Polyimide resin composition, adhesive composition, and related articles thereof

Abstract

[Technical Problem] To provide a polyimide resin composition in which, even without using an organic solvent containing a nitrogen atom and an aromatic hydrocarbon, the organic solvent is easily volatilized during drying under heating, and to provide a polyimide resin layer having a low dielectric constant, a low dielectric loss tangent, and excellent soldering heat resistance. [Technical Means] A polyimide resin composition comprising a polyimide (A) and two or more different organic solvents (B), wherein the polyimide (A) is a reaction product of a monomer group comprising an aromatic tetracarboxylic dianhydride (a1) and a diamine (a2) containing a dimer diamine; and the component (B) comprises 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.

Description

Technical Field

[0001] The present invention relates to a polyimide resin composition, an adhesive composition, a film-like adhesive material, an adhesive sheet, a resin-coated copper foil, a copper-clad laminate, a printed wiring board, and a polyimide film. Background Art

[0002] Flexible printed wiring boards (FPWBs), printed circuit boards (PCBs), and multi-layer wiring boards using them are widely used in mobile communication devices such as mobile phones and smartphones, their base station devices, network-related electronic devices such as servers and routers, and products such as mainframe computers.

[0003] In addition, in recent years, in these products, in order to transmit and process a large amount of information at high speed, high-frequency electric signals are used. However, high-frequency signals are very prone to attenuation, so a method for minimizing transmission loss on the above multi-layer wiring board is sought.

[0004] As a means for suppressing transmission loss in a multi-layer wiring board, for example, when laminating a printed wiring board or a printed circuit board, a polyimide resin is considered as an adhesive composition having characteristics of both a small dielectric constant and a small dielectric loss tangent (hereinafter also referred to as a low dielectric property).

[0005] As such a polyimide, a resin having a tetracarboxylic acid residue and a diamine residue derived from a dimer acid, which is known to form an adhesive layer in a metal-clad laminate having an insulating resin layer, an adhesive layer, and a metal layer (Patent Document 1), is known. Since this polyimide has an aromatic ring, it exhibits excellent solder heat resistance.

[0006] In addition, in the manufacture of FPWBs and the like, on a support such as polyethylene terephthalate (release PET) and release paper, although a step of applying an adhesive composition and drying it under heating is performed, since such a support lacks heat resistance, its drying is usually performed at a temperature of 150°C or lower. On this premise, when manufacturing the polyimide of Patent Document 1, N-methylpyrrolidone (NMP) and xylene are used as organic solvents. However, an organic solvent containing a nitrogen atom such as NMP has a high boiling point and is likely to remain when drying the resin composition at the aforementioned temperature, and is likely to have an adverse effect on the low dielectric property and solder heat resistance of the polyimide resin layer. In addition, an aromatic hydrocarbon such as xylene is harmful to the human body and the environment, and thus is not preferred for use.

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-140544 Summary of the Invention

[0010] Technical Problem to be Solved by the Invention

[0011] The present invention provides a polyimide resin composition in which, even without using an organic solvent containing a nitrogen atom and an aromatic hydrocarbon, the organic solvent easily volatilizes during drying under heating, and further provides a polyimide resin layer having a low dielectric constant, a low dielectric loss tangent, and excellent soldering heat resistance.

[0012] Technical Means for Solving the Technical Problem

[0013] The inventors of the present invention conducted in-depth research to solve the above problems and found that the above problems were solved in a specific combination of organic solvents, thereby completing the present invention. That is, in the present invention, the following is provided.

[0014] 1. A polyimide resin composition comprising polyimide (A) and two or more different organic solvents (B),

[0015] wherein the polyimide (A) is a reaction product of a monomer group containing an aromatic tetracarboxylic dianhydride (a1) and a diamine (a2) containing a dimer diamine;

[0016] The component (B) comprises 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.

[0017] 2. The polyimide resin composition according to item 1 above, wherein the component (a2) further comprises an alicyclic diamine and / or an aromatic diamine.

[0018] 3. The polyimide resin composition according to item 1 or 2 above, wherein, by mass ratio, the content ratio of the component (B1) and the component (B2) is (B1) / (B2) = 10 / 90 to 90 / 10.

[0019] 4. The polyimide resin composition according to any one of items 1 to 3 above, wherein the component (B) does not contain an aromatic hydrocarbon.

[0020] 5. The polyimide resin composition according to any one of items 1 to 4 above, wherein the component (B1) is an aliphatic ester.

[0021] 6. An adhesive composition comprising the polyimide resin composition according to any one of items 1 to 5 above and a crosslinking agent.

[0022] 7. A film adhesive material, wherein the film adhesive material comprises a cured product of the adhesive composition described in the preceding item 6.

[0023] 8. An adhesive sheet, wherein the adhesive sheet has the film adhesive material described in the preceding item 7 on at least one surface of a support film.

[0024] 9. A resin-coated copper foil, wherein the resin-coated copper foil comprises the film adhesive material described in the preceding item 7 and a copper foil.

[0025] 10. A copper-clad laminate, wherein the copper-clad laminate comprises the resin-coated copper foil described in the preceding item 9 and a copper foil or an insulating sheet.

[0026] 11. A printed wiring board, wherein the printed wiring board has a circuit pattern on the copper foil surface of the copper-clad laminate described in the preceding item 10.

[0027] 12. A polyimide film, wherein the polyimide film is a cured product of the polyimide resin composition described in any one of the preceding items 1 to 5.

[0028] Advantageous Effects

[0029] According to the polyimide resin composition of the present invention, even without using an organic solvent containing a nitrogen atom and an aromatic hydrocarbon, in the drying under heating of the polyimide resin composition, the organic solvent is easily volatilized, and a polyimide resin layer having a low dielectric constant, a low dielectric loss tangent, and excellent heat resistance to soldering is provided. Detailed Embodiments

[0030] The polyimide resin composition of the present invention comprises polyimide (A) (hereinafter referred to as component (A)), and the polyimide (A) is a reaction product of a monomer group comprising aromatic tetracarboxylic dianhydride (a1) (hereinafter referred to as component (a1)) and diamine (a2) containing a dimer diamine (hereinafter referred to as component (a2)).

[0031] The component (a1) is not particularly limited. For example, 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 dianhydride, 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'-diphenylethertetracarboxylic 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 dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 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 dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 2,2-bis(3,3',4,4'-tetracarboxyphenyl)tetrafluoropropane dianhydride, etc. These can be used alone or in combination of two or more.

[0032] Among them, as the component (a1), from the viewpoints of the flexibility and soldering heat resistance of the polyimide resin layer, the compound represented by the following general formula (1) is preferred.

[0033] [Chemical formula 1]

[0034]

[0035] (In formula (1), X represents a single bond, -SO2-, -CO-, -O-, -O-C6H4-C(CH3)2-C6H4-O-, -C(CH3)2-, -O-C6H4-SO2-C6H4-O-, -C(CHF2)2-, -C(CF3)2-, -COO-(CH2) p -OCO- or -COO-H2C-HC(-O-C(=O)-CH3)-CH2-OCO-, and p represents an integer of 1 to 20.)

