TW202140612A - Adhesive composition and adhesive sheet, laminate, and printed wiring board - Google Patents

Abstract

To provide an adhesive composition that exhibits superior solvent solubility, heat resistance, and adhesion strength and superior dielectric properties such as a low dielectric constant and dielectric loss tangent, as well as an adhesive sheet, a laminate, and a printed wiring board containing the same. An adhesive composition that contains a polyester and a curing agent, wherein the polyester has a polycarboxylic acid component and a polyhydric alcohol component as constituent units, a naphthalene dicarboxylic acid component constitutes at least 50 mol% out of 100 mol% of the polycarboxylic acid component, and a least one of a dimer diol component and a tricyclodecane dimethanol component is included as the polyhydric alcohol component.

Description

Adhesive composition, and adhesive sheet, laminate, and printed wiring board

The present invention relates to adhesive compositions. In more detail, it relates to the adhesive composition used for the adhesion of the resin substrate, and the resin substrate or the metal substrate. In particular, it relates to an adhesive composition for a flexible printed wiring board (hereinafter referred to as FPC), and an adhesive sheet, a laminate, and a printed wiring board having a layer formed of the adhesive composition.

Polyester has been widely used as a raw material for resin compositions used in coating agents, printing inks and adhesives, and is generally composed of polycarboxylic acids and polyols. With the selection and combination of polycarboxylic acids and polyols, flexibility and molecular weight can be freely controlled, so it has been widely used in various applications including coating applications and adhesive applications.

Among them, polyester has excellent adhesion to metals containing copper, and it has been blended with hardeners such as epoxy resin and used in adhesives such as FPC. (For example, Patent Document 1).

FPC has excellent flexibility, so it can respond to the multi-function and miniaturization of personal computers (PC), smart phones, etc., so it is often used in applications where electronic circuit boards are incorporated into narrow and complicated interiors. In recent years, the miniaturization, weight reduction, high density, and high power of electronic devices have progressed. Due to these trends, the performance requirements for wiring boards (electronic circuit boards) have increased. Especially with the increase of the transmission signal speed in FPC, the high frequency of the signal progresses. Along with this, for FPC, the requirements for low dielectric properties (low dielectric constant, low dielectric loss tangent) in the high-frequency region have increased. In addition, for the substrates used in FPC, not only the conventional polyimide (PI) and polyethylene terephthalate (PET), but also liquid crystal polymers (LCP) with low dielectric properties have been proposed. , Parallel polystyrene (SPS) and other substrate films. In order to achieve such low dielectric properties, some people have adopted methods to reduce the dielectric loss of the FPC substrate and adhesive. As for the adhesive, the development of a combination of polyolefin and epoxide (Patent Document 2), etc., has already been carried out. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 6-104813 [Patent Document 2] WO2016/047289 Publication

[The problem to be solved by the invention]

However, the polyester resin described in Patent Document 1 has a high relative dielectric constant and dielectric loss tangent, does not have the aforementioned low dielectric properties, and is not suitable for FPC in the high frequency region. In addition, the adhesive described in Patent Document 2 is hardly said to be excellent in heat resistance of the adhesive used between the reinforcing plate and the layers.

The present invention is made on the background of the subject of these conventional technologies. That is, the object of the present invention is to provide an adhesive composition having excellent solvent solubility, heat resistance, and bonding strength, low relative permittivity and dielectric loss tangent, and excellent dielectric properties, and to provide an adhesive composition containing the adhesive Adhesive composition of adhesive sheet, laminate and printed wiring board. [Means to solve the problem]

The inventors of the present case studied diligently and found that the above-mentioned problems can be solved by the means shown below, and the invention is achieved. That is, the present invention is composed of the following constitutions.

An adhesive composition containing polyester and hardener, the polyester contains polycarboxylic acid components and polyol components as structural units, and when the polycarboxylic acid component is 100 mol%, it contains more than 50 mol% The naphthalene dicarboxylic acid component contains at least one of a dimer diol component and a tricyclodecane dimethanol component as a polyol component.

The adhesive composition described above, wherein the glass transition temperature of the polyester is above -30°C.

As for the aforementioned adhesive composition, the relative dielectric constant (εc) at 10 GHz is 3.0 or less, and the dielectric loss tangent (tanδ) is 0.008 or less.

An adhesive sheet having a layer formed of the aforementioned adhesive composition.

A laminate having a layer formed of the aforementioned adhesive composition.

A printed wiring board containing the aforementioned laminate as a constituent element. [Effects of the invention]

The adhesive composition of the present invention has excellent solvent solubility, heat resistance, bonding strength, and dielectric properties. Therefore, it is suitable for FPC adhesives, adhesive sheets, laminates and printed wiring boards in the high frequency area.

Hereinafter, an embodiment of the present invention will be described in detail. However, the present invention is not limited to this, and can be implemented in various modifications within the aforementioned range.

＜Polyester＞ The polyester of the present invention is composed of a chemical structure that can be obtained as a polycondensate of a polyvalent carboxylic acid component and a polyol component, and the polyvalent carboxylic acid component and the polyol component are each composed of one or more optional components.

The polyester of the present invention contains more than 50 mol% of naphthalenedicarboxylic acid in 100 mol% of all polycarboxylic acid components contained in it. It is preferably 70 mol% or more, more preferably 80 mol% or more, particularly preferably 90 mol% or more, and 100 mol% is not a problem. By using a large amount of naphthalenedicarboxylic acid components, the dielectric properties of the polyester will be improved.

