TW202130770A - Adhesive composition, adhesive sheet, laminate, and printed wiring board - Google Patents

Abstract

To provide an adhesive composition which has a high adhesion to a metal substrate and a resin substrate such as a liquid crystal polymer or syndiotactic polystyrene as well as to a conventional polyimide or polyester film, and also has excellent low dielectric characteristics and pot life, and from which high solder heat resistance can be achieved. This adhesive composition contains (a) an acid-modified polyolefin, (b) a phenol resin having a polycyclic structure, and (c) an epoxy resin.

Description

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

The present invention relates to adhesive compositions. More specifically, it relates to the adhesive composition used for bonding 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 containing the adhesive composition.

Flexible printed wiring boards (FPC) have excellent flexibility and can correspond to the multi-function and miniaturization of personal computers (PC), smart phones, etc., so they are often used to incorporate electronic circuit boards into small and complex interiors. . In recent years, the miniaturization, weight reduction, high density, and high output of electronic devices have progressed, and due to their popularity, the requirements for the performance of wiring boards (electronic circuit boards) have increased. Especially with the increase of the transmission signal speed in FPC, the high frequency of the signal is progressing. Along with this, as far as FPC is concerned, the requirements for low dielectric properties (low dielectric constant, low dielectric loss tangent) in the high-frequency region have increased. In addition, for the substrate used in FPC, not only the conventional polyimide (PI) and polyethylene terephthalate (PET) have been proposed, but also liquid crystal polymers with low dielectric properties have been proposed ( Base film such as LCP), Parallel Polystyrene (SPS), etc. In order to achieve such low dielectric properties, there have been methods to reduce the dielectric loss of the FPC substrate and adhesive. As for the adhesive, development of a combination of polyolefin and epoxide (Patent Document 1) or a combination of elastomer and epoxide (Patent Document 2) is underway. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] WO2016/047289 Publication [Patent Document 2] WO2014/147903 Publication

[The problem to be solved by the invention]

However, in Patent Document 1, the heat resistance of the adhesive used in the reinforcing plate and between the layers is hardly said to be excellent. In addition, Patent Document 2 has insufficient storage stability after blending, which is important at the time of use.

In order to solve the above-mentioned problems, the present invention has conducted in-depth research and found that the adhesive composition with a specific composition has not only the conventional polyimide film, but also a resin substrate such as liquid crystal polymer or parapolystyrene. And high adhesion to metal substrates such as copper foil, in addition, low dielectric properties (electric properties), solder heat resistance, and pot life properties after blending are excellent, and the present invention is completed.

That is, the object of the present invention is to provide good adhesion not only to polyimide, but also to various resin substrates such as liquid crystal polymers or parapolystyrene and metal substrates, and low dielectric properties ( An adhesive composition with excellent electrical properties), solder heat resistance, and pot life properties. [Means to solve the problem]

An adhesive composition containing: Acid-modified polyolefin (a), Phenolic resin (b) with polycyclic structure, and Epoxy resin (c).

The phenolic resin (b) having a polycyclic structure is preferably a phenolic resin having a tricyclodecane skeleton, and preferably has a carbonate skeleton. The acid value of the acid-modified polyolefin (a) is preferably 5-40 mgKOH/g.

It is more suitable to contain polycarbodiimide (d). In addition, relative to 100 parts by mass of acid-modified polyolefin (a), it is preferable to contain 0.05 to 120 parts by mass of phenolic resin (b) having a polycyclic structure, 0.1 to 60 parts by mass of epoxy resin (c), and 0.1 ~30 parts by mass of polycarbodiimide (d).

For the aforementioned adhesive composition, the relative dielectric constant (ε _c ) at 1 GHz is preferably 3.0 or less, and the dielectric loss tangent (tanδ) is preferably 0.02 or less.

An adhesive sheet or laminate containing the aforementioned adhesive composition. A printed wiring board containing the aforementioned laminate as a constituent element. [Effects of Invention]

The adhesive composition of the present invention has good adhesion not only to polyimide, but also to various resin substrates such as liquid crystal polymer or parapolystyrene and metal substrates, and has low dielectric properties ( Electrical characteristics), solder heat resistance, excellent pot life characteristics.

＜Acid modified polyolefin (a)＞ The acid-modified polyolefin (a) used in the present invention (hereinafter also referred to as (a) component) is not limited, and it is preferable to graft at least one of α, β-unsaturated carboxylic acid and its anhydride on Derived from polyolefin resin. Polyolefin resin refers to homopolymers of olefin monomers exemplified by ethylene, propylene, butene, butadiene, isoprene, etc., or copolymers with other monomers, and hydrogenated products of the resulting polymers, Halides and other polymers with a hydrocarbon skeleton as the main body. That is, the acid-modified polyolefin is preferably obtained by grafting at least one of α, β-unsaturated carboxylic acid and its anhydride to at least one of polyethylene, polypropylene, and propylene-α-olefin copolymer. And the winner.

The propylene-α-olefin copolymer is formed by copolymerizing α-olefin with propylene as the main body. For the α-olefin, for example, one or more of ethylene, 1-butene, 1-heptene, 1-octene, 4-methyl-1-pentene, vinyl acetate, and the like can be used. Among these α-olefins, ethylene and 1-butene are preferable. The ratio of the propylene component to the α-olefin component of the propylene-α-olefin copolymer is not limited, but the propylene component is preferably 50 mol% or more, more preferably 70 mol% or more.

Examples of at least one of α,β-unsaturated carboxylic acids and their anhydrides include maleic acid, itaconic acid, citraconic acid, and their anhydrides. Among them, acid anhydride is preferable, and maleic anhydride is more preferable. Specifically, examples include: maleic anhydride-modified polypropylene, maleic anhydride-modified propylene-ethylene copolymer, maleic anhydride-modified propylene-butene copolymer, maleic anhydride-modified propylene-ethylene-butene copolymer These acid-modified polyolefins can be used singly or in combination of two or more.

The acid value of the acid-modified polyolefin (a), considering the heat resistance and adhesion to the resin substrate and metal substrate, the lower limit is preferably 5 mgKOH/g or more, more preferably 6 mgKOH/g or more, and 7 mgKOH/ Above g is even better. By setting it to be higher than the aforementioned lower limit, the compatibility with the epoxy resin (c) can be improved and excellent bonding strength can be exhibited. Furthermore, the crosslink density is high and the solder heat resistance becomes good. The upper limit is preferably 40 mgKOH/g or less, more preferably 30 mgKOH/g or less, and even more preferably 20 mgKOH/g or less. By setting it below the aforementioned upper limit, the adhesiveness becomes better. Moreover, the viscosity and stability of the solution will become better, and it can exhibit excellent pot life characteristics. In addition, manufacturing efficiency will also improve.