[0036] As the compound represented by the general formula (1), for example, 2,2’,3,3’-biphenyltetracarboxylic dianhydride, 3,3’,4,4’-biphenyltetracarboxylic dianhydride, 3,3’,4,4’-diphenylsulfone tetracarboxylic dianhydride, 3,3’,4,4’-benzophenone tetracarboxylic dianhydride, 3,3’,4,4’-diphenylether tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 2,2-bis(3,3’,4,4’-tetracarboxyphenyl)tetrafluoropropane dianhydride, 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, etc. are cited. These can be used alone or in combination of two or more. Among them, from the viewpoint of good solubility of the component (A) in an organic solvent, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride and 4,4’-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic dianhydride are preferred.

[0037] In 100 mol% of the monomer group constituting the component (A), the usage amount of the component (a1) is not particularly limited, and is usually 10 mol% to 90 mol%, preferably 25 mol% to 75 mol%.

[0038] In addition, in 100 mol% of the monomer group constituting the component (A), the usage amount of the tetracarboxylic dianhydride represented by the general formula (1) is not particularly limited, and is usually 10 mol% to 90 mol%, preferably 25 mol% to 75 mol%.

[0039] In 100 mol% of the component (a1), the usage amount of the tetracarboxylic dianhydride represented by the general formula (1) is not particularly limited, and is usually 10 mol% to 100 mol%, preferably 50 mol% to 100 mol%.

[0040] (The component (a2) is a diamine containing a dimer diamine.

[0041] The dimer diamine refers to a substance obtained by replacing all carboxyl groups of a dimer acid with primary amino groups or primary aminomethyl groups (for example, see Japanese Patent Laid-Open No. 9-12712). Here, the dimer acid mainly contains a dibasic acid (dicarboxylic acid) having 36 carbon atoms obtained by dimerizing unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid, and depending on its purification degree, contains monomer acids having 18 carbon atoms, trimer acids having 54 carbon atoms, and polymer fatty acids having 20 to 90 carbon atoms. In addition, the above dimer acid contains double bonds, but for example, the degree of unsaturation can be reduced by a hydrogenation reaction.

[0042] The above dimer diamine is not particularly limited, and examples thereof include substances represented by the following general formula (2). It should be noted that in the general formula (2), preferably m + n = 6 to 17, preferably p + q = 8 to 19, and the dotted line portion means a carbon-carbon single bond or a carbon-carbon double bond.

[0043] [Chemical formula 2]

[0044]

[0045] In addition, as commercially available products of dimer diamine, "Versamine 551", "Versamine 552" (manufactured by Cognis Japan Co., Ltd.), "PRIAMINE 1073", "PRIAMINE 1074", "PRIAMINE 1075" (manufactured by Croda Japan Co., Ltd.), etc. are cited.

[0046] In addition, the dimer diamine can be used directly, or a dimer diamine that has been purified by distillation or the like can be used.

[0047] In 100 mol% of the monomer group constituting the component (A), the amount of the dimer diamine used is not particularly limited, and is usually 5 mol% or more, preferably 25 mol% to 75 mol%.

[0048] In addition, in 100 mol% of the component (a2), the amount of the dimer diamine used is not particularly limited, and is usually 10 mol% or more, preferably 30 mol% to 100 mol%.

[0049] In addition, as the component (a2), a diamine (a2-1) other than the dimer diamine (hereinafter referred to as the component (a2-1)) may also be included. As the component (a2-1), for example, an aliphatic diamine, an alicyclic diamine, an aromatic diamine, a diamino ether, or a diamino polysiloxane may be included. In addition, for these amines, the dimer diamine is removed.

[0050] Examples of the aliphatic diamine include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, etc.

[0051] As alicyclic diamines, examples include 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, etc.

[0052] As aromatic diamines, examples include:

[0053] Diaminobiphenyls such as 2,2'-diaminobiphenyl, 3,3'-diaminobiphenyl, 4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 2,2'-dipropyl-4,4'-diaminobiphenyl, etc.;

[0054] Bis(aminophenoxyphenyl)propanes such as 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, etc.;

[0055] Diaminodiphenyl ethers such as 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, etc.;

[0056] Phenylenediamines such as p-phenylenediamine, m-phenylenediamine, etc.;

[0057] Diaminodiphenyl sulfides such as 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, etc.;

[0058] Diaminodiphenyl sulfones such as 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, etc.;

[0059] Diaminobenzophenones such as 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, etc.;

[0060] Diaminodiphenyl methanes such as 3,3'-diaminodiphenyl methane, 3,4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl methane, bis[4-(3-aminophenoxy)phenyl]methane, etc.;

[0061] Diaminophenylpropanes such as 2,2-bis(3-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, etc.;

[0062] 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2-(3-aminophenyl)-2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane and other diaminophenylhexafluoropropanes;

[0063] 1,1-bis(3-aminophenyl)-1-phenylethane, 1,1-bis(4-aminophenyl)-1-phenylethane, 1-(3-aminophenyl)-1-(4-aminophenyl)-1-phenylethane and other diaminophenylphenylethanes;

[0064] 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene and other bisaminophenoxybenzenes;

[0065] 1,3-bis(3-aminobenzoyl)benzene, 1,3-bis(4-aminobenzoyl)benzene, 1,4-bis(3-aminobenzoyl)benzene, 1,4-bis(4-aminobenzoyl)benzene and other bisaminobenzoylbenzenes;

[0066] 1,3-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene and other bisaminodimethylbenzylbenzenes;

[0067] 1,3-bis(3-amino-α,α-bistrifluoromethylbenzyl)benzene, 1,3-bis(4-amino-α,α-bistrifluoromethylbenzyl)benzene, 1,4-bis(3-amino-α,α-bistrifluoromethylbenzyl)benzene, 1,4-bis(4-amino-α,α-bistrifluoromethylbenzyl)benzene and other bisaminobistrifluoromethylbenzylbenzenes;

[0068] 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, bis[1-(3-aminophenoxy)]biphenyl and other aminophenoxybiphenyls;

[0069] bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone and other aminophenoxyphenylketones;

[0070] bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide and other aminophenoxyphenylsulfides;

[0071] bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone and other aminophenoxyphenylsulfones;

[0072] Aminophenoxyphenyl ethers such as bis[4-(3-aminophenoxy)phenyl] ether and bis[4-(4-aminophenoxy)phenyl] ether;

[0073] Aminophenoxyphenylpropane such as 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, and 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane;

[0074] Bis(aminophenoxybenzoyl)benzenes such as 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, and 1,4-bis[4-(4-aminophenoxy)benzoyl]benzene;

[0075] Bis(aminophenoxy-α,α-dimethylbenzyl)benzenes such as 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, and 1,4-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene;

[0076] Bis[(aminoaryloxy)benzoyl]diphenyl ethers such as 4,4'-bis[4-(4-aminophenoxy)benzoyl]diphenyl ether;

[0077] Bis(amino-α,α-dimethylbenzylphenoxy)benzophenones such as 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone;

[0078] Bis[amino-α,α-dimethylbenzylphenoxy]diphenyl sulfones such as 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl sulfone;

[0079] Bis[aminophenoxyphenoxy]diphenyl sulfones such as 4,4'-bis[4-(4-aminophenoxy)phenoxy]diphenyl sulfone;

[0080] Diaminodiaryloxybenzophenones such as 3,3'-diamino-4,4'-diphenoxydibenzophenone and 3,3'-diamino-4,4'-dibiphenoxydibenzophenone;

[0081] Diaminoaryloxybenzophenones such as 3,3'-diamino-4-phenoxydibenzophenone and 3,3'-diamino-4-biphenoxydibenzophenone;

[0082] 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine, 9,9-bis(4-aminophenyl)fluorene, etc.

