoin isobutyl ether, etc.

[0056] The amount of radical initiator used is preferably 0.0001 to 10 molar times, more preferably 0.0001 to 5 molar times, and most preferably 0.0001 to 1 molar time, relative to the ethylene-α-olefin copolymer (A). These radical initiators may be used individually or in combination of two or more.

[0057] The reaction between the ethylene-α-olefin copolymer (A) and the thiol compound can be carried out in the absence of a solvent or in the presence of a solvent. The solvent used is not particularly limited, but examples include aliphatic hydrocarbons such as n-hexane, alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene and xylene, esters such as ethyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, and methyl propyl ketone, ethers such as tetrahydrofuran and 1,4-dioxane, and halogenated hydrocarbons such as chloroform, dichloroethane, trichloroethane, and perchloroethane. Aromatic hydrocarbons such as toluene and xylene are preferred, as long as the ethylene-α-olefin copolymer (A) is insoluble in the solvent. The amount of solvent used affects the solubility of the raw materials, but is preferably 0 to 100 times the mass of the ethylene-α-olefin copolymer (A), more preferably 0 to 50 times, and even more preferably 0 to 20 times.

[0058] In the reaction between the ethylene-α-olefin copolymer (A) and the thiol compound, the ratio is not particularly limited, but is usually carried out under conditions of excess thiol compound, and the excess thiol compound can also be used as a solvent. The ratio is preferably 0.1 to 100 molar times, more preferably 0.1 to 50 molar times, and even more preferably 0.1 to 10 molar times relative to the ethylene-α-olefin copolymer (A).

[0059] The reaction temperature is preferably 25 to 300°C, more preferably 25 to 250°C, and even more preferably 25 to 150°C. Depending on the compound and solvent used, the reaction temperature may exceed the boiling point, so an appropriate reaction apparatus such as an autoclave should be selected. The reaction time varies depending on the reaction conditions such as the amount of radical initiator used, the reaction temperature, and the reactivity of the polymers, but is usually in the range of several minutes to 50 hours.

[0060] After the reaction, the radical initiator, excess thiol compound, and reaction solvent can be removed by simple operations such as crystallization, extraction, and washing to obtain the terminal hydroxyethylene-α-olefin copolymer (Z).

[0061] [(Meth)acrylic resin (B)] (Meth)acrylic resin (B) is a (co)polymer of acrylic monomers or methacrylic monomers. The acrylic monomers or methacrylic monomers constituting (meth)acrylic resin (B) may be, for example, monomers derived from fossil fuels or monomers derived from biomass.

[0062] The acrylic monomer or methacrylic monomer constituting the (meth)acrylic resin (B) may be a single type or a combination of two or more types. Here, the (meth)acrylic resin (B) preferably satisfies one of the following requirements (B1) and (B2), and more preferably satisfies both.

[0063] Requirements (B1) The (meth)acrylic resin (B) preferably contains structural units derived from (meth)acrylate having an alkyl group with 1 to 12 carbon atoms, and structural units derived from (meth)acrylate containing a hydroxyl group.

[0064] Specifically, if the (meth)acrylic resin (B) contains structural units derived from (meth)acrylate having an alkyl group with a small number of carbon atoms, for example, structural units derived from (meth)acrylate having an alkyl group with 1 to 12 carbon atoms, the glass transition temperature (Tg) of the (meth)acrylic resin (B) increases, and the adhesiveness of the adhesive composition increases. Here, "structural units derived from (meth)acrylate having an alkyl group with 1 to 12 carbon atoms" refers to structural units corresponding to (meth)acrylate having an alkyl group with 1 to 12 carbon atoms, and specifically, -[-CH2-CR 5 (-C(=O)-OR 4 )-]- General formula (5) (R 4 R is an alkyl group having 1 to 12 carbon atoms. 5(This is either a hydrogen atom or a methyl group.) This is a structural unit represented by [this symbol].

[0065] From the above viewpoint, the (meth)acrylate having an alkyl group having 1 to 12 carbon atoms is more preferably a (meth)acrylate having an alkyl group having 1 to 10 carbon atoms, and even more preferably a (meth)acrylate having an alkyl group having 2 to 8 carbon atoms. The alkyl group may be linear or branched.

[0066] Examples of (meth)acrylates having an alkyl group with 1 to 12 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, and lauryl (meth)acrylate.

[0067] The (meth)acrylic resin (B) has a content of structural units derived from (meth)acrylate having an alkyl group with 1 to 12 carbon atoms, preferably 50 mol% or more, more preferably 55 mol% or more, and even more preferably 60 mol% or more, relative to the total amount of structural units. The content is preferably 99 mol% or less, more preferably 95 mol% or less, and even more preferably 90 mol% or less.

[0068] Furthermore, if the (meth)acrylic resin (B) contains structural units derived from (meth)acrylate containing hydroxyl groups, the number of crosslinking points by the crosslinking agent (C) increases, which increases the crosslinking density of the adhesive composition and makes it easier to achieve a high molecular weight. Such adhesive compositions have excellent mechanical strength in the adhesive layer and are less prone to a decrease in tackiness. Here, "structural units derived from (meth)acrylate containing hydroxyl groups" refers to structural units corresponding to (meth)acrylate containing hydroxyl groups.

[0069] Examples of (meth)acrylates containing the above-mentioned hydroxyl group include hydroxyethyl (meth)acrylate, hydroxyalkyl (meth)acrylates such as hydroxypropyl (meth)acrylate, and hydroxyalkyl (meth)acrylamides such as N-methylol(meth)acrylamide. Of these, from the above viewpoint, hydroxyethyl (meth)acrylate is preferred as the (meth)acrylate containing the above-mentioned hydroxyl group.

[0070] In other words, examples of "structural units derived from (meth)acrylates containing a hydroxyl group" include structural units derived from hydroxyalkyl (meth)acrylates and structural units derived from hydroxyalkyl(meth)acrylamides, specifically, -[-CH2-CR 7 (-C(=O)-OR 6 -OH)-]- General formula (6) (R 6 R is an alkanediyl group, preferably an ethane-1,2-diyl group or a propane-1,3-diyl group, and more preferably an ethane-1,2-diyl group. 7 (This is either a hydrogen atom or a methyl group.) A structural unit represented by, -[-CH2CR 9 (-C(=O)-NH-R 8 -OH)-]- General formula (7) (R 8 This is an alkanediyl group (for example, a methanediyl group). 9(This is either a hydrogen atom or a methyl group.) Examples of structural units are given by the above general formula (6). In one exemplary and preferred embodiment of the present invention, the "structural unit derived from a (meth)acrylate containing a hydroxyl group" is the structural unit represented by the above general formula (6).

