JP2022096061A - Carboxyl group-containing ester imide resin and ester imide resin composition - Google Patents

Abstract

To provide a carboxyl group-containing ester imide resin which is excellent in flexibility, low boiling point solvent solubility, heat resistance and adhesiveness as an adhesive used in an electronic member and a resin composition for surface protective layer.SOLUTION: A carboxyl group-containing ester imide resin includes a structure represented by the following expression (X) and has imide group concentration of 0.5 mmol/g or more. In the formula (X), n is a number of 0-20, R1 represents an organic group obtained by removing an acid anhydride group from a tetracarboxylic dianhydride, R2 represents an organic group obtained by removing an amino group from dimer acid-derived aliphatic diamine, and R3 represents an organic group obtained by removing a hydroxyl group from polyol.SELECTED DRAWING: None

Description

The present invention relates to a carboxy group-containing esterimide resin and an esterimide resin composition.

Adhesives and surface protective layers used for electronic members are appropriately required to have excellent heat resistance, electrical properties, flexibility, and adhesiveness. In recent years, polyimide resin has been used as a resin having excellent heat resistance.

However, while the polyimide resin is excellent in heat resistance, it lacks flexibility due to its rigid resin structure, and has problems such as inferior bending resistance, low warpage, and adhesiveness. Further, it is necessary to use a high boiling point solvent such as N-methylpyrrolidone (NMP) or gamma-butyrolactone (GBL) to dissolve the resin, and there is a problem that a high temperature heating step of 200 ° C. or higher is required for drying or curing. was there.

To solve the above problems, various resin skeletons having excellent flexibility and solubility have been proposed. For example, Patent Document 1 proposes a polyimide resin having a carbonate structure and a thermosetting resin composition containing an epoxy resin. Further, Patent Document 2 proposes a polyimide resin synthesized from an aliphatic diamine derived from dimer acid and an aromatic tetracarboxylic acid dianhydride.

Japanese Patent No. 6098776 Japanese Patent No. 6031563

The polycarbonate polyimide resin listed in Patent Document 1 is excellent in flexibility and non-amide solvent solubility. However, since the acid anhydride group serving as a cross-linking point with the curing agent is located only at the end of the molecule, the cured product cannot obtain a sufficient cross-linking density and there is a concern about heat resistance.

The polyimide resin having a dimer skeleton mentioned in Patent Document 2 is also excellent in flexibility, but curing requires a dehydration condensation reaction between a ketone group in the polyimide resin and an amino compound (dihydrazide, etc.), which is generated by curing. There is a concern that the water may cause a decrease in adhesive strength and the occurrence of floating or peeling during heating. Even if an epoxy resin is used as the curing agent instead of the amino compound, curing does not occur between the ketone group and the epoxy group.
There is also a method of introducing a carboxyl group as a cross-linking point, but for that purpose, it is necessary to use an expensive aromatic diamine, which is not economical. Furthermore, if the acid value is increased in order to improve the physical properties of the cured product, the number of rigid imide groups derived from aromatic diamines increases, and the flexibility is impaired.
Further, both Patent Documents 1 and 2 tend to require a solvent having a high boiling point in order to completely dissolve the polyimide resin, and as a result, a high-temperature heating step of 200 ° C. or higher is often required for drying and curing. There was still room for improvement in solubility in low boiling point solvents.

Therefore, the present invention is a carboxyl group-containing esterimide resin having excellent flexibility, low boiling point solvent solubility, heat resistance, and adhesion, which can be used for adhesives used for electronic members, surface protective layers, insulating protective films, and the like. , And an esterimide resin composition comprising the resin and an epoxy resin having at least two epoxy groups.

（上記式（Ｘ）中、ｎは０～２０の数であり、且つ、Ｒ^１はテトラカルボン酸二無水物から酸無水物基を除いた有機基を表し、Ｒ^２はダイマー酸由来の脂肪族ジアミンからアミノ基を除いた有機基を表し、Ｒ^３はポリオールから水酸基を除いた有機基を表す。）
［２］ 前記ダイマー酸由来の脂肪族ジアミンからアミノ基を除いた有機基が下記（Ａ）及び式（Ｂ）の少なくともいずれかで表される［１］に記載のカルボキシル基含有エステルイミド樹脂。

（上記式（Ａ）及び（Ｂ）中、Ｙ_１～Ｙ_４はそれぞれ独立して炭素数３～２３のアルキレン基若しくは炭素数３～２３のアルケニレン基であり、Ｒｘ及びＲｙはそれぞれ独立して炭素数３～２３のアルキル基若しくは炭素数３～２３のアルケニル基であり、ｓ及びｔはそれぞれ独立して４以下の数であり、Ｒｘが複数ある場合、それぞれのＲｘは同一でも異なっていてもよく、Ｒｙが複数ある場合、それぞれのＲｙは同一でも異なっていてもよい。）
［３］ 酸価が５～１００ｍｇＫＯＨ／ｇである［１］又は［２］に記載のカルボキシル基含有エステルイミド樹脂。
［４］ 重量平均分子量が１０，０００～２００，０００である［１］～［３］のいずれかに記載のカルボキシル基含有エステルイミド樹脂。
［５］ 弾性率が４００Ｎ／ｍｍ^２以下であり且つ１０％分解温度が３４０℃以上である［１］～［４］のいずれかに記載のカルボキシル基含有エステルイミド樹脂。
［６］ 前記テトラカルボン酸二無水物が３，３’，４，４’－ベンゾフェノンテトラカルボン酸二無水物及び／又は４，４’－（４，４’－イソプロピリデンジフェノキシ）ジフタル酸無水物である［１］～［５］のいずれかに記載のカルボキシル基含有エステルイミド樹脂。
［７］ 大気圧下での沸点が１７０℃以下である有機溶剤中に溶解して成る［１］～［６］に記載のいずれかに記載のカルボキシル基含有エステルイミド樹脂。
［８］ 前記有機溶剤が、シクロヘキサノン、トルエン、及びメチルエチルケトンから選ばれる少なくとも１つである［７］に記載のカルボキシル基含有エステルイミド樹脂。
［９］ ［１］～［８］のいずれかに記載のカルボキシル基含有エステルイミド樹脂と、１分子中に少なくとも２つのエポキシ基を有するエポキシ樹脂とを含むエステルイミド樹脂組成物。 The above object is achieved by the following invention. That is, the present invention is as follows.
[1] A carboxyl group-containing esterimide resin having a structure represented by the following formula (X) and having an imide group concentration of 0.5 mmol / g or more.

