JP2012236875A - Thermosetting resin composition and interlayer adhesive film for printed-wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermosetting resin composition that produces a cured product having excellent heat resistance and dimensional stability and a cured product of semi-curing (B-staged) having excellent melt processability and yet has a long pot life and an interlayer adhesive film obtained by using the resin composition.SOLUTION: The thermosetting resin composition comprises a polyimide resin (A) obtained by blocking a carboxy group of a straight-chain polyimide resin (a1) having a weight-average molecular weight of 5,000-60,000 and an acid value of carboxy group of 30-80 with a mono-epoxy compound (a2), an epoxy resin (B) and a curing agent (C) of the epoxy resin. The cured product of the composition is provided. The interlayer adhesive film for a printed-wiring board has a layer formed by the composition on a carrier film.

Description

  The present invention is obtained by using a cured product excellent in heat resistance and dimensional stability, a thermosetting resin composition capable of obtaining a semi-cured (B-staged) product excellent in melt processability, and the resin composition. The present invention relates to an interlayer adhesive film.

  In recent years, there has been an increasing demand for thinner, lighter and higher mounting density semiconductor components, and the wiring density of circuit boards is expected to increase further in the future. As means for improving the wiring density, for example, a three-dimensional circuit is formed by stacking wiring boards. In the future, the number of stacked layers is expected to reach more than 10 layers. The coating of inner layer circuit patterns, the melt processability to fill surface via holes and through holes, and the thermal expansion of insulating layers and circuit layers as the number of stacked layers increase. There is a demand for reduction in circuit strain stress due to the difference, and there has been a demand for a melt processability of the B-stage insulation of the insulating layer and a reduction in the thermal expansion coefficient of the C-stage insulation.

  As a resin composition for obtaining an insulating layer having a low coefficient of thermal expansion (excellent in dimensional stability), for example, a resin composition containing a polyimide resin having a biphenyl structure and an alicyclic structure is known (for example, Patent Document 1). Moreover, the resin composition containing the polyimide resin which has an alicyclic structure and has a phenolic hydroxyl group at the terminal is also known (for example, refer patent document 2).

  In particular, the resin composition disclosed in Patent Document 2 is disclosed as a resin composition having excellent stability, such as a long pot life, in addition to obtaining an insulating layer having low heat resistance and a low coefficient of thermal expansion. Yes. However, even in the resin composition described in Patent Document 2, the compatibility between the polyimide resin and the epoxy resin is not sufficient, and because the reactivity of the polyimide resin to the epoxy resin is high, a partial curing reaction occurs when the B stage is formed. Advances and melt processability is reduced.

International Publication No. 2010/0774014 Pamphlet International Publication No. 2010/098296 Pamphlet

  The present invention provides a cured product excellent in heat resistance and dimensional stability, a semi-cured (B-staged) cured product excellent in melt processability, and a thermosetting resin composition having a long pot life, An object of the present invention is to provide an interlayer adhesive film obtained by using a resin composition.

  As a result of intensive studies, the inventors of the present invention have a weight average molecular weight of 4,000 to 60,000 as a polyimide resin in a thermosetting resin composition containing a polyimide resin, an epoxy resin, and an epoxy resin curing agent. A polyimide resin excellent in compatibility with the epoxy resin by using a linear polyimide resin having a carboxyl group acid value of 30 to 80 and further sealing the carboxyl group of the polyimide resin with a monoepoxy compound It is found that by using a polyimide resin sealed with a monoepoxy compound, a resin composition having excellent melt processability of the B-stage film and a low coefficient of thermal expansion after C-stage curing can be obtained. It came to complete.

  That is, the present invention seals the carboxyl group of the linear polyimide resin (a1) having a weight average molecular weight of 4,000 to 60,000 and an acid value of the carboxyl group of 30 to 80 with the monoepoxy compound (a2). A thermosetting resin composition comprising a stopped polyimide resin (A), an epoxy resin (B), and a curing agent (C) for an epoxy resin is provided.

  Moreover, this invention provides the interlayer adhesive film for printed wiring boards characterized by being obtained by apply | coating and drying the said thermosetting resin composition on a carrier film.

  The thermosetting resin composition of the present invention is excellent in the melt processability of the cured product in the B-stage, the cured product has a low coefficient of linear expansion, and is excellent in dimensional stability. In addition, the pot life is long, and a cured product of the same quality can be obtained even in a long-time operation using the composition. It can be used in various fields by utilizing these performances. Specifically, engine peripheral parts, sliding parts, HDD sliding parts, voice coils, electromagnetic coils, coating agents for various films, insulation coatings for electric wires, heat resistance such as cooking devices, insulation Applications requiring coating properties: Fiber reinforced composite materials such as carbon and glass fiber prepregs, printed wiring boards, semiconductor insulation materials, coverlays, surface protection layers such as solder resists, build-up materials, prepreg resins, Insulating materials for flexible displays, organic TFT insulating layers, buffer coatings, semiconductor coatings such as Low-k, polymer waveguides, semiconductor encapsulants, adhesives such as underfill, etc. Applications: solar cells, lithium batteries, capacitors Insulating layers such as electric double layer capacitors, electrode binders, various energy industrial materials such as separators, etc. It can be used for endless belts such as laser printers, copier transfer belts, fixing belts or coating agents, conductive films, heat dissipation film binders, color filter alignment films, overcoat films, etc. Especially for insulation of multilayer printed wiring boards, etc. It can be suitably used for layers and solder resists. Also, by using the interlayer adhesive film for printed wiring boards of the present invention, an insulating layer having a low coefficient of linear expansion of the cured product can be obtained while being melted at a low temperature at the time of crimping with a copper foil. It is suitably used as an adhesive film for forming an insulating layer.

  The polyimide resin (A) used in the present invention is a monoepoxy compound (a2) having a carboxyl group of a linear polyimide resin (a1) having a weight average molecular weight of 4,000 to 60,000 and an acid value of 30 to 80. It is sealed. If the weight average molecular weight of the linear polyimide resin (a1) is less than 3,000, the melt processability is good but the coefficient of thermal expansion of the cured product is high, which is not preferable. Moreover, when the weight average molecular weight is larger than 60,000, the melt processability of the B-staged cured product is inferior. The weight average molecular weight of the linear polyimide resin (a1) is more preferably 4,000 to 30,000.

  Moreover, the polyimide resin (a1) used by this invention needs to be the acid value of a carboxyl group 30-90 KOHmg / g. If the acid value of the carboxyl group is less than 30 KOHmg / g, the melting characteristics are inferior, which is not preferable. When the acid value of the carboxyl group is larger than 90 KOH mg / g, the cured film tends to thermally expand, which is not preferable. The acid value of the carboxyl group is preferably 30 to 80, and the acid value of the carboxyl group is more preferably 50 to 80.

In the present invention, the weight average molecular weight was measured using a gel permeation chromatograph (GPC) under the following conditions.
Measuring device: Tosoh Corporation HLC-8320GPC, UV8320
Column: Super AWM-H × 2 manufactured by Tosoh Corporation Detector: RI (differential refractometer) and UV (254 nm)
Data processing: Tosoh Corporation EcoSEC-WorkStation
Measurement conditions: Column temperature 40 ° C
Solvent DMF
Flow rate 0.35 ml / min Standard: Calibration curve prepared with polystyrene standard sample Sample: 0.2% by weight DMF solution in terms of resin solid content filtered through a microfilter (injection volume: 10 μl)

  As for linear polyimide resin (a1), the method of making bifunctional isocyanate and an acid anhydride react is mentioned, for example. It is also possible to obtain a similar imide resin by reacting an amine compound with an acid anhydride instead of an isocyanate compound.

  Among the linear polyimide resins (a1), a polyimide resin having a biphenyl skeleton directly connected to a five-membered ring imide skeleton is preferable because a cured product having excellent dimensional stability is obtained. Among them, the content of the biphenyl skeleton is preferably 20 to 45% by mass because a thermosetting resin composition having both dimensional stability and low-temperature meltability is obtained, and more preferably 25 to 35% by mass.

  The logarithmic viscosity of the linear polyimide resin (a1) is preferably 0.2 to 0.8 dl / g because a cured product having sufficient strength can be obtained, and more preferably 0.3 to 0.7 dl / g.

  Accordingly, the linear polyimide resin (a1) has a biphenyl skeleton directly linked to a 5-membered ring imide skeleton, the content of the biphenyl skeleton is 20 to 45% by mass, and the logarithmic viscosity is 0.2 to 0. .8 dl / g of polyimide resin is preferable, has a biphenyl skeleton directly linked to a five-membered ring imide skeleton, the content of the biphenyl skeleton is 25 to 35% by mass, and the logarithmic viscosity is 0.3 to 0.7 dl. / G of polyimide resin is more preferable.

  The content of the biphenyl structure is based on the weight of the entire polyimide resin, assuming that the molecular weight is 152 in the case of a biphenyl structure with two bonding sites to the polyimide resin main chain and the molecular weight is 150 in the case of a biphenyl structure with four bonding sites. It can be calculated from the ratio of the occupying biphenyl structure.

In the present invention, the logarithmic viscosity of the polyimide resin was determined under the following conditions.
A polyimide resin was dissolved in N-methyl-2-pyrrolidone so that the resin concentration was 0.5 g / dl to obtain a resin solution. The solution viscosity of the resin solution and the solvent viscosity (viscosity of N-methyl-2-pyrrolidone) were measured at 30 ° C. with an Ubbelohde type viscosity tube, and the obtained measured values were obtained by applying the following formulas. .

Logarithmic viscosity (dl / g) = [ln (V1 / V2)] / V3
In the above formula, V1 represents the solution viscosity measured with an Ubbelohde type viscosity tube, and V2 represents the solvent viscosity measured with an Ubbelohde type viscosity tube. Here, V1 and V2 were determined from the time required for the resin solution and the solvent (N-methyl-2-pyrrolidone) to pass through the capillary of the viscosity tube. V3 is the polymer concentration (g / dl).

  The polyimide resin having a biphenyl skeleton directly connected to the 5-membered ring imide skeleton is, for example, other than a polyisocyanate compound having a biphenyl structure and / or an acid anhydride having a biphenyl structure and, if necessary, a polyisocyanate compound having a biphenyl structure. It can be easily obtained by reacting an acid anhydride other than the polyisocyanate compound or an acid anhydride having a biphenyl structure.

  Examples of the polyisocyanate compound having a biphenyl structure include 4,4′-diisocyanate-3,3′-dimethyl-1,1′-biphenyl, 4,4′-diisocyanate-3,3′-diethyl-1, 1'-biphenyl, 4,4'-diisocyanate-2,2'-dimethyl-1,1'-biphenyl, 4,4'-diisocyanate-2,2'-diethyl-1,1'-biphenyl, 4,4 Examples include '-diisocyanate-3,3'-ditrifluoromethyl-1,1'-biphenyl, 4,4'-diisocyanate-2,2'-ditrifluoromethyl-1,1'-biphenyl, and the like.

