TWI797117B - Imide oligomer, curing agent, adhesive, and method for producing imide oligomer - Google Patents

Abstract

An object of the present invention is to provide an imide oligomer which can be used for cured products excellent in long-term heat resistance. Furthermore, the object of the present invention is to provide a curing agent composed of the imide oligomer and an adhesive using the curing agent. Furthermore, the object of the present invention is to provide a method for producing the imide oligomer.

The present invention is an imide oligomer having a phenolic hydroxyl group, and the content ratio of the imide oligomer having an ester bond is 7% or less.

Description

Imide oligomer, curing agent, adhesive, and method for producing imide oligomer

The present invention relates to an imide oligomer which can be used for cured products excellent in long-term heat resistance. Also, the present invention relates to a curing agent composed of the imide oligomer, and an adhesive using the curing agent. Furthermore, the present invention relates to a method for producing the imide oligomer.

Hardening resins such as epoxy resins that have low shrinkage and excellent adhesiveness, insulation, and chemical resistance are used in many industrial products. Especially in the application of electronic equipment, it is often used as a curable resin composition that can obtain good results in the short-term heat resistance reflow test or the repeated heat resistance cycle test.

In recent years, automotive electronic control units (ECUs) and power devices using SiC and GaN have attracted attention, but curable resin compositions used in these applications do not require short-term or repeated heat resistance. Rather, heat resistance when exposed to high temperature continuously and for a long period of time (long-term heat resistance) is required.

As a curing agent for a curable resin composition, Patent Document 1 discloses an imide oligomer curing agent having an acid anhydride structure at both ends, but due to poor compatibility with curable resins such as epoxy resins, Therefore, there is a problem that the obtained curable resin composition is poor in long-term heat resistance.

On the other hand, in Patent Documents 2 and 3, in order to improve compatibility with curable resins, polyimide introduced with a flexible polysiloxane skeleton or alicyclic skeleton is disclosed as a curing agent. permanent resin composition. However, if a polysiloxane skeleton or an alicyclic skeleton is introduced, there is a problem that the glass transition temperature of the obtained cured product tends to drop, and the mechanical strength or long-term heat resistance at the operating temperature of the ECU or power device is poor. By. In addition, Patent Document 4 discloses that the adhesiveness, heat resistance, etc. of a thermosetting resin composition are improved by using a specific imide oligomer having phenolic hydroxyl groups at both ends as a curing agent, However, when such an imide oligomer is used, the long-term heat resistance may be lowered.

prior art literature patent documents

Patent Document 1: Japanese Patent Application Laid-Open No. 61-270852

Patent Document 2: Japanese Patent Laid-Open No. 2016-20437

Patent Document 3: Japanese Patent Laid-Open No. 2012-227534

Patent Document 4: International Publication No. 2005/100433

An object of the present invention is to provide an imide oligomer which can be used for cured products excellent in long-term heat resistance. Furthermore, the object of the present invention is to provide a curing agent composed of the imide oligomer and an adhesive using the curing agent. Furthermore, the object of the present invention is to provide a method for producing the imide oligomer.

The present invention is an imide oligomer having a phenolic hydroxyl group, and the content ratio of the imide oligomer having an ester bond is 7% or less.

Hereinafter, the present invention will be described in detail.

The inventors of the present invention have found that among imide oligomers having phenolic hydroxyl groups, those with ester bonds are not effective in improving the long-term heat resistance of the cured product when used as a hardening agent, which is beneficial to use. Amide oligomers with phenolic hydroxyl groups and no ester linkages were studied. However, even when an imide oligomer having a phenolic hydroxyl group and having no ester bond is used, the long-term heat resistance of the cured product cannot be sufficiently improved. The inventors of the present invention think that the reason why the long-term heat resistance of the cured product cannot be sufficiently improved is that in the imide oligomer having a phenolic hydroxyl group used as one having no ester bond, there is a small amount of imide oligomer having an ester bond as an impurity. imide oligomers. Therefore, the inventors of the present invention conducted intensive research and found that by using an imide oligomer having a phenolic hydroxyl group in which the content ratio of the imide oligomer having an ester bond, which will be an impurity, is 7% or less , A cured product excellent in long-term heat resistance can be obtained, thus completing the present invention.

The imide oligomer of the present invention has a phenolic hydroxyl group.

In the imide oligomer of the present invention, the content ratio of the imide oligomer having an ester bond is 7% or less. By making the content ratio of the imide oligomer having an ester bond 7% or less, the imide oligomer of the present invention has the effect of improving the long-term heat resistance of the cured product obtained when it is used as a curing agent Excellent. The content ratio of the above-mentioned imide oligomer having an ester bond is preferably 5% or less, most preferably 0%, that is, the above-mentioned imide oligomer having an ester bond is not contained.

