Adhesive composition, circuit connection material, and connector

Abstract

To provide an adhesive composition and a circuit connection material which can achieve both storage stability and peeling resistance under a high temperature and high humidity condition, and a connection body which prevent peeling on an adhesive surface even under a high temperature and high humidity condition.SOLUTION: An adhesive composition contains (a) a thermoplastic resin, (b) a radical polymerizable compound, and (c) a radical polymerization initiator, where the adhesive composition contains (a-1) a polyurethane resin and (a-2) a phenoxy resin as (a) thermoplastic resins, (b-1) a radical polymerizable compound having such a structure that an isocyanate group is protected with a blocking agent and (b-2) a radical polymerizable compound having a phosphoric acid group as (b) radical polymerizable compounds, and the content of (b-2) the radical polymerizable compound having the phosphoric acid group is 1.6 mass% or less with respect to the total amount of the adhesive composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to adhesive compositions, circuit connection materials, and connectors. [Background technology]

[0002] In semiconductor devices or liquid crystal display devices, various adhesive compositions have conventionally been used as circuit connection materials for the purpose of bonding various components within the device. These adhesive compositions require a variety of properties, including adhesiveness, heat resistance, and reliability under high temperature and high humidity conditions.

[0003] The substrates to be bonded have diverse surfaces formed from various materials, such as printed circuit boards, organic materials like polyimide films, metals like copper and aluminum, and metallic compounds like ITO, SiN, and SiO2. Therefore, adhesive compositions are designed to suit each substrate.

[0004] Thermosetting resin compositions containing thermosetting resins such as epoxy resins that exhibit high adhesion and high reliability are known as adhesive compositions for semiconductor elements or liquid crystal display elements (see, for example, Patent Document 1). Such adhesive compositions generally contain an epoxy resin, a curing agent such as a phenolic resin that reacts with the epoxy resin, and a thermal latent catalyst that promotes the reaction between the epoxy resin and the curing agent. Of these, the thermal latent catalyst is an important factor in determining the curing temperature and curing rate. Therefore, various compounds are used as thermal latent catalysts from the viewpoint of storage stability at room temperature and curing rate when heated. These adhesive compositions generally cure by heating at a temperature of 170 to 250°C for 1 to 3 hours to exhibit the desired adhesion.

[0005] On the other hand, radical-curing adhesives containing (meth)acrylate derivatives and peroxides are attracting attention (see, for example, Patent Document 2). Radical-curing adhesives are advantageous in terms of short curing time because the radicals, which are the reactive species, are highly reactive. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 1-113480 [Patent Document 2] International Publication No. 98 / 44067 pamphlet [Overview of the project] [Problems that the invention aims to solve]

[0007] In recent years, the market has been demanding higher levels of reliability in panel quality for liquid crystal display devices and the like. Radical-curing adhesives used as circuit connection materials are required to have sufficient storage stability and the ability to maintain connection reliability even under harsh high-temperature and high-humidity conditions. Therefore, the inventors investigated how to improve the adhesive strength of radical-curing adhesives in order to improve the connection reliability of connection components, and found the following problems.

[0008] When the inventors conducted a detailed observation of the connectors after high-temperature and high-humidity testing, they found that in connectors connected with adhesives that had undergone storage treatment considering practical storage stability (for example, storage at 40°C for 3 days), delamination sometimes occurred between the circuit members and the cured adhesive. The occurrence of delamination does not always correlate with adhesive strength, and further delamination can lead to connection failure of the connector. Therefore, delamination resistance is an important characteristic for radical-curing adhesives.

[0009] Therefore, the present disclosure aims to provide an adhesive composition and circuit connection material that can achieve both storage stability and peel resistance under high temperature and high humidity conditions, as well as a connector that is less prone to peeling at the adhesive surface even under high temperature and high humidity conditions. [Means for solving the problem]

[0010] The gist of this disclosure is as follows: [1] to [8].

[0011] [1] An adhesive composition comprising (a) a thermoplastic resin, (b) a radical polymerizable compound, and (c) a radical polymerization initiator, wherein (a) the thermoplastic resin contains (a-1) a polyurethane resin and (a-2) a phenoxy resin, and (b) the radical polymerizable compound contains (b-1) a radical polymerizable compound having a structure in which an isocyanate group is protected by a blocking agent and (b-2) a radical polymerizable compound having a phosphate group, and the content of (b-2) the radical polymerizable compound having a phosphate group is 1.6% by mass or less based on the total amount of the adhesive composition.

[0012] [2] The adhesive composition according to [1] above, wherein the mass ratio of (a-1) polyurethane resin to (a-2) phenoxy resin is 8:2 to 2:8.

[0013] [3] (a-1) The adhesive composition according to [1] or [2] above, wherein the polyurethane resin is an ester urethane compound.

[0014] [4] (b-1) The adhesive composition according to any one of [1] to [3] above, wherein the radical polymerizable compound having a structure in which an isocyanate group is protected by a blocking agent is a (meth)acrylate compound having a pyrazole-blocked isocyanate group.

[0015] [5] A circuit connection material comprising the adhesive composition described in any of [1] to [4] above.

[0016] [6] The circuit connection material according to [5], further comprising conductive particles.

[0017] [7] A connecting body comprising: a first circuit member having a first circuit electrode formed on the main surface of a first circuit board; a second circuit member having a second circuit electrode formed on the main surface of a second circuit board and arranged such that the second circuit electrode and the first circuit electrode face each other; and a connecting member provided between the first circuit member and the second circuit member for electrically connecting the first circuit member and the second circuit member, wherein the connecting member contains a cured product of the adhesive composition described in any of [1] to [4] above.

