Adhesive composition, adhesive sheet and electronic device

Abstract

To provide an adhesive composition that can form an adhesive layer having superior water-vapor intrusion barrier performance and superior bubble suppressing performance.SOLUTION: An adhesive composition contains (A) an olefinic polymer having an epoxy group, (B) an olefinic polymer having an acid anhydride group and / or a carboxy group, with a number average molecular weight of 10,000 or more, (C) an olefinic polymer having an acid anhydride group and / or a carboxy group, with a number average molecular weight of less than 10,000, and (D) hygroscopic filler.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive sheet, and an electronic device. [Background technology]

[0002] Adhesive compositions and adhesive sheets having an adhesive layer formed from the adhesive composition are often used for sealing electronic devices such as organic EL devices, solar cells, and sensor devices, and for producing display devices such as liquid crystal displays.

[0003] When sealing electronic devices, it is necessary to form a sealing layer or adhesive layer that has excellent performance in suppressing the intrusion of water vapor (sometimes referred to as "water vapor intrusion barrier performance" in this specification) in order to effectively protect the sealed electronic device.

[0004] Furthermore, when sealing or manufacturing electronic devices or display devices that are used in harsh environments (e.g., high temperature and humidity), it is necessary to form a sealing layer or adhesive layer that has excellent performance in suppressing the generation of bubbles (sometimes referred to as "bubble suppression performance" in this specification) even in harsh environments.

[0005] For example, Patent Document 1 proposes an optical pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer with a specific shear storage modulus and a specific peel distance in a specific constant-load peel test in order to suppress opacity, foaming, etc. of the pressure-sensitive adhesive sheet at high temperatures and high humidity. Also, Patent Document 2 proposes a transparent encapsulant having a specific water absorption rate and a specific haze in order to suppress opacity, foaming, etc. of the encapsulant at high temperatures and high humidity. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-87240 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-207970 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide an adhesive composition capable of forming an adhesive layer having excellent water vapor barrier properties and bubble suppression properties. [Means for solving the problem]

[0008] The present invention that can achieve the above object is as follows. [1] The following components (A) to (D): (A) an olefin polymer having an epoxy group, (B) an olefin polymer having an acid anhydride group and / or a carboxyl group and a number average molecular weight of 10,000 or more; (C) an olefin polymer having an acid anhydride group and / or a carboxy group and a number average molecular weight of less than 10,000; and (D) Hygroscopic filler An adhesive composition comprising: [2] The pressure-sensitive adhesive composition according to the above [1], wherein the component (B) is an olefin polymer having an acid anhydride group and a number-average molecular weight of 10,000 or more. [3] The pressure-sensitive adhesive composition according to [1] or [2], wherein the component (C) is an olefin polymer having an acid anhydride group and a number-average molecular weight of less than 10,000. [4] The adhesive composition according to any one of [1] to [3] above, wherein the number average molecular weight of component (B) is 20,000 to 500,000. [5] The adhesive composition according to any one of [1] to [4], wherein the number average molecular weight of component (C) is 500 or more and less than 10,000. [6] The pressure-sensitive adhesive composition according to any one of the above [1] to [5], further comprising a liquid olefin polymer other than the components (A), (B) and (C). [7] The adhesive composition according to any one of [1] to [6], further comprising a tackifier. [8] A pressure-sensitive adhesive sheet having a laminated structure comprising a support and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of the above [1] to [7]. [9] An electronic device comprising an adhesive layer formed from the adhesive composition according to any one of [1] to [7] above. [Effects of the Invention]

[0009] According to the present invention, it is possible to obtain an adhesive composition capable of forming an adhesive layer having excellent water vapor barrier properties and air bubble suppression properties. DETAILED DESCRIPTION OF THE INVENTION

[0010] adhesive composition The adhesive composition of the present invention is characterized by comprising the following components (A) to (D): (A) an olefin polymer having an epoxy group, (B) an olefin polymer having an acid anhydride group and / or a carboxyl group and a number average molecular weight of 10,000 or more; (C) an olefin polymer having an acid anhydride group and / or a carboxy group and a number average molecular weight of less than 10,000; and (D) Hygroscopic filler.

[0011] By using components (A), (B), and (C), the epoxy groups contained in these components react with the acid anhydride groups and / or carboxyl groups to form a crosslinked structure in the adhesive layer formed from the adhesive composition of the present invention. It is believed that this crosslinked structure allows the resulting adhesive layer to suppress bubble formation even under high temperature and high humidity conditions. In particular, it is believed that the use of component (B) having a number-average molecular weight of 10,000 or more makes it difficult to deform, resulting in an adhesive layer with excellent bubble suppression performance. However, the present invention is not limited to this presumed mechanism.

[0012] Use of component (D) allows the formation of an adhesive layer with excellent water vapor barrier properties. However, when an adhesive layer is formed from an adhesive composition in which component (D) is not sufficiently dispersed, microbubbles are likely to form between the adhesive layer and the adherend when the adhesive layer is laminated onto the adherend. Under high temperature and high humidity, these microbubbles may expand and form larger bubbles. In this regard, in the present invention, by using component (C) having a number-average molecular weight of less than 10,000, it is possible to satisfactorily disperse component (D) in the adhesive composition, and as a result, it is presumed that an adhesive layer with excellent bubble suppression properties can be obtained. However, the present invention is not limited to this presumed mechanism.

[0013] Components (A) to (D) may be used singly or in combination of two or more. Components (A) to (D) will be explained in order below.

[0014] <Component (A)> The component (A) used in the present invention is an olefin polymer having an epoxy group. In this specification, the term "olefin polymer" refers to a polymer having a structural unit derived from an olefin (hereinafter referred to as "olefin"). The term "polymer" refers to a polymer in which olefin units (sometimes abbreviated as "olefin units") are the main structural units (i.e., the amount of olefin units is the largest among all structural units). Note that, hereinafter, "structural units derived from butene" which are olefin units will sometimes be abbreviated as "butene units".

[0015] The olefin polymer may be an olefin resin (e.g., a propylene-butene copolymer) or an olefin rubber (e.g., a butyl rubber, i.e., an isobutene-isoprene copolymer). In this specification, "olefin resin" means an olefin polymer that cannot form a rubber elastomer by crosslinking, and "olefin rubber" means an olefin polymer that can form a rubber elastomer by crosslinking.

[0016] The olefin is preferably a monoolefin having one olefinic carbon-carbon double bond and / or a diolefin having two olefinic carbon-carbon double bonds. Examples of monoolefins include α-olefins such as ethylene, propylene, 1-butene, isobutene (isobutylene), 1-pentene, 1-hexene, 1-heptene, and 1-octene. Examples of diolefins include 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethylbutadiene.

[0017] The olefin-based polymer may be a homopolymer or a copolymer. The copolymer may be a random copolymer or a block copolymer. The olefin-based polymer may also be a copolymer of an olefin and a monomer other than an olefin. Examples of the olefin-based copolymer include an ethylene-non-conjugated diene copolymer, an ethylene-propylene copolymer, an ethylene-propylene-non-conjugated diene copolymer, an ethylene-butene copolymer, a propylene-butene copolymer, a propylene-butene-non-conjugated diene copolymer, an isobutene-isoprene copolymer, a styrene-isobutene copolymer, and a styrene-isobutene-styrene copolymer.

[0018] The epoxy group concentration in component (A) is preferably 0.1 to 5 mmol / g, more preferably 0.3 to 3 mmol / g, from the viewpoint of achieving a more appropriate range for the crosslink density of the adhesive layer and a balance between suppressing bubble generation and adhesiveness. The epoxy group concentration is determined from the epoxy equivalent obtained in accordance with JIS K 7236-1995.

[0019] The number-average molecular weight of component (A) is preferably 10,000 to 500,000, more preferably 30,000 to 400,000, and even more preferably 50,000 to 300,000, from the viewpoint of ensuring a more appropriate range of fluidity for the adhesive composition and achieving a balance between suppressing bubble generation and adhesiveness. The number-average molecular weight of each component is measured by gel permeation chromatography (GPC) (polystyrene equivalent). Specifically, the number-average molecular weight measured by GPC is measured using a Shimadzu LC-9A / RID-6A measuring instrument, a Showa Denko Shodex K-800P / K-804L / K-804L column, toluene, or the like, as the mobile phase, at a column temperature of 40°C, and can be calculated using a calibration curve for standard polystyrene.

[0020] Component (A) can be obtained, for example, by graft-modifying an olefin polymer with an unsaturated compound having an epoxy group (e.g., glycidyl (meth)acrylate, 4-hydroxybutyl acrylate glycidyl ether, allyl glycidyl ether) under radical reaction conditions.