The number average molecular weight (Mn) of the acid-modified polyolefin (a) is preferably in the range of 10,000 to 50,000. The range of 15,000 to 45,000 is more preferable, the range of 20,000 to 40,000 is even more preferable, and the range of 22,000 to 38,000 is particularly preferable. By setting it to be higher than the aforementioned lower limit, the cohesive force can be improved and excellent adhesiveness can be exhibited. In addition, by setting it to the upper limit or less, the fluidity is excellent and the operability is good.

The acid-modified polyolefin (a) is preferably a crystalline acid-modified polyolefin. The crystallinity referred to in the present invention refers to the use of a differential scanning calorimeter (DSC), the temperature is raised from -100°C to 250°C at a condition of 20°C/min, and a clear melting peak is exhibited during the heating process.

The melting point (Tm) of the acid-modified polyolefin (a) is preferably in the range of 50°C to 120°C. The range of 60℃~100℃ is more preferable, and the range of 70℃~90℃ is the best. By setting it to the aforementioned lower limit or more, the cohesive force derived from crystals can be improved, and excellent adhesiveness and solder heat resistance can be exhibited. In addition, by setting it to the upper limit or less, the solution has excellent stability and fluidity, and the workability at the time of bonding is good.

The heat of fusion (ΔH) of the acid-modified polyolefin (a) is preferably in the range of 5J/g~60J/g. The range of 10J/g~50J/g is more preferable, and the range of 20J/g~40J/g is the best. By setting it to the aforementioned lower limit or more, the cohesive force derived from crystals can be improved, and excellent adhesiveness and solder heat resistance can be exhibited. In addition, by setting it to the upper limit or less, the solution has excellent stability and fluidity, and the workability at the time of bonding is good.

The production method of acid-modified polyolefin (a) is not particularly limited. Examples include: radical grafting reaction (that is, a radical species is generated on the polymer of the main chain, and the radical species is used as the polymerization start Point to graft polymerization reaction of unsaturated carboxylic acid and acid anhydride) and so on.

The radical generator is not particularly limited, but organic peroxides are preferably used. Organic peroxides are not particularly limited. Examples include: di(tertiary butyl) peroxyphthalate, tertiary butyl hydroperoxide, dicumyl peroxide, benzyl peroxide, and benzoic acid peroxide. Tertiary butyl ester, tertiary butyl peroxide-2-ethylhexanoate, tertiary butyl peroxide trimethyl acetate, methyl ethyl ketone peroxide, di(tertiary butyl) peroxide, lauryl peroxide, etc. Peroxides; azo nitriles such as azobisisobutyronitrile, azobisisopropionitrile, etc.

＜Phenolic resin with polycyclic structure (b)＞ The phenol resin (b) having a polycyclic structure used in the present invention (hereinafter also referred to as (b) component) is not limited as long as it is a phenol resin having one or more polycyclic structures in one molecule. Polycyclic structure refers to a structure formed by bonding multiple ring structures mainly composed of carbon. Examples include aromatic skeletons such as naphthalene, anthracene, dihydroindene, and tetrahydronaphthalene; decalin, norbornane, Tricyclodecane and the like have a structure with an alicyclic skeleton. By having a polycyclic structure, the free volume of the resin will increase and it will exhibit low dielectric properties. And it will exert heat resistance. The number of polycyclic structures contained in one molecule is preferably 2 or more, and more preferably 3 or more. Moreover, it is preferably 10 or less, more preferably 8 or less, and even more preferably 5 or less. By setting it within the aforementioned range, excellent dielectric properties can be exhibited. The polycyclic structure is not particularly limited. It is preferably an alicyclic skeleton with 4 to 30 carbons, preferably an alicyclic skeleton with 5 to 25 carbons, and even more preferably an alicyclic skeleton with 8 to 20 carbons, which is the carbon number The alicyclic skeleton of 10~15 is particularly good. Specific examples of the polycyclic structure include, for example, bicyclobutane, dicyclopentane, bicyclohexane, bicycloheptane (norbornane), bicyclooctane, bicyclononane, and bicyclodecane, which may optionally have substituents. Bicyclic alicyclic structures; tricyclic alicyclic structures such as tricyclooctane, tricyclononane, tricyclodecane, tricycloundecane, tricyclododecane, etc. may also be optionally substituted; It can also optionally have substituents such as tetracyclodecane, tetracycloundecane, tetracyclododecane, and other alicyclic structures of four or more ring systems; it can also optionally have substituents of naphthalene, anthracene, indene, Aromatic structures such as tetralin. In addition, the aforementioned alicyclic structure may have an unsaturated bond, and examples thereof include bicycloheptene, bicyclohexene, bicycloheptene, bicyclooctene, bicyclononene, and bicyclodecene which may optionally have substituents. These polycyclic structures may have 1 type in 1 molecule of phenol resin, and may have 2 or more types. The aforementioned substituents are not particularly limited, and examples include alkyl groups such as methyl, ethyl, and propyl; alkoxy groups such as methoxy and ethoxy; thioalkyl groups such as thiomethoxy and thioethoxy. Oxy; hydroxyl, amino, etc.

Among the aforementioned polycyclic structures, tricyclic alicyclic structures such as tricyclooctane, tricyclononane, tricyclodecane, tricycloundecane, tricyclododecane, etc., which may also have substituents, are preferred. Tricyclodecane, which may also have a substituent, is more preferable. Among them, tricyclo[5.2.1.0 ^2,6 ]decane, tricyclo[6.1.1.0 ^2,6 ]decane, tricyclo[6.1.1.0 ^2,7 ]decane, tricyclo[6.1.1.0 2,7]decane, The ring [3.3.1.1 ^3,7 ] decane (adamantane) is particularly preferably a tricyclic [5.2.1.0 ^2,6 ] decane which may have a substituent. Specifically, 3,4-dimethylene tricyclo[5.2.1.0 ^2,6 ] decane, 3,5-dimethylene tricyclo[5.2.1.0 ^2,6 ] decane, 3 ,8-Dimethylene tricyclo[5.2.1.0 ^2,6 ]decane, 3,9-Dimethylene tricyclo[5.2.1.0 ^2,6 ]decane, 8,9-Dimethylene tricyclo[5.2.1.0 2,6 ]decane Cyclo[5.2.1.0 ^2,6 ]decane, among them, 3,5-dimethylene tricyclo[5.2.1.0 ^2,6 ]decane is preferred.

