WO2023136098A1

WO2023136098A1 - Curable resin composition, cured product, adhesive agent, and adhesive film

Info

Publication number: WO2023136098A1
Application number: PCT/JP2022/047610
Authority: WO
Inventors: 健太郎北條; さやか脇岡; 悠中村
Original assignee: 積水化学工業株式会社
Priority date: 2022-01-12
Filing date: 2022-12-23
Publication date: 2023-07-20
Also published as: TW202334346A

Abstract

One purpose of the present invention is to provide a curable resin composition from which a cured product having high reliability can be obtained. Another purpose of the present invention is to provide a cured product of the aforesaid curable resin composition, as well as an adhesive agent and an adhesive film obtained by using the curable resin composition. The present invention relates to a curable resin composition that contains a curable resin and a curing agent, said curing agent having a structure derived from a diamine represented by formula (1), wherein, when a cured product thereof is subjected to a temperature cycling test under the conditions of -55°C to 150°C and 1000 cycles, the change rate of storage modulus of the cured product at 25°C before and after the temperature cycling test is 25% or less, and the change rate of storage modulus of the cured product at 150°C before and after the temperature cycling test is 250% or less.

Description

Curable resin composition, cured product, adhesive and adhesive film

The present invention relates to a curable resin composition. The present invention also relates to a cured product of the curable resin composition, and an adhesive and an adhesive film using the curable resin composition.

In recent years, the use of flexible printed circuit boards (FPCs) has expanded to include vehicle-mounted applications, and adhesives used for FPCs and coverlay films that protect FPCs are required to have heat resistance at high temperatures. For such adhesives, curable resin compositions using curable resins such as epoxy resins, which have low shrinkage and excellent adhesiveness, insulation, and chemical resistance, are used. There is a demand for a curable resin composition that gives good results in a solder reflow test and a long-term heat resistance test related to long-term heat resistance. As a curable resin composition excellent in heat resistance and adhesiveness, for example, Patent Documents 1 and 2 disclose a curable resin composition containing an epoxy resin and an imide compound as a curing agent.

JP-A-61-270852 Japanese Patent Publication No. 2004-502859

Conventional curable resin compositions, even if they are excellent in short-term heat resistance and long-term heat resistance, are inferior in reliability, such as cracks occurring when the cured product is subjected to a temperature cycle test (TCT). It happened to be.
An object of the present invention is to provide a curable resin composition from which a highly reliable cured product can be obtained. 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.

The present disclosure 1 contains a curable resin and a curing agent, the curing agent has a structure derived from a diamine represented by the following formula (1), the cured product is -55 ° C. to 150 ° C., 1000 When a temperature cycle test is performed under cycle conditions, the rate of change in the storage elastic modulus of the cured product at 25 ° C. before and after the temperature cycle test is 25% or less, and the cured product at 150 ° C. before and after the temperature cycle test. A curable resin composition having a storage elastic modulus change rate of 250% or less.
In the present disclosure 2, the cured product before the temperature cycle test has a storage elastic modulus at 25 ° C. of 2.8 GPa or more, and the cured product before the temperature cycle test has a storage elastic modulus of 1.3 GPa or more at 150 ° C. It is a curable resin composition of the present disclosure 1.
Present Disclosure 3 is the curable resin composition of Present Disclosure 1 or 2, wherein the amount of change in the glass transition temperature of the cured product before and after the temperature cycle test is 15° C. or less.
The present disclosure 4 is the curable resin composition of the present disclosure 1, 2 or 3, wherein the curable resin contains an epoxy resin.
Present Disclosure 5 is the curable resin composition of Present Disclosure 1, 2, 3, or 4, wherein the curing agent includes an imide oligomer having a structure derived from the diamine represented by formula (1).
The present disclosure 6 is a cured product of the curable resin composition of the present disclosure 1, 2, 3, 4 or 5.
The present disclosure 7 is an adhesive using the curable resin composition of the present disclosure 1, 2, 3, 4 or 5.
Disclosure 8 is an adhesive film using the adhesive of Disclosure 7.

The present invention will be described in detail below.
The present inventors used a curable resin composition having a specific structure as a curing agent, and stored the cured product at 25 ° C. before and after the temperature cycle test under the conditions of -55 ° C. to 150 ° C. and 1000 cycles. A study was made to make the rate of change in elastic modulus and the rate of change in storage elastic modulus at 150° C. of the cured product before and after the temperature cycle test each less than a specific value. As a result, the inventors have found that the resulting curable resin composition can provide a highly reliable cured product, and have completed the present invention.