[0021] As component (A), for example, polymers available from Seiko PMC Co., Ltd. can be used. Examples of such polymers available from Seiko PMC include "ER829" (glycidyl methacrylate-modified propylene-butene random copolymer), "ER850" (glycidyl methacrylate-modified butyl rubber), and "ER853" (glycidyl methacrylate-modified butyl rubber). propylene-butene random copolymer), "ER866" (glycidyl methacrylate-modified butyl rubber), "T-YP276" (glycidyl methacrylate-modified propylene-butene random copolymer), "T-YP313" (glycidyl methacrylate-modified propylene-butene random copolymer), etc.

[0022] Component (A) is preferably a propylene-butene copolymer having epoxy groups and / or an isobutene-isoprene copolymer having epoxy groups (i.e., butyl rubber), and more preferably a propylene-butene copolymer having epoxy groups or an isobutene-isoprene copolymer having epoxy groups.

[0023] An adhesive layer obtained by using a propylene-butene copolymer with low crystallinity as component (A) tends to have a low adhesiveness even when stored at high temperature and high humidity. Therefore, when a propylene-butene copolymer having epoxy groups is used as component (A), in order to reduce the crystallinity of the copolymer, the amount of butene units in the copolymer is preferably 5 to 70 mass%, more preferably 10 to 60 mass%, and even more preferably 20 to 50 mass% based on the total of propylene units and butene units. The amount of butene units is based on the propylene units and butene units excluding modified portions (e.g., portions derived from glycidyl (meth)acrylate for introducing epoxy groups).

[0024] When an isobutene-isoprene copolymer having an epoxy group (i.e., butyl rubber) is used as component (A), the amount of isoprene units in the copolymer is preferably 0.1 to 10 mass%, more preferably 0.3 to 5 mass%, and even more preferably 0.5 to 3 mass% based on the total of isobutene units and isoprene units, from the viewpoint of moisture resistance of the adhesive layer. The amount of isoprene units is based on the isobutene units and isoprene units excluding modified portions (for example, portions derived from glycidyl (meth)acrylate for introducing epoxy groups).

[0025] The total content of component (A) and component (B), which will be described later, is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, based on the nonvolatile content excluding component (D) of the adhesive composition, from the viewpoint of suppressing bubble generation, and is preferably 80% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 50% by mass or less, based on the viewpoint of adhesiveness. Here, "the total content of components (A) and (B) based on the nonvolatile content excluding component (D) of the adhesive composition" means "100 × (mass of component (A) + mass of component (B)) / (mass of nonvolatile content of adhesive composition - mass of component (D))".

[0026] In order to form a more appropriate crosslinked structure, the mass ratio of component (A) to component (B) (component (A):component (B)) is preferably 5:95 to 95:5, more preferably 10:90 to 90:10, and even more preferably 80:20 to 20:80.

[0027] <(B) component> The component (B) used in the present invention is an olefin polymer having an acid anhydride group (i.e., a carbonyloxycarbonyl group (—CO—O—CO—)) and / or a carboxy group and a number average molecular weight of 10,000 or more, preferably an olefin polymer having an acid anhydride group and a number average molecular weight of 10,000 or more. The explanations and examples of “olefin” and “olefin polymer” in the component (B) are the same as those in the component (A).

[0028] When an olefin polymer having an acid anhydride group and a number average molecular weight of 10,000 or more is used as component (B), the concentration of the acid anhydride group in the polymer is preferably 0.1 to 1.5% by weight, from the viewpoint of setting the crosslink density of the adhesive layer in a more appropriate range and achieving a balance between suppressing bubble generation and adhesiveness. The concentration of the acid anhydride group is determined from the acid value, which is defined as the number of milligrams of potassium hydroxide required to neutralize the acid present in 1 g of the polymer, according to JIS K 2501.

[0029] When an olefin polymer having carboxy groups and a number average molecular weight of 10,000 or more is used as component (B), the concentration of carboxy groups in the polymer is preferably 0.1 to 5 mmol / g, more preferably 0.2 to 3 mmol / g, from the viewpoint of balancing bubble suppression and adhesiveness. The concentration of carboxy groups is obtained from the acid value, which is defined as the number of milligrams of potassium hydroxide required to neutralize the acid present in 1 g of polymer, as described in JIS K 2501.

[0030] When an olefin polymer having an acid anhydride group and a carboxy group and a number average molecular weight of 10,000 or more is used as component (B), the sum of the concentration of the acid anhydride group and the concentration of the carboxy group in the polymer is preferably 0.1 to 5 mmol / g, more preferably 0.2 to 3 mmol / g, from the viewpoint of achieving a balance between suppressing bubble generation and adhesiveness.

[0031] The number average molecular weight of component (B) is preferably 20,000 to 500,000, more preferably 25,000 to 400,000, and even more preferably 30,000 to 300,000, from the viewpoint of providing a more appropriate range for the fluidity of the adhesive composition and achieving a balance between suppressing bubble generation and adhesiveness.

[0032] Component (B) can be produced, for example, by graft-modifying an olefin polymer with an unsaturated compound having an acid anhydride group and / or a carboxy group (for example, maleic anhydride) under radical reaction conditions.

[0033] As component (B), for example, a polymer available from Seiko PMC Co., Ltd. Examples of such polymers available from Seiko PMC Co., Ltd. include "ER641" (maleic anhydride-modified butyl rubber), "ER645" (maleic anhydride-butyl methacrylate random copolymer-modified propylene-butene random copolymer), "ER661" (maleic anhydride-butyl methacrylate random copolymer-modified butyl rubber), "ER669" (maleic anhydride-2-ethylhexyl acrylate random copolymer-modified butyl rubber), and "ER674" (maleic anhydride-lauryl methacrylate random copolymer-modified butyl rubber).

[0034] In one embodiment of the present invention, component (B) is (i) Preferably, the copolymer is a propylene-butene copolymer having an acid anhydride group and / or a carboxy group and having a number average molecular weight of 10,000 or more, and / or an isobutene-isoprene copolymer having an acid anhydride group and / or a carboxy group and having a number average molecular weight of 10,000 or more (i.e., butyl rubber), (ii) More preferably, it is a propylene-butene copolymer having an acid anhydride group and / or a carboxy group and a number average molecular weight of 10,000 or more, or an isobutene-isoprene copolymer having an acid anhydride group and / or a carboxy group and a number average molecular weight of 10,000 or more, (iii) More preferably, it is a propylene-butene copolymer having an acid anhydride group and a number average molecular weight of 10,000 or more, or an isobutene-isoprene copolymer having an acid anhydride group and a number average molecular weight of 10,000 or more.

[0035] The adhesive layer obtained by using a propylene-butene copolymer with low crystallinity as the component (B) tends to be less susceptible to deterioration in adhesion even when stored at high temperature and humidity. Therefore, the adhesive layer having an acid anhydride group and / or a carboxyl group (preferably an acid anhydride group) as the component (B), and When a propylene-butene copolymer having a number average molecular weight of 10,000 or more is used, the amount of butene units in the copolymer is preferably 5 to 70 mass%, more preferably 10 to 60 mass%, and even more preferably 20 to 50 mass%, based on the total of propylene units and butene units, in order to reduce the crystallinity of the copolymer. The amount of butene units is based on the propylene units and butene units excluding modified portions (for example, portions derived from maleic anhydride for introducing acid anhydride groups, portions derived from maleic anhydride-(meth)acrylate copolymers, etc.).

[0036] When an isobutene-isoprene copolymer (i.e., butyl rubber) having an acid anhydride group and / or a carboxyl group (preferably an acid anhydride group) and a number average molecular weight of 10,000 or more is used as component (B), the amount of isoprene units in the copolymer is preferably 0.1 to 5 mass%, more preferably 0.2 to 3 mass%, based on the total of isobutene units and isoprene units, from the viewpoint of moisture resistance of the adhesive layer. The amount of isoprene units is based on the isobutene units and isoprene units excluding modified portions (e.g., portions derived from maleic anhydride, portions derived from maleic anhydride-(meth)acrylate copolymers, etc., for introducing acid anhydride groups).

[0037] <(C) component> The component (C) used in the present invention is an olefin polymer having an acid anhydride group (i.e., a carbonyloxycarbonyl group (—CO—O—CO—)) and / or a carboxy group and a number average molecular weight of less than 10,000, preferably an olefin polymer having an acid anhydride group and a number average molecular weight of less than 10,000. The description and examples of the olefin polymer in component (C) are the same as those for component (A).

[0038] When an olefin polymer having an acid anhydride group and a number average molecular weight of less than 10,000 is used as component (C), the concentration of the acid anhydride group in the polymer is preferably 0.1 to 3 mmol / g, more preferably 0.2 to 2 mmol / g, from the viewpoint of dispersing component (D) and suppressing the generation of bubbles. The concentration of the acid anhydride group is obtained from the acid value, which is defined as the number of milligrams of potassium hydroxide required to neutralize the acid present in 1 g of polymer, according to JIS K 2501.