The phenolic resin (b) having a polycyclic structure preferably has a carbonate skeleton. By having a carbonate skeleton, the adhesiveness and electrical properties can be maintained, and at the same time, flexibility can be imparted to the adhesive composition. The carbonate skeleton contained in the phenol resin (b) having a polycyclic structure is preferably 2 or more per molecule, more preferably 3 or more, and more preferably 4 or more. Moreover, it is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less.

通式(1)中，m、n宜分別獨立地為1以上且10以下之整數，為8以下更佳，為5以下再更佳，為2以下特佳。The phenol resin (b) having a polycyclic structure preferably has a structure represented by the general formula (1). [化1]

In the general formula (1), m and n are each independently an integer of 1 or more and 10 or less, more preferably 8 or less, more preferably 5 or less, and particularly preferably 2 or less.

通式(2)中，m、n和前述同義。p宜為1以上且10以下之整數，為2以上更佳，為3以上再更佳，為4以上特佳。又，宜為8以下，為5以下再更佳。R₁ 、R₂ 分別獨立地為也可具有取代基之芳香族烴，取代基宜為也可更具有取代基之脂肪族烴、也可更具有取代基之脂環族烴、或也可更具有取代基之芳香族烴。Moreover, it is more preferable that the phenol resin (b) having a polycyclic structure has the general formula (2). [化2]

In the general formula (2), m and n are synonymous with the foregoing. p is preferably an integer of 1 or more and 10 or less, more preferably 2 or more, more preferably 3 or more, and particularly preferably 4 or more. Moreover, it is preferably 8 or less, and more preferably 5 or less. R ₁ and R ₂ are each independently an aromatic hydrocarbon that may also have a substituent, and the substituent is preferably an aliphatic hydrocarbon that may have more substituents, an alicyclic hydrocarbon that may have more substituents, or more Aromatic hydrocarbons with substituents.

[化4]

式(11)、式(12)中，R₃ 、R₄ 宜分別獨立地為碳數1~10之烷基、碳數1~10之烷氧基、碳數2~10之烯基、或也可具有取代基之苯基。為碳數1~5之烷基或碳數1~5之烯基更佳，為碳數1~3之烷基或碳數2~3之烯基再更佳。具體而言，宜為甲基、乙基、正丙基、異丙基、丙烯基。x、y分別獨立地為0~4之整數，宜為0~3之整數，為0或1更佳，為1特佳。Z₁ 宜為0~5之整數，為1~3之整數更佳，為1或2再更佳，為1特佳。Z₂ 宜為0~5之整數，為1~3之整數更佳，為1或2再更佳，為1特佳。羥基或醚基對於苄基而言，可為鄰位、間位、對位中之任一者，但宜為對位。*表示和通式(2)之氧原子的原子鍵。Preferably, the aforementioned R ₁ and R ₂ are independently those having the structure of formula (11) or formula (12). [化3]

[化4]

In formula (11) and formula (12), R ₃ and R ₄ are each independently an alkyl group with 1 to 10 carbons, an alkoxy group with 1 to 10 carbons, an alkenyl group with 2 to 10 carbons, or It may also have a substituted phenyl group. It is more preferably an alkyl group with 1 to 5 carbons or an alkenyl group with 1 to 5 carbons, and more preferably an alkyl group with 1 to 3 carbons or an alkenyl group with 2 to 3 carbons. Specifically, it is preferably methyl, ethyl, n-propyl, isopropyl, and propenyl. x and y are each independently an integer from 0 to 4, preferably an integer from 0 to 3, more preferably 0 or 1, and particularly preferably 1. Z _{1 is} preferably an integer from 0 to 5, more preferably an integer from 1 to 3, more preferably 1 or 2, and particularly preferably 1. Z _{2 is} preferably an integer from 0 to 5, more preferably an integer from 1 to 3, more preferably 1 or 2, and particularly preferably 1. For the benzyl group, the hydroxyl group or the ether group may be any of ortho, meta, and para positions, but is preferably para. * Represents the atomic bond with the oxygen atom of the general formula (2).

(b) The number average molecular weight of the component is preferably 5000 or less, more preferably 4000 or less, and even more preferably 3500 or less. In addition, the number average molecular weight of the component (b) is preferably 500 or more, and more preferably 700 or more. By setting the number average molecular weight of the component (b) to be equal to or higher than the lower limit, the adhesive layer obtained can have good flexibility. On the other hand, by setting the number average molecular weight of the component (b) to the upper limit or less, the solubility in organic solvents can be improved.

The content of the component (b) relative to 100 parts by mass of the component (a) is preferably 0.05 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 5 parts by mass or more. By setting it above the aforementioned lower limit value, excellent solder heat resistance can be exhibited. Moreover, it is preferably 120 parts by mass or less, more preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and particularly preferably 80 parts by mass or less. By setting it below the aforementioned upper limit, excellent adhesion and solder heat resistance can be exhibited.

＜Epoxy resin (c)＞ The epoxy resin (c) used in the present invention (hereinafter also referred to as (c) component) is not particularly limited as long as it has an epoxy group in the molecule, and it is preferably one having two or more epoxy groups in the molecule. Specifically, it 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 ring Oxygen resin, dicyclopentadiene epoxy resin, tetraglycidyl diamino diphenyl methane, triglycidyl p-amino phenol, tetraglycidyl diamino methyl cyclohexanone, N ,N,N',N'-tetraepoxypropyl m-xylene diamine and epoxy-modified polybutadiene at least one of the group, but it is not particularly limited. It is preferably biphenyl type epoxy resin, novolac type epoxy resin, dicyclopentadiene type epoxy resin, triglycidyl p-aminophenol or epoxy modified polybutadiene. More preferably, it is dicyclopentadiene type epoxy resin, novolac type epoxy resin or triglycidyl p-aminophenol.

In the adhesive composition of the present invention, the content of the epoxy resin (c) relative to 100 parts by mass of the acid-modified polyolefin (a) is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and 1 mass Part or more is more preferable, and 2 parts by mass or more is particularly preferable. By setting it 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, more preferably 40 parts by mass or less, and particularly preferably 35 parts by mass or less. By setting it below the aforementioned upper limit value, pot life characteristics and low dielectric characteristics are good. That is, by setting it within the above range, an adhesive composition having excellent low dielectric properties in addition to adhesiveness, solder heat resistance, and pot life characteristics can be obtained.

