JP5139986B2 - POLYIMIDE RESIN COMPOSITION, PROCESS FOR PRODUCING THE SAME, AND METAL LAMINATE - Google Patents

Description

  The present invention relates to a polyimide resin composition, a method for producing the same, and a metal laminate having a resin layer made of the resin composition.

  Polyimide is used in aircraft structural materials and cable coating materials because of its excellent heat resistance, chemical resistance, mechanical strength, electrical properties, etc. In addition, it is represented by flexible printed circuit boards and semiconductor packages. It is also widely applied as a heat-resistant adhesive used in the electronic field.

Moreover, an electrical circuit may be produced from the metal laminated body which uses a polyimide-type adhesive as a resin layer. In some cases, a chip or an electronic component is mounted on the polyimide metal laminate using solder, or a chip or electronic component called a repair is removed. In recent years, from the viewpoint of environmental conservation, lead-free solder has been used for mounting chips and electronic components, and therefore, more excellent “solder heat resistance” is required.
Further, in applications called rigid flex and flexible multilayer substrates, it has been pointed out that reliability is insufficient at solder heat resistance temperatures that have been conventionally required, and higher heat resistance is desired.

  When a metal laminate having a polyimide adhesive as a resin layer is used as a chip-on-film (hereinafter sometimes abbreviated as “COF”), the bonding between the chip and the metal wiring is performed by an inner lead bonder or a flip chip. Using a bonder, Au—Au bonding or Au—Sn bonding is performed. Since Au—Au bonding or Au—Sn bonding requires a high temperature condition of 300 ° C. or higher, a substrate excellent in soldering heat resistance is desired even when used for COF.

  Furthermore, recent polyimide-based heat-resistant adhesives are required to have low-temperature adhesiveness in addition to heat-resistant characteristics from the viewpoint of processing characteristics. However, adhesion with a conventional resin composition containing a specific polyamic acid may require an adhesion temperature of 300 ° C. or higher, and many are still insufficient from the viewpoint of low-temperature adhesion.

  Thus, polyimide adhesives are required to have both improved heat resistance and improved low-temperature adhesion. As a polyimide heat-resistant adhesive having sufficient adhesive strength and heat resistance, a resin composition composed of a specific polyamic acid and bismaleimide has been developed (see, for example, Patent Documents 1 to 4).

  On the other hand, when an electric circuit is produced from a metal laminate having a polyimide adhesive as a resin layer, through-hole formation (via processing) may be performed by laser processing. In the formation of through-holes, generally, a treatment (also referred to as “desmear treatment”) for removing a resin layer (also referred to as “smear”) that could not be removed by laser processing with an alkaline solution is performed. From the viewpoint of productivity, it is preferable that smear be removed quickly (desmear speed is high), that is, a polyimide adhesive having high solubility in an alkaline solution is desired. However, polyimide adhesives with improved low temperature adhesion tend to have a low desmear rate.

Moreover, a resin composition composed of a bismaleimide compound and a polyamic acid has been reported as a polyimide heat-resistant adhesive having sufficient low-temperature adhesiveness (see Patent Document 5). However, when a resin composition containing bismaleimide is used for the resin layer of the metal laminate, a volatile substance (bismaleimide) is generated depending on the production conditions, which may cause production problems. In addition, when applying or laminating a resin composition, volatile substances may affect production facilities.
JP-A-1-289862 JP-A-6-145638 Japanese Patent Laid-Open No. 6-192939 JP-A-2-274762 Japanese Patent Laid-Open No. 2004-209962

The object of the present invention is to increase the desmear property (increase the desmear speed) while maintaining the low-temperature adhesiveness of the polyimide resin composition (that thermocompression bonding is possible under relatively low temperature conditions). . Another object of the present invention is to provide a polyimide resin composition excellent in processability by suppressing the generation of volatile substances during processing while maintaining low temperature adhesion.
Furthermore, the metal laminated body preferably applied as a flexible printed circuit board etc. is provided using the resin composition of this invention.

1st of this invention is related with the polyimide-type resin composition shown below.
[1] A repeating unit represented by the following general formula (1-1), a polyimide resin containing a repeating unit represented by the general formula (1-2), and an imide oligomer represented by the following general formula (2) Containing a polyimide resin composition.

[In the formula (1-1) and (1-2), _{A 1} and _{A 2} are each the following formula (a1) or (a2), or different and are identical to each other, _{B 1} and B ₂ is the following formula (b1) or (b2), which may be the same or different from each other]

[In the formula (2), A ₃ is any one of the following formulas (c1) to (c4), B ₃ is any one of the following formulas (d1) to (d4), and Z is a formula (E1) or (e2), and l is an integer of 1 to 5]

[In formulas (c1) to (c4), X _{7 to 12} are a direct _bond , —O—, —S—, —CO—, —COO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ). _{2 -, - SO 2 -,} - is selected from the group consisting of NHCO-, may be the same or different from each other]

[In formulas (d1) to (d4), _{Y7 to 12} are a direct _bond , —O—, —S—, —CO—, —COO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ). _{2 -, - SO 2 -,} - is selected from the group consisting of NHCO-, may be the same or different from each other]

[In Formula (e1) or (e2), R _1-4 are selected from the group consisting of a hydrogen atom, a halogen atom, and an alkyl group having 1 to 3 carbon atoms, and may be the same or different from each other. , R ₅ is —O—, —S—, —CH ₂ —, —C (CH ₃ ) ₂ —, —CO—, or —COO—.

[2] In [1], any one of A ₁ in the general formula (1-1) and A ₂ in the general formula (1-2) is (a1) and the other is (a2). The polyimide resin composition described. [3] The polyimide resin composition according to [1] or [2], wherein l in the general formula (2) is 1. [4] In any one of [1] to [3], containing 5 parts by weight or more and 100 parts by weight or less of the imide oligomer represented by the general formula (2) with respect to 100 parts by weight of the polyimide resin. Polyimide resin composition. [5] The polyimide resin composition according to claim 1, wherein the glass transition temperature is in the range of 100 ° C to 300 ° C. [6] In the general formula (2), A ₃ is the following formula (c5) or (c6), and B ₃ is selected from the group consisting of the following formulas (d1) and (d5) to (d10) The polyimide resin composition according to any one of [1] to [5], wherein Z is (e3) or (e4), and l is an integer of 1 to 5.

[R ₃ and R ₄ are defined in the same manner as in the formula (e2)]

[7] Polyamic acid containing a repeating unit represented by the following general formula (3-1) and a repeating unit represented by the following general formula (3-2), an imide oligomer represented by the general formula (2) , As well as optionally a solvent.

[In the formula (3-1) and (3-2), _{A 1} and _{A 2} are each the formula (a1) or (a2), or different and are identical to each other, _{B 1} and B ₂ is the formula (b1) or (b2), respectively, which may be the same or different from each other]

[In the formula (2), _{A 3} is any of the formulas (c1) ~ (c4), B 3 is any of the formulas (d1) ~ (d4), Z is the formula (E1) or (e2), and l is an integer of 1 to 5]

[8] A method for producing a cured polyimide resin, comprising a step of heating the mixture according to [7] to cause an imidization reaction.

In addition, this invention relates to the member shown below. [9] A film containing a cured product of the polyimide resin composition according to any one of [1] to [6]. [10] A metal laminate comprising a metal layer and a resin layer, wherein at least one of the resin layers is a metal laminate comprising a cured product of the polyimide resin composition according to any one of [1] to [6]. body. [11] having a polyimide film, a polyimide layer formed on one or both sides of the polyimide film, a metal layer laminated on one or both of the polyimide layers,
The metal laminated body whose polyimide layer which contact | connects the said metal layer is a resin layer which consists of a hardened | cured material of the polyimide resin composition in any one of [1]-[6]. [12] An adhesive sheet having a resin film and a resin layer made of a cured product of the polyimide resin composition according to any one of [1] to [6], which is laminated on one side or both sides of the resin film.

  The polyimide resin composition of the present invention is excellent in low-temperature adhesiveness, has high desmearing properties (high desmearing speed), and suppresses generation of volatile substances during processing.

