JP2022125999A - Polyimide resin composition, adhesive composition, film-like adhesive, adhesive sheet, copper foil with resin, copper-clad laminate, printed wiring board, and polyimide film - Google Patents

Abstract

To provide a polyimide resin composition that allows an organic solvent to easily volatilize during drying with heating, even when an organic solvent containing a nitrogen atom and an aromatic hydrocarbon are not used, and gives a polyimide resin layer having low dielectric constants and low dielectric loss tangents, and excellent solder heat resistance.SOLUTION: A polyimide resin composition contains a polyimide (A), which is a reactant of a monomer group containing an aromatic tetracarboxylic acid anhydride (a1) and a diamine containing a dimer diamine (a2), and two or more different organic solvents (B). The component (B) includes an ester (B1) and at least one organic solvent (B2) selected from the group consisting of a ketone, an ether, an aliphatic hydrocarbon and an alicyclic hydrocarbon.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a polyimide resin composition, an adhesive composition, a film adhesive, an adhesive sheet, a resin-coated copper foil, a copper-clad laminate, a printed wiring board, and a polyimide film.

Flexible printed wiring boards (FPWB: Flexible Printed Wiring Board), printed circuit boards (PCB: Printed Circuit Board), and multilayer wiring boards using them are used in mobile communication devices such as mobile phones and smart phones, base station devices thereof, and servers.・It is widely used in products such as network-related electronic devices such as routers and large computers.

In recent years, these products use high-frequency electrical signals to transmit and process large amounts of information at high speed. It is necessary to devise ways to reduce losses as much as possible.

As a means for suppressing transmission loss in a multilayer wiring board, for example, when laminating a printed wiring board or a printed circuit board, an adhesive having a property that both the dielectric constant and the dielectric loss tangent are small (hereinafter also referred to as low dielectric property) It is conceivable to use a polyimide resin as the composition.

As such a polyimide, a resin having a tetracarboxylic acid residue and a diamine residue derived from dimer acid for forming an adhesive layer in a metal-clad laminate having an insulating resin layer, an adhesive layer, and a metal layer is used. It is known (Patent Document 1). Since the polyimide has an aromatic ring, it exhibits excellent solder heat resistance.

By the way, in the production of FPWB, etc., a process of applying an adhesive composition to a support such as release polyethylene terephthalate (release PET) or release paper and drying it under heat is performed. Due to its poor heat resistance, its drying is usually carried out at temperatures below 150°C. Based on this, N-methylpyrrolidone (NMP) and xylene are used as organic solvents in the production of the polyimide of Patent Document 1. However, since an organic solvent containing nitrogen atoms such as NMP has a high boiling point, it tends to remain when the resin composition is dried at the above temperature, and tends to adversely affect the low dielectric properties and solder heat resistance of the polyimide resin layer. Aromatic hydrocarbons such as xylene are harmful to the human body and the environment, and are therefore not preferable for use.

JP 2018-140544 A

The present invention provides a solder that easily volatilizes an organic solvent and has a low dielectric constant and a low dielectric loss tangent in drying under heating without using an organic solvent and an aromatic hydrocarbon containing nitrogen atoms. An object of the present invention is to provide a polyimide resin composition that provides a polyimide resin layer having heat resistance.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, when this inventor carried out earnest examination, in the combination of a specific organic solvent, it discovered that the said subject was solved, and came to complete this invention. That is, the present invention provides the following.

1. A polyimide resin composition containing a polyimide (A) which is a reactant of a monomer group containing an aromatic tetracarboxylic anhydride (a1) and a diamine (a2) containing a dimer diamine, and two or more different organic solvents (B) being a thing,
Component (B) is a polyimide resin composition containing an ester (B1) and at least one organic solvent (B2) selected from the group consisting of ketones, ethers, aliphatic hydrocarbons and alicyclic hydrocarbons.

2. 1. The polyimide resin composition according to the preceding item 1, wherein the component (a2) further contains an alicyclic diamine and/or an aromatic diamine.

3. 3. The polyimide resin composition according to item 1 or 2, wherein the content ratio of the component (B1) and the component (B2) is (B1)/(B2)=10/90 to 90/10 in mass ratio.

4. The polyimide resin composition according to any one of the preceding items 1 to 3, wherein the component (B) does not contain an aromatic hydrocarbon.

5. 5. The polyimide resin composition according to any one of the preceding items 1 to 4, wherein the component (B1) is an aliphatic ester.

6. An adhesive composition comprising the polyimide resin composition according to any one of 1 to 5 above and a cross-linking agent.

7. 7. A film adhesive comprising a cured product of the adhesive composition as described in 6 above.

8. An adhesive sheet having the film-like adhesive of the preceding item 7 on at least one side of a support film.

9. 8. A resin-coated copper foil comprising the film-like adhesive according to 7 above and a copper foil.

10. A copper-clad laminate comprising the resin-coated copper foil according to 9 above and a copper foil or an insulating sheet.

11. 11. A printed wiring board having a circuit pattern on the copper foil surface of the copper-clad laminate according to 10 above.

12. A polyimide film, which is a cured product of the polyimide resin composition according to any one of 1 to 5 above.

According to the polyimide resin composition of the present invention, even if the organic solvent and aromatic hydrocarbon containing nitrogen atoms are not used, the organic solvent is easily volatilized in drying under heating, and the low dielectric constant and low It provides a polyimide resin layer having dielectric loss tangent and excellent solder heat resistance.

The polyimide resin composition of the present invention contains an aromatic tetracarboxylic anhydride (a1) (hereinafter referred to as (a1) component) and a diamine (a2) containing dimer diamine (hereinafter referred to as (a2) component). It contains polyimide (A) (hereinafter referred to as component (A)), which is a reactant of the monomer group.

Component (a1) is not particularly limited, and examples include 2,2′,3,3′-biphenyltetracarboxylic dianhydride, 2,3′,3,4′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic anhydride, 3,3′,4,4′- Diphenylsulfonetetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 4,4'-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic dianhydride, 2,2 ',3,3'-benzophenonetetracarboxylic dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride , 2,3′,3,4′-diphenyl ether tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis (3,4-dicarboxyphenyl)methane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, bis(2,3-dicarboxyphenoxyphenyl) ) sulfone dianhydride, bis(3,4-dicarboxyphenoxyphenyl) sulfone dianhydride, 1,4,5,8-naphthalenetetracarboxylic anhydride, 2,3,6,7-naphthalenetetracarboxylic anhydride 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic acid dianhydride Anhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 2,2-bis(3,3′,4,4′-tetracarboxyphenyl)tetrafluoropropane dianhydride etc. These may be used alone or in combination of two or more.

（式（１）中、Ｘは単結合、－ＳＯ_２－、－ＣＯ－、－Ｏ－、－Ｏ－Ｃ_６Ｈ_４－Ｃ（ＣＨ_３）_２－Ｃ_６Ｈ_４－Ｏ－、－Ｃ（ＣＨ_３）_２－、－Ｏ－Ｃ_６Ｈ_４－ＳＯ_２－Ｃ_６Ｈ_４－Ｏ－、－Ｃ（ＣＨＦ₂）_２－、－Ｃ（ＣＦ_３）_２－、－ＣＯＯ－（ＣＨ_２）_ｐ－ＯＣＯ－、又は－ＣＯＯ－Ｈ_２Ｃ－ＨＣ（－Ｏ－Ｃ（＝Ｏ）－ＣＨ_３）－ＣＨ_２－ＯＣＯ－を表し、ｐは１～２０の整数を表す。） Among them, the component (a1) is preferably represented by the following general formula (1) from the viewpoint of the flexibility of the polyimide resin layer and the resistance to soldering heat.