  Examples of the acid anhydride having a biphenyl structure include biphenyl-3,3 ′, 4,4′-tetracarboxylic acid, biphenyl-2,3,3 ′, 4′-tetracarboxylic acid, and monoanhydrides thereof. Products, dianhydrides and the like, and these can be used alone or as a mixture of two or more.

  Examples of the polyisocyanate compound other than the polyisocyanate compound having a biphenyl structure include aromatic polyisocyanates and aliphatic polyisocyanates other than the polyisocyanate compound having a biphenyl structure.

  Examples of the aromatic polyisocyanate other than the polyisocyanate compound having a biphenyl structure include p-phenylene diisocyanate, m-phenylene diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 2,4-tolylene diisocyanate, and 2,6. -Tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, 3,3'-diethyldiphenyl-4,4'-diisocyanate, m-xylene diisocyanate, p- Xylene diisocyanate, 1,3-bis (α, α-dimethylisocyanatomethyl) benzene, tetramethylxylylene diisocyanate, diphenylene ether-4,4'-diisocyanate and na Data diisocyanate, and the like.

  Examples of the aliphatic polyisocyanate compound include hexamethylene diisocyanate, lysine diisocyanate, trimethylhexamethylenemethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, hydrogenated xylene diisocyanate, and norbornene diisocyanate.

  As the polyisocyanate compound, it is also possible to use an isocyanate prepolymer obtained by reacting the polyisocyanate compound and various polyol components in advance with an excess of isocyanate groups.

  Examples of acid anhydrides other than acid anhydrides having a biphenyl structure include aromatic tricarboxylic acid anhydrides other than acid anhydrides having a biphenyl structure, alicyclic tricarboxylic acid anhydrides, and acid anhydrides having a biphenyl structure. Examples include tetracarboxylic acid anhydride. Examples of aromatic tricarboxylic acid anhydrides other than acid anhydrides having a biphenyl structure include trimellitic anhydride and naphthalene-1,2,4-tricarboxylic acid anhydride.

  Examples of the alicyclic tricarboxylic acid anhydride include cyclohexane-1,3,4-tricarboxylic acid anhydride-3,4-anhydride, cyclohexane-1,3,5-tricarboxylic acid anhydride-3,5-anhydride, And cyclohexane-1,2,3-tricarboxylic acid anhydride-2,3-anhydride.

  Examples of the tetracarboxylic acid anhydride other than the acid anhydride having a biphenyl structure include pyromellitic dianhydride, benzophenone-3,3 ', 4,4'-tetracarboxylic dianhydride, diphenyl ether-3, 3 ', 4,4'-tetracarboxylic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride, naphthalene -1,2,4,5-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, decahydronaphthalene-1,4,5,8-tetracarboxylic dianhydride 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4 5,8-teto Carboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic Acid dianhydride, phenanthrene-1,3,9,10-tetracarboxylic dianhydride, berylene-3,4,9,10-tetracarboxylic 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-dicarboxy) Phenyl) ethane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,3-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4 -Dicarboxyfe Le) sulfone dianhydride, bis (3,4-carboxyphenyl) ether dianhydride,

Ethylene glycol bisanhydro trimellitate, propylene glycol bis anhydro trimellitate, butanediol bis anhydro trimellitate, hexamethylene glycol bis anhydro trimellitate, polyethylene glycol bis anhydro trimellitate, polypropylene lenglycol bis Anhydro trimellitate, other alkylene glycol bisan hydroxy trimellitate, etc. are mentioned.

  The polyimide (a1) used in the present invention is preferable because a polyimide resin having a benzophenone structure further exhibits heat resistance and low linear expansion. A polyimide resin having a benzophenone structure can be obtained, for example, by using benzophenone tetracarboxylic acid anhydride as an essential component in the production method.

  The content of the benzophenone structure is preferably from 1 to 30% by mass based on the mass of the polyimide resin, since a cured product having excellent heat resistance is obtained, and more preferably from 5 to 20% by mass is excellent in synthetic stability.

  The content of the benzophenone structure can be calculated from the ratio of the benzophenone structure to the total weight of the polyimide resin, with the molecular weight of the benzophenone structure having 4 bonding points to the polyimide resin main chain being 178.

  In addition, the polyimide (a1) used in the present invention is preferably a polyimide resin having a tolylene structure bonded to the main chain at the 2nd and 4th positions because it easily develops melt adhesion and low linear expansion. A polyimide resin having a tolylene structure bonded to the main chain at positions 2 and 4 can be obtained, for example, by using toluene diisocyanate as an essential component in the production method.

  The content of the tolylene structure bonded to the main chain at the 2nd and 4th positions is based on the ratio of the tolylene structure to the total weight of the polyimide resin, assuming that the molecular weight of the tolylene structure bonded at the 2nd and 4th positions to the polyimide resin main chain is 150. Can be calculated.

  The content of the tolylene structure bonded to the main chain at positions 2 and 4 in the polyimide resin is preferably 1 to 20% by mass because it is excellent in synthetic stability, and 2 to 14% by weight is low in linear expansion and synthetic stability. More preferable.

  Moreover, among the polyimide resins (a1) used in the present invention, polyimide resins having an alicyclic structure together with the biphenyl skeleton can also be used. By selecting such a polyimide resin, it is expected that a thermosetting resin composition having good solubility in a solvent and excellent storage stability will be obtained. Especially, the polyimide resin which has a structure represented by the following general formula (1a) or general formula (1i) can be illustrated.

（式中Ｒ_１はそれぞれ独立して水素原子、炭素原子数１〜９の炭化水素基を示す。）

(In the formula, each R ₁ independently represents a hydrogen atom or a hydrocarbon group having 1 to 9 carbon atoms.)

The substitution position of R ₁ is located at the 3,3′-position on the biphenyl skeleton, and the following general formulas (1a ′) and (1i ′)

（式中Ｒ_１はそれぞれ独立して水素原子、炭素原子数１〜９の炭化水素基を示す。）で表される構造を有するものが溶剤溶解性をより向上させることができる。溶剤溶解性がさらに向上する結果、ポリイミド樹脂の各種物性、例えば、ポリイミド樹脂の保存安定性や、ビフェニル骨格を導入したことによる硬化物の耐熱性、寸法安定性及び機械物性（強靱性、柔軟性）をより向上させるだけでなく、さらにメラミン樹脂等の他の樹脂との相溶性も向上させ、銅箔との密着性をより向上させることが期待される。前記Ｒ_１は水酸基の一部乃至全部がハロゲン等で置換されていても良い。Ｒ_１としては炭素原子数１〜５の炭化水素基が好ましく、Ｒ_１としては炭素原子数１〜３の炭化水素基が好ましく、炭素原子数が１の炭化水素基（メチル基）が更に好ましい。なお、一般式（１ａ）、（１ｉ）以外の式中のＲ_１についても同様である。

(In the formula, each R ₁ independently represents a hydrogen atom or a hydrocarbon group having 1 to 9 carbon atoms.) The solvent solubility can be further improved. As a result of further improvement in solvent solubility, various physical properties of polyimide resin, such as storage stability of polyimide resin, heat resistance of cured product by introducing biphenyl skeleton, dimensional stability and mechanical properties (toughness, flexibility) ) Is further improved, and the compatibility with other resins such as melamine resin is further improved, and the adhesion with the copper foil is expected to be further improved. In R ₁ , some or all of the hydroxyl groups may be substituted with halogen or the like. R ₁ is preferably a hydrocarbon group having 1 to 5 carbon atoms, R ₁ is preferably a hydrocarbon group having 1 to 3 carbon atoms, and more preferably a hydrocarbon group having 1 carbon atom (methyl group). . The same applies to R _{1 in} the formulas other than the general formulas (1a) and (1i).

  Examples of the structure represented by the general formulas (1a) and (1i) include the following structures.

  As the polyimide resin (a1) used in the present invention, it can be expected that a cured product having excellent solvent solubility and excellent mechanical properties and dimensional stability can be obtained by the formulas (1a-1) and (1i-1). A polyimide resin having the structure represented is preferred.

  Among the polyimide resins of the present invention, the polyimide resin having the structure represented by the general formulas (1a) and (1i) is, for example, a polyimide resin having a structure represented by the following general formula (I) as a repeating unit (hereinafter, polyimide resin). (Sometimes referred to as (1))).

However, Table in the general formula (I), * represents a point of attachment that can form an amide bond or an imide bond, m is in the range of 1 to 1000, _{A 1} in the above general formula (1a) and (1i) Is the structure.
The structural unit represented by the general formula (I) may be arranged randomly, in blocks, alternately, etc. in one molecule.

  The content of the structural unit represented by the general formula (I) in the polyimide resin of the present invention is 1 to 90% by weight based on the weight of the polyimide resin used in the present invention, and becomes a polyimide resin excellent in solvent solubility, and From the viewpoint of obtaining a cured product having excellent heat resistance, mechanical properties and dimensional stability, it is preferably 2 to 70% by weight, more preferably 2 to 50% by weight.

  In addition to the general formulas (1a) and (1i), the polyimide resin of the present invention is a cured product in which a polyimide resin having a structure represented by the following general formulas (2a) and (2i) is excellent in heat resistance. Is preferable because it is a polyimide resin obtained.

（式中Ｒ_１はそれぞれ独立して水素原子、炭素原子数１〜９の炭化水素基を示す。）
前記一般式（２）において、一般式（１ａ’）および（１ｉ’）と同様の理由から、下記一般式（２ａ’）及び（２ｉ’）

(In the formula, each R ₁ independently represents a hydrogen atom or a hydrocarbon group having 1 to 9 carbon atoms.)
In the general formula (2), for the same reason as in the general formulas (1a ′) and (1i ′), the following general formulas (2a ′) and (2i ′)

（式中Ｒ_１はそれぞれ独立して水素原子、炭素原子数１〜９の炭化水素基を示す。）で表される構造を有するポリイミド樹脂が好ましい。
前記一般式（２ａ）および（２ｉ）中のＲ_１は水酸基の一部乃至全部がハロゲン等で置換されていても良い。

A polyimide resin having a structure represented by (in the formula, each R ₁ independently represents a hydrogen atom or a hydrocarbon group having 1 to 9 carbon atoms) is preferable.
In R ₁ in the general formulas (2a) and (2i), part or all of the hydroxyl groups may be substituted with halogen or the like.

  Examples of the structure represented by the general formulas (2a) and (2i) include the following structures.

When the polyimide resin of the present invention has a structure represented by the general formulas (2a) and (2i), R ₁ of the structure represented by the general formulas (2a) and (2i) is represented by the general formula (1a) and It may be the same as or different from R _{1 of the} structure represented by (1i).

  Among the structures represented by the general formulas (2a) and (2i), the general formulas (2a-1) and (2i-1) are obtained because a coating film having excellent solvent solubility and excellent mechanical properties and dimensional stability is obtained. ) Is preferred.