In addition, the polyimide resin composition of the present invention can be used to produce a metal laminate by bonding a metal layer and a resin layer, but it is not necessary to use a high processing temperature in the bonding, so the metal layer and the polyimide interface Voids hardly remain. Therefore, a metal laminate having high adhesive strength between the metal layer and the resin layer can be obtained. The obtained metal laminate can be suitably used as a flexible printed circuit board or the like.
The resulting metal laminate and the adhesive sheet that is the precursor of the metal laminate (sheet without the metal layer) are excellent in soldering heat resistance. Swelling is unlikely to occur in the repair process.

1. Polyimide resin composition The polyimide resin composition of the present invention is characterized by containing a polyimide resin and an imide oligomer.

Polyimide resin The polyimide resin contained in the polyimide-based resin composition includes a repeating unit represented by the following general formula (1-1) and a repeating unit represented by the general formula (1-2); or is imidized. The precursor (namely, polyamic acid) which produces | generates the repeating unit shown by the following general formula (1-1) and the repeating unit shown by general formula (1-2) may be sufficient.

A ₁ in formula (1-1) and A ₂ in formula (1-2) have a triphenylene ether structure and are represented by the following formula (a1) or (a2).

A ₁ and A ₂ may be the same as or different from each other, but preferably _one of A ₁ and A ₂ is (a1) and the other is (a2). If both A ₁ and A ₂ are (a1), the desmear speed may be slow. On the other hand, when any of A ₁ and A ₂ is a (a2), it may peel strength and low-temperature adhesiveness is reduced. When A ₁ and A ₂ are a combination of (a1) and (a2), in order to balance the desmear speed and the low-temperature adhesiveness (glass transition temperature), (a1) and (a2) contained in polyimide Is preferably 8: 2 to 5: 5, more preferably 7: 3.

B ₁ and B ₂ in the formula (1) are represented by the following formula (b1) or (b2). Either one or both of B ₁ and B ₂ is preferably (b1). When B ₁ and B ₂ are a combination of formulas (b1) and (b2), the desmear rate of the resin composition is improved. On the other hand, when the ratio of (b2) is too high, the solder heat resistance in a humidified environment is increased. Sexuality may worsen.

  The polyimide resin contained in the polyimide resin composition of the present invention contains the repeating units represented by the above formulas (1-1) and (1-2), but may contain other repeating units.

  The molecular weight of the polyimide resin contained in the polyimide resin composition is not particularly limited, and is adjusted according to the molecular weight of the monomer components (diamine and tetracarboxylic dianhydride) and the molar ratio thereof, as will be described later.

Manufacture of a polyimide resin It is preferable that the polyimide resin contained in a polyimide resin composition is manufactured from the raw material containing tetracarboxylic dianhydride and diamine.

  The raw material for the polyimide resin is 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA) or bis (3,4-dicarboxyphenyl) sulfone dianhydride, which is a tetracarboxylic dianhydride. It is preferable that a product (DSDA) is included.

  Furthermore, the raw material of the polyimide resin may contain one or more other tetracarboxylic dianhydrides. By copolymerizing them, the performance of the polyimide resin can be improved or modified without impairing the effects of the present invention.

  Examples of other tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether Anhydride, bis (3,4-dicarboxyphenyl) sulfide dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis (3,4-dicarboxyphenoxy) Benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) biphenyl dianhydride, 2,2-bis [( 3,4-dicarboxyphenoxy) phenyl] propane dianhydride, etc. The

  Further examples of other tetracarboxylic dianhydrides include ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, 1,1-bis (2,3-di-). Carboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, 1,2-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,2- Bis (3,4-dicarboxyphenyl) ethane dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3 , 6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride and the like. These tetracarboxylic dianhydrides may be used alone or in combination of two or more.

  Further, other tetracarboxylic dianhydrides are tetracarboxylic acids in which some or all of the hydrogen atoms on the aromatic ring of the tetracarboxylic dianhydride exemplified above are substituted with a fluoro group or a trifluoromethyl group. A dianhydride may be sufficient.

  The raw material of the polyimide resin preferably contains 1,3-bis (3-aminophenoxy) benzene (APB) or 1,3-bis (4-aminophenoxy) benzene (APB-R) which is a diamine. More preferably, both are included.

  The raw material of the polyimide resin may contain other diamines. The other diamine may be an aromatic diamine or an aliphatic diamine.

  Examples of aromatic diamines include m-phenylene diamine, o-phenylene diamine, p-phenylene diamine, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3 '-Diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone 3,3'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2-bis (3-aminophenyl) propane, 2,2- Bis (4-aminophenyl) propane, 2,2-bis (3-aminophenyl) -1,1,1,3,3,3-hexafur Oropropane, 2,2-bis (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 3,3′-diaminodiphenyl sulfoxide, 3,4′-diaminodiphenyl sulfoxide, 4, 4'-diaminodiphenyl sulfoxide, 1,3-bis (3-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4-bis (3-aminophenyl) benzene, 1,4- Bis (4-aminophenyl) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenyl sulfide) benzene, 1,3-bis (4-aminophenylsulfide) benzene, 1,4-bis (4-aminophenylsulfide) benzene, 1,3-bis (3-aminophenylsulfone) benzene, 1,3-bis (4-aminopheny) Rusulfone) benzene, 1,4-bis (4-aminophenylsulfone) benzene, 1,3-bis (3-aminobenzyl) benzene, 1,3-bis (4-aminobenzyl) benzene, 1,4-bis ( 4-Aminobenzyl) benzene, 1,3-bis (3-amino-4-phenoxybenzoyl) benzene, 3,3′-bis (3-aminophenoxy) biphenyl, 3,3′-bis (4-aminophenoxy) Biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, bis [3- (3-aminophenoxy) phenyl] ether, bis [3- (4 -Aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, bis [3- (3-aminophenoxy) phene Ru] ketone, bis [3- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [3- (3-aminophenoxy) phenyl] sulfide, bis [3- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] Sulfide, bis [3- (3-aminophenoxy) phenyl] sulfone, bis [3- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4 -Aminophenoxy) phenyl] sulfone, bis [3- (3-aminophenoxy) phenyl] methane, bis [3- (4-aminophenoxy) pheny Ru] methane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, 2,2-bis [3- (3-aminophenoxy) phenyl] propane, 2,2-bis [3- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) Phenyl] propane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [3- (4-aminophenoxy) ) Phenyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexa Fluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hex Safluoropropane and the like are included. These aromatic diamines may be used alone or in combination.

  The raw material of the polyimide resin may contain an aliphatic diamine. Aliphatic diamines are used to improve or modify performance. Examples of aliphatic diamines include 1,3-bis (3-aminopropyl) tetramethyldisiloxane, 1,3-bis (4-aminobutyl) tetramethyldisiloxane, α, ω-bis (3-aminopropyl) ) Polydimethylsiloxane, α, ω-bis (3-aminobutyl) polydimethylsiloxane, bis (aminomethyl) ether, 1,2-bis (aminomethoxy) ethane, bis [(2-aminomethoxy) ethyl] ether, 1,2-bis [(2-aminomethoxy) ethoxy] ethane, bis (2-aminoethyl) ether, 1,2-bis (2-aminoethoxy) ethane, bis [2- (2-aminoethoxy) ethyl] Ether, bis [2- (2-aminoethoxy) ethoxy] ethane, bis (3-aminopropyl) ether, ethylene glycol bis (3-aminopropyl) ether, diethyleneglycol Rubis (3-aminopropyl) ether, triethylene glycol bis (3-aminopropyl) ether, 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, 1,2-diaminocyclohexane, 1 , 3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,2-di (2-aminoethyl) cyclohexane, 1,3-di (2-aminoethyl) cyclohexane, 1,4-di (2-aminoethyl) Cyclohexane, bis (4-aminocyclohexyl) methane, 2,6-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,5-bis ( Aminomethyl) bicyclo [2.2.1] heptane and the like. These diamines can be used alone or in combination of two or more.

  The molecular weight (degree of polymerization) of the polyimide resin contained in the polyimide resin composition of the present invention can be controlled by adjusting the molar ratio of the monomer components in the same manner as the molecular weight of a normal polycondensation polymer. That is, it is preferable that the raw material of the polyimide resin contains 0.900 mol to 0.999 mol of tetracarboxylic dianhydride with respect to 1 mol of diamine, and 0.92 to 0.995 mol of tetracarboxylic dianhydride. More preferably 0.95 to 0.995 mol of tetracarboxylic dianhydride, more preferably 0.97 to 0.995 mol of tetracarboxylic dianhydride. Further preferred.

