Adhesive composition and adhesive sheet, laminate and printed wiring board containing the same

Abstract

This invention provides an adhesive composition exhibiting excellent heat resistance, bonding strength, relative permittivity, low dielectric loss tangent, and superior dielectric properties, as well as adhesive sheets, laminates, and printed circuit boards containing this adhesive composition. As a solution, an adhesive composition containing polyester resin, compound A, and compound B is provided. Compound A is a compound having a terminal unsaturated hydrocarbon group and a 5% weight reduction temperature of 260°C or higher; compound B is a compound having an epoxy group and a terminal unsaturated hydrocarbon group.

Description

Technical Field

[0001] This invention relates to an adhesive composition. More specifically, it relates to an adhesive composition for bonding resin substrates to resin substrates or metal substrates. In particular, it relates to an adhesive composition for flexible printed circuit boards (hereinafter referred to as FPCs), and adhesive sheets, laminates, and printed circuit boards containing said adhesive composition. Background Technology

[0002] Copolyesters are widely used as raw materials for resin compositions such as coating agents, inks, and adhesives, and are typically composed of polycarboxylic acids and polyols. The selection and combination of polycarboxylic acids and polyols can be freely controlled, affecting the softness and molecular weight.

[0003] Copolyesters have excellent adhesion to copper-containing metals and can be mixed with curing agents such as epoxy resins for use as adhesives for FPCs, etc. (e.g., Patent Document 1).

[0004] Due to its excellent flexibility, flexible printed circuit boards (FPCs) can meet the demands of multifunctionality and miniaturization in personal computers, smartphones, and other devices, and are therefore widely used to house electronic circuit boards within confined and complex interiors. In recent years, the miniaturization, weight reduction, high density, and high power of electronic devices have placed increasingly higher demands on the performance of circuit boards (electronic circuit boards). In particular, the increasing speed of transmission in FPCs has led to the use of high-frequency signals. Consequently, the requirement for low dielectric properties (low dielectric constant, low dielectric loss tangent) in the high-frequency region is also increasing for FPCs. To achieve such low dielectric properties, a solution is needed to reduce the dielectric loss of the FPC substrate and adhesive. For substrates used in FPCs, in addition to existing materials such as polyimide (PI) and polyethylene terephthalate (PET), substrate films with low dielectric properties such as liquid crystal polymers (LCP) and syndiotactic polystyrene (SPS) have been proposed. As for adhesives, the development of adhesives using polyphenylene ether (PPE) (Patent Document 2) and the like is underway.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Publication No. 6-104813

[0008] Patent Document 2: WO2020 / 196718 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] However, the copolyester described in Patent Document 1 has a high relative permittivity and dielectric loss tangent, and does not possess the aforementioned low dielectric properties, thus making it unsuitable for FPCs in the high-frequency region. Furthermore, the adhesive described in Patent Document 2 is hardly considered to possess excellent heat resistance as an FPC adhesive, and its dielectric properties are also insufficient.

[0011] This invention was made in response to the problems in the prior art. Specifically, the object of this invention is to provide an adhesive composition with excellent heat resistance, bonding strength, low relative permittivity and dielectric loss tangent, and excellent dielectric properties, as well as adhesive sheets, laminates, and printed circuit boards containing this adhesive composition.

[0012] Technical means to solve the problem

[0013] After conducting in-depth research, the inventors discovered that the above-mentioned technical problems can be solved by the means shown below, thereby realizing the present invention.

[0014] That is, the present invention is composed of the following elements.

[0015] [1] An adhesive composition comprising polyester resin, compound A and compound B, wherein compound A is a compound having a terminal unsaturated hydrocarbon group and a 5% weight reduction temperature of 260°C or higher; and compound B is a compound having an epoxy group and a terminal unsaturated hydrocarbon group.

[0016] [2] According to the adhesive composition of [1], the compound A is a compound having an aromatic ring structure or an alicyclic structure as a structural unit.

[0017] [3] According to the adhesive composition of [1], the compound A is a polyphenylene ether or a phenolic resin having terminal unsaturated hydrocarbon groups.

[0018] [4] According to the adhesive compositions described in [1] to [3], the compound B is a compound having an isocyanurate ring.

[0019] [5] According to the adhesive composition described in [1] to [4], the dielectric loss tangent of the polyester resin is 0.005 or less.

[0020] [6] The adhesive composition according to [1] to [5] further contains polycarbodiimide.

[0021] [7] An adhesive sheet having an adhesive layer composed of the adhesive compositions described in [1] to [6].

[0022] [8] A laminate having an adhesive layer composed of the adhesive compositions described in [1] to [6].

[0023] [9] A printed circuit board containing the laminate of [8] as a constituent element.

[0024] The effects of the invention

[0025] The adhesive composition of the present invention exhibits excellent dielectric properties, bond strength, and solder heat resistance. Therefore, it is suitable for adhesives, adhesive sheets, laminates, and printed circuit boards used in high-frequency applications. Detailed Implementation

[0026] Hereinafter, one embodiment of the present invention will be described in detail. However, the present invention is not limited thereto, and various modifications can be made within the known scope.

[0027] <Adhesive Composition>

[0028] The adhesive composition of the present invention is an adhesive composition containing polyester resin, compound A, and compound B. Here, compound A and compound B are respectively the compounds described below.

[0029] Compound A: A compound having a terminal unsaturated hydrocarbon group and a 5% weight reduction temperature above 260°C;

[0030] Compound B: A compound having an epoxy group and a terminal unsaturated hydrocarbon group.

[0031] By reacting the terminal unsaturated hydrocarbon groups of compounds A and B with each other, curing can be carried out without generating hydroxyl groups that degrade dielectric properties, thus achieving both excellent solder heat resistance and dielectric properties.

[0032] <Polyester Resin>

[0033] The polyester resin in this invention is composed of a chemical structure obtained by condensation of polycarboxylic acid components and polyol components, wherein the polycarboxylic acid components and polyol components are each composed of one or more selected components.

[0034] The polycarboxylic acid component constituting the polyester resin of the present invention is preferably an aromatic polycarboxylic acid or an alicyclic polycarboxylic acid, more preferably an aromatic dicarboxylic acid or an alicyclic dicarboxylic acid. Excellent dielectric properties can be exhibited by using only aromatic polycarboxylic acids or alicyclic polycarboxylic acids as the polycarboxylic acid component.