The curable resin composition of the present invention is subjected to a temperature cycle test under the conditions of -55 ° C. to 150 ° C. and 1000 cycles for the cured product, and the change in storage elastic modulus at 25 ° C. of the cured product before and after the temperature cycle test. rate is 25% or less. In addition, the curable resin composition of the present invention has a storage elastic modulus change rate of 250% or less at 150° C. of the cured product before and after the temperature cycle test. The rate of change in the storage elastic modulus of the cured product at 25°C before and after the temperature cycle test is 25% or less, and the rate of change in the storage elastic modulus of the cured product at 150°C before and after the temperature cycle test is 250% or less. As a result, the curable resin composition of the present invention can provide a highly reliable cured product. The rate of change in the storage elastic modulus of the cured product at 25° C. before and after the temperature cycle test is preferably 22% or less, more preferably 18% or less. Moreover, the rate of change in the storage elastic modulus of the cured product at 150° C. before and after the temperature cycle test is preferably 240% or less, more preferably 220% or less. Most preferably, the rate of change in storage elastic modulus at 25° C. of the cured product before and after the temperature cycle test and the rate of change in storage elastic modulus at 150° C. of the cured product before and after the temperature cycle test are most preferably 0%.
In the present specification, the "change rate of the storage elastic modulus of the cured product at 25 ° C. before and after the temperature cycle test" is 100 × ((storage elastic modulus of the cured product at 25 ° C. after the temperature cycle test) - ( It is a value represented by (storage modulus at 25° C. of cured product before temperature cycle test))/(storage modulus at 25° C. of cured product before temperature cycle test). Further, in the present specification, the above-mentioned "change rate of the storage elastic modulus of the cured product at 150 ° C. before and after the temperature cycle test" is 100 × ((storage elastic modulus of the cured product at 150 ° C. after the temperature cycle test) - ( It is a value represented by (storage elastic modulus at 150° C. of cured product before temperature cycle test))/(storage elastic modulus at 150° C. of cured product before temperature cycle test).
In the temperature cycle test, after holding at -55 ° C. for 16 minutes, the temperature was raised to 150 ° C. over 15 minutes, held at 150 ° C. for 16 minutes, and then the temperature was lowered to -55 ° C. over 15 minutes. 1000 cycles are performed as one cycle.
The storage elastic modulus can be measured using a dynamic viscoelasticity measuring device under the conditions of strain amplitude of 10 μm, measurement frequency of 10 Hz, and temperature increase rate of 10° C./min. Examples of the dynamic viscoelasticity measuring device include EXSTAR6000 (manufactured by SII).
The cured product for measuring the storage elastic modulus is a curable resin composition film having a thickness of about 15 μm obtained by coating the curable resin composition on the base film and then drying it to a thickness of about 300 μm. It can be obtained by stacking layers so as to form a layer, cutting out a piece having a width of 3 mm and a length of 5 cm, and heating it at 190° C. for 1 hour.

The curable resin composition of the present invention has a storage elastic modulus of 2.8 GPa or more at 25 ° C. of the cured product before the temperature cycle test, and a storage elastic modulus at 150 ° C. of the cured product before the temperature cycle test. is preferably 1.3 GPa or more. The cured product before the temperature cycle test has a storage elastic modulus of 2.8 GPa or more at 25°C, and the cured product has a storage elastic modulus of 1.3 GPa or more at 150°C before the temperature cycle test, The curable resin composition of the present invention can provide a cured product with excellent reliability. The storage elastic modulus at 25° C. of the cured product before the temperature cycle test is more preferably 2.9 GPa or more, further preferably 3.0 GPa or more. Moreover, the storage elastic modulus at 150° C. of the cured product before the temperature cycle test is more preferably 1.4 GPa or more, and even more preferably 1.5 GPa or more. Although there is no particular upper limit for the storage elastic modulus, the practical upper limit is 10 GPa at both 25°C and 150°C.

The curable resin composition of the present invention preferably has a glass transition temperature change of 15° C. or less before and after the temperature cycle test. When the amount of change in the glass transition temperature of the cured product before and after the temperature cycle test is 15° C. or less, the curable resin composition of the present invention makes it possible to obtain a cured product with excellent reliability. The amount of change in the glass transition temperature of the cured product before and after the temperature cycle test is preferably 14° C. or less, more preferably 12° C. or less.
In this specification, the above "change in glass transition temperature of the cured product before and after the temperature cycle test" is (glass transition temperature of the cured product after the temperature cycle test) - (glass of the cured product before the temperature cycle test) transition temperature).
As used herein, the term “glass transition temperature” means the temperature at which the maximum loss tangent (tan δ) obtained by dynamic viscoelasticity measurement appears due to micro-Brownian motion. Specifically, using a dynamic viscoelasticity measuring device, the tan δ curve obtained when measured in a temperature range from 25 ° C. to 250 ° C. under the conditions of a strain amplitude of 10 μm, a measurement frequency of 10 Hz, and a temperature increase rate of 10 ° C./min. It can be obtained as a peak temperature. Examples of the dynamic viscoelasticity measuring device include EXSTAR6000 (manufactured by SII).
The cured product for measuring the glass transition temperature is a curable resin composition film having a thickness of about 15 μm obtained by coating the curable resin composition on the base film and then drying it to a thickness of about 300 μm. It can be obtained by stacking layers so as to form a layer, cutting out a piece having a width of 3 mm and a length of 5 cm, and heating it at 190° C. for 1 hour.

In the curable resin composition of the present invention, the preferable lower limit of the glass transition temperature of the cured product is 173°C. When the glass transition temperature of the cured product is 173° C. or higher, the cured product of the curable resin composition of the present invention is excellent in mechanical strength and high-temperature long-term heat resistance. A more preferable lower limit of the glass transition temperature of the cured product is 175°C.
Although there is no particular upper limit for the glass transition temperature of the cured product, the practical upper limit is 230°C.

The curable resin composition of the present invention contains a curable resin.
Examples of the curable resins include epoxy resins, acrylic resins, phenol resins, cyanate resins, isocyanate resins, maleimide resins, benzoxazine resins, silicone resins, and fluororesins. Especially, it is preferable that the said curable resin contains an epoxy resin. These curable resins may be used alone, or two or more of them may be used in combination.
In addition, the curable resin is preferably liquid or semi-solid at 25 ° C. in order to improve tackiness at room temperature and processability such as film processing, and is liquid at 25 ° C. More preferably, it contains an epoxy resin that is liquid at 25°C.

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'-diallylbisphenol A type epoxy resin, and hydrogenated bisphenol type epoxy resin. , propylene oxide-added bisphenol A type epoxy resin, triazine 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 Resin, naphthylene ether type epoxy resin, phenol novolac type epoxy resin, ortho-cresol novolak type epoxy resin, dicyclopentadiene novolak type epoxy resin, biphenyl novolak type epoxy resin, naphthalenephenol novolak type epoxy resin, glycidylamine type epoxy resin, alkyl Polyol-type epoxy resins, rubber-modified epoxy resins, glycidyl ester compounds, and the like can be mentioned. Among them, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, resorcinol type epoxy resin, and triazine are preferred because they have a low viscosity and make it easier to adjust the processability of the resulting curable resin composition. type epoxy resins are preferred.