Furthermore, the content ratio of the above-mentioned imide oligomers having ester bonds can be obtained by Fourier Transform Infrared Spectroscopy (FT-IR) after using gel permeation chromatography (GPC) to separate the peaks from the Calculated from the weight ratio of the compound that absorbs the ester bond. Specifically, first, tetrahydrofuran (THF) was used in the free liquid, and a recirculating HPLC (manufactured by Japan Analytical Industry Co., Ltd.) equipped with a GPC column (for example, "JAIGEL-2H" manufactured by Japan Analytical Industry Co., Ltd.) was used for fractionation. Take each peak. Thereafter, the compound obtained by removing the free liquid by heating or the like is measured by a total reflectance measurement method (ATR method) using a Fourier transform infrared spectrophotometer (for example, "UMA600" manufactured by Agilent Technologies, etc.). It was derived by obtaining the weight ratio of the compound having a peak (1159 cm ^-1 ) derived from an ester bond to the weight of all peak compounds from the obtained measurement results.

From the viewpoint of the long-term heat resistance of the obtained cured product, the imide oligomer of the present invention preferably has a phenolic hydroxyl group at the terminal of the main chain, and more preferably has a phenolic hydroxyl group at both terminals.

The preferred lower limit of the number average molecular weight of the imide oligomer of the present invention is 400, and the preferred upper limit is 4200. When the number average molecular weight is within this range, the cured product obtained when the imide oligomer of the present invention is used as a curing agent is excellent in long-term heat resistance. The more preferable lower limit of the number average molecular weight of the imide oligomer of the present invention is 420, and the more preferable upper limit is 4000.

In addition, in this specification, the said "number average molecular weight" is the value calculated|required by the polystyrene conversion measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent. As a column used when measuring the number average molecular weight based on polystyrene conversion by GPC, JAIGEL-2H-A (made by Japan Analytical Industry Co., Ltd.) etc. are mentioned, for example.

Specifically, the imide oligomer of the present invention preferably contains the imide oligomer represented by the following formula (1-1) and/or the imide oligomer represented by the following formula (1-2) Amine oligomer as the main component.

In addition, in this specification, the said "main component" means that a content rate is 60 mol% or more.

In formulas (1-1) and (1-2), R ¹ and R ² are independently a hydrogen atom, a halogen atom, or a valent hydrocarbon group that can be substituted, and X is a bond, an oxygen atom, or a Substituted divalent hydrocarbon group, in formula (1-2), Y is a bond, an oxygen atom, or a divalent hydrocarbon group that may be substituted.

As a method for producing the imide oligomer of the present invention, a method in which the amount of the monoamine having a phenolic hydroxyl group used as a raw material is made in excess can be preferably used.

A method for producing an imide oligomer is also one of the present invention. The method for producing an imide oligomer includes the step of reacting a compound having an acid anhydride group with a monoamine having a phenolic hydroxyl group, and the above-mentioned compound having a phenolic hydroxyl group The usage-amount of the monoamine of a reactive hydroxyl group is 1.5 equivalents or more with respect to the acid anhydride group of the compound which has an acid anhydride group mentioned above. According to the method for producing an imide oligomer of the present invention, the imide oligomer of the present invention in which the content ratio of the imide oligomer having an ester bond produced as a by-product is 7% or less can be easily produced Polymer.

The specific example of the manufacturing method of the imide oligomer of this invention is shown below.

First, the monoamine having a phenolic hydroxyl group is dissolved in a solvent (such as N,N-dimethylformamide, etc.) that can dissolve the amide acid oligomer obtained by the reaction. Acid dianhydride was added to the solution to react to obtain an amide acid oligomer solution. Then, the operation of adding the obtained amide acid oligomer solution to hydrochloric acid or the like was performed several times, and the precipitate was collected. The obtained precipitate is heated to advance the imidization reaction, whereby an imide oligomer having a phenolic hydroxyl group can be obtained. In the case of using this method, by setting the amount of the monoamine having the phenolic hydroxyl group used above to 1.5 equivalents or more relative to the acid anhydride group that the acid dianhydride has, the oligoimide having the ester bond can be made The content ratio of the polymer is 7% or less.

Moreover, another specific example of the manufacturing method of the imide oligomer of this invention is shown below.

First, diamine is dissolved in a solvent (such as N,N-dimethylformamide, etc.) that can dissolve the amide acid oligomer obtained by the reaction in advance, and acid diamine is added to the obtained solution. Anhydride is reacted to obtain a solution of an amide acid oligomer (A) having acid anhydride groups at both ends. A monoamine having a phenolic hydroxyl group is added and reacted to the obtained solution of the amide acid oligomer (A) to obtain a solution of the amide acid oligomer (B). Then, the following operation was performed several times: adding the solution of the obtained amide acid oligomer (B) to hydrochloric acid or the like, and recovering the precipitate. The obtained precipitate is heated to advance the imidization reaction, whereby an imide oligomer having a phenolic hydroxyl group can be obtained. In the case of using this method, by setting the usage amount of the above-mentioned monoamine having a phenolic hydroxyl group to 1.5 equivalents or more relative to the acid anhydride group of the above-mentioned amide acid oligomer (A), the monoamine having an ester bond can be The content ratio of the imide oligomer is 7% or less.