[0071] The (meth)acrylic resin (B) preferably contains 0.1 mol% or more, more preferably 0.2 mol% or more, and even more preferably 0.3 mol% or more of structural units derived from the above-mentioned hydroxyl group-containing (meth)acrylate, relative to the total amount of structural units. Furthermore, the above content is preferably 10 mol% or less, more preferably 5 mol% or less, and even more preferably 3 mol% or less.

[0072] Furthermore, the (meth)acrylic resin (B) may be a copolymer having structural units derived from monomers (or oligomers) having crosslinking functional groups, which are different from the (meth)acrylates having alkyl groups with 1 to 12 carbon atoms or (meth)acrylates containing hydroxyl groups. Examples of monomers having crosslinking functional groups include (meth)acrylic acid and (meth)acrylamide.

[0073] Furthermore, the (meth)acrylic resin (B) may be a copolymer having structural units derived from vinyl monomers other than those mentioned above, if necessary. Examples of such vinyl monomers include styrene and vinyl acetate.

[0074] The content of each structural unit in (meth)acrylic resin (B) can be determined using an appropriate method, for example, by pyrolysis gas chromatography-mass spectrometry (pyrolysis GC-MS), as shown in the example below.

[0075] Requirements (B2) It is preferable that the peak temperature of the loss tangent (tanδ) due to the glass transition temperature, as measured by the temperature dependence of dynamic viscoelasticity (frequency 1 Hz, -100 to 200°C), is less than 0°C.

[0076] Specifically, if the peak temperature of the loss tangent (tanδ) due to the glass transition temperature, measured by the temperature dependence of the dynamic viscoelasticity of (meth)acrylic resin (B) (frequency 1 Hz, -100 to 200°C), is within a specific range, for example, below 0°C, then the adhesive composition, which is a thin film adhesive layer, can exhibit adhesiveness over a wide temperature range.

[0077] From the above viewpoint, the (meth)acrylic resin (B) has a peak temperature of loss tangent (tanδ) that is more preferably -80°C or higher, and even more preferably -70°C or higher. Furthermore, the peak temperature is more preferably less than 0°C, and even more preferably -5°C or lower. The peak temperature of the loss tangent (tanδ) of (meth)acrylic resin (B) can be adjusted to the above range by changing the monomers used for polymerization and their ratios.

[0078] Method for manufacturing (meth)acrylic resin (B) (Meth)acrylic resin (B) can be synthesized by known polymerization methods using monomers (or oligomers) that serve as materials for each of the above structural units. The polymerization method is not particularly limited as long as it is a radical polymerization method, including bulk polymerization, solution polymerization, and suspension polymerization. Of these, solution polymerization is preferred because it allows for easy control of the glass transition temperature (Tg) and other properties of (meth)acrylic resin (B), and facilitates the synthesis of (meth)acrylic resin (B) with desired properties.

[0079] Polymerization initiators may be used during polymerization. Examples of the above polymerization initiators include dicumyl peroxide, benzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, 1,1-bis(tert-butyl peroxy)cyclohexane, α,α'-azobisisobutyronitrile, acetyl peroxide, tert-butyl peroxypivalate, tert-butyl hydroperoxide, cumene hydroperoxide, tert-hexyl peroxypivalate, 2,2'-azobis-(2,4-dimethylvaleronitrile), lauryl peroxide, tert-butyl peroxyneohexanoate, di-tert-butyl peroxide, azodicyclohexylcarbonitride, α,α-dimethyl azodiisobutyrate, succinic acid peroxide, dicumene peroxide, and benzoyl dichloroperoxide. Examples of solvents used in the above solution polymerization include ethyl acetate, butyl acetate, benzene, toluene, xylene, cyclohexane, and methyl ethyl ketone.

[0080] [Crosslinking agent (C)] The crosslinking agent (C) crosslinks the (meth)acrylic resin (B) to further enhance the adhesiveness of the adhesive composition according to this embodiment.

[0081] Examples of crosslinking agents (C) include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, and resolcin diglycidyl ether; isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylolpropane toluene diisocyanate 3 adduct, and polyisocyanates; and trimethylol This includes aziridine compounds such as lupropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide), N,N'-toluene-2,4-bis(1-aziridinecarboxamide), and trimethylolpropane-tri-β-(2-methylaziridine)propionate, as well as melamine compounds such as hexamethoxymethylolmelamine. The crosslinking agent (C) may be used alone or in combination of multiple types.

[0082] Preferably, the crosslinking agent (C) is blended in such a way that the number of functional groups that can bond with the (meth)acrylic resin (B) in the crosslinking agent (C) (including the number of functional groups generated by the dissociation of the blocking agent when the crosslinking agent (C) contains a blocked isocyanate) does not exceed the number of functional groups present in the (meth)acrylic resin (B). However, a larger amount may be blended when new functional groups are generated by the crosslinking reaction or when the crosslinking reaction proceeds slowly.

[0083] [Content of each component] The adhesive composition according to this embodiment, when the sum of the content of the terminal hydroxyethylene-α-olefin copolymer (Z), the (meth)acrylic resin (B), and the crosslinking agent (C) is 100% by mass, The amount of the terminal hydroxyethylene-α-olefin copolymer (Z) is 0.5% by mass or more and 50% by mass or less. Preferably, the amount of the (meth)acrylic resin (B) is 47% by mass or more and 99% by mass or less, and the amount of the crosslinking agent (C) is 0.5% by mass or more and 5% by mass or less.

[0084] When the content of the above-mentioned terminal hydroxyethylene-α-olefin copolymer (Z) is 0.5% by mass or more, the low-temperature flexibility of the adhesive composition can be further enhanced. From this point of view, the content of the above-mentioned terminal hydroxyethylene-α-olefin copolymer (Z) is more preferably 1% by mass or more, and even more preferably 3% by mass or more. However, in order to reliably obtain both sufficiently high low-temperature flexibility and sufficiently high adhesiveness, it may be preferable to set the content of the above-mentioned terminal hydroxyethylene-α-olefin copolymer (Z) to, for example, 15% by mass or more, or 20% by mass or more.