＜Polycarbodiimide (d)＞ The polycarbodiimide (d) (hereinafter also referred to as (d) component) used in the present invention is not particularly limited as long as it has a carbodiimide group in the molecule. Preferably, it is a polycarbodiimide having two or more carbodiimide groups in the molecule. By using polycarbodiimide, the carboxyl group and carbodiimide group of the acid-modified polyolefin (a) will react, which can increase the interaction between the adhesive composition and the substrate and improve the adhesion.

In the adhesive composition of the present invention, the content of polycarbodiimide (d) relative to 100 parts by mass of the acid-modified polyolefin (a) is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, 1 part by mass or more is more preferable, and 2 parts by mass or more is particularly preferable. By setting it above the aforementioned lower limit, interaction with the substrate will be exhibited, and the adhesion will become better. Moreover, it is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, more preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and particularly preferably 10 parts by mass or less. By setting it below the aforementioned upper limit value, excellent pot life characteristics and low dielectric characteristics can be exhibited. That is, by setting it within the above range, an adhesive composition having excellent low dielectric properties in addition to adhesiveness, solder heat resistance, and pot life characteristics can be obtained. In addition, the content of the polycarbodiimide (d) relative to the epoxy resin (c) is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more with respect to 100 parts by mass of the epoxy resin (c) , More preferably 15 parts by mass or more. Moreover, it is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less. By setting it within the above range, an adhesive composition with a good balance of solder heat resistance and low dielectric properties can be produced.

＜Adhesive composition＞ The adhesive composition of the present invention can display low-polarity resin substrates such as liquid crystal polymer (LCP) and parapolystyrene (SPS) by containing the three resins of the aforementioned (a) component ~ (c) component , Or excellent adhesion, pot life characteristics, electrical characteristics (low dielectric characteristics) and heat resistance of metal substrates. That is, the adhesive composition is applied to the substrate, and the cured adhesive coating (adhesive layer) can exhibit excellent low dielectric constant characteristics.

The adhesive composition of the present invention may further contain an organic solvent. If the organic solvent used in the present invention dissolves acid-modified polyolefin (a), phenol resin (b) having a polycyclic structure, epoxy resin (c), and polycarbodiimide (d), then There are no special restrictions. Specifically, for example, aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as hexane, heptane, octane, and decane; cyclohexane, cyclohexene, methylcyclohexane, Alicyclic hydrocarbons such as ethyl cyclohexane; halogenated hydrocarbons such as trichloroethylene, dichloroethylene, chlorobenzene, chloroform; methanol, ethanol, isopropanol, butanol, pentanol, hexanol, propanediol, phenol, etc. Alcohol solvents; ketone solvents such as acetone, methyl isobutyl ketone, methyl ethyl ketone, pentanone, hexanone, cyclohexanone, isophorone, acetophenone, etc.; methyl cellophane, ethyl cellophane, etc. Cellulose; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl propionate, butyl formate, etc.; ethylene glycol mono-n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono Glycol ether solvents such as 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, etc., they can Use 1 type or combine 2 or more types. 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 the acid-modified polyolefin (a), more preferably in the range of 200 to 900 parts by mass, and most preferably in the range of 300 to 800 parts by mass. By setting it to be higher than the aforementioned lower limit, the liquid state and pot life characteristics are good. In addition, it is advantageous in terms of manufacturing cost and shipping cost by setting it below the aforementioned upper limit value.

_{The relative dielectric constant (ε c} ) of the adhesive composition of the present invention at a frequency of 1 GHz is preferably 3.0 or less. It is more preferably 2.6 or less, and even more preferably 2.3 or less. The lower limit is not particularly limited, but it is 2.0 in practice. In addition, the relative permittivity (ε) in the entire frequency range from 1 GHz to 60 GHz is preferably 3.0 or less, more preferably 2.6 or less, and even more preferably 2.3 or less.

The dielectric loss tangent (tanδ) of the adhesive composition of the present invention at a frequency of 1 GHz is preferably 0.02 or less. It is more preferably 0.01 or less, and even more preferably 0.008 or less. The lower limit is not particularly limited, but it is 0.0001 in practice. In addition, the dielectric loss tangent (tan δ) in the entire frequency range of 1 GHz to 60 GHz is preferably 0.02 or less, more preferably 0.01 or less, and even more preferably 0.005 or less.

In the present invention, the relative dielectric constant (ε _c ) and the dielectric loss tangent (tan δ) can be measured as follows. That is, the adhesive composition is applied to the release substrate so that the thickness after drying becomes 25 μm, and it is dried at about 130° C. for about 3 minutes. Then, heat treatment is performed at about 140° C. for about 4 hours and hardened, and the hardened adhesive composition layer (adhesive layer) is peeled from the release film. _{The relative dielectric constant (ε c} ) and dielectric loss tangent (tanδ) of the adhesive composition layer at a frequency of 1 GHz after peeling were measured. _{Specifically, the relative permittivity (ε c} ) and the dielectric loss tangent (tanδ) can be calculated by using the resonant cavity perturbation method.

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 can 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 well-known phosphoric acid esters (such as trimethyl phosphate, triphenyl phosphate, tricresol phosphate, etc.), phosphates (such as aluminum hypophosphite, etc.), phosphazene, etc. can be used. Phosphorus flame retardant. These may 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, and more preferably in the range of 5 to 150 parts by mass, relative to 100 parts by mass of the total of components (a) to (d), 10 The range of ~100 parts by mass is the best. By setting it within the aforementioned range, adhesion, solder heat resistance, and electrical properties can be maintained, while flame retardancy can be exhibited.

＜Tackifier＞ The adhesive composition of the present invention can also be blended with a tackifier as needed. Examples of tackifiers include polyterpene resins, rosin-based resins, aliphatic petroleum resins, alicyclic petroleum resins, copolymerized petroleum resins, styrene resins, hydrogenated petroleum resins, etc., which can be used to improve bonding strength And use. These may be used alone or in any combination of two or more kinds. When a tackifier is contained, the content of the tackifier is preferably in the range of 1 to 200 parts by mass, and more preferably in the range of 5 to 150 parts by mass, with respect to 100 parts by mass of the total of components (a) to (d), and is 10~ The range of 100 parts by mass is the best. By setting it within the aforementioned range, the adhesiveness, solder heat resistance, and electrical properties can be maintained while exhibiting the effect of the tackifier.