Examples of the naphthalenedicarboxylic acid component include 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, and 1,8-naphthalene Any dicarboxylic acid etc. can be used, and 2 or more types can also be used. Among them, 2,6-naphthalenedicarboxylic acid has excellent reactivity and availability during polymerization, so it is more desirable.

The polyester of the present invention may contain a polycarboxylic acid component other than the naphthalenedicarboxylic acid component. The polycarboxylic acid components other than the naphthalenedicarboxylic acid component are not particularly limited. As far as the polycarboxylic acid component is concerned, the aromatic polycarboxylic acid component or the alicyclic polycarboxylic acid component is preferably an aromatic dicarboxylic acid component or aliphatic polycarboxylic acid component. The cyclic dicarboxylic acid component is more preferable. By using an aromatic polycarboxylic acid component or an alicyclic polycarboxylic acid component as a copolymerization component, excellent dielectric properties can be exhibited.

The aromatic dicarboxylic acid component is not particularly limited, and terephthalic acid, isophthalic acid, phthalic acid, 4,4'-dicarboxybiphenyl, isophthalic acid-5-sodium sulfonate, or Their esters and so on.

The alicyclic dicarboxylic acid is not particularly limited, and 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid can be used , Tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hydrogenated naphthalene dicarboxylic acid, etc.

The polyester of the present invention must contain at least one of dimer diol and tricyclodecane dimethanol as a polyol component. The total content of dimer diol and tricyclodecane dimethanol is preferably 20 mol% or more in 100 mol% of the polyol component. It is more preferably 30 mol% or more, and still more preferably 40 mol% or more. By containing dimer diol or tricyclodecane dimethanol, the low dielectric properties of the polyester adhesive composition can be improved. When tricyclodecane dimethanol is contained, the dielectric loss tangent is particularly excellent. If the dimer diol is contained, the solvent solubility will also be improved. It is also preferable to use dimer diol and tricyclodecane diol in combination.

The above-mentioned dimer diol can be obtained by dimerizing C10-24 unsaturated fatty acids to obtain the carbon number 20-48 dimer acid and hydrogenating the carboxyl group of the saturated dimer acid It is obtained by reduction. Moreover, as a raw material of the dimer diol, vegetable oil can also be used. In addition, the dimer diol may also include a trimer of a C10-24 unsaturated fatty acid trimer, or a saturated trimer obtained by hydrogenating the trimer.

The polyester of the present invention may contain polyol components other than dimer diol and tricyclodecane dimethanol. Polyols other than dimer diol and tricyclodecane dimethanol are not particularly limited, and ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3 can be used -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-1,3-propanediol, 2,2-di-n-propyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2,2-di Aliphatic polyols such as n-butyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 1,4-cyclohexane Alicyclic polyols such as alkane dimethanol, polyalkylene ether glycols such as polytetramethylene glycol and polypropylene glycol, and the like, and one or more of these can be used.

In the polyester of the present invention, a polycarboxylic acid component with a valence of 3 or more and/or a polyol component with a valence of 3 or more may be copolymerized. Examples of trivalent or higher polycarboxylic acid components include trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, trimellitic acid, trimellitic anhydride (TMA), pyromellitic anhydride ( Aromatic carboxylic acids such as PMDA), aliphatic carboxylic acids such as 1,2,3,4-butanetetracarboxylic acid, and the like, and these can be used singly or in two or more types. Examples of trivalent or higher polyol components include glycerin, trimethylolpropane, trimethylolethane, neopentylerythritol, α-methylglucose, mannitol, and sorbitol. These can be used One or more of them. However, if the copolymerization amount of the polyvalent carboxylic acid component and/or the polyhydric alcohol component more than trivalent is large, the dielectric properties of the polyester may deteriorate, which is not ideal. When copolymerizing a polycarboxylic acid component with a valence of 3 or more and/or a polyol component with a valence of 3 or more, the total of the polycarboxylic acid component and the polyol component is 200 mol%, preferably 5 mol% or less, more preferably It is less than 4 mol%.

The glass transition temperature of the polyester of the present invention is preferably -30°C or higher, more preferably -20°C or higher. By setting the glass transition temperature above -30°C, good dielectric properties will be exhibited. In addition, the adhesiveness (adhesion) of the resin surface tends to be suppressed, and the handling of the resin will be improved. In addition, the glass transition temperature is preferably 100°C or lower. By making the glass transition temperature below 100°C, lamination can be performed even at a low temperature of about 80°C. In addition, the lower the glass transition temperature, the better the adhesive strength tends to be.

Regarding the method for the polymerization and condensation reaction of the polyester of the present invention, for example, there are the following methods: 1) Heat the polycarboxylic acid and polyol in the presence of a known catalyst, and after the dehydration esterification step, carry out depolyolization -Polycondensation reaction; 2) heating the alcohol ester body of polycarboxylic acid and polyhydric alcohol in the presence of a well-known catalyst, and after transesterification reaction, implement polyhydric alcohol-polycondensation reaction; 3) implement depolymerization and the like. In the aforementioned methods 1) and 2), part or all of the acid component may be replaced with acid anhydride.

When manufacturing the polyester of the present invention, conventionally known polymerization catalysts can be used. For example, titanium compounds such as tetra-n-butyl titanate, tetraisopropyl titanate, titanium oxyacetylacetonate, and antimony trioxide can be used. , Antimony compounds such as tributoxy antimony, germanium compounds such as germanium oxide, tetra-n-butoxy germanium, and other acetates such as magnesium, iron, zinc, manganese, cobalt, and aluminum can be used. These catalysts can be used singly or in combination of two or more.