[0039] When an olefin polymer having carboxy groups and a number average molecular weight of less than 10,000 is used as component (C), the concentration of carboxy groups in the polymer is preferably 0.1 to 3 mmol / g, more preferably 0.2 to 2 mmol / g, from the viewpoint of dispersing component (D) and suppressing bubble formation. The concentration of carboxy groups is obtained from the acid value, which is defined as the number of milligrams of potassium hydroxide required to neutralize the acid present in 1 g of polymer, as described in JIS K 2501.

[0040] When an olefin polymer having an acid anhydride group and a carboxy group and a number average molecular weight of less than 10,000 is used as component (C), the sum of the concentration of the acid anhydride group and the concentration of the carboxy group in the polymer is preferably 0.1 to 3 mmol / g, more preferably 0.2 to 2 mmol / g, from the viewpoints of dispersing component (D) and suppressing the generation of bubbles.

[0041] From the viewpoint of dispersibility of component (D), the number average molecular weight of component (C) is preferably 500 or more and less than 10,000, more preferably 700 to 8,000, and even more preferably 1,000 to 6,000.

[0042] The component (C) can be produced, for example, by graft-modifying an olefin polymer with an unsaturated compound having an acid anhydride group and / or a carboxy group (for example, maleic anhydride) under radical reaction conditions.

[0043] Polymers available from manufacturers can be used as component (C). Examples of such polymers include "HV-300M" (maleic anhydride-modified liquid polybutene) manufactured by Toho Chemical Industry Co., Ltd., "ER688" (maleic anhydride-butyl methacrylate random copolymer-modified polybutene) manufactured by Seiko PMC Corporation, and "Lucant A-5515" (acid-modified ethylene-α-olefin copolymer), "Lucant A-5260" (acid-modified ethylene-α-olefin copolymer), and "Lucant A-5320H" (acid-modified ethylene-α-olefin copolymer) manufactured by Mitsui Chemicals, Inc.

[0044] In one embodiment of the present invention, component (C) is preferably a polybutene having an acid anhydride group and / or a carboxy group and having a number average molecular weight of less than 10,000, and more preferably a polybutene having an acid anhydride group and having a number average molecular weight of less than 10,000.

[0045] The content of the (C) component is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of the (D) component, from the viewpoint of dispersing the (D) component; and from the viewpoint of suppressing bubbles, the content is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less.

[0046] <Amount of component (A), and amounts of components (B) and (C) used> The amounts of component (A) used and the amounts of components (B) and (C) used are preferably determined by the ratio of the functional groups they contain. From the viewpoint of suppressing bubbles due to crosslinking, the ratio of "the amount (mol) of epoxy groups contained in component (A)" to "the total amount (mol) of acid anhydride groups and the total amount (mol) of carboxy groups contained in components (B) and (C)" is preferably 20:80 to 80:20, more preferably 25:75 to 75:25, and even more preferably 30:70 to 70:30. Note that, for example, when component (B) and component (C) both contain only acid anhydride groups, the above-mentioned "total amount (mol) of acid anhydride groups and the total amount (mol) of carboxy groups" means "the total amount (mol) of acid anhydride groups."

[0047] <(D) component> The component (D) used in the present invention is a hygroscopic filler. Examples of the component (D) include uncalcined hydrotalcite, semi-calcined hydrotalcite, calcined hydrotalcite, calcium oxide, magnesium oxide, calcined dolomite (a mixture containing calcium oxide and magnesium oxide), calcium hydride, strontium oxide, aluminum oxide, barium oxide, molecular sieve, and silica. The component (D) is preferably semi-calcined hydrotalcite and / or calcium oxide, and more preferably semi-calcined hydrotalcite or calcium oxide.

[0048] Hydrotalcite can be classified into uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite.

[0049] Uncalcined hydrotalcite is, for example, natural hydrotalcite (MgAl(OH) 16 It is a metal hydroxide with a layered crystal structure, such as the basic skeleton layer [Mg 1-X Al X (OH)2] X+ and the intermediate layer [(CO3) X / 2 mH2O] X- The uncalcined hydrotalcite is a concept that includes hydrotalcite-like compounds such as synthetic hydrotalcite. Examples of hydrotalcite-like compounds include those represented by the following formula (I) and formula (II).

[0050] [M 2+ 1-x M 3+ x (OH)2] x+ ·[(A n- ) x / n mH2O] x- (I) (In the formula, M 2+ is Mg 2+ , Zn 2+represents a divalent metal ion such as, M 3+ is Al 3+ Fe 3+ etc., represents a trivalent metal ion such as, A n- is CO3 2- Cl - NO3 - etc., represents an n-valent anion, 0 < x < 1, 0 ≦ m < 1, and n is a positive number.) In formula (I), M 2+ is preferably Mg 2+ and M 3+ is preferably Al 3+ and A n- is preferably CO3 2- is.)

[0051] M 2+ x Al2(OH) 2x+6-nz (A n- ) z ·mH2O (II) [[ID=​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​On the other hand, calcined hydrotalcite is obtained by calcining uncalcined or semi-calcined hydrotalcite, and refers to a metal oxide having an amorphous structure in which not only interlayer water but also hydroxyl groups have disappeared through condensation dehydration.

[0054] Uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite can be distinguished by their saturated water absorption. The saturated water absorption of semi-calcined hydrotalcite is 1% by mass or more and less than 20% by mass. On the other hand, the saturated water absorption of uncalcined hydrotalcite is less than 1% by mass, and the saturated water absorption of calcined hydrotalcite is 20% by mass or more.

[0055] The "saturated water absorption" refers to the rate of mass increase relative to the initial mass when 1.5 g of a measurement sample (for example, semi-calcined hydrotalcite) is weighed out on a balance, the initial mass is measured, and the sample is allowed to stand for 200 hours in a small environmental test chamber (SH-222 manufactured by Espec Corporation) set at atmospheric pressure, 60°C, and 90% RH (relative humidity), and is calculated using the following formula (i): Saturated water absorption rate (mass%) = 100 × (mass after moisture absorption – initial mass) / initial mass (i) It can be found by:

[0056] The saturated water absorption of the semi-calcined hydrotalcite is preferably 3% by mass or more and less than 20% by mass, and more preferably 5% by mass or more and less than 20% by mass.

[0057] Furthermore, uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite can be distinguished by the rate of weight loss on heat measured by thermogravimetric analysis. The rate of weight loss on heat of semi-calcined hydrotalcite at 280°C is less than 15% by mass, and the rate of weight loss on heat of semi-calcined hydrotalcite at 380°C is 12% by mass or more. On the other hand, the rate of weight loss on heat of uncalcined hydrotalcite at 280°C is 15% by mass or more, and the rate of weight loss on heat of calcined hydrotalcite at 380°C is less than 12% by mass.

[0058] Thermogravimetric analysis was performed using a Hitachi High-Tech Science TG / DTA EXSTAR6300. 5 mg of hydrotalcite was weighed into an aluminum sample pan, and the pan was left open without a lid and heated from 30°C to 550°C at a rate of 200 mL / min under a nitrogen atmosphere. The thermal weight loss rate can be calculated using the following formula (ii): Thermogravimetric reduction rate (mass%) = 100 × (mass before heating - mass when reaching the specified temperature) / mass before heating (ii).

[0059] Uncalcined hydrotalcite, semi-calcined hydrotalcite, and calcined hydrotalcite can be distinguished by the peaks and relative intensity ratios measured by powder X-ray diffraction. Semi-calcined hydrotalcite exhibits a split peak or a peak with a shoulder formed by combining two peaks in powder X-ray diffraction at 2θ of approximately 8 to 18°. The relative intensity ratio (low-angle diffraction intensity / high-angle diffraction intensity) between the diffraction intensity of the peak or shoulder appearing on the low-angle side (= low-angle diffraction intensity) and the diffraction intensity of the peak or shoulder appearing on the high-angle side (= high-angle diffraction intensity) is 0.001 to 1,000. Uncalcined hydrotalcite, on the other hand, has only one peak near 8 to 18°, or the relative intensity ratio between the diffraction intensity of the peak or shoulder appearing on the low-angle side and the peak or shoulder appearing on the high-angle side falls outside the aforementioned range. Calcined hydrotalcite does not have a characteristic peak in the 8 to 18° region, but has a characteristic peak at 43°. Powder X-ray diffraction measurements were performed using a powder X-ray diffractometer (PANalytical, Empyrean) with a CuK anticathode. The diffraction angle range (2θ) was 5.0131 to 79.9711°, with an α of 1.5405 Å, voltage of 45 V, current of 40 mA, sampling width of 0.0260°, scan rate of 0.0657° / s, and diffraction angle range (2θ) of 5.0131 to 79.9711°. Peak search was performed using the peak search function of the software provided with the diffractometer, with the following conditions: minimum significance: 0.50, minimum peak tip: 0.01°, maximum peak tip: 1.00°, peak base width: 2.00°, and method: minimum value of second derivative.