[0085] When the content of the above-mentioned terminal hydroxyethylene-α-olefin copolymer (Z) is 50% by mass or less, the tackiness and bleed resistance of the adhesive composition can be further improved. From this point of view, the content of the above-mentioned terminal hydroxyethylene-α-olefin copolymer (Z) is more preferably 40% by mass or less, and even more preferably 35% by mass or less.

[0086] From the above viewpoint, the content of the terminal hydroxyethylene-α-olefin copolymer (Z) is more preferably 1% by mass or more and 40% by mass or less, and even more preferably 3% by mass or more and 35% by mass or less.

[0087] When the content of the above-mentioned (meth)acrylic resin (B) is above a certain amount, for example, 47% by mass or more, a larger amount of (meth)acrylic resin (B) is contained in the adhesive composition, resulting in a higher crosslinking density and higher molecular weight of the adhesive composition, thus providing excellent mechanical strength and less likelihood of a decrease in adhesiveness. From this point of view, the content of the above-mentioned (meth)acrylic resin (B) is more preferably 55% by mass or more, and even more preferably 60% by mass or more.

[0088] If the content of the (meth)acrylic resin (B) is below a certain amount, for example, 99% by mass or less, a larger amount of terminal hydroxyethylene-α-olefin copolymer (Z) and crosslinking agent (C) will be contained in the adhesive composition, thereby further enhancing the low-temperature flexibility and adhesiveness of the adhesive composition. From this point of view, the content of the (meth)acrylic resin (B) is more preferably 97% by mass or less, and even more preferably 95% by mass or less. However, in order to reliably obtain both sufficiently high low-temperature flexibility and sufficiently high adhesiveness, it may be preferable to set the content of the (meth)acrylic resin (B) to, for example, 85% by mass or less or 80% by mass or less.

[0089] From the above viewpoint, the content of the (meth)acrylic resin (B) is more preferably 55% by mass or more and 97% by mass or less, and even more preferably 60% by mass or more and 95% by mass or less.

[0090] When the content of the above-mentioned crosslinking agent (C) is 0.5% by mass or more, the adhesive composition tends to aggregate, and so-called adhesive residue, where the adhesive composition remains on the surface of the adherend after pressing, is less likely to occur. From this point of view, the content of the above-mentioned crosslinking agent (C) is more preferably 0.7% by mass or more, and even more preferably 1% by mass or more.

[0091] When the content of the crosslinking agent (C) is 5% by mass or less, a larger amount of (meth)acrylic resin (B) is contained in the adhesive composition, resulting in a higher crosslinking density and higher molecular weight of the adhesive composition, thus providing excellent mechanical strength and less likelihood of a decrease in adhesiveness. From this point of view, the content of the crosslinking agent (C) is more preferably 3% by mass or less, and even more preferably 2.5% by mass or less.

[0092] From the above viewpoint, the content of the crosslinking agent (C) is more preferably 0.7% by mass or more and 3% by mass or less, and even more preferably 1% by mass or more and 2.5% by mass or less.

[0093] [Additives] In addition to the above-mentioned terminal hydroxyethylene-α-olefin copolymer (Z), the above-mentioned (meth)acrylic resin (B), and the above-mentioned crosslinking agent (C), the adhesive composition of the present invention may also contain, to the extent that it does not impair the effects of the present invention, at least one selected from organic solvents, antistatic agents, silane coupling agents, ultraviolet absorbers, antioxidants, tackifying resins, plasticizers, defoaming agents, fillers, stabilizers, softeners, and wettability modifiers as an additive.

[0094] [Method for manufacturing adhesive compositions] The adhesive composition according to this embodiment can be prepared by mixing the above-mentioned terminal hydroxyethylene-α-olefin copolymer (Z), (meth)acrylic resin (B), and crosslinking agent (C) with a solvent of any choice in proportion to the above-mentioned content. That is, the production method according to the present invention includes the step of mixing the above-mentioned terminal hydroxyethylene-α-olefin copolymer (Z), the above-mentioned (meth)acrylic resin (B), and the above-mentioned crosslinking agent (C). Here, in the mixing, the mixture containing the above-mentioned (meth)acrylic resin (B), the above-mentioned terminal hydroxyethylene-α-olefin copolymer (Z), and the above-mentioned crosslinking agent (C) may also contain a solvent. Furthermore, the above-mentioned additives may also be contained in the mixture.

[0095] Examples of the solvents mentioned above include ethyl acetate, butyl acetate, benzene, toluene, xylene, cyclohexane, and methyl ethyl ketone. Herein, in a preferred and exemplary embodiment of the present invention, the terminal hydroxyethylene-α-olefin copolymer (Z) is produced by the method described above in the "Method for Producing a Terminal Hydroxyethylene-α-Olefin Copolymer (Z)". Therefore, the above production method may further include a step of obtaining the terminal hydroxyethylene-α-olefin copolymer (Z) by the method described above in the "Method for Producing a Terminal Hydroxyethylene-α-Olefin Copolymer (Z)".

[0096] [Adhesive sheet (adhesive layer)] The adhesive composition described above can be suitably used as an adhesive, and one suitable application is an adhesive sheet.

[0097] The adhesive sheet of the present invention has an adhesive layer formed from the above-described adhesive composition. The adhesive layer can be manufactured, for example, by forming it into a film and removing the solvent. More specifically, the adhesive sheet according to this embodiment can be obtained, for example, by coating the adhesive composition according to this embodiment onto a separator or substrate to form a film, and then heating it. More specifically, the adhesive composition according to this embodiment can be applied to a separator or substrate by known methods such as the roll coater method, reverse roll coater method, gravure roll method, bar coat method, comma coater method, and die coater method, and the applied adhesive composition can be dried to produce the adhesive sheet according to this embodiment.

[0098] Examples of adhesive sheets include a double-sided adhesive sheet having only the adhesive layer described above, a double-sided adhesive sheet having a substrate and the adhesive layer described above formed on both sides of the substrate, a single-sided adhesive sheet having a substrate and the adhesive layer described above formed on one side of the substrate, and adhesive sheets in which a peelable separator is attached to the side of the adhesive layer of these adhesive sheets that is not in contact with other layers.