(In the above formula (X), n is a number of 0 to 20, R ¹ represents an organic group obtained by removing an acid anhydride group from tetracarboxylic acid dianhydride, and R ² is a fat derived from dimer acid. It represents an organic group obtained by removing an amino group from a group diamine, and R ³ represents an organic group obtained by removing a hydroxyl group from a polyol.)
[2] The carboxyl group-containing esterimide resin according to [1], wherein the organic group obtained by removing the amino group from the aliphatic diamine derived from dimer acid is represented by at least one of the following (A) and the formula (B).

(In the above formulas ( _A ) and (B), Y1 to Y4 are independently alkylene groups having ₃ to 23 carbon atoms or alkenylene groups having 3 to 23 carbon atoms, and Rx and Ry are independent of each other. It is an alkyl group having 3 to 23 carbon atoms or an alkenyl group having 3 to 23 carbon atoms, and s and t are independently numbers of 4 or less, and when there are a plurality of Rx, each Rx is the same but different. Also, when there are a plurality of Rys, each Ry may be the same or different.)
[3] The carboxyl group-containing esterimide resin according to [1] or [2], which has an acid value of 5 to 100 mgKOH / g.
[4] The carboxyl group-containing esterimide resin according to any one of [1] to [3], which has a weight average molecular weight of 10,000 to 200,000.
[5] The carboxyl group-containing esterimide resin according to any one of [1] to [4], which has an elastic modulus of 400 N / mm ² or less and a 10% decomposition temperature of 340 ° C. or higher.
[6] The tetracarboxylic acid dianhydride is 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride and / or 4,4'-(4,4'-isopropylidene diphenoxy) diphthalate anhydride. The carboxyl group-containing esterimide resin according to any one of [1] to [5].
[7] The carboxyl group-containing esterimide resin according to any one of [1] to [6], which is dissolved in an organic solvent having a boiling point of 170 ° C. or lower under atmospheric pressure.
[8] The carboxyl group-containing esterimide resin according to [7], wherein the organic solvent is at least one selected from cyclohexanone, toluene, and methyl ethyl ketone.
[9] An esterimide resin composition comprising the carboxyl group-containing esterimide resin according to any one of [1] to [8] and an epoxy resin having at least two epoxy groups in one molecule.

According to the present invention, a carboxyl group-containing esterimide resin having excellent flexibility, low boiling point solvent solubility, heat resistance, and adhesion, which can be used for adhesives used for electronic members, surface protective layers, insulating protective films, etc. , And an esterimide resin composition containing the resin and an epoxy resin having at least two epoxy groups can be provided.

Hereinafter, the carboxyl group-containing esterimide resin and the esterimide resin composition according to one embodiment of the present invention (the present embodiment) will be described in detail.

上記式（Ｘ）中、ｎは０～２０の数（好ましくは、０～１５の数）であり、且つ、Ｒ^１はテトラカルボン酸二無水物から酸無水物基を除いた有機基を表し、Ｒ^２はダイマー酸由来の脂肪族ジアミンからアミノ基を除いた有機基を表し、Ｒ^３はポリオールから水酸基を除いた有機基を表す。 [Carboxyl group-containing esterimide resin]
The carboxyl group-containing esterimide resin according to the present embodiment includes a structure represented by the following formula (X).

In the above formula (X), n is a number of 0 to 20 (preferably a number of 0 to 15), and R ¹ represents an organic group obtained by removing an acid anhydride group from a tetracarboxylic acid dianhydride. , R ² represents an organic group obtained by removing an amino group from an aliphatic diamine derived from dimer acid, and R ³ represents an organic group obtained by removing a hydroxyl group from a polyol.

The carboxyl group-containing esterimide resin of the present embodiment is a polyimide containing a dimer skeleton, which is a reaction product of tetracarboxylic acid dianhydride and an aliphatic diamine derived from dimer acid (hereinafter, may be referred to as “dimer diamine”). Since it contains a resin structure, it exhibits excellent low boiling point solvent solubility and flexibility. In addition, since it contains a dimer skeleton, it is easily dissolved in a low boiling point organic solvent such as cyclohexanone, toluene, and methyl ethyl ketone, which was difficult to use in the prior art. Further, since the concentration of the imide group in the esterimide resin can be arbitrarily adjusted, heat resistance of the same level or higher can be obtained as compared with the prior art.
Further, one of the features of the carboxyl group-containing esterimide resin is that it contains a half-ester skeleton having a carboxyl group, which is a reaction product of a polyol and an acid anhydride group, in the side chain, and the carboxyl group is contained in the side chain. By having it in, the crosslink density of the cured product obtained in combination with the curing agent is improved, and improvement in heat resistance can be expected. Moreover, since the carboxyl group in the esterimide resin is introduced as a half-ester structure, it is easy to obtain a cured product having excellent flexibility as compared with the conventional polyimide resin.
Furthermore, the ester skeleton contributes to the improvement of the flexibility, adhesion and solubility of the resin.