[0060] The BET specific surface area of ​​semi-calcined hydrotalcite is 1 to 250 m 2 / g is preferred, and 5 to 200m 2 These BET specific surface areas are measured according to the BET method using a specific surface area measuring device (Macsorb HM Model 1210, manufactured by Mountec Co., Ltd.). Nitrogen gas is adsorbed onto the sample surface, and the BET multipoint method can be used to calculate the surface area.

[0061] The particle size of the semi-calcined hydrotalcite is preferably 1 to 1,000 nm, more preferably 10 to 800 nm. These particle sizes are the median sizes of the particle size distribution determined on a volume basis by laser diffraction / scattering particle size distribution measurement (JIS Z 8825).

[0062] The semi-calcined hydrotalcite can be surface-treated with a surface treatment agent. Examples of the surface treatment agent that can be used for the surface treatment include higher fatty acids, alkylsilanes, and silane coupling agents, with higher fatty acids and alkylsilanes being preferred. One or more types of surface treatment agents can be used.

[0063] Commercially available semi-calcined hydrotalcites can be used, such as "DHT-4C" and "DHT-4A-2" manufactured by Kyowa Chemical Industry Co., Ltd.

[0064] Commercially available calcium oxide products can be used, such as "QC-X" manufactured by Inoue Lime Industry Co., Ltd., "Moistop #10" manufactured by Sankyo Flour Milling Co., Ltd., "HAL-G," "HAL-J," and "HAL-F" manufactured by Yoshizawa Lime Industry Co., Ltd., and "CaO Nano Powder" manufactured by Filgen.

[0065] The particle size of calcium oxide and the particle size of the mixture containing calcium oxide are each preferably 0.03 to 10 μm, more preferably 0.05 to 5 μm, and even more preferably 0.1 to 3 μm. These particle sizes are the median diameters of the particle size distribution obtained by laser diffraction / scattering particle size distribution measurement (JIS Z 8825) on a volume basis.

[0066] The content of component (D) relative to the nonvolatile content of the adhesive composition is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, from the viewpoint of the water vapor barrier performance of the adhesive layer, and is preferably 75% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less, from the viewpoint of the adhesion of the adhesive layer. Here, "the content of component (D) relative to the nonvolatile content of the adhesive composition" means "100 × mass of component (D) / mass of nonvolatile content of the adhesive composition."

[0067] <Other ingredients> The adhesive composition of the present invention may contain components other than components (A) to (D) (hereinafter, sometimes referred to as "other components"), as long as the effects of the present invention are not impaired. Examples of other components include liquid olefin polymers, tackifiers, antioxidants, metal complexes, curing agent accelerators, etc. These may be used alone or in combination of two or more. The liquid olefin polymers, etc. will be described below in order.

[0068] (liquid olefin polymer) In the present invention, a liquid olefin polymer other than components (A), (B), and (C) may be used to improve the tackiness of the adhesive layer and its adhesion. In the present invention, the term "liquid" in "liquid olefin polymer" means that the viscosity at 25°C is 5,000 Pa·s or less. Furthermore, in the present invention, the term "viscosity at 25°C" means the viscosity calculated by multiplying the dynamic viscosity at 25°C measured with a dynamic viscoelasticity measuring device by the density. Examples of dynamic viscoelasticity measuring devices include a rheometer (trade name: DISCOVERY HR-2) manufactured by TA Instruments. The explanations and examples of "olefin" and "olefin polymer" in "liquid olefin polymer" are the same as those for component (A).

[0069] In the present invention, a liquid olefin polymer having an epoxy group is classified as component (A), and a liquid olefin polymer having an acid anhydride group and / or a carboxy group is classified as component (B) or component (C) depending on its number average molecular weight.

[0070] The viscosity of the liquid olefin polymer at 25° C. is preferably 50 to 5,000 Pa·s, more preferably 100 to 4,000 Pa·s, and even more preferably 200 to 3,000 Pa·s, from the viewpoint of improving the adhesiveness of the adhesive layer.

[0071] The number average molecular weight of the liquid polyolefin polymer is preferably 100 to 50,000, more preferably 200 to 30,000, and even more preferably 300 to 20,000, from the viewpoint of improving the adhesiveness of the adhesive layer.

[0072] Commercially available liquid olefin polymers can be used. Examples of such commercially available products include ENEOS "HV-300" (liquid polybutene), ENEOS "HV-1900" (liquid polybutene), ENEOS "HV-50" (liquid polybutene), ENEOS "HV-35" (liquid polybutene), Kothari "950MW" (liquid polybutene), Kothari "2400MW" (liquid olefin polymer), INEOS "H-1900" (liquid polybutene), and INEOS "HV-500" (liquid polybutene). "H-6000" (liquid polybutene), INEOS "H-18000" (liquid polybutene), NOF Corporation "200N" (liquid polybutene), Nippon Soda Co., Ltd. "BI-2000" (hydrogenated polybutadiene), Nippon Soda Co., Ltd. "BI-3000" (hydrogenated polybutadiene), Nippon Soda Co., Ltd. "GI-3000" (hydrogenated polybutadiene), Mitsui Chemicals Inc. "Lucant LX100" (liquid olefin polymer), Mitsui Chemicals Inc. "Lucant LX400" (liquid olefin Idemitsu Showa Shell Co., Ltd. "Poly bd R-45HT" (butadiene-based liquid rubber), Idemitsu Showa Shell Co., Ltd. "Poly bd R-15HT" (butadiene-based liquid rubber), Idemitsu Showa Shell Co., Ltd. "Poly ip" (liquid polyisoprene), Nippon Soda's "B-1000" (liquid polybutadiene), Nippon Soda's "B-3000" (liquid polybutadiene), Nippon Soda's "G-3000" (liquid polybutadiene), Kuraray's "LIR-30" (liquid polyisoprene), Kuraray's "LIR-390" (liquid polyisoprene), Kuraray's "LIR-290" (liquid polyisoprene), Kuraray's "LBR-302" (liquid polybutadiene), Kuraray's "LBR-305" (liquid polybutadiene), Kuraray's "LBR-361" (liquid polybutadiene), Kuraray's "L-SBR-820" (liquid styrene-butadiene random copolymer), CRAY VALLEY's "Ricon154" (liquid butadiene), CRAY Examples include "RICON 184" (liquid styrene-butadiene random copolymer) manufactured by Valley.

[0073] The liquid olefin polymer is preferably liquid polybutene. When a liquid olefin polymer is used, its content in the adhesive composition is preferably 5 to 70 mass %, more preferably 10 to 60 mass %, and even more preferably 15 to 50 mass %, based on the non-volatile content of the adhesive composition excluding component (D), from the viewpoint of adhesion of the adhesive layer. Here, "the content of the liquid olefin polymer relative to the non-volatile content of the adhesive composition excluding component (D)" means "100 × mass of the liquid olefin polymer / (mass of the non-volatile content of the adhesive composition - mass of component (D))". "The content of components other than the liquid olefin polymer relative to the non-volatile content of the adhesive composition excluding component (D)" has the same meaning as "the content of the liquid olefin polymer relative to the non-volatile content of the adhesive composition excluding component (D)".

[0074] (tackifier) The tackifier is a component that imparts tackiness to the adhesive composition. Examples of the tackifier include rosin resins, terpene resins, modified terpene resins (hydrogenated terpene resins, terpene-phenol copolymer resins, aromatic modified terpene resins, etc.), petroleum resins (aliphatic petroleum resins, hydrogenated petroleum resins, alicyclic petroleum resins, aromatic petroleum resins, copolymerized petroleum resins), coumarone-indene resins, alkylphenol resins, and xylene resins.

[0075] Commercially available tackifiers can be used. Examples of commercially available tackifiers include the following: Rosin-based resins include Pine Crystal ME-H, Pine Crystal ME-D, Pine Crystal ME-G, Pine Crystal KR-85, Pine Crystal KE-311, Pine Crystal KE-359, Pine Crystal D-6011, Pine Crystal PE-590, Pine Crystal KE-604, Pine Crystal PR-580 (all manufactured by Arakawa Chemical Industries, Ltd.), etc.

[0076] Examples of terpene resins include YS Resin PX1000, YS Resin PX1150, YS Resin PX1150N, YS Resin PX1250, YS Resin TH130, YS Resin TR105, YS Resin LP, and YS Resin CP (all manufactured by Yasuhara Chemical Co., Ltd.).

[0077] Examples of hydrogenated terpene resins include Clearon P, Clearon M, and Clearon K series (all manufactured by Yasuhara Chemical Co., Ltd.).