[0099] The conditions for forming the adhesive layer are as follows, for example: The composition is applied to a separator or substrate and dried at a temperature of 60 to 120°C, preferably 70 to 110°C, for 1 to 15 minutes, preferably 2 to 10 minutes, to form a coating film. Subsequently, if applied to a separator, the substrate or separator is bonded to the coating film on the side without the separator; if applied to a substrate, the separator is bonded to the coating film. Subsequently, the coating is cured (aged) for at least 1 day, preferably 3 to 10 days, at a temperature of 5 to 60°C, preferably 15 to 50°C, and at an environment of 30 to 70% RH, preferably 40 to 70% RH. Crosslinking under the above aging conditions allows for efficient formation of a crosslinked body (network polymer). In the case of a coating film sandwiched between separators, after aging, one separator is peeled off and the substrate is bonded to the exposed adhesive layer.

[0100] Examples of substrates and separators include plastic films such as polyester (e.g., polyethylene terephthalate, polyethylene naphthalate), polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, acrylonitrile-butadiene-styrene copolymer, ethylene-vinyl acetate copolymer, polyamide, polyurethane, and polyvinyl chloride; woven fabrics, nonwoven fabrics; paper, glass, etc. The substrate and separator may each have a surface that has been treated to release flammability. The thickness of the adhesive layer is typically 3 to 1000 μm, preferably 5 to 500 μm. The thickness of the substrate and separator is typically 10 to 1000 μm. From the viewpoint of improving cohesive strength, adhesive strength, and re-peelability, the gel fraction of the adhesive layer is preferably 40 to 90% by mass, more preferably 50 to 70% by mass.

[0101] [Application] The adhesive composition according to this embodiment can be used as an adhesive processed product or sealing material such as sheets, tapes, labels, and double-sided tapes for various applications where adhesiveness is required.

[0102] The adhesive composition and adhesive sheet of the present invention exhibit good adhesion to substrates such as polyolefins like polypropylene and polyethylene, resins other than polyolefins, and glass, and can be used in a variety of components such as display components, touch panel components, automotive components, aircraft components, ship components, electrical appliance components, building material components, electronic devices, and conductive substrates.

[0103] Touch panels are used in devices such as smartphones, tablet computers, and in-vehicle devices like car navigation systems. Examples of electronic devices include organic EL devices, solar cells, and sensor devices.

[0104] Examples The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. In the following examples and comparative examples, each physical property was measured or evaluated by the following methods.

[0105] [Loss tangent (tanδ) peak temperature] The loss tangent (tanδ) was measured using a rheometer (ARES-G2, manufactured by T.A. Instruments). Specifically, a sample formed into a disc shape with a diameter of 8 mm and a thickness of 0.4 mm was used. The sample was sandwiched between two parallel plates (8 mmφ) attached to the rheometer (with a gap of 0.4 mm between the parallel plates). The temperature dependence of the dynamic viscoelasticity (specifically, the loss modulus G'' and the storage modulus G') from -100 to 200°C was measured at a frequency of 1 Hz and a heating rate of 3°C / min. The peak temperature of the loss tangent (tanδ) due to the glass transition temperature was then measured. Here, the loss tangent (tanδ) is the ratio of the loss modulus G'' to the storage modulus G'.

[0106] [Number-average molecular weight (Mn) and molecular weight distribution (Mw / Mn)] The following was determined using a high-speed GPC measurement device. Measurement device: Tosoh Corporation HLC8320GPC Mobile phase: THF (manufactured by Wako Pure Chemical Industries, Ltd., stabilizer-free, liquid chromatography grade) Column: Two TSKgel Super Multipore HZ-M columns manufactured by Tosoh Corporation were connected in series. Sample concentration: 5 mg / mL Mobile phase flow rate: 0.35mL / min Measurement temperature: 40℃ Standard sample for calibration curve: PStQuick MP-M manufactured by Tosoh Corporation

[0107] < 1 H-NMR> [Measurement conditions] Measurement device: JEOL ECX400P nuclear magnetic resonance spectrometer Nucleus for measurement: 1 H (400MHz) Measurement mode: Single pulse Pulse width: 45° (5.25 μsec) Points: 32k Measurement range: 20 ppm (-4 to 16 ppm) Repeat time: 7.0 seconds Total number of times: 64 Measurement solvent: Deuterated chloroform Sample concentration: approx. 20 mg / 0.6 mL Measurement temperature: 25℃ Window function: exponential (BF: 0.12Hz) Chemical shift standard: Chloroform (7.26 ppm). After adding a drop of heavy water to the sample and vigorously stirring, the hydroxyl groups were deuterated, and then the measurement was performed.

[0108] [Concentration of terminal hydroxyethylene-propylene copolymers (Za) containing two or more hydroxyl groups] For the measurement sample, terminal hydroxyethylene-propylene copolymer (Za), the peaks for hydrogen atoms 1-8 in the following equations are 1 The results were measured by 1H-NMR.

[0109] [ka]

[0110] In each formula, dashed lines indicate bonds other than those of hydrogen atoms and represent the main chain of the ethylene-propylene copolymer. Peaks for each hydrogen atom (1-11) are observed near the locations shown below. Furthermore, since disubstituted olefin terminals and trisubstituted olefin terminals in the unsaturated bonds of the ethylene-propylene copolymer (A-1) used as a raw material were hardly observed, these structures and the epoxy group-containing terminals generated from these structures were not considered in the calculations. • Peaks of hydrogen atoms 1 and 2: 3.5 ppm to 3.9 ppm • Hydrogen atom 3 peak: 3.0 ppm • Hydrogen atom 4 peak: 2.8 ppm • Hydrogen atom 5 peak: 2.2~2.9 ppm • Hydrogen atom 6 peak: 2.4~2.9 ppm • Hydrogen atom 7 peak: 5.9 ppm • Hydrogen atom 8 peak: 4.6 ppm The percentage of terminals with two or more hydroxyl groups is as follows:

[0111] [[If formula (1-a) is present]] -CH2-N-(CH2CH2OH)2 formula (1-a) The percentage of terminal cells containing two or more hydroxyl groups (%) = 100 × [(integrated intensity of signal 1 + integrated intensity of signal 2) / 5] / [(integrated intensity of signal 1 + integrated intensity of signal 2) / 5 + integrated intensity of signal 3 + {integrated intensity of signal 4 + integrated intensity of signal 5 - [6 × (integrated intensity of signal 1 + integrated intensity of signal 2) / 5]} / 2 + integrated intensity of signal 7 + integrated intensity of signal 8 / 2]

[0112] [[If formula (2-a) is present]] -CH2-S-CH2-CH(-OH)-CH2OH Formula (2-a) The percentage of terminal cells containing two or more hydroxyl groups (%) = 100 × [(integrated intensity of signal 1 + integrated intensity of signal 2) / 3] / [(integrated intensity of signal 1 + integrated intensity of signal 2) / 3] + integrated intensity of signal 7 + integrated intensity of signal 8 / 2]

[0113] [Calculation of the content of vinyl group and vinylidene group in the unsaturated end of ethylene-propylene copolymer (A-1)] For the ethylene-propylene copolymer (A-1) used as the measurement sample, the peaks for each hydrogen atom I to IV in the following equations are... 1 The results were measured by 1H-NMR.