  Moreover, when the polyimide resin used by this invention is a polyimide resin which has the structure of the said General formula (2a) and (2i), content of the structure shown to General formula (2a) and (2i) in this polyimide resin The total is 1 to 70% by weight based on the weight of the polyimide resin, which is a polyimide resin excellent in solvent solubility, and excellent in mechanical properties such as heat resistance, tensile strength and elongation, and dimensional stability, at a high temperature. This is preferable because a cured product having excellent thermal decomposability is obtained, and more preferably 2 to 60% by weight.

  Among the polyimide resins used in the present invention, a polyimide resin having a structure represented by the general formulas (1a) and (1i) and a structure represented by the general formulas (2a) and (2i) is, for example, the following general formula: Examples thereof include polyimide resins having the structures of (I) and (II) as repeating units (hereinafter sometimes referred to as polyimide resin (2)).

However, in the general formula (I) and (II), * indicates the point of attachment capable of forming an amide bond or an imide bond, m, n is in the range of respectively 1 to 1000, _{A 1} is the general formula (1a ) And (1i), and A ₂ is a structure represented by the general formulas (2a) and (2i).

  The structural units represented by the general formulas (I) and (II) may be arranged randomly, in blocks, alternately, etc. in each molecule.

  In the polyimide resin (2), the total content of the structural units represented by the general formulas (I) and (II) is such that a cured product having excellent solvent solubility and dimensional stability can be obtained. 10) to 90% by weight is preferable, and 20 to 80% by weight is more preferable. Moreover, as a weight ratio of each structural unit represented by the general formulas (I) and (II), a cured product having excellent solvent solubility and excellent heat resistance, mechanical properties and dimensional stability can be obtained ( A range of I) :( II) = 1: 20 to 20: 1 is preferred.

  As the polyimide resin used in the present invention, in addition to the structure represented by the above (1a) or (1I), the polyimide resin having a structure represented by the following general formula (3) is flexible while maintaining heat resistance. Is also preferable because an excellent cured product is obtained.

  When the polyimide resin of the present invention is a polyimide resin having the structure of the general formula (3), the content of the structure of the general formula (3) in the polyimide resin is 5 to 30% by weight in solvent solubility. The amount is preferably 5 to 20% by weight because a cured product having an excellent polyimide resin and a high breaking strength can be obtained.

  Examples of the polyimide resin having the structure represented by the general formula (3) include a polyimide resin having the following structure.

  As a polyimide resin having a structure represented by the general formula (3), for example, a polyimide resin having the following structures (I) to (IV) as a repeating unit (hereinafter sometimes referred to as polyimide resin (3)). Etc.

However, in the general formula (I) ~ (IV), * indicates the point of attachment capable of forming an amide bond or an imide bond, m, n, p, q is in the range of respectively 1 to 1000, _{A 1} is the A ₂ is a structure represented by the general formulas (1a) and (1i), A ₂ is a structure represented by the above general formulas (2a) and (2i), and A ₃ is a structure represented by the above general formula (3a-1) and (3i-1) is a structure represented by, _{a 4} is a structure represented by the general formula (3a-2) and (3i-2). The structural units represented by the general formulas (I) to (IV) may be arranged randomly, in blocks, alternately, etc. in each molecule.

The arrangement of the structural units may or may not have specific regularity and regularity. Therefore, the structural unit (A _{1 to} A ₄ ) having an imide bond of each copolymer may appear multiple times in the polyimide resin.

  Since the total amount in the molecule of the structure represented by the general formulas (I) to (IV) is a polyimide resin excellent in solvent solubility, and a coating film excellent in dimensional stability and mechanical properties is obtained. 1-1000 are respectively preferable and 1-500 are more preferable.

  In the polyimide resin (3), the content of each structural unit represented by the general formulas (I) to (IV) is a cured product having excellent solvent solubility and excellent heat resistance, mechanical properties, and dimensional stability. Since it is obtained, it is preferably 1% by weight or more, more preferably 1 to 80% by weight, respectively, based on the weight of the polyimide resin.

  In the polyimide resin (3), the ratio between the structural units represented by the general formulas (I) to (IV) is (I), (II), where the total amount of the general formulas (I) to (IV) is 1. ), (III), and (IV) in the order of 0.02 to 0.9, 0.02 to 0.9, 0.02 to 0.8, and 0.02 to 0.8, respectively, solvent solubility It is preferable because it becomes a polyimide resin excellent in mechanical properties, heat resistance, and dimensional stability, and further 0.1 to 0.8, 0.1 to 0.8, 0.05 to 0.7, 0.05 to A polyimide resin that is 0.7 is more preferable, and polyimide resins that are 0.1 to 0.6, 0.2 to 0.7, 0.1 to 0.5, and 0.1 to 0.5, respectively, are most preferable. preferable.

In the general formulas (I) and (II), it is more preferable that A ₁ is (1a-1) and (1i-1) and A ₂ is (2a-1) and (2i-1).

  Moreover, as a polyimide resin (a1) used by this invention, in addition to the structure represented by the said General formula (1a) and (1i), the polyimide resin which has a structure represented by following General formula (4) further, It is preferable because a cured product having excellent heat resistance can be obtained.

  When the polyimide resin used in the present invention is a polyimide resin having the structure of the general formula (4), the content of the structure of the general formula (4) in the polyimide resin is 1 to 30% by weight, which is a good preservation. It is preferable that a cured product having excellent heat resistance is obtained while maintaining stability, and more preferably 1 to 20% by weight.

  Examples of the polyimide resin having the structure represented by the general formula (4) include a polyimide resin having the following structure.

  Examples of the polyimide resin having the structure represented by the formula (4) include a polyimide resin having a structure represented by the following general formulas (I) to (VI) below as a repeating unit (hereinafter referred to as polyimide resin (4)). And the like.

However, in the general formulas (I) to (VI), * represents a bonding point capable of forming an amide bond or an imide bond, and m, n, p, q, r, and s are each in the range of 1 to 1000; A ₁ is a structure represented by the above general formulas (1a) and (1i), A ₂ is a structure represented by the above general formulas (2a) and (2i), and A ₃ is a structure represented by the above general formula (3a -1) and (3i-1) is a structure represented by, _{a 4} is a structure represented by the general formula (3a-2) and (3i-2), _{a 5} is the general formula (4 a structure represented by -1), _{a 6} is a structure represented by the general formula (4-2).
The structural units represented by the general formulas (I) to (VI) may be arranged randomly, in blocks, alternately, etc. in each molecule. These structural units may exist several times in one molecule, and may contain other structural units.

The proportion of each structural unit represented by the general formulas (I) to (VI) in the polyimide resin (4) is 1% by weight or more as a proportion suitable for solving the problems of the present invention. More preferably, it is 1 to 70% by weight. Furthermore, in order to improve dimensional stability, the total amount of the structures represented by the general formulas (I) and (II) is preferably 20 to 80% by weight with respect to the polyimide resin. The total amount of the structural units represented by I) and (III) is preferably 10 to 80% by weight based on the polyimide resin. Further, the total amount of the structural units represented by the general formulas (III) and (IV) is preferably 10 to 70% by weight in order to break the crystallinity of the structures (A ₁ ) and (A ₂ ). The total amount of the structural units represented by the general formulas (V) and (VI) is preferably 5 to 30% by weight from the viewpoint of improving the dissolution stability with time and improving the breaking strength.

  Moreover, the following structure can be introduce | transduced into the said polyimide resin (1)-(4), and the flame retardance of the hardened | cured material of a polyimide resin can also be improved.

In the formula, R ₂ is the same as R ₁ and independently represents a hydrogen atom or a hydrocarbon group having 1 to 9 carbon atoms.
Examples of the polyimide resin having the structure represented by the general formulas (5a-1) to (5-3) include a polyimide resin having the following structures (I) to (IX) as repeating units (hereinafter referred to as polyimide resin ( 5))) and the like.

However, in the general formula (I) ~ (IX), * indicates the point of attachment capable of forming an amide bond or an imide bond, M～v ranges of respectively 1 to 1000, _{A 1} is the general formula (1a ) And (1i), A ₂ is a structure represented by the above general formulas (2a) and (2i), and A ₃ is a structure represented by the above general formulas (3a-1) and (3i-1). ), A ₄ is a structure represented by the above general formulas (3a-2) and (3i-2), and A ₅ is a structure represented by the above general formula (4-1). A ₆ is a structure represented by the above general formula (4-2), A ₇ is a structure represented by the above general formulas (5a-1) and (5i-1), and A ₈ is a structure represented by the general formula (5a-2) and (5i-2), _{a 9} is represented by the general formula (5-3) It is a structure.

  The structural units represented by the general formulas (I) to (IX) may be arranged randomly, in blocks, alternately, etc. in each molecule.

  Moreover, when the structural unit represented by general formula (VII)-(IX) is contained in a polyimide resin, there is no structural unit represented by general formula (III), (IV), (VI). Can be good too. For example, a polyamide resin (6) having a structure represented by the following general formula (I), general formula (II), general formula (VII) and general formula (VIII) as a repeating unit

や下記一般式（Ｉ）、一般式（ＩＩ）、一般式（ＶＩＩ）、一般式（ＶＩＩＩ）および一般式（ＩＸ）で表される構造を繰り返し単位として有するポリアミド樹脂（６’）が特に優れた低線膨張係数を有する硬化物が得られることから好ましい。

And the polyamide resin (6 ′) having a structure represented by the following general formula (I), general formula (II), general formula (VII), general formula (VIII) and general formula (IX) as a repeating unit is particularly excellent. Further, a cured product having a low linear expansion coefficient is preferable.

However, in General Formula (I), General Formula (II), General Formula (VII), General Formula (VIII), and General Formula (IX), * represents a bonding point that can form an amide bond or an imide bond, m , N, t, u, v are each in the range of 1-1000, A ₁ is a structure represented by the above general formulas (1a) and (1i), and A ₂ is the above general formula (2a) and ( a structure represented by 2i), _{a 7} is a structure represented by the general formula (5a-1) and (5i-1), _{a 8} is the general formula (5a-2) and (5I- a structure represented by 2), _{a 9} is a structure represented by the general formula (5-3).
The structural units represented by the general formula (I), the general formula (II), the general formula (VII), the general formula (VIII), and the general formula (IX) are arranged randomly, in blocks, alternately, etc. in one molecule, respectively. Be good.

  The polyimide resin represented by the above (1a) or (1i) has a property of being easily dissolved in an organic solvent as well as being a resin having excellent storage stability. The polyimide resin of the present invention dissolves in conventionally used polar solvent organic solvents such as N-methylpyrrolidone and dimethylformamide, but it is relatively difficult to use gamma-butyrolactone (γ-butyrolactone) which has not been used conventionally. It can be dissolved in an organic solvent having a weak dissolving power.

