WO2018221217A1

WO2018221217A1 - Curable resin composition, cured product, adhesive agent, adhesive film, coverlay film and printed wiring board

Info

Publication number: WO2018221217A1
Application number: PCT/JP2018/018892
Authority: WO
Inventors: さやか脇岡; 幸平竹田; 新城　隆; 悠太大當
Original assignee: 積水化学工業株式会社
Priority date: 2017-05-31
Filing date: 2018-05-16
Publication date: 2018-12-06

Abstract

The purpose of the present invention is to provide a curable resin composition which exhibits excellent fluidity prior to curing, and excellent adhesive properties, heat resistance and flexing resistance following curing. In addition, the purpose of the present invention is to provide a cured product of said curable resin composition and an adhesive agent, adhesive film, coverlay film and printed wiring board that are obtained using said curable resin composition. The present invention is a curable resin composition which contains a thermosetting resin, a thermoplastic resin and an imide oligomer. The imide oligomer has a reactive functional group capable of reacting with the thermosetting resin.

Description

Curable resin composition, cured product, adhesive, adhesive film, coverlay film, and printed wiring board

The present invention relates to a curable resin composition having excellent flow characteristics before curing and excellent adhesiveness, heat resistance, and flex resistance after curing. Moreover, this invention relates to the hardened | cured material of this curable resin composition, and the adhesive agent, adhesive film, coverlay film, and printed wiring board which use this curable resin composition.
Moreover, this invention relates to the curable resin composition which can obtain the hardened | cured material which is excellent in storage stability and is excellent in low linear expansion property, adhesiveness, and long-term heat resistance. Moreover, this invention relates to the adhesive agent and adhesive film which use the hardened | cured material of this curable resin composition, and this curable resin composition.
Furthermore, this invention relates to the curable resin composition which is excellent in flexibility and workability before hardening, and is excellent in adhesiveness and heat resistance after hardening. Moreover, this invention relates to the adhesive agent and adhesive film which use the hardened | cured material of this curable resin composition, and this curable resin composition.

A flexible printed wiring board (FPC) usually has a structure in which a copper foil or the like is bonded to one side or both sides of an insulating film such as a polyimide film via an adhesive layer. The adhesive used for the adhesive layer of the flexible printed wiring board is required to have excellent flow characteristics capable of satisfying both sufficient fillability (unevenness embedding property) and leaching prevention during thermocompression bonding. As such an adhesive, for example, Patent Documents 1 to 3 include a thermosetting component such as an epoxy resin, a thermoplastic resin such as acrylic resin, polyamide, and polyester, and a flexible component such as acrylonitrile butadiene rubber. A curable resin composition is disclosed.

On the other hand, long-term heat resistance is required for adhesives with the recent expansion of applications for in-vehicle use. However, the adhesives using the curable resin compositions disclosed in Patent Documents 1 to 3 have insufficient heat resistance.
As an adhesive having excellent heat resistance, Patent Document 4 discloses an adhesive containing a soluble polyester, a phenoxy resin, and an imidosiloxane oligomer. However, the adhesive disclosed in Patent Document 4 is inferior in flow characteristics, and it is difficult to achieve both filling properties and leaching prevention properties.

Curable resins such as epoxy resins that have low shrinkage and are excellent in adhesion, insulation, and chemical resistance are used in many industrial products. In particular, in electronic equipment applications, many curable resin compositions are used that can give good results in a solder reflow test for short-term heat resistance and a thermal cycle test for repeated heat resistance.

In recent years, electric control units (ECUs) for vehicles, power devices using SiC, GaN, etc. have attracted attention, but curable resin compositions used in these applications have only a short time and repeated heat resistance. In addition, heat resistance (long-term heat resistance) when continuously exposed to high temperature for a long time is required.

Patent Document 5 discloses improving the low thermal expansion property, heat resistance, and the like of a curable resin composition by using a specific imide oligomer having a phenolic hydroxyl group or an amino group at a terminal as a curing agent. . However, the curable resin composition disclosed in Patent Document 5 has a problem that the storage stability is inferior, or the cured product is inferior in long-term heat resistance, although it is excellent in heat decomposition resistance. there were.
Patent Document 6 discloses a curable resin composition using an imide oligomer curing agent having an acid anhydride structure at both ends. However, the curable resin composition disclosed in Patent Document 6 has a problem that the adhesiveness is inferior, or the cured product is inferior in long-term heat resistance and low linear expansion.

Further, for example, Patent Document 6 and Patent Document 7 described above disclose curable resin compositions containing an epoxy resin and an imide oligomer as a curing agent. However, since imide oligomers are generally hard and brittle at room temperature, the curable resin compositions disclosed in Patent Documents 6 and 7 have problems in flexibility, workability, fluidity, etc. at room temperature. there were.
As a curable resin composition with improved processability and fluidity, Patent Document 5 described above includes a curable resin composition containing a liquid epoxy resin and an imide oligomer having a specific reactive functional group. It is disclosed. However, even the curable resin composition disclosed in Patent Document 5 cannot be said to have sufficient fluidity, and when the content ratio of the liquid epoxy resin is increased in order to further improve the fluidity, heat resistance and adhesiveness are lowered. There was a problem to do.
Patent Document 8 discloses a curable resin before curing by dispersing a nitrile rubber component in a resin mixture containing an imide oligomer having a specific reactive functional group, an epoxy resin, and a bismaleimide-triazine resin. A method for improving the flexibility of the composition is disclosed. However, the method disclosed in Patent Document 8 has a problem that the heat resistance of the cured product deteriorates due to the nitrile rubber component.

JP 2006-232984 A JP 2009-167396 A JP 2008-308686 A Japanese Patent Laid-Open No. 5-306386 JP 2007-91799 A Japanese Patent Laid-Open No. 61-270852 JP-T-2004-502859 JP-A-7-224269

An object of this invention is to provide the curable resin composition which is excellent in a fluid characteristic before hardening, and is excellent in adhesiveness, heat resistance, and bending resistance after hardening. Another object of the present invention is to provide a cured product of the curable resin composition, and an adhesive, an adhesive film, a cover lay film, and a printed wiring board using the curable resin composition. To do.
Another object of the present invention is to provide a curable resin composition capable of obtaining a cured product having excellent storage stability and low linear expansion, adhesion, and long-term heat resistance. Another object of the present invention is to provide a cured product of the curable resin composition, and an adhesive and an adhesive film using the curable resin composition.
Furthermore, an object of this invention is to provide the curable resin composition which is excellent in flexibility and workability before hardening, and is excellent in adhesiveness and heat resistance after hardening. Another object of the present invention is to provide a cured product of the curable resin composition, and an adhesive and an adhesive film using the curable resin composition.

Invention 1 contains a thermosetting resin, a thermoplastic resin, and an imide oligomer, and the imide oligomer is a curable resin composition having a reactive functional group capable of reacting with the thermosetting resin.
The present invention 1 will be described in detail below.

In the curable resin composition containing a thermosetting resin, a thermoplastic resin, and an imide oligomer, the present inventors use an imide oligomer having a reactive functional group capable of reacting with a thermosetting resin as the imide oligomer. I examined that. As a result, it was found that a curable resin composition having excellent flow characteristics before curing and having excellent adhesiveness, heat resistance, and bending resistance after curing was obtained, and the present invention 1 was completed.

The curable resin composition of the present invention 1 contains a thermosetting resin.
As the thermosetting resin, an epoxy resin is preferably used.
Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, 2,2′-diallyl bisphenol A type epoxy resin, and hydrogenated bisphenol type epoxy resin. , Propylene oxide-added bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, naphthylene ether Type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, dicyclopentadiene novolak type epoxy resin, biffe Examples thereof include nil novolac type epoxy resins, naphthalene phenol novolac type epoxy resins, glycidyl amine type epoxy resins, alkyl polyol type epoxy resins, rubber-modified epoxy resins, fluorene type epoxy resins, and glycidyl ester compounds. Among them, since the viscosity is low and the processability at room temperature of the resulting curable resin composition is easy to adjust, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, resorcinol type epoxy resin, etc. Epoxy resins that are liquid at room temperature are preferred. The said epoxy resin may be used independently and 2 or more types may be used together.

The minimum with a preferable number average molecular weight of the said thermosetting resin is 90, and a preferable upper limit is 3000. When the number average molecular weight of the thermosetting resin is within this range, the resulting curable resin composition is more excellent in adhesion and heat resistance. The more preferable lower limit of the number average molecular weight of the thermosetting resin is 100, and the more preferable upper limit is 2500.
In the present specification, the “number average molecular weight” is a value determined by polystyrene conversion after measurement by gel permeation chromatography (GPC). Examples of the column used when measuring the number average molecular weight in terms of polystyrene by GPC include JAIGEL-2H-A (manufactured by Nippon Analytical Industrial Co., Ltd.).

The minimum with preferable content of the said thermosetting resin in the total 100 weight part of a thermosetting resin, a thermoplastic resin, and an imide oligomer is 10 weight part, and a preferable upper limit is 90 weight part. When the content of the thermosetting resin is 10 parts by weight or more, the resulting curable resin composition is more excellent in adhesiveness and heat resistance. When the content of the thermosetting resin is 90 parts by weight or less, the resulting curable resin composition has superior flow characteristics. The minimum with more preferable content of the said thermosetting resin is 20 weight part, and a more preferable upper limit is 80 weight part.

The curable resin composition of the present invention 1 contains a thermoplastic resin.
By using the thermoplastic resin, the curable resin composition of the first aspect of the present invention has excellent flow characteristics, is easy to achieve both filling property and leaching prevention property at the time of thermocompression bonding, and resistance after curing. Excellent flexibility.

Examples of the thermoplastic resin include phenoxy resin, polyamide, acrylic resin, and polyester. Among these, phenoxy resins and polyamides are preferable from the viewpoint of heat resistance, and phenoxy resins are more preferable from the viewpoints of leaching prevention and handleability during thermocompression bonding.

Examples of the phenoxy resin include bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, bisphenol E type phenoxy resin, bisphenol A-bisphenol F type phenoxy resin, acetophenone-biphenyl type phenoxy resin, bisphenol S type phenoxy resin, phosphorus-containing Examples include phenoxy resin, trimethylcyclohexane skeleton phenoxy resin, bisphenolfluorene skeleton phenoxy resin, and the like. Of these, bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, and bisphenol A-bisphenol F type phenoxy resin are preferred.

The minimum with a preferable weight average molecular weight of the said thermoplastic resin is 3000, and a preferable upper limit is 200,000. When the weight average molecular weight of the thermoplastic resin is within this range, the resulting curable resin composition is excellent in flow characteristics and bending resistance after curing. A more preferable lower limit of the weight average molecular weight of the thermoplastic resin is 5000, a more preferable upper limit is 150,000, and a further preferable upper limit is 100,000.
In addition, when using for the use where the level requested | required as a bending resistance is higher, the minimum with the preferable weight average molecular weight of the said thermoplastic resin is 10,000.
In the present specification, the above “weight average molecular weight” is a value determined by gel conversion chromatography (GPC) using tetrahydrofuran as a solvent and calculated in terms of polystyrene. Examples of the column used when measuring the weight average molecular weight in terms of polystyrene by GPC include JAIGEL-2H-A (manufactured by Nippon Analytical Industrial Co., Ltd.).

The minimum with preferable content of the said thermoplastic resin in 100 weight part in total of a thermosetting resin, a thermoplastic resin, and an imide oligomer is 1 weight part, and a preferable upper limit is 60 weight part. When the content of the thermoplastic resin is 1 part by weight or more, the resulting curable resin composition is superior in flow characteristics and bending resistance after curing. When the content of the thermoplastic resin is 60 parts by weight or less, the resulting curable resin composition is more excellent in adhesiveness and heat resistance. The minimum with more preferable content of the said thermosetting resin is 3 weight part, and a more preferable upper limit is 50 weight part.

The curable resin composition of the present invention 1 contains an imide oligomer.
The imide oligomer has a reactive functional group that can react with the thermosetting resin. By using an imide oligomer having a reactive functional group capable of reacting with the thermosetting resin, the curable resin composition of the present invention 1 has the effect of achieving both filling properties and anti-leaching properties during thermocompression bonding, and The adhesiveness and heat resistance after curing are excellent while maintaining the bending resistance after curing.

Although the reactive functional group which the said imide oligomer has depends on the kind of thermosetting resin to be used, when using an epoxy resin as a thermosetting resin, it is preferable that they are an acid anhydride group and / or a phenolic hydroxyl group.
The imide oligomer preferably has the reactive functional group at the ends of the main chain, and more preferably at both ends.

As a method for producing an imide oligomer having an acid anhydride group as the reactive functional group, for example, an acid dianhydride represented by the following formula (1) and a diamine represented by the following formula (2) are reacted. And the like.
Moreover, as a method for producing an imide oligomer having a phenolic hydroxyl group as the reactive functional group, for example, an acid dianhydride represented by the following formula (1) and a phenolic hydroxyl group represented by the following formula (3): Examples include a method of reacting the contained monoamine. Furthermore, after reacting the acid dianhydride represented by the following formula (1) and the diamine represented by the following formula (2), the phenolic hydroxyl group-containing monoamine represented by the following formula (3) is further reacted. The method etc. to make are also mentioned.