  It is preferable that the raw material of the polyimide resin (monomer raw material containing diamine and tetracarboxylic dianhydride) is once made polyamic acid (polyimide precursor) and then made polyimide. In order to use the monomer raw material as polyamic acid, the monomer raw material may be added to a solvent and heated.

  The solvent to which the polyimide resin monomer raw material is added is not particularly limited, but is preferably an aprotic polar solvent, and more preferably an aprotic amide solvent. Specifically, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2- Examples include imidazolidinone.

  Furthermore, the solvent shown below may further coexist in the solvent to which the monomer raw material for the polyimide resin is added. Examples of organic solvents that can coexist are benzene, toluene, o-xylene, m-xylene, p-xylene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-bromotoluene, m-bromotoluene, p-bromotoluene, chlorobenzene, bromobenzene and the like are included. These organic solvents may be used alone or in combination of two or more.

  Polyamic acid produced as a polyimide precursor is used as a varnish. The logarithmic viscosity ηinh of the polyimide precursor is preferably 0.2 dl / g to 2.0 dl / g, more preferably 0.3 to 1.0 dl / g, and 0.4 to 0.9 dl / g. More preferably, it is g. The logarithmic viscosity of the polyimide precursor is the viscosity at 35 ° C. of a solution obtained by dissolving the solid content of the polyimide precursor in N, N-dimethylacetamide at a concentration of 0.5 g / dl.

  When the logarithmic viscosity of the polyimide precursor is in the above range, the cured resin obtained from the precursor becomes strong, and it becomes easy to form a film or a metal laminate. Moreover, in the coating process at the time of manufacturing a film or a metal laminate, it is preferable that the film thickness tends to be uniform.

Imide oligomer The imide oligomer contained in a polyimide-type resin composition has a structure shown by Formula (2). L in Formula (2) is 1-5. When l in Formula (2) is 1, the effect of the imide oligomer as a plasticizer is further increased, and as a result, the low-temperature adhesiveness of the polyimide resin composition is further increased.

A ₃ in the formula (2) has a structure represented by any of the following formulas (c1) to (c4). Further, A ₃ in the formula (2) preferably has a structure represented by the following formula (c5) or (c6). In the formulas (c1) to (c4), X _{7 to 12} are a direct _bond , —O—, —S—, —CO—, —COO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) _2. It is selected from the group consisting of —, —SO ₂ — and —NHCO—, and may be the same or different. X _{7 to 12} are bonded to any carbon constituting the benzene ring. Similarly, the oxygen atom in formula (c5) or (c6) is bonded to any carbon constituting the benzene ring. For example, A ₃ in Formula (2) has a structure represented by Formula (C7) or Formula (C8).

B ₃ in the formula (2) has a structure represented by any of the following formulas (d1) to (d4). Furthermore, B ₃ in Formula (2) preferably has a structure represented by Formula (d1) or any of (d5) to (d10). The structure of B ₃ may be selected from the viewpoint of solvent solubility and cost. In formulas (d1) to (d4), Y _{7 to 12} are a direct _bond , —O—, —S—, —CO—, —COO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) _2. It is selected from the group consisting of —, —SO ₂ — and —NHCO—, and may be the same or different. _Y7-12 is couple _| bonded with either of the carbon atoms which comprise a benzene ring. The _{Y 7 to 12} are, if it is -COO- or -NHCO-, the orientation of the coupling may be any.

Z in the formula (2) is represented by the following formula (e1) or (e2), and more preferably represented by the following formula (e3) or (e4). In Formula (e1), Formula (e2), or Formula (e4), _R1-4 are selected from the group consisting of a hydrogen atom, a halogen atom, and an alkyl group having 1 to 3 carbon atoms, and may be the same or different from each other It may be. In the formula (e4), R ₃ and R ₄ are preferably a hydrogen atom. R ₅ represents —O—, —S—, —CH ₂ —, —C (CH ₃ ) ₂ —, —CO—, or —COO—. When R ₅ is —COO—, the direction of the bond may be any.

The imide oligomer contained in the polyimide resin composition of the present invention preferably has a weight average molecular weight (also referred to as Mw) of 1000 or more and 5000 or less. The weight average molecular weight of the imide oligomer is measured by gel permeation chromatography (measurement conditions, detector; RI, developing solvent; tetrahydrofuran, flow rate; 1 ml / min, column temperature; 40 ° C.).
When the weight average molecular weight of the imide oligomer is within this range, the amount of evaporation when the resin composition is heated is reduced, and the plasticizing effect is not deteriorated. Furthermore, from the viewpoint of the balance between evaporation suppression and plasticity improvement, the weight average molecular weight Mw is preferably 1000 or more and 4000 or less, more preferably 1000 or more and 3500 or less, and further preferably 1500 or more and 3500 or less. .

Production method of imide oligomer The imide oligomer contained in the polyimide resin composition of the present invention can be produced by any method, for example, tetracarboxylic dianhydride, diamine and dicarboxylic anhydride, and, if necessary, a solvent. It is produced by imidizing a raw material containing A preferable imide oligomer is obtained by controlling the molar ratio of each component (tetracarboxylic dianhydride, diamine and dicarboxylic anhydride) contained in the raw material (described later).

  Examples of the tetracarboxylic dianhydride contained in the raw material of the imide oligomer include pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4, 4′-benzophenonetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfide dianhydride, bis (3,4-dicarboxyphenyl) ) Sulfone dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4- Dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3 , 4-Dicarboxyphenoxy) benzene dianhydride, 1,4-bis 3,4-dicarboxyphenoxy) biphenyl dianhydride, and the like 2,2-bis [(3,4-dicarboxyphenoxy) phenyl] propane dianhydride. The tetracarboxylic dianhydride contained in the raw material of the imide oligomer is one or more.

  Examples of diamines contained in imide oligomer raw materials include m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, and 4,4′-diamino. Diphenyl ether, 3,3′-diaminodiphenyl sulfide, 3,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfide, 3,3′-diaminodiphenyl sulfone, 3,4′-diaminodiphenyl sulfone, 4,4 '-Diaminodiphenylsulfone, 3,3'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2-bis (3-aminophenyl) propane 2,2-bis (4-aminophenyl) propane, 2,2-bis (3-aminophenyl)- 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 3,3′-diamino Diphenyl sulfoxide, 3,4′-diaminodiphenyl sulfoxide, 4,4′-diaminodiphenyl sulfoxide, 1,3-bis (3-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 1,4 -Bis (3-aminophenyl) benzene, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, , 4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenyl sulfide) benzene, 1,3-bis (4-aminophenyl sulfide) ) Benzene, 1,4-bis (4- Aminophenylsulfide) benzene, 1,3-bis (3-aminophenylsulfone) benzene, 1,3-bis (4-aminophenylsulfone) benzene, 1,4-bis (4-aminophenylsulfone) benzene, 3-bis (3-aminobenzyl) benzene, 1,3-bis (4-aminobenzyl) benzene, 1,4-bis (4-aminobenzyl) benzene, 1,3-bis (3-amino-4-phenoxy) Benzoyl) benzene, 3,3′-bis (3-aminophenoxy) biphenyl, 3,3′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4 ′ -Bis (4-aminophenoxy) biphenyl, bis [3- (3-aminophenoxy) phenyl] ether, bis [3- (4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) Phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, bis [3- (3-aminophenoxy) phenyl] ketone, bis [3- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [3- (3-aminophenoxy) phenyl] sulfide, bis [3- (4-aminophenoxy) phenyl] Sulfide, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [3- (3-aminophenoxy) phenyl] sulfone, bis [3- (4 -Aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) ) Phenyl] sulfone, bis [3- (3-aminophenoxy) phenyl] methane, bis [3- (4-aminophenoxy) phenyl] methane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4 -(4-Aminophenoxy) phenyl] methane, 2,2-bis [3- (3-aminophenoxy) phenyl] propane, 2,2-bis [3- (4-aminophenoxy) phenyl] propane, 2,2 -Bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3- (3-aminophenoxy) phenyl]- 1,1,1,3,3,3-hexafluoropropane, 2,2-bis [3- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 2, , 2-Bis [4- (3-aminophenoxy) phenyl -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, etc. Is included. One or more diamines are contained in the raw material of the imide oligomer.