The number average molecular weight of the polyester of the present invention is preferably 5,000 or more, more preferably 10,000 or more. In addition, it is preferably 100,000 or less, more preferably 50,000 or less, and more preferably 30,000 or less. If it is within the aforementioned range, it is easy to handle when dissolved in a solvent, the adhesive strength is good, and the dielectric properties are excellent, so it is preferable.

The acid value of the polyester of the present invention is not particularly limited, and can be appropriately designed depending on the hardener used in combination. In the case of isocyanate hardener are advised to 200eq / 10 ⁶ g or less, more preferably 100eq / 10 ⁶ g or less, and more preferably 50eq / 10 ⁶ g or less, and particularly preferably 40eq / 10 ⁶ g or less, most preferably 30eq/10 ⁶ g or less. In the case of epoxy curing, is suitably more than 20eq / 10 ⁶ g, more preferably less than 50eq / 10 ⁶ g, more preferred 100eq / 10 ⁶ g. By setting the acid value of the resin within the above-mentioned range, the effects of low dielectric properties, excellent pot life, and improvement in substrate adhesion and crosslinkability can be expected.

As a method for increasing the acid value of the polyester of the present invention, there are, for example, the following methods: (1) After the polycondensation reaction is completed, add a polyvalent carboxylic acid of more than 3 valence and/or a polyvalent carboxylic anhydride of more than 3 valence and make it react (Acid addition), (2) Acting on heat, oxygen, water, etc. during the polycondensation reaction, and deliberately implementing resin modification, etc.; these can be carried out arbitrarily. The polycarboxylic acid anhydride used in the acid addition in the aforementioned acid addition method is not particularly limited, and examples include trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, 3,3,4,4 -Benzophenone tetracarboxylic dianhydride, 3,3,4,4-biphenyltetracarboxylic dianhydride, ethylene glycol bis-anhydro trimellitate, etc., and these can be used in one or two or more types. Preferably it is trimellitic anhydride.

＜Hardening agent＞ The adhesive composition of the present invention contains polyester and hardener. As the hardener, epoxy resin, polyisocyanate, polycarbodiimide, etc. can be used. By cross-linking with these hardeners, the cohesive force of the resin can be improved and the heat resistance can be better. Among them, considering the heat resistance and the viewpoint of less influence on dielectric properties, polyisocyanate is preferable.

＜Epoxy resin＞ The epoxy resin used in the present invention is not particularly limited as long as it contains epoxy groups in the molecule, and preferably contains two or more epoxy groups in the molecule. Specifically, it is not particularly limited, and can be selected from the group consisting of biphenyl type epoxy resin, naphthalene type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, Alicyclic epoxy resin, dicyclopentadiene type epoxy resin, tetraglycidyl diamino diphenyl methane, triglycidyl p-aminophenol, tetraglycidyl diamino methyl At least one of the group consisting of cyclohexanone, N,N,N',N'-tetraepoxypropyl m-xylene diamine, and epoxy-modified polybutadiene. It is preferably biphenyl type epoxy resin, novolac type epoxy resin, dicyclopentadiene type epoxy resin or epoxy modified polybutadiene. More preferably, it is a dicyclopentadiene type epoxy resin or a novolac type epoxy resin.

In the adhesive composition of the present invention, the content of epoxy resin relative to 100 parts by mass of polyester is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, still more preferably 1 part by mass or more, and particularly preferably 2 parts by mass or more. By being above the aforementioned lower limit, a sufficient hardening effect can be obtained, and excellent adhesion and solder heat resistance can be exhibited. Moreover, it is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, still more preferably 40 parts by mass or less, and particularly preferably 35 parts by mass or less. By being below the aforementioned upper limit value, pot life and low dielectric properties become good. That is, by being within the above range, an adhesive composition having excellent low dielectric properties in addition to adhesiveness, solder heat resistance, and pot life can be obtained.

＜Polycarbodiimide＞ The polycarbodiimide used in the present invention is not particularly limited as long as it has a carbodiimide group in the molecule. It is preferably a polycarbodiimide having two or more carbodiimide groups in the molecule. By using polycarbodiimide, the carboxyl group and carbodiimide group of the polyester will react, which will increase the interaction between the adhesive composition and the substrate, and make the adhesion better.

In the adhesive composition of the present invention, the content of polycarbodiimide relative to 100 parts by mass of the polyester is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 1 part by mass or more. Preferably, it is 2 parts by mass or more. By being more than the aforementioned lower limit, the interaction with the substrate will appear, and the adhesiveness will become good. Moreover, it is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less, particularly preferably 10 parts by mass or less. By being below the aforementioned upper limit value, excellent pot life and low dielectric properties can be exhibited. That is, by being within the above range, an adhesive composition having excellent low dielectric properties in addition to adhesiveness, solder heat resistance, and pot life can be obtained.

＜Polyisocyanate＞ The polyisocyanate used in the present invention is not particularly limited as long as it is an isocyanate compound that reacts with polyester and hardens.