(In formula (1), X is a single bond, —SO ₂ —, —CO—, —O—, —OC ₆ H ₄ —C(CH ₃ ) ₂ —C ₆ H ₄ —O—, —C (CH ₃ ) ₂ —, —O—C ₆ H ₄ —SO ₂ —C ₆ H ₄ —O—, —C(CHF ₂ ) ₂ —, —C(CF ₃ ) ₂ —, —COO—(CH ₂ ) _p -OCO- or -COO-H ₂ C-HC(-OC(=O)-CH ₃ )-CH ₂ -OCO-, p represents an integer of 1 to 20.)

Examples of those represented by the general formula (1) include 2,2′,3,3′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-diphenyl ether tetracarboxylic acid acid dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 2,2-bis(3,3',4,4'-tetracarboxyphenyl)tetrafluoropropane anhydride, 4,4′-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2'-bis(3,4-dicarboxyphenoxyphenyl)sulfone dianhydride and the like. These may be used alone or in combination of two or more. Among them, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 4,4'-[propane-2,2 -diylbis(1,4-phenyleneoxy)]diphthalic dianhydride is preferred.

The amount of component (a1) used in 100 mol % of the monomer group constituting component (A) is not particularly limited, and is usually 10 to 90 mol %, preferably 25 to 75 mol %.

In addition, the amount of the tetracarboxylic anhydride represented by the general formula (1) in 100 mol% of the monomer group constituting the component (A) is not particularly limited, and is usually 10 to 90 mol%, preferably , from 25 to 75 mol %.

The amount of the tetracarboxylic acid anhydride represented by the general formula (1) used in 100 mol % of component (a1) is not particularly limited, and is usually 10 to 100 mol %, preferably 50 to 100 mol %. be.

The (a2) component is a diamine including dimer diamine.

A dimer diamine is a dimer acid in which all the carboxyl groups are substituted with primary amino groups or primary aminomethyl groups (see, for example, JP-A-9-12712). Here, the dimer acid mainly contains a dibasic acid having 36 carbon atoms obtained by dimerizing unsaturated fatty acids such as oleic acid, linoleic acid and linolenic acid. It contains 18 monomer acids, 54 carbon trimer acids, and 20-90 carbon polymerized fatty acids. Although the dimer acid contains a double bond, the degree of unsaturation may be reduced by, for example, a hydrogenation reaction.

The dimer diamine is not particularly limited, and examples thereof include those represented by the following general formula (2). In general formula (2), m+n=6 to 17 is preferable, p+q=8 to 19 is preferable, and the dashed line means a carbon-carbon single bond or a carbon-carbon double bond.

Commercially available dimer diamines include "Versamin 551", "Versamin 552" (manufactured by Cognix Japan Co., Ltd.), "PRIAMINE 1073", "PRIAMINE 1074", and "PRIAMINE 1075" (manufactured by Croda Japan Co., Ltd.). made) and the like.

Furthermore, the dimer diamine may be used as it is, or may be used after being purified by distillation or the like.

The amount of dimer diamine to be used in 100 mol % of the monomer group constituting component (A) is not particularly limited, and is usually 5 mol % or more, preferably 25 to 75 mol %.

The amount of dimer diamine used in 100 mol % of component (a2) is not particularly limited, and is usually 10 mol % or more, preferably 30 to 100 mol %.

The component (a2) may also contain a diamine (a2-1) (hereinafter referred to as component (a2-1)) other than dimer diamine. Component (a2-1) may include, for example, aliphatic diamines, alicyclic diamines, aromatic diamines, diaminoethers, and diaminopolysiloxanes. These amines exclude dimer diamines.

Examples of aliphatic diamines include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diamino octane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane and the like.

Alicyclic diamines include, for example, diaminocyclohexane, diaminodicyclohexylmethane, dimethyldiaminodicyclohexylmethane, diaminodicyclohexylpropane, tetramethyldiaminodicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl ) cyclohexane, diaminobicyclo[2.2.1]heptane, bis(aminomethyl)-bicyclo[2.2.1]heptane, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2 .1.0(2,6)]decane, isophoronediamine and the like.

Examples of aromatic diamines include
2,2'-diaminobiphenyl, 3,3'-diaminobiphenyl, 4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4' -diaminobiphenyls such as diaminobiphenyl, 2,2'-di-n-propyl-4,4'-diaminobiphenyl;
bisaminophenoxyphenylpropanes such as 2,2-bis[4-(3-aminophenoxy)phenyl]propane and 2,2-bis[4-(4-aminophenoxy)phenyl]propane;
diaminodiphenyl ethers such as 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl ether;
Phenylenediamines such as p-phenylenediamine and m-phenylenediamine;
Diaminodiphenyl sulfides such as 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide;
Diaminodiphenyl sulfones such as 3,3′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfone;
Diaminobenzophenones such as 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,4′-diaminobenzophenone;
Diaminodiphenylmethanes such as 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, bis[4-(3-aminophenoxy)phenyl]methane;
Diaminophenylpropanes such as 2,2-di(3-aminophenyl)propane, 2,2-di(4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane;
2,2-di(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-di(4-aminophenyl)-1,1,1,3,3, diaminophenyl hexafluoropropanes such as 3-hexafluoropropane, 2-(3-aminophenyl)-2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane;
1,1-di(3-aminophenyl)-1-phenylethane, 1,1-di(4-aminophenyl)-1-phenylethane, 1-(3-aminophenyl)-1-(4-aminophenyl )-diaminophenylphenylethane such as 1-phenylethane;
1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy) bisaminophenoxybenzenes such as benzene;
1,3-bis(3-aminobenzoyl)benzene, 1,3-bis(4-aminobenzoyl)benzene, 1,4-bis(3-aminobenzoyl)benzene, 1,4-bis(4-aminobenzoyl) bisaminobenzoylbenzenes such as benzene;
1,3-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(3-amino-α, bisaminodimethylbenzylbenzenes such as α-dimethylbenzyl)benzene, 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene;
1,3-bis(3-amino-α,α-ditrifluoromethylbenzyl)benzene, 1,3-bis(4-amino-α,α-ditrifluoromethylbenzyl)benzene, 1,4-bis(3- bisaminoditrifluoromethylbenzylbenzenes such as amino-α,α-ditrifluoromethylbenzyl)benzene, 1,4-bis(4-amino-α,α-ditrifluoromethylbenzyl)benzene;
aminophenoxybiphenyls such as 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, bis[1-(3-aminophenoxy)]biphenyl;
aminophenoxyphenyl ketones such as bis[4-(3-aminophenoxy)phenyl]ketone and bis[4-(4-aminophenoxy)phenyl]ketone;
aminophenoxyphenyl sulfides such as bis[4-(3-aminophenoxy)phenyl]sulfide and bis[4-(4-aminophenoxy)phenyl]sulfide;
aminophenoxyphenyl sulfones such as bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone;
aminophenoxyphenyl ethers such as bis[4-(3-aminophenoxy)phenyl]ether and bis[4-(4-aminophenoxy)phenyl]ether;
2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane , 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane;
1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-aminophenoxy) bis(aminophenoxybenzoyl)benzenes such as benzoyl]benzene, 1,4-bis[4-(4-aminophenoxy)benzoyl]benzene;
1,3-bis[4-(3-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1, 4-bis[4-(3-aminophenoxy)-α,α-dimethylbenzyl]benzene, bis(amino phenoxy-α,α-dimethylbenzyl)benzene;
bis[(aminoaryloxy)benzoyl]diphenyl ether such as 4,4′-bis[4-(4-aminophenoxy)benzoyl]diphenyl ether;
Bis(amino-α,α-dimethylbenzylphenoxy)benzophenones such as 4,4′-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone:
bis[amino-α,α-dimethylbenzylphenoxy]diphenylsulfone such as 4,4′-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenylsulfone;
bis[aminophenoxyphenoxy]diphenylsulfone such as 4,4′-bis[4-(4-aminophenoxy)phenoxy]diphenylsulfone;
diaminodiaryloxybenzophenones such as 3,3′-diamino-4,4′-diphenoxybenzophenone and 3,3′-diamino-4,4′-dibiphenoxybenzophenone;
Diaminoaryloxybenzophenones such as 3,3′-diamino-4-phenoxybenzophenone and 3,3′-diamino-4-biphenoxybenzophenone;
1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-5-amine, 9,9-bis(4-aminophenyl)fluorene and the like.