[0078] Examples of terpene phenol copolymer resins include YS Polystar 2000, Polystar U, Polystar T, Polystar S, and Mighty Ace G (all manufactured by Yasuhara Chemical Co., Ltd.).

[0079] Examples of aromatic modified terpene resins include YS Resin TO85 and YS Resin TO105. , YS Resin TO115, and YS Resin TO125 (all manufactured by Yasuhara Chemical Co., Ltd.).

[0080] Examples of hydrogenated petroleum resins include Escorez 5300 series and 5600 series (all manufactured by Exxon Mobil Corporation); T-REZ OP501, T-REZ PR803, T-REZ HA085, T-REZ HA103, T-REZ HA105, and T-REZ HA125 (all hydrogenated dicyclopentadiene-based petroleum resins, manufactured by ENEOS Corporation); Quintone 1325 and Quintone 1345 (all manufactured by Zeon Corporation); Imarv S-100, Imarv S-110, Imarv P-100, Imarv P-125, and Imarv P-140 (all hydrogenated dicyclopentadiene-based petroleum resins, manufactured by Idemitsu Kosan Co., Ltd.); Arcon P-90, Arcon P-100, Arcon P-115, Arcon P-125, Arcon P-140, and Arcon M-90, Alcon M-100, Alcon M-115, Alcon M-135, TFS13-030 (all manufactured by Arakawa Chemical Industries, Ltd.), etc.

[0081] Examples of aromatic petroleum resins include ENDEX 155 (manufactured by Eastman Co.); Neopolymer L-90, Neopolymer 120, Neopolymer 130, Neopolymer 140, Neopolymer 150, Neopolymer 170S, Neopolymer 160, Neopolymer E-100, Neopolymer E-130, Neopolymer M-1, Neopolymer S, Neopolymer S100, Neopolymer 120S, Neopolymer 130S, and Neopolymer EP-140 (all manufactured by ENEOS Corporation); Petokol LX, Petokol 120, Petokol 130, and Petokol 140 (all manufactured by Tosoh Corporation); and T-REZ RB093, T-REZ RC100, T-REZ RC115, T-REZ RC093, and T-REZ RE100 (all manufactured by ENEOS Corporation).

[0082] Examples of copolymer petroleum resins include T-REZ HB103, T-REZ HB125, T-REZ PR801, T-REZ PR802, and T-REZ RD104 (all manufactured by ENEOS Corporation); Petrotack 60, Petrotack 70, Petrotack 90, Petrotack 90HS, Petrotack 90V, and Petrotack 100V (all manufactured by Tosoh Corporation); and Quintone D100 (manufactured by Zeon Corporation).

[0083] From the viewpoint of the heat resistance of the adhesive composition, the softening point of the tackifier is preferably 50 to 200° C., more preferably 90 to 180° C., and even more preferably 100 to 150° C. The softening point is measured by the ring and ball method in accordance with JIS K2207.

[0084] When a tackifier is used, its content in the adhesive composition is preferably 2 to 70 mass %, more preferably 5 to 60 mass %, and even more preferably 10 to 50 mass %, based on the non-volatile content of the adhesive composition excluding component (D), from the viewpoint of adhesion of the adhesive layer.

[0085] (antioxidant) In the present invention, the antioxidant is not particularly limited, and known antioxidants can be used. When an antioxidant is used, the content thereof is preferably 0.05 to 5 mass %, more preferably 0.10 to 4 mass %, and even more preferably 0.20 to 3 mass %, based on the nonvolatile content of the adhesive composition excluding component (D).

[0086] (metal complexes) In order to disperse component (D) better in the composition, a metal complex may be used in which a bidentate ligand in which both coordinating atoms are oxygen atoms (hereinafter sometimes referred to as an "oxygen-bidentate ligand") and a monodentate ligand in which the coordinating atom is an oxygen atom (hereinafter sometimes referred to as an "oxygen-monodentate ligand") are bonded to a central metal.

[0087] The metal complex is preferably represented by the following formula (1):

[0088] [ka]

[0089] [In formula (1), M represents a divalent or higher metal; R1 and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkenyloxy group, an aryl group, or an aralkyl group; R2 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an alkenyloxy group, an alkoxycarbonyl group, an aryl group, or an aralkyl group; X represents a monodentate ligand; In formula (1), the solid line between the oxygen atom (O) in [ ] and M represents a covalent bond. The dashed line between the oxygen atom (O) and M in [ ] in formula (1) represents a coordinate bond, and m represents 3 or 4, n represents an integer of 0 to 4, and m≧n. The metal complex (1) may be used alone or in combination of two or more kinds thereof.

[0090] M in the above formula (1) is preferably a metal of Group 4 of the periodic table or a metal of Group 13 of the periodic table, and more preferably aluminum, titanium or zirconium.

[0091] In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0092] In this specification, the alkyl group may be either linear or branched. The number of carbon atoms in the alkyl group (excluding the alkyl group in the long-chain alkyl (meth)acrylate) is preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 6. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a 1-ethylpropyl group, a hexyl group, an isohexyl group, a 1,1-dimethylbutyl group, a 2,2-dimethylbutyl group, a 3,3-dimethylbutyl group, and a 2-ethylbutyl group. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, and an amino group which may have a substituent.

[0093] In this specification, the alkenyl group may be either linear or branched. The number of carbon atoms in the alkenyl group is preferably 2 to 20. Examples of the alkenyl group include ethenyl (i.e., vinyl), 1-propenyl, 2-propenyl, 2-methyl-1-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 3-methyl-2-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 4-methyl-3-pentenyl, 1-hexenyl, 3-hexenyl, and 5-hexenyl. The alkenyl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, and an amino group that may have a substituent.

[0094] In this specification, the alkynyl group may be either linear or branched. The number of carbon atoms in the alkynyl group is preferably 2 to 10, more preferably 2 to 6. Examples of the alkynyl group include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, a 1-pentynyl group, a 2-pentynyl group, a 3-pentynyl group, a 4-pentynyl group, a 1-hexynyl group, a 2-hexynyl group, a 3-hexynyl group, a 4-hexynyl group, a 5-hexynyl group, and a 4-methyl-2-pentynyl group. The alkynyl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, and an amino group which may have a substituent.

[0095] In this specification, the number of carbon atoms in the aryl group is preferably 6 to 18, more preferably 6 to 14. Examples of the aryl group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthryl group, and a 9-anthryl group. The aryl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, and an amino group which may have a substituent.

[0096] In this specification, the number of carbon atoms in the aralkyl group is preferably 7 to 16. Examples of the aralkyl group include a benzyl group, a phenethyl group, a naphthylmethyl group, and a phenylpropyl group. The aralkyl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, and an amino group which may have a substituent.

[0097] In this specification, examples of the amino group which may have a substituent include an amino group, a mono- or di-alkylamino group (e.g., a methylamino group, a dimethylamino group, an ethylamino group, a diethylamino group, a propylamino group, a dibutylamino group), a mono- or di-cycloalkylamino group (e.g., a cyclopropylamino group, a cyclohexylamino group), a mono- or di-arylamino group (e.g., a phenylamino group), a mono- or di-aralkylamino group (e.g., a benzylamino group, a dibenzylamino group), a heterocyclic amino group (e.g., a pyridylamino group), and the like.

[0098] In this specification, the explanation of the alkyl group in the alkoxy group (i.e., alkyloxy group) is the same as the explanation of the alkyl group described above. The alkoxy group may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, and an amino group which may have a substituent.

[0099] In this specification, the alkenyl group in the alkenyloxy group is the same as the above-mentioned alkenyl group. The alkenyloxy group may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, and an amino group which may have a substituent.

[0100] In this specification, the alkyl group in the alkoxycarbonyl group (i.e., alkyloxycarbonyl group) is the same as the alkyl group described above. The alkoxycarbonyl group may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, and an amino group which may have a substituent.

[0101] The monodentate ligand represented by X in formula (1) is, for example, an alkoxide anion (RO - ) (wherein R represents an organic group), carboxylate anion (RCOO - ) (wherein R represents an organic group), oxo (O), and the like.

[0102] The alkoxide anion is RO- (wherein R represents an organic group). The organic group R may be either an aliphatic group or an aromatic group. The aliphatic group may be either a saturated aliphatic group or an unsaturated aliphatic group. The number of carbon atoms in the organic group R is preferably 1 to 20, more preferably 6 to 18, and particularly preferably 8 to 14. The alkoxide anion (RO - ) include, for example, methoxide, ethoxide, propoxide, isopropoxide, butoxide, isobutoxide, sec-butoxide, tert-butoxide, pentyl oxide, hexyl oxide, phenoxide, 4-methylphenoxide, and the like.