The curable resin composition of the present invention contains a curing agent.
The curing agent has a structure derived from the diamine represented by formula (1). Hereinafter, the curing agent having a structure derived from the diamine represented by the above formula (1) is also referred to as "curing agent according to the present invention". By containing the curing agent according to the present invention, the curable resin composition of the present invention has a rate of change in storage elastic modulus at 25 ° C. of the cured product before and after the temperature cycle test, and a cured product before and after the temperature cycle test. It becomes easy to make the rate of change of the storage elastic modulus at 150° C. equal to or less than the values described above.

From the viewpoint of the initial adhesiveness of the cured product of the curable resin composition obtained, the adhesiveness after the temperature cycle test, and the long-term heat resistance, the curing agent according to the present invention is the above formula (1) It preferably contains an imide oligomer having a structure derived from a diamine represented by.

The imide oligomer preferably has an acid anhydride group or a phenolic hydroxyl group at the end of the main chain, and more preferably has an acid anhydride group or a phenolic hydroxyl group at both ends of the main chain.

The imide oligomer preferably has a structure represented by formula (2-1) or formula (2-2) below. By having the structure represented by the following formula (2-1) or the following formula (2-2), the imide oligomer is superior in reactivity and compatibility with the curable resin.

In formulas (2-1) and (2-2), A is an acid dianhydride residue, B is a divalent group represented by the following formula (3), and formula (2- In 2), Ar is an optionally substituted divalent aromatic group.

In formula (3), * is a binding position.

The acid dianhydride residue is preferably a tetravalent group represented by the following formula (4-1) or the following formula (4-2).

In formulas (4-1) and (4-2), * is a bonding position, and in formula (4-1), Z is a bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, a straight It is a chain or branched divalent hydrocarbon group or a divalent group having an aromatic ring. When Z is a hydrocarbon group, it may have an oxygen atom between the hydrocarbon group and each aromatic ring in formula (4-1), Z is a divalent group having an aromatic ring In some cases, an oxygen atom may be present between the divalent group having the aromatic ring and each aromatic ring in formula (4-1). The hydrogen atoms of the aromatic rings in formulas (4-1) and (4-2) may be substituted.

When Z in the above formula (4-1) is a linear or branched divalent hydrocarbon group or a divalent group having an aromatic ring, these groups are substituted good too.
Examples of substituents in the case where the linear or branched divalent hydrocarbon group or the divalent group having an aromatic ring is substituted include, for example, a halogen atom, a linear or branched chain linear alkyl groups, linear or branched alkenyl groups, alicyclic groups, aryl groups, alkoxy groups, nitro groups, cyano groups and the like.

Examples of acid dianhydrides from which the acid dianhydride residue is derived include acid dianhydrides represented by formula (8) described later.

In addition, if the imide oligomer has a siloxane skeleton in its structure, it may lower the glass transition temperature after curing and may contaminate the adherend and cause adhesion failure. imide oligomers are preferred.

The imide oligomer preferably has a number average molecular weight of 5,000 or less. When the imide oligomer has a number average molecular weight of 5,000 or less, the resulting cured product of the curable resin composition is excellent in long-term heat resistance. A more preferable upper limit of the number average molecular weight of the imide oligomer is 4,000, and a more preferable upper limit is 3,000.
In particular, the number average molecular weight of the imide oligomer is preferably 900 or more and 5000 or less when it has the structure represented by the formula (2-1), and the structure represented by the formula (2-2) is When it has, it is preferably 550 or more and 4000 or less. A more preferable lower limit of the number average molecular weight in the case of having the structure represented by the above formula (2-1) is 950, and a more preferable lower limit is 1,000. A more preferred lower limit of the number average molecular weight is 580, and a more preferred lower limit is 600, in the case of having the structure represented by the above formula (2-2).
In addition, the above-mentioned "number average molecular weight" in this specification is a value measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent and calculated by polystyrene conversion. Examples of the column used for measuring the polystyrene-equivalent number-average molecular weight by GPC include JAIGEL-2H-A (manufactured by Japan Analytical Industry Co., Ltd.).

Specifically, the imide oligomer is represented by the following formula (5-1), the following formula (5-2), the following formula (5-3), or the following formula (5-4). Alternatively, it is preferably an imide oligomer represented by the following formula (6-1), (6-2), (6-3) or (6-4) below.

In formulas (5-1) to (5-4), A is the acid dianhydride residue, and in formulas (5-1), (5-3), and (5-4), A is They may be the same or different. In formulas (5-1) to (5-4), B is a divalent group represented by formula (3) above. In formula (5-2), X is a hydrogen atom, a halogen atom, or an optionally substituted monovalent hydrocarbon group, and in formula (5-4), W is a hydrogen atom, a halogen atom , or an optionally substituted monovalent hydrocarbon group. In formulas (5-3) and (5-4), n is the number of repetitions.

In formulas (6-1) to (6-4), A is the acid dianhydride residue, and in formulas (6-1) to (6-4), A is the same. may be different. In formulas (6-1) to (6-4), B is a divalent group represented by the above formula (3), and R is a hydrogen atom, a halogen atom, or optionally substituted It is a monovalent hydrocarbon group, and in formulas (6-1) and (6-3), R may be the same or different. In formulas (6-2) and (6-4), W is a hydrogen atom, a halogen atom, or an optionally substituted monovalent hydrocarbon group.

A in the above formulas (5-1) to (5-4) and the above formulas (6-1) to (6-4) is the following formula (7-1) or the following formula (7-2) It is preferably a tetravalent group represented.