Examples of diamino ethers include bis (aminomethyl) ether, bis (2-aminoethyl) ether, bis (3-aminopropyl) ether, bis [(2-aminomethoxy) ethyl] ether, bis [2- (2-aminoethoxy)ethyl]ether, bis[2-(3-aminoprotoxy)ethyl]ether, 1,2-bis(aminomethoxy)ethane, 1,2-bis(2-aminoethoxy)ethane, 1 , 2-bis[2-(aminomethoxy)ethoxy]ethane, 1,2-bis[2-(2-aminoethoxy)ethoxy]ethane, ethylene glycol bis(3-aminopropyl) ether, diethylene glycol bis(3 -aminopropyl) ether, triethylene glycol bis(3-aminopropyl) ether and the like.

Examples of diaminopolysiloxane include α,ω-bis(2-aminoethyl)polydimethylsiloxane, α,ω-bis(3-aminopropyl)polydimethylsiloxane, α,ω-bis(4-aminobutyl)poly Dimethylsiloxane, α,ω-bis(5-aminopentyl)polydimethylsiloxane, α,ω-bis[3-(2-aminophenyl)propyl]polydimethylsiloxane, α,ω-bis[3-(4-amino phenyl)propyl]polydimethylsiloxane and the like.

These (a2-1) components may be used alone or in combination of two or more. Among them, alicyclic diamines and aromatic diamines are preferred, and aromatic diamines are more preferred, since the polyimide resin layer exhibits excellent solder heat resistance.

The amount of component (a2-1) used in 100 mol % of the monomer group constituting component (A) is not particularly limited, and is usually 90 mol % or less, preferably 50 mol % or less.

The amount of component (a2-1) used in 100 mol % of component (a2) is not particularly limited, and is usually 90 mol % or less, preferably 70 mol % or less.

The (A) component of the present invention can be obtained by various known production methods. As the production method thereof, for example, a monomer group containing components (a1) and (a2) is heated at a temperature of preferably about 30 to 120° C., more preferably about 40 to 100° C., for a time of preferably 0.1 to 100° C. A step of conducting a polyaddition reaction for about 2 hours, more preferably about 0.1 to 0.5 hours to obtain a polyadduct. A method including a step of imidization reaction, ie dehydration ring closure reaction, at a temperature of about 170° C. for preferably about 0.5 to 50 hours, more preferably about 1 to 20 hours. The method and order of mixing the components (a1) and (a2) are not particularly limited.

In addition, in the imidization reaction step, various known reaction catalysts, dehydrating agents, and organic solvents (B) described below may be used, and these may be used alone or in combination of two or more.

Examples of reaction catalysts include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, and heterocyclic tertiary amines such as pyridine, picoline and isoquinoline. The dehydrating agent includes aliphatic carboxylic acid anhydrides such as acetic anhydride and aromatic carboxylic acid anhydrides such as benzoic anhydride.

When the organic solvent (B) described below is used in the production of component (A), the amount used is adjusted so that the reaction concentration is 5 to 60% by mass, preferably 20 to 50% by mass. be.

Although the imide ring closure rate of component (A) is not particularly limited, it is preferably 90 to 100%, more preferably about 95 to 100%, in terms of obtaining component (A) having both high softening point and flexibility.
It is presumed that when the imide ring closure rate of component (A) is within the above range, component (A) is likely to form hard segment and soft segment structures, and both softening point and flexibility are increased. Here, the "imido ring closure rate" means the content of cyclic imide bonds in the polyimide resin of component (A), and can be determined by various spectroscopic means such as NMR and IR analysis.

The physical properties of component (A) are not particularly limited. The weight average molecular weight of component (A) is preferably 20,000 to 100,000. Component (A) preferably has a number average molecular weight of 5,000 to 50,000. A weight average molecular weight and a number average molecular weight are calculated|required as a polystyrene conversion value measured by a gel permeation chromatography (GPC), for example.

The softening point of the component (A) of the present invention is preferably about 50 to 250° C., more preferably about 80 to 200° C., from the viewpoint of facilitating press hardening during the production of laminates such as copper-clad laminates. . The softening point is the temperature at which the storage modulus begins to decrease in the storage modulus profile measured using a commercially available measuring instrument (product name “ARES-2KSTD-FCO-STD”, manufactured by Rheometric Scientific). Point.

The polyimide resin composition of the present invention contains two or more different organic solvents (B) (hereinafter referred to as component (B)).

The content of the component (B) in the polyimide resin composition of the present invention is not particularly limited, but it is preferably 50 to 1000 parts by mass (in terms of non-volatile content) with respect to 100 parts by mass of the polyimide resin composition. , 100 to 400 parts by mass (in terms of non-volatile content).

Component (B) is an ester (B1) (hereinafter referred to as component (B1)) and at least one organic solvent (B2 ) (hereinafter referred to as component (B2)).

As the component (B1), as long as it is an ester, various known ones can be used. Specific examples include aliphatic esters, alicyclic esters, and aromatic esters. The term "aliphatic ester" as used herein means an ester having no cyclic structure, and includes carbonic acid alkyl esters such as dimethyl carbonate and diethyl carbonate. Among them, the component (B1) preferably has a boiling point of 60°C or higher and 150°C or lower. When the component (B1) has the above boiling point, the component (B1) does not volatilize when the polyimide resin composition or the adhesive composition containing the composition is applied to the support film or copper foil. It is possible to prevent the occurrence of process irregularities and voids. In addition, since the coating layer of these compositions is easily volatilized when dried, the component (B1) does not remain in the resulting cured product layer, and as a result, low dielectric properties are also exhibited. Become. The upper limit and lower limit of the boiling point include 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, etc. . For the same reason as above, the boiling point of component (B1) is more preferably 70°C or higher and 140°C or lower. The above boiling point is the value at normal pressure, and the one described in the chemical manufacturer's catalog and Chemical Book was adopted (the same applies hereinafter).