As the monoamine having the above-mentioned phenolic hydroxyl group, a compound represented by the following formula (2) can be preferably used.

Specific examples of the monoamine having a phenolic hydroxyl group include: 3-aminophenol, 4-aminophenol, 4-amino-o-cresol, 5-amino-o-cresol, 4-aminophenol, Amino-2,3-xylenol, 4-amino-2,5-xylenol, 4-amino-2,6-xylenol, 4-amino-1-naphthol, 5-amine Base-2-naphthol, 6-amino-1-naphthol, 4-amino-2,6-diphenylphenol, etc. Among these, 3-aminophenol, 4-aminophenol, and 4-amino-o-methanol are preferable in terms of obtaining a hardened product having excellent availability and storage stability and a high glass transition temperature. Phenol, 5-amino-o-cresol.

In formula (2), Ar is a divalent aromatic group that may be substituted, and R ³ and R ⁴ are each independently a hydrogen atom or a valent hydrocarbon group that may be substituted.

As said acid dianhydride, the compound represented by following formula (3) can be used preferably.

As said acid dianhydride, specifically, for example, pyromelite dianhydride, 3,3'-oxydiphthalic dianhydride, 3,4'-oxydiphthalic dianhydride, 4 ,4'-Oxydiphthalic dianhydride, 4,4'-(4,4'-isopropylidene diphenoxy)bisphthalic anhydride, 4,4'-bis(3,4 -dicarboxyphenoxy)diphenyl ether, p-phenylene bis(trimellitic anhydride), 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyl Tetracarboxylic dianhydride, 4,4'-carbonyldiphthalic dianhydride, etc. Among them, 4,4'-(4,4'-isopropylidene diphenoxy)bisphthalic anhydride, 3, 4'-oxydiphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, 4,4'-carbonyldiphthalic dianhydride.

In formula (3), A is a tetravalent group represented by the following formula (4-1) or the following formula (4-2).

In formula (4-1) and formula (4-2), * is bonding position, and in formula (4-1), Z is bonding bond, oxygen atom, carbonyl, or can be substituted at bonding position A divalent hydrocarbon group with an oxygen atom. The hydrogen atoms of the aromatic rings in formula (4-1) and formula (4-2) may be substituted.

As said diamine, the compound represented by following formula (5) can be used preferably.

Specific examples of the diamine 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'-diaminodiphenylene, 4,4'-diaminodiphenylene, bis(4-(3-aminophenoxy)phenyl ) Phenyl, bis(4-(4-aminophenoxy)phenyl)pyridine, 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 Phenoxy)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'-dihydroxydiphenylmethane, 4,4'-diamino-3,3'-dihydroxydiphenylmethane, 3,3 '-Diamino-4,4'-dihydroxydiphenyl ether, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 2,2-bis(3-hydroxy-4-amino Phenyl) propane, bisaminophenyl fluorine, bistoluidine, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diamino-3,3'-bis Hydroxydiphenyl ether, 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-2,2'-dihydroxybiphenyl, 4,4'-diamine Base-3,3'-dihydroxybiphenyl, 4,4'-bis(4-aminobenzamide)-3,3'-dihydroxybiphenyl, 4,4'-bis(3-amino Benzamide)-3,3'-dihydroxybiphenyl, etc. Among them, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 1,2-benzene Diamine, 1,3-phenylenediamine, 1,4-phenylenediamine, bis(4-(3-aminophenoxy)phenyl)pyridine, bis(4-(4-aminophenoxy) Phenyl)phenyl, 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene, 1,4-bis(2-(4-aminophenyl)-2-propyl )benzene.

In the formula (5), B is a divalent group represented by the following formula (6-1) or the following formula (6-2), and R ⁵ to R ⁸ are each independently a hydrogen atom or a monovalent hydrocarbon group.

In formula (6-1) and formula (6-2), * is a bond position, and in formula (6-1), Y is a bond, an oxygen atom, or a divalent hydrocarbon group that may be substituted. The phenylene groups in formula (6-1) and formula (6-2) may have some or all of the hydrogen atoms substituted by hydroxyl groups.