[0083] As the diamino ether, for example, 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-aminopropoxy)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, etc.

[0084] As the diamino polysiloxane, for example, α,ω-bis(2-aminoethyl)polydimethylsiloxane, α,ω-bis(3-aminopropyl)polydimethylsiloxane, α,ω-bis(4-aminobutyl)polydimethylsiloxane, α,ω-bis(5-aminopentyl)polydimethylsiloxane, α,ω-bis[3-(2-aminophenyl)propyl]polydimethylsiloxane, α,ω-bis[3-(4-aminophenyl)propyl]polydimethylsiloxane, etc.

[0085] These (a2-1) components can be used alone or in combination of two or more. Among them, from the viewpoint of the polyimide resin layer showing excellent heat resistance to soldering, alicyclic diamines and aromatic diamines are preferred, and aromatic diamines are more preferred.

[0086] In 100 mol% of the monomer group constituting the component (A), the usage amount of the (a2-1) component is not particularly limited, and is usually 90 mol% or less, preferably 50 mol% or less.

[0087] In addition, in 100 mol% of the component (a2), the usage amount of the (a2-1) component is not particularly limited, and is usually 90 mol% or less, preferably 70 mol% or less.

[0088] Component (A) of the present invention can be obtained by various known manufacturing methods. As its manufacturing method, for example, a method including the following steps can be cited: a step of subjecting a monomer group containing component (a1) and component (a2) to a polyaddition reaction (polycondensation reaction) at a temperature preferably around 30°C to 120°C, more preferably around 40°C to 100°C, and for a time preferably around 0.1 hour to 2 hours, more preferably around 0.1 hour to 0.5 hour to obtain a polyaddition product (polycondensate); a step of subjecting the obtained polyaddition product to an imidization reaction (i.e., dehydration ring closure reaction) at a temperature preferably around 80°C to 250°C, more preferably around 80°C to 170°C for about 0.5 hour to 50 hours, more preferably 1 hour to 20 hours. In addition, the mixing method, order, etc. of component (a1) and component (a2) are not particularly limited.

[0089] In addition, in the step of performing the imidization reaction, various known reaction catalysts, dehydrating agents, and the organic solvent (B) described later can be used; they can be used alone or in combination of two or more.

[0090] Examples of the reaction catalyst include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, and heterocyclic tertiary amines such as pyridine, methylpyridine, and isoquinoline. In addition, examples of the dehydrating agent include aliphatic carboxylic anhydrides such as acetic anhydride and aromatic carboxylic anhydrides such as benzoic anhydride.

[0091] When using the organic solvent (B) described later in the production of component (A), its usage amount is adjusted so that the reaction concentration is 5% by mass to 60% by mass, preferably 20% by mass to 50% by mass.

[0092] The imide ring closure rate of component (A) is not particularly limited. From the viewpoint of obtaining component (A) with both a high softening point and flexibility, it is preferably 90% to 100%, more preferably around 95% to 100%.

[0093] By making the imide ring closure rate of component (A) within the above range, it is presumed that component (A) easily forms a structure of hard segments and soft segments, and both the softening point and flexibility will increase. Here, the "imide ring closure rate" refers to the content of cyclic imide bonds in the polyimide resin of component (A), and can be determined by various spectroscopic methods such as NMR and IR analysis.

[0094] 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. The number average molecular weight of component (A) is preferably 5,000 to 50,000. The weight average molecular weight and the number average molecular weight are obtained, for example, as polystyrene conversion values measured by gel permeation chromatography (GPC).

[0095] From the viewpoint of being easily processed by press curing when manufacturing laminates such as copper-clad laminates, the softening point of the component (A) of the present invention is preferably about 50°C to 250°C, more preferably about 80°C to 200°C. In addition, the softening point refers to the temperature at which the storage elastic modulus starts to decrease in the curve of the storage elastic modulus measured using a commercially available measuring instrument (product name "ARES-2KSTD-FCO-STD", manufactured by Rheometric Scientific Co., Ltd.) or the like.

[0096] The polyimide resin composition of the present invention contains two or more different organic solvents (B) (hereinafter referred to as component (B)).

[0097] The content of the component (B) in the polyimide resin composition of the present invention is not particularly limited, and is preferably 50 parts by mass to 1000 parts by mass (in terms of non-volatile components) relative to 100 parts by mass of the polyimide resin composition, and more preferably 100 parts by mass to 400 parts by mass (in terms of non-volatile components).

[0098] (B) component contains an ester (B1) (hereinafter referred to as component (B1)) and at least one organic solvent (B2) selected from the group consisting of ketones, ethers, aliphatic hydrocarbons, and alicyclic hydrocarbons (hereinafter referred to as component (B2)).

[0099] If the component (B1) is an ester, various known components can be used. Specifically, aliphatic esters, alicyclic esters, and aromatic esters can be mentioned. In addition, the aliphatic ester here means an ester without a cyclic structure, and also includes alkyl carbonates 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. If the component (B1) has the above boiling point, when the polyimide resin composition or the adhesive composition containing the composition is coated on the support film or copper foil, the component (B1) will not volatilize, so that the occurrence of coating unevenness or voids can be prevented. In addition, since the component (B1) becomes easily volatile when the coating layer of the above composition is dried, the component (B1) does not remain in the obtained cured product layer, and as a result, low dielectric characteristics are exhibited. In addition, the upper and lower limit values of the above boiling point can be 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, etc. In addition, for the same reason as above, the component (B1) is more preferably a boiling point of 70°C or higher and 140°C or lower. The above boiling point is an atmospheric pressure value, and the values described in the catalogs of chemical manufacturers and Chemical Book are adopted (the same applies hereinafter).

[0100] In the preferred component (B1), as aliphatic esters, for example, n-propyl formate (80 °C), isopropyl formate (68 °C), n-butyl formate (106 °C), isobutyl formate (98 °C), sec-butyl formate (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), isopropyl propionate (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), methyl ethyl carbonate (107 °C), diethyl carbonate (126 °C), etc. The temperature in parentheses indicates the boiling point of each compound under normal pressure (the same hereinafter).