[0103] The carboxylate anion is RCOO - (wherein R represents an organic group). The organic group R may be either an aliphatic group or an aromatic group. The aliphatic group may be either a saturated aliphatic group or an unsaturated aliphatic group. The number of carbon atoms in the organic group R is preferably 1 to 20, more preferably 6 to 18, and particularly preferably 8 to 14. The carboxylate anion (RCOO - ) include, for example, carboxylate anions corresponding to carboxylic acids such as acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, octylic acid, nonanoic acid, decanoic acid, dodecanoic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and benzoic acid.

[0104] In formula (1), the brackets [ ] represent a polydentate ligand. Examples of the polydentate ligand include acetylacetone, 3-methyl-2,4-pentanedione, acetylacetaldehyde, 2,4-hexanedione, 2,4-heptanedione, 5-methyl-2,4-hexanedione, 5,5-dimethyl-2,4-hexanedione, benzoylacetone, benzoylacetophenone, salicylaldehyde, 1,1,1-trifluoroacetylacetone, 1,1,1,5,5,5-hexafluoroacetylacetone, 3-methoxy-2,4-pentanedione, 3-cyano-2,4-pentanedione, 3-nitro-2,4-pentanedione, 3-chloro-2,4-pentanedione, acetoacetic acid, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, salicylic acid, methyl salicylate, malonic acid, dimethyl malonate, and diethyl malonate. When coordinated to the metal center, the multidentate ligand has a structure that has one or more protons removed from it.

[0105] Specific examples of metal complex (1) in which M is aluminum include aluminum diisopropylate mono-sec-butylate, aluminum tri-sec-butylate, aluminum triisopropylate, aluminum triethylate, aluminum tris(acetylacetonate), aluminum bis(ethylacetoacetate) mono(acetylacetonate), aluminum tris(ethylacetoacetate), aluminum octadecenylacetoacetate diisopropylate, aluminum ethylacetoacetate diisopropylate, aluminum ethylacetoacetate di-n-butylate, aluminum propylacetoacetate diisopropylate, aluminum n-butylacetoacetate diisopropylate, aluminum tris(ethylacetoacetate), aluminum mono(acetylacetonate)bis(ethylacetoacetate), and aluminum tris(acetylacetonate).

[0106] Specific examples of the metal complex (1) in which M is titanium include tetraisopropyl titanate, tetranormalbutyl titanate, tetraoctyl titanate, tetratert-butyl titanate, tetrastearyl titanate, titanium tetraacetylacetonate, titanium octylene glycolate (also known as bis(2-ethylhexyloxy)bis(2-ethyl-3-oxohexyloxy)titanium(IV)), titanium diisopropoxide bis(ethylacetoacetate), allylacetoacetate triisopropoxide, titanium dinormalbutoxide bis(2,4-pentanedionate), titanium diisopropoxide bis(tet Titanium(IV) tetraisopropoxide bis(methylheptanedionate), titanium diisopropoxide bis(ethylacetoacetate), titanium(IV) tetra(methylphenolate), titanium oxide bis(2,4-pentanedionate), monoisopropoxytitanium triisostearate, diisopropoxytitanium diisostearate.

[0107] Specific examples of the metal complex (1) in which M is zirconium include zirconium tetra-normal propoxide, zirconium tetra-normal butoxide, zirconium tetra(acetylacetonate), zirconium allylacetoacetate triisopropoxide, zirconium di-normal butoxide bis(2,4-pentanedionate), zirconium diisopropoxide bis(2,4-pentanedionate), zirconium diisopropoxide bis(tetramethylheptanedionate), zirconium diisopropoxide bis(ethylacetoacetate), zirconium butoxide(acetylacetate)bis(ethylacetoacetate), zirconium tributoxide monoacetylacetonate, zirconium octylate, zirconium stearate, tri-normal butoxyzirconium monooctylate, and tri-normal butoxyzirconium monostearate.

[0108] When a metal complex is used, its content in the adhesive composition is preferably 0.03 to 3 mass %, more preferably 0.05 to 2.5 mass %, and even more preferably 0.1 to 2 mass %, based on the non-volatile content of the adhesive composition excluding component (D), from the viewpoint of dispersing component (D).

[0109] (curing accelerator) In the present invention, a curing accelerator may be used to accelerate the crosslinking reaction between the epoxy groups in component (A) and the acid anhydride groups and / or carboxyl groups in components (B) and (C). Examples of curing accelerators include imidazole compounds, tertiary and quaternary amine compounds, dimethylurea compounds, and organic phosphine compounds.

[0110] Examples of the imidazole compound include 1H-imidazole, 2-methylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 2-phenyl-4,5-bis(hydroxymethyl)imidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenylimidazole, 2-dodecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. Specific examples of imidazole compounds include Curezol 2MZ, 2P4MZ, 2E4MZ, 2E4MZ-CN, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2PHZ, 1B2MZ, 1B2PZ, 2PZ, C17Z, 1.2DMZ, 2P4MHZ-PW, 2MZ-A, and 2MA-OK (all manufactured by Shikoku Chemicals Corporation).

[0111] The tertiary and quaternary amine compounds are not particularly limited, and examples thereof include quaternary ammonium salts such as tetramethylammonium bromide, tetrabutylammonium bromide, and triethylmethylammonium 2-ethylhexanoate; diazabicyclo compounds such as DBU (1,8-diazabicyclo[5.4.0]undecene-7), DBN (1,5-diazabicyclo[4.3.0]nonene-5), DBU-phenolate, DBU-octylate, DBU-p-toluenesulfonate, DBU-formate, and DBU-phenol novolac resin salt; tertiary amines or salts thereof such as benzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol (TAP); and dimethylurea compounds such as aromatic dimethylurea and aliphatic dimethylurea.

[0112] Examples of dimethylurea compounds include aromatic dimethylureas such as DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) and U-CAT3512T (manufactured by San-Apro Co., Ltd.); and aliphatic dimethylureas such as U-CAT3503N (manufactured by San-Apro Co., Ltd.). Among these, aromatic dimethylureas are preferably used from the viewpoint of curability.

[0113] Examples of organic phosphine compounds include triphenylphosphine, tetraphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, tri-tert-butylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, triphenylphosphine triphenylborane, etc. Specific examples of organic phosphine compounds include TPP, TPP-MK, TPP-K, TTBuP-K, TPP-SCN, TPP-S (all manufactured by Hokko Chemical Industry Co., Ltd.), etc.

[0114] When a curing accelerator is used, its content in the adhesive composition is preferably 0.005 to 1 mass %, more preferably 0.010 to 0.5 mass %, and even more preferably 0.015 to 0.25 mass %, based on the nonvolatile content of the adhesive composition excluding component (D), in order to promote the crosslinking reaction between the epoxy groups of component (A) and the acid anhydride groups and / or carboxyl groups of components (B) and (C).

[0115] adhesive sheet The present invention also provides a pressure-sensitive adhesive sheet having a laminated structure including a support and an adhesive layer formed from the pressure-sensitive adhesive composition of the present invention. A protective sheet may be used in the present invention. That is, the pressure-sensitive adhesive sheet of the present invention may have a laminated structure including a support, an adhesive layer, and a protective sheet in this order. Other layers (e.g., release layers) may be present between the support and the adhesive layer, and between the adhesive layer and the protective sheet.

[0116] Examples of the support and protective sheet include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; cycloolefin polymers; polyesters such as polyethylene terephthalate (hereinafter sometimes referred to as "PET") and polyethylene naphthalate; polycarbonate; and plastic films such as polyimide. The support and protective sheet may both be single-layer films or laminate films.

[0117] The support and protective sheet may be, for example, a low-moisture-permeable film having a barrier layer, or a laminate film of a low-moisture-permeable film having a barrier layer and another film. Examples of barrier layers include inorganic films such as silica vapor deposition films, silicon nitride films, and silicon oxide films. The barrier layer may be composed of multiple layers of inorganic films (e.g., silica vapor deposition films). The barrier layer may also be composed of organic and inorganic materials, or may be a composite multilayer of organic and inorganic films.

[0118] The surface of the protective sheet that contacts the adhesive layer is preferably release-treated. On the other hand, the support may or may not be release-treated. Examples of release treatments include release treatments using a release agent such as a silicone resin-based release agent, an alkyd resin-based release agent, or a fluororesin-based release agent.

[0119] The thickness of the support and the protective sheet is not particularly limited, but from the viewpoint of ease of handling of the pressure-sensitive adhesive sheet, it is preferably 10 to 150 μm, more preferably 20 to 100 μm. When the support and the protective sheet are laminated films, the thickness is the thickness of the laminated film. On the other hand, the thickness of the pressure-sensitive adhesive layer is determined based on the thickness of the laminated film when laminating the pressure-sensitive adhesive sheet onto a substrate having irregularities. From the viewpoint of adhesiveness and water vapor barrier performance, the thickness is preferably 1 to 200 μm, more preferably 3 to 150 μm, and even more preferably 5 to 100 μm. When the thickness of the adhesive layer is 1 μm or more, the adhesive layer can better conform to irregularities and further improve embeddability. When the thickness of the adhesive layer is 200 μm or less, water vapor penetration from the cross section of the adhesive layer can be better suppressed and water vapor barrier performance can be further improved.