  Examples of the dicarboxylic acid anhydride contained in the raw material of the imide oligomer include maleic anhydride and nadic anhydride. Alternatively, it may be a compound that forms a benzene ring by trimerization, such as 4- (2-phenylethynyl) phthalic anhydride and 4- (2-ethynyl) phthalic anhydride.

  The solvent contained in the raw material of the imide oligomer is preferably an organic solvent. Examples of the organic solvent include phenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-cresol, m-cresol, p -Cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, N, N-dimethylformamide, N, N- Dimethylacetamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, 1,2-dimethoxyethane, Bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, bis [2- (2-methoxyethoxy) ethyl] ether, Tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, pyridine, picoline, dimethyl sulfoxide, dimethyl sulfone, tetramethylurea, hexamethylphosphoramide, and the like anisole. These organic solvents may be used alone or in combination of two or more.

  The following solvent may coexist in the raw material of the imide oligomer. Examples of organic solvents that can coexist are benzene, toluene, o-xylene, m-xylene, p-xylene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-bromotoluene, m-bromotoluene, p-bromotoluene, chlorobenzene, bromobenzene and the like are included.

The raw material of the imide oligomer may contain a catalyst for increasing the speed of the imidization reaction (described later), for example, an organic base catalyst. Examples of organic base catalysts include triethylamine, tributylamine, tripentylamine, N, N-dimethylaniline, N, N-diethylaniline, pyridine, α-picoline, β-picoline, γ-picoline, 2,4-lutidine 2,6-lutidine, quinoline, isoquinoline and the like are included, and pyridine and γ-picoline are preferable.
The content of the catalyst in the raw material of the imide oligomer is not particularly limited as long as the polymerization reaction rate can be substantially improved, but for example, 0.001 to 0.5 mol with respect to 1 mol of tetracarboxylic dianhydride. is there.

  As a procedure for producing an imide oligomer, (1) after reacting diamine and tetracarboxylic dianhydride, add dicarboxylic anhydride and continue the reaction, or (2) add diamine and dicarboxylic anhydride. After the reaction, the tetracarboxylic dianhydride component is added and the reaction is continued, or (3) the diamine compound, tetracarboxylic dianhydride and dicarboxylic anhydride are added and reacted at the same time. Any procedure may be used.

Examples of imidization reactions include thermal imidization, chemical imidization, and direct thermal imidization.
Thermal imidation is the reaction of the aforementioned raw materials at a low temperature of 100 ° C. or lower, specifically −20 to 70 ° C., preferably 0 to 60 ° C., to synthesize an imide oligomer precursor, and then to 100 to 200 ° C. This is a method for obtaining an imide oligomer by raising the temperature and imidizing. Chemical imidation is a method in which the imide oligomer precursor is chemically imidized using an imidizing agent such as acetic anhydride.
On the other hand, direct thermal imidation refers to mixing diamine, tetracarboxylic dianhydride and dicarboxylic anhydride and then quickly raising the temperature in the presence or absence of an organic base and / or azeotropic dehydration solvent. Thus, the imide oligomer precursor generated in the reaction system is imidized as it is.

The reaction time for imidation varies depending on the type of monomer used, the type of solvent, the type of organic base catalyst, the type and amount of azeotropic dehydration solvent, and the reaction temperature, but it is generally 1 to 24 hours. Is a few hours.
In the case of direct thermal imidation, as a guideline, the reaction is carried out until the distilled water reaches a theoretical amount (usually, not all are recovered, so the recovery rate is 50 to 90%). Approximately several hours of reaction time are required. In this case, a method of removing water generated by imidization with an azeotropic agent such as toluene is common and effective.

  The reaction pressure for imidization is not particularly limited, but may usually be atmospheric pressure. The imidization reaction is usually performed in an atmosphere of air, nitrogen, helium, neon, or argon, preferably in an atmosphere of nitrogen or argon as an inert gas, but is not particularly limited.

  The concentration (polymerization concentration) of the monomer component contained in the raw material of the imide oligomer is not particularly limited, but is generally about 10 to 60 wt%. When the amount is less than 10 wt%, an extremely long reaction time may be required. When the amount exceeds 60 wt%, the raw material becomes difficult to dissolve and the reaction efficiency may be deteriorated. The polymerization concentration is preferably 20 to 50 wt%, more preferably 30 to 40 wt%.

The molecular weight of the imide oligomer can be controlled by adjusting the molar ratio of the monomer components contained in the raw material, as in the case of the molecular weight of a normal polycondensation polymer. It is important that the raw material of the imide oligomer contains 0.50 to 0.80 mol of tetracarboxylic dianhydride with respect to 1 mol of diamine, more preferably 0.50 to 0.70 mol, More preferably, 0.50 to 0.65 mol, and still more preferably 0.50 to 0.60 mol of tetracarboxylic dianhydride is contained. By controlling the ratio of the monomer components as appropriate, an imide oligomer having a preferred molecular weight can be produced as described above.
If the tetracarboxylic dianhydride is less than 0.5 mol relative to 1 mol of diamine, a large amount of bisimide composed of diamine and dicarboxylic anhydride is generated, and the amount of evaporation during heating increases, which is not preferable. On the other hand, if it exceeds 0.80 mol, the plasticizing effect when used, for example, as a plasticizer decreases due to an increase in molecular weight, which is not preferable.

Moreover, it is important that the number of moles M5 of the dicarboxylic acid anhydride contained in the raw material of the imide oligomer satisfies the relationship of the following mathematical formula with the number of moles M3 of the tetracarboxylic dianhydride and the number of moles M4 of the diamine. .
(M4-M3) × 2 × 1.0 ≦ M5 ≦ (M4-M3) × 2 × 2.2

  Preferably, the relationship of (M4-M3) × 2 × 1.0 ≦ M5 ≦ (M4-M3) × 2 × 2.0 is satisfied, and more preferably, (M4-M3) × 2 × 1.0 ≦ M5 ≦ (M4-M3) × 2 × 1.5, more preferably (M4-M3) × 2 × 1.0 ≦ M5 ≦ (M4-M3) × 2 × 1.2 .

  When (M4-M3) × 2 × 1.0> M5, an amino group remains in the imide oligomer to be produced, and it is colored upon heating, which is not preferable in appearance. On the other hand, if (M4-M3) × 2 × 2.2 <M5, a large amount of bisimide composed of diamine and dicarboxylic acid anhydride is generated, and the amount of evaporation during heating increases, which is not preferable.

Polyimide-based resin composition The polyimide-based resin composition of the present invention includes a polyimide resin containing a repeating unit represented by the general formula (1-1) and a repeating unit represented by the general formula (1-2), and the general It includes an imide oligomer represented by the formula (2). Further, even if the polyimide resin is a cured resin, it is a resin (polyamide acid) that generates a repeating unit represented by the general formula (1-1) and a repeating unit represented by the general formula (1-2) when cured. ).

The polyimide resin composition preferably contains 5 parts by weight or more and 100 parts by weight or less of the imide oligomer represented by the general formula (2) with respect to 100 parts by weight of the polyimide resin. More preferably, it is contained in an amount of 20 parts by weight or less and more preferably 80 parts by weight or less.
When the ratio between the polyimide resin and the imide oligomer is within the above range, the glass transition temperature of the polyimide resin composition becomes sufficiently low, which is particularly useful when used for a metal laminate requiring low-temperature adhesion. Furthermore, when the polyimide resin composition is cured to form a film or layer, the brittleness thereof is reduced, which is preferable.

  When the polyimide resin composition of the present invention is cured and used as a resin layer for a laminate for a flexible circuit board or an adhesive sheet, the glass transition temperature of the polyimide resin composition is in the range of 100 ° C. or more and 300 ° C. or less. It is preferable that Furthermore, it is preferable that it is 100-240 degreeC from a viewpoint of implement | achieving adhesion | attachment on low temperature conditions, and it is more preferable that it is 100-200 degreeC.