  Whether or not the polyimide resin represented by the above (1a) or (1i) is dissolved in an organic solvent is determined by adding the polyimide resin concentration of the present invention to 10% by weight in an organic solvent and adding 7% at 25 ° C. This was performed by observing the appearance visually after standing for days. Among the polyimide resins of the present invention, a polyimide resin that is soluble in gamma-butyrolactone at 25 ° C. at a concentration of 10% by weight is preferable.

  The polyimide resin (a1) used in the present invention is preferably a polyimide resin that dissolves in gamma-butyrolactone is a polyimide resin that has excellent storage stability, and a polyimide resin that dissolves in gamma-butyrolactone at 25 ° C. so as to be 10% by weight. preferable. In order to obtain a polyimide resin that dissolves in gamma butyrolactone, it can be obtained, for example, by a method for producing a polyimide resin described later.

The polyimide resin represented by (1a) or (1i) can be produced, for example, by the following method.
Production Method 1: A method of directly imidizing using a polyisocyanate compound containing a diisocyanate compound having a biphenyl structure and an acid anhydride compound containing cyclohexanetricarboxylic acid anhydride (isocyanate method).
Production method 2: A method in which cyclohexanetricarboxylic acid anhydride and a diamine compound containing a diamine compound having a biphenyl structure are reacted to synthesize an amic acid, and then a dehydration reaction of the amic acid is performed to imide ring closure.

  In order to produce the polyimide resin of the present invention, the amount of remaining water can be reduced and the physical properties can be kept good, the reaction can be easily controlled, and the polyimide resin subjected to various modifications can be easily prepared. The isocyanate method (a method for producing a polyimide resin in which a diisocyanate compound having a biphenyl structure and a cyclohexanetricarboxylic acid anhydride are reacted with an acid anhydride compound) is preferred.

  Examples of the diisocyanate having the biphenyl structure include the diisocyanates described above. Among them, diisocyanate which is 4,4′-diisocyanate-3,3′-dialkyl-1,1′-biphenyl represented by the following formula, and 4,4′-diisocyanate-3,3′-dimethyl-1,1′- The diisocyanate which is biphenyl is preferable because a cured product having excellent solvent solubility and excellent heat resistance, mechanical properties and dimensional stability can be obtained.

  The diisocyanate compound represented by the general formula (7) can obtain a particularly low linear expansion coefficient (dimensional stability) as a polyimide resin having the effects of the present invention by using 10% by weight or more of the total isocyanate compound. It is preferable to use 10 to 80% by weight of the total isocyanate compound from the viewpoint of solution stability over time.

  As the polyisocyanate compound to be used in combination, aromatic diisocyanate can be used because of improved solvent properties and solution stability over time and mechanical properties such as mechanical strength and elongation at break of the resulting cured product and heat resistance. Among the aromatic diisocyanates, 4,4′-diphenylmethane diisocyanate and / or toluene diisocyanate are more preferable.

  The polyisocyanate compound used in combination may be used alone or in combination of two or more. By using 2 or more types together, it can be expected to easily obtain a polyimide resin having improved solubility and compatibility with various resins. Also when used together, when 4,4'-diphenylmethane diisocyanate and / or toluene diisocyanate is used in an amount of 10% by weight or more based on the weight of the polyisocyanate compound, a cured product having excellent mechanical properties such as mechanical strength and elongation at break and heat resistance. Is preferable. Further, use of toluene diisocyanate is preferable because flame retardancy is improved.

  The amount of the 4,4′-diphenylmethane diisocyanate and / or toluene diisocyanate used as the polyisocyanate compound is preferably 10 to 70 mol% based on the molar amount of all diisocyanate raw materials constituting the polyimide resin, and preferably 10 to 60 mol. % Is more preferable, and 20 to 60 mol% is still more preferable.

  Examples of the cyclohexanetricarboxylic acid anhydride include, for example, cyclohexane-1,3,4-tricarboxylic acid anhydride-3,4-anhydride, cyclohexane-1,3,5-tricarboxylic acid anhydride-3,5-anhydride. , Cyclohexane-1,2,3-tricarboxylic acid anhydride-2,3-anhydride and the like. Among them, cyclohexane-1,3,4-tricarboxylic acid anhydride represented by the formula (8) is obtained because a cured product having excellent solvent solubility and mechanical properties such as mechanical strength and elongation at break and heat resistance is obtained. -3,4-anhydride is preferred.

  The cyclohexanetricarboxylic acid anhydride is used in a range in which impurities such as cyclohexane-1,2,4-tricarboxylic acid used as a production raw material do not impair the curing of the present invention, for example, 10% by weight or less, preferably 5% by weight. The following may be mixed.

  When the cyclohexanetricarboxylic acid anhydride reacts with an isocyanate compound, the acid anhydride group and the isocyanate group decarboxylate to form an imide bond, and the isocyanate group and carboxylic acid decarboxylate to form an amide bond. In this way, molecules are connected linearly to form molecules.

  In the said manufacturing method, polycarboxylic acid anhydrides other than the said cyclohexane tricarboxylic acid anhydride can be used together in the range which does not impair the effect of this invention.

  In addition, the above-mentioned cyclohexanetricarboxylic acid anhydride and trimellitic anhydride are used in combination in terms of the balance between solvent solubility, mechanical properties, and heat resistance, and cyclohexanetricarboxylic acid anhydride and benzophenone-3,3 ', 4,4'- More preferred is a combined use of tetracarboxylic dianhydride, a combined use of cyclohexanetricarboxylic anhydride and pyromellitic dianhydride, and more preferred is cyclohexanetricarboxylic anhydride, trimellitic anhydride, benzophenone-3,3 ', More preferred is a combination of two or more selected from the group consisting of 4,4'-tetracarboxylic dianhydride and pyromellitic dianhydride, and cyclohexanetricarboxylic anhydride, trimellitic anhydride, benzophenone-3,3. Three types of combination of ', 4,4'-tetracarboxylic dianhydride are more preferable.

  In addition, aromatic, aliphatic, and alicyclic dicarboxylic acid compounds, polycarboxylic acid compounds, monoalcohol compounds, diol compounds, and trifunctional or higher functional polyol compounds can be used in combination as long as the effects of the present invention are not impaired. is there. Examples of the aromatic, aliphatic, and alicyclic dicarboxylic acid compounds and polycarboxylic acid compounds include phthalic acid, fumaric acid, adipic acid, sebacic acid, succinic acid, maleic acid, cyclohesisandicarboxylic acid, trimellitic acid, Examples include pyromellitic acid, monoalcohol compounds, diol compounds, trifunctional or higher polyol compounds such as methanol, ethanol, propanol, ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 3 methyl 1,5-pentanediol, Examples include hexanediol, nonanediol, trimethylolpropane, pentaerythritol, polyether polyol, polyester polyol, polycarbonate polyol, and polydimethylsiloxane polyol.

  The amount of the cyclohexanetricarboxylic acid anhydride used is 5-100 mol% in the total acid anhydride compound constituting the polyimide resin becomes a polyimide resin excellent in solvent solubility, and a cured product excellent in mechanical properties and heat resistance. Is preferable, and 10 to 80 mol% is more preferable. The amount of the cyclohexanetricarboxylic acid anhydride used is preferably 2 to 60 mol%, more preferably 2 to 50 mol% based on the molar amount of all raw materials constituting the polyimide resin.

  The amount used when trimellitic anhydride is used in combination with cyclohexanetricarboxylic acid anhydride as the acid anhydride is similarly 5 to 90 mol% cyclohexanetricarboxylic acid anhydride based on the molar amount of the total acid anhydride compound, trimellitic anhydride. The acid is preferably 10 to 95 mol%, more preferably cyclohexanetricarboxylic acid anhydride 5 to 60 mol%, and trimellitic anhydride 40 to 95 mol%. Moreover, the usage-amounts of the said cyclohexanetricarboxylic acid anhydride and trimellitic anhydride are 2-60 mol% and 2-60 mol% respectively on the basis of the molar amount of all the raw materials which comprise a polyimide resin.

  When trimellitic anhydride and benzophenone-3,3 ', 4,4'-tetracarboxylic dianhydride are used in combination with cyclohexanetricarboxylic acid anhydride as the acid anhydride, the moles of all acid anhydrides constituting the imide resin Preferred is 5 to 95 mol% cyclohexanetricarboxylic anhydride, 2 to 92 mol% trimellitic anhydride, 3 to 50 mol% benzophenone-3,3 ', 4,4'-tetracarboxylic dianhydride based on the amount. More preferred are 5 to 80 mol% of cyclohexanetricarboxylic anhydride, 10 to 90 mol% of trimellitic anhydride, and 5 to 30 mol% of benzophenone-3,3 ', 4,4'-tetracarboxylic dianhydride. The amount of cyclohexanetricarboxylic anhydride, trimellitic anhydride, and benzophenone-3,3 ', 4,4'-tetracarboxylic dianhydride used is based on the molar amount of all raw materials constituting the polyimide resin. Are preferably 2 to 60 mol%, 2 to 60 mol% and 2 to 60 mol%, respectively.

  In producing the linear polyimide (a1) used in the present invention, for example, a polyisocyanate compound and a polycarboxylic acid anhydride containing an acid anhydride react with each other. The ratio (ma) / (mb) of the total number of moles (mb) of the isocyanate groups in the polyisocyanate compound (ma) and the total number of moles of hydroxyl groups and carboxyl groups in the acid anhydride (ma) is determined by the polyimide resin having a large molecular weight. A ratio of 0.7 to 1.2 is preferable, and a ratio of 0.8 to 1.2 is more preferable because it is a polyimide resin from which a cured product that is easy to obtain and has excellent mechanical properties can be obtained. Moreover, since it is easy to obtain the polyimide resin which is excellent in storage stability, the (ma) / (mb) is more preferably in the range of 0.9 to 1.1.

  In the case of producing in a one-step reaction in the production method, for example, a reaction vessel is charged with a polyisocyanate compound and a compound having an acid anhydride group, and the reaction is allowed to proceed while decarboxylation by heating while stirring. .

  The reaction temperature can be in the range of 50 ° C. to 250 ° C., and is preferably performed at a temperature of 70 ° C. to 180 ° C. in terms of reaction rate and prevention of side reactions.

  The reaction is preferable because the stability of the resulting polyimide resin is improved when the reaction is performed until almost all isocyanate groups have reacted. Moreover, you may make it react by adding an alcohol and a phenol compound with respect to the isocyanate group which remains a little.

  In the manufacturing method, it is preferable to use an organic solvent because a uniform reaction can proceed. Here, the organic solvent may be present after being present in the system in advance or may be introduced in the middle. In order to maintain an appropriate reaction rate, the proportion of the organic solvent in the system is preferably 98% by weight or less, more preferably 10 to 90% by weight of the reaction system. As such an organic solvent, since a compound containing an isocyanate group is used as a raw material component, an aprotic polar organic solvent having no active proton such as a hydroxyl group or an amino group is preferable.