[0101] In the preferred component (B1), as alicyclic esters, for example, methyl cyclopropylformate (119 °C), ethyl cyclopropylformate (131 °C), methyl cyclobutylformate (135 °C), etc.

[0102] These components (B1) can be used alone or in combination of two or more. Among them, from the viewpoint of good compatibility between component (A) and component (B1), aliphatic esters are preferred, and n-butyl acetate and diethyl carbonate are more preferred.

[0103] (B2) components can be various known components if they are ketones, ethers, aliphatic hydrocarbons, or alicyclic hydrocarbons. These (B2) components can be used alone or in combination of two or more. Among them, the (B2) component preferably has a boiling point of 60°C or higher and 150°C or lower. If the (B2) component has the above boiling point, when coating a polyimide resin composition or an adhesive composition containing the composition on a support film or a copper foil, the (B2) component will not volatilize, so that uneven coating or the generation of voids can be prevented. In addition, since the (B2) component becomes easy to volatilize when drying the coating layer of the above composition, no (B2) component remains in the obtained cured product layer, and as a result, low dielectric characteristics are exhibited. In addition, the upper limit and lower limit values of the above boiling point can be 145, 140, 135, 130, 125, 120, 115, 110, 105, 100, 95, 90, 85, 80, 75, 70, 65, etc. In addition, for the same reason as above, the (B2) component is more preferably a component having a boiling point of 70°C or higher and 140°C or lower.

[0104] Among the preferred (B2) components, as ketones, 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), etc. aliphatic ketones; methyl cyclopropanone (114°C), cyclobutanone (99°C), methyl cyclobutanone (138°C), cyclopentanone (131°C), etc. alicyclic ketones, etc. These can be used alone or in combination of two or more.

[0105] Among the preferred (B2) components, as ethers, for example, ethyl n-propyl ether (62°C), di-n-propyl ether (90°C), isopropyl n-propyl ether (83°C), diisopropyl ether (69°C), etc. 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), etc. aliphatic diethers; triethoxymethane (143°C), 1,1,1-trimethoxyethane (107°C), etc. aliphatic triethers; methoxycyclopentane (106°C), methoxycyclohexane (135°C), etc. alicyclic monoethers, etc. These can be used alone or in combination of two or more.

[0106] In the preferred component (B2), as aliphatic hydrocarbons, for example, n - alkanes such as n - hexane (69 °C), n - heptane (94 °C), n - octane (126 °C), etc.; mono - alkyl alkanes such as 2 - methylpentane (60 °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.; dialkyl alkanes such as 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), etc. These can be used alone or in combination of two or more.

[0107] In the preferred component (B2), as alicyclic hydrocarbons, for example, cycloalkanes such as cyclohexane (81 °C), cycloheptane (118 °C), etc.; mono - alkyl cycloalkanes such as ethylcyclobutane (70 °C), methylcyclopentane (72 °C), ethylcyclopentane (103 °C), n - propylcyclopentane (131 °C), isopropylcyclopentane (126 °C), isobutylcyclopentane (148 °C), methylcyclohexane (101 °C), ethylcyclohexane (132 °C), methylcycloheptane (145 °C), etc.; dialkyl cycloalkanes such as 1,1 - dimethylcyclohexane (118 °C), 1 - ethyl - 3 - methylcyclohexane (150 °C), etc. These can be used alone or in combination of two or more.

[0108] Among these component (B2), from the viewpoint of good compatibility between component (A) and component (B2), it is preferred to contain an ether and an alicyclic hydrocarbon.

[0109] As the content ratio of component (B1) and component (B2), in the production of component (A), from the viewpoint of being able to fully dissolve the generated polyamic acid and polyimide resin and remove the water generated as a by - product, in terms of mass ratio, it is preferred that (B1) / (B2)=10 / 90 - 90 / 10, more preferably 15 / 85 - 85 / 15, and further preferably 20 / 80 - 80 / 20.

[0110] [Adhesive composition]

[0111] The adhesive composition of the present invention comprises the polyimide resin composition of the present invention and a crosslinking agent.

[0112] The content of the polyimide resin composition in the adhesive composition of the present invention is not particularly limited. Taking the adhesive composition as 100% by mass, it is preferably about 10% to 99.5% by mass.

[0113] The content of the component (A) in the adhesive composition of the present invention is not particularly limited. Taking the non-volatile components of the adhesive composition as 100% by mass, it is preferably about 2% to 98% by mass.

[0114] As long as it is a substance that functions as a crosslinking agent for polyimide, various known crosslinking agents can be used without particular limitation. The crosslinking agent can be used alone or in combination of two or more. The crosslinking agent is preferably at least one selected from the group consisting of epoxides, benzoxazines, bismaleimides, and cyanates.

[0115] Examples of epoxides include phenol novolac type epoxides, cresol novolac type epoxides, bisphenol A type epoxides, bisphenol F type epoxides, bisphenol S type epoxides, hydrogenated bisphenol A type epoxides, hydrogenated bisphenol F type epoxides, stilbene type epoxides, epoxides containing a triazine skeleton, epoxides containing a fluorene skeleton, linear aliphatic epoxides, alicyclic epoxides, glycidylamine type epoxides, triphenol methane type epoxides, alkyl-modified triphenol methane type epoxides, biphenyl type epoxides, epoxides containing a dicyclopentadiene skeleton, epoxides containing a naphthalene skeleton, arylalkylene type epoxides, tetraglycidylbenzene dimethyldiamine, dimer acid-modified epoxides as dimmer acid-modified products of the above epoxides, dimer acid diglycidyl esters, etc. In addition, as commercially available products of epoxides, there are "jER828", "jER834", "jER807", "jER604", "jER630" manufactured by Mitsubishi Chemical Corporation; "ST-3000" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "Celloxide 2021P" manufactured by Daicel Corporation; "YD-172-X75" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "TETRAD-X" manufactured by Mitsubishi Gas Chemical Company, Inc., etc. Among these epoxides, from the viewpoint of the balance between soldering heat resistance and low dielectric characteristics, at least one selected from the group consisting of bisphenol A type epoxides, bisphenol F type epoxides, hydrogenated bisphenol A type epoxides, and alicyclic epoxides is preferred.

[0116] Specifically, the tetraglycidyl diamine of the general formula (3) has good compatibility with the above polyimide. In addition, when this substance is used, it becomes easy to increase the low-loss elastic modulus of the adhesive layer (increase the loss elastic modulus), and its soldering heat resistance and low dielectric properties also become good.

[0117] [Chemical Formula 3]

[0118]

[0119] (In the formula, Z represents a phenylene group or a cyclohexylene group.)

[0120] When an epoxy is used as the crosslinking agent, various known curing agents for epoxy and active ester-based curing agents can be used in combination. These curing agents can be used alone or in combination of two or more.