In formulas (7-1) and (7-2), * is a bonding position, and in formula (7-1), Z is a bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, a direct It is a chain or branched divalent hydrocarbon group or a divalent group having an aromatic ring. When Z is a hydrocarbon group, it may have an oxygen atom between the hydrocarbon group and each aromatic ring in formula (7-1), Z is a divalent group having an aromatic ring In some cases, an oxygen atom may be present between the divalent group having an aromatic ring and each aromatic ring in formula (7-1). The hydrogen atoms of the aromatic rings in formulas (7-1) and (7-2) may be substituted.

As a method for producing an imide oligomer having a structure represented by the above formula (2-1), for example, an acid dianhydride represented by the following formula (8) and a diamine represented by the above formula (1) and the like.

In formula (8), A is the same tetravalent group as A in formula (2-1) above.

A specific example of the method for reacting the acid dianhydride represented by the above formula (8) with the diamine represented by the above formula (1) is shown below.
First, the diamine represented by the above formula (1) is dissolved in advance in a solvent (for example, N-methylpyrrolidone) in which the amic acid oligomer obtained by the reaction is soluble, and the resulting solution is added with the above formula (8). An acid dianhydride represented by is added and reacted to obtain an amic acid oligomer solution. Next, the solvent is removed by heating, pressure reduction, or the like, and the mixture is heated at about 200° C. or higher for 1 hour or longer to react the amic acid oligomer. By adjusting the molar ratio of the acid dianhydride represented by the above formula (8) and the diamine represented by the above formula (1), and the imidization conditions, it has a desired number average molecular weight, and both An imide oligomer having a structure represented by the above formula (2-1) at the end can be obtained.
Further, by replacing a part of the acid dianhydride represented by the above formula (8) with the acid anhydride represented by the following formula (9), it has a desired number average molecular weight and one end has the above An imide oligomer having a structure represented by the formula (2-1) and having a structure derived from an acid anhydride represented by the following formula (9) at the other end can be obtained. In this case, the acid dianhydride represented by the above formula (8) and the acid anhydride represented by the following formula (9) may be added simultaneously or separately.
Furthermore, by replacing a part of the diamine represented by the above formula (1) with a monoamine represented by the following formula (10), it has a desired number average molecular weight, and one end has the above formula (2-1) ) and having at the other end a structure derived from a monoamine represented by the following formula (10). In this case, the diamine represented by the above formula (1) and the monoamine represented by the following formula (10) may be added simultaneously or separately.

In formula (9), Ar is an optionally substituted divalent aromatic group.

In formula (10), Ar is an optionally substituted monovalent aromatic group, and R ¹ and R ² are each independently a hydrogen atom or a monovalent hydrocarbon group.

As a method for producing an imide oligomer having a structure represented by the above formula (2-2), for example, an acid dianhydride represented by the above formula (8) and a diamine represented by the above formula (1) Examples thereof include a method of reacting with a phenolic hydroxyl group-containing monoamine represented by the following formula (11).

In formula (11), Ar is an optionally substituted divalent aromatic group, and R ³ and R ⁴ are each independently a hydrogen atom or a monovalent hydrocarbon group.

Specific examples of the method for reacting the acid dianhydride represented by the above formula (8), the diamine represented by the above formula (1), and the phenolic hydroxyl group-containing monoamine represented by the above formula (11) are shown below. show.
First, a phenolic hydroxyl group-containing monoamine represented by the above formula (11) and a diamine represented by the above formula (1) are mixed in advance with a solvent in which the amic acid oligomer obtained by the reaction is soluble (for example, N-methylpyrrolidone, etc.) ), and the acid dianhydride represented by the above formula (8) is added to the obtained solution and reacted to obtain an amic acid oligomer solution. Next, the solvent is removed by heating, pressure reduction, or the like, and the mixture is heated at about 200° C. or higher for 1 hour or longer to react the amic acid oligomer. The molar ratio of the acid dianhydride represented by the above formula (8), the diamine represented by the above formula (1) and the phenolic hydroxyl group-containing monoamine represented by the above formula (11), and the imidization conditions By adjusting, it is possible to obtain an imide oligomer having a desired number average molecular weight and a structure represented by the above formula (2-2) at both ends.
Further, by replacing part of the phenolic hydroxyl group-containing monoamine represented by the above formula (11) with the monoamine represented by the above formula (10), it has a desired number average molecular weight, and one end has the above formula An imide oligomer having a structure represented by (2-2) and having a structure derived from a monoamine represented by the above formula (10) at the other end can be obtained. In this case, the phenolic hydroxyl group-containing monoamine represented by the above formula (11) and the monoamine represented by the above formula (10) may be added simultaneously or separately.

Specific examples of the acid dianhydride represented by the above formula (8) include pyromellitic anhydride, 3,3′-oxydiphthalic anhydride, 3,4′-oxydiphthalic anhydride, 4, 4'-oxydiphthalic anhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 4,4'-bis(2,3-dicarboxylphenoxy)diphenyl ether acid dianhydride , p-phenylenebis(trimellitate anhydride), 2,3,3′,4′-biphenyltetracarboxylic dianhydride and the like.
Among them, the acid dianhydride is preferably an aromatic acid dianhydride having a melting point of 240° C. or less, and an aromatic acid having a melting point of 220° C. or less, because it has excellent solubility and heat resistance. A dianhydride is more preferred, and an aromatic acid dianhydride having a melting point of 200° C. or less is even more preferred. -isopropylidenediphenoxy)diphthalic anhydride (melting point 190° C.) is particularly preferred.
In this specification, the "melting point" means a value measured as an endothermic peak temperature when the temperature is raised at 10°C/min using a differential scanning calorimeter. Examples of the differential scanning calorimeter include EXTEAR DSC6100 (manufactured by SII Nano Technology Co., Ltd.).