[0018] [8] The connector according to [7], wherein at least one of the first circuit board and the second circuit board is a glass substrate. [Advantages of the Invention]

[0019] According to the present disclosure, it is possible to provide an adhesive composition and a circuit connection material that achieve both storage stability and peel resistance under high temperature and high humidity conditions, and a connector in which peeling hardly occurs on the adhesive surface even under high temperature and high humidity conditions. [Brief Description of the Drawings]

[0020] [Figure 1] It is a schematic cross-sectional view showing an embodiment of a film-like circuit connection material containing the adhesive composition according to the present embodiment. [Figure 2] It is a schematic cross-sectional view showing an embodiment of a connector provided with a connection member containing a cured product of the adhesive composition according to the present embodiment. [Figure 3] It is a process diagram schematically showing an embodiment of manufacturing a connector using the circuit connection material according to the present embodiment in a cross-sectional view. [Mode for Carrying Out the Invention]

[0021] In this specification, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described stepwise in this specification, the upper or lower limit of one step in the numerical range may be replaced with the upper or lower limit of another step in the numerical range. Also, in numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. Furthermore, the upper and lower limits described individually can be combined in any way. In this specification, "(meth)acrylate" means at least one of acrylate and its corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl". Furthermore, "(poly)" means both with and without the prefix "poly". Furthermore, "A or B" means that either A or B is included, or both are included. Furthermore, unless otherwise specified, the materials exemplified below may be used individually or in combination of two or more. The content of each component in a composition refers to the total amount of any multiple substances present in the composition, unless otherwise specified, if multiple substances corresponding to each component exist in the composition.

[0022] The embodiments of this disclosure will be described in detail below, with reference to the drawings as appropriate. However, this disclosure is not limited to the embodiments described below.

[0023] <Adhesive composition> The adhesive composition according to this embodiment contains (a) a thermoplastic resin (hereinafter also referred to as "component (a)"), (b) a radical polymerizable compound (hereinafter also referred to as "component (b)"), and (c) a radical polymerization initiator (hereinafter also referred to as "component (c)").

[0024] Examples of the thermoplastic resins in (a) above include one or more resins selected from polyimide resins, polyamide resins, phenoxy resins, poly(meth)acrylic resins, polyester resins, polyurethane resins, polyester urethane resins, and polyvinyl butyral resins.

[0025] The lower limit of the weight-average molecular weight of the thermoplastic resin may be 5,000 or more, 10,000 or more, or 25,000 or more. When the weight-average molecular weight of the thermoplastic resin is 5,000 or more, the adhesive strength of the adhesive composition tends to improve. On the other hand, the upper limit of the weight-average molecular weight of the thermoplastic resin may be 400,000 or less, 200,000 or less, or 150,000 or less. When the weight-average molecular weight of the thermoplastic resin is 400,000 or less, good compatibility with other components tends to be easily obtained, and the fluidity of the adhesive tends to be easily obtained. From the above viewpoint, the weight-average molecular weight of the thermoplastic resin is preferably 5,000 to 400,000, more preferably 5,000 to 200,000, even more preferably 10,000 to 150,000, and particularly preferably 25,000 to 150,000.

[0026] The weight-average molecular weight of a thermoplastic resin is determined by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene, according to the following conditions. [GPC conditions] Equipment used: Hitachi L-6000 model [Hitachi, Ltd.], Column: Gelpack GL-R420 + Gelpack GL-R430 + Gelpack GL-R440 (3 in total) [Hitachi Chemical Co., Ltd.], Eluent: Tetrahydrofuran, Measurement temperature: 40℃, Flow rate: 1.75 ml / min, Detector: L-3300RI [Hitachi, Ltd.]

[0027] As a thermoplastic resin, rubber components can also be used for the purpose of stress relief and improved adhesion.

[0028] The total content of component (a) in the adhesive composition may be 20 to 80 parts by mass, 30 to 70 parts by mass, or 35 to 65 parts by mass per 100 parts by mass of the total amount of components (a) and (b), from the viewpoint of adhesive strength, film-forming properties and fluidity of the adhesive composition.

[0029] The adhesive composition according to this embodiment may contain, as component (a), (a-1) polyurethane resin (hereinafter also referred to as "component (a-1)") and (a-2) phenoxy resin (hereinafter also referred to as "component (a-2)"), from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0030] (a-1) As component, an organic compound having a urethane group and an ester group (hereinafter also referred to as "ester urethane compound") can be used. The ester urethane compound may have a urethane group and an ester group in its main chain.

[0031] Ester urethane compounds are obtained, for example, by the reaction of a polyester polyol with a diisocyanate. The ester urethane compounds obtained by this reaction are sometimes generally referred to as polyester urethane resins.

[0032] As the diisocyanate, aromatic, alicyclic, or aliphatic diisocyanates such as 2,4-tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI), and isophorone diisocyanate (IPDI) are preferably used.

[0033] Polyester polyols can be obtained, for example, by the reaction of a dicarboxylic acid with a diol. Preferred dicarboxylic acids include aromatic and aliphatic dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, and sebatic acid. Preferred diols include glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, hexanediol, neopentyl glycol, diethylene glycol, and triethylene glycol.

[0034] The glass transition temperature of ester urethane compounds is preferably 50°C or higher. The glass transition temperature of ester urethane compounds can be made 50°C or higher by appropriately adjusting the type of polyester polyol or diisocyanate, molecular weight, etc.

[0035] Ester urethane compounds are preferably anionic. This further improves adhesive strength. Anionic ester urethane compounds are obtained by copolymerizing diols or diamines having sulfonic acid groups or carboxyl groups in their side chains during the reaction of polyester polyol and diisocyanate.

[0036] Ester urethane compounds preferably have aromatic groups including benzene rings, etc., or cyclic aliphatic groups including cyclohexane rings, etc.

[0037] Ester urethane compounds can be used in combination of two or more types. For example, a compound obtained by the reaction of an aromatic polyester polyol with an aliphatic diisocyanate can be combined with a compound obtained by the reaction of an aliphatic polyester polyol with an aromatic diisocyanate.

[0038] The ester urethane compound may have a weight-average molecular weight of 5,000 to 100,000 from the viewpoint of film-forming properties when molded into a film, solubility in solvents, and compatibility, and may also have a weight-average molecular weight of 5,000 to 400,000 from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0039] The ester urethane compound may have epoxy groups. When the adhesive composition contains an ester urethane compound having epoxy groups and an epoxy resin, the reaction between the epoxy resin and the ester urethane compound can improve the elastic modulus and heat resistance of the cured product of the circuit connection material.

[0040] (a-1) Component (a) can be used individually or in combination of two or more components.