[0121] Examples of the curing agent for epoxy include:

[0122] Acid anhydride-based curing agents such as succinic anhydride, phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic dianhydride, hexahydrophthalic anhydride, 3-methyl-hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride, or a mixture of 4-methyl-hexahydrophthalic anhydride and hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl-tetrahydrophthalic anhydride, nadic anhydride, methyl nadic anhydride, norbornane-2,3-dicarboxylic anhydride, methyl norbornane-2,3-dicarboxylic anhydride, methylcyclohexene dicarboxylic anhydride, 3-dodecenyl succinic anhydride, octenyl succinic anhydride;

[0123] Amine-based curing agents such as dicyandiamide (DICY), aromatic diamines (trade names “Lonzacure M-DEA”, “Lonzacure M-DETDA”, etc.; all manufactured by Lonza Japan Co., Ltd.), aliphatic amines;

[0124] Phenol novolac resins, cresol novolac resins, bisphenol A type novolac resins, triazine-modified phenol novolac resins, phenol hydroxyl group-containing phosphazenes (trade names “SPH-100”, etc. manufactured by Otsuka Chemical Co., Ltd.) and other phenol-based curing agents;

[0125] Rosin-based curing agents such as maleic acid-modified rosin and its hydrides;

[0126] Cyclic phosphazene compounds and the like.

[0127] Examples of the active ester-based curing agent include substances containing a dicyclopentadienyl diphenol structure, substances containing a naphthalene structure, acetylated products of phenol novolac, benzoylated products of phenol novolac, etc. described in JP-A-2019-183071.

[0128] Examples of commercially available active ester-based curing agents include:

[0129] Examples of substances containing a dicyclopentadienyl diphenol structure are "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);

[0130] Examples of substances containing a naphthalene structure are "EXB9416-70BK" (manufactured by DIC Corporation);

[0131] Examples of acetylated novolak phenol resins are "DC808" (manufactured by Mitsubishi Chemical Corporation);

[0132] Examples of benzoylated novolak phenol resins are "YLH1026", "YLH1030", "YLH1048" (manufactured by Mitsubishi Chemical Corporation), etc.

[0133] Active ester-based curing agents may also be substances manufactured by various known methods. Examples thereof include substances obtained by reacting a polyfunctional phenol compound with an aromatic carboxylic acid as described in Japanese Patent No. 5152445.

[0134] Among the above curing agents, active ester-based curing agents and phenolic curing agents are preferred, and active ester-based curing agents are particularly preferred. The amount of the curing agent used is not particularly limited. Based on 100% by mass of the non-volatile components of the above adhesive composition, it is preferably about 0.1% to 40% by mass, and more preferably about 1% to 10% by mass.

[0135] In addition, when using an epoxide and an epoxide curing agent in combination as crosslinking agents, a reaction catalyst can be further used in combination. The reaction catalyst can be used alone or two or more thereof can be used in combination. Examples of the reaction catalyst include tertiary amines such as 1,8-diazabicyclo[5.4.0]undec-7-ene, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-heptadecylimidazole; organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, and phenylphosphine; and tetraphenylphosphonium·tetraphenylborate, 2-ethyl-4-methylimidazole·tetraphenylborate, N-methylmorpholine·tetraphenylborate, and other tetraphenylborate salts. In addition, the amount of use of the reaction catalyst is not particularly limited. Taking the non-volatile components of the above adhesive composition as 100% by mass, it is preferably about 0.01% to 5% by mass.

[0136] Examples of benzoxazine include 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), etc. In addition, a phenyl group, a methyl group, a cyclohexyl group, etc. can be bonded to the nitrogen of the oxazine ring. In addition, as commercially available products of benzoxazine, there are "Benzoxazine F-a type", "Benzoxazine P-d type" manufactured by Shikoku Kasei Kogyo Co., Ltd.; "RLV-100" manufactured by Air Water Co., Ltd., etc.

[0137] Examples of bismaleimide include 4,4'-diphenylmethane bismaleimide, m-phenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenyl sulfone bismaleimide, etc. In addition, as commercially available products of bismaleimide, there are "BAF-BMI" manufactured by JFE Chemical Co., Ltd., "BMI-1000H" manufactured by Yamato Kasei Kogyo Co., Ltd., etc.

[0138] Examples of the cyanate ester include 2-allylphenol cyanate ester, 4-methoxyphenol cyanate ester, 2,2-bis(4-isocyanatophenyl)-1,1,1,3,3,3-hexafluoropropane (2,2-bis(4-isocyanatophenyl)-1,1,1,3,3,3-hexafluoropropane), bisphenol A cyanate ester, diallylbisphenol 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'-bisphenol cyanate ester, 2,2-bis(4-cyanatophenyl)propane, and the like. In addition, as commercially available products of the cyanate ester, "PRIMASET BTP-6020S" manufactured by Lonza Japan Co., Ltd. and the like are cited.

[0139] The content of the crosslinking agent in the adhesive composition of the present invention is not particularly limited. With respect to 100 parts by mass (in terms of non-volatile components) of the component (A) of the present invention in the above adhesive composition, the content of the crosslinking agent is preferably about 1 part by mass to 900 parts by mass.

[0140] Regarding the non-volatile components of the adhesive composition as 100% by mass, the content of the crosslinking agent in the adhesive composition of the present invention is preferably about 1% by mass to 80% by mass.

[0141] The adhesive composition of the present invention may contain a flame retardant. The flame retardant can be used alone or in combination of two or more. Examples of the flame retardant include phosphorus-based flame retardants, inorganic fillers, and the like.

[0142] Examples of the phosphorus-based flame retardants include polyphosphoric acid, phosphate esters, phosphorus nitride derivatives without phenolic hydroxyl groups, and the like. Among these phosphorus nitride derivatives, cyclic phosphorus nitride derivatives are preferred from the viewpoints of flame retardancy, heat resistance, bleed-out resistance, and the like. As commercially available products of the cyclic phosphorus nitride derivatives, "SPB-100" manufactured by Otsuka Chemical Co., Ltd., "Rabitol FP-300B" manufactured by Fushimi Pharmaceutical Co., Ltd., and the like are cited.

[0143] Examples of the inorganic fillers include silica fillers, phosphorus fillers, fluorine fillers, inorganic ion exchange body fillers, and the like. In addition, as the silica filler, a silica filler whose surface is modified with a treating agent such as a silane coupling agent can also be used. In addition, as commercially available products of the inorganic fillers, "FB-3SDC", "SFP-20M" manufactured by Denka Co., Ltd., "SC-2500-SPJ", "SC-2500-SXJ", "SC-2500-SVJ" manufactured by Admatechs Co., Ltd., "Exolit OP935" manufactured by Clariant Chemicals Co., Ltd., "KTL-500F" manufactured by Kitamura Co., Ltd., "IXE" manufactured by Toagosei Co., Ltd., and the like are cited.

[0144] The content of the flame retardant in the adhesive composition of the present invention is not particularly limited. With respect to 100 parts by mass (in terms of non-volatile components) of the component (A) of the present invention in the above adhesive composition, the content of the flame retardant is preferably 1 part by mass to 150 parts by mass.