[0120] Production of adhesive composition and adhesive sheet The adhesive composition of the present invention can be produced by mixing the above-mentioned components using known equipment.

[0121] The adhesive sheet of the present invention can be produced, for example, by (i) dissolving or dispersing the above-mentioned components in an organic solvent to prepare a varnish of the adhesive composition, (ii) applying the obtained varnish to a support to form a coating film, and (iii) heating the obtained coating film to remove the organic solvent.

[0122] Examples of organic solvents that can be used to prepare the varnish include ketones such as acetone, methyl ethyl ketone, and cyclohexanone; acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; cellosolves such as cellosolve; carbitols such as butyl carbitol; aromatic hydrocarbons such as toluene and xylene; amides of dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; and the like. Only one organic solvent may be used, or two or more may be used in combination. Commercially available organic solvents may also be used. Examples of commercially available organic solvents include "Swasol" manufactured by Maruzen Petrochemical Co., Ltd. and "Ipsol" manufactured by Idemitsu Kosan Co., Ltd. The varnish can be applied by any known method (e.g., a method using a die coater), and the application method is not particularly limited.

[0123] In order to promote the reaction between the epoxy groups of component (A) and the acid anhydride groups and / or carboxyl groups of components (B) and (C), the organic solvent is preferably removed by heating the coating film. The heating temperature of the coating film is preferably 80 to 200°C, more preferably 100 to 180°C, and the heating time is preferably 2 to 90 minutes, more preferably 5 to 60 minutes. The coating film may be heated under normal pressure or under reduced pressure.

[0124] Uses of the adhesive composition and adhesive sheet The pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet of the present invention can be used for sealing electronic devices (e.g., organic EL devices, solar cells, sensor devices, etc.), conductive substrates, etc. Examples of electronic devices include organic EL devices, solar cells, sensor devices, etc. The electronic device is more preferably an electronic device that is sensitive to moisture, such as an organic EL device or a solar cell.

[0125] Electronic Devices The present invention also provides an electronic device comprising an adhesive layer formed from the adhesive composition of the present invention. The electronic device of the present invention can be produced, for example, by (i) producing an adhesive sheet of the present invention using the adhesive composition of the present invention, and (ii) using the adhesive sheet of the present invention to form an adhesive layer in the electronic device (e.g., by laminating the adhesive sheet of the present invention on a substrate of the electronic device to form an adhesive layer). The electronic device of the present invention can also be produced, for example, by using the adhesive sheet of the present invention for interlayer adhesion of multiple materials (e.g., touch panel sensors, polarizing plates, surface protection sheets, etc.), forming an adhesive layer on an arbitrary material (layer) using the adhesive sheet of the present invention, and then laminating another arbitrary material (layer) on top of the adhesive layer. [Example]

[0126] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples and can be practiced with appropriate modifications within the scope of the above and below aims, all of which are included within the technical scope of the present invention. Furthermore, "parts" and "%" in the amounts of components and copolymerized units mean "parts by mass" and "% by mass," respectively, unless otherwise specified.

[0127] <Ingredients> The components used in the examples and comparative examples are shown below. (1) Component (A) "ER853" (Seiko PMC Corporation, glycidyl methacrylate modified propylene-butene random copolymer, epoxy group concentration: 1.63 mmol / g, number average molecular weight: 113,000, propylene unit / butene unit: 71% / 29%) "ER829" (Seiko PMC Corporation, glycidyl methacrylate modified propylene-butene random copolymer, epoxy group concentration: 0.64 mmol / g, number average molecular weight: 168,000, propylene unit / butene unit: 71% / 29%) "ER866" (Seiko PMC Corporation, glycidyl methacrylate modified butyl rubber, epoxy group concentration: 1.63 mmol / g, number average molecular weight: 113,000, isobutene unit / isoprene unit: 98.9% / 1.1%)

[0128] (2)(B) Component "ER645" (Seiko PMC Corporation, maleic anhydride-butyl methacrylate random copolymer modified propylene-butene random copolymer, butyl methacrylate unit concentration: 0.32 mmol / g, acid anhydride group concentration: 1.18 mmol / g, number average molecular weight: 59,000, propylene unit / butene unit: 71% / 29%) "ER661" (manufactured by Seiko PMC Corporation, maleic anhydride-butyl methacrylate random copolymer modified butyl rubber, butyl methacrylate unit concentration: 0.32 mmol / g, acid anhydride group concentration: 0.46 mmol / g, number average molecular weight: 40,000, isobutene unit / isoprene unit ratio: 98.9% / 1.1%)

[0129] (3)(C) component "HV-300M" (manufactured by Toho Chemical Industry Co., Ltd., maleic anhydride-modified liquid polybutene, acid anhydride group concentration: 0.77 mmol / g, number average molecular weight: 2,100)

[0130] (4)(D) Component "DHT-4C" (Kyowa Chemical Industry Co., Ltd., semi-calcined hydrotalcite, median diameter: 400 nm, BET specific surface area: 15 m 2 / g) Calcium oxide (Yoshizawa Lime Industry Co., Ltd., median diameter: 1.8 μm)

[0131] (5) Liquid olefin polymer "HV-1900" (ENEOS Corporation, liquid polybutene, number average molecular weight: 2,900, viscosity at 25°C: 460 Pa·s)

[0132] (6) Tackifier "T-REZ HA105" (manufactured by ENEOS Corporation, hydrogenated dicyclopentadiene petroleum resin, softening point: 104.5°C)

[0133] (7) Antioxidants "Irganox 1010" (BASF, hindered phenol antioxidant)

[0134] (8) Metal complexes "Plenact AL-M" (Ajinomoto Fine-Techno Co., Ltd., aluminum octadecenyl acetoacetate diisopropylate)

[0135] (9) Hardener accelerator 2,4,6-tris(dimethylaminomethyl)phenol (manufactured by Kayaku Nouryon Co., Ltd., hereinafter abbreviated as "TAP")

[0136] Example 1 Varnishes having the blending ratios shown in the table below were prepared by the following procedure, and adhesive sheets were produced using the resulting varnishes. The amount (parts) of each component used in the table below indicates the amount of non-volatile content of each component in the varnish.

[0137] Specifically, a mixture was obtained by dispersing maleic anhydride-modified liquid polybutene ("HV-300M" manufactured by Toho Chemical Industry Co., Ltd.), liquid polybutene ("HV-1900" manufactured by ENEOS Corporation), a metal complex ("Plenact AL-M" manufactured by Ajinomoto Fine-Techno Co., Inc.), and semi-calcined hydrotalcite ("DHT-4C" manufactured by Kyowa Chemical Industry Co., Ltd.) into a Swazol solution (non-volatile content: 60%) of hydrogenated dicyclopentadiene petroleum resin (tackifier, "T-REZ HA105" manufactured by ENEOS Corporation) using a three-roll mill. The resulting mixture was mixed with glycidyl methacrylate-modified propylene-butene random copolymer ("ER853" manufactured by Seiko PMC), maleic anhydride-butyl methacrylate random copolymer-modified propylene-butene random copolymer ("ER645" manufactured by Seiko PMC), hindered phenol antioxidant ("Irganox 1010" manufactured by BASF), curing accelerator (TAP, manufactured by Nouryon Chemical Industries, Ltd.), and toluene. The resulting mixture was uniformly dispersed in a high-speed rotating mixer to obtain a varnish of the adhesive composition. The resulting varnish was uniformly applied to the release-treated surface of a polyethylene terephthalate (PET) film ("SP3000" manufactured by Toyo Cross Co., Ltd., PET film thickness: 38 μm) treated with a silicone-based release agent using a die coater and heated at 130°C for 30 minutes to obtain an adhesive sheet with a 50 μm-thick adhesive layer.

[0138] <Example 2> A varnish of the adhesive composition and an adhesive sheet having an adhesive layer 50 μm thick were prepared in the same manner as in Example 1, except that a glycidyl methacrylate-modified propylene-butene random copolymer ("ER829" manufactured by Seiko PMC Co., Ltd.) was used as component (A) instead of a glycidyl methacrylate-modified propylene-butene random copolymer ("ER853" manufactured by Seiko PMC Co., Ltd.) and the amounts of components (A) and (B) used were changed.

[0139] Example 3 A varnish of the adhesive composition and an adhesive sheet having a 50 μm thick adhesive layer were prepared in the same manner as in Example 1, except that calcium oxide (Yoshizawa Lime Industry Co., Ltd.) was used instead of semi-calcined hydrotalcite (Kyowa Chemical Industry Co., Ltd.'s "DHT-4C") as component (C).