The dimer diamine used in this embodiment is produced via dimer acid. Fatty acid is a dicarboxylic acid obtained by dimerizing unsaturated fatty acids such as oleic acid and linoleic acid.
The diamine obtained by converting the carboxy group of the dimer acid into an amino group is a diamine diamine, but in the present embodiment, the diamine may or may not have an unsaturated bond in the molecule. That is, in the present embodiment, the carboxy group of dimer acid is converted into an amino group and then hydrogenated to eliminate the unsaturated bond.
The number of carbon atoms of the unsaturated fatty acid used is not particularly limited, but the preferred unsaturated fatty acid is oleic acid or linoleic acid having 18 carbon atoms, which can be obtained as plant-derived fatty acids. , More preferable from the viewpoint of global environment protection.

上記式（Ａ）及び（Ｂ）中、Ｙ_１～Ｙ_４はそれぞれ独立して炭素数３～２３（好ましくは、炭素数３～１０）のアルキレン基若しくは炭素数３～２３（好ましくは、炭素数３～１０）のアルケニレン基であり、Ｒｘ及びＲｙはそれぞれ独立して炭素数３～２３（好ましくは、炭素数３～１０）のアルキル基若しくは炭素数３～２３（好ましくは、炭素数３～１０）のアルケニル基であり、ｓ及びｔはそれぞれ独立して４以下の数（好ましくは、１～３）であり、Ｒｘが複数ある場合、それぞれのＲｘは同一でも異なっていてもよく、Ｒｙが複数ある場合、それぞれのＲｙは同一でも異なっていてもよい。 In the formula (X), the organic group obtained by removing the amino group from the aliphatic diamine derived from dimer acid is based on the structure generally expected as a main component when dimer diamine is produced, and is based on the following (A) and formula (B). ) Is preferably represented by at least one of them.

In the above formulas ( _A ) and (B), Y1 to Y4 are independently alkylene groups having ₃ to 23 carbon atoms (preferably 3 to 10 carbon atoms) or 3 to 23 carbon atoms (preferably carbon atoms). It is an alkaneylene group of number 3 to 10), and Rx and Ry are independently alkyl groups having 3 to 23 carbon atoms (preferably 3 to 10 carbon atoms) or 3 to 23 carbon atoms (preferably 3 carbon atoms). It is an alkenyl group of ~ 10), and s and t are independently numbers of 4 or less (preferably 1 to 3), and when there are a plurality of Rx, each Rx may be the same or different. When there are a plurality of Ry, each Ry may be the same or different.

The formula (A) can be expressed by, for example, the following formulas (1) to (8), but is not limited thereto.

In the above formulas (1) to (8), R ₄ to R ₇ are independently alkylene groups having 2 to 20 carbon atoms (preferably 3 to 10 carbon atoms).

The above formula (B) includes, for example, those represented by at least one of the following formulas (9) to (12), but is not limited thereto.

In the above formulas (9) to (12), R ₄ to R ₇ independently represent an alkylene group having 2 to 20 carbon atoms.

The imide group concentration of the carboxyl group-containing esterimide resin according to the present embodiment is 0.5 mmol / g or more, preferably 0.6 to 2.5 mmol / g, and 1.0 to 2.0 mmol / g. Is more preferable. If it is less than 0.5 mmol / g, sufficient heat resistance cannot be obtained. Further, when it is 2.5 mmol / g or less, sufficient flexibility and adhesiveness can be easily obtained, and a desired carboxyl group-containing esterimide resin can be easily synthesized.
In the present invention, the imide group concentration means the number of imide groups (mmol) per 1 g of the carboxyl group-containing ester imide resin. The imide group concentration can be adjusted by the amount of substance of dimer diamine and the amount of solid content charged including tetracarboxylic acid dianhydride and polyol. Here, the theoretical value (preparation ratio) can be calculated by the following formula.
(Amount of substance of diamine diamine [mol]) x 2 x 1000 / ((prepared solid content [g])-(condensed water [g]))

The amount of the carboxyl group in the carboxyl group-containing esterimide resin may be about 5 to 100 mgKOH / g in acid value, and more preferably 8 to 60 mgKOH / g.
When the acid value is 5 mgKOH / g or more, the crosslink density between the carboxyl group-containing esterimide resin and the epoxy resin becomes high, and the heat resistance of the cured product tends to be excellent. On the other hand, when it is 100 mgKOH / g or less, the crosslink density does not become too high, so that the occurrence of strain is suppressed and the flexibility tends to be excellent.

The acid value can be adjusted by the amount of substance of tetracarboxylic acid dianhydride and dimerdiamine, and the amount of solid content charged including polyol. The theoretical value (preparation ratio) can be calculated by the following formula.
((Amount of substance of tetracarboxylic acid dianhydride [mol])-(Amount of substance of dimerdiamine [mol])) × 2 × 56.1 × 1000 / ((Prepared solid content [g])-(Condensed water [ g]))
The acid value (actual measurement value) of the carboxyl group-containing esterimide resin can be measured according to the method of JIS K1557-5: 2007 by solubilizing the carboxyl group-containing esterimide resin with methyl ethyl ketone (MEK) or the like.

The weight average molecular weight of the carboxyl group-containing esterimide resin is preferably 10,000 to 200,000, more preferably 10,000 to 100,000. In the present specification, the weight average molecular weight and the number average molecular weight mean the values measured by gel permeation chromatography (GPC). For example, it can be measured with the following devices and conditions.

(1) Equipment Equipment: Product name "HLC-8020" (manufactured by Tosoh Corporation)
(2) Column: Product names "TSKgel G2000HXL", "G3000HXL", "G4000GXL" (manufactured by Tosoh Corporation)
(3) Solvent: THF
(4) Flow velocity: 1.0 ml / min
(5) Sample concentration: 2 g / L
(6) Injection amount: 100 μL
(7) Temperature: 40 ° C
(8) Detector: Model number "RI-8020" (manufactured by Tosoh Corporation)
(9) Standard substance: TSK standard polystyrene (manufactured by Tosoh Corporation)

The elastic modulus of the carboxyl group-containing esterimide resin is preferably 400 N / mm ² or less, and more preferably 300 N / mm ² or less. When it is 400 N / mm ² or less, sufficient flexibility can be obtained. Therefore, for example, when combined with an epoxy resin described later, a resin composition having excellent low warpage and metal adhesiveness can be obtained. can.
The elastic modulus of the carboxyl group-containing esterimide resin is based on JIS K-7127 using a test piece prepared from a film of the carboxyl group-containing esterimide resin, and an autograph (manufactured by Shimadzu Corporation, AGS-J) is used. It can be used to perform and measure tensile tests at room temperature (25 ° C.).