Examples of polyisocyanates include aromatic or aliphatic diisocyanate compounds, trivalent or higher polyisocyanate compounds, and the like. These isocyanate compounds may be any of low molecular compounds and high molecular compounds. For example, aliphatic diisocyanates such as tetramethylene diisocyanate and hexamethylene diisocyanate; aromatic diisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and xylene diisocyanate; hydrogenated diphenylmethane diisocyanate Alicyclic diisocyanates such as isocyanate, hydrogenated xylene diisocyanate, dimer acid diisocyanate, and isophorone diisocyanate; or trimers of these isocyanate compounds. In addition, an excessive amount of the aforementioned isocyanate compound may be reacted with a low-molecular-weight active hydrogen compound such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, and triethanolamine. The resulting compound contains isocyanate groups at the end. In addition, compounds having an isocyanate group at the end obtained by reacting an excess of the aforementioned isocyanate compound with various polyester polyols, polyether polyols, polyamide-based polymer active hydrogen compounds, and the like can be cited. These isocyanate compounds can be used individually or in combination of 2 or more types. Among them, the trimer of the hexamethylene diisocyanate compound is particularly preferred.

In the adhesive composition of the present invention, the content of polyisocyanate relative to 100 parts by mass of polyester is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, still more preferably 1 part by mass or more, particularly preferably 2 Parts by mass or more. By being more than the aforementioned lower limit, the interaction with the substrate will appear, and the adhesiveness will become good. Furthermore, it is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less, particularly preferably 10 parts by mass or less. By being below the aforementioned upper limit value, excellent pot life and low dielectric properties can be exhibited. That is, by being within the above range, an adhesive composition having particularly excellent low-dielectric properties in addition to adhesiveness, solder heat resistance, and pot life can be obtained.

＜Organic solvent＞ 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 can dissolve polyester and hardener. Specifically, for example, aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as hexane, heptane, octane, and decane, cyclohexane, cyclohexene, methylcyclohexane, ethyl Alicyclic hydrocarbons such as cyclohexane, halogenated hydrocarbons such as trichloroethylene, dichloroethylene, chlorobenzene, chloroform, methanol, ethanol, isopropanol, butanol, pentanol, hexanol, propylene glycol, phenol and other alcoholic solvents , Acetone, methyl isobutyl ketone, methyl ethyl ketone, pentanone, hexanone, cyclohexanone, isophorone, acetophenone and other ketone solvents, methyl serosol, ethyl serosol Ester solvents such as Celosine, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, butyl formate, etc., ethylene glycol mono-n-butyl ether, ethylene glycol mono-isobutyl ether, ethylene glycol Mono-tertiary butyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, triethylene glycol mono-n-butyl ether, tetraethylene glycol mono-n-butyl ether and other glycol ether solvents, etc. Etc. can be used singly or in combination of two or more. Especially considering the working environment and dryness, methylcyclohexane and toluene are suitable.

The organic solvent is preferably in the range of 100 to 1000 parts by mass relative to 100 parts by mass of polyester. By being more than the aforementioned lower limit value, the liquid state and pot life properties become better. In addition, by being below the aforementioned upper limit value, it is advantageous in terms of manufacturing cost and transportation cost.

In addition, the adhesive composition of the present invention may further contain other components as needed. Specific examples of such components include flame retardants, tackifiers, fillers, and silane coupling agents.

＜Flame Retardant＞ The adhesive composition of the present invention may also be blended with flame retardants as needed. Examples of flame retardants include bromine-based, phosphorus-based, nitrogen-based, and metal hydroxide compounds. Among them, phosphorus-based flame retardants are preferable, and phosphoric acid esters, such as trimethyl phosphate, triphenyl phosphate, tricresyl phosphate, etc.; phosphates, such as aluminum phosphinate, etc.; phosphazene, etc., which are well-known Phosphorus flame retardant. These can be used alone or in any combination of two or more kinds. When a flame retardant is contained, the content of the flame retardant is preferably in the range of 1 to 200 parts by mass, preferably in the range of 5 to 150 parts by mass, with respect to 100 parts by mass of the total of polyester and hardener components, and is more preferably in the range of 10 to 10 parts by mass. The range of 100 parts by mass is the best. By being within the aforementioned range, it is possible to maintain adhesion, solder heat resistance, and electrical properties while exhibiting flame retardancy.

＜Tackifier＞ The adhesive composition of the present invention may also be blended with a tackifier as needed. Tackifiers include polyterpene resins, rosin-based resins, aliphatic petroleum resins, alicyclic petroleum resins, copolymerized petroleum resins, styrene resins, and hydrogenated petroleum resins. They are used for the purpose of improving bonding strength. use. These can be used alone or in any combination of two or more kinds. When a tackifier is contained, its content is preferably in the range of 1 to 200 parts by mass relative to the total of 100 parts by mass of the polyester and hardener components, preferably in the range of 5 to 150 parts by mass, and is more preferably in the range of 10 to 100 parts by mass. The range is the best. By being within the aforementioned range, the adhesiveness, solder heat resistance, and electrical properties can be maintained while exhibiting the effect of the tackifier.

<Filler> The adhesive composition of the present invention may optionally be blended with a filler. Examples of organic fillers include powders of heat-resistant resins such as polyimide and polyimide. In addition, the inorganic fillers include, for example _{, silicon dioxide (SiO 2} ), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), and zirconium oxide (ZrO ₂ ). , Silicon nitride (Si ₃ N ₄ ), boron nitride (BN), calcium carbonate (CaCO ₃ ), calcium sulfate (CaSO ₄ ), zinc oxide (ZnO), magnesium titanate (MgO･TiO ₂ ), barium sulfate (BaSO ₄ ), organic bentonite, clay, mica, aluminum hydroxide, magnesium hydroxide, etc., among them, silicon dioxide is preferable from the viewpoint of ease of dispersion and the effect of improving heat resistance. Silicon dioxide is generally known as hydrophobic silicon dioxide and hydrophilic silicon dioxide. When considering the moisture absorption resistance, it is treated with dimethyldichlorosilane, hexamethyldisilazane, octylsilane, etc. The hydrophobic silica obtained is better. When silicon dioxide is blended, the blending amount is preferably 0.05 to 30 parts by mass relative to 100 parts by mass of the total of the polyester and hardener components. By being above the aforementioned lower limit value, better heat resistance can be exhibited. In addition, by being below the aforementioned upper limit value, poor dispersion of silica is suppressed, the solution viscosity is too high, and workability becomes better.