Examples of the acid anhydride represented by the formula (9) include phthalic anhydride, 3-methylphthalic anhydride, 4-methylphthalic anhydride, 1,2-naphthalic anhydride, and 2,3-naphthalic anhydride. acid anhydride, 1,8-naphthalic anhydride, 2,3-anthracenedicarboxylic anhydride, 4-tert-butyl phthalic anhydride, 4-ethynyl phthalic anhydride, 4-phenylethynyl phthalic anhydride, 4-fluorophthalic anhydride, 4-chlorophthalic anhydride, 4-bromophthalic anhydride, 3,4-dichlorophthalic anhydride and the like.

Monoamines represented by the above formula (10) include, for example, aniline, o-toluidine, m-toluidine, p-toluidine, 2,4-dimethylaniline, 3,4-dimethylaniline, 3,5-dimethylaniline, 2-tert-butylaniline, 3-tert-butylaniline, 4-tert-butylaniline, 1-naphthylamine, 2-naphthylamine, 1-aminoanthracene, 2-aminoanthracene, 9-aminoanthracene, 1-aminopyrene, 3- Chloroaniline, o-anisidine, m-anisidine, p-anisidine, 1-amino-2-methylnaphthalene, 2,3-dimethylaniline, 2,4-dimethylaniline, 2,5-dimethylaniline, 3,4-dimethyl aniline, 4-ethylaniline, 4-ethynylaniline, 4-isopropylaniline, 4-(methylthio)aniline, N,N-dimethyl-1,4-phenylenediamine and the like.

Examples of the phenolic hydroxyl group-containing monoamine represented by the above formula (11) 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, 4-amino-o-cresol and 5-amino-o-cresol are preferred because they are excellent in availability and storage stability and provide a high glass transition temperature after curing.

When the imide oligomer is produced by the production method described above, the imide oligomer is a plurality of imide oligomers having a structure represented by the above formula (2-1) or a structure represented by the above formula (2-2). and a mixture of each raw material (imide oligomer composition). When the imide oligomer composition has an imidization rate of 70% or more, it can provide a cured product having excellent mechanical strength at high temperatures and long-term heat resistance when used as a curing agent.
A preferable lower limit of the imidization rate of the imide oligomer composition is 75%, and a more preferable lower limit is 80%. Although there is no particular upper limit for the imidization rate of the imide oligomer composition, the practical upper limit is 98%.
The above-mentioned "imidation rate" is measured by a total reflection measurement method (ATR method) using a Fourier transform infrared spectrophotometer (FT-IR), and is derived from the carbonyl group of amic acid at 1660 cm ^-1 It can be derived from the peak absorbance area in the vicinity by the following formula. Examples of the Fourier transform infrared spectrophotometer include UMA600 (manufactured by Agilent Technologies). In addition, the "peak absorbance area of the amic acid oligomer" in the following formula is obtained by removing the solvent by evaporation or the like without performing the imidization step after reacting the acid dianhydride with the diamine or the phenolic hydroxyl group-containing monoamine. is the absorbance area of the amic acid oligomer obtained by
Imidation rate (%) = 100 × (1-(peak absorbance area after imidization)/(peak absorbance area of amic acid oligomer))

From the viewpoint of solubility in the curable resin composition, it is preferable that 3 g or more of the imide oligomer composition dissolve in 10 g of tetrahydrofuran at 25°C.

The preferable lower limit of the content of the imide oligomer in the total 100 parts by weight of the curable resin and the curing agent (further curing accelerator when containing a curing accelerator described later) is 20 parts by weight, and the preferable upper limit is 80. weight part. When the content of the imide oligomer is within this range, the resulting curable resin composition is superior in flexibility and workability before curing and heat resistance after curing. A more preferable lower limit to the content of the imide oligomer is 25 parts by weight, and a more preferable upper limit is 75 parts by weight.
In addition, when the imide oligomer is contained in the imide oligomer composition described above, the content of the imide oligomer is the same as the imide oligomer composition (and the imide oligomer composition when other imide oligomers are used in combination). (total with other imide oligomers).
A preferable lower limit of the content ratio of the structure derived from the diamine represented by the formula (1) in the imide oligomer composition is 2% by weight, and a preferable upper limit is 80% by weight. When the content ratio of the structure derived from the diamine represented by the above formula (1) is within this range, the curable resin composition of the present invention can provide a cured product with excellent reliability. A more preferred lower limit to the content of the structure derived from the diamine represented by formula (1) in the imide oligomer composition is 5% by weight, and a more preferred upper limit is 50% by weight.

The curable resin composition of the present invention preferably contains a curing accelerator. By containing the curing accelerator, the curing time can be shortened and the 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, sulfonium salt-based curing accelerators, and the like. . Of these, imidazole-based curing accelerators are preferred because of their excellent storage stability.

The content of the curing accelerator has a preferable lower limit of 0.01 parts by weight and a preferable upper limit of 10 parts by weight based on a total of 100 parts by weight of the curable resin, the curing agent and the curing accelerator. When the content of the curing accelerator is within this range, the effect of shortening the curing time while maintaining excellent adhesiveness and the like is enhanced. A more preferred lower limit to the content of the curing accelerator is 0.05 parts by weight, and a more preferred upper limit is 5 parts by weight.

The curable resin composition of the present invention may contain an inorganic filler.
The inorganic filler preferably contains at least one selected from the group consisting of silica and barium sulfate. By containing at least one selected from the group consisting of silica and barium sulfate as the inorganic filler, the curable resin composition of the present invention is superior in reflow resistance, plating resistance, and workability. Become.

Examples of inorganic fillers other than silica and barium sulfate include alumina, aluminum nitride, boron nitride, silicon nitride, magnesium carbonate, barium carbonate, glass powder, glass frit, glass fiber, carbon fiber, and inorganic ion exchange. A body etc. are mentioned.
The above inorganic fillers may be used alone, or two or more of them may be used in combination.