The 10% decomposition temperature of the carboxyl group-containing esterimide resin is preferably 340 ° C. or higher, and more preferably 360 ° C. or higher. When the temperature is 340 ° C. or higher, a resin composition having excellent solder reflow resistance and long-term heat resistance can be obtained.
The 10% decomposition temperature of the carboxyl group-containing esterimide resin was raised from room temperature to 5 ° C./min in an atmosphere of 100 ml / min of air using TG-DTA (TG8120, manufactured by Rigaku Co., Ltd.). Measure the temperature at which the weight is reduced by 10% by weight.

The structure of R ² in the carboxyl group-containing esterimide resin represented by the formula (X) is derived from dimer diamine.
The diamine diamine refers to a product produced via dimer acid, and can also be used as a mixture of diamine diamines having structures of the formulas (A) and (B) and the like.

In a general diamine diamine production process, trimeric acid, which is a tricarboxylic acid obtained by trimerizing unsaturated fatty acids, may be produced as a by-product, and trimertriamine converted into an amino group may be present as a by-product. For this reason, commercially available dimer diamines are usually mixtures containing diamine diamines and trimer triamines, and such mixtures can also be used in the present invention.

The number average molecular weight of the diamine diamine may be about 400 to 600, preferably 500 to 580.

In the present invention, a diamine other than diamine diamine (that is, a diamine having no dimer skeleton) is added within a range that does not impair the effects of the present invention (solubility in a low boiling solvent, flexibility, etc.). May be good.

The structure of ^R1 in the carboxyl group-containing esterimide resin represented by the formula (X), which is an essential component of the present invention, is a structure derived from tetracarboxylic acid dianhydride.
Examples of the tetracarboxylic acid dianhydride include 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride (BPDA), pyromellitic acid dianhydride (PMDA), 3,3', 4,4'-. Benzophenone tetracarboxylic acid dianhydride (BTDA), 4,4'-(4,4'-isopropyridene diphenoxy) Diphthalic acid anhydride (BPADA), 3,3', 4,4'-diphenylsulfone tetracarboxylic acid Dianoxide (DSDA), 3,4'-oxydiphthalic acid anhydride (a-ODPA), 4,4'-oxydiphthalic acid anhydride (s-ODPA), 4,4'-(hexafluoroisopropyridene) diphthalic acid Anhydrous (HFDA), Ethylene Glycolbis (Anhydrotrimericate) (TMEG) p-Phenylenebis (Trimeritate Anhydrous) (TAHQ), Cyclobutanetetracarboxylic Acid Dianide, Methylcyclobutanetetracarboxylic Acid Dianide, Cyclo Pentantetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, ethanetetracarboxylic acid dianhydride, 3,3', 4,4'-bicyclohexyltetracarboxylic acid dianhydride Things can be mentioned.
Among them, aromatic tetracarboxylic acid dianhydride is preferable from the viewpoint of heat resistance, and 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride (BPDA), 3,3', 4,4'. -Benzophenone tetracarboxylic acid dianhydride (BTDA), 4,4'-(4,4'-isopropyridene diphenoxy) diphthalic acid anhydride (BPADA), 3,3', 4,4'-diphenylsulfone tetracarboxylic It is preferably at least one selected from the group consisting of acid dianhydride (DSDA), 4,4'-oxydiphthalic acid anhydride (s-ODPA), and tetracarboxylic acid dianhydride is 3,3', 4 , 4'-Benzophenone tetracarboxylic acid dianhydride (BTDA) and / or 4,4'-(4,4'-isopropyridendiphenoxy) diphthalic acid anhydride (BPADA) are more preferred.
A plurality of these tetracarboxylic acid dianhydrides can be combined.

The R3 structure in the carboxyl group-containing ^esterimide resin represented by the formula (X) is a structure derived from a polyol.
The polyol is preferably a bifunctional diol. The polyol may be a short chain diol or a polymer diol.

(1) Short-chain diol The short-chain diol is a compound having a number average molecular weight of less than 500, and is ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4. -Alipid glycols such as butylene glycol, 1,6-hexamethylene glycol and neopentyl glycol, 3-methylpentanediol, 3-methylpropanediol and their alkylene oxide low molar adducts (number average molecular weight less than 500), 1 , 4-Bishydroxymethylcyclohexane and 2-methyl-1,1-cyclohexanedimethanol and other alicyclic glycols and their alkylene oxide low molar adducts (number average molecular weight less than 500), aromatics such as xylylene glycol Glycols and alkylene oxide low molar adducts thereof (number average molecular weight less than 500), bisphenols such as bisphenol A, thiobisphenol and sulfone bisphenol and compounds such as alkylene oxide low molar adducts thereof (number average molecular weight less than 500) can be mentioned. Be done.
Above all, from the viewpoint of reactivity with an acid anhydride group, the hydroxyl group is preferably primary, specifically 1,4-butylene glycol, 3-methylpentanediol, 1,6-hexamethylene glycol, neo. Pentyl glycol, 3-methylpropanediol, 1,4-bishydroxymethylcyclohexane and bisphenol A are preferred.

(2) Polymer diol The polymer diol is a compound having a number average molecular weight of 500 to 4000, and is preferably 500 to 2000. Further, specifically, it is preferably at least one selected from the group consisting of polycarbonate diol, polyester diol, dimer diol, and polybutadiene diol. Examples of the above-mentioned polymer diol include the following.