The polyimide resin composition of the present invention may contain other arbitrary thermoplastic resins and thermosetting resins as long as the object of the present invention is not impaired.
Examples of optional thermoplastic resins include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polybutadiene, polystyrene, polyvinyl acetate, ABS resin, polybutylene terephthalate, polyethylene terephthalate, polyphenylene oxide, polycarbonate, PTFE, celluloid, poly Examples include arylate, polyether nitrile, polyamide, polysulfone, polyether sulfone, polyether ketone, polyphenylene sulfide, polyamide imide, polyether imide, modified polyphenylene oxide, and polyimide.
Examples of optional thermosetting resins include thermosetting polybutadiene, formaldehyde resin, amino resin, polyurethane, silicone resin, SBR, NBR, unsaturated polyester, epoxy resin, polycyanate, phenolic resin and polybismaleimide It is.
Depending on the purpose, one or two or more thermoplastic resins or thermosetting resins can be blended or alloyed in an appropriate amount and contained in the polyimide resin composition. Those methods are not particularly limited, and known methods can be applied.

  Various kinds of fillers or additives may be mixed in the polyimide resin composition as long as the object of the present invention is not impaired. Examples of fillers or additives include wear resistance improvers such as graphite, carborundum, silica stone powder, molybdenum disulfide, and fluorine resins; flame retardant improvers such as antimony trioxide, magnesium carbonate, calcium carbonate; Electrical property improvers such as clay and mica; Tracking resistance improvers such as asbestos, silica and graphite; Acid resistance improvers such as barium sulfate, silica and calcium metasilicate; Iron powder, zinc powder, aluminum powder, copper powder, etc. In addition, glass beads, glass spheres, talc, diatomaceous earth, alumina, shirasu balun, hydrated alumina, metal oxides, colorants and pigments are included. A mixing method is not particularly limited, and a known method can be applied.

  The polyimide resin composition of the present invention comprises a polyamic acid (polyimide precursor) containing a repeating unit represented by the general formula (3-1) and a repeating unit represented by the general formula (3-2), The solution containing the imide oligomer represented by the general formula (2) can be obtained by imidizing polyamic acid and reacting the imide oligomer. The imide oligomer is irreversibly polymerized by polymerization of terminal double bonds. The polymer of an imide oligomer can be detected by confirming the presence of a double bond by IR.

  In particular, a film or a layered polyimide resin can be obtained by heating and drying a coating film of a solution containing polyamic acid (polyimide precursor) and an imide oligomer to remove the solvent and curing by imidization reaction. A cured product can be obtained.

  The solvent of the solution containing the polyamic acid and the imide oligomer is not particularly limited, but is preferably an aprotic polar solvent. More preferred are aprotic amide solvents, specifically, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, N-methyl- Examples thereof include 2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone.

  The viscosity of the solution containing the polyamic acid and the imide oligomer is not particularly limited. For example, when the viscosity measured at 25 ° C. using an E-type viscometer is in the range of 100 to 20000 mPa · S, the coating thickness can be easily controlled when the solution is applied.

  When the solution containing the polyamic acid and the imide oligomer is heat-treated, imidization of the polyamic acid or a reaction between the imide oligomers occurs, and a cured polyimide resin is obtained. As the pressure in the heat treatment, atmospheric pressure is usually sufficient, but it can also be performed under pressure. The heat treatment atmosphere is not particularly limited, but is usually air, nitrogen, helium, neon, or argon, and preferably inert gas such as nitrogen or argon.

Further, an additive such as a catalyst may be added to the solution containing the polyamic acid and the imide oligomer for the purpose of accelerating or suppressing the crosslinking reaction that proceeds by the heat treatment or controlling the reaction rate. Examples of catalysts include metal catalysts containing gallium, germanium, indium or lead; transition metal catalysts including molybdenum, manganese, nickel, cadmium, cobalt, chromium, iron, copper, tin or platinum; and phosphorus compounds, silicon Compounds, nitrogen compounds or sulfur compounds are included.
For the same purpose, the solution containing the polyamic acid and the imide oligomer is irradiated with radiation such as infrared rays, ultraviolet rays, α, β and γ rays, electron beams and X-rays, and further plasma treatment and doping treatment. It can also be applied.

The polyimide resin composition of the present invention may be a film. In order to form a film, a solution containing polyamic acid and an imide oligomer is applied to a substrate, and the obtained coating film is cured by desolvation and imidization, and then peeled off from the substrate. Good. Examples of the substrate include inorganic substrates such as metal foil and glass, or polymer films. Moreover, what is necessary is just to perform the coating to a base material using a coater. The coating thickness is affected by the solid content concentration of the solution containing the polyamic acid and the imide oligomer, but the thickness of the cured polyimide resin film after desolvation and imidization reaction (that is, “after curing”). Is preferably 1 mm or less.
There is no particular limitation on the method of desolvation and imidization (that is, “curing”), but it may be performed under reduced pressure or in an inert atmosphere such as nitrogen, helium, or argon. Moreover, what is necessary is just to be more than the boiling point of the solvent to be used, and more than the temperature which an imidation reaction advances. For example, when an aprotic amide solvent is used, it may be 200 degreeC or more. The time required for solvent removal and imidization is not particularly limited, but usually 2 hours or more is sufficient.

2. Metal Laminate The metal laminate of the present invention includes a metal layer and a resin layer. The metal laminate includes one or two or more resin layers, and one or more of the resin layers are formed from a cured product (also referred to as “resin cured product”) of the polyimide resin composition of the present invention. Become. Preferably, the metal laminate has a polyimide film, a polyimide layer formed on one or both sides of the polyimide film, and a metal layer laminated on one or both of the polyimide layers, and is in contact with the metal layer. A polyimide layer consists of the hardened | cured material of the polyimide resin composition of the above-mentioned this invention.

Resin layer As described above, the metal laminate of the present invention includes one or two or more polyimide resin layers, and one or more of the resin layers are made of a cured product of the polyimide resin composition of the present invention. . When two or more polyimide resin layers are included, adjacent layers are preferably made of polyimides having different components. Different polyimide components mean different types and / or contents of monomer units. Moreover, at least one of the layers constituting the single-layer polyimide layer or the multilayer polyimide layer may be formed from a composition (mixture) composed of two or more different polyimides.

  That is, when the polyimide layer which comprises a metal laminated body is a single layer, the layer consists of the hardened | cured material of the polyimide resin composition of this invention. On the other hand, when the polyimide layer constituting the metal laminate is a multilayer, among the polyimide layers formed on one or both sides of the polyimide film, the polyimide layer in contact with the metal layer is made of the polyimide resin composition of the present invention. A layer made of a cured product is preferred. This is to improve the adhesion with the metal layer. The thickness of the polyimide layer in contact with the metal layer is 0.1 μm or more and 20 μm or less, preferably 0.1 μm or more and 10 μm or less, more preferably 0.1 μm or more and 5 μm or less.

  In addition, if the total thickness of the polyimide layer (single layer or multilayer) constituting the metal laminate becomes too thick, the rigidity becomes so strong that it cannot be used for applications that require bending, etc. If it is too thin, insulation and handling are difficult. There is a restriction that it can no longer be used.

  Therefore, the total thickness of the polyimide layers contained in the metal laminate is preferably 3 μm or more and 75 μm or less, and more preferably 10 μm or more and 45 μm or less. When the thickness of the polyimide layer is within the above range, the metal laminate tends to be excellent in insulation, flexibility, workability, and inexpensive.

Polyimide film As described above, the metal laminate may have a polyimide film, a polyimide layer formed on one or both sides of the polyimide film, and a metal layer laminated on either or both of the polyimide layers. The polyimide film contained in the metal laminate may be a film obtained by applying and drying a precursor varnish of non-thermoplastic polyimide, or a commercially available non-thermoplastic polyimide film. Examples of commercially available non-thermoplastic polyimide films include Upilex S, Upilex SGA, Upilex SN (Ube Industries, registered trademark / trade name), Kapton H, Kapton V, Kapton EN (Toray DuPont, Registered trademark / brand name), Apical AH, Apical NPI, Apical HP (manufactured by Kaneka Corporation, registered trademark / brand name), and the like.