[0114] [ka]

[0115] In each formula, dashed lines indicate bonding with atoms other than hydrogen atoms. The peaks for each hydrogen atom I-IV are observed in the vicinity of the following locations. • Peak of carbon atom I: 5.9 ppm • Peak of carbon atom I': 4.9 ppm • Peak of carbon atom II: 4.6 ppm • Peak of carbon atom III: 5.3 ppm • Peak of carbon atom IV: 4.9 ppm Furthermore, since it is not possible to distinguish between the peaks of IV and I', the integrated intensity of IV is calculated using the peak of I. The quantitative formula for the content of vinyl groups at the end of unsaturated ends is as follows: The percentage of vinyl groups at the unsaturated end (%) = 100 × integrated intensity of signal I / [integrated intensity of signal I + (integrated intensity of signal II / 2) + (integrated intensity of signal III / 2) + (integrated intensity of signal I' + integrated intensity of signal IV - integrated intensity of signal I × 2)] The percentage of vinylidene groups at the unsaturated end (%) = 100 × (integrated intensity of signal II / 2) / [integrated intensity of signal I + (integrated intensity of signal II / 2) + (integrated intensity of signal III / 2) + (integrated intensity of signal I' + integrated intensity of signal IV - integrated intensity of signal I × 2)]

[0116] [Calculation of ethylene and propylene content in terminal hydroxyethylene-propylene copolymer (Za) or ethylene-propylene copolymer (A-1)] the above 1 The spectra obtained by 1H-NMR measurements show ethylene and propylene units in the main chain. The ethylene and propylene content was calculated from the integrated intensity of each signal.

[0117] [ka]

[0118] In each formula, dashed lines indicate bonding with atoms other than hydrogen atoms. The peaks for each hydrogen atom, A through C, are observed in the following ranges. • Hydrogen atom peak: 0.95 ppm ~ 1.4 ppm • Hydrogen atom peak: 0.95 ppm ~ 1.4 ppm • Hydrogen atom peak: 1.4 ppm ~ 1.7 ppm Furthermore, since it is not possible to distinguish between peaks A and B, the integrated intensity of A is calculated using peak C. The quantitative formulas for ethylene and propylene content are as follows: Ethylene content (mol%) = 100 × [(Integrated intensity of signal: A + Integrated intensity of signal: B - 2 × Integrated intensity of signal: C) / 4] / {[(Integrated intensity of signal: A + Integrated intensity of signal: B - 2 × Integrated intensity of signal: C) / 4] + Integrated intensity of signal: C} Propylene content (mol%) = 100 × Integrated intensity of signal:U / {[(Integrated intensity of signal:A + Integrated intensity of signal:B - 2 × Integrated intensity of signal:U) / 4] + Integrated intensity of signal:U}

[0119] [Ethylene-propylene copolymer (A-1)] [Synthesis Example A1] Synthesis of ethylene-propylene copolymer (A-1) 500 mL of xylene was added to a 1.0 L glass reactor that had been thoroughly purged with nitrogen. The reactor was then maintained at 110°C, and while stirring the inside of the polymerizer at 600 rpm, ethylene, propylene, and nitrogen were continuously supplied at 78 L / h, 44 L / h, and 52 L / h, respectively, until the liquid and gas phases were saturated. While ethylene and propylene were continuously supplied, 0.10 mL (0.10 mmol) of a toluene solution of triisobutylaluminum (1.0 mol / L), 2.5 mL (0.005 mmol) of a toluene solution of dimethylsilylbis(2-methyl-4-phenylindenyl)hafnium dichloride (0.002 mol / L), and then 2.0 mL (0.020 mmol) of a toluene solution of triphenylcarbenium tetrakis(pentafluorophenyl) borate (hereinafter also referred to as Ph3CB(C6F5)4) (0.01 mol / L) were added, and polymerization was carried out at 110°C for 16 minutes under atmospheric pressure. Polymerization was stopped by adding a small amount of isobutanol. The resulting polymerization reaction solution was washed with dilute hydrochloric acid, and the solvent of the organic layer obtained by liquid-liquid extraction was removed under reduced pressure to obtain an ethylene-propylene copolymer. By drying the copolymer under reduced pressure at 130°C for 10 hours, 8.45 g of ethylene-propylene copolymer (A-1) was obtained.

[0120] The obtained ethylene-propylene copolymer (A-1) had Mw=3800, Mn=2200, Mw / Mn=1.73, ethylene content=50mol%, and propylene content=50mol%. 1 The vinyl group content and vinylidene group content in the unsaturated end, as measured by 1H-NMR, were 81% and 16%, respectively.

[0121] [Terminal hydroxyethylene propylene copolymer (Za)] [Production Example Z1] Synthesis of terminal hydroxyethylene-propylene copolymer (Za) In a 300 mL round-bottom flask containing a stirring bar, 25.2 g of ethylene-propylene copolymer (A-1) obtained in Synthesis Example A1 was dissolved in 150 mL of dichloromethane. Then, at room temperature, while stirring with a magnetic stirrer, 4.2 g of metachloroperbenzoic acid (water content approximately 30 wt%) was added and the mixture was reacted for 72 hours. After that, a small amount of saturated sodium bicarbonate solution and 25 wt% sodium sulfite aqueous solution were added to stop the reaction. The resulting reaction solution was washed with saturated sodium bicarbonate solution, and the organic layer obtained by liquid-liquid extraction was dried with sodium sulfate. The solvent was then removed by vacuum distillation to obtain 24.3 g of terminal epoxy ethylene-propylene copolymer. Next, 20.0 g of terminal epoxyethylene-propylene copolymer was added to a 150 mL Schlenk tube containing a stirring bar. Subsequently, 5.9 g of diethanolamine was added, and the mixture was dried at room temperature for 5 hours. Then, 20 mL of xylene was added, and the mixture was heated in an oil bath to 135°C and reacted for 8 hours. The reaction solution was cooled to room temperature, and 100 mL of toluene was added. The resulting organic layer was washed with water, dried over sodium sulfate, and the solvent was removed by vacuum distillation to obtain 20.2 g of terminal hydroxyethylene-propylene copolymer (Za).