[0041] (a-2) The phenoxy resin, which is component (a-2), may have a weight-average molecular weight of 10,000 or more, or it may be between 10,000 and 1,000,000.

[0042] The phenoxy resin may have a glass transition temperature of -50°C or higher, or it may be between 0 and 250°C.

[0043] (a-2) Components can be used individually or in combination of two or more.

[0044] The mass ratio of component (a-1) to component (a-2) may be 8:2 to 2:8, 7:3 to 3:7, or 6:4 to 4:6, from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0045] The adhesive composition according to this embodiment may contain components (a-1) and (a-2) in total at an amount of 20-80% by mass, 20-70% by mass, or 20-60% by mass, based on the total amount of the adhesive composition, from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0046] The content of component (a-1) in the adhesive composition according to this embodiment may be 5 to 50 parts by mass, 5 to 40 parts by mass, or 5 to 30 parts by mass per 100 parts by mass of the total amount of components (a) and (b), from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0047] The content of component (a-2) in the adhesive composition according to this embodiment may be 5 to 50 parts by mass, 5 to 40 parts by mass, or 5 to 30 parts by mass per 100 parts by mass of the total amount of components (a) and (b), from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0048] The adhesive composition according to this embodiment may contain, from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions, (b) as a radical polymerizable compound, (b-1) a radical polymerizable compound having a structure in which an isocyanate group is protected by a blocking agent (hereinafter also referred to as "component (b-1)") and (b-2) a radical polymerizable compound having a phosphate group (hereinafter also referred to as "component (b-2)").

[0049] Component (b-1) may have a radically polymerizable unsaturated group. Examples of radically polymerizable unsaturated groups include (meth)acryloyl groups and (meth)acryloyloxy groups.

[0050] Component (b-1) can be synthesized by chemically blocking the isocyanate group of a compound having an isocyanate group and a (meth)acryloyloxy group with a blocking agent.

[0051] Methods for producing compounds having an isocyanate group and a (meth)acryloyloxy group include, as described in Japanese Patent Publication No. 2006-232797, a method of reacting (meth)acrylic acid with an ester salt of an amino alcohol and phosgene, a method of reacting isopropenyloxazoline with phosgene, and a method of dehydrochlorinating a 3-chloropropionic acid ester derivative having an isocyanate group.

[0052] The molecular weight of a compound having an isocyanate group and a (meth)acryloyloxy group may be 150 or more and less than 1000.

[0053] In compounds having an isocyanate group and a (meth)acryloyloxy group, there are no particular restrictions on the number of isocyanate groups and (meth)acryloyloxy groups in the molecule, but it is practical to have approximately 1 to 5 of each independently.

[0054] Examples of compounds having an isocyanate group and a (meth)acryloyloxy group include 2-(meth)acryloyloxyethyl isocyanate, 2-(meth)acryloyloxymethyl isocyanate, 2-(meth)acryloyloxypropyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate.

[0055] Examples of blocking agents include dimethylpyrazole, dimethyl malonate, diethyl malonate, methyl ethyl ketone oxime, and caprolactam. Since the temperature at which the blocking agent dissociates can be controlled depending on the type of blocking agent, these blocking agents can be used individually or in combination of two or more, depending on the practical temperature.

[0056] (b-1) Component may be, for example, a compound obtained by blocking a compound having the above-mentioned isocyanate group and (meth)acryloyloxy group with the above-mentioned blocking agent. Specific examples include 2-(0-[1'-methylpropyleneneamino]carboxyamino)ethyl (meth)acrylate and 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate.

[0057] (b-1) Component (b-1) may be a (meth)acrylate compound having a pyrazole-blocked isocyanate group, such as 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate, from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0058] (b-1) Component (b) can be used individually or in combination of two or more components.

[0059] (b-1) The content of component (a) may be 1 to 25 parts by mass, 1 to 20 parts by mass, or 1 to 15 parts by mass, based on 100 parts by mass of the total amount of component (a) and component (b), from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0060] Moreover, from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high-temperature and high-humidity conditions, the content of the component (b-1) may be 1 to 50 parts by mass, may be 1 to 40 parts by mass, or may be 1 to 30 parts by mass based on 100 parts by mass of the total amount of the component (b).

[0061] Examples of the component (b-2) include compounds represented by the following formulas (1), (2), or (3).

[0062]

Chemical formula

[0063]

Chemical formula

[0064]

Chemical formula

[0065] Examples of radical polymerizable compounds having a phosphate group include acid phosphooxyethyl (meth)acrylate, acid phosphooxypropyl (meth)acrylate, acid phosphooxypolyoxyethylene glycol mono(meth)acrylate, acid phosphooxypolyoxypropylene glycol mono(meth)acrylate, 2,2'-di(meth)acryloyloxydiethyl phosphate, EO (ethylene oxide) modified phosphate di(meth)acrylate, phosphate modified epoxy (meth)acrylate, and vinyl phosphate.

[0066] (b-2) Components can be used individually or in combination of two or more.

[0067] (b-2) The content of component (b-2) may be 1.6% by mass or less, 0.4 to 1.6% by mass, 0.5 to 1.6% by mass, or 1.0 to 1.6% by mass, based on the total amount of the adhesive composition (excluding conductive particles), from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0068] Furthermore, the content of component (b-2) may be 0.5 to 1.9 parts by mass or 1.2 to 1.9 parts by mass, based on 100 parts by mass of the total amount of components (a) and (b), from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0069] Furthermore, the content of component (b-2) may be 0.8 to 3.4 parts by mass or 2.1 to 3.4 parts by mass, based on 100 parts by mass of the total amount of component (b), from the viewpoint of achieving both storage stability and peel resistance and adhesive strength under high temperature and high humidity conditions.

[0070] In addition to the components (b-1) and (b-2) described above, the adhesive composition according to this embodiment may also contain any other compound having a radically polymerizable functional group as the (b) radical polymerizable compound. The other compound may be, for example, either a monomer or oligomer of the compound described later, or a combination of both.