The preferred lower limit of the imidization rate of the imide oligomer of the present invention is 70%. When the above-mentioned imidization rate is 70% or more, when used as a curing agent, a cured product having excellent mechanical strength at high temperature and long-term heat resistance can be obtained. A more preferable lower limit of the above-mentioned imidization rate is 75%, and a more preferable lower limit is 80%. Also, there is no particularly preferable upper limit for the imidization rate of the imide oligomer of the present invention, but the actual upper limit is 98%.

In addition, the said "imidization rate" can be calculated|required by Fourier transform infrared spectroscopy (FT-IR). Specifically, it can be measured using a Fourier transform infrared spectrophotometer (such as "UMA600" manufactured by Agilent Technologies, etc.) by total reflectance measurement (ATR method). The peak absorbance area around 1660cm ^-1 is derived. Furthermore, the "peak absorbance area of the amide acid oligomer" in the following formula means that after the compound having an acid anhydride group and the monoamine having a phenolic hydroxyl group are reacted, the imidization step is not carried out. The absorbance area of the amide acid oligomer was obtained by removing the solvent by evaporation.

Imidization rate (%)=100×(1-(peak absorbance area after imidization)/(peak absorbance area of amide acid oligomer))

As described above, when the imide oligomer of the present invention is used as a curing agent, a cured product having excellent long-term heat resistance can be obtained. The curing agent composed of the imide oligomer of the present invention is also one of the present invention. Moreover, the adhesive agent containing curable resin and the hardening agent of this invention is also one of this invention.

Regarding the content of the curing agent of the present invention in the adhesive of the present invention, the lower limit is preferably 50 parts by weight and the upper limit is 500 parts by weight relative to 100 parts by weight of the curable resin. When content of the hardening|curing agent of this invention falls into this range, the hardened|cured material of the adhesive obtained becomes one more excellent in long-term heat resistance. A more preferable lower limit of the content of the curing agent in the present invention is 70 parts by weight, and a more preferable upper limit is 400 parts by weight.

In order to improve workability in an uncured state, etc., the adhesive of the present invention may contain other curing agents in addition to the curing agent of the present invention within the range that does not interfere with the object of the present invention.

Examples of the other curing agents include phenolic curing agents, mercaptan curing agents, amine curing agents, acid anhydride curing agents, cyanate ester curing agents, and active ester curing agents. Among these, phenol-based curing agents, acid anhydride-based curing agents, cyanate-based curing agents, and active ester-based curing agents are preferred.

When the adhesive of the present invention contains the above-mentioned other curing agents, the upper limit of the ratio of the above-mentioned other curing agents in the entire curing agent is preferably 70% by weight, more preferably 50% by weight, and even more preferably 30% by weight %.

The adhesive of the present invention contains a curable resin.

From the viewpoint of the fluidity and workability of the obtained adhesive, the curable resin is preferably liquid at 25°C.

As the curable resin, an epoxy resin can be preferably used.

Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol E epoxy resin, bisphenol S epoxy resin, 2,2'-diallyl Bisphenol A type epoxy resin, hydrogenated bisphenol type epoxy resin, propylene oxide added bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, sulfide ring Oxygen resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, fennel type epoxy resin, naphthyl ether type epoxy resin, phenolic novolac type epoxy resin, o-cresol novolac epoxy resin, dicyclopentadiene novolac epoxy resin, biphenyl novolac epoxy resin, naphthol novolac epoxy resin, glycidylamine epoxy resin, alkyl polyol epoxy resin Oxygen resins, rubber-modified epoxy resins, glycidyl ester compounds, etc. Among them, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and resorcinol type epoxy resin are preferred in terms of low viscosity and easy adjustment of the processability of the obtained adhesive at room temperature. oxygen resin.

The adhesive of the present invention may also contain a hardening accelerator. By containing the above-mentioned hardening accelerator, the 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, photobase generators, and columium salt-based curing accelerators. Among these, imidazole-based hardening accelerators are preferred.

With respect to 100 parts by weight of the above-mentioned curable resin, the content of the above-mentioned hardening accelerator has a preferable lower limit of 0.01 parts by weight, and a preferable upper limit of 10 parts by weight. When the content of the above-mentioned curing accelerator is in this range, the effect of shortening the curing time is more excellent while maintaining excellent adhesiveness and the like. A more preferable lower limit of the content of the above-mentioned hardening accelerator is 0.05 parts by weight, and a more preferable upper limit is 5 parts by weight.

The adhesive agent of the present invention may also contain an organic filler for the purpose of relieving stress, imparting toughness, imparting flame retardancy, and the like.

Examples of the organic filler include silicone rubber particles, acrylic rubber particles, urethane rubber particles, polyamide particles, polyamideimide particles, polyimide particles, benzomelamine (Benzoguanamine) particles, and their core-shell (Core-shell) particles, etc. Among them, polyamide particles, polyamideimide particles, and polyimide particles are preferable.