[0145] The adhesive composition of the present invention may also contain a reactive alkoxysilyl compound represented by the general formula W-Si(R 1 ) a (OR 2 ) 3-a (wherein W represents a group containing a functional group reactive 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). By the reactive alkoxysilyl compound, the low dielectric constant characteristics of the adhesive layer formed from the adhesive composition of the present invention can be maintained while adjusting its melt viscosity. As a result, the interfacial adhesion force (so-called anchor effect) between the adhesive layer and the support can be improved, and at the same time, the exudation of the cured layer from the end of the support can be suppressed.

[0146] Examples of the reactive functional group contained in W in the above general formula include an amino group, an epoxy group, and a thiol group.

[0147] When W is a group containing an amino group, examples include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3-ureidopropyltrialkoxysilane. When W is a group containing an epoxy group, for example, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane. When W is a group containing a thiol group, for example, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropylmethyldiethoxysilane. Among these groups, since the reactivity and flow control effect are good, it is preferred that W is a group containing an amino group.

[0148] The content of the reactive alkoxysilyl compound in the adhesive composition of the present invention is not particularly limited. With respect to 100 parts by mass (in terms of non-volatile components) of the component (A) of the present invention in the above adhesive composition, the content of the reactive alkoxysilyl compound is preferably 0.01 part by mass to 5 parts by mass.

[0149] The adhesive composition of the present invention may contain, as an additive, a substance selected from any one of a polyimide resin composition, a crosslinking agent, a flame retardant, a reactive alkoxysilyl compound, and the above-mentioned organic solvent, which does not belong to the present invention.

[0150] Examples of the additive include a catalyst for ring-opening esterification reaction, a dehydrating agent, a plasticizer, a weathering agent, an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, a brightening agent, a colorant, a conductive agent, a release agent, a surface treatment agent, a viscosity modifier, a silica filler, and a fluorine filler.

[0151] The content of the above-mentioned additive is not particularly limited, and examples include 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., based on 100 parts by mass of the non-volatile components of the adhesive composition.

[0152] The content of the above-mentioned additive is not particularly limited, and examples include 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., based on 100 parts by mass (in terms of non-volatile components) of the component (A) of the present invention.

[0153] The adhesive composition of the present invention can be obtained by dissolving the above-mentioned crosslinking agent and, if necessary, the above-mentioned flame retardant, reactive alkoxysilyl compound, and additive in the polyimide resin composition of the present invention. Additionally, in the preparation of the above-mentioned adhesive composition, the above-mentioned component (B) can be further incorporated.

[0154] [Film-like Adhesive Material]

[0155] The film-like adhesive material of the present invention comprises a cured product of the adhesive composition of the present invention. Examples of the manufacturing method of the film-like adhesive material include a method comprising the following steps: a step of coating the above-mentioned adhesive composition on a suitable support, a step of curing it by heating to volatilize the organic solvent, a step of peeling off the support, etc. In addition, the thickness of the adhesive material is not particularly limited, and is preferably about 3 μm to 40 μm. Examples of the support include release paper, release film, and the support film described later. In addition, when manufacturing the above-mentioned film-like adhesive material, various known adhesive compositions other than the above-mentioned adhesive composition can be used in combination with the above-mentioned adhesive composition.

[0156] [Adhesive Sheet]

[0157] The adhesive sheet of the present invention has the film-like adhesive material of the present invention on at least one surface of a support film.

[0158] The above-mentioned adhesive sheet can be obtained, for example, by coating the adhesive composition of the present invention on a support film and curing it by heating, or by laminating the film-like adhesive material of the present invention on a support film.

[0159] Examples of the above-mentioned support films include polyimide; polyester; polyimide-silica mixture (hybrid); polyethylene; polypropylene; polyethylene terephthalate; polyethylene naphthalate; polymethyl methacrylate resin; polystyrene resin; polycarbonate resin; acrylonitrile-butadiene-styrene resin; aromatic polyester resins (so-called liquid crystal polymers; manufactured by Kuraray Co., Ltd., "Vectra", etc.) obtained from ethylene glycol terephthalate, phenol, phthalic acid, hydroxy naphthoic acid, etc. and p-hydroxybenzoic acid; cycloolefin polymers; fluorine-based resins (polytetrafluoroethylene (PTFE), perfluoroalkoxy alkane (PFA), polyvinylidene fluoride (PVDF), etc.). The polyimide includes the above-mentioned polyimide film of the present invention.

[0160] When the adhesive composition of the present invention is coated on the above-mentioned support film, the coating method is not particularly limited, and examples include coating with a comma coater, die coater, knife coater, lip coater, etc. The thickness of the coating layer is also not particularly limited, and the thickness after drying is preferably about 1 μm to 100 μm, more preferably about 3 μm to 50 μm. In addition, the adhesive layer of the adhesive sheet can also be protected with various protective films.

[0161] [Resin-coated copper foil]

[0162] The resin-coated copper foil of the present invention includes the film-like adhesive material of the present invention and copper foil. Specifically, the resin-coated copper foil can be obtained by coating the adhesive composition of the present invention on the copper foil and heating and curing it, or can be obtained by laminating the film-like adhesive material of the present invention on the copper foil. Examples of the copper foil include rolled copper foil and electrolytic copper foil, and copper foils subjected to various surface treatments (roughening, rust prevention, etc.) can also be used. Examples of the rust prevention treatment include plating treatment using a plating solution containing Ni, Zn, Sn, etc., and so-called mirror finishing treatment such as chromate treatment.

[0163] The thickness of the copper foil is not particularly limited, and is preferably about 1 μm to 100 μm, more preferably about 2 μm to 38 μm. In addition, as the coating method, the above-mentioned methods are exemplified.

[0164] In addition, the adhesive layer or the film-like adhesive material of the resin-coated copper foil may be uncured, or may be partially cured or completely cured under heating. The partially cured adhesive layer or film-like adhesive material is in a state called the so-called B stage (B stage). In addition, the thickness of the adhesive layer or the film-like adhesive material is not particularly limited, and is preferably about 0.5 μm to 30 μm. In addition, a resin can be further laminated on the copper foil of the resin-coated copper foil to produce a double-sided resin-coated copper foil.

[0165] [Copper-clad laminate]

[0166] The copper-clad laminate of the present invention comprises the resin-coated copper foil of the present invention and a copper foil or an insulating sheet. The copper-clad laminate is also known as CCL (Copper Clad Laminate). Specifically, the copper-clad laminate is obtained by press-bonding the above resin-coated copper foil onto at least one or both sides of various known copper foils or insulating sheets under heating. In the case of bonding to one side, a material different from the above resin-coated copper foil may also be press-bonded to the other side. In addition, the number of resin-coated copper foils, copper foils, and insulating sheets in the copper-clad laminate is not particularly limited.