In the formula (1), A is a tetravalent group represented by the following formula (4-1) or the following formula (4-2).

In the formula (2), B is a divalent group represented by the following formula (5-1) or the following formula (5-2), and R ¹ to R ⁴ are each independently a hydrogen atom or 1 Valent hydrocarbon group.

In formula (3), Ar is an optionally substituted divalent aromatic group, and R ⁵ and R ⁶ are each independently a hydrogen atom or a monovalent hydrocarbon group.

In formula (4-1) and formula (4-2), * is a bond position, and in formula (4-1), Z is a bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, a bond A linear or branched divalent hydrocarbon group which may have an oxygen atom at a position, or a divalent group having an aromatic ring which may have an oxygen atom at a bonding position. The hydrogen atom of the aromatic ring in formula (4-1) and formula (4-2) may be substituted.

In formula (5-1) and formula (5-2), * is a bond position, and in formula (5-1), Y is a bond, oxygen atom, carbonyl group, sulfur atom, sulfonyl group, bond A linear or branched divalent hydrocarbon group which may have an oxygen atom at a position, or a divalent group having an aromatic ring which may have an oxygen atom at a bonding position. In the phenylene groups in the formulas (5-1) and (5-2), some or all of the hydrogen atoms may be substituted with hydroxyl groups or monovalent hydrocarbon groups.

Specific examples of the method of reacting the acid dianhydride represented by the above formula (1) and the diamine represented by the above formula (2) are shown below.
First, the diamine represented by the above formula (2) is previously dissolved in a solvent in which the amic acid oligomer obtained by the reaction is soluble (for example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, etc.), and the resulting solution An acid dianhydride represented by the above formula (1) is added to and reacted to obtain an amic acid oligomer solution. Next, the solvent is removed from the obtained amic acid oligomer solution by heating, reduced pressure, or the like, or the amic acid oligomer is recovered by reprecipitation by throwing it into a poor solvent such as water, methanol, hexane, and the like. The imidization reaction proceeds by heating at 200 ° C. or higher for 1 hour or longer. By adjusting the molar ratio between the acid dianhydride represented by the above formula (1) and the diamine represented by the above formula (2), and the imidization conditions, both have a desired number average molecular weight, An imide oligomer having an acid anhydride group as a reactive functional group at the terminal can be obtained.

Specific examples of the method of reacting the acid dianhydride represented by the above formula (1) with the phenolic hydroxyl group-containing monoamine represented by the above formula (3) are shown below.
First, the phenolic hydroxyl group-containing monoamine represented by the formula (3) is dissolved in a solvent (for example, N-methylpyrrolidone, etc.) in which the amic acid oligomer obtained by the reaction is soluble, and the above formula is added to the obtained solution. The acid dianhydride represented by (1) is added and reacted to obtain an amic acid oligomer solution. Next, the solvent is removed from the obtained amic acid oligomer solution by heating, reduced pressure, or the like, or the amic acid oligomer is recovered by reprecipitation by throwing it into a poor solvent such as water, methanol, hexane, and the like. The imidization reaction proceeds by heating at 200 ° C. or higher for 1 hour or longer. By adjusting the molar ratio between the acid dianhydride represented by the above formula (1) and the phenolic hydroxyl group-containing monoamine represented by the above formula (3) and imidization conditions, a desired number average molecular weight is obtained. It is possible to obtain an imide oligomer having a phenolic hydroxyl group as a reactive functional group at both ends.

A method in which an acid dianhydride represented by the above formula (1) and a diamine represented by the above formula (2) are reacted, and then a phenolic hydroxyl group-containing monoamine represented by the above formula (3) is further reacted. Specific examples of these are shown below.
First, the diamine represented by the above formula (2) is previously dissolved in a solvent in which the amic acid oligomer obtained by the reaction is soluble (for example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, etc.), and the resulting solution The acid dianhydride represented by the above formula (1) is added and reacted to obtain a solution of an amic acid oligomer (A) having acid anhydride groups at both ends. Next, the solvent is removed from the solution of the obtained amic acid oligomer (A) by heating, reduced pressure, or the like, or it is poured into a poor solvent such as water, methanol, hexane, etc. to cause reprecipitation, so that the amic acid oligomer (A) Is further heated at about 200 ° C. or higher for 1 hour or longer to allow the imidization reaction to proceed.
The thus obtained imide oligomer having an acid anhydride group as a reactive functional group at both ends is dissolved again in a soluble solvent (for example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, etc.) The phenolic hydroxyl group-containing monoamine represented by the above formula (3) is added and reacted to obtain a solution of the amic acid oligomer (B). The solvent is removed from the resulting solution of the amic acid oligomer (B) by heating, decompression, or the like, or it is poured into a poor solvent such as water, methanol, hexane, etc. to recover the amic acid oligomer (B). Further, the imidization reaction is advanced by heating at about 200 ° C. or higher for 1 hour or longer. The molar ratio of the acid dianhydride represented by the above formula (1), the diamine represented by the above formula (2) and the phenolic hydroxyl group-containing monoamine represented by the above formula (3), and imidation conditions By adjusting, an imide oligomer having a desired number average molecular weight and having a phenolic hydroxyl group as a reactive functional group at both ends can be obtained.

Examples of the acid dianhydride represented by the above formula (1) include pyromellitic dianhydride, 3,3′-oxydiphthalic dianhydride, 3,4′-oxydiphthalic dianhydride, 4,4 '-Oxydiphthalic dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy) diphthalic anhydride, 4,4'-bis (3,4-dicarboxylphenoxy) diphenyl ether, p-phenylenebis (Trimellitate anhydride), 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 4,4′-carbonyldiphthalate An acid dianhydride etc. are mentioned. Among these, 4,4 ′-(4,4′-isopropylidenediphenoxy) diphthalic anhydride, 3,4′-oxydiphthalic dianhydride, because of its excellent solubility, heat resistance, and availability, 4,4′-oxydiphthalic dianhydride and 4,4′-carbonyldiphthalic dianhydride are preferred.

Examples of the diamine represented by the above formula (2) include 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenyl ether, 3,4 '-Diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylenediamine, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl Sulfone, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) sulfone, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy) benzene, 1,4-bis (4-aminophen) Xyl) benzene, bis (4- (4-aminophenoxy) phenyl) methane, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 1,3-bis (2- (4-aminophenyl) -2-propyl) benzene, 1,4-bis (2- (4-aminophenyl) -2-propyl) benzene, 3,3′-diamino-4,4′-dihydroxyphenylmethane, 4,4′-diamino -3,3'-dihydroxyphenylmethane, 3,3'-diamino-4,4'-dihydroxyphenyl ether, bisaminophenylfluorene, bistoluidine fluorene, 4,4'-bis (4-aminophenoxy) biphenyl, 4 , 4'-diamino-3,3'-dihydroxyphenyl ether, 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4 - diamino-2,2'-dihydroxybiphenyl, and the like. Among them, 3,4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 1,2-phenylenediamine, 1,3-phenylene is superior because of its excellent solubility, heat resistance, and availability. Diamine, 1,4-phenylenediamine, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) sulfone, 1,3-bis (2- (4-aminophenyl) ) -2-propyl) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (2- (4-aminophenyl) -2-propyl) benzene, 3,3′-dihydroxybenzidine preferable.

Examples of the phenolic hydroxyl group-containing monoamine represented by the above formula (3) include 3-aminophenol, 4-aminophenol, 4-amino-o-cresol, 5-amino-o-cresol, 4-amino-2. , 3-xylenol, 4-amino-2,5-xylenol, 4-amino-2,6-xylenol, 4-amino-1-naphthol, 5-amino-2-naphthol, 6-amino-1-naphthol, 4 -Amino-2,6-diphenylphenol and the like. Among them, a cured product having excellent availability and storage stability and a high glass transition temperature can be obtained, so that 3-aminophenol, 4-aminophenol, 4-amino-o-cresol, 5-amino-o- Cresol is preferred.

The minimum with the preferable imidation ratio of the said imide oligomer is 70%. When the imidation ratio is 70% or more, a cured product having excellent mechanical strength at high temperatures and long-term heat resistance can be obtained. A more preferable lower limit of the imidization ratio is 75%, and a more preferable lower limit is 80%. Further, there is no particular upper limit for the imidation ratio of the imide oligomer, but the substantial upper limit is 98%.
The “imidation ratio” can be determined by Fourier transform infrared spectroscopy (FT-IR). Specifically, measurement is performed by a total reflection measurement method (ATR method) using a Fourier transform infrared spectrophotometer (for example, “UMA600” manufactured by Agilent Technologies), and is derived from a carbonyl group of an amic acid. It can be derived from the peak absorbance area around 1660 cm ^{−1 by the following} equation. The “peak absorbance area of the amic acid oligomer” in the following formula is the absorbance area of the amic acid oligomer obtained by removing the solvent by evaporation without performing the imidization step in the above-described production method.
Imidation ratio (%) = 100 × (1- (peak absorbance area after imidization) / (peak absorbance area of amic acid oligomer))

The said imide oligomer may be used independently and 2 or more types may be used together.

The preferable lower limit of the number average molecular weight of the imide oligomer is 400, and the preferable upper limit is 5000. When the number average molecular weight is within this range, the obtained cured product is superior in long-term heat resistance. The more preferable lower limit of the number average molecular weight of the imide oligomer is 500, and the more preferable upper limit is 4000.

A preferable upper limit of the softening point of the imide oligomer is 250 ° C. When the softening point of the imide oligomer is 250 ° C. or less, the obtained cured product is excellent in adhesiveness and long-term heat resistance. A more preferable upper limit of the softening point of the imide oligomer is 200 ° C.
There is no particular lower limit for the softening point of the imide oligomer, but the substantial lower limit is 60 ° C.
The softening point of the imide oligomer can be determined by the ring and ball method according to JIS K 2207.

The minimum with preferable content of the said imide oligomer in the total 100 weight part of a thermosetting resin, a thermoplastic resin, and an imide oligomer is 10 weight part, and a preferable upper limit is 90 weight part. When the content of the imide oligomer is within this range, the cured product of the resulting curable resin composition is superior in mechanical strength, adhesiveness, and long-term heat resistance at high temperatures. The minimum with more preferable content of the said imide oligomer is 20 weight part, and a more preferable upper limit is 80 weight part.

In the range which does not inhibit the objective of this invention, the curable resin composition of this invention 1 may contain another hardening | curing agent in addition to the said imide oligomer.
Examples of the other curing agents include phenolic curing agents, thiol curing agents, amine curing agents, acid anhydride curing agents, cyanate curing agents, and active ester curing agents. Of these, phenolic curing agents, acid anhydride curing agents, cyanate curing agents, and active ester curing agents are preferred.

When the curable resin composition of this invention 1 contains the said other hardening | curing agent, the preferable upper limit of the content rate of the said other hardening | curing agent in a total of 100 weight part of the said imide oligomer and said other hardening | curing agent is 70. Part by weight, more preferred upper limit is 50 parts by weight, and still more preferred upper limit is 30 parts by weight.

It is preferable that the curable resin composition of this invention 1 contains a hardening accelerator. By containing the said hardening accelerator, hardening time can be shortened and productivity can be improved.

Examples of the curing accelerator include imidazole-based curing accelerators, tertiary amine-based curing accelerators, phosphine-based curing accelerators, phosphorus-based curing accelerators, photobase generators, and sulfonium salt-based curing accelerators. . Especially, since it is excellent in storage stability, an imidazole type hardening accelerator is preferable.

The content of the curing accelerator is preferably 0.01 parts by weight and preferably 10 parts by weight with respect to 100 parts by weight of the thermosetting resin. When the content of the curing accelerator is within this range, the effect of shortening the curing time is maintained while maintaining excellent adhesiveness and the like. The minimum with more preferable content of the said hardening accelerator is 0.05 weight part, and a more preferable upper limit is 5 weight part.

The curable resin composition of the present invention 1 may contain an inorganic filler for the purpose of reducing warpage by reducing the linear expansion coefficient after curing, improving adhesion reliability, and the like. Moreover, the said inorganic filler can be used suitably also as a flow regulator.

Examples of the inorganic filler include silica such as fumed silica and colloidal silica, alumina, aluminum nitride, boron nitride, silicon nitride, glass powder, glass frit, glass fiber, carbon fiber, inorganic ion exchanger, and the like. .

The content of the inorganic filler is preferably 500 parts by weight with respect to 100 parts by weight of the thermosetting resin. When the content of the inorganic filler is 500 parts by weight or less, the adhesive reliability is improved or the flow is adjusted while maintaining excellent processability and the like. The upper limit with more preferable content of the said inorganic filler is 400 weight part.

The curable resin composition of the present invention 1 may contain an organic filler for the purpose of relaxing stress, imparting toughness, and the like.

Examples of the organic filler include silicone rubber particles, acrylic rubber particles, urethane rubber particles, polyamide particles, polyamideimide particles, polyimide particles, benzoguanamine particles, and core-shell particles thereof. Of these, polyamide particles, polyamideimide particles, and polyimide particles are preferable.