Among preferred components (B1), aliphatic esters include, for example, n-propyl formate (80°C), isopropyl formate (68°C), n-butyl formate (106°C), isobutyl formate (98°C), and sec formate. -butyl (99°C), tert-butyl formate (82°C), n-pentyl formate (130°C), isopentyl formate (124°C), ethyl acetate (77°C), n-propyl acetate (102°C), isopropyl acetate (89°C), n-butyl acetate (126°C), isobutyl acetate (118°C), sec-butyl acetate (112°C), tert-butyl acetate (97°C), n-pentyl acetate (149°C), isopentyl acetate (142°C), sec-pentyl acetate (121°C), tert-pentyl acetate (123°C), methyl propionate (80°C), ethyl propionate (99°C), n-propyl propionate (123°C), propionate Isopropyl acid (108°C), n-butyl propionate (145°C), isobutyl propionate (138°C), sec-butyl propionate (133°C), tert-butyl propionate (118°C), methyl butyrate (102°C) ), ethyl butyrate (121°C), n-propyl butyrate (143°C), isopropyl butyrate (129°C), methyl isobutyrate (92°C), ethyl isobutyrate (112°C), n-propyl isobutyrate (134°C) , isopropyl isobutyrate (120°C), isobutyl isobutyrate (147°C), sec-butyl isobutyrate (112°C), methyl valerate (126°C), ethyl valerate (145°C), methyl hexanoate (150°C) , dimethyl carbonate (90° C.), ethyl methyl carbonate (107° C.), diethyl carbonate (126° C.) and the like. The temperature in parentheses represents the boiling point of each compound under normal pressure (the same applies hereinafter).

Among preferred components (B1), alicyclic esters include methyl cyclopropanecarboxylate (119°C), ethyl cyclopropanecarboxylate (131°C), and methyl cyclobutanecarboxylate (135°C).

These (B1) components may be used alone or in combination of two or more. Of these, aliphatic esters are preferred, and n-butyl acetate and diethyl carbonate are more preferred, from the viewpoint of good compatibility between component (A) and component (B1).

As component (B2), various known ketones, ethers, aliphatic hydrocarbons, and alicyclic hydrocarbons can be used. These (B2) components may be used alone or in combination of two or more. Among them, the component (B2) preferably has a boiling point of 60°C or higher and 150°C or lower. When the component (B2) has the above boiling point, the component (B2) does not volatilize when the support film or copper foil is coated with the polyimide resin composition or the adhesive composition containing the composition. It is possible to prevent the occurrence of process irregularities and voids. In addition, since the coating layer of these compositions is easily volatilized when dried, the component (B2) does not remain in the resulting cured product layer, and as a result, low dielectric properties are also exhibited. Become. The upper limit and lower limit of the boiling point include 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, etc. . For the same reason as above, the boiling point of the component (B2) is more preferably 70°C or higher and 140°C or lower.

Among the preferred component (B2), ketones include, for example, methyl ethyl ketone (80° C.), methyl-n-propyl ketone (102° C.), methyl isopropyl ketone (93° C.), n-butyl methyl ketone (127° C.), isobutyl methyl ketone (116 ° C), sec-butyl methyl ketone (116 ° C), tert-butyl methyl ketone (106 ° C), diethyl ketone (101 ° C), ethyl-n-propyl ketone (123 ° C), ethyl isopropyl ketone (115 ° C.), n-butyl ethyl ketone (147° C.), ethyl isobutyl ketone (136° C.), tert-butyl ethyl ketone (125° C.), di-n-propyl ketone (145° C.), and other aliphatic ketones; cyclopropyl methyl ketone (114° C.), cyclobutanone (99° C.), cyclobutyl methyl ketone (138° C.), cyclopentanone (131° C.) and other alicyclic ketones. These may be used alone or in combination of two or more.

Among the preferred (B2) components, ethers include, for example, ethyl-n-propyl ether (62°C), di-n-propyl ether (90°C), isopropyl-n-propyl ether (83), diisopropyl ether (69°C ) and other aliphatic monoethers; 1,2-dimethoxyethane (85° C.), 1,1-diethoxyethane (103° C.), 1,2-diethoxyethane (121° C.), 1,2-dimethoxypropane ( 96° C.), 2,2-dimethoxypropane (80° C.), 1,1-diethoxypropane (123° C.), 2,2-diethoxypropane (113° C.); triethoxymethane (143° C.); ) and 1,1,1-trimethoxyethane (107° C.); alicyclic monoethers such as methoxycyclopentane (106° C.) and methoxycyclohexane (135° C.); These may be used alone or in combination of two or more.

Among preferred components (B2), aliphatic hydrocarbons include n-alkanes such as n-hexane (69°C), n-heptane (94°C), n-octane (126°C); ° C.), 3-ethylpentane (93° C.), 2-methylhexane (90° C.), 3-methylhexane (92° C.), 3-ethylhexane (118° C.), 2-methylheptane (116° C.), 3- Methylheptane (120°C), 4-methylheptane (117°C), 3-ethylheptane (143°C), 2-methyloctane (143°C), 3-methyloctane (144°C), 4-methyloctane (142°C) ), etc.; 2,2-dimethylpentane (79°C), 2,4-dimethylpentane (80°C), 2,2-dimethylhexane (106°C), 2,3-dimethylhexane (115°C) , 2,4-dimethylhexane (108°C), 2,5-dimethylhexane (108°C), 4-ethyl-2-methylhexane (134°C), 2,2-dimethylheptane (133°C), 2,3 -dimethylheptane (140°C), 2,4-dimethylheptane (133°C), 2,5-dimethylheptane (136°C), 3,3-dimethylheptane (137°C), 3,4-dimethylheptane (140°C) ) and other dialkylalkanes. These may be used alone or in combination of two or more.

Among preferred components (B2), alicyclic hydrocarbons include cycloalkanes such as cyclohexane (81°C) and cycloheptane (118°C); Pentane (103°C), n-propylcyclopentane (131°C), isopropylcyclopentane (126°C), isobutylcyclopentane (148°C), methylcyclohexane (101°C), ethylcyclohexane (132°C), methylcycloheptane ( monoalkylcycloalkanes such as 145°C); and dialkylcycloalkanes such as 1,1-dimethylcyclohexane (118°C) and 1-ethyl-3-methylcyclohexane (150°C). These may be used alone or in combination of two or more.

Among these (B2) components, ethers and alicyclic hydrocarbons are preferably contained from the viewpoint of good compatibility between the (A) component and the (B2) component.

The content ratio of the component (B1) and the component (B2) is, in the production of the component (A), the polyamic acid and the polyimide resin that are produced in the production of the component (A) can be well dissolved, and the by-product water can be removed. (B1)/(B2)=10/90 to 90/10 is preferred, 15/85 to 85/15 is more preferred, and 20/80 to 80/20 is even more preferred.

[Adhesive composition]
The adhesive composition of the present invention contains the polyimide resin composition of the present invention and a cross-linking agent.

The content of the polyimide resin composition in the adhesive composition of the present invention is not particularly limited, but is preferably about 10 to 99.5% by mass based on 100% by mass of the adhesive composition.

The content of component (A) in the adhesive composition of the present invention is not particularly limited, but is preferably about 2 to 98% by mass based on 100% by mass of non-volatile matter in the adhesive composition.