＜Filling＞ The adhesive composition of the present invention can also be blended with fillers such as silica as needed. By blending silicon dioxide, it will improve the characteristics of heat resistance, so it is very ideal. Silicon dioxide is generally known as hydrophobic silicon dioxide and hydrophilic silicon dioxide. In terms of moisture absorption resistance, dimethyldichlorosilane, hexamethyldisilazane, octylsilane, etc. The hydrophobic silica after treatment is preferred. When silicon dioxide is blended, the blending amount is preferably 0.05-30 parts by mass relative to 100 parts by mass of the total of components (a) to (d). By setting it to above the aforementioned lower limit value, further heat resistance can be exhibited. In addition, by setting it below the above upper limit value, poor dispersion of silica or excessively high solution viscosity can be suppressed, and workability can be improved.

＜Silane Coupling Agent＞ The adhesive composition of the present invention can also be blended with a silane coupling agent as needed. By blending the silane coupling agent, the adhesion to metal or the characteristics of heat resistance will be improved, so it is very ideal. The silane coupling agent is not particularly limited, and examples thereof include those having unsaturated groups, those having glycidyl groups, and those having amine groups. Among them, considering the viewpoint of heat resistance, γ-glycidoxypropyltrimethoxysilane, or β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or β-(3 , 4-epoxycyclohexyl) ethyl triethoxy silane and other silane coupling agents with glycidyl groups are even more preferable. 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 components (a) to (d). By setting it within the aforementioned range, the solder heat resistance and adhesiveness can be improved.

＜Laminated body＞ The laminate system of the present invention is formed by laminating an adhesive composition on a substrate (substrate/adhesive layer of 2 laminates), or further laminated with a substrate (substrate/adhesive layer) A 3-layer laminate of agent layer/substrate). Here, the adhesive layer refers to a layer of the adhesive composition after the adhesive composition of the present invention is coated on a substrate and dried. By applying the adhesive composition of the present invention to various substrates according to a conventional method and drying, and further laminating other substrates, the laminate of the present invention can be obtained.

＜Substrate＞ The substrate in the present invention is not particularly limited as long as it can be coated with the adhesive composition of the present invention and dried to form an adhesive layer, and examples include resin substrates such as film-like resins, metal plates, or metal foils. And other metal substrates, paper, 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).

Any conventional conductive material that can be used for circuit substrates can be used for the metal substrate. Examples of materials include various metals such as SUS, copper, aluminum, iron, steel, zinc, and nickel, and metals treated with various alloys, platings, and other metals such as zinc or chromium compounds. It is preferably a metal foil, and more preferably a copper foil. The thickness of the metal foil is not particularly limited, and is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 10 μm or more. Moreover, it is preferably 50 μm or less, more preferably 30 μm or less, and even 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 when making the circuit may be reduced. Metal foil is usually provided in the form of a roll. The form of the metal foil used when manufacturing the printed wiring board of this invention is not specifically limited. When using the metal foil in the form of a strip, its length is not particularly limited. In addition, the width is not particularly limited, and it is preferably about 250 to 500 cm. The surface roughness of the substrate is not particularly limited, and is preferably 3 μm or less, more preferably 2 μm or less, and even more preferably 1.5 μm or less. In addition, it is practically preferably 0.3 μm or more, more preferably 0.5 μm or more, and even more preferably 0.7 μm or more. Moreover, it is preferably 3 μm or less, more preferably 2 μm or less, and even more preferably 1.5 μm or less.

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

Considering the adhesive force and durability of the adhesive composition, the base material is preferably polyester resin, polyamide resin, polyimide resin, polyimide imide resin, liquid crystal polymer, polyphenylene sulfide, 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 is obtained by laminating the aforementioned laminated body and the release substrate with an adhesive composition. 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 composition 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, after drying, if the release base material is attached to the adhesive layer, it can be wound without causing back printing to the base material. 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, if it is applied to a release substrate and dried, and then attached to another release substrate as needed, the adhesive layer itself can also be transferred to another substrate.

＜Release base material＞ The release substrate is not particularly limited. For example, a coating layer of clay, polyethylene, polypropylene and other fillers is provided on both sides of high-quality paper, kraft paper, paper roll, cellophane, etc., and then applied to each It is formed by coating silicone, fluorine, and alkyd release agents on the layer. In addition, various olefin films such as polyethylene, polypropylene, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, and the like; and coating the above-mentioned films on polyethylene terephthalate, etc. Those made of release agent. Considering the demolding force of the mold release substrate and the adhesive layer, and the adverse effects of polysiloxane on the electrical properties, etc., it is advisable to fill in polypropylene on both sides of high-quality paper and use alkyd on it. It is made of a mold release agent, or a polyethylene terephthalate is made of an alkyd mold release agent.

In addition, the method of applying the adhesive composition to the substrate in the present invention is not particularly limited. The method of applying the adhesive composition to the substrate is not particularly limited, and examples thereof include: coating, reverse roll coating, and the like. Or, according to needs, an adhesive layer can be directly provided on the rolled copper foil, which is a material constituting a printed wiring board, or on a polyimide film, or an adhesive layer can be provided by a transfer method. The thickness of the adhesive layer after drying is appropriately changed according to needs, and it is preferably in the range of 5~200μm. By setting the thickness of the bonding film to 5μm or more, sufficient bonding strength can be obtained. In addition, by setting it to 200 μm or less, the amount of residual solvent in the drying step can be easily controlled, and swelling is less likely to occur 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 setting it to 1% by mass or less, foaming of the residual solvent can be suppressed when the printed wiring board is pressed, and swelling is less likely to occur.

＜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 is manufactured by a conventional method such as a subtraction method using a metal-clad laminate, for example. According to the needs, the conductor circuit formed by the metal foil is partially or completely coated with a cover film, screen printing ink, etc., which is collectively referred to as a flexible circuit board (FPC), flat cable, and tape-type automatic bonding ( TAB) used 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.

In addition, it can also be made into a structure in which two or three or more of the above-mentioned printed wiring boards are laminated as required.

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 resistance to the conventional polyimide, polyester film, and copper foil constituting printed wiring boards, but also low-polarity resin substrates such as LCP. Adhesion and resistance to solder reflow can be obtained, and the adhesive layer itself has excellent low dielectric properties. Therefore, it is suitable as an adhesive composition for cover film, laminate, copper foil provided with resin, and adhesive sheet.

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 as the base film. 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 polymer, polyphenylene sulfide, para-polystyrene, and polyolefin resin.