The content of the organic filler is preferably 500 parts by weight with respect to 100 parts by weight of the thermosetting resin. When the content of the organic filler is 500 parts by weight or less, the obtained cured product is excellent in toughness and the like while maintaining excellent adhesiveness and the like. The upper limit with more preferable content of the said organic filler is 400 weight part.

The curable resin composition of the present invention 1 may contain a reactive diluent as long as the object of the present invention is not impaired.
As the reactive diluent, a reactive diluent having two or more reactive functional groups in one molecule is preferable from the viewpoint of adhesion reliability.
As a reactive functional group which the said reactive diluent has, the thing similar to the reactive functional group which the high molecular compound mentioned above has is mentioned.

The curable resin composition of the present invention 1 may further contain additives such as a solvent, a coupling agent, a dispersant, a storage stabilizer, a bleed inhibitor, and a flux agent.

As a method for producing the curable resin composition of the present invention 1, for example, using a mixer such as a homodisper, a universal mixer, a Banbury mixer, a kneader, a thermosetting resin, a thermoplastic resin, and a curing agent And other curing agents, curing accelerators, inorganic fillers (flow control agents) and the like that are added as necessary.

The minimum with the minimum melt viscosity of the curable resin composition of this invention 1 is 5 kPa * s, and a preferable upper limit is 300 kPa * s. When the minimum melt viscosity is within this range, the curable resin composition of the present invention 1 has more excellent flow characteristics. A more preferable lower limit of the minimum melt viscosity is 10 kPa · s, a more preferable upper limit is 200 kPa · s, and a still more preferable upper limit is 150 kPa · s.
The minimum melt viscosity is measured using a rotary rheometer (for example, “VAR-100” manufactured by Rheology Corporation) under the conditions of a heating rate of 10 ° C./min, a frequency of 1 Hz, and a strain of 1%. It can be determined from the lowest value of the complex viscosity when measured from a temperature range of 60 ° C to 300 ° C.

Although the curable resin composition of the present invention 1 can be used for a wide range of applications, it can be suitably used for an electronic material application that requires particularly high heat resistance. For example, it can be used for die attach agents in aviation, in-vehicle electric control unit (ECU) applications, power device applications using SiC, and GaN. Also, for example, adhesives for power overlay packages, adhesives for printed wiring boards, adhesives for cover lay films of flexible printed wiring boards, copper-clad laminates, adhesives for semiconductor bonding, interlayer insulating films, prepregs, and LED sealing It can also be used for a stopper, an adhesive for structural materials, and the like. Especially, it is used suitably for an adhesive agent use, and it is used especially suitably for the adhesive agent for cover-lay films of a flexible printed wiring board.
An adhesive comprising the curable resin composition of the present invention 1 (hereinafter also referred to as “adhesive of the present invention 1”) is also one aspect of the present invention. The adhesive of the present invention 1 can form an adhesive film (curable resin composition film) by a method such as drying after coating on a release film, and by curing the adhesive film. A cured product can be obtained. The cured product of the curable resin composition of the present invention 1 is also one aspect of the present invention.
An adhesive film using the adhesive of the present invention 1 is also one aspect of the present invention.
Further, a cover lay film (hereinafter also referred to as “cover lay film of the present invention 1”) having an adhesive layer made of a cured product of the curable resin composition of the present invention 1 and an insulating film is also 1 of the present invention. One. Furthermore, the flexible printed wiring board which has the coverlay film of this invention 1 is also one of this invention.

The present invention 2 is a curable resin composition containing a curable resin, an imide oligomer, and a curing accelerator, and the imide oligomer is a curable resin composition represented by the following formula (6).

In the formula (6), X is a tetravalent group represented by the following formula (7-1), (7-2), or (7-3), and Y is a formula (8-1) ), (8-2), (8-3), or (8-4).

In the formulas (7-1) to (7-3), * is a bonding position. The hydrogen atom of the aromatic ring in formulas (7-1) to (7-3) may be substituted.

In formulas (8-1) and (8-2), Z represents a bond, an oxygen atom, a sulfonyl group, or a linear or branched divalent carbon atom which may have an oxygen atom at the bonding position. It is a hydrogen group or a divalent group having an aromatic ring which may have an oxygen atom at the bonding position. The hydrogen atom of the aromatic ring in formulas (8-1) and (8-2) may be substituted. In formulas (8-3) and (8-4), R ⁷ to R ¹⁴ each represents a hydrogen atom or a monovalent hydrocarbon group, and may be the same or different. In formulas (8-1) to (8-4), * represents a bonding position.
The present invention 2 will be described in detail below.

In the curable resin composition containing a curable resin, an imide oligomer, and a curing accelerator, the present inventors have excellent storage stability by using the imide oligomer having a specific structure, and The inventors found that a cured product excellent in low linear expansion property, adhesiveness, and long-term heat resistance can be obtained, and completed the present invention 2.

The curable resin composition of the present invention 2 contains an imide oligomer.
The imide oligomer is represented by the above formula (6). Hereinafter, the imide oligomer represented by the above formula (6) is also referred to as an imide oligomer according to the present invention 2. By containing the imide oligomer according to the present invention 2, the curable resin composition of the present invention 2 is a cured product having excellent storage stability and low linear expansion, adhesion, and long-term heat resistance. It can be obtained.

The minimum with a preferable number average molecular weight of the imide oligomer concerning this invention 2 is 400, and a preferable upper limit is 5000. When the number average molecular weight is within this range, the obtained cured product is excellent in adhesiveness and long-term heat resistance. The more preferable lower limit of the number average molecular weight of the imide oligomer according to the present invention 2 is 500, and the more preferable upper limit is 4000.
In the present specification, the “number average molecular weight” is a value determined by polystyrene conversion after measurement by gel permeation chromatography (GPC). Examples of the column used when measuring the number average molecular weight in terms of polystyrene by GPC include JAIGEL-2H-A (manufactured by Nippon Analytical Industrial Co., Ltd.).

The upper limit with the softening point of the imide oligomer concerning this invention 2 is 250 degreeC. When the softening point of the imide oligomer according to the second aspect of the invention is 250 ° C. or less, the obtained cured product is excellent in adhesiveness and long-term heat resistance. The upper limit with a more preferable softening point of the imide oligomer concerning this invention 2 is 200 degreeC.
There is no particular lower limit for the softening point of the imide oligomer according to the present invention 2, but the substantial lower limit is 60 ° C.
The softening point can be determined by the ring and ball method according to JIS K 2207.

Examples of the method for producing the imide oligomer according to the present invention 2 include a method of reacting an acid dianhydride represented by the following formula (9) and a diamine represented by the following formula (10).

In formula (9), X is the same tetravalent group as X in formula (6).

In formula (10), Y is the same divalent group as Y in formula (6), and R ¹⁵ to R ¹⁸ are each independently a hydrogen atom or a monovalent hydrocarbon group.

Specific examples of the method of reacting the acid dianhydride represented by the above formula (9) and the diamine represented by the above formula (10) are shown below.
First, the diamine represented by the above formula (10) is previously dissolved in a solvent in which the amic acid oligomer obtained by the reaction is soluble (for example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, etc.), and the resulting solution The acid dianhydride represented by the above formula (9) is added to and reacted to obtain an amic acid oligomer solution. Next, the solvent is removed from the obtained amic acid oligomer solution by heating, reduced pressure, or the like, or the amic acid oligomer is recovered by reprecipitation by throwing it into a poor solvent such as water, methanol, hexane, and the like. The imidization reaction proceeds by heating at 200 ° C. or higher for 1 hour or longer. By adjusting the molar ratio of the acid dianhydride represented by the above formula (9) and the diamine represented by the above formula (10) and the imidization conditions, it is represented by the above formula (6) and desired. An imide oligomer having a number average molecular weight of

Specific examples of the acid dianhydride represented by the above formula (9) include 3,4′-oxydiphthalic dianhydride, 4,4′-oxydiphthalic dianhydride, 4,4 ′-(4 , 4'-isopropylidenediphenoxy) diphthalic anhydride can be used.

Examples of the diamine represented by the above formula (10) include 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 1,3 -Phenylenediamine, 1,4-phenylenediamine, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4- Aminophenoxy) phenyl) sulfone, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, bis (4- (4-Aminophenoxy) phenyl) methane, 2,2-bis (4- (4-amino) Enoxy) phenyl) propane, 1,3-bis (2- (4-aminophenyl) -2-propyl) benzene, 1,4-bis (2- (4-aminophenyl) -2-propyl) benzene, bisamino Examples thereof include phenylfluorene, 4,4′-bis (4-aminophenoxy) biphenyl, diethyltoluenediamine and the like. Among them, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (1, because of excellent solubility, heat resistance and availability. 4-aminophenoxy) benzene, 1,3-phenylenediamine, 1,4-phenylenediamine, 3,3′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfone, bis (4- (3-aminophenoxy) phenyl ) Sulfone, bis (4- (4-aminophenoxy) phenyl) sulfone, diethyltoluenediamine, 3,3′-diaminodiphenylmethane, and 4,4′-diaminodiphenylmethane are preferred. In addition, 1,3-bis (4-aminophenoxy) benzene is particularly preferred because of its excellent low linear expansion.

The minimum with the preferable imidation ratio of the imide oligomer concerning this invention 2 is 70%. When the imidation ratio is 70% or more, a cured product having excellent mechanical strength at high temperatures and long-term heat resistance can be obtained. A more preferable lower limit of the imidization ratio is 75%, and a more preferable lower limit is 80%. Moreover, although there is no preferable upper limit in particular of the imidation ratio of the imide oligomer concerning this invention 2, a substantial upper limit is 98%.
The “imidation ratio” can be determined by Fourier transform infrared spectroscopy (FT-IR). Specifically, measurement is performed by a total reflection measurement method (ATR method) using a Fourier transform infrared spectrophotometer (for example, “UMA600” manufactured by Agilent Technologies), and is derived from a carbonyl group of an amic acid. It can be derived from the peak absorbance area around 1660 cm ^{−1 by the following} equation. In addition, the “peak absorbance area of the amic acid oligomer” in the following formula is obtained by reacting the acid dianhydride represented by the above formula (9) with the diamine represented by the above formula (10), and then imidizing. This is the absorbance area of the amic acid oligomer obtained by removing the solvent by evaporation without performing the step.
Imidation ratio (%) = 100 × (1- (peak absorbance area after imidization) / (peak absorbance area of amic acid oligomer))

The minimum with preferable content of the imide oligomer concerning this invention 2 in a total of 100 weight part of curable resin, an imide oligomer, and a hardening accelerator is 20 weight part, and a preferable upper limit is 90 weight part. When the content of the imide oligomer according to the present invention 2 is within this range, the resulting cured product of the curable resin composition is superior in mechanical strength at high temperature, adhesiveness, and long-term heat resistance. The minimum with more preferable content of the imide oligomer concerning this invention 2 is 30 weight part, and a more preferable upper limit is 80 weight part.

The curable resin composition of the present invention 2 may contain other imide oligomers and other curing agents in addition to the imide oligomer according to the present invention 2 as long as the object of the present invention is not impaired.
As said other imide oligomer, the imide oligomer etc. which have an imide group and a reactive functional group in a molecule | numerator other than the imide oligomer concerning this invention 2 are mentioned, for example.
Examples of the other curing agents include phenolic curing agents, thiol curing agents, amine curing agents, acid anhydride curing agents, cyanate curing agents, and active ester curing agents. Of these, phenolic curing agents, acid anhydride curing agents, cyanate curing agents, and active ester curing agents are preferred.

When the curable resin composition of this invention 2 contains the said other imide oligomer or the said other hardening | curing agent, the preferable upper limit of the content rate of the said other imide oligomer or the said other hardening | curing agent in the whole hardening | curing agent is 70. The upper limit is 50% by weight, and a more preferable upper limit is 30% by weight.

The curable resin composition of the present invention 2 contains a curable resin.
An epoxy resin is preferably used as the curable resin.
Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, 2,2′-diallyl bisphenol A type epoxy resin, and hydrogenated bisphenol type epoxy resin. , Propylene oxide-added bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, naphthylene ether Type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, dicyclopentadiene novolak type epoxy resin, biffe Examples thereof include nil novolac type epoxy resins, naphthalene phenol novolac type epoxy resins, glycidyl amine type epoxy resins, alkyl polyol type epoxy resins, rubber-modified epoxy resins, fluorene type epoxy resins, and glycidyl ester compounds. Among them, since the viscosity is low and the processability at room temperature of the resulting curable resin composition is easy to adjust, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, resorcinol type epoxy resin, etc. Epoxy resins that are liquid at room temperature are preferred. The said epoxy resin may be used independently and 2 or more types may be used together.

The curable resin composition of the present invention 2 contains a curing accelerator. By containing the curing accelerator, not only the curing time can be shortened and the productivity can be improved, but also the long-term heat resistance of the cured product can be improved.