[0071] As other compounds mentioned above, polyfunctional (meth)acrylate compounds having two or more (meth)acryloyloxy groups, one or more of them, are preferred. Examples of such (meth)acrylate compounds include epoxy (meth)acrylate, urethane (meth)acrylate, polyether (meth)acrylate, polyester (meth)acrylate, trimethylolpropane tri(meth)acrylate, polyalkylene glycol di(meth)acrylate such as polyethylene glycol di(meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, neopentyl glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, isocyanuric acid-modified bifunctional (meth)acrylate, and isocyanuric acid-modified trifunctional (meth)acrylate. Examples of the epoxy (meth)acrylates mentioned above include epoxy (meth)acrylates obtained by adding (meth)acrylic acid to two glycidyl groups of bisphenol full orange glycidyl ether, and compounds obtained by introducing a (meth)acryloyloxy group to a compound obtained by adding ethylene glycol and / or propylene glycol to two glycidyl groups of bisphenol full orange glycidyl ether. These compounds can be used individually or in combination of two or more.

[0072] Furthermore, the adhesive composition may also contain (b) a monofunctional (meth)acrylate compound as a radical polymerizable compound for the purpose of adjusting fluidity, etc. Examples of monofunctional (meth)acrylate compounds include pentaerythritol (meth)acrylate, 2-cyanoethyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-hexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, isobornyl (meth)acrylate, isodecyl ( Examples include meth)acrylate, isooctyl(meth)acrylate, n-lauryl(meth)acrylate, 2-methoxyethyl(meth)acrylate, 2-phenoxyethyl(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, 2-(meth)acryloyloxyethyl phosphate, N,N-dimethylaminoethyl(meth)acrylate, N,N-dimethylaminopropyl(meth)acrylate, glycidyl group-containing (meth)acrylate obtained by reacting one of the glycidyl groups of an epoxy resin having multiple glycidyl groups with (meth)acrylic acid, and (meth)acryloylmorpholine. These compounds can be used individually or in combination of two or more.

[0073] Furthermore, the adhesive composition may also contain, for the purpose of improving the crosslinking ratio, (b) a radical polymerizable compound, which is a compound having a radical polymerizable functional group such as an allyl group, a maleimide group, or a vinyl group.

[0074] Furthermore, the adhesive composition may also contain, from the viewpoint of balancing crosslinking density and curing shrinkage, further reducing connection resistance, and improving connection reliability, (b) a radical polymerizable compound, which is a compound in which polymerizable groups such as vinyl groups, allyl groups, and (meth)acryloyl groups are introduced to the terminals or side chains of thermoplastic resins such as acrylic resins, phenoxy resins, and polyurethane resins. In this case, the weight-average molecular weight of the above compound may be 3,000 or more, 5,000 or more, or 10,000 or more, from the viewpoint of excellent balance between crosslinking density and curing shrinkage. Also, from the viewpoint of excellent compatibility with other components, the weight-average molecular weight of the above compound may be 1,000,000 or less, 500,000 or less, or 250,000 or less. Note that the weight-average molecular weight of the above compound refers to the value measured using a calibration curve with standard polystyrene by gel permeation chromatography (GPC) according to the conditions described in the examples.

[0075] The above compound may also be an ester urethane compound having a radically polymerizable unsaturated double bond, or a radically polymerizable unsaturated double bond and an epoxy resin. In this case, the elastic modulus and heat resistance of the cured product of the circuit connection material can be improved.

[0076] As for the other compounds mentioned above, (poly)urethane (meth)acrylate compounds can be used when used in combination with components (b-1) and (b-2) to balance crosslinking density and curing shrinkage, further reduce connection resistance, and improve peel resistance and adhesive strength under high temperature and high humidity conditions. The (poly)urethane (meth)acrylate compound may also be an ester urethane compound having a (meth)acryloyl group. In this case, the elastic modulus and heat resistance of the cured product of the circuit connection material can be improved.

[0077] The content of the (poly)urethane (meth)acrylate compound may be 30 to 90% by mass, or 30 to 80% by mass, based on the total mass of component (b).

[0078] Furthermore, the content of the (poly)urethane (meth)acrylate compound may be 50 to 90 parts by mass, or 50 to 80 parts by mass, per 100 parts by mass of the total amount of component (b-1) and component (b-2).

[0079] The total content of component (b) in the adhesive composition may be 20 to 80 parts by mass, 30 to 70 parts by mass, or 35 to 65 parts by mass, based on 100 parts by mass of the total amount of components (a) and (b).

[0080] (c) The radical polymerization initiator can be arbitrarily selected from compounds such as peroxides and azo compounds. From the viewpoint of stability, reactivity and compatibility, peroxides with a 1-minute half-life temperature of 90 to 175°C and a molecular weight of 180 to 1000 are preferred. "1-minute half-life temperature" refers to the temperature at which the half-life of the peroxide is 1 minute. "Half-life" refers to the time it takes for the concentration of a compound to decrease to half of its initial value at a given temperature.

[0081] Examples of radical polymerization initiators include 1,1,3,3-tetramethylbutyl peroxyneodecanoate, di(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, t-hexyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyneoheptanoate, t-amyl peroxy-2-ethylhexanoate, di-t-butyl peroxyhexahydroterephthalate, t-amyl peroxy-3,5,5-trimethylhexanoate, 3-Hydroxy-1,1-dimethylbutyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-amyl peroxyneodecanoate, t-amyl peroxy-2-ethylhexanoate, 3-methylbenzoyl peroxide, 4-methylbenzoyl peroxide, di(3-methylbenzoyl) peroxide, dibenzoyl peroxide, di(4-methylbenzoyl) peroxide, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azo Bis(1-acetoxy-1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), dimethyl-2,2'-azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 1,1'-azobis(1-cyclohexanecarbonitride), t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,It is one or more compounds selected from 5-di(3-methylbenzoylperoxy)hexane, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxybenzoate, dibutylperoxytrimethyladipate, t-amylperoxyn-octoate, t-amylperoxyisononanoate, and t-amylperoxybenzoate.

[0082] The content of the radical polymerization initiator is preferably 1 to 15 parts by mass, more preferably 2.5 to 10 parts by mass, and even more preferably 3 to 8 parts by mass, based on 100 parts by mass of the total amount of component (a) and component (b).