[0035] The aromatic dicarboxylic acid component is not particularly limited, and terephthalic acid, isophthalic acid, phthalic acid, 4,4'-dicarboxybiphenyl, sodium isophthalate-5-sulfonate, naphthalic acid, or their esters can be used. Naphthalic acid is preferred, as it exhibits excellent dielectric properties. More preferably, it contains 50 mol% or more of naphthalic acid as a polycarboxylic acid component constituting the polyester resin, even more preferably 70 mol% or more, and particularly preferably 80 mol% or more, which can improve dielectric properties.

[0036] As an alicyclic dicarboxylic acid, there are no particular limitations, and 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hydrogenated naphthalic acid, etc. can be used.

[0037] The polyol constituting the polyester resin of the present invention is not particularly limited, and ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2-methyl-2-ethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-n-propyl- The polyols used may include aliphatic polyols such as 1,3-propanediol, 2,2-di-n-propyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,2-di-n-butyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, and dimerized diols; alicyclic polyols such as 1,4-cyclohexanediethanol and tricyclodecanediethanol; and polyalkylene ether diols such as polytetramethylene glycol and polypropylene glycol. One or more of these polyols may be used. Dimerized diols and tricyclodecanediethanol are preferred as they exhibit excellent dielectric properties. More preferably, the polyols containing a total of 20 mol% or more of dimerized diol and tricyclodecanediethanol as the polyol component constituting the polyester resin are preferred; even more preferably, they contain 30 mol% or more; and particularly preferably, they contain 40 mol% or more, which can improve dielectric properties. Dimer diol and tricyclodecanediethanol may be contained in only one of them or in both.

[0038] In the polyester resin of the present invention, a polycarboxylic acid component with three or more constituents and / or a polyol component with three or more constituents can be copolymerized. Examples of polycarboxylic acid components with three or more constituents include aromatic carboxylic acids such as trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, trimellitic acid, trimellitic anhydride (TMA), and pyromellitic anhydride (PMDA), and aliphatic carboxylic acids such as 1,2,3,4-butanetetracarboxylic acid; one or more of these can be used. Examples of polyol components with three or more constituents include glycerol, trimethylolpropane, trimethylolethane, pentaerythritol, α-methylglucose, mannitol, and sorbitol; one or more of these can be used. However, when the copolymerization amount of polycarboxylic acid components with three or more constituents and / or polyol components with three or more constituents increases, the dielectric properties of the polyester resin deteriorate, which is therefore not preferred.

[0039] As a method for the polycondensation reaction to manufacture the polyester resin of the present invention, there are, for example, the following methods: 1) heating a polycarboxylic acid and a polyol in the presence of a known catalyst, followed by a dehydration esterification step, to carry out a polyol removal / polycondensation reaction; 2) heating a polycarboxylic acid ester and a polyol in the presence of a known catalyst, followed by a transesterification step, to carry out a polyol removal / polycondensation reaction; 3) a depolymerization method. In methods 1) and 2), part or all of the acid component can be replaced with an anhydride.

[0040] In manufacturing the polyester resin of the present invention, conventionally known polymerization catalysts can be used, such as titanium compounds like tetrabutyl titanate, tetraisopropyl titanate, and titanium acetylacetone oxide; antimony compounds like antimony trioxide and antimony tributoxy; germanium compounds like germanium oxide and germanium tetrabutoxy; and acetates of magnesium, iron, zinc, manganese, cobalt, aluminum, etc. One or more of these catalysts can be used.

[0041] The number-average molecular weight of the polyester resin of the present invention is preferably 5,000 or more, more preferably 10,000 or more. Furthermore, it is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 30,000 or less. Since a number-average molecular weight within this range provides convenient handling when dissolved in a solvent and excellent dielectric properties, it is preferred.

[0042] The polyester resin of the present invention preferably has a dielectric loss tangent of 0.005 or less at 10 GHz. More preferably, it is 0.004 or less, and even more preferably 0.003 or less. While the lower limit is not particularly limited, it is 0.001 or more for practical purposes. As described above, methods containing naphthalenedicarboxylic acid, dimer diol, and tricyclodecanediethanol as structural units of the polyester resin can be used to set the dielectric loss tangent of the polyester resin within the aforementioned range.

[0043] <Compound A>

[0044] Compound A of the present invention is a compound having a terminal unsaturated hydrocarbon group and a 5% weight reduction temperature of 260°C or higher. Due to the presence of the terminal unsaturated hydrocarbon group, the crosslinking density can be increased and the heat resistance of the solder can be improved through reaction with compound B (described later). Furthermore, since no hydroxyl groups that deteriorate dielectric properties are generated after the reaction, an adhesive with excellent dielectric properties can be formed. For the terminal unsaturated hydrocarbon group, having two or more in one molecule further increases the crosslinking density, and is therefore preferred. Here, the terminal unsaturated hydrocarbon group refers to groups with a CH2=C structure, such as vinyl, vinylidene, allyl, acryloyl, methacryl, and styryl.

[0045] The 5% weight loss temperature of compound A needs to be 260°C or higher. Preferably, it is 270°C or higher, more preferably 280°C or higher, and even more preferably 290°C or higher. With a 5% weight loss temperature above the above values, soldering can be performed without causing appearance defects, even when using temperatures exceeding the melting point of solder.

[0046] Compound A preferably has an aromatic ring structure or an alicyclic structure as its structural unit. Using an aromatic ring structure or an alicyclic structure as the structural unit improves the heat resistance of the solder and also provides excellent dielectric properties. Preferably, an aromatic ring structure or an alicyclic structure forms the backbone of compound A, and polyphenylene ether or phenolic resin is preferred. Specific examples of polyphenylene ether with terminal unsaturated hydrocarbon groups include SABIC's SA-9000 and Mitsubishi Gas Chemical's OPE-2St. Furthermore, an example of a phenolic resin with terminal unsaturated hydrocarbon groups is Resitop FTC-809AE from Kunei Chemical Industry Co., Ltd.