The curing accelerator is preferably a basic catalyst. For example, a curing accelerator having an imidazole skeleton (imidazole curing accelerator), a tertiary amine curing accelerator, a phosphorus curing accelerator, a photobase generator. Etc. Among these, a curing accelerator having an imidazole skeleton is more preferable because of excellent storage stability.
Examples of the curing accelerator having an imidazole skeleton include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4- Methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole 1-cyanoethyl-2-phenylimidazole, 2,4-diamino-6- (2′-methylimidazolyl- (1 ′))-ethyl-s-triazine, 2,4-diamino-6- (2′-un Decylimidazolyl- (1 ′))-ethyl-s-triazine, 2 , 4-Diamino-6- (2'-ethyl-4'-methylimidazolyl- (1 '))-ethyl-s-triazine, 2,4-diamino-6- (2'-methylimidazolyl- (1') ) -Ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl- And 5-hydroxymethylimidazole.

Examples of the curing accelerator other than the curing accelerator having the imidazole skeleton include a tertiary amine-based curing accelerator, a phosphine-based curing accelerator, a photobase generator, and a sulfonium salt-based curing accelerator.

The minimum with preferable content of the said hardening accelerator in 100 weight part in total of curable resin, an imide oligomer, and a hardening accelerator is 0.8 weight part, and a preferable upper limit is 10 weight part. When the content of the curing accelerator is 0.8 parts by weight or more, the resulting curable resin composition is more excellent in the adhesiveness and long-term heat resistance of the cured product. When the content of the curing accelerator is 10 parts by weight or less, the resulting curable resin composition is more excellent in storage stability. A more preferable lower limit of the content of the curing accelerator is 1 part by weight, and a more preferable upper limit is 9 parts by weight.

The curable resin composition of the present invention 2 may contain an inorganic filler for the purpose of reducing warpage by reducing the linear expansion coefficient after curing, improving adhesion reliability, or the like. Moreover, the said inorganic filler can be used suitably also as a flow regulator.

The content of the inorganic filler is preferably 300 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the inorganic filler is 300 parts by weight or less, the adhesive reliability is improved or the flow is adjusted while maintaining excellent processability and the like. The upper limit with more preferable content of the said inorganic filler is 200 weight part.

The curable resin composition of the present invention 2 may contain an organic filler for the purpose of stress relaxation, imparting toughness and the like.

The upper limit of the content of the organic filler is preferably 300 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the organic filler is 300 parts by weight or less, the obtained cured product is excellent in toughness and the like while maintaining excellent adhesiveness and the like. The upper limit with more preferable content of the said organic filler is 200 weight part.

The curable resin composition of the present invention 2 may contain a polymer compound as long as the object of the present invention is not impaired. The polymer compound serves as a film forming component.

The polymer compound may have a reactive functional group.
Examples of the reactive functional group include an amino group, a urethane group, an imide group, a hydroxyl group, a carboxyl group, and an epoxy group.

The curable resin composition of the present invention 2 may contain a reactive diluent as long as the object of the present invention is not impaired.
As the reactive diluent, a reactive diluent having two or more reactive functional groups in one molecule is preferable from the viewpoint of adhesion reliability.
As a reactive functional group which the said reactive diluent has, the thing similar to the reactive functional group which the high molecular compound mentioned above has is mentioned.

The curable resin composition of the present invention 2 may further contain additives such as a solvent, a coupling agent, a dispersant, a storage stabilizer, a bleed inhibitor, a flux agent, a leveling agent, and a flame retardant.

As a method for producing the curable resin composition of the present invention 2, for example, using a mixer such as a homodisper, a universal mixer, a Banbury mixer, a kneader, the curable resin and the imide oligomer according to the present invention 2, Examples thereof include a method of mixing a curing accelerator with other curing agents and inorganic fillers (flow modifiers) added as necessary.
Moreover, the film which consists of curable resin composition of this invention 2 can be obtained by apply | coating the curable resin composition of this invention 2 on a film, and making it dry, this curable resin composition film can be obtained. A cured product can be obtained by curing. A cured product of the curable resin composition of the present invention 2 (hereinafter also referred to as “cured product of the present invention 2”) is also one aspect of the present invention.

In the cured product of Invention 2, the average linear expansion coefficient in the temperature range of 40 ° C. to 80 ° C. is preferably 60 ppm or less, and more preferably 55 ppm or less, from the viewpoint of reducing warpage or improving the adhesion reliability. The average linear expansion coefficient is preferably as small as possible.
The average linear expansion coefficient can be measured for a cured product having a thickness of about 400 μm using a thermomechanical analyzer. Specifically, after heating the cured product having a sample length of 1 cm from 0 ° C. to 300 ° C. under the conditions of a load of 5 g and a temperature increase rate of 10 ° C./min, it is once cooled and then again from 0 ° C. to 300 ° C. The average linear expansion coefficient in the temperature range from 40 ° C. to 80 ° C. can be determined based on the temperature and dimensional change data obtained in the second measurement after the temperature is raised.
The cured product for measuring the average linear expansion coefficient can be obtained by heating the curable resin composition film at 190 ° C. for 30 minutes or more.
Examples of the thermomechanical analyzer include TMA / SS-6000 (manufactured by Hitachi High-Tech Science Co., Ltd.).

Although the curable resin composition of the present invention 2 can be used for a wide range of applications, it can be suitably used for an electronic material application that requires particularly high heat resistance. For example, it can be used for die attach agents in aviation, in-vehicle electric control unit (ECU) applications, power device applications using SiC, and GaN. Also, for example, power overlay package adhesive, printed wiring board adhesive, flexible printed circuit board coverlay adhesive, copper-clad laminate, semiconductor bonding adhesive, interlayer insulation film, prepreg, LED sealing It can also be used for adhesives and adhesives for structural materials. Especially, it is used suitably for an adhesive agent use.
The adhesive agent which consists of curable resin composition of this invention 2 is also one of this invention. Moreover, the adhesive film using the curable resin composition of this invention 2 is also one of this invention.

Invention 3 is a curable resin composition containing a curable resin and an imide oligomer, and the curable resin is liquid at 25 ° C., and the imide oligomer is dispersed in solid particles at 25 ° C. The curable resin composition.
The present invention 3 will be described in detail below.

In the curable resin composition containing a curable resin and an imide oligomer, the present inventors use a liquid resin at 25 ° C. as the curable resin, and form the imide oligomer into solid particles at 25 ° C. We considered to disperse. As a result, it was found that a curable resin composition excellent in flexibility and workability before curing and excellent in adhesiveness and heat resistance after curing could be obtained, and the present invention 3 was completed.

The curable resin composition of the present invention 3 contains a curable resin.
The curable resin is liquid at 25 ° C. When the curable resin is liquid at 25 ° C., the curable resin composition of the present invention 3 is excellent in fluidity and workability. Moreover, in order to disperse the imide oligomer described later in the form of solid particles, as the curable resin, one in which the imide oligomer is insoluble at 25 ° C. is used.

An epoxy resin is preferably used as the curable resin.
Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, 2,2′-diallyl bisphenol A type epoxy resin, and hydrogenated bisphenol type epoxy resin. , Propylene oxide-added bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, naphthylene ether Type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, dicyclopentadiene novolak type epoxy resin, biffe Examples thereof include nil novolac type epoxy resins, naphthalene phenol novolac type epoxy resins, glycidyl amine type epoxy resins, alkyl polyol type epoxy resins, rubber-modified epoxy resins, fluorene type epoxy resins, and glycidyl ester compounds. Among them, since the viscosity is low and the processability at room temperature of the resulting curable resin composition is easy to adjust, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, resorcinol type epoxy resin, etc. Epoxy resins that are liquid at room temperature are preferred. The said epoxy resin may be used independently and 2 or more types may be used together.

The curable resin composition of the present invention 3 contains an imide oligomer. In the curable resin composition of the present invention 3, the imide oligomer is dispersed in solid particles at 25 ° C. When the imide oligomer is dispersed in the form of solid particles, the curable resin composition of the present invention 3 is excellent in flexibility while maintaining excellent fluidity and workability, and has adhesiveness and heat resistance. It becomes what can obtain the hardened | cured material which is excellent in.
The term “dispersed in the form of solid particles” means that the particles are present without being dissolved, and that most of the particles are aggregated and dispersed without being unevenly distributed. This can be confirmed by direct observation using a microscope or an electron microscope.

The imide oligomer preferably has a reactive functional group that can react with the curable resin.
Although the said reactive functional group is based also on the kind of curable resin to be used, when using an epoxy resin as curable resin, it is preferable that they are an acid anhydride group and / or a phenolic hydroxyl group.
The imide oligomer preferably has the reactive functional group at the ends of the main chain, and more preferably at both ends.

As a method for producing an imide oligomer having an acid anhydride group as the reactive functional group, for example, an acid dianhydride represented by the following formula (11) and a diamine represented by the following formula (12) are reacted. And the like.
Moreover, as a method of manufacturing the imide oligomer which has a phenolic hydroxyl group as said reactive functional group, the following methods etc. are mentioned, for example.
That is, a method of reacting an acid dianhydride represented by the following formula (11) with a phenolic hydroxyl group-containing monoamine represented by the following formula (13), or an acid dianhydride represented by the following formula (11) And a diamine represented by the following formula (12), and a method of reacting a phenolic hydroxyl group-containing monoamine represented by the following formula (13).

In the formula (11), A is a tetravalent group represented by the following formula (14-1) or the following formula (14-2).

In the formula (12), B is a divalent group represented by the following formula (15-1) or the following formula (15-2), and R ¹⁹ to R ²² are each independently a hydrogen atom or 1 Valent hydrocarbon group.

In formula (13), Ar is an optionally substituted divalent aromatic group, and R ²³ and R ²⁴ are each independently a hydrogen atom or a monovalent hydrocarbon group.

In formula (14-1) and formula (14-2), * represents a bonding position, and in formula (14-1), Z represents a bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, a bond A linear or branched divalent hydrocarbon group which may have an oxygen atom at a position, or a divalent group having an aromatic ring which may have an oxygen atom at a bonding position. The hydrogen atom of the aromatic ring in formula (14-1) and formula (14-2) may be substituted.

In formula (15-1) and formula (15-2), * represents a bonding position, and in formula (15-1), Y represents a bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, a bond A linear or branched divalent hydrocarbon group which may have an oxygen atom at a position, or a divalent group having an aromatic ring which may have an oxygen atom at a bonding position. In the phenylene groups in the formulas (15-1) and (15-2), some or all of the hydrogen atoms may be substituted with hydroxyl groups or monovalent hydrocarbon groups.

Specific examples of the method of reacting the acid dianhydride represented by the above formula (11) and the diamine represented by the above formula (12) are shown below.
First, the diamine represented by the above formula (12) is previously dissolved in a solvent in which the amic acid oligomer obtained by the reaction is soluble (for example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, etc.), and the resulting solution The acid dianhydride represented by the above formula (11) is added and reacted to obtain an amic acid oligomer solution. Next, the solvent is removed from the obtained amic acid oligomer solution by heating, reduced pressure, or the like, or the amic acid oligomer is recovered by reprecipitation by throwing it into a poor solvent such as water, methanol, hexane, and the like. The imidization reaction proceeds by heating at 200 ° C. or higher for 1 hour or longer. By adjusting the molar ratio of the acid dianhydride represented by the above formula (11) and the diamine represented by the above formula (12) and the imidization conditions, the desired number average molecular weight is obtained. An imide oligomer having an acid anhydride group as a reactive functional group at the terminal can be obtained.

Specific examples of the method of reacting the acid dianhydride represented by the above formula (11) with the phenolic hydroxyl group-containing monoamine represented by the above formula (13) are shown below.
First, the phenolic hydroxyl group-containing monoamine represented by the formula (13) is dissolved in a solvent (for example, N-methylpyrrolidone etc.) in which the amic acid oligomer obtained by the reaction is soluble, and the above formula is added to the obtained solution. The acid dianhydride represented by (11) is added and reacted to obtain an amic acid oligomer solution. Next, the solvent is removed from the obtained amic acid oligomer solution by heating, reduced pressure, or the like, or the amic acid oligomer is recovered by reprecipitation by throwing it into a poor solvent such as water, methanol, hexane, and the like. The imidization reaction proceeds by heating at 200 ° C. or higher for 1 hour or longer. By adjusting the molar ratio between the acid dianhydride represented by the above formula (11) and the phenolic hydroxyl group-containing monoamine represented by the above formula (13) and imidization conditions, a desired number average molecular weight is obtained. It is possible to obtain an imide oligomer having a phenolic hydroxyl group as a reactive functional group at both ends.