Various known cross-linking agents can be used without particular limitation as long as they function as cross-linking agents for polyimide. The cross-linking agents may be used alone or in combination of two or more. The cross-linking agent is preferably at least one selected from the group consisting of epoxides, benzoxazines, bismaleimides and cyanate esters.

Epoxides include phenol novolac type epoxide, cresol novolac type epoxide, bisphenol A type epoxide, bisphenol F type epoxide, bisphenol S type epoxide, hydrogenated bisphenol A type epoxide, hydrogenated bisphenol F type epoxide, stilbene type epoxide, and triazine skeleton-containing epoxide. , fluorene skeleton-containing epoxide, linear aliphatic epoxide, alicyclic epoxide, glycidylamine-type epoxide, triphenolmethane-type epoxide, alkyl-modified triphenolmethane-type epoxide, biphenyl-type epoxide, dicyclopentadiene skeleton-containing epoxide, naphthalene skeleton-containing Examples include epoxides, arylalkylene type epoxides, tetraglycidylxylylenediamine, dimer acid-modified epoxides which are dimer acid-modified epoxides, dimer acid diglycidyl esters, and the like. In addition, commercially available epoxides include "jER828", "jER834", "jER807", "jER604", and "jER630" manufactured by Mitsubishi Chemical Corporation, and "ST-3000" manufactured by Nippon Steel Chemical & Materials Co., Ltd. ”, “Celoxide 2021P” manufactured by Daicel Corporation, “YD-172-X75” manufactured by Nippon Steel Chemical & Materials Co., Ltd., “TETRAD-X” manufactured by Mitsubishi Gas Chemical Co., Ltd., and the like. Among these, at least one selected from the group consisting of bisphenol A type epoxide, bisphenol F type epoxide, hydrogenated bisphenol A type epoxide and alicyclic epoxide is preferable from the viewpoint of balance between solder heat resistance and low dielectric properties.

（式中、Ｚはフェニレン基又はシクロヘキシレン基を表す。）
は、前記ポリイミドとの相溶性が良好である。また、これを用いると接着剤層の低損失弾性率化が容易となり、そのはんだ耐熱性及び低誘電特性も良好となる。 In particular, tetraglycidyldiamine of general formula (3)

(In the formula, Z represents a phenylene group or a cyclohexylene group.)
has good compatibility with the polyimide. In addition, the use of this facilitates the reduction of the loss elastic modulus of the adhesive layer, and also improves the solder heat resistance and low dielectric properties.

When an epoxide is used as a cross-linking agent, various known epoxide curing agents and active ester curing agents can be used in combination. These curing agents may be used alone or in combination of two or more.

Epoxide curing agents include, for example, succinic anhydride, phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methyl-hexahydro Phthalic anhydride, or a mixture of 4-methylhexahydrophthalic anhydride and hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl-tetrahydrophthalic anhydride, nadic anhydride, methylnadic anhydride, norbornane-2,3-dicarboxylic acid Acid anhydride-based curing agents such as acid anhydride, methylnorbornane-2,3-dicarboxylic anhydride, methylcyclohexenedicarboxylic anhydride, 3-dodecenylsuccinic anhydride, and octenylsuccinic anhydride;
Dicyandiamide (DICY), aromatic diamines (trade names “Lonzacure M-DEA”, “Lonzacure M-DETDA”, etc., both manufactured by Lonza Japan Co., Ltd.), amine-based curing agents such as aliphatic amines;
Phenolic curing agents such as phenol novolak resin, cresol novolak resin, bisphenol A type novolak resin, triazine-modified phenol novolac resin, phenolic hydroxyl group-containing phosphazene (trade name "SPH-100" manufactured by Otsuka Chemical Co., Ltd., etc.);
Rosin-based curing agents such as maleic acid-modified rosin and hydrides thereof;
A cyclic phosphazene-based compound and the like can be mentioned.

Examples of active ester curing agents include those containing a dicyclopentadienyldiphenol structure, those containing a naphthalene structure, acetylated phenol novolacs, and benzoylated phenol novolacs described in JP-A-2019-183071. be done.
Examples of commercially available active ester curing agents include:
Those containing a dicyclopentadienyl diphenol structure, "EXB9451", "EXB9460", "EXB9460S", "HPC-8000", "HPC-8000H", "HPC-8000-65T", "HPC-8150- 62T", "HPC-8000H-65MT", "HPC-8000L-65MT", "EXB-8000L", "EXB-8000L-65MT", "EXB-8150-65T" (manufactured by DIC Corporation);
containing a naphthalene structure, "EXB9416-70BK" (manufactured by DIC Corporation);
An acetylated product of phenol novolak, "DC808" (manufactured by Mitsubishi Chemical Corporation);
Benzoylated phenol novolaks, such as "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation).

As the active ester curing agent, those produced by various known methods can also be used, and examples thereof include those obtained by reacting polyfunctional phenol compounds and aromatic carboxylic acids described in Japanese Patent No. 5,152,445. mentioned.

Among the curing agents, active ester curing agents, phenolic curing agents, and particularly active ester curing agents are preferred. Although the amount of the curing agent used is not particularly limited, it is preferably about 0.1 to 40% by mass, more preferably about 1 to 10% by mass, based on 100% by mass of the nonvolatile matter of the adhesive composition.

Moreover, when an epoxide and an epoxide curing agent are used together as a cross-linking agent, a reaction catalyst can be further used together. The reaction catalyst may be used alone or in combination of two or more. The reaction catalyst is a tertiary amine such as 1,8-diaza-bicyclo[5.4.0]undecene-7, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole and 2-heptadecylimidazole; organic compounds such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine and phenylphosphine; Phosphine; Tetraphenylboron salts such as tetraphenylphosphonium/tetraphenylborate, 2-ethyl-4-methylimidazole/tetraphenylborate, N-methylmorpholine/tetraphenylborate, and the like. The amount of the reaction catalyst to be used is not particularly limited, but is preferably about 0.01 to 5% by mass based on 100% by mass of the non-volatile matter of the adhesive composition.

Benzoxazines are 6,6-(1-methylethylidene)bis(3,4-dihydro-3-phenyl-2H-1,3-benzoxazine), 6,6-(1-methylethylidene)bis(3, 4-dihydro-3-methyl-2H-1,3-benzoxazine) and the like. A phenyl group, a methyl group, a cyclohexyl group, or the like may be bonded to the nitrogen of the oxazine ring. In addition, commercial products of benzoxazine include "Benzoxazine Fa type" and "Benzoxazine Pd type" manufactured by Shikoku Kasei Co., Ltd., and "RLV-100" manufactured by Air Water. mentioned.

Bismaleimides include 4,4′-diphenylmethanebismaleimide, m-phenylenebismaleimide, bisphenol A diphenylether bismaleimide, 3,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethanebismaleimide, 4- methyl-1,3-phenylenebismaleimide, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, 4,4'-diphenyletherbismaleimide, 4,4'-diphenylsulfonebismaleimide and the like. be done. Commercially available products of bismaleimide include “BAF-BMI” manufactured by JFE Chemical Co., Ltd., “BMI-1000H” manufactured by Daiwa Kasei Kogyo Co., Ltd., and the like.