[0083] The adhesive composition according to this embodiment may contain a silane coupling agent. As the silane coupling agent, a compound represented by the following formula (4) can be used.

[0084] [ka] In formula (4), R 1 , R 2 and R 3 Each of these independently represents a hydrogen atom, a C1-C5 alkyl group, a C1-C5 alkoxy group, a C1-C5 alkoxycarbonyl group, or an aryl group. 1 , R 2 and R 3 At least one of them is an alkoxy group. 4 is an integer between 0 and 10.

[0085] Examples of silane coupling agents of formula (4) include vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatetopropyltriethoxysilane. These compounds can be used individually or in combination of two or more.

[0086] The amount of silane coupling agent may be 0.1 to 10 parts by mass or 0.25 to 5 parts by mass per 100 parts by mass of the total amount of component (a) and component (b).

[0087] The adhesive composition according to this embodiment may contain a filler. Examples of fillers include insulating organic or inorganic fine particles. Examples of inorganic fine particles include metal oxide fine particles such as silica fine particles, alumina fine particles, silica-alumina fine particles, titania fine particles, and zirconia fine particles, as well as nitride fine particles. Examples of organic fine particles include silicone fine particles, methacrylate-butadiene-styrene fine particles, acrylic-silicone fine particles, polyamide fine particles, and polyimide fine particles. These fine particles may have a uniform structure or a core-shell structure.

[0088] The amount of filler may be 5 to 30 parts by mass or 7.5 to 20 parts by mass per 100 parts by mass of the total amount of component (a) and component (b), from the viewpoint of maintaining electrical connection between opposing electrodes and improving the fluidity of the adhesive composition.

[0089] Furthermore, the adhesive composition of this embodiment may contain other additives such as softeners, accelerators, degradation inhibitors, colorants, flame retardants, thixotropic agents, and polymerization inhibitors. Examples of polymerization inhibitors include hydroquinones, methyl ether hydroquinones, TEMPO (e.g., 4-benzoyloxy-2,2,6,6-tetramethylpiperidinooxyl free radical, 2,2,6,6-tetramethylpiperidinooxyl free radical), and hindered amines.

[0090] The adhesive composition according to this embodiment can be used as a paste adhesive if it is liquid at room temperature (25°C). If the adhesive composition is solid at room temperature, it may be heated before use or paste-formed by adding a solvent. The solvent used for paste formation is not particularly limited as long as it has substantially no reactivity with the adhesive composition (including additives) and is capable of sufficiently dissolving the adhesive composition.

[0091] The adhesive composition according to this embodiment can also be formed into a film and used as a film-type adhesive. A film-type adhesive can be obtained, for example, by adding a solvent or the like to the adhesive composition as needed, applying the resulting solution to a release support such as a fluororesin film, polyethylene terephthalate film, or release paper, and then removing the solvent or the like. Film-type adhesives are even more convenient in terms of handling and other aspects.

[0092] <Circuit connection materials> The circuit connection material according to this embodiment includes the adhesive composition according to this embodiment described above.

[0093] The circuit connection material according to this embodiment may further contain conductive particles. The circuit connection material containing conductive particles can be particularly suitable as an anisotropic conductive adhesive.

[0094] Examples of conductive particles include metal particles such as Au, Ag, Pd, Ni, Cu, and solder, as well as carbon particles. Furthermore, conductive particles may be composite particles having a core particle made of a non-conductive material such as glass, ceramic, or plastic, and a conductive layer made of metal, metal particles, or carbon coating the core particle. The metal particles may also be particles having copper particles and a silver layer coating the copper particles. The core particle of the composite particle is preferably a plastic particle.

[0095] The composite particles, with the above-mentioned plastic particles as core particles, are deformable by heating and pressurizing, thus increasing the contact area between the circuit electrodes of the circuit members and the conductive particles when bonding the circuit members together. Therefore, a circuit connection material containing these composite particles as conductive particles provides a connection body with even greater reliability.

[0096] The circuit connection material may contain insulating coated conductive particles having the above-mentioned conductive particles and an insulating layer or insulating particles covering at least a portion of their surface. The insulating layer can be provided by methods such as hybridization. The insulating layer or insulating particles are formed from an insulating material such as a polymer resin. By using such insulating coated conductive particles, short circuits between adjacent conductive particles become less likely to occur.

[0097] The average particle size of the conductive particles is preferably 1 to 18 μm, from the viewpoint of obtaining good dispersibility and conductivity.

[0098] The content of conductive particles may be 0.1 to 30 volume%, 0.1 to 10 volume%, or 0.5 to 7.5 volume%, based on the total volume of the circuit connection material, from the viewpoint of ensuring conductivity and minimizing short circuits between circuit electrodes. The content of conductive particles (volume%) is determined based on the volume of each component and conductive particles at 23°C before curing of the adhesive composition. The volume of each component and conductive particles can be determined by converting mass to volume using specific gravity. Alternatively, without dissolving or swelling the component whose volume is to be measured, a suitable solvent (water, alcohol, etc.) that can thoroughly wet the component can be placed in a graduated cylinder, and the increased volume of the component to be measured can be determined as the volume of that component.

[0099] If the circuit connection material is liquid at room temperature (25°C), it can be used as a paste-type circuit connection material. If the adhesive composition is solid at room temperature, it may be heated before use, or it may be paste-formed by adding a solvent. The solvent used for paste formation is not particularly limited, as long as it has substantially no reactivity with the adhesive composition (including additives) and is capable of sufficiently dissolving the adhesive composition.

[0100] The circuit connection material according to this embodiment can also be formed into a film and used as a film-type circuit connection material. The film-type circuit connection material can be obtained, for example, by applying a coating solution obtained by adding a solvent or the like as needed to a mixture of an adhesive composition and conductive particles onto a release support such as a fluororesin film, polyethylene terephthalate film, or release paper, and then removing the solvent or the like.