[0140] Example 4 The varnish and adhesive composition were prepared in the same manner as in Example 1, except that glycidyl methacrylate-modified butyl rubber ("ER866" manufactured by Seiko PMC Co., Ltd.) was used as the component (A) instead of the glycidyl methacrylate-modified propylene-butene random copolymer ("ER853" manufactured by Seiko PMC Co., Ltd.), and maleic anhydride-butyl methacrylate random copolymer-modified butyl rubber ("ER661" manufactured by Seiko PMC Co., Ltd.) was used as the component (B) instead of the maleic anhydride-butyl methacrylate random copolymer-modified propylene-butene random copolymer ("ER645" manufactured by Seiko PMC Co., Ltd.), and the amounts of the components (A) and (B) were changed. An adhesive sheet having an adhesive layer with a thickness of 50 μm was prepared.

[0141] <Comparative Example 1> A varnish of the adhesive composition and an adhesive sheet having an adhesive layer 50 μm thick were prepared in the same manner as in Example 1, except that the (B) component was not used and the amounts of the (A) component and the (C) component were changed.

[0142] <Comparative Example 2> A varnish of the adhesive composition and an adhesive sheet having an adhesive layer with a thickness of 50 μm were prepared in the same manner as in Example 1, except that component (C) was not used and the amount of component (A) used was changed.

[0143] <Comparative Example 3> A varnish of the adhesive composition and an adhesive sheet having an adhesive layer with a thickness of 50 μm were prepared in the same manner as in Example 1, except that the (D) component was not used and the amounts of the (A) component and the (B) component were changed.

[0144] <Method for evaluating water vapor barrier performance> A composite film comprising an aluminum foil and a polyethylene terephthalate film ("PET-Tuki AL1N30" manufactured by Tokai Toyo Aluminum Sales Co., Ltd., aluminum foil thickness 30 μm, PET film thickness 25 μm) was prepared as a support (water vapor permeability of the composite film: 0.001 (g / m 2 / 24hr) or less).

[0145] A test sheet having a laminated structure of "support (composite film) / adhesive layer" was obtained in the same manner as in Examples and Comparative Examples, except that the composite film was used as the support. The adhesive layer was formed on the aluminum foil of the composite film.

[0146] A 50 mm x 50 mm square glass plate made of alkali-free glass was prepared, washed with boiled isopropyl alcohol for 5 minutes, and dried at 150°C for 30 minutes or more.

[0147] Calcium was vapor-deposited onto one side of the dried glass plate using a mask that covered the peripheral area 0 mm to 2 mm from the edge of the glass plate, thereby forming a 200 nm-thick calcium film (purity: 99.8%) in the central part of one side of the glass plate, excluding the peripheral area 0 mm to 2 mm from the edge of the glass plate.

[0148] In a nitrogen atmosphere, the adhesive layer of the test sheet and the calcium film side of the glass plate were bonded together using a thermal laminator (Fujipla's "Lamipacker DAiSY A4 (LPD2325)") to obtain a laminate. This laminate was used as an evaluation sample.

[0149] Generally, calcium becomes transparent when it comes into contact with water and becomes calcium oxide. Furthermore, in the evaluation sample described above, the glass plate and aluminum foil have sufficiently high barrier properties against water vapor penetration, so moisture typically migrates in-plane (perpendicular to the thickness direction) through the edge of the adhesive layer to reach the calcium film. When moisture reaches the calcium film, the calcium film gradually oxidizes and becomes transparent from the edge, and shrinkage of the calcium film is observed. Therefore, moisture penetration into the evaluation sample can be evaluated by measuring the sealing distance (mm) from the edge of the evaluation sample to the calcium film. Therefore, the evaluation sample containing the calcium film can be used as a model for electronic devices.

[0150] First, the initial sealing distance X2 (mm) from the edge of the evaluation sample to the edge of the calcium film was The measurement was carried out using a microscope (Mitutoyo Corporation "Measuring Microscope MF-U").

[0151] Next, the evaluation sample was placed in a thermo-hygrostat chamber set at a temperature of 85°C and a humidity of 85%RH. When the sealing distance X1 (mm) between the end of the evaluation sample placed in the thermo-hygrostat chamber and the end of the calcium film increased by 0.1 mm from the initial sealing distance X2, the evaluation sample was removed from the thermo-hygrostat chamber. The time from when the evaluation sample was placed in the thermo-hygrostat chamber to when the evaluation sample was removed from the thermo-hygrostat chamber was calculated as the decrease start time t (hours). This decrease start time t was calculated from the time T when the evaluation sample was placed in the thermo-hygrostat chamber. P1 From the time T, the sealing distance X1 (mm) between the end of the evaluation sample stored in the temperature and humidity chamber and the end of the calcium film becomes "X2 + 0.1 mm". P2 corresponds to the time until

[0152] The sealing distance X1 and decrease start time t were applied to the Fick's diffusion equation (1) to calculate the constant K as a parameter of the water vapor penetration barrier performance.

[0153]

number

[0154] Using the obtained constant K, the water vapor barrier performance of the adhesive layer was evaluated according to the following criteria. The smaller the value of the constant K, the higher the water vapor barrier performance. Note that "hr" below means "hours." The results are shown in the table below. (Standard for water vapor barrier performance) ○: Constant K is 0.02 cm / hr 0.5 less than ×: Constant K is 0.02 cm / hr 0.5 End

[0155] <Method for evaluating bubble suppression performance> The pressure-sensitive adhesive sheets (adhesive layer thickness: 50 μm) prepared in the Examples and Comparative Examples were cut to a length of 50 mm x width of 50 mm. The cut pressure-sensitive adhesive sheets were then laminated onto the vapor-deposited barrier layer surface of a 50 mm x 50 mm barrier film (manufactured by Sumitomo Chemical Co., Ltd.) using a batch-type vacuum laminator (Nichigo-Morton "V-160"). The lamination conditions were a temperature of 80°C, a decompression time of 30 seconds, followed by a pressure of 0.3 MPa for 30 seconds. The PET film on the pressure-sensitive adhesive sheet was then peeled off, and a polyimide film (Ube Industries, UPILEX-50S) was further laminated onto the exposed adhesive layer under the same conditions as above to produce a laminate. The resulting laminate was then placed in a thermo-hygrostat set at 85°C and 85% RH. After 100 hours, the presence or absence of bubbles within the laminate was visually observed and evaluated according to the following criteria. Since the barrier film and polyimide film used in this evaluation method were transparent, the presence or absence of bubbles within the laminate could be visually observed. The results are shown in the table below. (Standard for bubble suppression performance) 〇: No bubbles ×: Air bubbles are generated

[0156] [Table 1]

[0157] The adhesive layers formed from the adhesive compositions of Examples 1 to 4, which satisfied the requirements of the present invention, were excellent in water vapor barrier performance and bubble suppression performance. On the other hand, the adhesive layers formed from the adhesive composition of Comparative Example 1, which did not contain component (B), and the adhesive composition of Comparative Example 2, which did not contain component (C), were poor in bubble suppression performance. Furthermore, the adhesive layer formed from the adhesive composition of Comparative Example 3, which did not contain component (D), was poor in water vapor barrier performance. [Industrial Applicability]

[0158] The pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet of the present invention can be used in, for example, electronic devices (e.g., organic EL devices). It is useful for sealing semiconductor devices, conductive substrates, etc.

Claims

1. The following components (A) to (D): (A) an olefin polymer having an epoxy group; (B) an olefin polymer having an acid anhydride group and / or a carboxy group and a number average molecular weight of 10,000 or more; (C) an olefin polymer having an acid anhydride group and / or a carboxy group and a number average molecular weight of less than 10,000; and (D) Hygroscopic filler An adhesive composition comprising:

2. 2. The pressure-sensitive adhesive composition according to claim 1, wherein the component (B) is an olefin polymer having an acid anhydride group and a number average molecular weight of 10,000 or more.

3. 3. The pressure-sensitive adhesive composition according to claim 1, wherein the component (C) is an olefin polymer having an acid anhydride group and a number average molecular weight of less than 10,000.

4. The pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the number average molecular weight of component (B) is 20,000 to 500,000.

5. The pressure-sensitive adhesive composition according to any one of claims 1 to 4, wherein the number average molecular weight of component (C) is 500 or more and less than 10,000.

6. The pressure-sensitive adhesive composition according to any one of claims 1 to 5, further comprising a liquid olefin polymer other than the components (A), (B) and (C).

7. The adhesive composition according to any one of claims 1 to 6, further comprising a tackifier.

8. A pressure-sensitive adhesive sheet having a laminated structure comprising a support and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of claims 1 to 7.

9. An electronic device comprising an adhesive layer formed from the adhesive composition according to any one of claims 1 to 7.

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