(Polycarbonate diol)
Polycarbonate diols include polytetramethylene carbonate diols, polypentamethylene carbonate diols, polyneopentyl carbonate diols, polyhexamethylene carbonate diols, poly (1,4-cyclohexanedimethylene carbonate) diols, and their random / block copolymer weights. Examples include coalescence.
Among them, those containing a hexamethylene skeleton are preferable from the viewpoint of improving flexibility and adhesiveness (adhesion).

(Polyester diol)
The polyesterdiol may be at least one of an aliphatic dicarboxylic acid (eg, succinic acid, adipic acid, sebacic acid, glutaric acid and azelaic acid), and an aromatic dicarboxylic acid (eg, isophthalic acid and terephthalic acid). , Low molecular weight glycols (eg, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 3-methylpentanediol, 1,6-hexa) Methylene glycol, neopentyl glycol, 1,4-bishydroxymethylcyclohexane, etc.) and decondensate thereof can be mentioned.

Specifically, polyethylene adipatediol, polybutylene adipatediol, polyhexamethylene adipatediol, polyneopentyl adipatediol, polyethylene / butylene adipatediol, polyneopentyl / hexyl adipatediol, poly-3-methylpentane adipatediol and polybutylene. Examples thereof include isophthalate diol, poly-3-methylpentane terephthalate diol, and poly-3-methylpentane isophthalate diol.

(Dimerdiol)
As the dimer diol, dimer diol, trimer triol or a mixture thereof can be used. The dimer diol is a polyol obtained by reducing the carboxy group of dimer acid to a hydroxyl group, and may or may not have an unsaturated bond in the molecule. Trimmer triol is also a polyol obtained by reducing trimer acid like dimerdiol, and may or may not have an unsaturated bond in its molecule. Commercially available dimer diols are usually mixtures containing dimer diols and trimer triols.
The hydroxyl value of the dimerdiol is preferably 2 mgKOH / g or more, and more preferably 30 mgKOH / g or more.

(Polybutadiene diol)
Examples of the polybutadiene diol include those having a 1,2-vinyl structure, those having a 1,2-vinyl structure and a 1,4-trans structure, and those having a 1,4-trans structure. Further, it may be a hydrogenated polybutadiene polyol, and may be a modified product thereof. The weight average molecular weight of the polybutadiene polyol is preferably 500 to 2000.

These diols ((1) short chain diols, (2) polymer diols) can be used alone or in combination of two or more, but have adhesive (adhesive) properties, durability (heat resistance, water resistance), etc. From the viewpoint of the above, it is more preferable to include a short chain diol, a polycarbonate diol, and a dimer diol.

Next, a method for producing a carboxyl group-containing esterimide resin represented by the general formula (X), which is an essential component of the present invention, will be described. The carboxyl group-containing esterimide resin represented by the formula (X) is obtained by the following manufacturing process.
The above-mentioned dimer diamine, an excess amount of tetracarboxylic acid anhydride and an organic solvent are added, and the mixture is reacted at 100 to 200 ° C. for about 1 to 5 hours with stirring under a nitrogen stream.
Next, add the above-mentioned diol so that the remaining acid anhydride group / hydroxyl group = 1.0, react at 80 to 120 ° C. for about 1 to 5 hours, dilute with an organic solvent, and cool. Obtained at.

Dimer diamine and tetracarboxylic acid anhydride are organic groups obtained by removing an amino group from dimer diamine (aliphatic diamine derived from dimer acid) with respect to organic group ^R1 obtained by removing an acid anhydride group from tetracarboxylic acid anhydride. The molar ratio of R ² (R ¹ / R ² ) may be about 1.04 to 5.00, preferably 1.04 to 2.10.
When the molar ratio (R ¹ / R ² ) is 1.04 or more, the carboxyl group concentration (acid value) does not become too low, and excellent physical properties (heat resistance, etc.) are likely to be developed. When the molar ratio (R ¹ / R ² ) is 5.00 or less, the imide group concentration does not become too low, and good heat resistance can be maintained. More preferably, it is 1.04 to 2.00.

To confirm that the polyamic acid is completely imidized, use a Fourier transform infrared spectrophotometer (FT-IR) to absorb the obtained esterimide resin from the imide group near 1750 cm ^-1 by the ATR method. It can be confirmed by confirmation and measurement of acid value.

The organic solvent used at the time of production is preferably an organic solvent having a boiling point of 170 ° C. or lower, particularly a non-nitrogen solvent. When the boiling point of the solvent is less than 170 ° C., the coating composition using the esterimide resin composition of the present invention can be dried and cured at a low temperature and in a short time. Further, it is preferable not to use a nitrogen-based organic solvent which is highly harmful to the human body.
Therefore, the carboxyl group-containing esterimide resin according to the present embodiment may be in the form of being dissolved in an organic solvent having a boiling point of 170 ° C. or lower under atmospheric pressure (carboxyl group-containing esterimide resin solution). In this case, the solid content concentration is preferably about 30 to 60% by mass. The solid content concentration can be determined by heating a predetermined amount of the resin solution in an oven dryer at 150 ° C. for 2 hours.

Examples of the organic solvent include toluene, cyclohexane, methylcyclohexane, ethylene glycol diethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, ethyl acetate, n-butyl acetate and isoamyl acetate. , Acetone, Methylethylketone, Cyclopentanone, Cyclohexanone, Dimethylcarbonate, tetrahydrofuran, Dioxane, etc. These may be used alone or in combination of two or more.
Of these, toluene, methyl ethyl ketone, cyclopentanone, and cyclohexanone are preferable because of their solubility, and the efficiency of drying the coating composition using the esterimide resin (low temperature, short time), etc., and are particularly selected from cyclohexanone, toluene, and methyl ethyl ketone. At least one is preferable.