[0167] In one embodiment, the insulating sheet is preferably a prepreg or the above support film. A prepreg is a sheet material (JIS C 5603) obtained by impregnating a reinforcing material such as glass cloth with a resin and curing it to the B stage. The resin used is an insulating resin such as the component (A) of the present invention, phenolic resin, epoxy resin, polyester resin, liquid crystal polymer, aromatic polyamide resin, etc. The thickness of the insulating sheet is not particularly limited, and is preferably about 20 μm to 500 μm. The heating and press-bonding conditions are not particularly limited, and are preferably about 150°C to 280°C (more preferably about 170°C to 240°C); preferably about 0.5 MPa to 20 MPa (more preferably about 1 MPa to 8 MPa).

[0168] [Printed Wiring Board]

[0169] 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. As a layout method for forming a circuit pattern on the copper foil surface of the copper-clad laminate, subtractive method and semi-additive method are cited. As the semi-additive method, the following method is cited: After laying out with a resist film on the copper foil surface of the copper-clad laminate, electrolytic copper plating is performed, the resist is removed, and etching is performed with an alkaline solution. In addition, the thickness of the circuit pattern layer in the printed wiring board is not particularly limited. In addition, the printed wiring board may be used as a core substrate, and the same printed wiring board, other known printed wiring boards, or printed circuit boards may be laminated on the core substrate to obtain a multilayer substrate. When laminating, the above adhesive composition and other known adhesive compositions other than the above adhesive composition may be used in combination. In addition, the number of laminations in the multilayer substrate is not particularly limited. In addition, via holes may be inserted and provided at each lamination, and internal plating treatment may be performed. The line width / spacing ratio (line / space ratio) of the above circuit pattern is not particularly limited, and is preferably about 1 μm / 1 μm to 100 μm / 100 μm. In addition, the height of the above circuit pattern is not particularly limited, and is preferably about 1 μm to 50 μm.

[0170] [Polyimide Film]

[0171] The polyimide film of the present invention is a cured product of the polyimide resin composition of the present invention.

[0172] As a method for producing the polyimide film of the present invention, after coating the above polyimide resin composition on the above support, it is cured by heating, and after forming a polyimide resin layer, the support is peeled off from the polyimide resin layer, etc.

[0173] As a method for coating the polyimide resin composition on the support, it is not particularly limited, and the above coating method is cited. In addition, the heat treatment conditions are not particularly limited, and for example, a method of heating at a temperature of about 100°C to 180°C for about 0.5 hour to 3 hours is cited.

[0174] The thickness of the polyimide resin layer after heat treatment is not particularly limited, and the thickness after drying is preferably about 1 μm to 50 μm.

[0175] As long as the effects of the present invention are not impaired, the polyimide resin composition for the polyimide film of the present invention may contain various additives. Examples of such additives include dehydrating agents, plasticizers, weather resistance agents, antioxidants, heat stabilizers, lubricants, antistatic agents, brightening agents, colorants, conductive agents, mold release agents, surface treatment agents, viscosity regulators, inorganic fillers, inorganic pigments, organic pigments, etc.

[0176] As inorganic fillers, for example, silica fillers, phosphorus-based fillers, fluorine-based fillers, inorganic ion exchange body fillers, etc. are cited. In addition, as the silica filler, a silica filler whose surface is modified with a treating agent such as a silane coupling agent can also be used. In addition, as commercially available products of inorganic fillers, “FB-3SDC” and “SFP-20M” manufactured by Denka Co., Ltd., “SC-2500-SPJ”, “SC-2500-SXJ”, “SC-2500-SVJ” manufactured by Admatechs Co., Ltd., “Exolit OP935” manufactured by Clariant Chemicals Co., Ltd., “KTL-500F” manufactured by Kitamura Co., Ltd., “IXE” manufactured by Toagosei Co., Ltd., etc. are cited.

[0177] As inorganic pigments, cadmium red, cadmium lemon yellow, cadmium yellow orange, titanium dioxide, carbon black, black iron oxide, black complex inorganic pigments, etc. are cited.

[0178] As organic pigments, aniline black, perylene black, anthraquinone black, benzidine-based yellow pigments, phthalocyanine blue, phthalocyanine green, etc. are cited.

[0179] The content of the additive in the polyimide resin composition of the present invention is not particularly limited, and is preferably 1 part by mass to 150 parts by mass relative to 100 parts by mass (in terms of non-volatile components) of the component (A).

[0180] Examples

[0181] Hereinafter, examples will be given to specifically illustrate the present invention, but the present invention is not particularly limited to these examples. In addition, unless otherwise specified, "%" is based on mass.

[0182] Example 1

[0183] In a reaction vessel equipped with a stirrer, a water separator, a thermometer, and a nitrogen inlet tube, 200.0 g of 4,4'-[propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic anhydride (trade name "BisDA-1000", manufactured by SABIC Innovative Plastics Japan Co., Ltd.; hereinafter simply referred to as BisDA), 619.0 g of diethyl carbonate, 132.6 g of 1,2-dimethoxyethane, and 132.6 g of methylcyclohexane were added and heated to 75°C. Then, 197.8 g of a dimer diamine (trade name "PRIAMINE 1075", manufactured by Clariant Japan K.K.; hereinafter referred to as PRIAMINE1075) was slowly added, and after heating to 115°C, an imidization reaction was carried out for 10 hours to obtain a solution of polyimide (non-volatile content 30%). The obtained solution was used as a polyimide resin composition (the same applies hereinafter).

[0184] Examples 2 to 18, Comparative Example 1

[0185] The composition and usage amount were changed to those shown in Table 1, and the same method as in Example 1 was used to obtain polyimide resins with a non-volatile content of 30% respectively.

[0186] Comparative Example 2, Comparative Example 3

[0187] The type of solvent was changed to the solvent shown in Table 1, and the same method as in Example 1 was used, but the resulting polyamic acid was insoluble and no polyimide was obtained.

[0188] <Production of Evaluation Samples>

[0189] The polyimide resin compositions of Examples 1 to 18 and Comparative Example 1 were coated on release paper (manufactured by Sun-A Kaken Co., Ltd.), dried at 150°C for 5 minutes and then further dried at 170°C for 30 minutes, and then the release paper was peeled off to obtain a polyimide film with a thickness of 25 μm. This film was laminated in two layers and melted by hot pressing at 120°C to produce evaluation samples.

[0190] <Measurement of Relative Dielectric Constant and Dielectric Loss Tangent>

[0191] The resonance frequency of a single resonator without inserting any substance and the Q value of its peak were measured using a network analyzer ("P5003A" manufactured by Keysight Technologies) and a split post dielectric resonator (manufactured by QWED) with a measurement frequency of 10.124 GHz.

[0192] Next, after cutting the above evaluation sample into test pieces of 4 cm × 5 cm, multiple test pieces were overlapped so that the total thickness was 100 μm or more and inserted into the resonator, and then the resonance frequency and Q value when the test pieces were inserted were measured.