＜Silane Coupling Agent＞ The adhesive composition of the present invention may optionally be blended with a silane coupling agent. By blending the silane coupling agent, the adhesion to metals, heat resistance and other properties will be better, so it is very ideal. The silane coupling agent is not particularly limited, and examples thereof include those having an unsaturated group, those having an epoxy group, and those having an amine group. Among these, considering the viewpoint of heat resistance, γ-glycidoxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3 , 4-epoxycyclohexyl) ethyl triethoxy silane and other silane coupling agents with epoxy groups are more preferred. When the silane coupling agent is blended, the blending amount is preferably 0.5-20 parts by mass relative to 100 parts by mass of the total of the polyester and hardener components. By being within the aforementioned range, the solder heat resistance and adhesion can be improved.

＜Laminated body＞ The laminate system of the present invention is obtained by laminating an adhesive composition on a substrate (substrate/adhesive layer of 2 laminate), or further laminated with a substrate (substrate/adhesive Layer/substrate 3-layer laminate). Here, the adhesive layer refers to a layer of the adhesive composition obtained by coating the adhesive composition of the present invention on a substrate and drying it. The adhesive composition of the present invention is applied to various substrates according to a conventional method and dried, and other substrates are further laminated to obtain the laminate of the present invention.

＜Substrate＞ In the present invention, the substrate is not particularly limited as long as it is capable of forming an adhesive layer after coating and drying the adhesive composition of the present invention, and examples thereof include resin substrates such as film-like resins, and metals. Metal substrates such as plates and metal foils, papers, etc.

Examples of resin substrates include polyester resins, polyamide resins, polyimide resins, polyimide resins, liquid crystal polymers, polyphenylene sulfide, parapolystyrene, polyolefin resins, And fluorine resin, etc. It is preferably a film-like resin (hereinafter also referred to as a base film layer).

As the metal base material, any conventionally known conductive materials that can be used for circuit boards can be used. Examples of materials include various metals such as SUS, copper, aluminum, iron, steel, zinc, and nickel, and respective alloys, plating products, and metals processed with other metals such as zinc and chromium compounds. It is preferably a metal foil, more preferably a copper foil. The thickness of the metal foil is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, and still more preferably 10 μm or more. Moreover, it is preferably 50 μm or less, more preferably 30 μm or less, and still more preferably 20 μm or less. When the thickness is too thin, it may be difficult for the circuit to obtain sufficient electrical performance. On the other hand, when the thickness is too thick, the processing efficiency during circuit production may be reduced. Metal foil is usually provided in the form of a reel. The form of the metal foil used when manufacturing the printed wiring board of this invention is not specifically limited. When the metal foil in the form of a strip is used, its length is not particularly limited. Also, the width is not particularly limited, but it is preferably about 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 still more preferably 1.5 μm or less. Practically, it is preferably 0.3 μm or more, more preferably 0.5 μm or more, and still more preferably 0.7 μm or more.

Examples of papers include high-quality paper, kraft paper, paper rolls, cellophane, etc. In addition, as the composite material, glass epoxy resin and the like can be exemplified.

Considering the adhesion and durability of the adhesive composition, the base material is preferably polyester resin, polyamide resin, polyimide resin, polyimide resin, liquid crystal polymer, polyphenylene sulfide Ether, parallel polystyrene, polyolefin resin, fluorine resin, SUS steel plate, copper foil, aluminum foil, or glass epoxy resin.

＜Adhesive sheet＞ In the present invention, the adhesive sheet refers to a laminate obtained by laminating the aforementioned laminate and a release base material with an adhesive composition interposed therebetween. Specific structural aspects include laminate/adhesive layer/release base material, or release base material/adhesive layer/layer laminate/adhesive layer/release base material. By laminating the release base material, it functions as a protective layer of the base material. In addition, by using a release substrate, the release substrate can be released from the adhesive sheet, and then the adhesive layer can be transferred to another substrate.

The adhesive sheet of the present invention can be obtained by applying the adhesive composition of the present invention to various laminates according to a conventional method and drying. In addition, if the release substrate is attached to the adhesive layer after drying, the adhesive layer can be wound without transferring the adhesive layer to the back of the substrate. The workability is excellent, and the adhesive layer is protected at the same time, so it has excellent storage properties. , And easy to use. In addition, after coating on a release substrate and drying, if another release substrate is attached as necessary, the adhesive layer itself can also be transferred to another substrate.

＜Release base material＞ The release base material is not particularly limited. For example, it can be exemplified by setting up coating layers of clay, polyethylene, polypropylene and other fillers on both sides of paper such as high-quality paper, kraft paper, paper roll, cellophane, etc., and then on each coating layer It is obtained by coating silicone, fluorine, and alkyd release agents on top. In addition, various olefin films such as polyethylene, polypropylene, ethylene-α-olefin copolymers, and propylene-α-olefin copolymers may be used alone, and films such as polyethylene terephthalate may be coated with the above-mentioned release Those who get the agent. Considering the release force of the release base material and the adhesive layer, and the adverse effects of polysiloxane on the electrical properties, etc., it is advisable to carry out polypropylene filling treatment on both sides of the high-quality paper and use an alkyd-based release agent on it. Those obtained from a mold agent, or those obtained by using an alkyd-based mold release agent on polyethylene terephthalate.