A preferable lower limit of the average particle size of the inorganic filler is 50 nm, and a preferable upper limit thereof is 4 μm. When the average particle size of the inorganic filler is within this range, the resulting curable resin composition is superior in coatability and workability. A more preferable lower limit of the average particle size of the inorganic filler is 100 nm, and a more preferable upper limit thereof is 3 μm.

The content of the inorganic filler has a preferable upper limit of 200 parts by weight with respect to a total of 100 parts by weight of the curable resin and the curing agent (and the curing accelerator when the curing accelerator is contained). be. When the content of the inorganic filler is within this range, the obtained cured product of the curable resin composition is excellent in reflow resistance and plating resistance while maintaining excellent tackiness and the like. A more preferable upper limit of the content of the inorganic filler is 150 parts by weight.

The curable resin composition of the present invention preferably contains a fluidity modifier for the purpose of improving wettability to an adherend in a short time and shape retention.
Examples of the flow control agent include fumed silica such as Aerosil and layered silicate.
The flow modifiers may be used alone, or two or more of them may be used in combination.
Moreover, as the fluidity control agent, one having an average particle size of less than 100 nm is preferably used.

The preferable lower limit of the content of the flow control agent is 0.1 weight part with respect to a total of 100 parts by weight of the curable resin and the curing agent (and the curing accelerator when the curing accelerator is contained). parts, and the preferred upper limit is 50 parts by weight. When the content of the flow control agent is within this range, the effect of improving the wettability to the adherend in a short time and the shape retention property, etc., is excellent. A more preferable lower limit of the content of the flow control agent is 0.5 parts by weight, and a more preferable upper limit thereof is 30 parts by weight.

The curable resin composition of the present invention 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. Among them, polyamide particles, polyamideimide particles, and polyimide particles are preferred.
The above organic fillers may be used alone, or two or more of them may be used in combination.

The preferred upper limit of the content of the organic filler is 300 parts by weight with respect to a total of 100 parts by weight of the curable resin and the curing agent (and the curing accelerator when the curing accelerator is contained). be. When the content of the organic filler is within this range, the resulting cured product of the curable resin composition is superior in toughness and the like while maintaining excellent adhesiveness and the like. A more preferable upper limit of the content of the organic filler is 200 parts by weight.

The curable resin composition of the invention may contain a polymer component. The polymer component serves as a film-forming component, and the use of the polymer component makes the cured product of the curable resin composition of the present invention more excellent in heat resistance.

A preferable lower limit of the number average molecular weight of the polymer component is 3,000, and a preferable upper limit thereof is 100,000. When the number average molecular weight of the polymer component is within this range, the resulting curable resin composition will be more excellent in heat resistance of the cured product. A more preferable lower limit of the number average molecular weight of the polymer component is 5,000, and a more preferable upper limit thereof is 80,000.

Examples of the polymer component include polyimide, phenoxy resin, polyamide, polyamideimide, polymaleimide, cyanate resin, benzoxazine resin, acrylic resin, urethane resin, and polyester resin. Among them, from the viewpoint of heat resistance, it preferably contains at least one selected from the group consisting of a polyimide resin, a polyamide resin, a polyamideimide resin, and a polymaleimide resin, and more preferably contains a polyimide resin.
The above polymer components may be used alone, or two or more may be used in combination.

The preferable lower limit of the content of the polymer component is 0.5 parts by weight with respect to a total of 100 parts by weight of the curable resin and the curing agent (and the curing accelerator when the curing accelerator is contained). , the preferred upper limit is 20 parts by weight. When the content of the polymer component is within this range, the resulting curable resin composition will be more excellent in the heat resistance of the cured product. A more preferable lower limit for the content of the polymer component is 1 part by weight, and a more preferable upper limit is 15 parts by weight.

The curable resin composition of the invention may contain a flame retardant.
Examples of the flame retardant include boehmite-type aluminum hydroxide, aluminum hydroxide, metal hydrates such as magnesium hydroxide, halogen-based compounds, phosphorus-based compounds, and nitrogen compounds. Among them, boehmite-type aluminum hydroxide is preferable.
The flame retardants may be used alone, or two or more of them may be used in combination.

The content of the flame retardant is preferably 200 parts by weight with respect to a total of 100 parts by weight of the curable resin and the curing agent (and the curing accelerator when the curing accelerator is contained). . When the content of the flame retardant is within this range, the resulting curable resin composition has excellent flame retardancy while maintaining excellent adhesion and the like. A more preferable upper limit of the content of the flame retardant is 150 parts by weight.

The curable resin composition of the present invention may contain a solvent from the viewpoint of coatability and the like.
As the solvent, a solvent having a boiling point of less than 200° C. is preferable from the viewpoint of coatability, storage stability, and the like.
Examples of the solvent having a boiling point of less than 200° C. include alcohol-based solvents, ketone-based solvents, ester-based solvents, hydrocarbon-based solvents, halogen-based solvents, ether-based solvents, and nitrogen-containing solvents.
Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, normal propyl alcohol, isobutyl alcohol, normal butyl alcohol, tertiary butyl alcohol, and 2-ethylhexanol.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl propyl ketone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, and diacetone alcohol.
Examples of the ester solvent include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, methoxybutyl acetate, amyl acetate, normal propyl acetate, isopropyl acetate, methyl lactate, ethyl lactate, and butyl lactate.
Examples of the hydrocarbon solvent include benzene, toluene, xylene, normal hexane, isohexane, cyclohexane, methylcyclohexane, ethylcyclohexane, isooctane, normal decane, normal heptane and the like.
Examples of the halogen-based solvent include dichloromethane, chloroform, and trichlorethylene.
Examples of the ether solvent include diethyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, diisopropyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate. , propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, ethylene glycol monotertiary butyl ether, propylene glycol monomethyl ether propionate, 3-methoxybutanol, diethylene glycol dimethyl ether, anisole, 4-methylanisole and the like. be done.
Examples of the nitrogen-containing solvent include acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide and the like.
Among them, from the viewpoint of handleability and solubility of imide oligomers, ketone solvents with a boiling point of 60 ° C. or higher and lower than 200 ° C., ester solvents with a boiling point of 60 ° C. or higher and lower than 200 ° C., and boiling points of 60 ° C. or higher and 200 ° C. At least one selected from the group consisting of ether-based solvents having a temperature of less than °C is preferred. Examples of such solvents include methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, isobutyl acetate, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, cyclohexanone, methylcyclohexanone, diethylene glycol dimethyl ether, and anisole.
The "boiling point" means a value measured under conditions of 101 kPa, or a value converted to 101 kPa using a boiling point conversion chart or the like.