The carboxyl group-containing esterimide resin can be produced without using a catalyst, but it can also be produced in the presence of a catalyst as listed below in order to promote the reaction.
For example, basic catalysts such as triethylamine, tributylamine, diazabicycloundecene (DBU), triethylenediamine (DABCO), and pyridine can be used. These preferable amounts are 0.01 to 2 equivalents with respect to the mol number of the polyol compound used.

[Esterimide resin composition]
The esterimide resin composition according to the present embodiment contains the above-mentioned carboxyl group-containing esterimide resin of the present invention and an epoxy resin having at least two epoxy groups in one molecule.

Examples of the epoxy resin include bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated bisphenol A type epoxy resin, phenol novolac type epoxy resin, o-cresol novolac type epoxy resin, and flexibility. Epoxy resin, epoxidized polybutadiene, amine type epoxy resin, heterocycle-containing epoxy resin, alicyclic epoxy resin, bisphenol S type epoxy resin, dicyclopentadiene type epoxy resin, triglycidyl isocyanurate, bixilenol type epoxy resin, glycidyl group Examples thereof include compounds having. These can be used alone or in combination of two or more.

The epoxy equivalent of the epoxy resin is not particularly limited, and is preferably 100 to 10,000 g / eq, more preferably 100 to 400 g / eq, from the viewpoint of mechanical strength and tightness of the cured product.

The weight average molecular weight of the epoxy resin is preferably 100 to 70,000, more preferably 300 to 25,000, from the viewpoint of compatibility with the above-mentioned carboxyl group-containing esterimide resin of the present invention.

Further, by adjusting the ratio of the epoxy group and the carboxyl group involved in thermosetting, the characteristics can be set in a desired range.
Specifically, the ratio of the epoxy group to the carboxyl group is preferably epoxy group / carboxyl group (molar ratio) = 10/1 to 1/1, more preferably 3/1 to 1/1. If it exceeds the above range, the crosslinkability tends to be deteriorated and the heat resistance is lowered.
The content of the epoxy resin is preferably in the range of 2 to 100 parts by mass, more preferably in the range of 3 to 60 parts by mass, with respect to 100 parts by mass of the carboxyl group-containing esterimide resin (solid content) of the present invention. When the content of the epoxy resin is 2 parts by mass or more, the crosslinkability is good, and when it is 100 parts by mass or less, the crosslinkability is less likely to decrease, so that heat resistance, adhesiveness and the like can be improved. can.

The esterimide resin composition according to the present embodiment can be prepared by mixing the above-mentioned carboxyl group-containing esterimide resin of the present invention and the above-mentioned epoxy resin in a predetermined ratio. At the time of preparation, the epoxy resin may be mixed in the presence of the above-mentioned organic solvent, or may be prepared by mixing an epoxy resin with a carboxyl group-containing esterimide resin dissolved in the organic solvent. Further, a known additive may be mixed as appropriate.

The esterimide resin composition according to the present embodiment can be used as, for example, a coating composition by using a low boiling point solvent. When used as a paint composition, it is provided as an adhesive for electronic members that can be dried and cured at low temperatures and has excellent heat resistance, flexibility, and adhesiveness, or as a paint resin composition that can be used as an insulating protective film or the like. be able to.

The above-mentioned coating composition contains the above-mentioned carboxyl group-containing esterimide resin and epoxy resin as essential components, which are dissolved in an organic solvent. The coating composition can be used for applications such as solder resists, electromagnetic wave shielding films, and paints, and as adhesives for flexible printed substrate adhesives, conductive adhesives, structural material adhesives, and the like.

As the organic solvent used in the coating composition, any organic solvent in which the above essential components are dissolved can be used, but considering the processing conditions used as the coating material, the boiling point is the organic solvent. It is preferable that the solvent is a non-nitrogen solvent having a temperature of 170 ° C. or lower. When the boiling point of the solvent is 170 ° C. or lower, the coating composition can be dried and cured at a low temperature. Further, it is preferable not to use a nitrogen-based organic solvent which is highly harmful to the human body.

Examples of the organic solvent include toluene, cyclohexane, methylcyclohexane, ethylene glycol diethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, ethyl acetate, n-butyl acetate and isoamyl acetate. , Acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, dimethyl carbonate and the like. These may be used alone or in combination of two or more.
In particular, toluene, methyl ethyl ketone, cyclopentanone, and cyclohexanone are preferable because of their solubility and the efficiency of drying the coating composition using the esterimide resin (low temperature, short time).

The coating composition of the present invention contains an appropriate amount of a curing accelerator, an isocyanate-based cross-linking agent, a thermoplastic polymer, a tackifier resin, a pigment, an antioxidant, an ultraviolet absorber, a surfactant, a filler and the like, if necessary. May be.

After coating, the coating composition of the present invention is preferably cured at 60 to 170 ° C., more preferably 120 to 150 ° C. before use.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Further, "part" in the following indicates a mass part, and "%" indicates a mass%.

The materials used are as follows.
(1) Diamine / dimer diamine (number average molecular weight 561, manufactured by CRODA, trade name: preamine 1074 (P1074))
・ Isophorone diamine (IPDA)
・ 3,5-Diaminobenzoic acid (3,5-DABA)

(2) Tetracarboxylic acid dianhydride ・ 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride (BTDA)
4,4'-(4,4'-isopropylidene diphenoxy) diphthalic acid anhydride (BPADA)

(3) Polyol Polycarbonate Diol A: Polyhexamethylene carbonate diol (number average molecular weight 2010, manufactured by Ube Kosan Co., Ltd., trade name: Ethanacole UH200)
Polycarbonate diol B: polyhexamethylene carbonate diol (number average molecular weight 983, manufactured by Ube Kosan Co., Ltd., trade name: Ethanacole UH100)
Polycarbonate diol C: polyhexamethylene carbonate diol (number average molecular weight 511, manufactured by Ube Kosan Co., Ltd., trade name: Ethanacole UH50)
-Polyester polyol: poly-3-methylpentane isophthalatediol (number average molecular weight 994, manufactured by Kuraray Co., Ltd., trade name: Kuraray polyol P-1030)
Dimerdiol: (number average molecular weight 511, manufactured by CRODA, trade name: prepole 2033)
-1,4butanediol (1,4BD)