  When the polyimide film contained in the metal laminate is a commercially available non-thermoplastic polyimide film, the thickness is usually 3 μm or more and 75 μm or less, preferably 7.5 μm or more and 40 μm or less. When the polyimide film is formed by applying and drying a precursor varnish of non-thermoplastic polyimide, the thickness is 0.1 μm or more and 40 μm or less, preferably 0.5 μm or more and 25 μm or less, more preferably 0.8. It is 5 μm or more and 16 μm or less.

Metal layer The metal layer included in the metal laminate is not particularly limited, but is a metal layer selected from copper and copper alloys, stainless steel and alloys thereof, nickel and nickel alloys (including 42 alloys), aluminum and aluminum alloys, and the like. Yes, preferably a copper or copper alloy layer or a stainless steel layer. The metal layer may be formed by attaching a metal foil to the resin layer, or may be formed on the resin by a sputtering method or the like, and can be formed using a known means. The metal layer is preferably in contact with the resin layer made of the polyimide resin composition of the present invention.

  The thickness of the metal layer contained in the metal laminate is not particularly limited as long as the metal laminate can be used as a tape, and is usually 0.1 μm or more and 150 μm or less, preferably 2 μm or more and 150 μm or less. More preferably, it is 3 μm or more and 50 μm or less, more preferably 3 μm or more and 35 μm or less, and most preferably 3 μm or more and 12 μm or less.

Method for Producing Metal Laminate The metal laminate of the present invention can be produced by appropriately referring to a known method for producing a metal laminate as long as the effects of the present invention are not impaired, and is not particularly limited. For example, it can be produced by the following method. (1) A method in which a single-layer or multilayer polyimide film and a metal foil are thermocompression bonded. (2) A method in which a varnish of a polyimide resin composition is applied to a metal foil and then dried. (3) Laminate the following laminate (i) or laminate (ii) and the following laminate (i) or laminate (ii) so that the metal layer is the outermost layer (the resin layers are in contact with each other) And stacking together).
Laminate (i): A laminate having a metal layer only on one surface obtained by thermocompression bonding a single-layer or multilayer polyimide film and a metal foil.
Laminate (ii): A laminate having a metal layer only on one surface obtained by applying a varnish of a polyimide resin composition to a metal foil and then drying.

  The metal foil used for the production of the metal laminate is not particularly limited, and known ones can be used. Examples of metal foil materials include copper and copper alloys, stainless steel and alloys thereof, nickel and nickel alloys (including 42 alloys), aluminum and aluminum alloys, preferably copper or copper alloys, or stainless steel. is there. The thickness of the metal foil is not particularly limited as long as it can be used in the form of a tape, but is usually 0.1 μm or more and 150 μm or less, preferably 2 μm or more and 150 μm or less, more preferably 3 μm or more and 50 μm or less, and further preferably The range is 3 μm or more and 35 μm or less, and most preferably 3 μm or more and 12 μm or less. When manufacturing a metal laminated body, the surface of the polyimide layer to which metal foil is pressure-bonded may be subjected to plasma treatment or corona discharge treatment.

The thermocompression bonding at the time of producing the metal laminate of the present invention includes a method of laminating between a metal roll heated by heating using an oil or the like or a dielectric heating, or a roll having a metal roll surface lined with rubber or the like. Or by a method using a heat press. The former is suitable for the production of continuous roll products, and the latter is suitable for the production of cut sheet-like single-sheet products, and can be used according to the intended use.
The thermocompression bonding may be performed in a gas atmosphere such as air, nitrogen, or argon. The heating temperature needs to be a temperature higher than the glass transition temperature of the thermoplastic polyimide, preferably about 20 ° C. higher than the glass transition temperature, and is usually between 100 and 400 ° C., preferably between 150 and 300 ° C. Just do it. Moreover, it is preferable that heating time is 0.01 second or more and 15 hours or less, and heating pressure should just be the range of 0.1-30 MPa, and is 0.5-10 MPa normally.

  In addition, after thermocompression bonding, for the purpose of further improving the adhesion of the metal laminate, post-treatment may be performed using an autoclave or the like. Post-processing is performed under the following conditions. The post-treatment temperature is usually 150 to 400 ° C., preferably 200 to 350 ° C., the treatment time is 1 minute to 50 hours, and the pressure is in the range of normal pressure to 3 MPa. It is preferable to prevent oxidation of the metal foil by replacing the inside of the autoclave apparatus with an inert gas such as vacuum, nitrogen or argon.

  In the method for producing a metal laminate of the present invention, when a varnish of polyimide resin composition (solution containing polyamic acid and imide oligomer) is applied to a metal foil, a roll coater, a die coater, a gravure coater, a dip coater, The coating can be performed using a general coating apparatus such as a spray coater, a comma coater, a curtain coater, a bar coater, etc., and can be appropriately selected according to the viscosity and coating thickness of the varnish.

Drying of the applied varnish of the polyimide resin composition can be carried out by appropriately using a roll support using an electric heating, oil heated hot air, infrared rays or the like as a heat source, an air float type drying furnace or the like. For the purpose of preventing deterioration of the resin and discoloration due to oxidation of the metal foil, the dry atmosphere may be replaced with a gas such as nitrogen, argon or hydrogen in addition to air, if necessary.
It is preferable to dry the varnish of the applied polyimide resin composition in a temperature range of 60 to 600 ° C., preferably by increasing the temperature stepwise. It is possible to prevent foaming from the coating film during drying or unevenness on the surface of the film after drying, and a resin film having a uniform film thickness and excellent dimensional stability can be obtained. Preferred for formation. The drying time may be appropriately selected from about 0.05 to 500 minutes.

Adhesive sheet The adhesive sheet of this invention has a resin film and the resin layer which consists of a hardened | cured material of the resin composition of this invention formed in the single side | surface or both surfaces of the film. As the resin film, a known resin film can be exemplified, and the type is not particularly limited, but the above-described polyimide film can be preferably exemplified. The method for forming the resin layer on one or both sides of the resin film is not particularly limited, but preferably, as shown in the method for producing a metal laminate, a varnish of a polyimide resin composition is applied and dried. Can be formed.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The scope of the present invention is not construed as being limited thereby.

  In Examples and Comparative Examples, each physical property was measured by the following method.

Evaluation of polyamic acid 1) Logarithmic viscosity (ηinh): Polyamic acid varnish was added to N, N-dimethylacetamide solvent to adjust the solid content concentration to 0.5 g / dl, and then set to 35 ° C. Measured in the bath.
2) E-type viscosity: Measured with a 3 ° cone rotor using an E-type viscometer (RC-105A, Toki Sangyo Co., Ltd.) at a constant temperature of 25 ° C.

Evaluation of Imide Oligomer 1) Logarithmic viscosity (ηinh): Imide oligomer was added to N, N-dimethylacetamide solvent to adjust imide oligomer solid content concentration to 0.5 g / dl. The solution was adjusted to 35 ° C. and the logarithmic viscosity was measured.
2) Molecular weight (weight average molecular weight Mw, number average molecular weight Mn): measured using Shodex GPCsystem-21H series (detector; RI, developing solvent; tetrahydrofuran, flow rate; 1 ml / min, column temperature; 40 ° C.) .
3) Glass transition temperature (Tg): Measured under a nitrogen atmosphere using a thermal analyzer DSC60 series manufactured by Shimadzu Corporation.

Evaluation of Polyimide Resin Composition 1) Glass transition temperature (Tg): Measured under a nitrogen atmosphere using a thermal analyzer DSC60 series manufactured by Shimadzu Corporation.
2) Desmear speed: A polyamic acid solution was coated on a glass plate and heated at 300 ° C. for 4 hours under a nitrogen atmosphere to prepare a polyimide film. A sample having a size of 6 × 2 cm ² was cut out and used as a measurement sample. The etchant was prepared by mixing 50 g of Macuizer 9275 (manufactured by McDermid Japan), 50 ml of Macuitizer 9276 (manufactured by McDermid Japan) and ion-exchanged water so that the total amount was 1 L. The sample was immersed in an etching solution for 15 minutes, washed with water, dried, and calculated from the weight change before and after immersion.
3) Volatility: A solution was prepared by adding 33 parts by weight of an imide oligomer to 100 parts by weight of polyamic acid solids in a polyamic acid varnish, and cast onto a glass substrate. The film obtained by heating at 240 ° C. for 15 minutes in a nitrogen atmosphere was peeled off and cut into 5 cm squares. This film was put in a petri dish, heated at 280 ° C. for 30 minutes in a nitrogen atmosphere, and cooled to room temperature. The amount of deposits adhering to the petri dish upper lid was visually observed and evaluated on the basis of ◯ (no deposits), Δ (slightly deposits), and x (almost all deposits).