[0047] The number average molecular weight of compound A is preferably 500 or more, more preferably 1000 or more. Furthermore, it is preferably 100,000 or less, more preferably 10,000 or less, and even more preferably 5,000 or less. When the number average molecular weight is within the above-mentioned range, it exhibits good solubility in solvents and can form a uniform adhesive coating.

[0048] Relative to 100 parts by weight of polyester resin, the content of compound A in the adhesive composition of the present invention is preferably 1 part by weight or more, more preferably 10 parts by weight or more. Furthermore, it is preferably 100 parts by weight or less, more preferably 50 parts by weight or less. When the content is within the above range, both excellent adhesion and solder heat resistance can be achieved.

[0049] <Compound B>

[0050] Compound B of the present invention is a compound having an epoxy group and a terminal unsaturated hydrocarbon group. Because it has an epoxy group, it can react with polyester resins and polycarbodiimide (described later), and because it has a terminal unsaturated hydrocarbon group, it can react with compound A. Therefore, the crosslinking density between these compounds is further increased, thereby achieving excellent solder heat resistance. Here, the terminal unsaturated hydrocarbon group refers to a group having a CH2=C structure, such as vinyl, vinylidene, allyl, acryloyl, methacryl, styryl, etc.

[0051] Compound B preferably has a ring structure. When compound B has a ring structure, its heat resistance is improved, and its dielectric properties are also excellent. From the viewpoint of heat resistance, the ring structure of compound B is preferably an aromatic ring structure or an isocyanurate ring structure. Specific examples of such compounds B include diallyl monoglycidyl isocyanurate and diglycidyl monoallyl isocyanurate. By using them, the crosslinking density can be increased, thereby improving the heat resistance of the solder.

[0052] The molecular weight of compound B is preferably 500 or less, more preferably 400 or less. Since the molecular weight is below this value, its solubility in solvents and its reactivity with compound A, polyester resin, and polycarbodiimide are all improved, which can increase the crosslinking density and enhance the heat resistance of the solder.

[0053] The content of compound B in the adhesive composition of the present invention is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of polyester resin. Furthermore, it is preferably 50 parts by mass or less, more preferably 20 parts by mass or less. When the content of compound B is within the above range, both excellent adhesion and solder heat resistance can be achieved. Furthermore, the content of compound B is preferably set to 1 equivalent or more of terminal unsaturated hydrocarbon groups relative to the terminal unsaturated hydrocarbon groups of compound A. By setting it to 1 equivalent or more, the crosslinking density can be increased, exhibiting excellent solder heat resistance.

[0054] Free radical initiators

[0055] The adhesive composition of the present invention preferably contains a free radical initiator. Although the adhesive composition of the present invention can also react compound A and compound B by heating, the free radicals generated by the free radical initiator can efficiently react the terminal unsaturated hydrocarbon groups of compound A and compound B with each other, increase the crosslinking density, and improve the heat resistance and dielectric properties of the solder. There are no particular limitations on the free radical initiator, but organic peroxides are preferred. Examples of organic peroxides include: di-tert-butyl phthalate peroxide, tert-butyl hydroperoxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxypentanoate, methyl ethyl ketone peroxide, di-tert-butyl peroxide, lauroyl peroxide, etc.; azo nitrile compounds such as azobisisobutyronitrile and azobisisopropionitrile, etc.

[0056] The half-life temperature of the free radical initiator used in this invention is preferably 140°C or higher. By setting the half-life temperature of 140°C or higher, the initiation of free radical reaction can be prevented when the solvent of the adhesive composition varnish evaporates, thereby producing adhesive sheets, thus exhibiting excellent adhesive properties.

[0057] Relative to 100 parts by mass of compound A, the content of the free radical initiator used in this invention is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more. Furthermore, it is preferably 50 parts by mass or less, more preferably 10 parts by mass or less. By setting the content within the above range, optimal crosslinking density can be achieved, resulting in a combination of adhesion and solder heat resistance.

[0058] <Polycarbodiimide>

[0059] The adhesive composition of the present invention may contain polycarbodiimide. There are no particular limitations on the polycarbodiimide, as long as it contains two or more carbodiimide bonds within its molecule. By using polycarbodiimide, the hydroxyl groups of the polyester resin react with the carbodiimide bonds, thereby improving heat resistance and adhesion. Furthermore, the elimination of hydroxyl groups through reaction with the hydroxyl groups of the polyester resin also contributes to the improvement of dielectric properties.

[0060] In the adhesive composition of the present invention, the content of polycarbodiimide is preferably 1 part by mass or more, more preferably 3 parts by mass or more, relative to 100 parts by mass of polyester resin. By setting it to the lower limit or above, the crosslinking density can be increased, and the solder heat resistance becomes good. Furthermore, it is preferably 20 parts by mass or less, more preferably 10 parts by mass or less. By setting it to the upper limit or below, excellent solder heat resistance and low dielectric properties can be exhibited. That is, when the content of polycarbodiimide is within the above range, an adhesive composition with excellent solder heat resistance and low dielectric properties can be obtained.

[0061] <Epoxy Resin>

[0062] The adhesive composition of the present invention may contain an epoxy resin. As for the epoxy resin used in the present invention, there is no particular limitation as long as it has epoxy groups in its molecule; preferably, it is an epoxy resin having two or more epoxy groups in its molecule. Without specific limitation, at least one type selected from the group consisting of biphenyl-type epoxy resins, naphthalene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, phenolic varnish-type epoxy resins, alicyclic epoxy resins, dicyclopentadiene-type epoxy resins, tetraglycidyl diaminodiphenylmethane, triglycidyl p-aminophenol, tetraglycidyl diaminomethylcyclohexanone, N,N,N',N'-tetraglycidyl-m-phenylenediamine, and epoxidized polybutadiene is preferred. Preferably, it is N,N,N',N'-tetraglycidyl-m-phenylenediamine, biphenyl-type epoxy resin, phenolic varnish-type epoxy resin, dicyclopentadiene-type epoxy resin, or epoxidized polybutadiene. More preferably, it is N,N,N',N'-tetraglycidyl-m-phenylenediamine, which can exhibit excellent adhesion.