Cyanate esters include 2-allylphenol cyanate ester, 4-methoxyphenol cyanate ester, 2,2-bis(4-isocyanatophenyl)-1,1,1,3,3,3-hexafluoropropane, bisphenol A cyanate ester, diallyl bisphenol A cyanate ester, 4-phenylphenol cyanate ester, 1,1,1-tris(4-cyanatophenyl) ethane, 4-cumylphenol cyanate ester, 1,1-bis(4-cyanatophenyl ) ethane, 4,4′-bisphenolcyanate ester, and 2,2-bis(4-cyanatophenyl)propane. Commercially available cyanate esters include "PRIMASET BTP-6020S" manufactured by Lonza Japan Co., Ltd., and the like.

The content of the cross-linking agent in the adhesive composition of the present invention is not particularly limited. The content of the cross-linking agent is preferably about 1 to 900 parts by mass with respect to 100 parts by mass (in terms of non-volatile content) of the component (A) of the present invention in the adhesive composition.

The content of the cross-linking agent in the adhesive composition of the present invention is preferably about 1 to 80% by mass based on 100% by mass of the non-volatile matter of the adhesive composition.

The adhesive composition of the present invention may contain a flame retardant. A flame retardant may be used alone or in combination of two or more. Examples of flame retardants include phosphorus-based flame retardants and inorganic fillers.

Phosphorus-based flame retardants include polyphosphoric acid, phosphate esters, phosphazene derivatives having no phenolic hydroxyl group, and the like. Among the phosphazene derivatives, cyclic phosphazene derivatives are preferred in terms of flame retardancy, heat resistance, bleed-out resistance and the like. Commercially available cyclic phosphazene derivatives include “SPB-100” manufactured by Otsuka Chemical Co., Ltd., “Ravitoll FP-300B” manufactured by Fushimi Pharmaceutical Co., Ltd., and the like.

Examples of inorganic fillers include silica fillers, phosphorus-based fillers, fluorine-based fillers, inorganic ion exchanger fillers, and the like. As for the silica filler, the surface thereof may be modified with a treating agent such as a silane coupling agent. In addition, commercially available inorganic fillers include “FB-3SDC” and “SFP-20M” manufactured by Denka Co., Ltd., “SC-2500-SPJ” and “SC-2500-SXJ” manufactured by Admatechs Co., Ltd. , “SC-2500-SVJ”, “Exolit OP935” manufactured by Clariant Chemicals Co., Ltd., “KTL-500F” manufactured by Kitamura Co., Ltd., “IXE” manufactured by Toagosei Co., Ltd., and the like.

The content of the flame retardant in the adhesive composition of the present invention is not particularly limited. The content of the flame retardant is preferably 1 to 150 parts by mass with respect to 100 parts by mass (on a non-volatile basis) of component (A) of the present invention in the adhesive composition.

The adhesive composition of the present invention has the general formula: W—Si(R ¹ ) _a (OR ² ) _3-a (wherein W represents a group containing a functional group that reacts with an acid anhydride group, R ¹ represents hydrogen or a hydrocarbon group having 1 to 8 carbon atoms, R ² represents a hydrocarbon group having 1 to 8 carbon atoms, and a represents 0, 1 or 2.) But it's okay. The reactive alkoxysilyl compound allows the melt viscosity of the adhesive layer of the adhesive composition of the present invention to be adjusted while maintaining low dielectric properties. As a result, the bleeding of the hardened layer from the edge of the support can be suppressed while increasing the interfacial adhesive strength (so-called anchor effect) between the adhesive layer and the support.

Examples of the reactive functional group included in W in the general formula include an amino group, an epoxy group and a thiol group.

Compounds in which W contains an amino group include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, and 3-aminopropyltrimethoxysilane. , 3-aminopropyltriethoxysilane and 3-ureidopropyltrialkoxysilane. Examples of compounds in which W contains an epoxy group include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, Examples include sidoxypropylmethyldiethoxysilane and 3-glycidoxypropyltriethoxysilane. Examples of compounds in which W contains a thiol group include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropylmethyldiethoxysilane. Among these, a compound in which W contains an amino group is preferable because of good reactivity and flow control effect.

The content of the reactive alkoxysilyl compound in the adhesive composition of the present invention is not particularly limited. The content of the reactive alkoxysilyl compound is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass (on a non-volatile basis) of component (A) of the present invention in the adhesive composition.

The adhesive composition of the present invention may contain an additive other than the polyimide resin composition of the present invention, a cross-linking agent, a flame retardant, a reactive alkoxysilyl compound, or the above organic solvent.

Additives include ring-opening esterification reaction catalysts, dehydrating agents, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, brighteners, coloring agents, conductive agents, release agents, and surface treatment. agents, viscosity modifiers, silica fillers and fluorine fillers.

The content of the additive is not particularly limited, but is less than 1 part by mass, less than 0.1 part by mass, less than 0.01 part by mass, 0 part by mass, etc. with respect to 100 parts by mass of the non-volatile matter of the adhesive composition. is mentioned.

The content of the additive is not particularly limited. , 0 parts by mass, and the like.

The adhesive composition of the present invention is obtained by dissolving the crosslinking agent and, if necessary, the flame retardant, reactive alkoxysilyl compound and additives in the polyimide resin composition of the present invention. In addition, in the preparation of the adhesive composition, the aforementioned component (B) may be further blended.

[Film adhesive]
The film adhesive of the present invention contains a cured product of the adhesive composition of the present invention. A method for producing a film adhesive includes a step of applying the adhesive composition to a suitable support, a step of curing by heating to volatilize the organic solvent, a step of peeling off the support, and the like. methods and the like. Also, the thickness of the adhesive is not particularly limited, but is preferably about 3 to 40 μm. Examples of the support include release paper, release film, support film described later, and the like. Moreover, when manufacturing the said film-like adhesive material, you may use together the said adhesive composition and various well-known adhesive compositions other than the said adhesive.

[Adhesive sheet]
The adhesive sheet of the present invention contains the film adhesive of the present invention on at least one side of a support film.

The adhesive sheet is obtained, for example, by coating the adhesive composition of the present invention on a support film and curing by heating, or by laminating the film adhesive of the present invention on a support film. .

The support film includes polyimide, polyester, polyimide-silica hybrid, polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polymethyl methacrylate resin, polystyrene resin, polycarbonate resin, acrylonitrile-butadiene-styrene resin, ethylene terephthalate, phenol, phthalate. Aromatic polyester resin obtained from acid, hydroxynaphthoic acid, etc. and parahydroxybenzoic acid (so-called liquid crystal polymer; Kuraray Co., Ltd., "Vecstar" etc.), cycloolefin polymer, fluorine resin (polytetrafluoroethylene ( PTFE), perfluoroalkoxyalkane (PFA), polyvinylidene fluoride (PVDF), etc.). Polyimide includes the polyimide film of the present invention.

When the adhesive composition of the present invention is applied to the support film, the method of application is not particularly limited, and examples thereof include using a coater such as a comma, die, knife, and lip coater. The thickness of the coating layer is also not particularly limited, but the thickness after drying is preferably about 1 to 100 μm, more preferably about 3 to 50 μm. Moreover, the adhesive layer of the adhesive sheet may be protected with various protective films.