In addition, the method of applying the adhesive composition to the substrate in the present invention is not particularly limited, and examples include a comma coater, a reverse roll coater, and the like. Or, if necessary, an adhesive layer can be provided directly or by a transfer method on the rolled copper foil or the polyimide film that is the constituent material of the printed wiring board. The thickness of the adhesive layer after drying can be appropriately changed as needed, and should be in the range of 5~200μm. When the thickness of the bonding film is 5μm or more, sufficient bonding strength can be obtained. In addition, by being 200 μm or less, it is easy to control the amount of residual solvent in the drying step, and it is difficult to generate swelling during the pressing of the printed wiring board. The drying conditions are not particularly limited, and the residual solvent rate after drying is preferably 1% by mass or less. By being 1% by mass or less, foaming of residual solvent can be suppressed when the printed wiring board is pressed, and swelling is not easily generated.

＜Printed wiring board＞ The printed wiring board in the present invention contains a laminate composed of a metal foil forming a conductor circuit and a resin substrate as a constituent element. The printed wiring board can be manufactured by a conventionally known method such as a subtraction method using a metal-clad laminate, for example. If necessary, use cover film, screen printing ink, etc. to partially or completely cover the conductor circuit formed by the metal foil, which is collectively referred to as the so-called flexible circuit board (FPC), flat cable, and tape-to-tape automatic bonding (TAB). Circuit boards, etc.

The printed wiring board of the present invention can be made into any laminated structure that can be used as a printed wiring board. For example, it can be made into a printed wiring board composed of four layers of a base film layer, a metal foil layer, an adhesive layer, and a cover film layer. In addition, for example, a printed wiring board composed of five layers of a base film layer, an adhesive layer, a metal foil layer, an adhesive layer, and a cover film layer can be produced.

Furthermore, if necessary, it can also be made into the structure which laminated|stacked 2 or 3 or more of the said printed wiring boards.

The adhesive composition of the present invention can be ideally used in each adhesive layer of a printed wiring board. In particular, when the adhesive composition of the present invention is used as an adhesive, it not only has high adhesiveness with conventional polyimide, polyester film, and copper foil constituting printed wiring boards, but also has low adhesion to LCP, etc. The polar resin substrate has high adhesion, can obtain solder reflow resistance, and the adhesive layer itself has excellent low dielectric properties. Therefore, it is suitable as an adhesive composition used for cover film, laminate, copper foil with resin, and bonding sheet.

Regarding the substrate film in the printed wiring board of the present invention, any resin film that has been used as a substrate of a printed wiring board from the past can be used. The resin of the substrate film can be exemplified: polyester resin, polyamide resin, polyimide resin, polyimide resin, liquid crystal polymer, polyphenylene sulfide, parapolystyrene, polyolefin resin , And fluorine-based resins, etc. In particular, it has excellent adhesion to low-polarity substrates such as liquid crystal polymers, polyphenylene sulfide, para-polystyrene, and polyolefin resins.

＜Cover film＞ As the cover film, any insulating film conventionally known as an insulating film for printed wiring boards can be used. For example, polyimide, polyester, polyphenylene sulfide, polyether ether, polyether ether ketone, polyaramide, polycarbonate, polyarylate, polyamide imide, liquid crystal polymer, Films made of various polymers such as parallel polystyrene and polyolefin resins. More preferably, it is a polyimide film or a liquid crystal polymer film.

The printed wiring board of the present invention can be manufactured using any conventionally known process in addition to the materials of the above-mentioned layers.

A preferred embodiment is: a semi-finished product (hereinafter referred to as "covering film-side semi-finished product") obtained by manufacturing the adhesive layer on the cover film laminated layer. On the other hand, a semi-finished product (hereinafter referred to as "two-layer semi-finished product on the base film side") produced by laminating a metal foil layer on a base film and forming a desired circuit pattern, or an adhesive layer laminated on the base film And a semi-finished product (hereinafter referred to as "3-layer semi-finished product on the base film side") by laminating a metal foil layer on it and forming the desired circuit pattern (hereinafter, the two-layer semi-finished product on the base film side and the base film side The three-layer semi-finished products are collectively referred to as the "substrate film-side semi-finished products"). By bonding the semi-finished product on the cover film side and the semi-finished product on the base film side obtained in this way, a 4-layer or 5-layer printed wiring board can be obtained.

The semi-finished product on the base film side, for example, may include (A) the step of coating the aforementioned metal foil with a resin solution that will form the base film and preliminarily drying the coating film, and (B) the metal foil obtained in (A) It is obtained by the manufacturing method of heat-treating and drying the laminate with the preliminarily dried coating film (hereinafter referred to as "heat-treatment-desolventizing step").

Conventionally known methods can be used for circuit formation on the metal foil layer. Additive or subtractive methods can be used. It should be the subtraction method.

The obtained semi-finished product on the side of the substrate film can be directly used for lamination with the semi-finished product on the side of the cover film, and it can also be applied to the semi-finished product on the cover film side after lamination and storage.

The cover film side semi-finished product can be manufactured by applying an adhesive to the cover film, for example. If necessary, the cross-linking reaction of the coated adhesive can be carried out. In a preferred embodiment, the adhesive layer is semi-hardened.

The obtained cover film side semi-finished product can be directly used for bonding with the base film side semi-finished product, and the release film can also be bonded and stored, and then used for bonding with the base film side semi-finished product.