  As the aprotic polar organic solvent, for example, polar organic solvents such as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, sulfolane, and γ-butyrolactone can be used. In addition to the above solvents, ether solvents, ester solvents, ketone solvents, petroleum solvents and the like may be used as long as they are soluble. Various solvents may be mixed and used.

  As the organic solvent used for the production of the polyimide resin (a1) used in the present invention, especially the odor and toxicity of the solvent, the reduction of the residual solvent amount when the coating film is dried and cured, and the moisture absorption amount of the coating film is reduced. For these reasons, use of γ-butyrolactone is preferred. Moreover, the structure which melt | dissolves in (gamma) -butyrolactone also in the polyimide resin obtained is preferable. As a polyimide resin which is dissolved in such γ-butyrolactone and has good performance in various physical properties (heat resistance, low linear expansion coefficient, mechanical properties), for example, 4,4′-diisocyanate-3,3′-dimethyl-1 , 1'-biphenyl diisocyanate and 4,4'-diphenylmethane diisocyanate containing diisocyanate compound are used to react cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride with trimellitic anhydride It is obtained by letting At this time, part or all of 4,4'-diphenylmethane diisocyanate may be replaced with toluene diisocyanate.

  4,4′-diisocyanate-3,3′-dimethyl-1,1′-biphenyl, 4,4-diphenylmethane diisocyanate, cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride at this time The proportion of trimellitic anhydride used is preferably 2 to 60 mol% based on the molar amount of all raw materials constituting the polyimide resin.

  Furthermore, a polyimide resin which is dissolved in such γ-butyrolactone and has good performance in various physical properties (heat resistance, low linear expansion coefficient, mechanical properties) is 4,4′-diisocyanate-3,3′-dimethyl-1, 1'-biphenyl, 4,4-diphenylmethane diisocyanate, cyclohexane-1,3,5-tricarboxylic acid-3,4-anhydride, trimellitic anhydride, benzophenone-3,3 ', 4,4' -It can obtain preferably by making it react with tetracarboxylic dianhydride. 4,4-diphenylmethane diisocyanate, cyclohexane-1,3,5-tricarboxylic acid-3,4-anhydride, trimellitic anhydride, and benzophenone-3,3 ', 4,4'-tetracarboxylic The use ratio of the acid dianhydride is preferably 2 to 60 mol% based on the molar amount of all raw materials constituting the polyimide resin. At this time, part or all of 4,4'-diphenylmethane diisocyanate may be replaced with toluene diisocyanate.

  Examples of ether solvents that can be used in the production of the polyimide resin (a1) include ethylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol di Polyethylene glycol dialkyl ethers such as butyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether; ethylene glycol such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate Polyethylene glycol monoalkyl such as diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, triethylene glycol monobutyl ether acetate Ether acetates;

Propylene glycol dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether; dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol Polypropylene glycol dialkyl ethers such as propylene glycol dibutyl ether; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate; Polypropylene glycol monoalkyl ether acetate such as triglycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monobutyl ether acetate, tripropylene glycol monomethyl ether acetate, tripropylene glycol monoethyl ether acetate, tripropylene glycol monobutyl ether acetate Dialkyl ethers of copolymerized polyether glycols such as low molecular weight ethylene-propylene copolymers; monoacetate monoalkyl ethers of copolymerized polyether glycols; alkyl esters of copolymerized polyether glycols; Examples include ether glycol monoalkyl esters and monoalkyl ethers. It is.

  Examples of the ester solvent include ethyl acetate and butyl acetate. Examples of the ketone solvent include acetone, methyl ethyl ketone, and cyclohexanone. In addition, as the petroleum solvent, it is also possible to use toluene, xylene, other high-boiling aromatic solvents, and aliphatic and alicyclic solvents such as hexane and cyclohexane.

  The ratio of the organic solvent in the system in the case of using the organic solvent when producing the polyimide resin (a1) is preferably 98% by weight or less of the reaction system, and more preferably 40 to 90% by weight.

  Whether or not the polyimide resin (a1) is dissolved in an organic solvent is determined by adding the concentration of the polyimide resin of the present invention to the organic solvent to 10% by mass and allowing to stand at 25 ° C. for 7 days, and then visually. This can be done by observing the appearance.

  Examples of the monoepoxy compound (a2) used in the present invention include N-glycidyl phthalimide, O-phenylphenol glycidyl ether, phenyl glycidyl ether, alkylphenyl glycidyl ether, alkyl glycidyl ether, alkyl glycidyl ester, and alkylphenol alkylene oxide adducts. Examples thereof include glycidyl ether, α-olefin oxide, monoepoxy fatty acid alkyl ester, and the like.

  Examples of the alkylphenyl glycidyl ether include cresyl glycidyl ether, butyl glycidyl ether, and nonyl glycidyl ether. Examples of the alkyl glycidyl ether include butyl glycidyl ether and 2-ethylhexyl glycidyl ether.

   Examples of the alkyl glycidyl ester include the following general formula:

（但し、Ｒは炭素原子数１〜２５のアルキル基、好ましくは炭素原子数１０〜１５のアルキル基である。）
で示される化合物が挙げられる。

(However, R is an alkyl group having 1 to 25 carbon atoms, preferably an alkyl group having 10 to 15 carbon atoms.)
The compound shown by these is mentioned.

  Furthermore, examples of the glycidyl ether of the alkylphenol alkylene oxide adduct include a glycidyl ether of a compound obtained by adding an alkylene oxide such as ethylene oxide or propylene oxide to a lower alkylphenol such as butylphenol, and specific examples include ethylene glycol monophenyl. Glycidyl ether of ether, glycidyl ether of polyethylene glycol monophenyl ether, glycidyl ether of propylene glycol monophenyl ether, glycidyl ether of polypropylene glycol monophenyl ether, glycidyl ether of propylene glycol mono (pt-butyl) phenyl ether, ethylene glycol And glycidyl ether of monononylphenyl ether That.

  Examples of the α-olefin oxide include compounds obtained by oxidizing olefins such as alpha olefin oxide-168 [Adeka Argas Chemical Co., Ltd. product] and alpha olefin oxide-124 [Adeka Argas Chemical Co., Ltd. product].

  The monoepoxy fatty acid alkyl ester is, for example, a compound obtained by epoxidizing an unsaturated group of an alcohol ester of an unsaturated fatty acid, such as an epoxidized oleic acid butyl ester, the following structural formula

で示される化合物、エポキシ化オレイン酸オクチルエステル等が挙げられる。これらのモノエポキシ化合物は単独で用いても２種以上を併用しても差し支えない。

And epoxidized oleic acid octyl ester and the like. These monoepoxy compounds may be used alone or in combination of two or more.

  Sealing the carboxyl group of the linear polyimide resin (a1) with the monoepoxy compound (a2) is not particularly limited as long as the carboxyl and epoxy react with each other. For example, the carboxyl group is heated in a heat atmosphere of 100 ° C. or higher. Can be reacted with epoxy. In the monoepoxy resin, it is preferable to react 100 to 50% of the solid content acid value of (a1) from the viewpoint of melt adhesion of the B stage film, and it is more preferable to react 100 to 80%. .

  Among the monoepoxy compounds (a2) used in the present invention, one or more monoepoxy compounds selected from the group consisting of phenyl glycidyl ether, N-glycidyl phthalimide and O-phenylphenol glycidyl ether are cured products having a low coefficient of thermal expansion. Since it becomes the thermosetting resin composition obtained, it is preferable.

  The epoxy resin (B) used in the present invention preferably has two or more epoxy groups in the molecule. Examples of such epoxy resins include biphenyl type epoxy resins; naphthalene type epoxy resins; phenol novolac epoxy resins, cresol novolac type epoxy resins, bisphenol type novolak and other novolac type epoxy resins; and dicyclopentadiene and various phenols. Epoxidized products of various dicyclopentadiene-modified phenol resins obtained; epoxy resin having a fluorene skeleton; 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide, etc. Phosphorus-containing epoxy resin synthesized; Aliphatic epoxy resin such as neopentyl glycol diglycidyl ether and 1,6-hexanediol diglycidyl ether; 3,4-epoxycyclohexylmethyl-3 - 4-epoxycyclohexane carboxylate, bis (3,4-epoxy human cyclohexyl) alicyclic epoxy resins such as adipate; such as such as triglycidyl isocyanurate heterocycle-containing epoxy resins. Among them, at least one epoxy resin selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, and naphthalene type epoxy resin is obtained. It is preferable because the composition is excellent in meltability at low temperature while being expanded.

  The content of the epoxy resin (B) is 30 to 200% by mass with respect to 100 parts by mass of the polyimide resin (A), and the cured product has a low linear expansion, and has excellent thermosetting properties at low temperatures. The resin composition is preferably obtained, more preferably 50 to 150% by mass, and still more preferably 60 to 100% by mass.

  The curing agent (C) for the epoxy resin used in the present invention is not particularly limited, and various examples such as an imidazole compound, an amine compound, an amide compound, an acid anhydride compound, and a phenol compound. Can be used.

  Examples of the imidazole compound include 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecyl, and imidazo. Lithium trimellitate, 2,4-diamino-6- [2'-methyl, imidazolyl- (1 ')]-ethyl-s-triazine, 2-phenyl-4,5-dihydroxymethylimidazole, 2-methylimidazoline, etc. Can be given.

  Examples of the amine compound include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF3 -amine complex, and guanidine derivatives.

  Examples of the amide compound include polyamide resins synthesized from dimer of dicyandiamide and linolenic acid and ethylenediamine.

  Examples of the acid anhydride compounds include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexa And hydrophthalic anhydride.

  Examples of the phenolic compound include phenol novolac resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin-modified phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin (commonly known as zylock resin), naphthol aralkyl resin, trimethylol methane. Resin, tetraphenylolethane resin, naphthol novolac resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenol resin (polyhydric phenol compound in which phenol nucleus is linked by bismethylene group), biphenyl-modified Naphthol resins (polyvalent naphthol compounds with phenolic nuclei linked by bismethylene groups), aminotriazine-modified phenolic resins (melamine and benzogua) Min polyhydric phenol compound phenol nuclei are connected by, etc.) the polyhydric phenol compound such as, and and modified products thereof. The curing agent (C) used in the present invention is not limited to the above compound. Moreover, a hardening | curing agent (C) may be used independently and may be used together 2 or more types.

  The blending amount of the curing agent (C) for the epoxy resin is not particularly limited, but it is used in combination with the epoxy resin (A) and, if necessary, from the viewpoint of good mechanical properties of the resulting cured product. The amount by which the active groups in the curing agent are 0.7 to 1.5 equivalents is preferable with respect to a total of 1 equivalent of epoxy groups with other epoxy resins.