With respect to 100 parts by weight of the curable resin above, the lower limit of the content of the organic filler is preferably 10 parts by weight, and the upper limit is preferably 500 parts by weight. When the content of the organic filler is within this range, the cured product obtained while maintaining excellent adhesiveness and the like becomes more excellent in toughness and the like. A more preferable lower limit of the content of the organic filler is 30 parts by weight, and a more preferable upper limit is 400 parts by weight.

The adhesive agent of the present invention can also contain an inorganic filler for the purpose of reducing the linear expansion coefficient after curing to reduce bending, imparting flame retardancy, or improving adhesion reliability.

Examples of the above-mentioned inorganic filler include silica such as silicic acid gel, alumina, aluminum nitride, boron nitride, silicon nitride, aluminum hydroxide, magnesium hydroxide, glass powder, glass frit, Glass fiber, carbon fiber, inorganic ion exchanger, etc.

With respect to 100 parts by weight of the curable resin, the lower limit of the content of the inorganic filler is preferably 10 parts by weight, and the upper limit is preferably 1000 parts by weight. When content of the said inorganic filler exists in this range, effects, such as improvement of adhesion reliability, are more excellent in the state which maintains excellent processability etc.. A more preferable lower limit of the content of the above-mentioned inorganic filler is 20 parts by weight, and a more preferable upper limit is 900 parts by weight.

Moreover, an inorganic filler can also be used as a flow regulator for the purpose of improving applicability to an adherend, shape retention property, etc. in a short time.

Examples of inorganic fillers used as flow regulators include fumed silica and layered silicates.

With respect to 100 parts by weight of the above-mentioned curable resin, the content of the above-mentioned inorganic filler used as a flow regulator has a preferable lower limit of 0.1 parts by weight, and a preferable upper limit of 50 parts by weight. When the content of the inorganic filler used as the above-mentioned flow regulator is in this range, effects such as improvement of applicability and shape retention in a short time to an adherend are more excellent. A more preferable lower limit of the content of the above-mentioned inorganic filler used as a flow regulator is 0.5 parts by weight, and a more preferable upper limit is 30 parts by weight.

The adhesive agent of this invention may contain a polymer compound within the range which does not interfere with the object of this invention. The above-mentioned polymer compound functions as a film-forming component.

The above polymer compound may also have a reactive functional group.

As said reactive functional group, an amine group, an urethane group, an imide group, a hydroxyl group, a carboxyl group, an epoxy group etc. are mentioned, for example.

In addition, the above polymer compound may or may not form a phase-separated structure in the cured product. When the polymer compound does not form a phase-separated structure in the cured product, it is preferable that the polymer compound has An epoxy group is a polymer compound having the above-mentioned reactive functional groups.

The adhesive agent of the present invention may also contain a reactive diluent within the range that does not interfere with the object of the present invention.

As said reactive diluent, the reactive diluent which has 2 or more reactive functional groups in 1 molecule is preferable from a viewpoint of adhesive reliability.

As a reactive functional group which the said reactive diluent has, the thing similar to the reactive functional group which the said polymer compound has is mentioned is mentioned.

The adhesive of the present invention may further contain additives such as solvents, coupling agents, dispersants, storage stabilizers, anti-bleeding agents, fluxes, and liquid flame retardants.

As a method of producing the adhesive of the present invention, for example, using a mixer such as a homogeneous disperser, a universal mixer, a Banbury mixer, or a kneader, to mix a curable resin, the curing agent of the present invention, and optionally add The method of mixing other hardeners or hardening accelerators, etc.

Moreover, the adhesive film which consists of the adhesive agent of this invention can be obtained by apply|coating the adhesive agent of this invention on a release film, and drying it.

The adhesive of the present invention can be used in a wide range of applications, especially for electronic materials that require high heat resistance. For example, it can be used as a die attach agent for electronic control units (ECUs) for aviation and vehicles, or for power devices using SiC or GaN. Also, for example, it can also be used as an adhesive for power overlay packaging, an adhesive for printed wiring boards, an adhesive for cover layers of flexible printed circuit boards, an adhesive for semiconductor bonding, and an adhesive for structural materials. Furthermore, in addition to adhesive applications, it can also be used, for example, as a curable composition for sealants, copper-clad laminates, adhesives for semiconductor joining, interlayer insulating films, prepregs, and the like.

According to the present invention, there can be provided an imide oligomer which can be used for a cured product excellent in long-term heat resistance. Also, according to the present invention, a curing agent composed of the imide oligomer and an adhesive using the curing agent can be provided. Furthermore, according to the present invention, a method for producing the imide oligomer can be provided.

Hereafter, although an Example is disclosed and this invention is demonstrated in more detail, this invention is not limited only to these Examples.