A method of reacting a phenolic hydroxyl group-containing monoamine represented by the above formula (13) after reacting the acid dianhydride represented by the above formula (11) with the diamine represented by the above formula (12). Specific examples of these are shown below.
First, the diamine represented by the above formula (12) is previously dissolved in a solvent in which the amic acid oligomer obtained by the reaction is soluble (for example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, etc.), and the resulting solution The acid dianhydride represented by the above formula (11) is added and reacted to obtain a solution of an amic acid oligomer (A) having an acid anhydride group at both ends. Next, the solvent is removed from the solution of the obtained amic acid oligomer (A) by heating, reduced pressure, or the like, or it is poured into a poor solvent such as water, methanol, hexane, etc. to cause reprecipitation, so that the amic acid oligomer (A) Is further heated at about 200 ° C. or higher for 1 hour or longer to allow the imidization reaction to proceed.
The thus obtained imide oligomer having an acid anhydride group as a reactive functional group at both ends is dissolved again in a soluble solvent (for example, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, etc.) A phenolic hydroxyl group-containing monoamine represented by the above formula (13) is added and reacted to obtain a solution of the amic acid oligomer (B). The solvent is removed from the resulting solution of the amic acid oligomer (B) by heating, decompression, or the like, or it is poured into a poor solvent such as water, methanol, hexane, etc. to recover the amic acid oligomer (B). Further, the imidization reaction is advanced by heating at about 200 ° C. or higher for 1 hour or longer. The molar ratio of the acid dianhydride represented by the above formula (11), the diamine represented by the above formula (12) and the phenolic hydroxyl group-containing monoamine represented by the above formula (13), and imidation conditions By adjusting, an imide oligomer having a desired number average molecular weight and having a phenolic hydroxyl group as a reactive functional group at both ends can be obtained.

Examples of the acid dianhydride represented by the above formula (11) include pyromellitic dianhydride, 3,3′-oxydiphthalic dianhydride, 3,4′-oxydiphthalic dianhydride, 4,4 '-Oxydiphthalic dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy) diphthalic anhydride, 4,4'-bis (3,4-dicarboxylphenoxy) diphenyl ether, p-phenylenebis (Trimellitate anhydride), 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 4,4′-carbonyldiphthalate An acid dianhydride etc. are mentioned. Among them, 4,4 ′-(4,4′-isopropylidenediphenoxy) diphthalic anhydride, 3,4, because of its excellent softening point and solubility control, heat resistance, and availability of imide oligomers. '-Oxydiphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, and 4,4'-carbonyldiphthalic dianhydride are preferred.

Examples of the diamine represented by the above formula (12) include 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenyl ether, 3,4 '-Diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylenediamine, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl Sulfone, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) sulfone, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy) benzene, 1,4-bis (4-aminophenyl) Noxy) benzene, bis (4- (4-aminophenoxy) phenyl) methane, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 1,3-bis (2- (4-aminophenyl) -2-propyl) benzene, 1,4-bis (2- (4-aminophenyl) -2-propyl) benzene, 3,3′-diamino-4,4′-dihydroxyphenylmethane, 4,4′-diamino -3,3'-dihydroxyphenylmethane, 3,3'-diamino-4,4'-dihydroxyphenyl ether, bisaminophenylfluorene, bistoluidine fluorene, 4,4'-bis (4-aminophenoxy) biphenyl, 4 , 4′-diamino-3,3′-dihydroxyphenyl ether, 3,3′-diamino-4,4′-dihydroxybiphenyl, 4, '- diamino-2,2'-dihydroxybiphenyl, and the like. Among them, imide oligomers are excellent in softening point and solubility control, heat resistance, and availability, and therefore, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 1,2-phenylenediamine, 1 , 3-phenylenediamine, 1,4-phenylenediamine, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) sulfone, 1,3-bis (2- ( 4-aminophenyl) -2-propyl) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (2- (4-aminophenyl) -2-propyl) benzene, 3,3 ′ -Dihydroxybenzidine is preferred.

Examples of the phenolic hydroxyl group-containing monoamine represented by the above formula (13) include 3-aminophenol, 4-aminophenol, 4-amino-o-cresol, 5-amino-o-cresol, and 4-amino-2. , 3-xylenol, 4-amino-2,5-xylenol, 4-amino-2,6-xylenol, 4-amino-1-naphthol, 5-amino-2-naphthol, 6-amino-1-naphthol, 4 -Amino-2,6-diphenylphenol and the like. Among them, a cured product having excellent availability and storage stability and a high glass transition temperature can be obtained, so that 3-aminophenol, 4-aminophenol, 4-amino-o-cresol, 5-amino-o- Cresol is preferred.

The minimum with the preferable imidation ratio of the said imide oligomer is 70%. When the imidation ratio is 70% or more, a cured product having excellent mechanical strength at high temperatures and long-term heat resistance can be obtained. A more preferable lower limit of the imidization ratio is 75%, and a more preferable lower limit is 80%. Further, there is no particular upper limit for the imidation ratio of the imide oligomer, but the substantial upper limit is 98%.
The “imidation ratio” can be determined by Fourier transform infrared spectroscopy (FT-IR). Specifically, measurement is performed by a total reflection measurement method (ATR method) using a Fourier transform infrared spectrophotometer (for example, “UMA600” manufactured by Agilent Technologies), and is derived from a carbonyl group of an amic acid. It can be derived from the peak absorbance area around 1660 cm ^{−1 by the following} equation. The “peak absorbance area of the amic acid oligomer” in the following formula is determined by reacting the acid dianhydride represented by the formula (11) with each amine compound, and then performing the imidization step without performing the solvent. It is the absorbance area of the amic acid oligomer obtained by removing. The solvent can be removed by evaporation.
Imidation ratio (%) = 100 × (1- (peak absorbance area after imidization) / (peak absorbance area of amic acid oligomer))

The minimum with a preferable average particle diameter of the said imide oligomer in the curable resin composition of this invention 3 is 0.5 micrometer, and a preferable upper limit is 20 micrometers. When the average particle diameter of the imide oligomer is 0.5 μm or more, the resulting curable resin composition is excellent in flexibility and workability in a state before curing. When the average particle diameter of the imide oligomer is 20 μm or less, the resulting curable resin composition is excellent in uniformity, and a cured product excellent in adhesiveness and heat resistance is obtained. The minimum with a more preferable average particle diameter of the said imide oligomer is 1 micrometer, and a more preferable upper limit is 10 micrometers.

The preferable lower limit of the number average molecular weight of the imide oligomer is 400, and the preferable upper limit is 5000. When the number average molecular weight is within this range, the obtained cured product is superior in long-term heat resistance. The more preferable lower limit of the number average molecular weight of the imide oligomer is 500, and the more preferable upper limit is 4000.
In the present specification, the “number average molecular weight” is a value determined by polystyrene conversion after measurement by gel permeation chromatography (GPC). Examples of the column used when measuring the number average molecular weight in terms of polystyrene by GPC include JAIGEL-2H-A (manufactured by Nippon Analytical Industrial Co., Ltd.).

The upper limit with preferable melting | fusing point of the said imide oligomer is 300 degreeC. When the melting point of the imide oligomer is 300 ° C. or lower, the resulting curable resin composition is superior in adhesion and long-term heat resistance. A more preferable upper limit of the melting point of the imide oligomer is 250 ° C.
The melting point of the imide oligomer can be determined by differential scanning calorimetry or a commercially available melting point measuring device.

A preferable lower limit of the content of the imide oligomer is 30 parts by weight and a preferable upper limit is 500 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the imide oligomer is within this range, the cured product of the resulting curable resin composition is superior in mechanical strength, adhesiveness, and long-term heat resistance at high temperatures. The minimum with more preferable content of the said imide oligomer is 50 weight part, and a more preferable upper limit is 400 weight part.

The curable resin composition of the present invention 3 may contain only the imide oligomer that is insoluble in the curable resin composition at 25 ° C as the imide oligomer, or insoluble in the curable resin composition at 25 ° C. You may contain a certain imide oligomer and the imide oligomer which can melt | dissolve in curable resin composition at 25 degreeC. Hereinafter, an imide oligomer that is insoluble in the curable resin composition at 25 ° C. is also referred to as an “insoluble imide oligomer”, and an imide oligomer that can be dissolved in the curable resin composition at 25 ° C. is also referred to as a “soluble imide oligomer”. . That is, in the curable resin composition of the present invention 3, a part of the imide oligomer (soluble imide oligomer) may be dissolved and a part (insoluble imide oligomer) may be dispersed in solid particles. In such a case, strong adhesive force is expressed by the wettability by the soluble imide oligomer, and fluidity, workability, and flexibility can be imparted by the insoluble imide oligomer.
The above-mentioned “insoluble in the curable resin composition” means insoluble in the curable resin when a solvent described later is not used, and the solvent and the curing when a solvent described later is used. It is insoluble in the conductive resin. Further, the above-mentioned “can be dissolved in the curable resin composition” means that it can be dissolved in the curable resin when a solvent described later is not used, and when the solvent described later is used, the solvent and the curing are used. It can be dissolved in a functional resin.

When using the said soluble imide oligomer, it is preferable that the content rate of the said soluble imide oligomer is 80 weight part or less in 100 weight part of the whole imide oligomer. When the content ratio of the soluble imide oligomer is 80 parts by weight or less, the obtained curable resin composition is excellent in adhesiveness while maintaining excellent flexibility.
Moreover, when using the said soluble imide oligomer, it is preferable that the content rate of the said soluble imide oligomer is 20 weight part or more.

The curable resin composition of the present invention 3 may contain another curing agent in addition to the imide oligomer as long as the object of the present invention is not impaired.
Examples of the other curing agents include phenolic curing agents, thiol curing agents, amine curing agents, acid anhydride curing agents, cyanate curing agents, and active ester curing agents. Of these, phenolic curing agents, acid anhydride curing agents, cyanate curing agents, and active ester curing agents are preferred.

When the curable resin composition of this invention 3 contains the said other hardening | curing agent, the preferable upper limit of the content rate of the said other hardening | curing agent in a total of 100 weight part of the said imide oligomer and said other hardening | curing agent is 70. Part by weight, more preferred upper limit is 50 parts by weight, and still more preferred upper limit is 30 parts by weight.

It is preferable that the curable resin composition of this invention 3 contains a hardening accelerator. By containing the said hardening accelerator, hardening time can be shortened and productivity can be improved.

The content of the curing accelerator is preferably 0.01 parts by weight and preferably 10 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the curing accelerator is within this range, the effect of shortening the curing time is maintained while maintaining excellent adhesiveness and the like. The minimum with more preferable content of the said hardening accelerator is 0.05 weight part, and a more preferable upper limit is 5 weight part.

The curable resin composition of the present invention 3 may contain an inorganic filler for the purpose of reducing warpage by reducing the coefficient of linear expansion after curing, improving adhesion reliability, and the like. Moreover, the said inorganic filler can be used suitably also as a flow regulator.

The content of the inorganic filler is preferably 500 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the inorganic filler is 500 parts by weight or less, the adhesive reliability is improved or the flow is adjusted while maintaining excellent processability and the like. The upper limit with more preferable content of the said inorganic filler is 400 weight part.

The curable resin composition of the present invention 3 may contain an organic filler for the purpose of stress relaxation, imparting toughness and the like.

The preferable upper limit of the content of the organic filler is 500 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the organic filler is 500 parts by weight or less, the obtained cured product is excellent in toughness and the like while maintaining excellent adhesiveness and the like. The upper limit with more preferable content of the said organic filler is 400 weight part.

The curable resin composition of the present invention 3 may contain a polymer compound as long as the object of the present invention is not impaired. The polymer compound serves as a film forming component.

The polymer compound may have a reactive functional group.
When the polymer compound has a reactive functional group, examples of the reactive functional group that the polymer compound has include an amino group, a urethane group, an imide group, a hydroxyl group, a carboxyl group, and an epoxy group.

The curable resin composition of the present invention 3 may contain a reactive diluent as long as the object of the present invention is not impaired.
As the reactive diluent, a reactive diluent having two or more reactive functional groups in one molecule is preferable from the viewpoint of adhesion reliability.
As a reactive functional group which the said reactive diluent has, the thing similar to the reactive functional group which the high molecular compound mentioned above has is mentioned.

The curable resin composition of the present invention 3 may further contain additives such as a solvent, a coupling agent, a dispersant, a storage stabilizer, a bleed inhibitor, a flux agent, a leveling agent, and a flame retardant.

Examples of the method for producing the curable resin composition of the present invention 3 include the following methods.
A solid block imide oligomer is pulverized in advance using a pulverizer such as a jet mill, a ball mill, or a bead mill, and then dispersed in a dispersion medium in which the imide oligomer is not dissolved to obtain an imide oligomer dispersion. Next, using a mixer such as a homodisper, a universal mixer, a Banbury mixer, or a kneader, the curable resin, the imide oligomer dispersion, and other curing agents, curing accelerators, and inorganic fillers that are added as necessary ( And a method of mixing with a flow modifier) and the like.

Although the curable resin composition of the present invention 3 can be used for a wide range of applications, it can be suitably used for an electronic material application that requires particularly high heat resistance. For example, it can be used for die attach agents in aviation, in-vehicle electric control unit (ECU) applications, power device applications using SiC, and GaN. Also, for example, power overlay package adhesive, printed wiring board adhesive, flexible printed circuit board coverlay adhesive, copper-clad laminate, semiconductor bonding adhesive, interlayer insulation film, prepreg, LED sealing It can also be used for adhesives and adhesives for structural materials. Especially, it is used suitably for an adhesive agent use.
An adhesive comprising the curable resin composition of the present invention 3 (hereinafter also referred to as “adhesive of the present invention 3”) is also one aspect of the present invention. An adhesive film (curable resin composition film) can be obtained by a method such as drying after applying the adhesive of the present invention 3 on the film, and curing the adhesive film by curing the adhesive film. Obtainable. The cured product of the curable resin composition of the present invention 3 is also one aspect of the present invention. An adhesive film using the adhesive of the third invention is also one of the present invention.