[0122] The obtained terminal hydroxyethylene-propylene copolymer (Za) showed no melting point, with Mw=4580, Mn=1980, Mw / Mn=2.31, ethylene content=50 mol%, and propylene content=50 mol%. 1 Excluding saturated ends determined by 1H-NMR, 67% of the ends contain two or more hydroxyl groups.

[0123] [Graft-modified ethylene-propylene copolymer (X-1)] [Manufacturing Example X1] Synthesis of graft-modified ethylene-propylene copolymer (X-1) A 2 L stainless steel autoclave, thoroughly purged with nitrogen, was charged with 760 mL of heptane and 120 g of propylene. After raising the temperature of the system to 150 °C, the total pressure was increased to 3 MPa-G by supplying hydrogen at 0.85 MPa and ethylene at 0.19 MPa. Next, 0.4 mmol of triisobutylaluminum, [methylphenylmethylene (η) 5 -cyclopentadienyl)(η 5 Polymerization was initiated by introducing 0.0002 mmol of -2,7-di-tert-butylfluorenyl)zirconium dichloride and 0.002 mmol of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate under pressure with nitrogen and stirring at 400 rpm. Subsequently, the total pressure was maintained at 3 MPa-G by continuously supplying only ethylene, and polymerization was carried out at 150°C for 5 minutes. Polymerization was stopped by adding a small amount of ethanol to the system, and unreacted ethylene, propylene, and hydrogen were purged. The resulting polymerization solution was washed three times with 1000 mL of 0.2 mol / L hydrochloric acid, followed by three washes with 1000 mL of distilled water, dried with magnesium sulfate, and the solvent was removed under reduced pressure to obtain crude ethylene-propylene copolymer. In a 1 L stainless steel autoclave, 100 mL of a hexane solution of 0.5% by mass Pd / alumina catalyst and 500 mL of a hexane solution of the obtained crude ethylene-propylene copolymer were added. After sealing the autoclave, nitrogen purging was performed. The temperature was then raised to 140°C while stirring, the system was purged with hydrogen, and the pressure was increased to 1.5 MPa with hydrogen for a hydrogenation reaction to be carried out for 15 minutes. After filtering the reaction solution to separate the hydrogenation catalyst, the solvent was removed from the resulting filtrate under reduced pressure, and the ethylene-propylene copolymer was obtained by drying under reduced pressure at 80°C for 24 hours. In a 500 mL glass reactor equipped with a stirrer, nitrogen inlet tube, water-cooled condenser, and thermometer, 120 g of ethylene-propylene copolymer, 15 g of 2-methyl-3-buten-2-ol, and 3 g of di-tert-butyl peroxide were placed, and the reactor was purged with nitrogen for 1 hour to expel dissolved oxygen. The reactor temperature was then raised to 160°C and the reaction was carried out for 3 hours. After that, the reactor temperature was raised to 180°C, and the decomposition products of unreacted 2-methyl-3-buten-2-ol and di-tert-butyl peroxide were removed under reduced pressure (10 Torr) to obtain graft-modified ethylene-propylene copolymer (X-1). The obtained graft-modified ethylene-propylene copolymer (X-1) showed no melting point, with Mw=5300, Mn=2950, ​​Mw / Mn=1.80, ethylene content=50 mol%, and propylene content=50 mol. 1 Excluding saturated ends determined by 1H-NMR, the percentage of ends containing two or more hydroxyl groups is 0%.

[0124] [(Meth)acrylic resin (B-1)] [Manufacturing Example B1] Synthesis of (meth)acrylic resin (B-1) In a temperature-controllable reactor equipped with a stirrer, 350 parts by mass of ethyl acetate as the polymerization solvent and 40 parts by mass of toluene were charged, the reactor was purged with nitrogen, and the temperature was raised to 75°C. Subsequently, to the resulting mixture of ethyl acetate and toluene, a mixture of 316 parts by mass of n-butyl acrylate, 43 parts by mass of ethyl acrylate, 50 parts by mass of vinyl acetate, 9 parts by mass of acrylic acid, 2 parts by mass of hydroxyethyl acrylate, and 2 parts by mass of benzoyl peroxide as a polymerization initiator was successively added, and the mixture was then reacted for 5 hours. Five hours after the completion of the additions, the resulting reaction mixture was diluted with 120 parts by mass of toluene to obtain an ethyl acetate / toluene solution containing (meth)acrylic resin with a solid content of 45%.

[0125] Here, the (meth)acrylic resin obtained in this manufacturing example is referred to as (meth)acrylic resin (B-1). The peak temperature of the loss tangent (tanδ) due to the glass transition temperature, measured by the temperature dependence of dynamic viscoelasticity (frequency 1 Hz, -100 to 200°C) of (meth)acrylic resin (B-1) obtained by volatilizing the solvent from the resulting ethyl acetate / toluene solution, was -47°C.

[0126] The composition of (meth)acrylic resin (B-1) was quantified by pyrolysis gas chromatography-mass spectrometry (pyrolysis GC-MS). The content of structural units derived from (meth)acrylate having an alkyl group with 1 to 12 carbon atoms was 80 mol%, and the content of structural units derived from (meth)acrylate containing a hydroxyl group was 0.5 mol%. The quantification by pyrolysis GC-MS was performed under the following conditions.

[0127] Pyrolysis apparatus: JAIJHP-5 manufactured by Nippon Analytical Engineering Co., Ltd. Thermal decomposition temperature: 590℃ GC device: Agilent 6890N Column: Agilent DB-5MS Column temperature: 40℃ Column flow rate: 0.9 mL / min (Mobile phase: Helium) MS device: JMS-Q1000GC manufactured by JEOL

[0128] [Crosslinking agent (C-1)] As the crosslinking agent (C-1), we used Takenate D-101E (an isocyanate compound, "Takenate" is a registered trademark of Mitsui Chemicals, Inc.).