[0101] Figure 1 is a schematic cross-sectional view showing one embodiment of a film-like circuit connection material containing the adhesive composition according to this embodiment. The laminated film 100 shown in Figure 1 comprises a support 8 and a film-like circuit connection material 40 that is peelably laminated on the support 8. The circuit connection material 40 is composed of an insulating adhesive layer 5 and conductive particles 7 dispersed in the insulating adhesive layer 5. The insulating adhesive layer 5 is composed of the adhesive composition described above. This circuit connection material is easy to handle, can be easily installed on an adherend, and connection work can be easily performed. The circuit connection material may have a multilayer structure consisting of two or more layers. When the film-like circuit connection material contains conductive particles, the film-like circuit connection material can be suitably used as an anisotropic conductive film.

[0102] According to the adhesive composition or circuit connection material of this embodiment, adherends can usually be bonded together by a combination of heating and pressurizing. The heating temperature is preferably 100 to 250°C. The pressure is not particularly limited as long as it does not damage the adherends, but is generally preferably 0.1 to 10 MPa. These heating and pressurizing steps are preferably performed for a period of 0.5 to 120 seconds. According to the adhesive composition or circuit connection material of this embodiment, adherends can be sufficiently bonded together even with short heating and pressurizing periods of 5 seconds at conditions of approximately 140°C and 3 MPa.

[0103] The adhesive composition or circuit connection material according to this embodiment can be used as an adhesive for different types of adherends with different coefficients of thermal expansion. Specifically, the adhesive composition or circuit connection material according to this embodiment can be used not only as an anisotropic conductive adhesive, but also as a circuit connection material such as silver paste or silver film, a semiconductor device adhesive material such as a CSP elastomer, a CSP underfill material, or LOC tape.

[0104] The following describes an example of manufacturing a connector by using the circuit connection material according to this embodiment as an anisotropic conductive film to connect circuit boards and circuit members having circuit electrodes formed on the main surface of the circuit boards as adherends.

[0105] Figure 2 is a schematic cross-sectional view showing one embodiment of a connecting body comprising a connecting member made of a cured product of the adhesive composition according to this embodiment. The connecting body 1 shown in Figure 2 comprises a first circuit member 20 and a second circuit member 30 arranged opposite each other. A connecting member 10 is provided between the first circuit member 20 and the second circuit member 30 for bonding and connecting them.

[0106] The first circuit member 20 comprises a first circuit board 21 and a first circuit electrode 22 formed on the main surface 21a of the first circuit board 21. An insulating layer may be formed on the main surface 21a of the first circuit board 21.

[0107] The second circuit member 30 comprises a second circuit board 31 and a second circuit electrode 32 formed on the main surface 31a of the second circuit board 31. An insulating layer may also be formed on the main surface 31a of the second circuit board 31.

[0108] The first circuit member 20 and the second circuit member 30 are not particularly limited as long as they have circuit electrodes that require electrical connection. Examples of the first circuit board 21 and the second circuit board 31 include inorganic material substrates such as semiconductors, glass, and ceramics, organic material substrates such as polyimide and polycarbonate, and substrates containing both inorganic and organic materials such as glass / epoxy. The first circuit board 21 may be a glass substrate and the second circuit board 31 may be a flexible substrate (preferably a resin film such as a polyimide film).

[0109] Specific examples of the circuit components to be connected include glass or plastic substrates with electrodes such as ITO (indium tin oxide) films formed on them, printed circuit boards, ceramic circuit boards, flexible circuit boards, and semiconductor silicon chips used in liquid crystal displays. These are used in combination as needed. Thus, according to the circuit connection material of this embodiment, in addition to components having surfaces formed from organic materials such as printed circuit boards and polyimide films, metals such as copper and aluminum, ITO, and silicon nitride (SiN) can be used.x It can be used to bond circuit components having a wide variety of surface conditions, such as components having surfaces formed from inorganic materials like silicon dioxide (SiO2).

[0110] For example, when one circuit component is a solar cell having electrodes such as finger electrodes or busbar electrodes, and the other circuit component is a tab wire, the connection obtained by connecting them is a solar cell module comprising a solar cell, a tab wire, and a connecting component (cured product of an adhesive composition) that adheres them together.

[0111] The connecting member 10 contains a cured product of the adhesive composition according to this embodiment. The connecting member 10 contains an insulating layer 11 and conductive particles 7 dispersed in the insulating layer 11. The conductive particles 7 are arranged not only between the opposing first circuit electrode 22 and second circuit electrode 32, but also between the main surfaces 21a and 31a. Since the first circuit electrode 22 and the second circuit electrode 32 are electrically connected via the conductive particles 7, the connection resistance between the first circuit electrode 22 and the second circuit electrode 32 is sufficiently reduced. Therefore, the flow of current between the first circuit electrode 22 and the second circuit electrode 32 can be made smooth, and the circuit can fully perform its function. If the connecting member does not contain conductive particles, the first circuit electrode 22 and the second circuit electrode 32 are electrically connected by contact.

[0112] Since the connecting member 10 is formed from the cured product of the adhesive composition according to this embodiment, the adhesive strength of the connecting member 10 to the first circuit member 20 and the second circuit member 30 is sufficiently high, and the connecting member 10 also has excellent peel resistance. Furthermore, even after reliability tests (high temperature and high humidity tests), peeling is unlikely to occur, and the decrease in adhesive strength and increase in connection resistance can be sufficiently suppressed.

[0113] The connector 1 can be manufactured, for example, by a method comprising the steps of: arranging a pair of circuit members having circuit electrodes and positioned opposite each other with a film-like circuit connection material in between; and bonding the pair of circuit members and the circuit connection material together via a cured adhesive composition by heating and curing them while applying pressure in the thickness direction of the circuit connection material (this connection step).

[0114] Figure 3 is a schematic cross-sectional view showing one embodiment of manufacturing a connector using the circuit connection material according to this embodiment. As shown in Figure 3(a), the film-like circuit connection material 40 is placed on the main surface of the first circuit member 20 on the side of the first circuit electrode 22. When the film-like circuit connection material 40 is provided on the support described above, the laminate of the film-like circuit connection material and the support is placed on the circuit member in an orientation where the film-like circuit connection material 40 is positioned on the side of the first circuit member 20. The film-like circuit connection material 40 is easy to handle because it is in film form. Therefore, the film-like circuit connection material 40 can be easily interposed between the first circuit member 20 and the second circuit member 30, and the connection work between the first circuit member 20 and the second circuit member 30 can be easily performed.