(Synthesis example 1 (production of imide oligomer A))

32.74 parts by weight of 3-aminophenol (manufactured by Tokyo Chemical Industry Co., Ltd.) (1.5 equivalents to the acid anhydride group of 3,4'-oxydiphthalic dianhydride to be reacted) was dissolved in N,N-dimethyl In 200 mL of methyl formamide. To the obtained solution, 31.0 parts by weight of 3,4'-oxydiphthalic dianhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added, stirred at 25°C for 2 hours, and reacted to obtain an amide acid oligomer solution. The obtained amide acid oligomer solution was added to 2 L of 1 mol/L hydrochloric acid, and the precipitate was recovered. The obtained precipitate was dissolved in 100 mL of N,N-dimethylformamide, the obtained solution was added to 2 L of 0.5 mol/L hydrochloric acid, and the precipitate was recovered. The obtained precipitate was dissolved in 100 mL of N,N-dimethylformamide, the obtained solution was added to 2 L of 0.1 mol/L hydrochloric acid, and the precipitate was recovered. The obtained precipitate was reacted under imidization conditions of heating at 180° C. for 2 hours and then heating at 300° C. for 2 hours to obtain an imide oligomer A (acyl imide) having a phenolic hydroxyl group. Amination rate 94%).

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer A contains the imide oligomer represented by the above-mentioned formula (1-1) as a main component. In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer A contained 5.5% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer A was 506.

(Synthesis example 2 (production of imide oligomer B))

The conditions for the imidization of the precipitate were changed to use a vacuum drying oven, and heated at 200° C. and 5 mmHg for 3 hours, except that, in the same manner as in Synthesis Example 1, an imide oligomer B (acyl) having a phenolic hydroxyl group was obtained. The imidization rate is 46%).

By ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer B contained the imide oligomer represented by the above formula (1-1). In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer B contained 5.5% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer B was 510.

(Synthesis example 3 (production of imide oligomer C))

The same as in Synthesis Example 1 except that the amount of 3-aminophenol used was changed to 65.48 parts by weight (3 equivalents to the acid anhydride group of the reacted 3,4'-oxydiphthalic dianhydride). An imide oligomer C having a phenolic hydroxyl group was successfully obtained (imidization rate 94%).

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer C contains the imide oligomer represented by the above-mentioned formula (1-1) as a main component. In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer C contained 4.7% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer C was 506.

(Synthesis example 4 (production of imide oligomer D))

Change 32.74 parts by weight of 3-aminophenol into 36.95 parts by weight of 5-amino-o-cresol (manufactured by Tokyo Chemical Industry Co., Ltd.) group is 1.5 equivalents), except that, in the same manner as in Synthesis Example 1, an imide oligomer D (imidation ratio: 94%) having a phenolic hydroxyl group was obtained.

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer D contains the imide oligomer represented by the above-mentioned formula (1-1) as a main component. Furthermore, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer D contained 5.3% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer D was 531.

(Synthesis example 5 (production of imide oligomer E))

Add 52.0 parts by weight of 4,4'-(4,4'-isopropylidene diphenoxy) diphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) instead of 3,4'-oxydiphthalic acid Except 31.0 weight part of dianhydrides, the imide oligomer E (93% of imidization rate) which has a phenolic hydroxyl group was obtained similarly to the synthesis example 1. The amount of 3-aminophenol used is 1.5 equivalents relative to the acid anhydride group of 4,4'-(4,4'-isopropylidene diphenoxy)bisphthalic anhydride to be reacted.

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer E contains the imide oligomer represented by the above-mentioned formula (1-1) as a main component. In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer E contained 5.4% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer E was 712.

(Synthesis example 6 (production of imide oligomer F))

Dissolve 34.45 parts by weight of 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene ("Bisaniline M" manufactured by MITSUI FINE CHEMICALS) in N,N-dimethylformyl Amine 200mL. 104.1 parts by weight of 4,4'-(4,4'-isopropylidene diphenoxy)diphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the obtained solution, and stirred at 25° C. for 2 hours , making it react to obtain a solution of an amide acid oligomer (A) having acid anhydride groups at both ends. Add 32.74 parts by weight of 3-aminophenol (manufactured by Tokyo Chemical Industry Co., Ltd.) to the solution of the obtained amide acid oligomer (A) 1.5 equivalents), stirred at 25°C for 2 hours, and reacted to obtain a solution of the amide acid oligomer (B). The solution of the obtained amide acid oligomer (B) was added to 2 L of 1 mol/L hydrochloric acid, and the precipitate was recovered. The obtained precipitate was dissolved in 100 mL of N,N-dimethylformamide, the obtained solution was added to 2 L of 0.5 mol/L hydrochloric acid, and the precipitate was recovered. The obtained precipitate was dissolved in 100 mL of N,N-dimethylformamide, the obtained solution was added to 2 L of 0.1 mol/L hydrochloric acid, and the precipitate was recovered. The obtained precipitate was reacted under imidization conditions of heating at 180°C for 2 hours and then heating at 300°C for 2 hours to obtain an imide oligomer F(acyl) having a phenolic hydroxyl group. The imidization rate is 92%).