[0129] [Example 1, Comparative Examples 1-2] In each of Example 1 and Comparative Examples 1-2, either a terminal hydroxyethylene-propylene copolymer (Za) or a graft-modified ethylene-propylene copolymer (X-1), an ethyl acetate / toluene solution containing the above-mentioned (meth)acrylic resin (B-1), and a crosslinking agent (C-1) were stirred and mixed at room temperature to obtain an ethyl acetate / toluene solution of an adhesive composition. Here, the ratio of the mass of either the terminal hydroxyethylene-propylene copolymer (Za) or the graft-modified ethylene-propylene copolymer (X-1) contained in the ethyl acetate / toluene solution in the adhesive composition to the mass of the (meth)acrylic resin (B-1) and the crosslinking agent (C-1) is as shown in Table 1. In the evaluation of each physical property described below, an ethyl acetate / toluene solution obtained by adding toluene to the mixture obtained by the aforementioned stirring and mixing, and adjusting the mass ratio of ethyl acetate to toluene to 40 / 60 (hereinafter referred to as "ethyl acetate / toluene (40 / 60 mass%) solution of the adhesive composition") was used.

[0130] [Adhesion evaluation] Adhesion was evaluated for each of the ethyl acetate / toluene (40 / 60 mass%) solutions of the adhesive compositions obtained in the examples and comparative examples, as follows. An ethyl acetate / toluene (40 / 60% by mass) solution of the obtained adhesive composition was applied to release paper so that the film thickness after drying was 25 μm. After drying at 100°C for 10 minutes, a 50 μm PET film was pressed onto the applied surface to prepare an adhesive sheet having a base layer made of PET film and an adhesive layer made of the adhesive composition. The sheet was left at 50°C for 3 days to allow the adhesive composition to crosslink sufficiently.

[0131] The above adhesive sheet was cut to a width of 25 mm and a length of 150 mm to prepare test specimens. The release paper was peeled off the test specimens to expose the adhesive layer, and the exposed adhesive layer was brought into contact with a PP board in an atmosphere of 23°C. The test specimens were then pressed down by passing a 2 kg rubber roll back and forth twice. After standing for 20 minutes, the 180° peel strength was measured at a speed of 300 mm / min in accordance with JIS Z0237.

[0132] The adhesive properties were evaluated based on the obtained peel strength. The evaluation results are shown in Table 1. The meaning of the symbols in the table is as follows. ○: Peel strength of 3N / 25mm or more △: Peel strength less than 3N / 25mm, 1N / 25mm or more. ×: Peel strength less than 1N / 25mm Here, the symbol "○" indicates that the adhesive sheet and the PP board are bonded together with sufficient strength. The symbol "△" indicates that the adhesive sheet and the PP board are bonded together with a certain degree of strength. The symbol "×" indicates a state of poor adhesion (non-adhered state) between the adhesive sheet and the PP board.

[0133] When the adhesive composition of the present invention is used as an adhesive for adhesive sheets or the like, a higher adhesive strength is preferable because it prevents the substrates from peeling apart.

[0134] [Low-temperature flexibility evaluation] Low-temperature flexibility was evaluated for each of the ethyl acetate / toluene (40 / 60 mass%) solutions of the adhesive compositions obtained in the examples and comparative examples, as follows. A 40 / 60% by mass ethyl acetate / toluene (40 / 60 mass) solution of the obtained adhesive composition was applied to release paper so that the film thickness after drying would be 25 μm. The mixture was dried at 100°C for 10 minutes, and the release paper was peeled off the resulting laminate to obtain a sheet made of the adhesive composition.

[0135] The dynamic viscoelasticity of the obtained adhesive composition sheet was measured at -20°C at a frequency of 1 Hz using a rheometer (ARES-G2, T.A. Instruments) with a parallel plate (8 mmφ) measuring fixture. Specifically, a sample made by molding the adhesive composition sheet into a disc shape with a diameter of 8 mm and a thickness of 0.4 mm was used. The sample was sandwiched between two parallel plates (8 mmφ) attached to the rheometer (with a gap of 0.4 mm between the parallel plates), and the loss modulus G'' and storage modulus G' were measured at -20°C at a frequency of 1 Hz. Low-temperature flexibility was evaluated from the obtained storage modulus G'. The evaluation results are shown in Table 1. The meaning of the symbols in the table is as follows. ○: Storage modulus G' is 0.1 MPa or higher and less than 0.5 MPa. △: Storage modulus G' is 0.5 MPa or higher and less than 1.0 MPa. ×: Storage modulus G' is 1.0 MPa or higher

[0136] Here, the symbol "○" indicates that the adhesive is sufficiently soft, and when the adhesive sheet obtained by combining it with the substrate is bent, the adhesive can adequately follow the movement of the substrate, making it extremely unlikely that the adhesive will peel off from the substrate (i.e., it is extremely unlikely that the adhesive will peel off due to insufficient followability when the substrate is bent).

[0137] The symbol "△" indicates that the adhesive is somewhat soft, and when the adhesive sheet obtained by combining it with the substrate is bent, the adhesive can follow the movement of the substrate to some extent, making it somewhat difficult for the adhesive to peel off from the substrate (i.e., it is somewhat difficult for the adhesive to peel off due to insufficient followability when the substrate is bent).

[0138] The symbol "×" indicates that the adhesive is hard, and when the adhesive sheet obtained by combining it with the substrate is bent, the adhesive cannot follow the movement of the substrate, making it prone to peeling of the adhesive from the substrate (i.e., it is prone to peeling of the adhesive due to insufficient conformity when the substrate is bent).

[0139] When the adhesive composition of the present invention is used as an adhesive for adhesive sheets, the lower the storage modulus G' at -20°C, the better the low-temperature flexibility. Therefore, when the adhesive composition of the present invention is combined with a substrate to form an adhesive sheet, the adhesive can follow the bending of the substrate, and peeling of the adhesive can be suppressed, which is preferable.