[0115] The film-like circuit connection material 40 is the aforementioned circuit connection material formed in a film shape, and has conductive particles 7 and an insulating adhesive layer 5. Even if the circuit connection material does not contain conductive particles, it can be used as a circuit connection material for electrical connection by directly connecting circuit electrodes. Circuit connection materials that do not contain conductive particles are sometimes called NCF (Non-Conductive-FILM) or NCP (Non-Conductive-Paste). When the circuit connection material contains conductive particles, the circuit connection material using these particles is sometimes called ACF (Anisotropic Conductive FILM) or ACP (Anisotropic Conductive Paste).

[0116] The thickness of the film-like circuit connection material 40 is preferably 10 to 50 μm. If the thickness of the film-like circuit connection material 40 is 10 μm or more, the space between the first circuit electrode 22 and the second circuit electrode 32 tends to be easily filled with adhesive. If the thickness of the film-like circuit connection material is 50 μm or less, the adhesive composition between the first circuit electrode 22 and the second circuit electrode 32 can be sufficiently removed, and electrical conductivity between the first circuit electrode 22 and the second circuit electrode 32 can be easily ensured.

[0117] By applying pressures A and B in the thickness direction of the film-like circuit connection material 40, as shown in Figure 3(a), the film-like circuit connection material 40 is temporarily connected to the first circuit member 20 (see Figure 3(b)). At this time, heating may be performed while applying pressure. However, the heating temperature is set to a temperature that is sufficiently lower than the temperature at which the adhesive composition in the film-like circuit connection material 40 does not harden, i.e., the temperature at which the radical polymerization initiator rapidly generates radicals.

[0118] Next, as shown in Figure 3(c), the second circuit member 30 is placed on the film-like circuit connection material 40 with the second circuit electrode facing the first circuit member 20. If the film-like circuit connection material 40 is provided on a support, the support is peeled off before placing the second circuit member 30 on the film-like circuit connection material 40.

[0119] Subsequently, the film-like circuit connection material 40 is heated while applying pressures A and B in its thickness direction. The heating temperature at this time is set to a temperature at which the radical polymerization initiator generates sufficient radicals. As a result, radicals are generated from the radical polymerization initiator, and polymerization of the radical polymerizable compound begins. This connection yields the connector shown in Figure 2. By heating the film-like circuit connection material 40, the insulating adhesive hardens with the distance between the first circuit electrode 22 and the second circuit electrode 32 sufficiently reduced, forming an insulating layer 11. As a result, the first circuit member 20 and the second circuit member 30 are firmly connected via the connection member 10 including the insulating layer 11.

[0120] This connection is preferably performed under conditions of a heating temperature of 100 to 250°C, a pressure of 0.1 to 10 MPa, and a pressurizing time of 0.5 to 120 seconds. These conditions are appropriately selected depending on the application, adhesive composition, and circuit components. According to the circuit connection material of this embodiment, a connection with sufficient reliability can be obtained even under low temperature conditions of 140°C or less. After this connection, post-curing may be performed as needed. [Examples]

[0121] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to these examples.

[0122] <Synthesis of ester urethane compound EU1> In a stainless steel autoclave equipped with a heater, a stirrer, thermometer, condenser, vacuum generator, and nitrogen gas inlet tube, 48 parts by mass of isophthalic acid and 37 parts by mass of neopentyl glycol were added, followed by 0.02 parts by mass of tetrabutoxytitanate as a catalyst. The mixture was then heated to 220°C under a nitrogen stream and stirred for 8 hours. After that, the pressure was reduced to atmospheric pressure (760 mmHg) and cooled to room temperature. This caused a white precipitate to form. The white precipitate was then removed, washed with water, and vacuum-dried to obtain a polyester polyol. After thoroughly drying the obtained polyester polyol, it was dissolved in MEK (methyl ethyl ketone) and placed in a four-necked flask equipped with a stirrer, dropping funnel, reflux condenser, and nitrogen gas inlet tube. Furthermore, dibutyltin laurate was added as a catalyst in an amount of 0.05 parts by mass per 100 parts by mass of polyester polyol, and 4,4'-diphenylmethane diisocyanate in an amount of 50 parts by mass per 100 parts by mass of polyester polyol was dissolved in MEK and added using a dropping funnel. The mixture was then stirred at 80°C for 4 hours to obtain the target ester urethane compound EU1.

[0123] <Synthesis of urethane acrylate compound UA1> A reaction solution was prepared by charging a 2-liter four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser with 4000 parts by mass of polycarbonate diol (Aldrich, number average molecular weight Mn=2000), 238 parts by mass of 2-hydroxyethyl acrylate, 0.49 parts by mass of hydroquinone monomethyl ether, and 4.9 parts by mass of tin catalyst. To the reaction solution heated to 70°C, 666 parts by mass of isophorone diisocyanate (IPDI) was uniformly added dropwise over 3 hours and the reaction was allowed to proceed. After the addition was complete, the reaction was continued for 15 hours, and the reaction was terminated when the NCO content was confirmed to be 0.2% by mass using a potentiometric automatic titrator (product name AT-510, Kyoto Electronics Manufacturing Co., Ltd.), yielding urethane acrylate compound UA1. Analysis by GPC revealed that the weight-average molecular weight of urethane acrylate compound UA1 was 8500 (standard polystyrene equivalent). The GPC analysis was performed under the conditions shown in Table 1 below.

[0124] [Table 1]

[0125] <Preparation of conductive particles> A nickel layer with a thickness of 0.2 μm was formed on the surface of polystyrene particles, and then a gold layer with a thickness of 0.04 μm was formed on the outside of this nickel layer. In this way, conductive particles with an average particle size of 4 μm were produced.

[0126] <Fabrication of circuit connection materials> An adhesive composition was obtained by mixing the raw materials shown in Table 2 in the mass ratio shown in Table 2. The conductive particles were dispersed in this composition at a rate of 1.5 volume% to obtain a coating solution for forming a film-like circuit connection material. This coating solution was applied to a polyethylene terephthalate (PET) film with a thickness of 50 μm using a coating apparatus. The coating film was dried with hot air at 70°C for 10 minutes to form a film-like circuit connection material with a thickness of 18 μm.