[0063] In the adhesive composition of the present invention, the content of epoxy resin is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, and even more preferably 1 part by weight or more, relative to 100 parts by weight of polyester resin. By setting the content to the lower limit value or above, sufficient curing effect can be obtained, exhibiting excellent adhesion and solder heat resistance. Furthermore, it is preferably 10 parts by weight or less, more preferably 5 parts by weight or less. By setting it to the upper limit value or below, the pot life and low dielectric properties become good. That is, by setting it within the above range, an adhesive composition that has excellent low dielectric properties in addition to having adhesion, solder heat resistance, and pot life can be obtained.

[0064] The adhesive composition of the present invention may further contain an organic solvent. The organic solvent used in the present invention is not particularly limited as long as it is capable of dissolving the polyester resin, compound A, and compound B. Specifically, the following solvents may be used: aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, octane, and decane; alicyclic hydrocarbons such as cyclohexane, cyclohexene, methylcyclohexane, and ethylcyclohexane; halogenated hydrocarbons such as trichloroethylene, dichloroethylene, chlorobenzene, and chloroform; alcohol solvents such as methanol, ethanol, isopropanol, butanol, pentanol, hexanol, propylene glycol, and phenol; acetone, methyl isobutyl ketone, methyl ethyl ketone, pentanol, hexanone, cyclohexanone, and isophorone. Ketone solvents such as acetophenone, cellosolvers such as methyl and ethyl cellosolvers, ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl propionate, and butyl formate, and glycol ether solvents such as ethylene glycol mono-n-butyl ether, ethylene glycol mono-isobutyl ether, ethylene glycol mono-tert-butyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-isobutyl ether, triethylene glycol mono-n-butyl ether, and tetraethylene glycol mono-n-butyl ether can be used, either alone or in combination of two or more. From the viewpoint of processing environment and drying properties, methylcyclohexane and toluene are particularly preferred.

[0065] The organic solvent is preferably in the range of 100 to 1000 parts by weight relative to 100 parts by weight of polyester resin. Setting it above the lower limit improves both the liquid state and shelf life. Furthermore, setting it below the upper limit is advantageous from the perspectives of manufacturing and transportation costs.

[0066] Furthermore, the adhesive composition of the present invention may also contain other components as needed. Specific examples of such components include flame retardants, tackifiers, fillers, and silane coupling agents.

[0067] Flame retardants

[0068] The adhesive composition of the present invention can also be mixed with flame retardants as needed. As flame retardants, bromine-based, phosphorus-based, nitrogen-based, and metal hydroxides can be used. Among these, phosphorus-based flame retardants are preferred, and known phosphorus-based flame retardants such as phosphate esters (e.g., trimethyl phosphate, triphenyl phosphate, tricresyl phosphate), phosphates (e.g., aluminum phosphinate), and phosphazenes can be used. These flame retardants can be used alone or in combination of any two or more. When containing a flame retardant, the amount of flame retardant is preferably in the range of 1 to 200 parts by mass relative to a total of 100 parts by mass of the polyester resin, compound A, and compound B; more preferably, in the range of 5 to 150 parts by mass; and most preferably, in the range of 10 to 100 parts by mass. Within this range, flame retardancy can be exhibited while maintaining adhesion, solder heat resistance, and electrical properties.

[0069] <Tackifier>

[0070] The adhesive composition of the present invention can also be mixed with a tackifier as needed. Examples of tackifiers include polyterpene resins, rosin-based resins, aliphatic petroleum resins, alicyclic petroleum resins, copolymer petroleum resins, styrene resins, and hydrogenated petroleum resins, which are used to improve adhesive strength. These tackifiers can be used alone or in combination of two or more. When containing a tackifier, it is preferable to contain 1 to 200 parts by weight of the tackifier relative to a total of 100 parts by weight of the polyester resin, compound A, and compound B; more preferably, 5 to 150 parts by weight; and most preferably, 10 to 100 parts by weight. Within these ranges, the tack-enhancing effect can be achieved while maintaining adhesion, solder heat resistance, and electrical properties.

[0071] <packing>

[0072] The adhesive composition of the present invention can also be mixed with fillers as needed. Examples of organic fillers include powders of heat-resistant resins such as polyimide, polyamide-imide, fluororesin, and liquid crystal polyester. Examples of inorganic fillers include, for instance, silica (SiO2), alumina (Al2O3), titanium dioxide (TiO2), tantalum oxide (Ta2O5), zirconium oxide (ZrO2), silicon nitride (Si3N4), boron nitride (BN), calcium carbonate (CaCO3), calcium sulfate (CaSO4), zinc oxide (ZnO), magnesium titanate (MgO·TiO2), barium sulfate (BaSO4), organobentonite, clay, mica, aluminum hydroxide, and magnesium hydroxide. Among these, silica is preferred considering ease of dispersion and the improvement in heat resistance.

[0073] Hydrophobic and hydrophilic silica are commonly known as silica. Hydrophobic silica treated with dimethyldichlorosilane, hexamethyldisilazane, octylsilane, etc., is preferred here to impart moisture resistance. When mixing silica, the mixing amount is preferably 0.05 to 30 parts by mass relative to a total of 100 parts by mass of the copolyester, compound A, and compound B. Setting the amount above the lower limit further enhances heat resistance. Furthermore, setting the amount below the upper limit suppresses poor silica dispersion and excessively high solution viscosity, resulting in better processability.

[0074] <Silane Coupling Agent>

[0075] The adhesive composition of the present invention can also be mixed with a silane coupling agent as needed. Since the adhesion and heat resistance properties to metals are improved by mixing with a silane coupling agent, this is highly preferred. There are no particular limitations on the silane coupling agent; examples include silane coupling agents with unsaturated groups, silane coupling agents with epoxy groups, and silane coupling agents with amino groups. Among these, from the viewpoint of heat resistance, silane coupling agents with epoxy groups such as γ-epoxypropoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltriethoxysilane are further preferred. When mixing the silane coupling agent, the mixing amount is preferably 0.5 to 20 parts by mass relative to a total of 100 parts by mass of the polyester resin, compound A, and compound B. Within this range, the heat resistance and adhesion of the solder can be improved.

[0076] <Layered Body>

[0077] The laminate of the present invention is a laminate in which an adhesive composition is laminated on a substrate (a two-layer laminate of substrate / adhesive layer), or a laminate further bonded to a substrate (a three-layer laminate of substrate / adhesive layer / substrate). Here, the adhesive layer refers to a layer of adhesive composition after the adhesive composition of the present invention has been applied to the substrate and dried. The laminate of the present invention can be obtained by applying and drying the adhesive composition of the present invention on various substrates using conventional methods, and by further laminating other substrates.