(4) Epoxy resin / Epoxy resin A: Bisphenol A type epoxy resin (epoxy equivalent 184 to 194 g / eq, weight average molecular weight 370, manufactured by Mitsubishi Chemical Corporation, trade name: jER828)

[Manufacturing Example 1]
<Carboxyl group-containing esterimide resin A>
A separable flask equipped with a stirrer is charged with 50.0 parts by mass of preamine 1074 and 131.4 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 81.1 parts by mass of BPADA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 134.9 parts by mass of Ethanacole UH200 was added, and after stirring at 100 to 120 ° C. for 5 hours, 131.4 parts by mass of toluene and 131.4 parts by mass of methyl ethyl ketone were added to dilute the mixture. By cooling to room temperature, a carboxyl group-containing esterimide resin solution A designed to have a solid content concentration of 40% and an acid value of 30 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 30 mgKOH / g, which was the same as the design value (theoretical value), it was confirmed that the acid value was completely imidized. The weight average molecular weight was 40,000, and the imide group concentration calculated from the charging ratio was 0.7 mmol / g.

[Manufacturing Example 2]
<Carboxyl group-containing esterimide resin B>
A separable flask equipped with a stirrer is charged with 100.0 parts by mass of preamine 1074 and 179.4 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 86.2 parts by mass of BTDA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 179.2 parts by mass of Ethanacole UH200 was added, and after stirring at 100 to 120 ° C. for 5 hours, 179.4 parts by mass of toluene was added and 179.4 parts by mass of methyl ethyl ketone was added to dilute the mixture. By cooling to room temperature, a carboxyl group-containing esterimide resin solution B designed to have a solid content concentration of 40% and an acid value of 30 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 30 mgKOH / g, which was the same as the design value (theoretical value), it was confirmed that the acid value was completely imidized. The weight average molecular weight was 40,000, and the imide group concentration calculated from the charging ratio was 1.0 mmol / g.

[Manufacturing Example 3]
<Carboxyl group-containing esterimide resin C>
A separable flask equipped with a stirrer is charged with 100.0 parts by mass of preamine 1074 and 116.0 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 77.5 parts by mass of BTDA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 61.4 parts by mass of Ethanacole UH100 was added, and after stirring at 100 to 120 ° C. for 5 hours, 116.0 parts by mass of toluene and 116.0 parts by mass of methyl ethyl ketone were added to dilute the mixture. By cooling to room temperature, a carboxyl group-containing esterimide resin solution C designed to have a solid content concentration of 40% and an acid value of 30 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 30 mgKOH / g, which was the same as the design value (theoretical value), it was confirmed that the acid value was completely imidized. The weight average molecular weight was 40,000, and the imide group concentration calculated from the charging ratio was 1.5 mmol / g.

[Manufacturing Example 4]
<Carboxyl group-containing esterimide resin D>
A separable flask equipped with a stirrer is charged with 100.0 parts by mass of preamine 1074 and 124.4 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 124.2 parts by mass of BPADA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 30.9 parts by mass of Ethanacole UH50 was added, and after stirring at 100 to 120 ° C. for 5 hours, 124.4 parts by mass of toluene and 124.4 parts by mass of methyl ethyl ketone were added to dilute the mixture. By cooling to room temperature, a carboxyl group-containing esterimide resin solution D designed to have a solid content concentration of 40% and an acid value of 30 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 30 mgKOH / g, which was the same as the design value (theoretical value), it was confirmed that the acid value was completely imidized. The weight average molecular weight was 40,000, and the imide group concentration calculated from the charging ratio was 1.4 mmol / g.

[Manufacturing Example 5]
<Carboxyl group-containing esterimide resin E>
A separable flask equipped with a stirrer is charged with 100.0 parts by mass of preamine 1074 and 98.5 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 74.7 parts by mass of BTDA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 26.5 parts by mass of Ethanacole UH100, 2.4 parts by mass of 1,4 butanediol are added, and after stirring at 100 to 120 ° C. for 5 hours, 98.5 parts by mass of toluene, 98. By adding 5.5 parts by mass of methyl ethyl ketone to dilute and cooling to room temperature, a carboxyl group-containing esterimide resin solution E designed to have a solid content concentration of 40% and an acid value of 30 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 30 mgKOH / g, which was the same as the design value (theoretical value), it was confirmed that the acid value was completely imidized. The weight average molecular weight was 40,000, and the imide group concentration calculated from the charging ratio was 1.8 mmol / g.

[Manufacturing Example 6]
<Carboxyl group-containing esterimide resin F>
A separable flask equipped with a stirrer is charged with 100.0 parts by mass of preamine 1074 and 84.7 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 71.8 parts by mass of BTDA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 4.0 parts by mass of 1,4 butanediol is added, and after stirring at 100 to 120 ° C. for 5 hours, 84.7 parts by mass of toluene and 84.7 parts by mass of methyl ethyl ketone are added. By diluting and cooling to room temperature, a carboxyl group-containing esterimide resin solution F designed to have a solid content concentration of 40% and an acid value of 30 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 30 mgKOH / g, which was the same as the design value (theoretical value), it was confirmed that the acid value was completely imidized. The weight average molecular weight was 40,000, and the imide group concentration calculated from the charging ratio was 2.1 mmol / g.