  Furthermore, the thermosetting polyimide resin composition of the present invention includes polyester, phenoxy resin, PPS, PPE, acrylic rubber, acrylonitrile rubber, nitrile butadiene rubber, styrene butadiene rubber, polyarylene resin and other binder resins, phenol resin, melamine resin, Curing agents such as alkoxysilane curing agents, polybasic acid anhydrides, cyanate compounds or reactive compounds, melamine, dicyandiamide, guanamine and derivatives thereof, imidazoles, amines, phenols having one hydroxyl group, organic phosphines, Curing catalysts and curing accelerators such as phosphonium salts, quaternary ammonium salts, photocationic catalysts, fillers, and other additives such as antifoaming materials, leveling agents, slip agents, wetting improvers, anti-settling agents, flame retardants, oxidation Inhibitor, ultraviolet It is also possible to add absorbers.

  The thermosetting polyimide resin composition of the present invention is preferably a composition having a linear expansion coefficient of 60 ppm / ° C. or lower when the composition is cured.

  In addition, various fillers, organic pigments, inorganic pigments, extender pigments, rust inhibitors and the like can be added to the thermosetting polyimide resin composition of the present invention as necessary. These may be used alone or in combination of two or more.

  Examples of the filler include barium sulfate, barium titanate, silicon oxide powder, finely divided silicon oxide, silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, mica, and alumina. Is mentioned.

  As the filler, those having various particle sizes can be used, and can be added to such an extent that the physical properties of the present resin and its composition are not impaired. Such an appropriate amount is in the range of about 5 to 80% by mass, and preferably used after being uniformly dispersed. As a dispersion method, it is possible to carry out dispersion by a known roll, bead mill, high-speed dispersion or the like, and the surface of the particles may be modified in advance with a dispersion treatment agent.

  Examples of the organic pigment include azo pigments; copper phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green, and quinacridone pigments.

  Examples of the inorganic pigment include chromates such as chrome lead, zinc chromate and molybdate orange; ferrocyanides such as bitumen, titanium oxide, zinc white, bengara, iron oxide; metal oxides such as chromium carbide green, Cadmium yellow, cadmium red; metal sulfides such as mercury sulfide; selenides; sulfates such as lead sulfate; silicates such as ultramarine; carbonates, cobalt biored; phosphates such as manganese purple; aluminum powder, zinc dust Metal powders such as brass powder, magnesium powder, iron powder, copper powder and nickel powder; carbon black and the like.

  In addition, any of other coloring, rust prevention, and extender pigments can be used. These may be used alone or in combination of two or more.

  The cured product of the present invention is obtained by curing the thermosetting polyimide resin composition of the present invention. Specifically, for example, the thermosetting polyimide resin composition of the present invention includes a cured product that is cured by heating at 100 to 300 ° C. after coating on a substrate.

  The substrate used in the method for forming the coating film can be used without any particular limitation. Examples of the substrate include plastic, metal, wood, glass, inorganic material, and composite materials thereof. There is no restriction | limiting in particular as a shape of a base material, A sheet | seat, a film-like thing, a chip | tip shape, a solid shape, etc. can be illustrated.

  The interlayer adhesive film for printed wiring boards of the present invention is characterized by having a layer formed of a thermosetting polyimide resin composition on a carrier film. Such an adhesive film can illustrate the form of the film (adhesive film) which consists of a layer (A layer) and a support body film (B layer) of the thermosetting polyimide resin composition of this invention, for example.

  The adhesive film is prepared according to various methods, for example, preparing a resin varnish obtained by dissolving the thermosetting polyimide resin composition of the present invention in an organic solvent, applying the resin varnish to a support film, and heating or blowing hot air, etc. Thus, the organic solvent can be dried to form a resin composition layer.

  The support film (B layer) serves as a support when the adhesive film is produced, and is finally peeled off or removed in the production of the printed board. Examples of the support film include polyolefins such as polyethylene and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyesters such as polyethylene naphthalate, polycarbonate, and release paper and copper foil. The metal foil etc. can be mentioned. In addition, when using copper foil as a support body film, it can remove by etching with etching liquid, such as ferric chloride and cupric chloride. The support film may be subjected to a release treatment in addition to a mat treatment and a corona treatment, but it is more preferable that the release treatment is performed in consideration of releasability. Although the thickness of a support film is not specifically limited, Usually, it is 10-150 micrometers, Preferably it is used in 25-50 micrometers.

  Organic solvents for preparing the varnish include, for example, ketones such as acetone, methyl ethyl ketone, cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, cellosolve, butyl Examples thereof include carbitols such as carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and gamma butyrolactone. Two or more organic solvents may be used in combination.

  The drying conditions are not particularly limited, but the drying is performed so that the content of the organic solvent in the resin composition is usually 5% by mass or less, preferably 3% by mass or less. The specific drying conditions vary depending on the curability of the resin composition and the amount of the organic solvent in the varnish. It can be dried to some extent. Those skilled in the art can appropriately set suitable drying conditions by simple experiments.

  The thickness of the resin composition layer (A layer) can usually be in the range of 5 to 500 μm. The preferred range of the thickness of the A layer varies depending on the use of the adhesive film, and when used for manufacturing a multilayer flexible circuit board by the build-up method, the thickness of the conductor layer forming the circuit is usually 5 to 70 μm. The thickness of the A layer corresponding to the layer is preferably in the range of 10 to 100 μm.

  The A layer may be protected with a protective film. By protecting with a protective film, it is possible to prevent dust and the like from being attached to the surface of the resin composition layer and scratches. The protective film is peeled off during lamination. As the protective film, the same material as the support film can be used. Although the thickness of a protective film is not specifically limited, Preferably it is the range of 1-40 micrometers.

  The adhesive film obtained using the thermosetting polyimide resin composition of the present invention can be suitably used particularly for the production of a multilayer printed board. Below, the method to manufacture a printed circuit board is demonstrated. The adhesive film obtained by using the thermosetting polyimide resin composition of the present invention can be suitably laminated on a printed board with a vacuum laminator. The printed circuit board used here is mainly a conductor layer patterned on one or both sides of a substrate such as a fiber reinforced prepreg such as an epoxy substrate or a glass epoxy substrate, a polyester substrate, a polyimide substrate, a polyamideimide substrate, or a liquid crystal polymer substrate. (Circuit) As a matter of course, a multilayer printed circuit board in which a circuit and an insulating layer are alternately formed and a circuit is formed on one side or both sides can be used for further multilayering. In addition, from the viewpoint of adhesion of the insulating layer to the circuit board, the surface of the circuit should have been previously roughened with a surface treatment agent such as hydrogen peroxide / sulfuric acid or MEC Etch Bond (MEC Co., Ltd.). preferable.

  Commercially available vacuum laminators include, for example, a vacuum applicator manufactured by Nichigo Morton, a vacuum pressurizing laminator manufactured by Meiki Seisakusho, a roll dry coater manufactured by Hitachi Techno Engineering Co., Ltd., Hitachi AIC ( A vacuum laminator manufactured by Co., Ltd. can be mentioned.

In the lamination, when the adhesive film has a protective film, the protective film is removed, and then the adhesive film is pressure-bonded to the circuit board while being pressurized and heated. The laminating conditions include pre-heating the adhesive film and the circuit board as required, laminating at a pressure of preferably 70 to 140 ° C., a pressure of pressure of preferably 1 to 11 kgf / cm ² and laminating under a reduced pressure of an air pressure of 20 mmHg or less. preferable. The laminating method may be a batch method or a continuous method using a roll.

  After laminating the adhesive film on the circuit board, it is cooled to around room temperature and the support film is peeled off. Next, the thermosetting polyimide resin composition laminated on the circuit board is cured by heating. The conditions for heat curing are usually selected in the range of 150 to 220 ° C. for 20 to 180 minutes, more preferably in the range of 160 to 200 ° C. for 30 to 120 minutes. When the support film has a release treatment or a release layer such as silicon, the support film can be peeled after the thermosetting polyimide resin composition is heat-cured or after heat-curing and punching.

  After the insulating layer, which is a cured product of the thermosetting polyimide resin composition, is formed, holes are drilled in the circuit board by drilling, laser, plasma, or a combination thereof as necessary to form via holes and through holes. It may be formed. In particular, drilling with a laser such as a carbon dioxide laser or a YAG laser is generally used.

  Next, surface treatment of the insulating layer (cured product of thermosetting polyimide resin composition) is performed. The surface treatment can employ a method used in a desmear process, and can be performed in a form that also serves as a desmear process. As a chemical used in the desmear process, an oxidizing agent is generally used. Examples of the oxidizing agent include permanganate (potassium permanganate, sodium permanganate, etc.), dichromate, ozone, hydrogen peroxide / sulfuric acid, nitric acid, and the like. Preferably, an alkaline permanganate solution (for example, potassium permanganate, sodium hydroxide aqueous solution of sodium permanganate), which is an oxidizer widely used for roughening the insulating layer in the production of multilayer printed wiring boards by the build-up method. It is preferable to carry out the treatment using A treatment with a swelling agent can also be performed before the treatment with the oxidizing agent. Further, after the treatment with an oxidizing agent, neutralization treatment with a reducing agent is usually performed.

  After the surface treatment, a conductor layer is formed by plating on the surface of the insulating layer. The conductor layer can be formed by a method combining electroless plating and electrolytic plating. Alternatively, a plating resist having a pattern opposite to that of the conductor layer can be formed, and the conductor layer can be formed only by electroless plating. After the conductor layer is formed, the peel strength of the conductor layer can be further improved and stabilized by annealing at 150 to 200 ° C. for 20 to 90 minutes.

  As a method for forming a circuit by patterning the conductor layer, for example, a subtractive method or a semi-additive method known to those skilled in the art can be used. In the case of the subtractive method, the thickness of the electroless copper plating layer is 0.1 to 3 μm, preferably 0.3 to 2 μm. An electroplating layer (panel plating layer) is formed thereon with a thickness of 3 to 35 μm, preferably 5 to 20 μm, an etching resist is formed, and etching is performed with an etching solution such as ferric chloride or cupric chloride. After forming a conductor pattern by this, a circuit board can be obtained by peeling an etching resist. In the case of the semi-additive method, after forming the electroless copper plating layer with an electroless copper plating layer thickness of 0.1 to 3 μm, preferably 0.3 to 2 μm, a pattern resist is formed, and then the electrolytic copper A circuit board can be obtained by peeling after plating.

  A film in which the support film is replaced with a heat-resistant resin layer (heat-resistant resin film), that is, a film composed of the thermosetting polyimide resin composition layer (A layer) and the heat-resistant resin layer (C layer) of the present invention is flexible. It can be used as a base film for circuit boards. A film composed of the thermosetting polyimide resin composition layer (A layer), heat resistant resin layer (C layer) and copper foil (D layer) of the present invention can be used as a base film of a flexible circuit board. In this case, the base film has a layer structure in the order of A layer, C layer, and D layer. In the base film as described above, the heat-resistant resin layer is not peeled off and constitutes a part of the flexible circuit board.