The semi-finished product on the base film side and the semi-finished product on the cover film side are stored in the form of a reel, for example, and then bonded together to produce a printed wiring board. As for the bonding method, any method can be used, and for example, pressing or a roll can be used for bonding. In addition, it is also possible to bond the two while heating by using a method such as heating and pressing or a heating roller device.

The semi-finished product on the side of the reinforcing material, for example, in the case of using a soft and windable reinforcing material such as polyimide film, it is ideal to coat the reinforcing material with an adhesive. In addition, for example, in the case of using metal plates such as SUS, aluminum, or hardened glass fibers with epoxy resin, which are hard and unable to be wound, the adhesives that have been pre-coated on the release base material are used. It is ideal to manufacture the agent by transfer coating. In addition, the cross-linking reaction of the coated adhesive can be performed as needed. In a preferred embodiment, the adhesive layer is semi-hardened.

The obtained semi-finished product on the side of the reinforcing material can be directly used for bonding with the back of the printed wiring board, and the release film can also be bonded and stored before being used for bonding with the semi-finished product on the side of the substrate film.

The semi-finished product on the base film side, the semi-finished product on the cover film side, and the semi-finished product on the reinforcing material side are all laminates for printed wiring boards in the present invention. [Example]

Hereinafter, the present invention will be specifically explained with examples. In addition, in the present examples and comparative examples, parts by mass are simply expressed in parts.

(Physical property evaluation method) For the measurement of the composition of the polyester, a 400 MHz ¹ H-nuclear magnetic resonance spectrometer (hereinafter, sometimes abbreviated as NMR) was used to quantify the molar ratio of the polycarboxylic acid component and the polyol component constituting the polyester. The solvent is deuterated chloroform. In addition, when the acid value of the polyester is increased by the acid post-addition, the total of acid components other than the acid component used for the acid post-addition is 100 mol%, and the molar ratio of each component is calculated.

Determination of glass transition temperature The measurement was performed using a differential scanning calorimeter (SII company, DSC-200). Put 5 mg of the sample (polyester) into an aluminum gland type container and seal it, and use liquid nitrogen to cool to -50°C. Then, the temperature is raised to 150°C at a heating rate of 20°C/min. In the endothermic curve obtained during the heating process, the extension of the baseline before the endothermic peak (below the glass transition temperature) and the tangent to the endothermic peak (show The temperature at the point of intersection between the rising part of the peak and the tangent of the maximum slope between the apex of the peak is taken as the glass transition temperature (Tg, unit: °C).

Determination of number average molecular weight A sample of polyester is dissolved and/or diluted with tetrahydrofuran so that the resin concentration becomes approximately 0.5% by weight, and filtered with a membrane filter made of polytetrafluoroethylene with a pore size of 0.5 μm as a sample for measurement. The molecular weight was measured by gel permeation chromatography (GPC) using tetrahydrofuran as a mobile phase and a differential refractometer as a detector. The flow rate is set to 1 mL/min, and the column temperature is set to 30°C. The column system uses Showa Denko KF-802, 804L, and 806L. The molecular weight standard uses monodisperse polystyrene.

Determination of acid value Dissolve 0.2 g of a polyester sample in 40 ml of chloroform, and titrate with a 0.01N potassium hydroxide ethanol solution to obtain ^{the equivalent weight per 10 6} g of polyester (eq/10 ⁶ g). The indicator system uses phenolphthalein.

The following shows a synthesis example of the polyester used in the present invention.

Synthesis example of polyester (a1) In a reaction vessel equipped with a stirrer, a condenser, and a thermometer, 326 parts of dimethyl 2,6-naphthalenedicarboxylate and 1520 parts of dimer diol (Croda Corporation, Pripol 2033) were added, which was 0.03 moles relative to the total acid content. Tetrabutyl orthotitanate, which is used as a catalyst, was heated from 160°C to 220°C in 4 hours, and the esterification reaction was carried out while going through the dehydration step. Then, in the polycondensation reaction step, the pressure in the system was reduced to 5 mmHg over 20 minutes, and the temperature was further increased to 250°C. Then, after the pressure was reduced to 0.3 mmHg or less and the polycondensation reaction was performed for 60 minutes, it was taken out. As a result of analyzing the composition of the obtained polyester (a1) by NMR, the molar ratio was 2,6-naphthalenedicarboxylic acid/dimer diol=100/100 [molar ratio]. In addition, the glass transition temperature is -17°C. The results are shown in Table 1.

Synthesis example of polyester (a2)~(a15) According to the production example of polyester (a1), the type and blending ratio of raw materials were changed to synthesize polyester (a2) to (a15). In addition, the polyester (a9) was added to 8 parts by mass of trimellitic anhydride after the completion of the polymerization reaction, and reacted at 230°C for 30 minutes to perform acid post-addition. The results are shown in Table 1. In addition, PTMG1000 is polytetramethylene ether glycol (average molecular weight 1000).