According to the present invention, it is possible to provide a curable resin composition that is excellent in flow characteristics before curing and excellent in adhesiveness, heat resistance, and flex resistance after curing. Moreover, according to this invention, the hardened | cured material of this curable resin composition, and the adhesive agent, adhesive film, coverlay film, and printed wiring board which use this curable resin composition are provided. it can.
Moreover, according to this invention, the curable resin composition which can obtain the hardened | cured material which is excellent in storage stability and excellent in low linear expansion property, adhesiveness, and long-term heat resistance can be provided. Moreover, according to this invention, the adhesive agent and adhesive film which use the hardened | cured material of this curable resin composition, and this curable resin composition can be provided.
Furthermore, according to the present invention, it is possible to provide a curable resin composition that is excellent in flexibility and processability before curing and excellent in adhesion and heat resistance after curing. Moreover, according to this invention, the adhesive agent and adhesive film which use the hardened | cured material of this curable resin composition, and this curable resin composition can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Synthesis Example 1-1 (Production of Imide Oligomer 1-A))
17.4 parts by weight of 1,4-bis (2- (4-aminophenyl) -2-propyl) benzene (Mitsui Chemicals Fine, “Bisaniline P”) was added to N-methylpyrrolidone (Fuji Film Wako Pure Chemical Industries, Ltd.) ) It was dissolved in 200 parts by weight. To the resulting solution, 52.0 parts by weight of 4,4 ′-(4,4′-isopropylidenediphenoxy) diphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and the reaction was stirred at 25 ° C. for 2 hours. To obtain an amic acid oligomer solution. After removing N-methylpyrrolidone from the obtained amic acid oligomer solution under reduced pressure, the mixture was heated at 300 ° C. for 2 hours to obtain imide oligomer 1-A (imidation rate: 97%).
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that the imide oligomer 1-A was mainly composed of an imide oligomer represented by the following formula (16). The softening point of imide oligomer 1-A was 155 ° C.

(Synthesis Example 1-2 (Production of Imide Oligomer 1-B))
Synthesis Example except that 17.2 parts by weight of 1,4-bis (2- (4-aminophenyl) -2-propyl) benzene was changed to 21.8 parts by weight of 3-aminophenol (manufactured by Tokyo Chemical Industry Co., Ltd.) In the same manner as in 1-1, an imide oligomer 1-B (imidation ratio: 96%) was obtained.
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that the imide oligomer 1-B was mainly composed of an imide oligomer represented by the following formula (17). The softening point of imide oligomer 1-B was 134 ° C.

(Examples 1 to 9, Comparative Examples 1 and 2)
The respective materials were stirred and mixed so that the blending ratios described in Tables 1 and 2 were obtained, and the curable resin compositions of Examples 1 to 9 and Comparative Examples 1 and 2 were produced.
Each obtained curable resin composition was coated on a release PET film so as to have a thickness of 20 μm, and dried to obtain an adhesive film.
In addition, each curable resin composition obtained was applied onto a 25 μm-thick polyimide film (“Kapton 100H” manufactured by Toray DuPont Co., Ltd.) so as to have a thickness of 20 μm, and a polyimide film (cover) having an adhesive layer Lay film). The release PET film was peeled off from the obtained adhesive film, laminated with a laminator so as to have a thickness of 500 μm, and the temperature rising rate was 10 ° C./min. Using a rotary rheometer (“VAR-100” manufactured by Rheologicala). Tables 1 and 2 show the minimum melt viscosities measured under the conditions of min, frequency 1 Hz, strain 1%, and measurement temperature range of 60 ° C to 300 ° C.

<Evaluation>
The following evaluation was performed on each curable resin composition, adhesive film, or coverlay film obtained in Examples 1 to 9 and Comparative Examples 1 and 2. The results are shown in Tables 1 and 2.

(Leaching prevention)
After making holes of 5 mmφ in the coverlay films obtained in Examples 1 to 9 and Comparative Examples 1 and 2, 190 ° C. on a flexible copper-clad laminate having a copper wiring pattern of L / S = 100 μm / 100 μm, Heat press-bonding was performed under conditions of 3 MPa for 1 hour, and the resin length that had oozed out inside the hole was measured as the amount of leaching. “○” indicates no leaching (leaching amount is less than 0.2 mm), “△” indicates leaching amount is 0.2 mm or more and 0.5 mm or less, and leaching amount exceeds 0.5 mm. In the case of “x”, the leaching prevention property was evaluated.

(Fillability)
The coverlay films obtained in Examples 1 to 9 and Comparative Examples 1 and 2 were heated on a flexible copper-clad laminate having a copper wiring pattern of L / S = 100 μm / 100 μm at 190 ° C., 3 MPa for 1 hour. Crimping was performed, and the presence or absence of voids between the copper wiring patterns was observed with an optical microscope.
“Good” when there is no void between the wires and the filling property is good, “△” when a little void is observed between the wires but the filling property is generally good, and many voids between the wires Was observed, and the case where the filling property was insufficient was evaluated as “×”.

(Adhesiveness)
The PET film was peeled from the adhesive films obtained in Examples 1 to 9 and Comparative Examples 1 and 2, and a polyimide substrate (manufactured by Toray DuPont) was used on both sides of the adhesive layer while heating to 70 ° C. using a laminator. , “Kapton 200H”, 50 μmt). A hot press was performed under the conditions of 190 ° C., 3 MPa, and 1 hour to cure the adhesive layer, and then cut into a 1 cm width to obtain a test piece.
Using a tensile tester ("ORITEC", "UCT-500"), T-peeling was performed at a peeling rate of 20 mm / min, and the adhesive strength was measured.
The case where the adhesive force is 3.4 N / cm or more is “◯”, the case where it is 2.0 N / cm or more and less than 3.4 N / cm is “Δ”, the case where it is less than 2.0 N / cm Adhesiveness was evaluated as “×”.

(Heat resistance (glass transition temperature))
The PET film was peeled from the adhesive films obtained in Examples 1 to 9 and Comparative Examples 1 and 2, and laminated to a thickness of 500 μm using a laminator. The obtained laminated film was cured by heating at 190 ° C. for 30 minutes to produce a cured product. About the obtained cured product, using a thermomechanical analyzer (manufactured by Hitachi High-Tech Science Co., “TMA / SS-6000”), the load is 5 g, the heating rate is 10 ° C./min, and the sample length is 1 cm from 0 ° C. to 300 ° C. The inflection point of the SS curve obtained when the temperature was raised was determined as the glass transition temperature.

(Heat resistance (5% weight loss temperature))
The PET film was peeled from the adhesive films obtained in Examples 1 to 9 and Comparative Examples 1 and 2, and laminated to a thickness of 500 μm using a laminator. The obtained laminated film was cured by heating at 190 ° C. for 30 minutes to produce a cured product.
Using the thermogravimetric measuring device (manufactured by Hitachi High-Tech Science Co., “TG / DTA6200”), the cured product obtained was reduced by 5% in the temperature range of 30 ° C. to 500 ° C. under the temperature rising condition of 10 ° C./min. The temperature was measured.

(Heat resistance (long-term heat resistance))
The test piece obtained in the same manner as in the above “(Adhesiveness)” was heat-treated at 175 ° C. for 1000 hours. About the test piece after heat processing, the adhesive force was measured with the measuring method similar to said "(adhesiveness)".
The case where the adhesive force is 3.4 N / cm or more is “◯”, the case where it is 2.0 N / cm or more and less than 3.4 N / cm is “Δ”, the case where it is less than 2.0 N / cm The heat resistance (long-term heat resistance) was evaluated as “×”.

(Flexibility)
A pattern of a bending resistance test sample disclosed in JIS C 6471 was prepared on a polyimide flexible copper-clad substrate, and the coverlay films obtained in Examples 1 to 9 and Comparative Examples 1 and 2 were applied at 190 ° C., 3 MPa, A test piece was obtained by thermocompression bonding under conditions of 1 hour. With an FPC high-speed bending tester (manufactured by Shin-Etsu Engineering Co., Ltd.), the change in resistance value was measured under conditions of a frequency of 1500 cpm, a stroke of 20 mm, a curvature of 2.5 mmR, and the outside of the coverlay. Bending characteristics were evaluated by utilizing the fact that when cracks such as cracks occur in the copper foil due to bending, the volume decreases and the resistance increases. The number of times required for the resistance value to rise by 20% or more is measured. If it is 300,000 times or more, “○”, if it is 50,000 times to less than 300,000 times, “△”, 50,000 times The bending resistance was evaluated as “x” when the ratio was less than.

(Synthesis Example 2-1 (Production of Imide Oligomer 2-A))
19.2 parts by weight of 1,3-bis (3-aminophenoxy) benzene (manufactured by Mitsui Chemicals Fine, “APB-N”) is dissolved in 200 parts by weight of N-methylpyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries). It was. 62.0 parts by weight of 4,4′-oxydiphthalic dianhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the resulting solution, and the mixture was stirred at 25 ° C. for 2 hours to obtain an amic acid oligomer solution. After removing N-methylpyrrolidone from the obtained amic acid oligomer solution under reduced pressure, the mixture was heated at 300 ° C. for 2 hours to obtain imide oligomer 2-A (imidization rate: 95.0%).
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer 2-A is an imide oligomer represented by the formula (6) (X is a tetravalent compound represented by the formula (7-2)). It was confirmed that the main group Y was a divalent group represented by the formula (8-2) (Z was a divalent group having an aromatic ring represented by the following formula (18)). The softening point of imide oligomer 2-A was 138 ° C.

In formula (18), * is a bonding position.

(Synthesis Example 2-2 (Preparation of Imide Oligomer 2-B))
5.4 parts by weight of 1,3-phenylenediamine (“1,3-PDA” manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 200 parts by weight of N-methylpyrrolidone. To the resulting solution, 52.0 parts by weight of 4,4 ′-(4,4′-isopropylidenediphenoxy) diphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and the reaction was stirred at 25 ° C. for 2 hours. To obtain an amic acid oligomer solution. After removing N-methylpyrrolidone from the obtained amic acid oligomer solution under reduced pressure, the mixture was heated at 300 ° C. for 2 hours to obtain imide oligomer 2-B (imidization ratio: 93%).
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer 2-B is an imide oligomer represented by the formula (6) (X is a tetravalent compound represented by the formula (7-3)). It was confirmed that the group Y was mainly composed of a divalent group represented by the formula (8-4) (R ¹¹ to R ¹⁴ are hydrogen atoms). The softening point of imide oligomer 2-B was 146 ° C.

(Synthesis Example 2-3 (Production of Imide Oligomer 2-C))
Synthesis Example 2-2 except that 5.4 parts by weight of 1,3-phenylenediamine was changed to 5.4 parts by weight of 1,4-phenylenediamine (“1,4-PDA” manufactured by Tokyo Chemical Industry Co., Ltd.). In the same manner as above, an imide oligomer 2-C (imidation rate: 94%) was obtained.
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer 2-C is an imide oligomer represented by the formula (6) (X is a tetravalent compound represented by the formula (7-3)). It was confirmed that the group Y is a divalent group represented by the formula (8-3) (R ⁷ to R ¹⁰ are hydrogen atoms)) as a main component. The softening point of imide oligomer 2-C was 151 ° C.

(Synthesis Example 2-4 (Production of Imide Oligomer 2-D))
The same as Synthesis Example 2-2 except that 5.4 parts by weight of 1,3-phenylenediamine was changed to 12.4 parts by weight of 4,4′-diaminodiphenylsulfone (manufactured by Tokyo Chemical Industry Co., Ltd., “DDPS”). As a result, an imide oligomer 2-D (imidization rate of 95%) was obtained.
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer 2-D is a tetravalent imide oligomer represented by the formula (6) (X is represented by the formula (7-3)). It was confirmed that the group Y was mainly composed of a divalent group represented by the formula (8-1) (Z is a sulfonyl group). The softening point of imide oligomer 2-D was 147 ° C.

(Synthesis Example 2-5 (Production of Imide Oligomer 2-E))
Synthesis example except that 5.4 parts by weight of 1,3-phenylenediamine was changed to 21.6 parts by weight of bis (4- (3-aminophenoxy) phenyl) sulfone (manufactured by Tokyo Chemical Industry Co., Ltd., “BAPS”). In the same manner as in 2-2, imide oligomer 2-E (imidation rate: 97%) was obtained.
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer 2-E is a tetravalent imide oligomer represented by the formula (6) (X is represented by the formula (7-3)). It was confirmed that the main group Y was a divalent group represented by the formula (8-2) (Z was a divalent group having an aromatic ring represented by the following formula (19)). The softening point of imide oligomer 2-E was 147 ° C.

In formula (19), * is a bonding position.