＜Cover film＞ As the cover film, any insulating film conventionally used as an insulating film for printed wiring boards can be used. For example, polyimide, polyester, polyphenylene sulfide, polyether ether, polyether ether ketone, aromatic polyamide, polycarbonate, polyarylate, polyamide imide, liquid crystal polymer can be used , Parallel polystyrene, polyolefin resin and other polymers made of films. It is more preferably a polyimide film or a liquid crystal polymer film.

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

An ideal embodiment is to manufacture a semi-finished product in which an adhesive layer is laminated on the cover film layer (hereinafter referred to as "cover film-side semi-finished product"). In addition, a semi-finished product in which a metal foil is laminated on a base film layer and a desired circuit pattern is formed (hereinafter referred to as "a two-layer semi-finished product on the base film side") or an adhesive is laminated on the base film layer, and used A semi-finished product (hereinafter referred to as "3-layer semi-finished product on the base film side") on which a metal foil layer is laminated to form the desired circuit pattern (hereinafter referred to as the two-layer semi-finished product on the substrate film side and the 3-layer semi-finished product on the substrate film side are collectively referred to as "Substrate film side semi-finished products"). By laminating 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 substrate film side can be, for example, a step of applying (A) a resin solution that becomes a substrate film to the aforementioned metal foil and subjecting the coating film to initial drying, and (B) the metal foil obtained from (A) and The laminate of the initially dried coating film is obtained by a manufacturing method of heat treatment and drying steps (hereinafter referred to as "heat treatment-solvent removal step").

A conventional method can be used to form the circuit in the metal foil layer. Additive or subtractive methods can be used. It should be the subtraction method.

The obtained base film side semi-finished product can be directly used for bonding with the cover film side semi-finished product, or it can be pasted with a release film for storage, and then used for bonding with the cover film side semi-finished product.

The cover film side semi-finished product is manufactured by applying an adhesive to the cover film, for example. The cross-linking reaction in the coated adhesive can be implemented according to needs. In an ideal 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, or it can be pasted with a release film for storage, 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 respectively stored in the form of a roll, for example, and then laminated to manufacture a printed wiring board. Any method may be used for the bonding method, and for example, pressing or a roll may be used for bonding. In addition, it is also possible to bond the two while applying heating by a method such as heating and pressing or using a heating roller device.

The semi-finished product on the reinforcing material side, for example, in the case of a flexible and windable reinforcing material such as a polyimide film, is preferably manufactured by applying an adhesive to the reinforcing material. In addition, for example, in the case of SUS, aluminum and other metal plates, glass fibers hardened with epoxy resin, and other hard and non-windable reinforcing plates, it is preferable to transfer the coating to the reinforcement plate beforehand. Manufactured by the adhesive of the mold base material. In addition, the cross-linking reaction in the coated adhesive can be implemented as required. In an ideal embodiment, the adhesive layer is semi-hardened.

The obtained reinforcing material side semi-finished product can be directly used for bonding to the back of the printed wiring board, or it can be pasted with a release film for storage, and then used for bonding to the base film side semi-finished product.

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 explained in more detail with examples. However, the present invention is not limited by the embodiments. In the examples and comparative examples, the parts by mass are abbreviated as parts.

(Physical property evaluation method)

[Acid value (a) component: acid-modified polyolefin] The acid value (mgKOH/g) in the present invention is that the acid-modified polyolefin is dissolved in toluene, and the methanol solution of sodium methoxide is titrated with phenolphthalein as an indicator.

[Number average molecular weight (Mn)] The number average molecular weight in the present invention uses a gel permeation chromatograph manufactured by Shimadzu Corporation (hereinafter referred to as GPC, standard material: polystyrene resin, mobile phase: tetrahydrofuran, column: Shodex KF-802 + KF-804L) + KF-806L, column temperature: 30°C, flow rate: 1.0ml/min, detector: RI detector).

[Determination of melting point and heat of fusion] The melting point and heat of fusion in the present invention are based on a differential scanning calorimeter (hereinafter referred to as DSC, manufactured by TA Instruments Japan, Q-2000). The temperature is raised and melted at a rate of 20°C/min, and the resin is cooled and then converted into a resin. The value measured at the peak temperature and area of the melting peak at the time of heating and melting.

(1) Peel strength (adhesiveness) The adhesive composition described below is 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 becomes 25 μm And dry at 130°C for 3 minutes. The adhesive film (B-stage product) prepared in this way and a rolled copper foil (manufactured by JX Metal Co., Ltd., BHY series) with a thickness of 18 μm were bonded together. The bonding is carried out by rolling the glossy surface of the copper foil in contact with the adhesive layer, and pressing for 30 seconds ^{at 160°C and 40 kgf/cm 2 for bonding.} Then, it was heat-treated at 140° C. for 4 hours to be hardened, and a sample for peeling strength evaluation was obtained. For 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. In addition, liquid crystal polymer (LCP) films (manufactured by Curaray Co., Ltd., BEXTOR CT-Z series, thickness 50 μm) and parallel polystyrene (SPS) films (thickness 100 μm) were also prepared in the same manner. <Evaluation criteria (PI film and LCP film)> ◎: 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 <Evaluation criteria (SPS film)> ◎: 0.7N/mm or more ○: 0.5N/mm or more and less than 0.7N/mm △: 0.3N/mm or more and less than 0.5N/mm ×: not Up to 0.3N/mm

(2) Solder heat resistance Prepare the sample in the same way as above. The 2.0cm×2.0cm sample piece is aged at 23°C for 2 days, and then floated in a solder bath melted at 280°C for 10 seconds, and check whether there is swelling Wait for the appearance change. <Evaluation criteria> ◎: No swelling ○: Some swelling △: There is a lot of bulging ×: swelling and discoloration

(3) Relative permittivity (ε _c ) and dielectric loss tangent (tanδ) Apply the adhesive composition described later to a Teflon (registered trademark) sheet with a thickness of 100μm, so that the thickness after drying and curing becomes 25μm And dry at 130°C for 3 minutes. Then, after heat treatment at 140°C for 4 hours to harden, the Teflon (registered trademark) sheet was peeled off to obtain an adhesive resin sheet for testing. After that, the sample was cut so that the obtained test adhesive resin sheet became a strip of 8 cm×3 mm to obtain a test sample. The relative permittivity (ε _c ) and the dielectric loss tangent (tanδ) were measured using a Network Analyzer (manufactured by Anritsu) by the cavity perturbation method at a temperature of 23° C. and a frequency of 1 GHz. <Evaluation criteria of relative permittivity> ◎: 2.3 or less ○: more than 2.3 and less than 2.6 △: more than 2.6 and less than 3.0 ×: more than 3.0 <evaluation criteria of dielectric loss tangent> ◎: less than 0.008 ○: more than 0.008 And less than 0.01 △: more than 0.01 and less than 0.02 ×: more than 0.02