[Resin coated copper foil]
The resin-coated copper foil of the present invention includes the film adhesive and copper foil of the present invention. Specifically, the adhesive composition of the present invention is applied to a copper foil and cured by heating, or the film-like adhesive of the present invention is attached to a copper foil. Examples of the copper foil include rolled copper foil and electrolytic copper foil, and those subjected to various surface treatments (roughening, rust prevention, etc.) can also be used. Examples of the anti-rust treatment include plating using a plating solution containing Ni, Zn, Sn, etc., and so-called mirror surface treatment such as chromate treatment.

The thickness of the copper foil is also not particularly limited, preferably about 1 to 100 μm, more preferably about 2 to 38 μm. Moreover, an above-described method is mentioned as a coating means.

The adhesive layer or film-like adhesive of the resin-coated copper foil may be uncured, or may be partially cured or completely cured under heating. A partially cured adhesive layer or film adhesive is in a so-called B-stage state. Also, the thickness of the adhesive layer or film adhesive is not particularly limited, and is preferably about 0.5 to 30 μm. Further, resin can be further bonded to the copper foil of the resin-coated copper foil to form a resin-coated copper foil on both sides.

[Copper clad laminate]
The copper-clad laminate of the present invention includes the resin-coated copper foil, copper foil, or insulating sheet of the present invention. A copper clad laminate is also called CCL (Copper Clad Laminate). Specifically, the copper-clad laminate is obtained by press-bonding the resin-coated copper foil to at least one side or both sides of various known copper foils or insulating sheets under heating. In the case of lamination on one side, a material different from the resin-coated copper foil may be pressure-bonded to the other side. Further, the number of resin-coated copper foils, copper foils and insulating sheets in the copper-clad laminate is not particularly limited.

In one embodiment, the insulating sheet is preferably a prepreg or the aforementioned support film. A prepreg is a sheet-shaped material obtained by impregnating a reinforcing material such as a glass cloth with a resin and curing it to the B stage (JIS C 5603). Insulating resins such as the component (A) of the present invention, phenolic resins, epoxy resins, polyester resins, liquid crystal polymers and aramid resins are used as the resin. The thickness of the insulating sheet is not particularly limited, and is preferably about 20 to 500 μm. The heating/pressing conditions are not particularly limited, and are preferably about 150 to 280° C. (more preferably about 170 to 240° C.) and preferably about 0.5 to 20 MPa (more preferably about 1 to 8 MPa).

[Printed wiring board]
The printed wiring board of the present invention has a circuit pattern on the copper foil surface of the copper-clad laminate of the present invention. Patterning means for forming a circuit pattern on the copper foil surface of a copper-clad laminate include a subtractive method and a semi-additive method. The semi-additive method includes a method of patterning the copper foil surface of the copper-clad laminate with a resist film, performing electrolytic copper plating, removing the resist, and etching with an alkaline solution. Moreover, the thickness of the circuit pattern layer in the printed wiring board is not particularly limited. A multilayer board can also be obtained by using the printed wiring board as a core and laminating the same printed wiring board or other known printed wiring board or printed circuit board thereon. At the time of lamination, the above-mentioned adhesive composition and other known adhesive compositions other than the above-mentioned adhesive composition can be used together. Also, the number of laminations in the multilayer substrate is not particularly limited. Also, each time lamination is performed, a via hole may be inserted and the inside thereof may be plated. Although the line/space ratio of the circuit pattern is not particularly limited, it is preferably about 1 μm/1 μm to 100 μm/100 μm. Also, the height of the circuit pattern is not particularly limited, but is preferably about 1 to 50 μm.

[Polyimide film]
The polyimide film of the present invention is a cured product of the polyimide resin composition of the present invention.

As a method for producing the polyimide film of the present invention, the polyimide resin composition is coated on the above-described support, cured by heating to form a polyimide resin layer, and the support is peeled off from the polyimide resin layer. etc.

The method for coating the polyimide resin composition on the support is not particularly limited, and the coating means described above can be used. The heat treatment conditions are also not particularly limited, and examples thereof include a method of heating at a temperature of about 100 to 180° C. for about 0.5 to 3 hours.

The thickness of the polyimide resin layer after heat treatment is not particularly limited, but the thickness after drying is preferably about 1 to 50 μm.

The polyimide resin composition used for the polyimide film of the present invention may contain various additives as long as the effects of the present invention are not impaired. The additives include dehydrating agents, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, brighteners, coloring agents, conductive agents, release agents, surface treatment agents, viscosity modifiers, Examples include inorganic fillers, inorganic pigments, and organic pigments.

Examples of inorganic fillers include silica fillers, phosphorus-based fillers, fluorine-based fillers, inorganic ion exchanger fillers, and the like. As for the silica filler, the surface thereof may be modified with a treating agent such as a silane coupling agent. In addition, commercially available inorganic fillers include “FB-3SDC” and “SFP-20M” manufactured by Denka Co., Ltd., “SC-2500-SPJ” and “SC-2500-SXJ” manufactured by Admatechs Co., Ltd. , “SC-2500-SVJ”, “Exolit OP935” manufactured by Clariant Chemicals Co., Ltd., “KTL-500F” manufactured by Kitamura Co., Ltd., IXE manufactured by Toagosei Co., Ltd., and the like.

Examples of inorganic pigments include cadmium red, cadmium lemon yellow, cadmium yellow orange, titanium dioxide, carbon black, black iron oxide, and black complex inorganic pigments.

Examples of organic pigments include aniline black, perylene black, anthraquinone black, benzidine yellow pigments, phthalocyanine blue and phthalocyanine green.

The content of the additive in the polyimide resin composition of the present invention is not particularly limited, but is preferably 1 to 150 parts by mass with respect to 100 parts by mass of component (A) (on a non-volatile basis basis).

The present invention will be specifically described below with reference to Examples, but the present invention is not particularly limited to these. All "%" are based on mass unless otherwise specified.

Example 1
4,4'-[Propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic dianhydride (product name "BisDA-1000", manufactured by SABIC Innovative Plastics Japan LLC., hereinafter abbreviated as BisDA), 200.0 g of diethyl carbonate, 619.0 g of 1,2-dimethoxyethane, 132.6 g of methylcyclohexane and 132 g of methylcyclohexane. Charge 0.6 g and heat to 75°C. Next, after gradually adding 197.8 g of dimer diamine (trade name “PRIAMINE 1075”, manufactured by Croda Japan Co., Ltd., hereinafter referred to as PRIAMINE 1075), the mixture is heated to 115° C. and imidization reaction is carried out over 10 hours. Thus, a polyimide solution (30% non-volatile content) was obtained. The obtained solution was used as a polyimide resin composition. (same below)

Examples 2-18, Comparative Example 1
A polyimide resin having a non-volatile content of 30% was obtained in the same manner as in Example 1 except that the composition and amount used were changed to those shown in Table 1.

Comparative Examples 2 and 3
The type of solvent was changed to one shown in Table 1, and the procedure was carried out in the same manner as in Example 1, but the polyamic acid produced did not dissolve, and no polyimide was obtained.

<Preparation of evaluation sample>
The polyimide resin compositions of Examples 1 to 18 and Comparative Example 1 were coated on release paper (manufactured by San A Kaken Co., Ltd.), dried at 150° C. for 5 minutes, and then dried at 170° C. for 30 minutes. The release paper was peeled off to obtain a polyimide film having a thickness of 25 μm. Two sheets of the film were laminated and melted by a hot press at 120° C. to prepare an evaluation sample.