A preferable lower limit of the content of the solvent in 100 parts by weight of the curable resin composition containing the solvent is 20 parts by weight, and a preferable upper limit thereof is 90 parts by weight. When the content of the solvent is within this range, the resulting curable resin composition is more excellent in coatability and the like. A more preferable lower limit for the content of the solvent is 30 parts by weight, and a more preferable upper limit is 80 parts by weight.

The curable resin composition of the present invention may contain a reactive diluent.
From the viewpoint of adhesion reliability, the reactive diluent is preferably a reactive diluent having two or more reactive functional groups in one molecule.

The curable resin composition of the present invention may further contain additives such as coupling agents, dispersants, storage stabilizers, anti-bleeding agents, fluxing agents and leveling agents.

Examples of the method for producing the curable resin composition include a method of mixing a curable resin, a curing agent, a curing accelerator and the like using a mixer. Examples of the mixer include a homodisper, a universal mixer, a Banbury mixer, a kneader, and the like.

A film of the curable resin composition of the present invention before curing can be obtained by coating the curable resin composition on a substrate film and drying it.

INDUSTRIAL APPLICABILITY The curable resin composition of the present invention can be used in a wide range of applications, and can be suitably used in electronic material applications that particularly require high reliability. For example, it can be used as a die attach agent for aviation and automotive electric control unit (ECU) applications, and for power device applications using SiC and GaN. Also, for example, adhesives for power overlay packages, sealants, adhesives for flexible printed circuit boards or coverlay films, copper-clad laminates, adhesives for semiconductor bonding, interlayer insulating films, prepregs, sealants for LEDs, structures It can also be used as an adhesive for materials and the like. Especially, it is suitably used for adhesion of a flexible printed circuit board or a coverlay film.

A cured product of the curable resin composition of the present invention is also one aspect of the present invention.
An adhesive using the curable resin composition of the present invention is also one aspect of the present invention. An adhesive film can be obtained by a method such as drying after coating the adhesive of the present invention on a film. An adhesive film using the adhesive of the present invention is also one aspect of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the curable resin composition which can obtain the hardened|cured material which is excellent in reliability can be provided. Moreover, according to the present invention, it is possible to provide a cured product of the curable resin composition, and an adhesive and an adhesive film using the curable resin composition.

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.

(Synthesis Example 1 (preparation of imide oligomer composition A))
4,4′-(4,4′-Isopropylidenediphenoxy)diphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) 83.3 parts by weight of N-methylpyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., “NMP”) It was dissolved in 150 parts by weight. To the obtained solution was added a solution obtained by diluting 7.1 parts by weight of the diamine represented by the above formula (1) (manufactured by Mitsui Chemicals, "Etacure 100 Plus") with 50 parts by weight of N-methylpyrrolidone, and the temperature was maintained at 25°C. was stirred for 2 hours for reaction to obtain an amic acid oligomer solution. After removing N-methylpyrrolidone from the obtained amic acid oligomer solution under reduced pressure, the solution was heated at 300° C. for 2 hours to obtain an imide oligomer composition A (imidization rate: 99.5%).
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer composition A is an imide oligomer having a structure represented by the above formula (5-1) or (5-3) (A is 4 ,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride residue, B is a divalent group represented by the above formula (3)). Also, the number average molecular weight of the imide oligomer composition A was 3,000.

(Synthesis Example 2 (preparation of imide oligomer composition B))
4,4'-(4,4'-Isopropylidenediphenoxy)diphthalic anhydride 83.3 parts by weight was replaced with 37.2 parts by weight of 4,4'-oxydiphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) An imide oligomer composition B (imidization rate: 99.6%) was obtained in the same manner as in Synthesis Example 1 except that it was used.
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer composition B is an imide oligomer having a structure represented by the above formula (5-1) or (5-3) (A is 4 ,4'-oxydiphthalic anhydride residue, B is a divalent group represented by the above formula (3)). In addition, the number average molecular weight of the imide oligomer composition B was 2,800.

(Synthesis Example 3 (preparation of imide oligomer composition C))
Synthesis Example 1 was repeated except that the amount of Etacure 100 Plus added was changed to 3.6 parts by weight, and 11.2 parts by weight of Priamine 1074 (manufactured by Croda), a hydrogenated dimer diamine, was newly added. An imide oligomer composition C (imidization rate 99.6%) was obtained.
By ¹ H-NMR, GPC, and FT-IR analysis, the imide oligomer composition C is an imide oligomer having a structure represented by the above formula (5-1) or (5-3) (A is 4 , 4'-(4,4'-isopropylidenediphenoxy) diphthalic anhydride residue, B is a divalent group represented by the above formula (3) or a hydrogenated dimer diamine residue). confirmed. Also, the number average molecular weight of the imide oligomer composition C was 3,200.