(Synthesis Example 2-6 (Production of Imide Oligomer 2-F))
Synthesis was performed except that 5.4 parts by weight of 1,3-phenylenediamine was changed to 14.6 parts by weight of 1,3-bis (4-aminophenoxy) benzene (Tokyo Chemical Industry Co., Ltd., “TPE-R”). In the same manner as in Example 2-2, an imide oligomer 2-F (imidation ratio: 94%) was obtained.
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer 2-F was converted into an imide oligomer represented by the formula (6) (X is a tetravalent group represented by the formula (7-3)). It was confirmed that the group Y is a divalent group represented by the formula (8-1) (Z is a divalent group having an aromatic ring represented by the formula (18)) as a main component. The softening point of imide oligomer 2-F was 137 ° C.

(Synthesis Example 2-7 (Production of Imide Oligomer 2-G))
Imide oligomer 2 was prepared in the same manner as in Synthesis Example 2-2 except that 5.4 parts by weight of 1,3-phenylenediamine was changed to 8.9 parts by weight of diethyltoluenediamine (“Ethacure 100” manufactured by Albemarle). -G (imidation rate 98%) was obtained.
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer 2-G was converted into an imide oligomer represented by the formula (6) (X is a tetravalent group represented by the formula (7-3)). Group, Y is a divalent group represented by formula (8-4) (one of R ¹¹ and R ¹² is a methyl group, the other is an ethyl group, R ¹³ is a hydrogen atom, and R ¹⁴ is an ethyl group)) It was confirmed to be the main component. The softening point of imide oligomer 2-G was 150 ° C.

(Synthesis Example 2-8 (Production of Imide Oligomer 2-H))
An imide oligomer 2-H (imide) was prepared in the same manner as in Synthesis Example 2-1, except that 29.2 parts by weight of 1,3-bis (3-aminophenoxy) benzene was changed to 17.8 parts by weight of diethyltoluenediamine. Conversion rate 95%).
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer 2-H is an imide oligomer represented by the formula (6) (X is a tetravalent compound represented by the formula (7-2)). Group, Y is a divalent group represented by formula (8-4) (one of R ¹¹ and R ¹² is a methyl group, the other is an ethyl group, R ¹³ is a hydrogen atom, and R ¹⁴ is an ethyl group)) It was confirmed to be the main component. The softening point of imide oligomer 2-H was 183 ° C.

(Synthesis Example 2-9 (Production of Imide Oligomer 2-I))
The same procedure as in Synthesis Example 2-2 except that 5.4 parts by weight of 1,3-phenylenediamine was changed to 9.9 parts by weight of 4,4′-diaminodiphenylmethane (Tokyo Chemical Industry Co., Ltd., “DDM”). As a result, an imide oligomer 2-I (imidization rate of 95%) was obtained.
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer 2-I is a tetravalent imide oligomer represented by the formula (6) (X is represented by the formula (7-3)). It was confirmed that the group Y was mainly composed of a divalent group represented by the formula (8-1) (Z is a methylene group). The softening point of imide oligomer 2-I was 147 ° C.

(Synthesis Example 2-10 (Production of Imide Oligomer 2-J))
29.2 parts by weight of 1,3-bis (3-aminophenoxy) benzene was changed to 19.8 parts by weight of 4,4′-diaminodiphenylmethane, and 62.0 parts by weight of 4,4′-oxydiphthalic dianhydride was added. Imide oligomer 2-J (imidation rate: 96%) was obtained in the same manner as in Synthesis Example 2-1, except that the amount was changed to 58.8 parts by weight of 4,4′-biphthalic anhydride.
According to ¹ H-NMR, GPC, and FT-IR analysis, in imide oligomer 2-J, the portion corresponding to X in formula (6) is a biphenyl skeleton, and the portion corresponding to Y is represented by formula (8- It was confirmed that the main component was an imide oligomer which is a divalent group represented by 1) (Z is a methylene group). Further, the softening point of imide oligomer 2-J exceeded 300 ° C.

(Synthesis Example 2-11 (Production of Imide Oligomer 2-K))
Imide oligomer 2 was prepared in the same manner as in Synthesis Example 2-2, except that 5.4 parts by weight of 1,3-phenylenediamine was changed to 7.7 parts by weight of norbornane diamine (manufactured by Mitsui Chemicals Fine Co., Ltd., “NBDA”). -K (imidation rate 97%) was obtained.
According to ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer 2-K is a tetravalent group in which the portion corresponding to X in the formula (6) is represented by the formula (7-3). Yes, it was confirmed that the portion corresponding to Y was mainly composed of an imide oligomer having a norbornane skeleton. The softening point of imide oligomer 2-K was 137 ° C.

(Synthesis Example 2-12 (Production of Imide Oligomer 2-L))
Synthesis Example except that 62.0 parts by weight of 4,4′-oxydiphthalic dianhydride was changed to 26.0 parts by weight of 4,4 ′-(4,4′-isopropylidenediphenoxy) diphthalic anhydride In the same manner as in 2-1, imide oligomer 2-L (imidation rate: 94%) was obtained.
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that the imide oligomer 2-L was mainly composed of an imide oligomer represented by the following formula (20). The softening point of the imide oligomer 2-L was 132 ° C.

(Examples 10 to 20, Comparative Examples 3 to 7)
According to the blending ratios described in Tables 3 and 4, each material was stirred and mixed to prepare curable resin compositions of Examples 10 to 20 and Comparative Examples 3 to 7.

<Evaluation>
The following evaluation was performed on each curable resin composition obtained in Examples 10 to 20 and Comparative Examples 3 to 7. The results are shown in Tables 3 and 4.

(Storage stability)
For each of the curable resin compositions obtained in Examples 10 to 20 and Comparative Examples 3 to 7, the initial viscosity immediately after production and the viscosity after storage at 25 ° C. for 24 hours were measured. (Viscosity after storage for 24 hours at 25 ° C.) / (Initial viscosity) is the rate of change in viscosity. The storage stability was evaluated with “Δ” as the case of “た” and “×” as the case of 2.0 or more.
The viscosity of the curable resin composition was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., “TPE-100”) at 25 ° C. and a rotational speed of 5 rpm.

(Linear expansion coefficient and glass transition temperature)
The curable resin compositions obtained in Examples 10 to 20 and Comparative Examples 3 to 7 were coated on a release PET film and dried to obtain an adhesive film. The PET film was peeled off from the obtained adhesive film, laminated, and cured by heating at 190 ° C. for 1 hour to prepare a cured product having a thickness of 400 μm.
Using the thermomechanical analyzer (“TMA / SS-6000” manufactured by Hitachi High-Tech Science Co., Ltd.), the resulting cured product was subjected to a load of 5 g, a heating rate of 10 ° C./min, and a sample length of 1 cm to 0 ° C. to 300 ° C. After the temperature was raised to 0 ° C., it was once cooled, and again heated from 0 ° C. to 300 ° C. under the same conditions. Based on the temperature and dimensional change data obtained in the second measurement, the average linear expansion coefficient in the temperature range of 40 ° C. to 80 ° C. was obtained and used as the linear expansion coefficient of the sample. Further, the inflection point of the graph showing the relationship between the temperature and the dimensional change obtained in the second measurement was determined as the glass transition temperature.

(5% weight loss temperature)
The curable resin compositions obtained in Examples 10 to 20 and Comparative Examples 3 to 7 were coated on a release PET film and dried to obtain an adhesive film. The PET film was peeled from the obtained adhesive film and cured by heating at 190 ° C. for 1 hour to prepare a cured product.
Using the thermogravimetric measuring device (manufactured by Hitachi High-Tech Science Co., “TG / DTA6200”), the cured product obtained was reduced by 5% in the temperature range of 30 ° C. to 500 ° C. under the temperature rising condition of 10 ° C./min. The temperature was measured.

(Initial adhesion)
Each curable resin composition obtained in Examples 10 to 20 and Comparative Examples 3 to 7 was coated on a release PET film so as to have a thickness of about 20 μm, and dried to obtain an adhesive film. . The PET film was peeled off from the adhesive film, and a polyimide substrate (manufactured by Toray DuPont, “Kapton 200H”, 50 μmt) was bonded to both surfaces of the adhesive layer using a laminator while heating to 70 ° C. A hot press was performed under the conditions of 190 ° C., 3 MPa, and 1 hour to cure the adhesive layer, and then cut into a 1 cm width to obtain a test piece.
Using a tensile tester ("ORITEC", "UCT-500"), T-peeling was performed at a peeling rate of 20 mm / min, and the adhesive strength was measured.
The case where the adhesive force is 3.4 N / cm or more is “◯”, the case where it is 2.0 N / cm or more and less than 3.4 N / cm is “Δ”, the case where it is less than 2.0 N / cm Initial adhesiveness was evaluated as “×”.

(Long-term heat resistance)
The test piece obtained in the same manner as the above “(initial adhesiveness)” was heat-treated at 175 ° C. for 1000 hours. The test pieces after the heat treatment were subjected to T-peeling at a peeling rate of 20 mm / min using a tensile testing machine (“UCT-500” manufactured by ORIENTEC), and the adhesive strength was measured.
The case where the adhesive force is 3.4 N / cm or more is “◯”, the case where it is 2.0 N / cm or more and less than 3.4 N / cm is “Δ”, the case where it is less than 2.0 N / cm Long-term heat resistance was evaluated as “×”.

(Synthesis Example 3-1 (Production of Imide Oligomer 3-A))
10 parts by weight of 4,4′-diaminodiphenyl ether (Tokyo Chemical Industry Co., Ltd., “DDPE”) was dissolved in 200 parts by weight of N-methylpyrrolidone (Fuji Film Wako Pure Chemical Industries, Ltd.). To the resulting solution, 52.0 parts by weight of 4,4 ′-(4,4′-isopropylidenediphenoxy) diphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and the reaction was stirred at 25 ° C. for 2 hours. To obtain an amic acid oligomer solution. After removing N-methylpyrrolidone from the obtained amic acid oligomer solution under reduced pressure, the mixture was heated at 300 ° C. for 2 hours to obtain imide oligomer 3-A (imidization rate: 92%).
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that the imide oligomer 3-A was mainly composed of an imide oligomer represented by the following formula (21). The softening point of imide oligomer 3-A was 147 ° C., and the melting point was 168 ° C.

(Synthesis Example 3-2 (Production of Imide Oligomer 3-B))
The same as Synthesis Example 3-1 except that 10 parts by weight of 4,4′-diaminodiphenyl ether was changed to 5.4 parts by weight of 1,4-phenylenediamine (“1,4-PDA” manufactured by Tokyo Chemical Industry Co., Ltd.) In this way, an imide oligomer 3-B (imidization rate 95%) was obtained.
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that the imide oligomer 3-B was mainly composed of an imide oligomer represented by the following formula (22). The softening point of imide oligomer 3-B was 151 ° C., and the melting point was 168 ° C.

(Synthesis Example 3-3 (Production of Imide Oligomer 3-C))
21.6 parts by weight of bis (4- (3-aminophenoxy) phenyl) sulfone (manufactured by Tokyo Chemical Industry Co., Ltd., “BAPS”) was dissolved in 200 parts by weight of N-methylpyrrolidone. To the resulting solution, 31.0 parts by weight of 4,4′-oxydiphthalic dianhydride (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added and reacted by stirring at 25 ° C. for 2 hours to obtain an amic acid oligomer solution. After removing N-methylpyrrolidone from the obtained amic acid oligomer solution under reduced pressure, the mixture was heated at 300 ° C. for 2 hours to obtain imide oligomer 3-C (imidation rate: 98%).
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that the imide oligomer 3-C was mainly composed of an imide oligomer represented by the following formula (23). The softening point of imide oligomer 3-C was 166 ° C., and the melting point was 181 ° C.

(Synthesis Example 3-4 (Production of Imide Oligomer 3-D))
17.2 parts by weight of 1,4-bis (2- (4-aminophenyl) -2-propyl) benzene (“Bisaniline P” manufactured by Mitsui Chemical Fine Co., Ltd.) was dissolved in 200 parts by weight of N-methylpyrrolidone. To the resulting solution, 32.2 parts by weight of 4,4′-carbonyldiphthalic dianhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and reacted by stirring at 25 ° C. for 2 hours to obtain an amic acid oligomer solution. It was. After removing N-methylpyrrolidone from the obtained amic acid oligomer solution under reduced pressure, the mixture was heated at 300 ° C. for 2 hours to obtain imide oligomer 3-D (imidation rate: 96%).
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that imide oligomer 3-D was mainly composed of an imide oligomer represented by the following formula (24). The softening point of imide oligomer 3-D was 228 ° C., and the melting point was 273 ° C.