[0140] [Bleed resistance evaluation] The bleed resistance was evaluated for each of the ethyl acetate / toluene (40 / 60 mass%) solutions of the adhesive compositions obtained in the examples and comparative examples, as follows. An ethyl acetate / toluene (40 / 60% by mass) solution of the obtained adhesive composition was applied to release paper so that the film thickness after drying would be 50 μm. After drying at 100°C for 10 minutes, a 50 μm PET film was pressed onto the applied surface to create an adhesive sheet having a base layer made of PET film and an adhesive layer made of the adhesive composition. The sheet was left at 50°C for 3 days to allow the adhesive composition to crosslink sufficiently. The above adhesive sheet was cut to a width of 25 mm and a length of 150 mm to prepare test specimens. The release paper was peeled off the test specimens to expose the adhesive layer, and the exposed adhesive layer was brought into contact with a glass plate in an atmosphere of 23°C. The test specimens were then pressed down by passing a 2 kg rubber roll back and forth twice. After standing for 20 minutes, a 180° peel was performed at a speed of 300 mm / min, and the surface of the glass plate after peeling was observed visually. The bleed resistance was evaluated by visually observing the surface of the glass plate. The evaluation results are shown in Table 1. The meaning of the symbols in the table is as follows. ○: No liquid deposits were found. ×: Liquid deposits were observed. Here, the symbol "○" indicates that the adhesive is in a state of excellent bleed resistance. The symbol "×" indicates that the adhesive is in a state of poor bleed resistance. When the adhesive composition of the present invention is used as an adhesive for adhesive sheets or the like, it is preferable that it has excellent bleed resistance, as this prevents the substrates from peeling off from each other for a long period of time.

[0141] [Table 1]

Claims

1. A terminal hydroxyethylene-α-olefin copolymer (Z) having a constituent unit (i) derived from ethylene and a constituent unit (ii) derived from α-olefins having 3 to 10 carbon atoms, and satisfying the following requirements (Z1) and (Z2), Adhesive composition containing (meth)acrylic resin (B) and crosslinking agent (C); (Z1) 1 More than 60% of all terminals, excluding the saturated terminal determined by 1H-NMR, contain a hydroxyl group; (Z2) The melting point measured by differential scanning calorimetry (DSC) is not observed.

2. The adhesive composition according to claim 1, wherein the terminal hydroxyethylene-α-olefin copolymer (Z) further satisfies the following requirement (Z3); (Z3) 1 Excluding the saturated end determined by 1H-NMR, more than 60% of all ends contain two or more hydroxyl groups.

3. The adhesive composition according to claim 1, wherein the (meth)acrylic resin (B) satisfies the following (B1) and (B2); (B1) Contains a structural unit derived from a (meth)acrylate having an alkyl group with 1 to 12 carbon atoms, and a structural unit derived from a (meth)acrylate containing a hydroxyl group; (B2) The peak temperature of the loss tangent (tanδ) due to the glass transition temperature, measured by the temperature dependence of dynamic viscoelasticity (frequency 1 Hz, -100 to 200°C), is less than 0°C.

4. The adhesive composition according to claim 1, wherein the terminal hydroxyethylene-α-olefin copolymer (Z) further satisfies the following requirements (Z4) to (Z6); (Z4) The content of component (i) is 30 to 70 mol% and the content of component (ii) is 30 to 70 mol% with respect to a total of 100 mol% of the content of component (i) and component (ii); (Z5) The number-average molecular weight (Mn) obtained by gel permeation chromatography (GPC) and converted to polystyrene equivalent is between 300 and 10000; (Z6) The ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) obtained by gel permeation chromatography (GPC) and converted to polystyrene equivalent (Mw / Mn) is between 1.0 and 5.

0.

5. The adhesive composition according to claim 1, wherein the terminal hydroxyethylene-α-olefin copolymer (Z) further satisfies the following requirement (Z7); (Z7) 1 At least 60% of all terminals, excluding the saturated terminal determined by H-NMR, contain at least the following general formula (1). ―N(-R) 1 -OH)(-R 2 -OH) General formula (1) (In the formula, R 1 , R 2 (It is a divalent organic group with 1 to 6 carbon atoms.)

6. The adhesive composition according to claim 1, wherein the terminal hydroxyethylene-α-olefin copolymer (Z) further satisfies the following requirement (Z8); (Z8) 1 At least 60% of all terminals, excluding saturated terminals determined by H-NMR, contain at least the following general formula (2). -S-CH 2 -R 3 General form (2) (In the formula, R 3 (A hydroxyl group is an organic group that has 2 to 5 hydroxyl groups.)

7. When the sum of the content of the terminal hydroxyethylene α-olefin copolymer (Z), the content of the (meth)acrylic resin (B), and the content of the crosslinking agent (C) is 100% by mass, The amount of the terminal hydroxyethylene α-olefin copolymer (Z) is 0.5% by mass or more and 50% by mass or less. The amount of the (meth)acrylic resin (B) is 47% by mass or more and 99% by mass, The adhesive composition according to claim 1, wherein the amount of the crosslinking agent (C) is 0.5% by mass or more and 5% by mass or less.

8. An adhesive sheet having an adhesive layer formed from the adhesive composition according to any one of claims 1 to 7.

9. A terminal hydroxyethylene-α-olefin copolymer (Z) is produced by reacting an ethylene-α-olefin copolymer (A), which has a constituent unit (i) derived from ethylene and a constituent unit (ii) derived from an α-olefin having 3 to 10 carbon atoms, with a hydroxyl group-containing compound, and satisfies the following requirements (Z1) and (Z2), (Meth)acrylic resin (B) and A method for producing an adhesive composition, comprising the step of mixing with a crosslinking agent (C); (Z1) 1 More than 60% of all terminals, excluding the saturated terminal determined by 1H-NMR, contain a hydroxyl group; (Z2) The melting point measured by differential scanning calorimetry (DSC) is not observed.

10. The manufacturing method according to claim 9, wherein the ethylene-α-olefin copolymer (A) satisfies the following requirements (A1) to (A3); (A1) The content of component (i) is 30 to 70 mol% and the content of component (ii) is 30 to 70 mol% with respect to a total of 100 mol% of the content of component (i) and component (ii); (A2) The number-average molecular weight (Mn) obtained by gel permeation chromatography (GPC) and converted to polystyrene equivalent is 300 to 5,000; (A3) 1 The combined integrated intensity of the vinyl group endpoints and vinylidene group endpoints exceeds 70% of the combined integrated intensity of the signals for vinyl group endpoints, vinylidene group endpoints, disubstituted olefin endpoints, and trisubstituted olefin endpoints determined by 1H-NMR, which is 100%.

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