[0078] <Substrate>

[0079] In this invention, the term "substrate" is not particularly limited to any substrate that can be coated, dried, and form an adhesive layer with the adhesive composition of this invention. Examples include resin substrates such as film resins, metal substrates such as metal plates and metal foils, and paper.

[0080] Examples of resin substrates include polyester resins, polyamide resins, polyimide resins, polyamide-imide resins, liquid crystal polymers, polyphenylene sulfide, syndiotactic polystyrene, polyolefin resins, and fluorinated resins. A film-like resin (hereinafter also referred to as a substrate film) is preferred.

[0081] As the metal substrate, any existing known conductive material suitable for use on circuit boards can be used. Examples of materials include various metals such as SUS, copper, aluminum, iron, steel, zinc, and nickel, their alloys, electroplated products, and metals treated with zinc or chromium compounds. Metal foil is preferred, and copper foil is more preferred. The thickness of the metal foil is not particularly limited, but 1 μm or more is preferred, more preferably 3 μm or more, and even more preferably 10 μm or more. Furthermore, 50 μm or less is preferred, more preferably 30 μm or less, and even more preferably 20 μm or less. When the thickness is too thin, it may be difficult to obtain sufficient electrical performance of the circuit; on the other hand, when the thickness is too thick, the processing efficiency during circuit fabrication may decrease. The metal foil is usually used in a roll form. The form of the metal foil used in manufacturing the printed circuit board of the present invention is not particularly limited. When using strip-shaped metal foil, its length is not particularly limited. Furthermore, its width is not particularly limited, but is preferably around 250 to 500 cm. The surface roughness of the substrate is not particularly limited, but is preferably 3 μm or less, more preferably 2 μm or less, and even more preferably 1.5 μm or less. Furthermore, from a practical standpoint, it is preferably 0.3 μm or more, more preferably 0.5 μm or more, and even more preferably 0.7 μm or more.

[0082] Examples of paper products include woodfree paper, kraft paper, roll paper, and glassine paper. Examples of composite materials include glass epoxy resin.

[0083] Considering the adhesion and durability of the adhesive composition, polyester resin, polyamide resin, polyimide resin, polyamide-imide resin, liquid crystal polymer, polyphenylene sulfide, syndiotactic polystyrene, polyolefin resin, fluorinated resin, SUS steel plate, copper foil, aluminum foil, or glass epoxy resin are preferred as the substrate.

[0084] <Adhesive Sheets>

[0085] In this invention, the adhesive sheet refers to a sheet in which the laminate and the release substrate are layered together by an adhesive composition. Specific configurations include: laminate / adhesive layer / release substrate or release substrate / adhesive layer / laminate / adhesive layer / release substrate. The laminated release substrate functions as a protective layer for the substrate. Furthermore, by using the release substrate, the release substrate can be demolded from the adhesive sheet, and the adhesive layer can be further transferred onto other substrates.

[0086] The adhesive sheet of the present invention can be obtained by applying and drying the adhesive composition of the present invention onto various laminates using conventional methods. Furthermore, after drying, when a release substrate is attached to the adhesive layer, it can be wound without substrate contamination, exhibiting excellent processability and excellent preservation due to the protection of the adhesive layer, making it easy to use. Additionally, if other release substrates are attached as needed after coating and drying on a release substrate, the adhesive layer can also be transferred to other substrates.

[0087] <Molding Substrate>

[0088] There are no particular limitations on the release substrate. Examples include substrates with clay, polyethylene, polypropylene, or other pore-filling agents coated on both sides of woodfree paper, kraft paper, roll paper, glassine paper, etc., and then coated with silicone-based, fluorine-based, or alkyd-based release agents. Additionally, examples include various individual olefin films such as polyethylene, polypropylene, ethylene-α-olefin copolymer, and propylene-α-olefin copolymer, as well as films coated with the aforementioned release agents on polyethylene terephthalate (PET) films. Considering the release force between the release substrate and the adhesive layer, and the negative impact of silicone on electrical properties, it is preferable to use a release substrate where polypropylene is used to fill pores on both sides of woodfree paper before applying an alkyd-based release agent, or a release substrate where an alkyd-based release agent is applied to polyethylene terephthalate.

[0089] It should be noted that the method for coating the adhesive composition onto the substrate in this invention is not particularly limited, and examples include comma coaters, reverse roller coaters, etc. Alternatively, the adhesive layer can be directly applied to the rolled copper foil or polyimide film of the printed circuit board constituent material, or applied by transfer method, as needed. The thickness of the adhesive layer after drying can be appropriately varied as needed, and is preferably in the range of 5 to 200 μm. By setting the adhesive film thickness to 5 μm or more, sufficient adhesive strength can be obtained. Furthermore, by setting it to 200 μm or less, the amount of residual solvent in the drying process is easily controlled, and bubbling is less likely to occur during the pressing process of printed circuit board manufacturing. The drying conditions are not particularly limited, but the residual solvent rate after drying is preferably 1% by mass or less. By setting it to 1% by mass or less, foaming of residual solvent during printed circuit board pressing can be suppressed, making it difficult for bubbling to occur.

[0090] Printed Circuit Boards

[0091] The printed circuit board of this invention comprises a laminate formed of metal foil forming conductive circuits and a resin substrate as its constituent elements. For example, flexible substrates, rigid substrates, and encapsulation substrates are included. The printed circuit board can be manufactured, for example, using a metal-clad laminate and by conventionally known methods such as the subtractive process. Flexible printed circuit boards (FPCs), flat cables, and tape-and-reel (TAB) circuit boards, which, as needed, partially or completely cover the conductive circuits formed of metal foil using a cover film, screen printing ink, etc., are collectively referred to as printed circuit boards.

[0092] The printed circuit board of the present invention can be configured with any layered structure that can be used in printed circuit boards. For example, it can be configured as a printed circuit board consisting of four layers: a substrate film layer, a metal foil layer, an adhesive layer, and a cover film layer. Furthermore, for example, it can also be configured as a printed circuit board consisting of five layers: a substrate film layer, an adhesive layer, a metal foil layer, an adhesive layer, and a cover film layer.