[0127] The values ​​shown in Table 2 represent the parts by mass of solids. The specific substances of each raw material listed in Table 2 are as follows: • Polyurethane resin: EU1, an ester urethane compound synthesized as described above. • Phenoxy resin: A 40% by mass solution prepared by dissolving 40g of PKHC (manufactured by Union Carbide, trade name: average molecular weight 45000) in 60g of methyl ethyl ketone. • Urethane acrylate compound: The urethane acrylate compound UA1 synthesized as described above, • Radical polymerizable compound A: 2-(0-[1'-methylpropyleneamino]carboxyamino)ethyl methacrylate, • Radical polymerizable compound B: 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate, • Radical polymerizable compound C: Monofunctional acrylate compound (trade name Alix CHA, manufactured by Toagosei Co., Ltd.: cyclohexyl acrylate) • Phosphate ester: 2-methacryloyloxyethyl acid phosphate (product name Light Ester P-2M, manufactured by Kyoeisha Chemical Co., Ltd.) • Silane coupling agent: 3-methacryloxypropyltrimethoxysilane (product name KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) • Peroxide: Lauroyl peroxide (product name Perloyl L, manufactured by NOF Corporation: molecular weight 398.6) • Inorganic fine particles: A 10% by mass dispersion prepared by dispersing 10g of silica particles (product name R104, manufactured by Nippon Aerosil Co., Ltd.) in a mixed solvent of 45g of toluene and 45g of ethyl acetate.

[0128] <Fabrication of the connector> Using the above-mentioned film-like circuit connection material, a flexible circuit board (FPC) having 2200 copper circuits with a line width of 75 μm, a pitch of 150 μm, and a thickness of 18 μm was connected to an ITO substrate (thickness 1.1 mm, surface resistance 20 Ω / □) having a glass substrate and a thin layer of indium oxide (ITO) with a thickness of 0.2 μm formed on the glass substrate. The connection was made using a thermocompression bonding device (heating method: constant heat type, manufactured by Toray Engineering Co., Ltd.) by heating and pressurizing at 140°C and 3 MPa for 5 seconds. As a result, a connection body was fabricated in which the FPC and the ITO substrate were connected by the cured product of the circuit connection material over a width of 1.5 mm.

[0129] <Measuring adhesive strength> The adhesive strength of the obtained joints was measured using the 90-degree peel method in accordance with JIS-Z0237. A Tensilon UTM-4 (manufactured by Toyo Baldwin Co., Ltd., product name, peel strength 50 mm / min, 25°C) was used as the adhesive strength measuring device. The adhesive strength was measured on joints after being held in a constant temperature and humidity chamber at 85°C and 85%RH for 250 hours.

[0130] <Evaluation of peel resistance> For the connectors prepared in the same manner as described above and kept in a constant temperature and humidity chamber at 85°C and 85%RH for 250 hours, the interface between the electrode portion of the glass substrate and the cured product of the circuit connection material was observed from the glass substrate side using a microscope (Nikon Corporation, ECLIPSE L200), and the delamination state was evaluated on a 5-point scale. The percentage of the total area of ​​the cured product of the circuit connection material that had delaminated from the glass substrate was determined, and a delamination percentage of less than 5% of the total was rated as "5", a delamination percentage of 5% or more but less than 10% was rated as "4", a delamination percentage of 10% or more but less than 30% was rated as "3", a delamination percentage of 30% or more but less than 50% was rated as "2", and a delamination percentage of 50% or more was rated as "1".

[0131] <Evaluation of storage stability (after preservation treatment)> Using the above-mentioned film-like circuit connection material treated at 40°C for 3 days, a connection body was fabricated in the same manner as described above, and the adhesive strength and peel resistance were measured and evaluated using the same method as described above.

[0132] [Table 2] [Explanation of Symbols]

[0133] 1...Connector, 5...Insulating adhesive layer, 7...Conductive particles, 8...Support, 10...Connecting member, 11...Insulating layer, 20...First circuit member, 21...First circuit board, 21a...Main surface, 22...First circuit electrode, 30...Second circuit member, 31...Second circuit board, 31a...Main surface, 32...Second circuit electrode, 40...Film-like circuit connection material, 100...Laminated film.

Claims

1. An adhesive composition comprising (a) a thermoplastic resin, (b) a radical polymerizable compound, and (c) a radical polymerization initiator, The (a) thermoplastic resin contains (a-1) polyurethane resin and (a-2) phenoxy resin, The (a-1) polyurethane resin is an ester urethane compound, The (b) radical polymerizable compound includes (b-1) a radical polymerizable compound having a structure in which an isocyanate group is protected by a blocking agent, and (b-2) a radical polymerizable compound having a phosphate group. An adhesive composition in which the content of the radical polymerizable compound having the (b-2) phosphate group is 1.6% by mass or less, based on the total amount of the adhesive composition.

2. The adhesive composition according to claim 1, wherein the mass ratio of the (a-1) polyurethane resin to the (a-2) phenoxy resin is 8:2 to 2:

8.

3. The adhesive composition according to claim 1, wherein the radical polymerizable compound having a structure in which the (b-1) isocyanate group is protected by a blocking agent is a (meth)acrylate compound having a pyrazole-blocked isocyanate group.

4. A circuit connection material comprising the adhesive composition according to any one of claims 1 to 3.

5. The circuit connection material according to claim 4, further containing conductive particles.

6. A first circuit member having a first circuit electrode formed on the main surface of a first circuit board, A second circuit electrode is formed on the main surface of a second circuit board, and a second circuit member is arranged such that the second circuit electrode and the first circuit electrode face each other. The device comprises a connecting member provided between the first circuit member and the second circuit member, which electrically connects the first circuit member and the second circuit member, A connecting body wherein the connecting member includes a cured product of the adhesive composition described in any one of claims 1 to 3.

7. The connector according to claim 6, wherein at least one of the first circuit board and the second circuit board is a glass substrate.

Images