<Relative permittivity and dielectric loss tangent>
Using a network analyzer (manufactured by Keysight Technologies, device name: "P5003A") and a split post dielectric resonator (manufactured by QWED) with a measurement frequency of 10.124 GHz, the resonance frequency of a single resonator with nothing inserted and The Q value of the peak was measured.
Next, after cutting the evaluation sample into a size of 4 cm × 5 cm to prepare a test piece, a plurality of test pieces are overlapped so that the total thickness is 100 μm or more, and inserted into the resonator. The resonance frequency and Q value were measured when the piece was inserted.
The dielectric constant (Dk) is calculated from the difference in resonance frequency between the resonator alone and the test piece inserted. It was calculated from the difference in resonance frequency. Table 1 shows the results.

Abbreviations in Table 1 are as follows.
<Aromatic tetracarboxylic anhydride>
(a1) Component BisDA: 4,4'-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic dianhydride, trade name: "BisDA-1000", SABIC Innovative Plastics Japan Joint Company manufactured 6FDA: 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, manufactured by Daikin <diamine>
(a2) component DDA: dimer diamine, trade name: "PRIAMINE 1075", manufactured by Croda Japan Co., Ltd. ODA: 4,4'-diaminophenyl ether, manufactured by Wakayama Seika Kogyo Co., Ltd. <organic solvent>
(B1) component DEC: diethyl carbonate (boiling point: 126 ° C.)
・ AcOBu: n-butyl acetate (boiling point: 126 ° C.)
(B2) Component DMG: 1,2-dimethoxyethane (boiling point: 82°C)
・MEK: methyl ethyl ketone (boiling point: 80°C)
・MIBK: methyl isobutyl ketone (boiling point: 116°C)
・MCH: methylcyclohexane (boiling point: 101° C.)
・ OCT: n-octane (boiling point: 126 ° C.)
・ C-800: 2-methylheptane (boiling point: 116 ° C., trade name: “Kyowasol C-800”, manufactured by KH Neochem Co., Ltd.)
(Other solvents)
・DMAc: N,N-dimethylacetamide (boiling point: 165 ° C.)

<Preparation of adhesive composition>
Evaluation example 1
100.0 g of the polyimide resin composition of Example 1 (non-volatile content 30.0 g), as a cross-linking agent, polyfunctional epoxy resin (trade name: "TETRAD-X", manufactured by Mitsubishi Gas Chemical Co., Ltd.) 0.78 g (non-volatile 0.78 g per minute), as a curing agent, an active ester resin (trade name: "EPICLON HPC-8000-65T", manufactured by DIC Corporation) 2.67 g (nonvolatile content 1.75 g) and an imidazole epoxy resin (trade name : "Cure Sol 2E4MZ-A", manufactured by Shikoku Kasei Co., Ltd.) 0.008 g (nonvolatile content 0.008 g), as an inorganic filler, silica (trade name: "SC-2500-SPJ", manufactured by Admatechs Co., Ltd. ) (32.5 g of non-volatile content) and 62.1 g of cyclopentanone as an organic solvent were mixed and thoroughly stirred to obtain an adhesive composition having a non-volatile content of 33%.

Evaluation Examples 2 to 4, Comparative Evaluation Example 1
Using each of the polyimide resin compositions shown in Table 2, the same method as in Evaluation Example 1 was used to obtain an adhesive composition having a non-volatile content of 33%.

<Preparation of adhesive sheet>
The resulting adhesive composition was applied to a release paper (manufactured by San A Kaken Co., Ltd.) with a gap coater so that the thickness after drying was 25 μm, and then dried at 150° C. for 5 minutes to form an adhesive sheet ( Release paper/adhesive layer) was obtained.

<Measurement of dielectric constant and dielectric loss tangent>
The release paper is peeled off from the adhesive sheet (release paper/adhesive layer), the adhesive layer is placed on a support for pressing, and the same support for pressing is placed on the side of the adhesive layer, and the pressure is 5 MPa. By curing with a hot press at 180° C. for 90 minutes, an adhesive sheet (support/adhesive layer/support) after thermal curing was produced. The support for pressing was removed from the adhesive sheet, and the dielectric constant (Dk) and dielectric loss tangent (Df) of the adhesive layer were calculated in the same manner as in the previous paragraph. Table 2 shows the results.

<Preparation of copper-clad laminate>
Peel off the release paper from the adhesive sheet (release paper/adhesive layer), and put it on the mirror surface side of commercially available electrolytic copper foil (product name “F2-WS”, manufactured by Furukawa Electric Co., Ltd.) (thickness 18 μm). , The other surface is laminated on a commercially available polyimide film (trade name “Kapton 100EN”, manufactured by Toray DuPont Co., Ltd.; film thickness 25 μm; thermal expansion coefficient; 15 ppm / ° C.), polyimide film-adhesive layer-electrolysis A copper foil laminate was produced. Next, it was placed on a support for pressing, and cured by a heat press at a pressure of 5 MPa and a temperature of 180° C. for 90 minutes through a support made of the same material from above to produce a copper-clad laminate.

<Adhesion test>
The peel strength (N/mm) of the copper-clad laminate was measured according to JIS C 6481 (testing method for copper-clad laminate for flexible printed wiring boards). Table 2 shows the results.

<Solder heat resistance test>
After leaving the copper-clad laminate in a temperature-controlled room at a temperature of 23° C. and a humidity of 50% for 24 hours, it is floated in a solder bath at 288° C. with the copper foil side down, and the presence or absence of foaming is confirmed. evaluated with Table 2 shows the results.
(Evaluation criteria)
○: No change in appearance ×: Foaming and blistering

Claims (12)

A polyimide resin composition containing a polyimide (A) which is a reactant of a monomer group containing an aromatic tetracarboxylic anhydride (a1) and a diamine (a2) containing a dimer diamine, and two or more different organic solvents (B) being a thing,
Component (B) is a polyimide resin composition containing an ester (B1) and at least one organic solvent (B2) selected from the group consisting of ketones, ethers, aliphatic hydrocarbons and alicyclic hydrocarbons. 2. The polyimide resin composition according to claim 1, wherein the component (a2) further contains an alicyclic diamine and/or an aromatic diamine. The polyimide resin composition according to claim 1 or 2, wherein the content ratio of the component (B1) and the component (B2) is (B1)/(B2) = 10/90 to 90/10 in mass ratio. The polyimide resin composition according to any one of claims 1 to 3, wherein the component (B) does not contain an aromatic hydrocarbon. 5. The polyimide resin composition according to any one of claims 1 to 4, wherein component (B1) is an aliphatic ester. An adhesive composition comprising the polyimide resin composition according to any one of claims 1 to 5 and a cross-linking agent. A film adhesive comprising a cured product of the adhesive composition according to claim 6 . An adhesive sheet having the film adhesive according to claim 7 on at least one side of a support film. A resin-coated copper foil comprising the film adhesive according to claim 7 and a copper foil. A copper-clad laminate comprising the resin-coated copper foil according to claim 9 and a copper foil or an insulating sheet. A printed wiring board having a circuit pattern on the copper foil surface of the copper-clad laminate according to claim 10 . A polyimide film, which is a cured product of the polyimide resin composition according to any one of claims 1 to 5.