(4) Pot life characteristics The pot life characteristic means that the components (a) ~ (d) and the mixed solvent of methylcyclohexane and toluene (methylcyclohexane/toluene=80/20(v/v)) are used to make the solid content concentration 20 It is blended in mass% to prepare a resin solution (varnish), and the stability of the varnish immediately after blending or after a certain period of time has elapsed after blending. The case with good pot life characteristics means that the viscosity of the varnish rises little and can be stored for a long time. The case of poor pot life characteristics means the viscosity of the varnish rises (tackification). In severe cases, it will cause gelation and it is difficult to apply to the base. It cannot be stored for a long time. The varnish prepared according to the ratio in Table 1 was measured using a Brookfield viscometer with a No. 2 spindle rotor at a rotation speed of 30 rpm to determine the dispersion viscosity at 25° C. to obtain the initial dispersion viscosity ηB0. Thereafter, the varnish was stored at 25°C for 7 days, and the dispersion viscosity ηB was measured at 25°C. The varnish viscosity was calculated using the following formula, and evaluated as follows. Solution viscosity ratio = solution viscosity ηB/solution viscosity ηB0 <Evaluation criteria> ◎: 0.5 or more and less than 1.5 ○: 1.5 or more and less than 2.0 △: 2.0 or more and less than 3.0 ×: 3.0 or more or the viscosity cannot be measured due to pudding

[Example 1] Blended with 80 parts by mass of acid-modified polyolefin CO-1, 20 parts by mass of phenolic resin FTC-509 with polycyclic structure, 10 parts by mass of epoxy resin HP-7200, and 440 parts by mass of organic solvent (methyl Cyclohexane/toluene=80/20(v/v)) (solid content concentration is 20% by mass) to obtain an adhesive composition. The blending amount, bonding strength, solder heat resistance, and electrical properties are shown in Table 1.

[Examples 2~18] The type and ratio of the resin used were changed as shown in Table 1, and Examples 2 to 18 were performed in the same manner as in Example 1. Adhesive strength, solder heat resistance, electrical characteristics and pot life characteristics are shown in Table 1. In addition, the organic solvent (methylcyclohexane/toluene=80/20 (v/v)) was adjusted so that the solid content concentration became 20% by mass.

[Comparative Examples 1~4] The type and ratio of the resin used were changed as shown in Table 1, and Comparative Examples 1 to 4 were performed in the same manner as in Example 1. Adhesive strength, solder heat resistance, electrical characteristics and pot life characteristics are shown in Table 1.

[Table 1] Example Example Example Example Example Example Example Example Example Example Example Example Example Example Example Example Example Example Comparative example Comparative example Comparative example Comparative example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 1 2 3 4 Acid-modified polyolefin (a) (parts by mass) CO-1 80 80 80 95 70 50 80 80 80 80 80 80 80 80 80 100 80 80 CO-2 80 CO-3 80 CO-4 80 Phenolic resin (b) (parts by mass) (b1)FTC509 20 20 20 20 5 30 50 20 20 20 20 20 20 20 20 20 20 100 (b2)FATC 20 (b3)FTC-809AE 20 (b4)T-100 20 Epoxy resin (c) (parts by mass) HP-7200 10 10 10 10 10 10 10 10 10 10 1 58 10 15 5 10 10 10 HP-7200H 10 jER-152 10 5 jER-630 10 Polycarbodiimide (d) (parts by mass) V-09GB 3 18 V-03 3 Bonding strength (PI/Ad/Cu) Evaluation ◎ ◎ 〇 〇 ◎ ◎ ◎ ◎ 〇 ◎ ◎ ◎ ◎ △ ◎ ◎ ◎ ◎ ◎ ◎ 〇 X Solder heat resistance (PI/Ad/Cu) Evaluation 〇 〇 〇 〇 ◎ 〇 △ ◎ ◎ 〇 〇 〇 △ 〇 〇 〇 〇 ◎ X 〇 X 〇 Bonding strength (LCP/Ad/Cu) Evaluation ◎ ◎ 〇 〇 ◎ ◎ ◎ ◎ 〇 ◎ ◎ ◎ ◎ △ ◎ ◎ ◎ ◎ ◎ ◎ 〇 X Solder heat resistance (LCP/Ad/Cu) Evaluation 〇 〇 〇 〇 ◎ 〇 △ ◎ ◎ 〇 〇 〇 △ 〇 〇 〇 〇 〇 X 〇 X 〇 Bonding strength (SPS/Ad/Cu) Evaluation 〇 〇 〇 〇 〇 〇 〇 ◎ 〇 ◎ 〇 〇 〇 △ ◎ ◎ 〇 ◎ ◎ ◎ 〇 X Solder heat resistance (SPS/Ad/Cu) Evaluation 〇 〇 〇 〇 ◎ 〇 △ ◎ ◎ 〇 〇 〇 △ 〇 〇 〇 〇 〇 X 〇 X 〇 Electrical characteristics Relative permittivity ◎ ◎ ◎ ◎ ◎ ◎ ◎ 〇 〇 ◎ ◎ ◎ ◎ △ ◎ 〇 ◎ ◎ ◎ X ◎ X Dielectric loss tangent ◎ ◎ ◎ ◎ ◎ ◎ ◎ 〇 △ ◎ ◎ ◎ ◎ △ ◎ 〇 ◎ ◎ ◎ X ◎ 〇 Pot life characteristics initial 〇 ◎ ◎ ◎ 〇 〇 ◎ 〇 〇 〇 〇 〇 ◎ △ 〇 〇 〇 〇 ◎ ◎ ◎ ◎ 25℃×1 week later 〇 〇 〇 ◎ 〇 〇 〇 〇 〇 〇 〇 〇 ◎ △ 〇 〇 〇 〇 ◎ 〇 ◎ ◎