[0093] Furthermore, depending on the needs, it can also be configured as a structure with two or more of the above-mentioned printed circuit boards stacked together.

[0094] The adhesive composition of the present invention is applicable to various adhesive layers of printed circuit boards. In particular, when used as an adhesive, the adhesive composition of the present invention exhibits high adhesion not only to existing polyimide, polyester film, and copper foil constituting printed circuit boards, but also to low-polarity resin substrates such as LCP, providing reflow soldering resistance, and the adhesive layer itself possesses excellent low dielectric properties. Therefore, it is suitable as an adhesive composition for use in cover films, laminates, resin-coated copper foils, and adhesive sheets.

[0095] In the printed circuit board of the present invention, any resin film used as a substrate for conventional printed circuit boards can be used as the substrate film. Examples of resins used as the substrate film include polyester resins, polyamide resins, polyimide resins, polyamide-imide resins, liquid crystal polymers, polyphenylene sulfide, syndiotactic polystyrene, polyolefin resins, and fluorinated resins. In particular, it exhibits excellent adhesion to low-polarity group materials such as liquid crystal polymers, polyphenylene sulfide, syndiotactic polystyrene, and polyolefin resins.

[0096] <Covering film>

[0097] As the cover film, any existing known insulating film used as an insulating film for printed circuit boards can be used. For example, films manufactured from various polymers such as polyimide, polyester, polyphenylene sulfide, polyethersulfone, polyetheretherketone, aramid fiber, polycarbonate, polyarylate, polyamide-imide, liquid crystal polymer, syndiotactic polystyrene, and polyolefin resins can be used. Polyimide films or liquid crystal polymer films are more preferred.

[0098] The printed circuit board of the present invention can be manufactured using any known process other than the materials described above.

[0099] In a preferred embodiment, a semi-finished product with an adhesive layer laminated on a cover film layer is manufactured (hereinafter referred to as "cover film-side semi-finished product"). On the other hand, the following semi-finished products are manufactured: a semi-finished product in which a metal foil layer is laminated on a substrate film layer and a desired circuit pattern is formed (hereinafter referred to as "substrate film-side 2-layer semi-finished product"), or a semi-finished product in which an adhesive layer is laminated on a substrate film layer, and then a metal foil layer is laminated on top of it to form a desired circuit pattern (hereinafter referred to as "substrate film-side 3-layer semi-finished product") (hereinafter, the substrate film-side 2-layer semi-finished product and the substrate film-side 3-layer semi-finished product are collectively referred to as "substrate film-side semi-finished product"). By bonding the cover film-side semi-finished product and the substrate film-side semi-finished product obtained therefrom, a 4-layer or 5-layer printed circuit board can be obtained.

[0100] The substrate film side semi-finished product can be obtained by, for example, a manufacturing method comprising two steps (A) and (B), wherein: (A) a step of coating the resin solution constituting the substrate film onto the metal foil and performing initial drying of the coating film; and (B) a step of heat-treating and drying the laminate of the metal foil and the initially dried coating film obtained by (A) (hereinafter referred to as the "heat treatment / solvent removal step").

[0101] The circuitry in the metal foil layer can be formed using existing, known methods. Both additive and subtractive methods can be used. Subtractive methods are preferred.

[0102] The obtained substrate film-side semi-finished product can be directly used for bonding with the cover film-side semi-finished product. Alternatively, it can be used for bonding with the cover film-side semi-finished product after bonding and storing the release film.

[0103] The cover film side semi-finished product can be manufactured, for example, by coating the cover film with an adhesive. If necessary, a cross-linking reaction can be carried out in the coated adhesive. In a preferred embodiment, the adhesive layer can also be semi-cured.

[0104] The resulting cover film-side semi-finished product can be directly used for lamination with the substrate film-side semi-finished product. Alternatively, it can be used for lamination with the substrate film-side semi-finished product after lamination and storage of the release film.

[0105] Both the substrate film-side semi-finished product and the cover film-side semi-finished product can be laminated after being stored in rolls, for example, to manufacture a printed circuit board. As a lamination method, any method can be used, such as using a press or rollers. Alternatively, the two can be laminated while heating is being applied, using a hot press or heated roller device.

[0106] For semi-finished products on the reinforcing material side, for example, when the reinforcing material is a flexible, rollable material such as a polyimide film, it is suitable to manufacture it by coating the reinforcing material with an adhesive. Furthermore, when the reinforcing material is a rigid, non-rollable reinforcing plate such as a metal sheet like SUS or aluminum, or a plate made by curing glass fiber with epoxy resin, it is suitable to manufacture it by transferring an adhesive pre-coated to a release substrate. Additionally, if necessary, the coated adhesive can undergo a cross-linking reaction. In a preferred embodiment, the adhesive layer is semi-cured.

[0107] The resulting reinforcing material side semi-finished product can be used for direct bonding to the back of the printed circuit board. Alternatively, it can be used for bonding to the substrate film side semi-finished product after bonding and storing the release film.

[0108] The substrate film-side semi-finished product, the cover film-side semi-finished product, and the reinforcing material-side semi-finished product are all laminates for printed circuit boards in this invention.

[0109] Example

[0110] The present invention will now be described in detail with examples. It should be noted that in the present embodiments and comparative examples, the term "parts" refers to parts by mass.

[0111] <Methods for evaluating physical properties>

[0112] (Determination of polyester resin composition)

[0113] Using 400MHz 1 A hydrogen nuclear magnetic resonance (H-NMR) spectrometer (sometimes simply referred to as NMR) is used to quantify the molar ratios of the polycarboxylic acid and polyol components constituting the polyester resin. Deuterated chloroform is used as the solvent. It should be noted that when increasing the acid value of the copolyester through post-acid addition, the total amount of acid components other than those used in the post-acid addition is set to 100 mol%, and the molar ratios of each component are calculated.

[0114] (Determination of glass transition temperature)

[0115] The determination was performed using a differential scanning calorimeter (SII, DSC-200). 5 mg of the sample was placed in an aluminum-capped container and sealed, then cooled to -50°C using liquid nitrogen. The temperature was then increased to 150°C at a rate of 20°C / min. The temperature at the intersection of the extended baseline before the endothermic peak (below the glass transition temperature) and the tangent facing the endothermic peak (the tangent showing the maximum slope between the rising portion of the peak and its apex) was taken as the glass transition temperature (unit: °C).