[0193] The relative dielectric constant (Dk) was calculated from the difference in resonance frequency between the single resonator and when the test pieces were inserted, and the dielectric loss tangent (Df) was calculated from the difference in Q value and the difference in resonance frequency between the single resonator and when the test pieces were inserted. The results are shown in Table 1.

[0194]

[0195] The abbreviations in Table 1 are as follows.

[0196] <Aromatic tetracarboxylic dianhydride>

[0197] (a1) component

[0198] · BisDA: 4,4'-[Propane-2,2-diylbis(1,4-phenyleneoxy)]diphthalic anhydride, trade name: "BisDA-1000", manufactured by SABIC Innovative Plastics Japan Co., Ltd.

[0199] · 6FDA: 2,2-Bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, manufactured by Daikin Industries, Ltd.

[0200] <Diamine>

[0201] (a2) component

[0202] · DDA: Dimer diamine, trade name: "PRIAMINE 1075", manufactured by Croda Japan Co., Ltd.

[0203] · ODA: 4,4'-Diaminodiphenyl ether, manufactured by Wakayama Seika Kogyo Co., Ltd.

[0204] <Organic solvent>

[0205] (B1) component

[0206] · DEC: Diethyl carbonate (boiling point: 126°C)

[0207] · AcOBu: n-Butyl acetate (boiling point: 126°C)

[0208] (Component (B2))

[0209] · DMG: 1,2 - Dimethoxyethane (boiling point: 82 °C)

[0210] · MEK: Methyl ethyl ketone (boiling point: 80 °C)

[0211] · MIBK: Methyl isobutyl ketone (boiling point: 116 °C)

[0212] · MCH: Methylcyclohexane (boiling point: 101 °C)

[0213] · OCT: n - Octane (boiling point: 126 °C)

[0214] · C - 800: 2 - Methylheptane (boiling point: 116 °C, trade name: "KYOWASOL C - 800", manufactured by KH Neochem Co., Ltd.)

[0215] (Other solvents)

[0216] · DMAc: N,N - Dimethylacetamide (boiling point: 165 °C)

[0217] (Production of adhesive composition)

[0218] Evaluation Example 1

[0219] 100.0 g of the polyimide resin composition of Example 1 (non - volatile content: 30.0 g), 0.78 g of a polyfunctional epoxy resin as a cross - linker (trade name: "TETRAD - X", manufactured by Mitsubishi Gas Chemical Co., Ltd.) (non - volatile content: 0.78 g), 2.67 g of an active ester resin as a curing agent (trade name: "EPICLON HPC - 8000 - 65T", manufactured by DIC Corporation) (non - volatile content: 1.75 g), 0.008 g of an imidazole - type epoxy resin (trade name: "CUREZOL 2E4MZ - A", manufactured by Shikoku Kasei Kogyo Co., Ltd.) (non - volatile content: 0.008 g), 32.5 g of silica as an inorganic filler (trade name: "SC - 2500 - SPJ", manufactured by Admatechs Co., Ltd.) (non - volatile content: 32.5 g), and 62.1 g of cyclopentanone as an organic solvent were mixed and thoroughly stirred to obtain an adhesive composition with a non - volatile content of 33%.

[0220] Evaluation Examples 2 to 4, Comparative Evaluation Example 1

[0221] Using the polyimide resin compositions shown in Table 2 respectively, the same method as in Evaluation Example 1 was carried out to obtain adhesive compositions with a non - volatile content of 33% respectively.

[0222] (Production of adhesive sheet)

[0223] The obtained adhesive composition was coated on a release paper (manufactured by Sun-A Chemical Research Co., Ltd.) using a gap coater, and after drying to a thickness of 25 μm, it was dried at 150 °C for 5 minutes to obtain an adhesive sheet (release paper / adhesive layer).

[0224] <Measurement of relative permittivity and dielectric loss tangent>

[0225] The release paper was peeled off from the above-mentioned adhesive sheet (release paper / adhesive layer), and the adhesive layer was placed on a pressing support. Then, it was cured by heating and pressing at 5 MPa and 180 °C for 90 minutes through the same pressing support on the adhesive layer side to produce a thermally cured adhesive sheet (support / adhesive layer / support). The pressing support was removed from this adhesive sheet, and for the adhesive layer, the relative permittivity (Dk) and dielectric loss tangent (Df) were calculated by the same method as in the above paragraph. The results are shown in Table 2.

[0226] <Manufacture of copper-clad laminate>

[0227] The release paper was peeled off from the above-mentioned adhesive sheet (release paper / adhesive layer), and it was overlapped on the mirror side of a commercially available electrolytic copper foil (product name "F2-WS", manufactured by Furukawa Electric Co., Ltd.) (film thickness 18 μm), and the other side was overlapped on a commercially available polyimide film (product name "Kapton 100EN", manufactured by Toray DuPont Co., Ltd.; film thickness 25 μm; coefficient of thermal expansion: 15 ppm / °C) to produce a laminate of polyimide film - adhesive layer - electrolytic copper foil. Then, it was placed on a pressing support and cured by heating and pressing at 5 MPa and a temperature of 180 °C for 90 minutes through the support made of the same material from above to produce a copper-clad laminate.

[0228] <Adhesion test>

[0229] For the above-mentioned copper-clad laminate, the peel strength (N / mm) was measured according to JIS C 6481 (Test methods for copper-clad laminates for flexible printed wiring boards). The results are shown in Table 2.

[0230] <Soldering heat resistance test>

[0231] After the above-mentioned copper-clad laminate was placed in a constant temperature chamber at 23 °C and 50% humidity for 24 hours, with the copper foil side facing down, it was floated in a solder bath at 288 °C to confirm the presence or absence of foaming, and the evaluation was carried out according to the following criteria. The results are shown in Table 2.

[0232] (Evaluation criteria)

[0233] ○: The appearance has not changed

[0234] ×: Foaming, swelling

[0235] [Table 2]

[0236]

Claims

1. A polyimide resin composition, the polyimide resin composition comprising a polyimide (A) and two or more different organic solvents (B). The polyimide (A) is a reaction product of a monomer group comprising an aromatic tetracarboxylic dianhydride (a1) and a diamine (a2) containing a dimer diamine. Component (B) does not contain an organic solvent containing a nitrogen atom and an aromatic hydrocarbon. Component (B) comprises 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. The boiling point of component (B1) is 60°C or higher and 150°C or lower, and the boiling point of component (B2) is 60°C or higher and 150°C or lower. Component (B1) is at least one selected from the group consisting of diethyl carbonate and n-butyl acetate. Component (B2) is at least one selected from the group consisting of 1,2-dimethoxyethane, methyl ethyl ketone, methyl isobutyl ketone, methylcyclohexane, n-octane, and 2-methylheptane.

2. The polyimide resin composition according to claim 1, wherein, Component (a2) further comprises an alicyclic diamine and / or an aromatic diamine.

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

4. An adhesive composition, the adhesive composition comprising the polyimide resin composition according to any one of claims 1 to 3 and a crosslinking agent.

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