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer F contains the imide oligomer represented by the above-mentioned formula (1-2) as a main component. In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer F contained 5.5% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer F was 1548.

(Synthesis example 7 (production of imide oligomer G))

Change the amount of 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene to 17.23 parts by weight, and change the amount of 3-aminophenol to 49.11 parts by weight, except Besides. An imide oligomer G having a phenolic hydroxyl group was obtained in the same manner as in Synthesis Example 6 (imide ratio: 93%). The amount of 3-aminophenol used is 1.5 equivalents relative to the acid anhydride group of the amide acid oligomer (A) undergoing the reaction.

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer G contains the imide oligomer represented by the above-mentioned formula (1-2) as a main component. Furthermore, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer G contained 5.4% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer G was 1126.

(Synthesis example 8 (production of imide oligomer H))

Dissolve 34.5 parts by weight of 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene ("Bisaniline M" manufactured by MITSUI FINE CHEMICALS) in N-methylpyrrolidone (and "NMP" manufactured by Kopure Pharmaceutical Co., Ltd.) in 200 mL. 104.1 parts by weight of 4,4'-(4,4'-isopropylidene diphenoxy)diphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the obtained solution, and stirred at 25° C. for 2 hours , making it react to obtain the amide acid oligomer solution (A). To the obtained amide acid oligomer solution (A), 32.74 parts by weight of 3-aminophenol (manufactured by Tokyo Chemical Industry Co., Ltd. 1.5 equivalents), stirred at 25° C. for 2 hours, and reacted to obtain an amide acid oligomer solution (B). The solution of the obtained amide acid oligomer (B) was added to 2 L of 1 mol/L hydrochloric acid, and the precipitate was recovered. The obtained precipitate was dissolved in 100 mL of N,N-dimethylformamide, the obtained solution was added to 2 L of 0.5 mol/L hydrochloric acid, and the precipitate was recovered. The obtained precipitate was dissolved in 100 mL of N,N-dimethylformamide, the obtained solution was added to 2 L of 0.1 mol/L hydrochloric acid, and the precipitate was recovered. The obtained precipitate was reacted under imidization conditions of heating at 180°C for 2 hours and then heating at 300°C for 2 hours to obtain an imide oligomer H(acyl) having a phenolic hydroxyl group. The imidization rate is 92%).

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer H contains the imide oligomer represented by the above-mentioned formula (1-2) as a main component. In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer H contained 5.5% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer H was 2,720.

(Synthesis example 9 (production of imide oligomer I))

Change 34.45 parts by weight of 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene to 25.83 parts by weight of 2,2-bis(3-amino-4-hydroxyphenyl)propane , except that, the imide oligomer I having a phenolic hydroxyl group was obtained in the same manner as in Synthesis Example 6 (93% imidization ratio).

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer I contains the imide oligomer represented by the above-mentioned formula (1-2) as a main component. In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the content ratio of the imide oligomer I having an ester bond was 5.4%. Furthermore, the number average molecular weight of the imide oligomer I was 1490.

(Synthesis example 10 (production of imide oligomer J))

The same as in Synthesis Example 1 except that the amount of 3-aminophenol used was changed to 21.83 parts by weight (1 equivalent to the acid anhydride group of the reacted 3,4'-oxydiphthalic dianhydride). The imide oligomer J having a phenolic hydroxyl group was successfully obtained (imidization ratio 93%).

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer J contains the imide oligomer represented by the above-mentioned formula (1-1) as a main component. In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer J contained 8.2% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer J was 543.

(Synthesis example 11 (production of imide oligomer K))

The conditions for the imidization of the precipitate were changed to use a vacuum drying oven and heated at 200° C. and 5 mmHg for 3 hours, except that the imide oligomer K was obtained in the same manner as in Synthesis Example 10 (the imidization ratio was 44 %).

By ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer K contained the imide oligomer represented by the above formula (1-1). In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer K contained 8.2% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer K was 556.

(Synthesis example 12 (production of imide oligomer L))

Except having changed the usage-amount of 3-aminophenol into 21.83 weight part, it carried out similarly to the synthesis example 6, and obtained the imide oligomer L which has a phenolic hydroxyl group (92% of imidization rate). The amount of 3-aminophenol used is 1 equivalent relative to the acid anhydride group of the amide acid oligomer (A) undergoing the reaction.

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer L contains the imide oligomer represented by the above formula (1-2) as a main component. In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer L contained 8.0% of the imide oligomer having an ester bond. Furthermore, the number average molecular weight of the imide oligomer L was 1710.