[0116] (Determination of temperature at 5% weight reduction)

[0117] The 5% weight loss temperature was determined using a differential thermal / thermogravimetric analysis apparatus (Shimadzu Corporation, DTG-60). A 5 mg sample was placed in an aluminum pan and heated in air at a rate of 10 °C / min. The temperature at which 5% weight loss occurred due to thermal decomposition was taken as the 5% weight loss temperature (unit: °C).

[0118] (Determination of acid value)

[0119] Dissolve 0.2 g of polyester resin sample in 40 ml of chloroform, and titrate with 0.01 N potassium hydroxide ethanol solution to determine the polyester resin content. 6 g equivalent (equivalent / 10) 6 g). Phenolphthalein is used as an indicator.

[0120] (relative permittivity (ε) c and dielectric loss tangent (tanδ)

[0121] Polyester resin dissolved in a solvent was coated onto a 100 μm thick Teflon sheet with a dried thickness of 25 μm. After drying at 130°C for 3 minutes, the Teflon sheet was peeled off to obtain the test resin sheet. The prepared test resin sheet was then cut into short strips of 8 cm × 3 mm to obtain the test samples. The relative permittivity (ε) was determined using Network Analyzers (manufactured by Anritsu) at 23°C and 10 GHz via the resonant cavity perturbation method. c ) and dielectric loss tangent (tanδ).

[0122] The following are examples of the synthesis of the polyester resin used in this invention.

[0123] Synthesis example of polyester resin (c1)

[0124] 275 parts of dimethyl naphthaleneate, 5 parts of trimellitic anhydride, 264 parts of dimer diol, 125 parts of tricyclodecanediethanol, 76 parts of ethylene glycol, and 0.03 mol% tetrabutyl titanate as a catalyst relative to all acid components were added to a reaction vessel equipped with a stirrer, condenser, and thermometer. The temperature was raised from 160°C to 220°C over 4 hours, undergoing a dehydration process while simultaneously carrying out esterification. Next, a polycondensation reaction was performed, with the system pressure reduced to 5 mmHg over 20 minutes and the temperature further increased to 250°C. Then, the pressure was reduced to below 0.3 mmHg, and a polycondensation reaction was carried out for 60 minutes before the contents were removed. The resulting polyester resin (c1) was analyzed by NMR, and the results, expressed as a molar ratio, showed a copolyester of naphthaleneate / trimethylphthalic anhydride / dimer diol / tricyclodecanediethanol / ethylene glycol of 97 / 3 / 40 / 55 / 5. In addition, the glass transition temperature is 17°C and the acid value is 3 equivalents / 10. 6 g, the dielectric loss tangent at 10 GHz is 0.0035.

[0125] Synthesis example of polyester resin (c2)

[0126] 348 parts of terephthalic acid, 311 parts of isophthalic acid, 99 parts of sebacic acid, 228 parts of ethylene glycol, 313 parts of neopentyl glycol, and 0.03 mol% tetrabutyl titanate as a catalyst were added to a reaction vessel equipped with a stirrer, condenser, and thermometer. The temperature was raised from 160°C to 220°C over 4 hours, undergoing a dehydration process while simultaneously carrying out esterification. Next, a polycondensation reaction was performed, with the system pressure reduced to 5 mmHg over 20 minutes and the temperature further increased to 250°C. Then, the pressure was reduced to below 0.3 mmHg, and a polycondensation reaction was carried out for 60 minutes before the contents were removed. The resulting polyester resin (c2) was analyzed by NMR, and the results, expressed as a molar ratio, showed a copolyester with terephthalic acid / isophthalic acid / sebacic acid / ethylene glycol / neopentyl glycol ratio of 47 / 42 / 11 / 55 / 45. In addition, the glass transition temperature is 47°C and the acid value is 3 equivalents / 10. 6 g, the dielectric loss tangent at 10 GHz is 0.0076.

[0127] The following illustrates examples of adhesive compositions according to embodiments of the present invention and manufacturing examples of adhesive compositions according to comparative examples.

[0128] Use the following reagent as compound A.

[0129] (a1): SA-9000 (manufactured by SABIC, a vinyl polyphenylene ether with a number average molecular weight of 1700 and a 5% weight reduction temperature of 439°C)

[0130] (a2): FTC809AE (manufactured by Chung Yung Chemical Industry Co., Ltd., a vinyl phenolic resin with a number average molecular weight of 1400 and a 5% weight reduction temperature of 332°C)

[0131] (a3): PEGDA (manufactured by Sigma-Aldrich, polyethylene glycol diacrylate, weight average molecular weight 700, 5% weight reduction temperature 220°C)

[0132] (a4): SA-90 (manufactured by SABIC, a polyphenylene ether with hydroxyl-terminated ends (without terminal unsaturated hydrocarbon groups), number average molecular weight 1700, 5% weight reduction temperature 430°C)

[0133] Use the following reagent as compound B.

[0134] (b1): DA-MGIC (manufactured by Shikoku Chemical Industry Co., Ltd., diallyl monoglycidyl isocyanurate)

[0135] (b2): MA-DGIC (manufactured by Shikoku Chemical Industry Co., Ltd., monoallyl diglycidyl isocyanurate)

[0136] (b3): ​​Diallyl isocyanurate (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0137] Use the following reagents as additives other than those mentioned above.

[0138] V-03: Polycarbodiimide (manufactured by Nisshinbo Chemical Co., Ltd.)

[0139] Tetrad X: Epoxy resin (manufactured by Mitsubishi Gas Chemical Co., Ltd., glycidyl amine type epoxy resin)

[0140] Perbutyl P: Free radical initiator (manufactured by Nippon Oil Company, bis(1-tert-butyl-1-methylethyl)benzene, 1-minute half-life temperature 175°C)

[0141] <Example 1>

[0142] The polyester resin (c1) obtained by the above synthesis example was dissolved in toluene to prepare a toluene varnish with a solid content concentration of 40% by mass. In the toluene varnish, 20 parts of compound A (a1), 5 parts of compound B (b1), and 3 parts of Perbutyl P were mixed with 100 parts of polyester resin (c1) to prepare an adhesive composition (S1).