Evaluation of metal laminate 1) Peel strength: measured in accordance with JIS C-6471. Prepare a sample with a length of 50 mm and a width of 1 mm parallel to the flow direction of the metal foil, and peel the metal foil from the insulating layer at an angle of 90 degrees in an environment of 23 ° C. and 50% relative humidity. Peeling was performed at a speed of 50 mm / min, and the stress was measured.
2) Solder heat resistance temperature: IPC-TM-650 (The institute for Interconnecting and Packaging Electronic Circuits) No. Measured according to 2.4.13. The highest temperature at which no swelling or discoloration of the metal / polyimide interface occurs between 240 ° C. and 340 ° C. every 10 ° C. was defined as the solder heat resistance temperature. The sample used was stored for 48 hours in an environment of 85 ° C. and 85% relative humidity.

  The chemical structure was confirmed using a JEOL nuclear magnetic resonance (NMR) apparatus EX400.

Abbreviations of solvents, diamines, tetracarboxylic dianhydrides, and dicarboxylic anhydrides used in Examples and Comparative Examples are as follows.
1) Solvent:
DMAc: N, N-dimethylacetamide 2) Diamine:
APB: 1,3-bis (3-aminophenoxy) benzene,
APB-R: 1,3-bis (4-aminophenoxy) benzene,
m-BP: 4,4′-bis (3-aminophenoxy) biphenyl,
3) Tetracarboxylic dianhydride BTDA: 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride,
DSDA: bis (3,4-dicarboxyphenyl) sulfone dianhydride,
ODPA: bis (3,4-dicarboxyphenyl) ether dianhydride,
BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride,
PMDA: pyromellitic dianhydride,
4) Dicarboxylic anhydride:
MA: maleic anhydride NDA: nadic anhydride

[Synthesis Example 1-1]
Synthesis of polyamic acid varnish After charging DMAc (991 g) as a solvent into a vessel equipped with a stirrer and a nitrogen introduction tube, APB (146.25 g) and APB-R (61.39 g) were charged into the container. Stir at room temperature until dissolved. Next, BTDA (219.92 g) was charged and stirred at 50 ° C. for 6 hours to obtain a polyamic acid varnish.
The obtained polyamic acid varnish had a polyamic acid solid content of 30 wt%, a logarithmic viscosity of 0.61 dl / g, and an E-type viscosity at 25 ° C. of 13000 mPa · S.

[Synthesis Examples 1-2 to 1-15]
A polyamic acid varnish was synthesized in the same manner as in Synthesis Example 1, except that the tetracarboxylic dianhydride, the type of diamine, and the molar ratio were changed to those shown in Table 1. The results are shown in Table 1 together with Synthesis Example 1.

[Synthesis Example 2-1]
Synthesis of imide oligomer APB (29.23 g, 0.10 mol), ODPA (15.51 g, 0.05 mol), maleic anhydride (maleic anhydride) was added to a flask equipped with a stirrer, nitrogen inlet tube, Dean Stark, condenser and thermometer. Hereinafter, MA) (11.77 g, 0.12 mol), DMAc (132 g) as a solvent, and toluene (42 g) as a dehydrating azeotropic solvent were charged. The solution was then stirred and heated to 130-135 ° C. while passing nitrogen gas. As the internal temperature reached around 130 ° C., evaporation of toluene and water occurred. A part of them is condensed in a cooler, water and toluene are separated by Dean Stark, then only toluene is refluxed into the system, and a part of the nitrogen gas is circulated from the upper part of the cooling pipe to the outside of the system. did.

  After reacting for 7 hours, the reaction vessel was cooled to stop the polymerization reaction. The reaction mixture was charged into methanol to precipitate an imide oligomer, and then washed with methanol. Thereafter, it was dried at 90 ° C. for 12 hours under a nitrogen flow to obtain 39.59 g of an imide oligomer (yield 78%). The obtained imide oligomer has a logarithmic viscosity ηinh of 0.07 dl / g, a GPC measurement number average molecular weight (hereinafter referred to as Mn) of 2100, a weight average molecular weight (hereinafter referred to as Mw) of 3100, and a polydispersity Mw / Mn was 1.5.

  In order to confirm the structure of the obtained imide oligomer, the formation of an imide oligomer having the target structure was confirmed by NMR and FD-MS measurements. The imide oligomer had a Tg of 118 ° C. as measured by DSC. When this imide oligomer was mixed with DMAc at a concentration of 40 wt% at room temperature, it quickly dissolved.

[Synthesis Examples 2-2 to 2-7]
An imide oligomer was synthesized and evaluated in the same manner as in Synthesis Example 16 except that the types of tetracarboxylic dianhydride and diamine were changed to those shown in Table 2. The results are shown in Table 2 together with Synthesis Example 2-1.

[Synthesis Example 2-8]
In a flask equipped with a stirrer, nitrogen inlet tube, Dean Stark, condenser and thermometer, APB (29.23 g, 0.10 mol), ODPA (15.51 g, 0.05 mol), NDA (9.85 g, 0.00). 06 mol) and DMAc (163 g) as solvent.
The resulting solution was stirred and heated to 160 ° C. while passing nitrogen gas. As the internal temperature reached around 160 ° C., a small amount of DMAc and water evaporated. A part of them was condensed in a cooler and extracted from the Dean Stark, and a part was distilled out of the system from the top of the cooling pipe together with the flowing nitrogen gas. After 2 hours, NDA (9.85 g, 0.06 mol) was charged into the reactor and heated for an additional 4 hours. Thereafter, the reaction vessel was cooled to stop the polymerization reaction.

  The reaction mixture was charged into methanol to precipitate an imide oligomer and washed with methanol. The washed product was dried for 12 hours at 90 ° C. under a nitrogen flow to obtain 41.81 g of an imide oligomer (yield 73%). The resulting imide oligomer has a logarithmic viscosity ηinh of 0.07 dl / g, a GPC measurement number average molecular weight Mn of 1500, a weight average molecular weight Mw of 2100, and a polydispersity Mw / Mn that is an index of molecular weight distribution is 1.4. there were.

  In order to confirm the structure of the imide oligomer, the formation of an imide oligomer having the target structure was confirmed by NMR and FD-MS measurements. Tg by DSC measurement of the imide oligomer was 120 ° C. When this imide oligomer was mixed with DMAc at a concentration of 40 wt% at room temperature, it quickly dissolved.

[Synthesis Examples 2-9 to 2-14]
An imide oligomer was synthesized and evaluated in the same manner as in Synthesis Example 2-6 except that the types of tetracarboxylic dianhydride and diamine were changed to those shown in Table 2. The results are summarized in Table 2.

[Synthesis Examples 2-15 and 2-16]
Synthesis of bisimide Synthesis and evaluation were carried out by the method described in JP-A-4-99764. The results are summarized in Table 2.

[Example 1]
The polyamide in the polyamic acid varnish was prepared by adding the polyamic acid varnish obtained in Synthesis Example 1-1 and the imide oligomer obtained in Synthetic Example 2-1 to a flask equipped with a stirrer, a nitrogen introduction tube and a thermometer. The imide oligomer was 33 parts by weight with respect to 100 parts by weight of the acid solid content.
The mixture was heated to 40 ° C. and mixed, and DMAc was charged to obtain a light brown transparent solution having a viscosity of 100 to 1000 in an E-type viscometer. The film obtained by casting the obtained solution had a Tg of 177 ° C. Moreover, the desmear speed | rate measured in accordance with the above-mentioned procedure was 2ug / cm < ² > / min, and the evaluation of the volatility test was (circle).