  A film in which an insulating layer (A ′ layer) made of a cured product of the thermosetting polyimide resin composition of the present invention is formed on a heat-resistant resin layer (C layer) can be used as a base film for a single-sided flexible circuit board. Moreover, it consists of the film which has the layer structure of the order of A 'layer, C layer, and A' layer, and A 'layer, C layer, and copper foil (D layer), and the order of A' layer, C layer, and D layer. Similarly, a film having a layer structure can be used as a base film for a double-sided flexible circuit board.

  Examples of the heat-resistant resin used for the heat-resistant resin layer include a polyimide resin, an aramid resin, a polyamideimide resin, and a liquid crystal polymer. In particular, a polyimide resin and a polyamideimide resin are preferable. Moreover, on the characteristic used for a flexible circuit board, the breaking strength is 100 MPa or more, the breaking elongation is 5% or more, the thermal expansion coefficient between 20 and 150 ° C. is 40 ppm or less, and the glass transition temperature is 200 ° C. or more or the decomposition temperature is 300 ° C. It is preferable to use the above heat resistant resin.

  As the heat-resistant resin satisfying such characteristics, a heat-resistant resin that is commercially available in the form of a film can be suitably used. For example, a polyimide film “Upilex-S” manufactured by Ube Industries, Ltd., Toray DuPont Co., Ltd. ) Polyimide film "Kapton", Kaneka Chemical Co., Ltd. polyimide film "Apical", Teijin Advanced Films Ltd. "Aramika", Kuraray Co., Ltd. liquid crystal polymer film "Bexstar", Sumitomo Bakelite Co., Ltd. A polyether ether ketone film “Sumilite FS-1100C” and the like are known.

  The thickness of the heat-resistant resin layer is usually 2 to 150 μm, preferably 10 to 50 μm. As the heat-resistant resin layer (C layer), a surface-treated layer may be used. Examples of the surface treatment include dry treatment such as mat treatment, corona discharge treatment and plasma treatment, chemical treatment such as solvent treatment, acid treatment and alkali treatment, sand blast treatment and mechanical polishing treatment. In particular, from the viewpoint of adhesion to the A layer, it is preferable that plasma treatment is performed.

  A base film for a single-sided flexible circuit board comprising an insulating layer (A ′) and a heat-resistant resin layer (C) can be produced as follows. First, similarly to the adhesive film described above, a resin varnish prepared by dissolving the thermosetting polyimide resin composition of the present invention in an organic solvent is prepared, this resin varnish is applied on a heat-resistant resin film, and heating or hot air blowing is performed. To dry the organic solvent to form a thermosetting polyimide resin composition layer. Conditions such as the organic solvent and drying conditions are the same as those for the adhesive film. The thickness of the resin composition layer is preferably in the range of 5 to 15 μm.

  Next, the thermosetting polyimide resin composition layer is dried by heating to form an insulating layer of the thermosetting polyimide resin composition. The conditions for heat curing are usually selected in the range of 150 to 220 ° C. for 20 to 180 minutes, more preferably in the range of 160 to 200 ° C. for 30 to 120 minutes.

  The production of a base film of a double-sided flexible circuit board film consisting of three layers of an insulating layer (A ′ layer), a heat-resistant resin layer (C) layer and a copper foil (D layer) is made of a heat-resistant resin layer (C layer) and a copper foil. A resin composition may be formed on a copper-clad laminated film made of (D layer) and manufactured in the same manner as described above. Examples of the copper clad laminated film include a cast method two-layer CCL (Copper-clad laminate), a sputtering method two-layer CCL, a laminate method two-layer CCL, and a three-layer CCL. The thickness of the copper foil is preferably 12 μm or 18 μm.

  Commercially available two-layer CCL includes Espanex SC (manufactured by Nippon Steel Chemical Co., Ltd.), Neoprex I <CM>, Neoprex I <LM> (Mitsui Chemicals), S'PERFLEX (Sumitomo Metal Mining Co., Ltd.) Nikaflex F-50VC1 (manufactured by Nikkan Kogyo Co., Ltd.) and the like are mentioned as the commercially available three-layer CCL.

  The production of a base film for a double-sided flexible circuit board film comprising three layers of an insulating layer (A ′ layer), a heat-resistant resin layer (C layer) and an insulating layer (A ′ layer) can be carried out as follows. First, in the same manner as the adhesive film described above, a resin varnish prepared by dissolving the thermosetting polyimide resin composition of the present invention in an organic solvent is prepared, and this resin varnish is applied on a support film and heated or blown with hot air or the like. The organic solvent is dried to form a resin composition layer. Conditions such as the organic solvent and drying conditions are the same as those for the adhesive film. The thickness of the resin composition layer is preferably in the range of 5 to 15 μm.

  Next, this adhesive film is laminated on both surfaces of the heat resistant resin film. Lamination conditions are the same as described above. Moreover, if the resin composition layer is previously provided on one side of the heat-resistant film, the lamination may be only on one side. Next, the resin composition layer is cured by heating to form an insulating layer that is a layer of the resin composition. The conditions for heat curing are usually selected in the range of 150 to 220 ° C. for 20 to 180 minutes, more preferably in the range of 160 to 200 ° C. for 30 to 120 minutes.

  A method for producing a flexible circuit board from the base film for the flexible circuit board will be described. In the case of a base film composed of an A ′ layer, a C layer, and an A ′ layer, first, after heat curing, a circuit board is drilled by a method such as drilling, laser, or plasma to form a through hole for conduction on both sides. . In the case of a base film composed of an A ′ layer, a C layer, and a D layer, holes are formed by the same method to form via holes. In particular, drilling with a laser such as a carbon dioxide laser or a YAG laser is generally used.

  Next, a surface treatment of the insulating layer (resin composition layer) is performed. About surface treatment, it is the same as that of the case of the adhesive film mentioned above. After the surface treatment, a conductor layer is formed by plating on the surface of the insulating layer. The formation of the conductor layer by plating is the same as in the case of the adhesive film described above. After the conductor layer is formed, the peel strength of the conductor layer can be further improved and stabilized by annealing at 150 to 200 ° C. for 20 to 90 minutes.

  Next, the conductor layer is patterned to form a circuit to obtain a flexible circuit board. When a base film composed of an A layer, a C layer, and a D layer is used, a circuit is also formed on the copper foil that is the D layer. As a circuit formation method, for example, a subtractive method or a semi-additive method known to those skilled in the art can be used. Details are the same as in the case of the adhesive film described above.

  The single-sided or double-sided flexible circuit board obtained in this way can be produced as a multilayer flexible circuit board by using the adhesive film of the present invention, for example, as described above.

  The resin composition of the present invention is also useful as a material for forming a stress relaxation layer between a semiconductor and a substrate substrate. For example, in the same manner as described above, all or part of the uppermost insulating layer of the substrate substrate is formed by the adhesive film obtained by using the resin composition of the present invention, and the resin is connected by connecting the semiconductor. A semiconductor device in which a semiconductor and a substrate substrate are bonded via a cured product of the composition can be manufactured. In this case, the thickness of the resin composition layer of the adhesive film is appropriately selected within a range of 10 to 1000 μm. The resin composition of the present invention can form a conductor layer by plating, and a circuit pattern can also be produced by simply forming a conductor layer by plating on an insulating layer for stress relaxation provided on a substrate substrate. Is possible.

  EXAMPLES Next, an Example is shown and this invention is demonstrated further in detail. Unless otherwise specified, “parts” and “%” are based on weight.

Synthesis Example 1 [Synthesis of Polyimide Resin (A)]
In a flask equipped with a stirrer, a thermometer and a condenser, 213.2 g of DMAC (dimethylacetamide), 6.29 g (0.036 mol) of TDI (tolylene diisocyanate), TODI (4,4′-diisocyanate-3,3 '-Dimethyl-1,1'-biphenyl) 37.8 g (0.143 mol), TMA (trimellitic anhydride) 29.0 g (0.151 mol), BTDA (benzophenone-3,3', 4,4) ′ -Tetracarboxylic dianhydride) and 12.2 g (0.038 mol) were added, the temperature was raised to 150 ° C. over 1 hour while paying attention to heat generation while stirring, and the reaction was carried out at this temperature for 5 hours. I let you. The reaction proceeded with the foaming of carbon dioxide, and the system became a brown transparent liquid. A polyimide resin solution (resin composition in which the polyimide resin was dissolved in DMAC) having a resin solid content of 20% with a viscosity of 2 Pa · s at 25 ° C. and a solution acid value of 16 (KOHmg / g) was obtained. This is abbreviated as polyimide resin (a1) solution. In addition, the solid content acid value of the resin calculated from the value was 64 (KOHmg / g). Moreover, it was the weight average molecular weight 10,000 as a result of the measurement of a gel permeation chromatography (GPC).

  The obtained polyimide resin (a1) solution was coated on a KBr plate, and the infrared absorption spectrum of the sample in which the solvent was volatilized was measured. As a result, 2270 cm-1 which is the characteristic absorption of the isocyanate group completely disappeared, and 725 cm- Characteristic absorption of the imide ring was confirmed at 1, 1780 cm <-1> and 1720 cm <-1>. The amount of carbon dioxide generated was 15.8 g (0.36 mol), which was monitored by the change in the flask content weight. From this, it is concluded that the total amount of 0.36 mol, which is the total amount of isocyanate groups, has been converted to imide bonds and amide bonds.

  Table 1 shows the blending amount of the raw material of the polyimide resin (a1), the content of the biphenyl skeleton, the logarithmic viscosity, the weight average molecular weight, and the solid content acid value.

  A total of 0.08 g of triphenylphosphine and 12.2 g of deconal EX-141 (phenylglycidyl ether epoxy equivalent 151 g / eq) are charged to the total amount of the polyimide resin (a1) solution, and reacted at 160 ° C. for 4 hours to obtain a resin solid content. A polyimide resin solution having a 28% viscosity of 2 Pa · s and a solution acid value of 2.0 KOHmg / g was obtained. This is abbreviated as polyimide resin (A1) solution.

Synthesis Examples 2-5 and 7-9 (same as above)
Polyimide resins (a1) to (a5) and polyimide resins (a7) to (a9) were obtained in the same manner as in Synthesis Example 1 except that the blending ratios shown in Table 1 were used. Polyimide resins (a1) to (a5) and polyimide resins (a7) to (a9) were obtained in the same manner as in Synthesis Example 1 except that the total amount of these polyimide resins and the monoepoxy compound shown in Table 1 were used.

Synthesis example 6 (same as above)
Polyimide resin in the same manner as in Synthesis Example 1 except that BPDA (BPDA: biphenyl-3,3 ′, 4,4′-tetracarboxylic anhydride) is used instead of BTDA and the blending ratio shown in Table 1 is used. A solution of (A6) was obtained.