[Table 1]

(Evaluation of adhesive composition) Relative permittivity (ε _c ) and dielectric loss tangent (tanδ) The adhesive composition is applied to a Teflon with a thickness of 100 μm so that the thickness after drying becomes 25 μm (Registered trademark) sheet, dried at 130°C for 3 minutes. Then, heat treatment was performed at 170°C for 3 hours to harden, and then the Teflon (registered trademark) sheet was peeled off to obtain an adhesive resin sheet for testing. Then, the obtained test adhesive resin sheet was cut into 8 cm×3 mm strip-shaped samples to obtain test samples. The relative permittivity (ε _c ) and the dielectric loss tangent (tanδ) were measured using a Network Analyzer (manufactured by Anritsu Co., Ltd.) by the cavity resonator perturbation method at a temperature of 23° C. and a frequency of 10 GHz. <Evaluation criteria for relative permittivity> ◎: 2.3 or less ○: more than 2.3 and less than 3.0 ×: more than 3.0 <evaluation criteria for dielectric loss tangent> ◎: 0.005 or less ○: more than 0.005 and less than 0.008 ×: more than 0.008

Solvent solubility Solvent solubility is evaluated by using polyester toluene varnish before adding hardener. The solubility when the polyester is dissolved in toluene so that the solid content concentration becomes 60% by mass, 50% by mass, or 30% by mass while stirring at 80°C for 6 hours was evaluated based on the following criteria. <Evaluation criteria for solvent solubility> ◎: When the solid content concentration is 60% by mass, it dissolves completely without residue ○: When the solid content concentration is 50% by mass, it dissolves completely without residue △: When the solid content concentration is 30% by mass, it dissolves completely without residue ×: When the solid content concentration is 30% by mass, the resin is not completely dissolved and remains

Peel strength (adhesion) The adhesive composition was applied to a polyimide film (manufactured by Kaneka Co., Ltd., APICAL (registered trademark)) with a thickness of 12.5 μm so that the thickness after drying became 25 μm, and dried at 130°C for 3 minutes . The adhesive film (B-stage product) obtained in this way was bonded to a rolled copper foil (manufactured by JX Metal Co., Ltd., BHY series) with a thickness of 18 μm. The bonding system is such that the glossy surface of the rolled copper foil is in contact with the adhesive layer, and it is bonded by pressing at 160° C. under a pressure of 2 MPa for 30 seconds. Then, it was heat-treated at 170° C. for 3 hours to be hardened, and a sample for peel strength evaluation was obtained. Regarding the peel strength, the film was stretched at 25°C, a 90° peel test was performed at a stretching speed of 50 mm/min, and the peel strength was measured. This test indicates the bonding strength at room temperature. <Evaluation criteria> ◎: 1.0N/mm or more ○: 0.8N/mm or more and less than 1.0N/mm △: 0.5N/mm or more and less than 0.8N/mm ×: less than 0.5N/mm

Heat resistance The adhesive composition was applied to a Teflon (registered trademark) sheet with a thickness of 100 μm so that the thickness after drying became 25 μm, and dried at 130° C. for 3 minutes. Then, after heat treatment was performed at 170°C for 3 hours to harden, the Teflon (registered trademark) sheet was peeled off to obtain an adhesive resin sheet for testing. The measurement was performed using a differential thermal-thermogravimetry simultaneous measuring device (Shimadzu Corporation, DTG-60). Put 50mg of the adhesive resin sheet into a platinum tank, and heat up to 1000°C at a temperature rise rate of 5°C/min under a nitrogen atmosphere with a flow rate of 20ml/min. The decomposition at high temperature is carried out, and the temperature when the weight becomes 95% of the initial value is the 5% weight reduction temperature, and this is used as an index of heat resistance. <Evaluation criteria for heat resistance> ○: 5% weight reduction temperature is 300°C or higher ×: 5% weight loss temperature is less than 300℃

Below, the manufacturing example of the adhesive composition which becomes an Example of this invention, and the adhesive composition which becomes a comparative example is shown.

The following hardeners are used. (b1): Polyisocyanate (SUMIDUR N3300 (manufactured by Sumika Covestro Urethane)) (b2): Epoxy resin (EPICLON HP-7200H (manufactured by DIC Corporation))

(Example 1) The polyester (a1) obtained in the aforementioned synthesis example was dissolved in toluene to prepare a toluene varnish with a solid content of 30% by mass. The hardener (b1) was blended with this toluene varnish so that it may become 2 parts with respect to 100 parts of polyester (a1), and the adhesive composition (A1) was obtained. For the obtained adhesive composition (A1), evaluations of solvent solubility, relative permittivity, dielectric loss tangent, heat resistance, and peel strength were performed. The results are shown in Table 2.

(Examples 2 to 12, Comparative Examples 1 to 5) Except changing the type of polyester and the type and blending amount of the curing agent as shown in Table 2, the adhesive compositions (A2) to (A17) were produced in the same manner as in Example 1, and each evaluation was performed. . The results are shown in Table 2.

[產業利用性][Table 2]

[Industrial Utilization]

The adhesive composition of the present invention has excellent solvent solubility, low relative permittivity and low dielectric loss tangent, and is useful as an adhesive for FPC in the high frequency region.

Claims (6)

An adhesive composition containing polyester and hardener, the polyester contains polycarboxylic acid components and polyol components as structural units, and when the polycarboxylic acid component is 100 mol%, it contains more than 50 mol% The naphthalene dicarboxylic acid component contains at least one of a dimer diol component and a tricyclodecane dimethanol component as a polyol component. The adhesive composition of claim 1, wherein the glass transition temperature of the polyester is -30°C or higher. For example, the adhesive composition of claim 1 or 2 has a relative dielectric constant (εc) of 3.0 or less at 10 GHz, and a dielectric loss tangent (tanδ) of 0.008 or less. An adhesive sheet having a layer formed of the adhesive composition according to any one of claims 1 to 3. A laminate having a layer formed of the adhesive composition according to any one of claims 1 to 3. A printed wiring board containing a laminate as in Claim 5 as a constituent element.