[0143] The obtained adhesive composition (S1) was evaluated for its relative permittivity, dielectric loss tangent, peel strength, solder heat resistance, and the flexibility of the bonded sheet. The results are shown in Table 1.

[0144] <Examples 2-14, Comparative Examples 1-5>

[0145] Except for changing the types and mixing amounts of each component of the adhesive composition to the values ​​shown in Table 1, adhesive compositions (S2) to (S19) were prepared according to the same method as in Example 1, and various evaluations were performed. The results are recorded in Table 1.

[0146] <Evaluation of Adhesive Compositions>

[0147] (relative permittivity (ε) c and dielectric loss tangent (tanδ)

[0148] The adhesive composition was applied to a 100 μm thick Teflon sheet with a dried thickness of 25 μm and dried at 130°C for 3 minutes. After curing at 180°C for 5 hours, the Teflon sheet was peeled off to obtain the test adhesive resin sheet. The obtained test adhesive resin sheet was then cut into short strips of 8 cm × 3 mm to obtain test samples. The relative permittivity (ε) was determined using Network Analyzers (manufactured by Anritsu) at 23°C and 10 GHz via the resonant cavity perturbation method. c ) and dielectric loss tangent (tanδ).

[0149] <Evaluation Criteria for Relative Permittivity>

[0150] ○: 3.0 or less

[0151] ×: Exceeds 3.0

[0152] Evaluation Criteria for Dielectric Loss Tangent

[0153] ○: Below 0.004

[0154] △: 0.004 or higher, 0.006 or lower

[0155] ×: Exceeds 0.006

[0156] (Peel strength (adhesion))

[0157] The adhesive composition was coated to a dry thickness of 25 μm onto a 12.5 μm thick polyimide film (manufactured by Kaneka Corporation, Apical (registered trademark)) and dried at 130°C for 3 minutes. The resulting adhesive film (B-grade) was then laminated onto a 18 μm thick rolled copper foil (manufactured by Nippon Steel Chemical & Materials Co., Ltd., Espanex series). For bonding, the glossy surface of the rolled copper foil was bonded to the adhesive layer, and the bonding was performed under a pressure of 2 MPa and 170°C for 280 seconds. The sample was then cured by heat treatment at 180°C for 3 hours to obtain a sample for peel strength evaluation. Peel strength was measured under the following conditions: 25°C, film removal, tensile speed of 50 mm / min, and 90° peel. This test represents the adhesive strength at room temperature.

[0158] <Evaluation Criteria>

[0159] ◎: 1.0 N / mm or higher

[0160] ○: Above 0.7 N / mm and below 1.0 N / mm

[0161] △: Above 0.5 N / mm and below 0.7 N / mm

[0162] ×: Less than 0.5 N / mm

[0163] (Solder heat resistance)

[0164] The evaluation sample was prepared using the same method as the peel strength test described above. A 2.0 cm × 2.0 cm sample was immersed in a molten tin bath at 288 °C to check for any changes in appearance, such as expansion.

[0165] <Evaluation Criteria>

[0166] ◎: No expansion occurred after 60 seconds or more.

[0167] ○: Expansion occurs when the duration is between 30 seconds and 60 seconds.

[0168] △: Expansion occurs when the duration is between 10 seconds and 30 seconds.

[0169] ×: Expansion occurs within 10 seconds.

[0170] (Flexibility of bonded sheets)

[0171] The adhesive composition was applied to a 100 μm thick Teflon (registered trademark) sheet with a dried thickness of 25 μm and dried at 130°C for 3 minutes. The coating condition was then checked when the sheet was bent 180°.

[0172] <Evaluation Criteria>

[0173] ○: No cracks

[0174] ×: Cracks present

[0175] [Table 1]

[0176]

[0177] As clearly shown in Table 1, Examples 1-14 exhibited excellent dielectric properties, peel strength, solder heat resistance, and adhesive sheet flexibility. On the other hand, in Comparative Example 1, because Compound B lacked epoxy groups, curing was insufficient, resulting in inadequate solder heat resistance. In Comparative Example 2, because Compound A lacked terminal unsaturated hydrocarbon groups, curing was insufficient, leading to inadequate solder heat resistance. Furthermore, the influence of the hydroxyl terminator resulted in a high dielectric loss tangent. In Comparative Example 3, because the 5% weight reduction temperature of Compound A was low, solder heat resistance was poor. In Comparative Example 4, because it did not contain polyester resin, the adhesive sheet was brittle, and dielectric properties, peel strength, and solder heat resistance were insufficient. In Comparative Example 5, because it did not contain Compound B, curing caused by epoxy resin occurred, resulting in poor dielectric properties.

[0178] Industrial availability

[0179] The adhesive composition of the present invention exhibits excellent heat resistance and adhesive strength, low relative dielectric constant and dielectric loss tangent, and good sheet flexibility. Therefore, it is useful as an adhesive or adhesive sheet for printed circuit boards (flexible substrates, rigid substrates, packaging substrates) suitable for high-frequency applications.

Claims

1. An adhesive composition comprising polyester resin, compound A, and compound B, wherein, Compound A is a compound with a terminal unsaturated hydrocarbon group and a 5% weight reduction temperature above 260°C; Compound B is a compound with an epoxy group and a terminal unsaturated hydrocarbon group.

2. The adhesive composition according to claim 1, wherein compound A is a compound having an aromatic ring structure or an alicyclic structure as a structural unit.

3. The adhesive composition according to claim 1, wherein compound A is a polyphenylene ether or phenolic resin having terminal unsaturated hydrocarbon groups.

4. The adhesive composition according to claim 1, wherein compound B is a compound having an isocyanurate ring.

5. The adhesive composition according to claim 1, wherein the dielectric loss tangent of the polyester resin is 0.005 or less.

6. The adhesive composition according to claim 1, further comprising polycarbodiimide.

7. An adhesive sheet having an adhesive layer formed of the adhesive composition according to any one of claims 1 to 6.

8. A laminate having an adhesive layer comprising the adhesive composition of any one of claims 1 to 6.

9. A printed circuit board comprising the laminate of claim 8 as a constituent element.

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