  Next, the above solution was applied to both sides of a commercially available polyimide resin film (trade name: Kapton 100EN, manufactured by Toray DuPont Co., Ltd.) using a roll coater, and 70 ° C. for 5 minutes, 100 ° C. for 2 minutes, 140 ° C. For 2 minutes, 180 ° C. for 2 minutes, and 220 ° C. for 10 minutes, and the thickness after drying was 4 μm. In this way, a polyimide insulating film having a polyimide resin cured material layer laminated on both surfaces of the resin film was obtained.

  A roll laminator in which a copper foil (manufactured by Furukawa Circuit Foil Co., Ltd., trade name: F1-WS, thickness 9 μm) is directly stacked on the polyimide resin cured layer of the obtained polyimide insulating film and covered with silicon rubber. Thus, bonding was performed at 240 ° C. under a pressure of 1.4 MPa. Thereafter, annealing was performed for 4 hours in a batch autoclave at a temperature of 320 ° C. in a nitrogen atmosphere to obtain a polyimide metal laminate. The peel strength of the polyimide metal laminate was 1.0 kN / m, and the solder heat resistance temperature was 340 ° C.

[Examples 2 to 29]
A polyimide resin composition was synthesized and evaluated in the same manner as in Example 1 except that the types of polyamide acid varnish and imide oligomer were changed as shown in Table 3A or Table 3B, and a polyimide metal laminate was prepared and evaluated. did. The results are shown in Table 3A or Table 3B.

[Comparative Example 1]
Except not having used the imide oligomer, the polyimide resin composition was synthesize | combined and evaluated similarly to Example 1, and also the polyimide metal laminated body was produced and evaluated. The results are shown in Table 3A.

[Comparative Examples 2 and 3]
A polyimide resin composition was synthesized and evaluated in the same manner as in Example 1 except that the type of polyamic acid varnish and the crosslinkable group-containing additive bisimide was changed to those shown in Table 3B. Were made and evaluated. The results are shown in Table 3B.

As Table 3 showed, the metal laminated body manufactured using the resin composition (comparative example 1) which does not contain an imide oligomer shows that peel strength is inferior. Therefore, the performance as an adhesive may not be sufficient.
Moreover, the resin composition containing the bisimide instead of the imide oligomer (Comparative Examples 2 and 3) is inferior to the evaluation result of the volatility test, and part of the composition (considered as bisimide) when exposed to a high temperature environment. Can be sublimated.

  On the other hand, as shown in Examples 1 to 14, the resin composition containing any of the polyamic acid varnishes obtained in Synthesis Examples 1-1 to 1-14 and an imide oligomer has a high volatility test evaluation. The peel strength of the metal laminate produced using it is sufficient. In addition, as shown in Examples 15 and 16, the resin composition of the present invention shows excellent partiality irrespective of the polyamic acid solid content and the imide oligomer, but the polyamic acid solid content ratio is If it is too high (too little imide oligomer), the peel strength may be inferior, and if the amount ratio of the imide oligomer is too high, the evaluation of the volatility test may be lowered.

  In addition, as shown in Examples 17 to 29, the resin composition containing polyamic acid and any of the imide oligomers obtained in Synthesis Examples 2-2 to 2-14 has a high volatility test evaluation. The peel strength of the metal laminate produced using the is sufficient.

  The polyimide resin composition of the present invention can be used for heat-resistant films, flexible printed boards, semiconductor packages, and the like.

  This application claims the priority based on application number JP2006-244946 (Japanese Patent Application No. 2006-244946) of the application on September 11, 2006. All of the contents described in the application specification and the drawings are incorporated herein by reference.

Claims (10)

The polyimide resin containing the repeating unit represented by the following general formula (1-1) and the repeating unit represented by the general formula (1-2), and
A polyimide resin composition containing 20 to 100 parts by weight of an imide oligomer represented by the following general formula (2) with respect to 100 parts by weight of the polyimide resin.
[In the formulas (1-1) and (1-2),
One of A ₁ and A ₂ is the following formula (a1), the other is the following formula (a2), and the number ratio of (a1) and (a2) contained in the polyimide resin is 8: 2. ~ 5: 5 ,
B ₁ and B ₂ are respectively the following formulas (b1) or (b2), and may be the same or different from each other]
[In Formula (2),
A ₃ is any one of the following formulas (c1) ~ (c4),
B ₃ is any one of the following formulas (d1) ~ (d4),
Z is the following formula (e1) or (e2),
l is an integer of 1 to 5]
[In formulas (c1) to (c4), X _{7 to 12} are a direct _bond , —O—, —S—, —CO—, —COO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ). _{2 -, - SO 2 -,} - is selected from the group consisting of NHCO-, may be the same or different from each other]
[In formulas (d1) to (d4), _{Y7 to 12} are a direct _bond , —O—, —S—, —CO—, —COO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ). _{2 -, - SO 2 -,} - is selected from the group consisting of NHCO-, may be the same or different from each other]
[In the formula (e1) or (e2)
R _1-4 is selected from the group consisting of a hydrogen atom, a halogen atom, and an alkyl group having 1 to 3 carbon atoms, and may be the same or different from each other;
R ₅ is —O—, —S—, —CH ₂ —, —C (CH ₃ ) ₂ —, —CO—, or —COO—.   The polyimide resin composition according to claim 1, wherein l in the general formula (2) is 1. The polyimide resin composition according to claim 1 or 2 , wherein the glass transition temperature is in the range of 100 ° C or higher and 300 ° C or lower. In the general formula (2),
A ₃ is the following formula (c5) or (c6),
B ₃ is selected from the group consisting of the following formulas (d1) and (d5) to (d10):
Z is (e3) or (e4),
l is an integer of 1 to 5;
The polyimide resin composition according to any one of claims 1 to 3 .
[R ₃ and R ₄ are defined in the same manner as in the formula (e2)] A polyamic acid comprising a repeating unit represented by the following general formula (3-1) and a repeating unit represented by the following general formula (3-2);
A mixture containing 20 to 100 parts by weight of the imide oligomer represented by the general formula (2) with respect to 100 parts by weight of the polyimide resin , and a solvent as necessary.
[In the formulas (3-1) and (3-2)
One of A ₁ and A ₂ is the following formula (a1), the other is the following formula (a2), and the number ratio of (a1) and (a2) contained in the polyimide resin is 8: 2. ~ 5: 5 ,
B ₁ and B ₂ are respectively the following formulas (b1) or (b2), and may be the same or different from each other]
[In Formula (2),
A ₃ is any one of the following formulas (c1) ~ (c4),
B ₃ is any one of the following formulas (d1) ~ (d4),
Z is the following formula (e1) or (e2),
l is an integer of 1 to 5]
[In formulas (c1) to (c4), X _{7 to 12} are a direct _bond , —O—, —S—, —CO—, —COO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ). _{2 -, - SO 2 -,} - is selected from the group consisting of NHCO-, may be the same or different from each other]
[In formulas (d1) to (d4), _{Y7 to 12} are a direct _bond , —O—, —S—, —CO—, —COO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ). _{2 -, - SO 2 -,} - is selected from the group consisting of NHCO-, may be the same or different from each other]
[In the formula (e1) or (e2)
R _1-4 is selected from the group consisting of a hydrogen atom, a halogen atom, and an alkyl group having 1 to 3 carbon atoms, and may be the same or different from each other;
R ₅ is —O—, —S—, —CH ₂ —, —C (CH ₃ ) ₂ —, —CO—, or —COO—. The manufacturing method of a polyimide resin hardened | cured material including the step which heats the mixture of Claim 5 and carries out an imidation reaction. The film containing the hardened | cured material of the hardened | cured material of the polyimide-type resin composition as described in any one of Claims 1-4, or the mixture of Claim 5 . A metal laminate comprising a metal layer and a resin layer,
At least one layer of the resin layer is a metal laminate including a cured product of the polyimide resin composition according to any one of claims 1 to 4 or a cured product of the mixture according to claim 5 . A polyimide film, a polyimide layer formed on one or both sides of the polyimide film, a metal layer laminated on one or both of the polyimide layers,
Polyimide layer in contact with the metal layer is a resin layer made of a cured product of a mixture according to the cured product or claim 5 of a polyimide resin composition according to any one of claims 1-4, metal laminate body. Resin films, and laminated on one or both surfaces of the resin film, comprising a cured product of a mixture according to the cured product or claim 5 of a polyimide resin composition according to any one of claims 1-4 adhesive sheet having the resin layer.