(Synthesis example 13 (production of imide oligomer M))

Except changing the usage amount of 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene to 17.23 parts by weight, the acyl group having a phenolic hydroxyl group was obtained in the same manner as in Synthesis Example 6. Imine oligomer M (imidization rate 92%). The amount of 3-aminophenol used is 1 equivalent relative to the acid anhydride group of the amide acid oligomer (A) undergoing the reaction.

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer M contains the imide oligomer represented by the above-mentioned formula (1-2) as a main component. Furthermore, by GPC fractionation and FT-IR analysis, it was confirmed that the imide oligomer M has an ester bond-containing imide oligomer content ratio of 8.1%. Furthermore, the number average molecular weight of the imide oligomer M was 1241.

(Synthesis example 14 (production of imide oligomer N))

The amount of 3-aminophenol used was changed to 21.83 parts by weight (with respect to the acid anhydride group of the amide acid oligomer (A) that was reacted was 1 equivalent), except that, in the same manner as in Synthesis Example 9, a compound having phenol was obtained. Amide imide oligomer N with neutral hydroxyl group (imidization rate 94%).

Furthermore, by ¹ H-NMR, GPC, and FT-IR analysis, it was confirmed that the imide oligomer N contains the imide oligomer represented by the above formula (1-2) as a main component. In addition, by GPC fractionation and FT-IR analysis, it was confirmed that the content ratio of the imide oligomer N having an ester bond was 8.4%. Furthermore, the number average molecular weight of the imide oligomer N was 1571.

(Examples 1-9, Comparative Examples 1-5)

According to the blending ratios recorded in Tables 1 and 2, each material was stirred and mixed to prepare the adhesives of Examples 1-9 and Comparative Examples 1-5.

<assessment>

The following evaluations were performed on each of the adhesives obtained in Examples and Comparative Examples. The results are shown in Tables 1 and 2.

(5% weight loss temperature)

An adhesive film with a thickness of 25 μm was obtained by applying and drying each adhesive agent obtained in Examples and Comparative Examples on a release film.

For the adhesive film obtained by heating the obtained adhesive film at 190°C for 1 hour to harden it, use a thermogravimetric measurement device ("EXTEAR TG/DTA6200" manufactured by SII NanoTechnology Co., Ltd.) at a temperature of 40°C to 450°C. Temperature range, 10°C/min heating condition to measure 5% weight loss temperature.

(Long-term heat resistance (adhesion))

Kapton (registered trademark) with a thickness of 50 μm in both layers of each adhesive obtained in Examples and Comparative Examples was hardened by heating at 190° C. for 1 hour, followed by cutting out short strips with a width of 1 cm. Get test strips. The obtained test piece was heat-treated at 175° C. for 1000 hours. For the test piece after the heat treatment, the adhesive strength was measured at a peeling speed of 20 mm/min using a tensile tester ("UCT-500" manufactured by ORIENTEC).

The case where the adhesive force was 3.4 N/cm or more was set as "○", the case of less than 3.4 N/cm and more than 2.4 N/cm was set as "△", and the case of less than 2.4 N/cm was set as "△". "×" was used to evaluate the long-term heat resistance.

Industrial availability

According to the present invention, there can be provided an imide oligomer which can be used for a cured product excellent in long-term heat resistance. Also, according to the present invention, a curing agent composed of the imide oligomer and an adhesive using the curing agent can be provided. Furthermore, according to the present invention, a method for producing the imide oligomer can be provided.

Claims (5)

An imide oligomer having a phenolic hydroxyl group, characterized in that it contains an imide oligomer represented by the following formula (1-1) and/or the following formula (1-2) as a main component ,

In formulas (1-1) and (1-2), R ¹ and R ² are independently a hydrogen atom, a halogen atom, or a valent hydrocarbon group that can be substituted, and X is a bond, an oxygen atom, or a Substituted divalent hydrocarbon groups, in formula (1-2), Y is a bond, an oxygen atom, or a divalent hydrocarbon group that can be substituted, and the proportion of imide oligomers with ester bonds is less than 7%. And the imidization rate is over 70%. The number average molecular weight of the imide oligomer according to claim 1 is 400 or more and 4200 or less. A hardening agent composed of the imide oligomer described in claim 1 or 2. An adhesive containing curable resin and the curing agent described in claim 3. A method for producing an imide oligomer, which is the method for producing an imide oligomer described in claim 1 or 2, comprising reacting a compound having an acid anhydride group with a monoamine having a phenolic hydroxyl group The step of obtaining the amide acid oligomer solution, and the step of adding the obtained amide acid oligomer solution to the acid and recovering the precipitate; and the amount of the above-mentioned monoamine with phenolic hydroxyl group is relatively The acid anhydride group in the above-mentioned compound having an acid anhydride group is 1.5 equivalents or more.