The acid-modified polyolefin (a), phenol resin (b) having a polycyclic structure, epoxy resin (c), and polycarbodiimide (d) used in Table 1 are as follows. (Phenolic resin with polycyclic structure (b)) Phenolic resin (b1): FTC-509 (manufactured by Kunei Chemical Industry Co., Ltd.), a phenol resin having structures of general formula (2) and general formula (11). Both x and y are 0, Z ₁ is 1, and the hydroxyl group is bonded to the para position of the benzyl group. Phenolic resin (b2): FATC-809 (manufactured by Gunei Chemical Industry Co., Ltd.), a phenol resin having structures of general formula (2) and general formula (11). R ₃ and R ₄ are all 2-propenyl groups, x, y, and Z ₁ are all 1, and the hydroxyl group is bonded to the para position of the benzyl group. Phenolic resin (b3): FTC-809AE (manufactured by Kunei Chemical Industry Co., Ltd.), a phenol resin having structures of general formula (2) and general formula (12). Both x and y are 0, Z ₁ and Z ₂ are both 1, and the ether group is bonded to the para position of the benzyl group. Phenolic resin (b4): YS POLYSTAR T-100 (a phenolic resin that does not contain a polycyclic structure manufactured by Yasuhara Chemical) (Epoxy resin (c)) Dicyclopentadiene type epoxy resin: HP-7200 (ring manufactured by DIC) Oxygen equivalent 259g/eq) Dicyclopentadiene epoxy resin: HP-7200H (DIC company’s epoxy equivalent 278g/eq) Cresol novolac epoxy resin: jER-152 (Mitsubishi Chemical epoxy equivalent 177g/ eq) Triglycidyl-p-aminophenol: jER-630 (Mitsubishi Chemical's epoxy equivalent 98g/eq) (Polycarbodiimide (d)) Carbodiimide resin: V-09GB (Nisshinbo Chemical Co., Ltd.) Carbodiimide equivalent 216g/eq) Carbodiimide resin: V-03 (Carbodiimide equivalent 209g/eq manufactured by Nisshinbo Chemical Co., Ltd.)

(Acid modified polyolefin (a)) [Manufacturing Example 1] In a 1L autoclave, 100 parts by mass of propylene-butene copolymer ("TAFMER (registered trademark) XM7080" manufactured by Mitsui Chemicals Co., Ltd.), 150 parts by mass of toluene, and 19 parts by mass of maleic anhydride were added , 6 parts by mass of two (tertiary butyl) peroxide, heated to 140° C., and then stirred for another 3 hours. After that, the obtained reaction liquid was cooled, and then poured into a container filled with a large amount of methyl ethyl ketone to precipitate the resin. Thereafter, by centrifuging the liquid containing the resin, the acid-modified propylene-butene copolymer graft-polymerized with maleic anhydride, (poly)maleic anhydride and low molecular weight substances are separated and purified. Thereafter, it was dried under reduced pressure at 70°C for 5 hours to obtain a maleic anhydride modified propylene-butene copolymer (CO-1, acid value 19mgKOH/g, number average molecular weight 25,000, Tm80°C, △H35J/ g).

[Manufacturing Example 2] Except that the feed amount of maleic anhydride was changed to 14 parts by mass, the same procedure as in Production Example 1 was carried out to obtain a maleic anhydride-modified propylene-butene copolymer (CO-2, acid value 14mgKOH/ g, number average molecular weight 30,000, Tm78°C, △H25J/g).

[Manufacturing Example 3] Except that the feed amount of maleic anhydride was changed to 11 parts by mass, the same procedure as in Production Example 1 was carried out to obtain a maleic anhydride-modified propylene-butene copolymer (CO-3, acid value 11mgKOH/ g, number average molecular weight 33,000, Tm80℃, △H25J/g).

[Manufacturing Example 4] Except that the feed amount of maleic anhydride was changed to 6 parts by mass, the same procedure as in Production Example 1 was carried out to obtain a maleic anhydride-modified propylene-butene copolymer (CO-4, acid value 7mgKOH/ g, number average molecular weight 35,000, Tm 82°C, △H25J/g).

It can be seen from Table 1 that in Examples 1-18, the main agent has excellent pot life characteristics. As far as the adhesive is concerned, it has excellent adhesion to the resin substrate (PI, LCP, SPS) and copper foil, and the solder heat resistance Sex, and low dielectric properties. In contrast, in Comparative Example 1, the component (b) was not blended, so the solder had poor heat resistance. In Comparative Example 2, the component (b) does not have a polycyclic structure, so the low dielectric properties (electrical properties) are inferior. In Comparative Example 3, since the component (c) is not included, the solder has poor heat resistance. In Comparative Example 4, the component (a) was not blended, so the bonding strength with each substrate was poor and the low dielectric properties were poor. [Industrial Utilization]

The adhesive composition of the present invention has high adhesion not only to conventional polyimide and polyethylene terephthalate films, but also to resin substrates such as LCP and SPS, and to metal substrates such as copper foil. High solder heat resistance, pot life characteristics and low dielectric characteristics (electrical characteristics) are also excellent. The adhesive composition of the present invention can obtain an adhesive sheet and a laminate formed by bonding the adhesive sheet. Due to the above characteristics, it is effective for flexible printed wiring board applications, especially for FPC applications that require low dielectric properties (low dielectric constant, low dielectric loss tangent) in the high-frequency region.

Claims (11)

An adhesive composition containing: Acid-modified polyolefin (a), Phenolic resin (b) with polycyclic structure, and Epoxy resin (c). The adhesive composition of claim 1, wherein the phenol resin (b) having a polycyclic structure is a phenol resin having a tricyclodecane skeleton. The adhesive composition of claim 1 or 2, wherein the phenol resin (b) having a polycyclic structure is a phenol resin having a carbonate skeleton. Such as the adhesive composition of claim 1 or 2, wherein the acid value of the acid-modified polyolefin (a) is 5-40 mgKOH/g. The adhesive composition of claim 1 or 2, which further contains polycarbodiimide (d). The adhesive composition of claim 1 or 2, wherein, relative to 100 parts by mass of the acid-modified polyolefin (a), it contains 0.05 to 120 parts by mass of the phenolic resin (b) having a polycyclic structure, and 0.1~ 60 parts by mass of epoxy resin (c). The adhesive composition of claim 5, which contains 0.1-30 parts by mass of polycarbodiimide (d) relative to 100 parts by mass of acid-modified polyolefin (a). For example, the adhesive composition of claim 1 or 2 has a relative dielectric constant (ε _c ) of 3.0 or less at 1 GHz, and a dielectric loss tangent (tanδ) of 0.02 or less. An adhesive sheet containing the adhesive composition according to any one of claims 1 to 8. A laminated body containing the adhesive composition according to any one of claims 1 to 8. A printed wiring board containing a laminated body as in claim 10 as a constituent element.