Footnotes in Table 1 Denacol EX-141: Phenyl glycidyl ether Denacol EX-192: Alkyl (C11-C13) glycidyl ether Denacol EX-731: N-glycidyl phthalimide OPP-G: O-phenylphenol glycidyl ether

Synthesis Example 10 [Comparative Polyimide Resin (Synthesis of A ′)]
A flask equipped with a stirrer, a thermometer and a condenser was charged with 888.8 g of GBL (gamma-butyrolactone), 57.5 g (0.23 mol) of MDI (diphenylmethane diisocyanate), DMBPDI (4,4′-diisocyanate-3,3 ′). -Dimethyl-1,1'-biphenyl) 59.4 g (0.225 mol), TMA (trimellitic anhydride) 67.2 g (0.35 mol) and TMA-H (cyclohexane-1,3,4-tricarboxylic acid) Acid-3,4-anhydride) 29.7 g (0.15 mol), and while stirring, paying attention to heat generation, the temperature was raised to 80 ° C., and dissolved and reacted at this temperature for 1 hour. The temperature was further raised to 160 ° C. over 2 hours, and the reaction was carried out at this temperature for 5 hours. The reaction proceeded with the foaming of carbon dioxide, and the system became a brown transparent liquid. A solution of a polyimide resin (A′1) having a viscosity of 7 Pa · s at 25 ° C. and a resin solid content of 17% and a solution acid value of 5.3 (KOH mg / g) was obtained. The solid content acid value of the resin was 31.2 (KOH mg / g). Moreover, it was the weight average molecular weight 34000 as a result of the measurement of a gel permeation chromatography (GPC).

As a result of coating the obtained polyimide resin (A′1) solution on a KBr plate and measuring the infrared absorption spectrum of the sample in which the solvent was volatilized, 2270 cm−1, which is the characteristic absorption of the isocyanate group, completely disappeared. Characteristic absorption of the imide ring was confirmed at 725 cm ⁻¹ , 1780 cm ⁻¹ and 1720 cm ⁻¹ . The amount of carbon dioxide generated was 40 g (0.91 mol), as monitored by the change in the flask content weight. From this, it is concluded that the total amount of 0.91 mol, which is the total amount of isocyanate groups, has been converted to imide bonds and amide bonds. Furthermore, it is a polyimide resin represented by the following general formula in which the composition ratio of MDI: DMBPDI: TMA: TMA-H, which is a raw material as a result of analysis by C13-NMR, is 46: 45: 70: 30 molar ratio. confirmed.

但し、上記ポリイミド樹脂中の構造単位であるＡ_１は以下の構造

However, A ₁ is a structural unit of the polyimide resin has the following structure

を有し、Ａ_２は以下の構造

And A ₂ has the following structure:

を有し、Ａ_３は以下の構造

And A ₃ has the following structure:

を有し、Ａ_４は以下の構造

And A ₄ has the following structure:

を有し、Ａ_１：Ａ_２：Ａ_３：Ａ_４＝１３．５：３１．５：１３．８：３２．２（モル比）であった。

And A ₁ : A ₂ : A ₃ : A ₄ = 13.5: 31.5: 13.8: 32.2 (molar ratio).

  It was concluded that the terminal structure of the polyimide resin (X1) has at least one of the following structures from the analysis results and the charging ratio.

  However, * shows the coupling | bonding point to a molecular principal chain.

Synthesis example 11 (same as above)
A flask equipped with a stirrer, a thermometer and a condenser was charged with 2070 g of GBL, 62.5 g (0.25 mol) of MDI, 195.4 g (0.74 mol) of DMBPDI, 99.8 g (0.52 mol) of TMA and BTDA. (Benzophenone tetracarboxylic acid anhydride) 32.2 g (0.1 mol) and TMA-H 59.4 g (0.3 mol) were charged, and the temperature was raised to 80 ° C. while paying attention to heat generation while stirring. The mixture was dissolved and reacted at this temperature for 1 hour, further heated to 170 ° C. over 2 hours, and then reacted at this temperature for 5 hours. The reaction proceeded with the foaming of carbon dioxide, and the system became a brown transparent liquid. A solution of a polyimide resin (A'2) having a resin solid content of 16% with a viscosity at 25 ° C of 7 Pa · s and a solution acid value of 2.1 (KOHmg / g) was obtained. The solid content acid value of the resin was 33.1 (KOHmg / g). Moreover, the weight average molecular weight was 44000 by GPC measurement.

Examples 1-11 and Comparative Examples 1-2
The thermosetting resin compositions 1 to 11 and the comparative thermosetting resin compositions 1 'to 2' of the present invention were obtained with the formulations shown in Tables 2 and 3. The meltability of the B-staged cured product obtained from the obtained composition, melt adhesion, and dimensional stability of the completely cured product were evaluated. The evaluation method is shown below. The evaluation results are shown in Tables 2 and 3.

-Evaluation of meltability of B-staged cured product Create adhesive film
The thermosetting resin composition is uniformly applied on a PET film (thickness 125 μm) with an applicator so that the thickness of the resin composition layer after drying is 25 μm, and dried at 100 ° C. for 5 minutes to form an adhesive film Got.

2. Evaluation Method The above adhesive film was pressed onto a PET film at 120 ° C. × 5 MPa × 3 minutes, the degree of spread of the adhesive layer was observed, and evaluation was performed according to the following criteria.
(Double-circle): The area after a press was more than 150% increase with respect to the area before a press.
(Circle): The area after a press was 60 to 150% with respect to the area before a press.
(Triangle | delta): The area after a press was 30 to 60% increase with respect to the area before a press. X: The area after a press was 30% or less increase with respect to the area before a press.

-Evaluation of melt adhesion of B-staged cured product Create adhesive film
Next, the thermosetting resin composition is uniformly applied on a PET film (thickness 125 μm) with an applicator so that the thickness of the resin composition layer after drying is 25 μm, and dried at 100 ° C. for 5 minutes. An adhesive film was obtained.

2. Melt adhesion test of adhesive film The above-mentioned adhesive film is in contact with copper on an electrolytic copper foil (thickness 18 μm, surface roughness: M surface Rz 7.4 μm, S surface Ra 0.21 μm) heated to 120 ° C. in advance. Thus, the melt adhesion was evaluated. Those requiring pressure for fusion bonding were hot-pressed at a pressure of 5 MPa for 1 minute. Thereafter, the PET film was peeled off, and the resin composition was further cured by heating at 200 ° C. for 60 minutes. The test piece was subjected to a tape peeling test in accordance with JIS K 5400 8.5.2 (adhesive cross-cut tape method), and the melt adhesion was evaluated according to the following five evaluation criteria.

5: The resin melted without applying pressure was sufficiently spread and adhered to the surface of the electrolytic copper foil, and after the main curing, the tape was peeled off and the area of the defective portion was less than 5% with respect to the test execution area.
It can be melt-bonded at a pressure of 4: 5 MPa. After the main curing, the tape is peeled off and the area of the defect portion is less than 5% with respect to the test execution area.
It can be melt-bonded at a pressure of 3: 5 MPa, and after the main curing, the tape is peeled off so that the area of the defect portion is 5% or more with respect to the test execution area.
2: Partially melt-bonded at a pressure of 5 MPa, but the area of the melt-bonded part is less than 50%.
1: No melt adhesion at a pressure of 0.1 MPa.

-Evaluation of dimensional stability of hardened | cured material The said evaluation was performed by evaluating the linear expansion coefficient of hardened | cured material.
1. Preparation of test piece The thermosetting resin composition was coated on a mirror surface aluminum substrate so that the film thickness of the coating film obtained after curing was 30 μm. Next, this coated plate was dried with a dryer at 50 ° C. for 30 minutes, with a dryer at 100 ° C. for 30 minutes, and with a dryer at 200 ° C. for 60 minutes to form a coating film (film). After cooling to room temperature, the coating film (film) was cut into a predetermined size, isolated from the substrate, and used as a measurement sample.

2. Method for measuring linear expansion coefficient
Using a thermal analysis system TMA-SS6000 manufactured by Seiko Electronics Co., Ltd., measurement was performed by the TMA (Thermal Mechanical Analysis) method under the conditions of a sample length of 10 mm, a heating rate of 10 ° C./min, and a load of 30 mN. The linear expansion coefficient was obtained by using a second run after the first run of 300 ° C., and the temperature range used was determined from the displacement of the sample length at 20 to 150 ° C. The smaller the linear expansion coefficient, the better the dimensional stability.

Footnotes in Table 2 The amount of raw materials is converted to solid content.

Table footnote TDI: 2,4-tolylene diisocyanate TODI: 4,4'-diisocyanate-3,3'-dimethyl-1,1'-biphenyl TMA: trimellitic anhydride BTDA: benzophenone tetracarboxylic anhydride BPDA: Biphenyl-3,3 ', 4,4'-tetracarboxylic anhydride HCA-HQ: 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide HP-4710 : Epicron HP-4710 (naphthalene type epoxy resin) manufactured by DIC Corporation
N-680: Epicron N-680 (cresol novolac type epoxy resin) manufactured by DIC Corporation
2E4MZ: Cure Sole 2E4MZ (2-ethyl-4-methylimidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd.

Claims (10)

  Polyimide resin having a weight average molecular weight of 4,000 to 60,000 and a carboxyl group of a linear polyimide resin (a1) having a carboxyl group acid value of 30 to 90 KOHmg / g sealed with a monoepoxy compound (a2) A thermosetting resin composition comprising (A), an epoxy resin (B), and an epoxy resin curing agent (C).   The thermosetting resin composition according to claim 1, wherein the linear polyimide resin (a1) has a weight average molecular weight of 5,000 to 30,000 and an acid value of a carboxyl group of 30 to 90.   The linear polyimide resin (a1) has a biphenyl skeleton directly linked to a 5-membered ring imide skeleton, the content of the biphenyl skeleton is 20 to 45% by mass, and the logarithmic viscosity is 0.2 to 0.00. The thermosetting resin composition according to claim 1, wherein the thermosetting resin composition is an 8 dl / g polyimide resin.   The thermosetting resin composition according to claim 1, wherein the polyimide resin (a1) is a polyimide resin further having a benzophenone structure.   The thermosetting resin composition according to claim 1 or 5, wherein the polyimide resin (a1) is a polyimide resin further having a tolylene structure.   The thermosetting resin composition according to claim 1, wherein the monoepoxy compound (a2) is one or more monoepoxy compounds selected from the group consisting of phenyl glycidyl ether, N-glycidyl phthalimide and O-phenylphenol glycidyl ether.   The epoxy resin (B) is at least one epoxy resin selected from the group consisting of bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, biphenyl type epoxy resins and naphthalene type epoxy resins. Item 8. The thermosetting resin composition according to any one of items 1 to 7.   The thermosetting resin composition according to any one of claims 1 to 7, wherein a content of the epoxy resin (B) is 50 to 150 parts by mass with respect to 100 parts by mass of the polyimide resin (A).   The thermosetting resin composition according to claim 1, wherein the epoxy resin curing agent is trifunctional or higher. The interlayer adhesive film for printed wiring boards which has a layer formed with the thermosetting resin composition of any one of Claims 1-10 on a carrier film.