(Synthesis Example 3-5 (Production of Imide Oligomer 3-E))
1,4 parts by weight of 4,4′-diamino-3,3′-dihydroxybiphenyl (Tokyo Chemical Industry Co., Ltd.) was dissolved in 200 parts by weight of N-methylpyrrolidone (Fuji Film Wako Pure Chemical Industries, Ltd.). To the resulting solution, 52.0 parts by weight of 4,4 ′-(4,4′-isopropylidenediphenoxy) diphthalic anhydride was added and stirred at 25 ° C. for 2 hours to react to give an amic acid oligomer (A ) Was obtained. After removing N-methylpyrrolidone from the obtained amic acid oligomer solution under reduced pressure, the mixture was heated at 300 ° C. for 2 hours to obtain an imide oligomer having an acid anhydride group at the terminal (imidation rate 95%).
Further, 61.6 parts by weight of the obtained imide oligomer was weighed and dissolved in 200 parts by weight of N-methylpyrrolidone, and then 10.9 parts by weight of 3-aminophenol (manufactured by Tokyo Chemical Industry Co., Ltd.) was added. The solution was stirred at 2 ° C. for 2 hours to obtain an amic acid oligomer (B) solution. N-methylpyrrolidone was removed under reduced pressure from the solution of the obtained amic acid oligomer (B), and then heated at 300 ° C. for 2 hours to obtain imide oligomer 3-E (imidation ratio 93%).
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that the imide oligomer 3-E was mainly composed of an imide oligomer represented by the following formula (25). The softening point of imide oligomer 3-E was 198 ° C., and the melting point was 223 ° C.

(Synthesis Example 3-6 (Production of Imide Oligomer 3-F))
Changed 10 parts by weight of 4,4′-diaminodiphenyl ether to 17.2 parts by weight of 1,3-bis (2- (4-aminophenyl) -2-propyl) benzene (“Bisaniline M” manufactured by Mitsui Chemical Fine Co., Ltd.) Except for this, in the same manner as in Synthesis Example 3-1, an imide oligomer 3-F (imidation ratio 94%) was obtained.
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that the imide oligomer 3-F was mainly composed of an imide oligomer represented by the following formula (26). The softening point of imide oligomer 3-F was 145 ° C. and the melting point was 158 ° C.

(Synthesis Example 3-7 (Production of Imide Oligomer 3-G))
10.9 parts by weight of 3-aminophenol was dissolved in 200 parts by weight of N-methylpyrrolidone. To the resulting solution was added 26.0 parts by weight of 4,4 ′-(4,4′-isopropylidenediphenoxy) diphthalic anhydride, and the mixture was stirred at 25 ° C. for 2 hours to react to give an amic acid oligomer solution. Obtained. After removing N-methylpyrrolidone from the obtained amic acid oligomer solution under reduced pressure, the mixture was heated at 300 ° C. for 2 hours to obtain imide oligomer 3-G (imidation rate 95%).
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that the imide oligomer 3-G was mainly composed of an imide oligomer represented by the following formula (27). The softening point of imide oligomer 3-G was 137 ° C., and the melting point was 155 ° C.

(Synthesis Example 3-8 (Production of Imide Oligomer 3-H))
Same as Synthesis Example 3-1, except that 10 parts by weight of 4,4′-diaminodiphenyl ether was changed to 5.4 parts by weight of 1,3-phenylenediamine (“1,3-PDA”, manufactured by Tokyo Chemical Industry Co., Ltd.) As a result, an imide oligomer 3-H (imidization rate of 95%) was obtained.
It was confirmed by ¹ H-NMR, GPC, and FT-IR analysis that the imide oligomer 3-H was mainly composed of the imide oligomer represented by the formula (28). The softening point of imide oligomer 3-H was 146 ° C. and the melting point was 163 ° C.

(Examples 21 to 31, Comparative Examples 8 and 9)
The imide oligomers 3-A to 3-H obtained in Synthesis Examples 3-1 to 3-8 were pulverized using a jet mill and then mixed with methyl ethyl ketone to obtain a mixed solution (average particles of each imide oligomer). Diameter 4-10 μm). The imide oligomers 3-A to 3-E and 3-H were insoluble in methyl ethyl ketone, but the imide oligomers 3-F and 3-G were dissolved in methyl ethyl ketone. Next, the obtained mixed liquid and other materials were stirred and mixed so that each material had a blending ratio described in Table 5, and the curable resin compositions of Examples 21 to 31 and Comparative Examples 8 and 9 were mixed. A product was made.
About each obtained curable resin composition, the dispersion state of the imide oligomer in 25 degreeC was confirmed by optical microscope observation. As a result, it was confirmed that in each of the curable resin compositions of Examples 21 to 31 using imide oligomers 3-A to 3-E and 3-H, the imide oligomer was dispersed in solid particles. On the other hand, in each of the curable resin compositions of Comparative Examples 8 and 9 using only the imide oligomer 3-F or 3-G, it was confirmed that the imide oligomer was dissolved.

<Evaluation>
The following evaluation was performed on each curable resin composition obtained in Examples 21 to 31 and Comparative Examples 8 and 9. The results are shown in Table 5.

(Flexibility)
The curable resin compositions obtained in Examples 21 to 31 and Comparative Examples 8 and 9 were coated on a release PET film and dried to obtain an adhesive film. The obtained adhesive film was subjected to a 5 mm diameter winding test to be wound around a 5 mm diameter cylinder at 25 ° C., and cracking or chipping of the adhesive film was confirmed. Moreover, the 180 degree bending test which bends the obtained adhesive film 180 degree | times was done, and the crack and the chip | tip of the adhesive film were confirmed.
The case where there was no crack or chipping in both the 5 mm diameter winding test and the 180 degree bending test was “O”, and the 5 mm diameter winding test was free of cracking or chipping, but the 180 degree bending test was free of cracking or chipping. Flexibility was evaluated as “Δ” when there was a crack and “x” when there was a crack or chip in both tests.

(Processability)
The curable resin compositions obtained in Examples 21 to 31 and Comparative Examples 8 and 9 were coated on a release film and dried to obtain an adhesive film. The obtained adhesive film was punched using a Thomson blade, and the state of the fracture surface and the presence or absence of powder fall were confirmed.
did. The processability was evaluated with “◯” when the fracture surface was smooth and no powder falling, and “X” when the fracture surface was not smooth and there was powder fall.

(Adhesiveness)
Each curable resin composition obtained in Examples 21 to 31 and Comparative Examples 8 and 9 was coated on a release PET film so as to have a thickness of about 20 μm, and dried to obtain an adhesive film. . The PET film was peeled off from the adhesive film, and a polyimide substrate (manufactured by Toray DuPont, “Kapton 200H”, 50 μmt) was bonded to both surfaces of the adhesive layer using a laminator while heating to 70 ° C. A hot press was performed under the conditions of 190 ° C., 3 MPa, and 1 hour to cure the adhesive layer, and then cut into a 1 cm width to obtain a test piece.
Using a tensile tester ("ORITEC", "UCT-500"), T-peeling was performed at a peeling rate of 20 mm / min, and the adhesive strength was measured.
When the adhesive strength is 6.0 N or more, “「 ”, when 3.4 N / cm or more and less than 6.0 N / cm,“ ◯ ”, when 2.0 N / cm or more and less than 3.4 N / cm The adhesiveness was evaluated as “Δ” when it was present and “×” when it was less than 2.0 N / cm.

(Heat resistance (glass transition temperature))
The curable resin compositions obtained in Examples 21 to 31 and Comparative Examples 8 and 9 were coated on a release PET film and dried to obtain curable resin composition films. The PET film was peeled from the obtained curable resin composition film, laminated using a laminator, and then cured by heating at 190 ° C. for 1 hour to prepare a cured product having a thickness of 500 μm. About the obtained cured product, using a thermomechanical analyzer (manufactured by Hitachi High-Tech Science Co., “TMA / SS-6000”), the load is 5 g, the heating rate is 10 ° C./min, and the sample length is 1 cm from 0 ° C. to 300 ° C. The inflection point of the SS curve obtained when the temperature was raised was determined as the glass transition temperature.

(Heat resistance (5% weight loss temperature))
The curable resin compositions obtained in Examples 21 to 31 and Comparative Examples 8 and 9 were coated on a release film and dried to obtain an adhesive film. The obtained adhesive film was cured by heating at 190 ° C. for 1 hour to produce a cured product.
Using the thermogravimetric measuring device (manufactured by Hitachi High-Tech Science Co., “TG / DTA6200”), the cured product obtained was reduced by 5% in the temperature range of 30 ° C. to 500 ° C. under the temperature rising condition of 10 ° C./min. The temperature was measured.

Claims

Containing a thermosetting resin, a thermoplastic resin and an imide oligomer,
The said imide oligomer has the reactive functional group which can react with the said thermosetting resin, The curable resin composition characterized by the above-mentioned.
The curable resin composition according to claim 1, wherein the thermosetting resin contains an epoxy resin.
The curable resin composition according to claim 1, wherein the thermoplastic resin contains a phenoxy resin.
The curing according to claim 1, 2, or 3, wherein a content of the thermoplastic resin in a total of 100 parts by weight of the thermosetting resin, the thermoplastic resin, and the imide oligomer is 1 part by weight or more and 60 parts by weight or less. Resin composition.
The curable resin composition according to claim 1, wherein the reactive functional group is an acid anhydride group and / or a phenolic hydroxyl group.
The curable resin composition according to claim 1, wherein the imidization ratio of the imide oligomer is 70% or more.
The curable resin composition according to claim 1, which has a minimum melt viscosity of 5 kPa · s to 300 kPa · s.
An adhesive comprising the curable resin composition according to claim 1, 2, 3, 4, 5, 6 or 7.
Hardened | cured material of the curable resin composition of Claim 1, 2, 3, 4, 5, 6 or 7.
An adhesive film using the adhesive according to claim 8.
The coverlay film which has the contact bonding layer which consists of hardened | cured material of Claim 9, and an insulating film.
The flexible printed wiring board which has a coverlay film of Claim 11.
A curable resin composition containing a curable resin, an imide oligomer, and a curing accelerator,
The said imide oligomer is represented by following formula (6), The curable resin composition characterized by the above-mentioned.

In the formula (6), X is a tetravalent group represented by the following formula (7-1), (7-2), or (7-3), and Y is a formula (8-1) ), (8-2), (8-3), or (8-4).

In the formulas (7-1) to (7-3), * is a bonding position. The hydrogen atom of the aromatic ring in formulas (7-1) to (7-3) may be substituted.

In formulas (8-1) and (8-2), Z represents a bond, an oxygen atom, a sulfonyl group, or a linear or branched divalent carbon atom which may have an oxygen atom at the bonding position. It is a hydrogen group or a divalent group having an aromatic ring which may have an oxygen atom at the bonding position. The hydrogen atom of the aromatic ring in formulas (8-1) and (8-2) may be substituted. In formulas (8-3) and (8-4), R 7 to R 14 each represents a hydrogen atom or a monovalent hydrocarbon group, and may be the same or different. In formulas (8-1) to (8-4), * represents a bonding position.
The curable resin composition according to claim 13, wherein the curable resin contains an epoxy resin.
The curable oligomer composition according to claim 13 or 14, wherein the imide oligomer has a softening point of 250 ° C or lower.
The curable resin composition according to claim 13, 14 or 15, wherein the imidization ratio of the imide oligomer is 70% or more.
The curable resin composition according to claim 13, 14, 15, or 16, wherein the curing accelerator is a basic catalyst.
The curable resin composition according to claim 13, 14, 15, 16, or 17, wherein the curing accelerator has an imidazole skeleton.
The content of the curing accelerator in a total of 100 parts by weight of the curable resin, the imide oligomer, and the curing accelerator is 0.8 part by weight or more and 10 parts by weight or less. The curable resin composition according to 17, 17 or 18.
A cured product of the curable resin composition according to claim 13, 14, 15, 16, 17, 18 or 19.
The hardened | cured material of Claim 20 whose average linear expansion coefficient in the temperature range of 40 to 80 degreeC is 60 ppm or less.
An adhesive comprising the curable resin composition according to claim 13, 14, 15, 16, 17, 18 or 19.
An adhesive film comprising the curable resin composition according to claim 13, 14, 15, 16, 17, 18 or 19.
A curable resin composition containing a curable resin and an imide oligomer,
The curable resin is liquid at 25 ° C.
A curable resin composition, wherein the imide oligomer is dispersed in solid particles at 25 ° C.
The curable resin composition according to claim 24, wherein the curable resin contains an epoxy resin.
26. The curable resin composition according to claim 24 or 25, wherein the imide oligomer has a reactive functional group capable of reacting with the curable resin.
27. The curable resin composition according to claim 26, wherein the reactive functional group is an acid anhydride group and / or a phenolic hydroxyl group.
28. The curable resin composition according to claim 24, 25, 26 or 27, wherein the imide oligomer has a softening point of 250 ° C. or lower.
29. The curable resin composition according to claim 24, 25, 26, 27 or 28, wherein the imidization ratio of the imide oligomer is 70% or more.
The said imide oligomer contains the imide oligomer which is insoluble in a curable resin composition at 25 degreeC, and the imide oligomer which can be melt | dissolved in a curable resin composition at 25 degreeC, 25, 26, 27, 28 Or the curable resin composition of 29.
31. The curable resin composition according to claim 30, wherein a content ratio of the imide oligomer that can be dissolved in the curable resin composition at 25 ° C. is 80 parts by weight or less in 100 parts by weight of the whole imide oligomer.
A cured product of the curable resin composition according to claim 24, 25, 26, 27, 28, 29, 30 or 31.
An adhesive comprising the curable resin composition according to claim 24, 25, 26, 27, 28, 29, 30 or 31.
An adhesive film using the adhesive according to claim 33.