(Synthesis Example 4 (preparation of imide oligomer composition D))
4,4'-(4,4'-Isopropylidenediphenoxy)diphthalic anhydride 83.3 parts by weight was replaced with 37.2 parts by weight of 4,4'-oxydiphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) An imide oligomer composition D (imidation rate 97) was prepared in the same manner as in Synthesis Example 1 except that 22.4 parts by weight of Priamine 1074 (manufactured by Croda), a hydrogenated dimer diamine, was used in place of Ethacure 100 Plus. .5%) was obtained.
¹ H-NMR, GPC, and FT-IR analysis revealed that the portion corresponding to A in the formula (5-1) or (5-3) in the imide oligomer composition D was 4,4'-oxydiphthal It was confirmed that the portion corresponding to B, which is an acid anhydride residue, contains an imide oligomer which is a hydrogenated dimer diamine residue. In addition, the number average molecular weight of the imide oligomer composition D was 4,800.

(Examples 1 to 6, Comparative Examples 1 to 3)
According to the compounding ratio described in Table 1, each material was stirred and mixed to prepare each curable resin composition.
Each curable resin composition obtained was coated on a substrate PET film and dried to form films of the curable resin compositions of Examples 1 to 5 and Comparative Examples 1 and 2 on the substrate PET film. A compound (about 15 μm thick) was prepared. The obtained film material was laminated so as to have a thickness of about 300 μm, cut to a width of 3 mm and a length of 5 cm, and cured by heating at 190° C. for 1 hour to prepare a cured product.

(Storage elastic modulus and glass transition temperature of cured product before temperature cycle test)
For the cured product of each curable resin composition obtained in Examples and Comparative Examples, using a dynamic viscoelasticity measuring device (manufactured by SII, "EXSTAR6000"), deformation mode: tensile, strain amplitude 10 μm, measurement frequency The dynamic viscoelasticity was measured in the range of 25°C to 250°C under the conditions of 10Hz and a heating rate of 10°C/min to obtain the storage elastic modulus at 25°C and 150°C. Also, the temperature of the maximum value of the loss tangent (tan δ) was determined as the glass transition temperature. Table 1 shows the results.

(Storage elastic modulus and glass transition temperature of cured product after temperature cycle test)
The cured product of each curable resin composition obtained in Examples and Comparative Examples was held at −55° C. for 16 minutes, then heated to 150° C. over 15 minutes, and held at 150° C. for 16 minutes. A temperature cycle test was conducted in which 1000 cycles were performed, one cycle being a cycle in which the temperature was lowered to −55° C. over 15 minutes.
For the cured product after the temperature cycle test, using a dynamic viscoelasticity measuring device (manufactured by SII, "EXSTAR6000"), deformation mode: tensile, strain amplitude 10 μm, measurement frequency 10 Hz, heating rate 10 ° C. / min. The dynamic viscoelasticity was measured in the range of 25°C to 250°C at , and the storage elastic modulus at 25°C and 150°C was determined. Also, the temperature of the maximum value of the loss tangent (tan δ) was determined as the glass transition temperature. Table 1 shows the results.

<Evaluation>
Each curable resin composition obtained in Examples and Comparative Examples was evaluated as follows. Table 1 shows the results.

(Reliability of cured product)
Each curable resin composition obtained was applied to a polyimide substrate having a length of 10 mm and a width of 10 mm, and a silicon chip having a length of 50 μm, a width of 3 mm and a thickness of 3 mm was placed thereon. Then, the curable resin composition was cured by heating at 190° C. for 1 hour to obtain a test piece. The obtained test pieces were evaluated for reliability according to the following "(1) temperature cycle test" and "(2) high temperature holding test" below.

(1) Temperature cycle test After the temperature cycle test was performed on the obtained test piece, the adhesion surface between the silicon chip and the adhesive was visually or microscopically observed from the polyimide side to confirm the presence or absence of cracks and peeling.
Cured product with "○" when no cracks or peeling was confirmed, "△" when cracks were not confirmed but some peeling was seen at the end, and "×" when cracks were confirmed We evaluated the reliability of

(2) High temperature retention test After carrying out a high temperature retention test in which the obtained test piece is held at 175°C for 1000 hours, the bonding surface between the silicon chip and the adhesive is visually or microscopically observed from the polyimide side, and cracks and peeling occur. I checked the presence or absence of
Cured product with "○" when no cracks or peeling was confirmed, "△" when cracks were not confirmed but some peeling was seen at the end, and "×" when cracks were confirmed We evaluated the reliability of

Claims

containing a curable resin and a curing agent,
The curing agent has a structure derived from a diamine represented by the following formula (1),
When the cured product is subjected to a temperature cycle test under the conditions of -55 ° C. to 150 ° C. and 1000 cycles, the change rate of the storage elastic modulus of the cured product at 25 ° C. before and after the temperature cycle test is 25% or less, and A curable resin composition, wherein the rate of change in storage elastic modulus at 150° C. of the cured product before and after the temperature cycle test is 250% or less.
2. The cured product before the temperature cycle test has a storage elastic modulus at 25° C. of 2.8 GPa or more, and the cured product before the temperature cycle test has a storage elastic modulus of 1.3 GPa or more at 150° C. A curable resin composition as described.
3. The curable resin composition according to claim 1, wherein the amount of change in the glass transition temperature of the cured product before and after the temperature cycle test is 15[deg.] C. or less.
The curable resin composition according to claim 1, 2 or 3, wherein the curable resin contains an epoxy resin.
5. The curable resin composition according to claim 1, wherein the curing agent contains an imide oligomer having a structure derived from the diamine represented by formula (1).
A cured product of the curable resin composition according to claim 1, 2, 3, 4 or 5.
An adhesive comprising the curable resin composition according to claim 1, 2, 3, 4 or 5.
An adhesive film using the adhesive according to claim 7.