[Manufacturing Example 7]
<Carboxyl group-containing esterimide resin G>
A separable flask equipped with a stirrer is charged with 100.0 parts by mass of preamine 1074 and 109.0 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 99.2 parts by mass of BPADA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 25.2 parts by mass of Ethanacole UH200 is added, and after stirring at 100 to 120 ° C. for 5 hours, 109.0 parts by mass of toluene and 109.0 parts by mass of methyl ethyl ketone are added to dilute the mixture. By cooling to room temperature, a carboxyl group-containing esterimide resin solution G designed to have a solid content concentration of 40% and an acid value of 6 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 6 mgKOH / g, which was the same as the design value (theoretical value), it was confirmed that the acid value was completely imidized. The weight average molecular weight was 30,000, and the imide group concentration calculated from the charging ratio was 1.6 mmol / g.

[Manufacturing Example 8]
<Carboxyl group-containing esterimide resin H>
A separable flask equipped with a stirrer is charged with 100.0 parts by mass of preamine 1074 and 157.2 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 120.6 parts by mass of BTDA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 100.2 parts by mass of Ethanacole UH50 was added, and after stirring at 100 to 120 ° C. for 5 hours, 157.2 parts by mass of toluene and 157.2 parts by mass of methyl ethyl ketone were added to dilute the mixture. By cooling to room temperature, a carboxyl group-containing esterimide resin solution H designed to have a solid content concentration of 40% and an acid value of 70 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 70 mgKOH / g, which was the same as the design value (theoretical value), it was confirmed that the acid value was completely imidized. The weight average molecular weight was 40,000, and the imide group concentration calculated from the charging ratio was 1.1 mmol / g.

[Manufacturing Example 9]
<Carboxyl group-containing esterimide resin I>
A separable flask equipped with a stirrer is charged with 50.0 parts by mass of preamine 1074 and 176.2 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 99.6 parts by mass of BPADA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 206.1 parts by mass of Ethanacole UH200 was added, and after stirring at 100 to 120 ° C. for 5 hours, 176.2 parts by mass of toluene was added and 176.2 parts by mass of methyl ethyl ketone was added to dilute the mixture. By cooling to room temperature, a carboxyl group-containing esterimide resin solution I designed to have a solid content concentration of 40% and an acid value of 30 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 30 mgKOH / g, which was the same as the design value, it was confirmed that the acid value was completely imidized. The weight average molecular weight was 40,000, and the imide group concentration calculated from the charging ratio was 0.5 mmol / g.

[Manufacturing Example 10]
<Carboxyl group-containing esterimide resin J>
A separable flask equipped with a stirrer is charged with 100.0 parts by mass of preamine 1074 and 116.6 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 77.5 parts by mass of BTDA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 62.0 parts by mass of Clare polyol P-1030 is added, and after stirring at 100 to 120 ° C. for 5 hours, 116.6 parts by mass of toluene and 116.6 parts by mass of methyl ethyl ketone are added. By diluting and cooling to room temperature, a carboxyl group-containing esterimide resin solution J designed to have a solid content concentration of 40% and an acid value of 30 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 30 mgKOH / g, which was the same as the design value (theoretical value), it was confirmed that the acid value was completely imidized. The weight average molecular weight was 30,000, and the imide group concentration calculated from the charging ratio was 1.5 mmol / g.

[Manufacturing Example 11]
<Carboxyl group-containing esterimide resin K>
A separable flask equipped with a stirrer is charged with 100.0 parts by mass of preamine 1074 and 124.4 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 124.2 parts by mass of BPADA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 31.0 parts by mass of Prepole 2033 was added, and after stirring at 100 to 120 ° C. for 5 hours, 124.4 parts by mass of toluene and 124.4 parts by mass of methyl ethyl ketone were added to dilute the mixture. By cooling to room temperature, a carboxyl group-containing esterimide resin solution K designed to have a solid content concentration of 40% and an acid value of 30 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 30 mgKOH / g, which was the same as the design value (theoretical value), it was confirmed that the acid value was completely imidized. The weight average molecular weight was 30,000, and the imide group concentration calculated from the charging ratio was 1.4 mmol / g.

[Manufacturing Comparative Example 1]
<Carboxyl group-containing esterimide resin L>
A separable flask equipped with a stirrer is charged with 30.0 parts by mass of isophoronediamine and 122.6 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 79.6 parts by mass of BTDA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 142.5 parts by mass of Ethanacole UH200 was added, and the mixture was stirred at 100 to 120 ° C., but was insolubilized during the reaction.

[Manufacturing Comparative Example 2]
<Carboxyl group-containing esterimide resin M>
A separable flask equipped with a stirrer is charged with 30.0 parts by mass of isophorone diamine and 169.3 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 137.7 parts by mass of BPADA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 178.1 parts by mass of Ethanacole UH200 was added, and the mixture was stirred at 100 to 120 ° C., but was insolubilized during the reaction.

[Manufacturing Comparative Example 3]
<Carboxyl group-containing esterimide resin N>
A separable flask equipped with a stirrer is charged with 30.0 parts by mass of preamine 1074 and 176.8 parts by mass of cyclohexanone, heated and stirred at 100 ° C., and then 89.0 parts by mass of BPADA is added to form a nitrogen stream. , 160 ° C. for 4 hours to obtain a polyimide solution having an acid anhydride group at the terminal. After cooling to 60 ° C. or lower, 236.6 parts by mass of Ethanacole UH200 was added, and after stirring at 100 to 120 ° C. for 5 hours, 176.8 parts by mass of toluene and 176.8 parts by mass of methyl ethyl ketone were added to dilute the mixture. By cooling to room temperature, a carboxyl group-containing esterimide resin solution N designed to have a solid content concentration of 40% and an acid value of 40 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 40 mgKOH / g, which was the same as the design value, it was confirmed that the acid value was completely imidized. The weight average molecular weight was 30,000, and the imide group concentration calculated from the charging ratio was 0.3 mmol / g.

[Manufacturing Comparative Example 4]
<Carboxyl group-containing imide resin O>
A separable flask equipped with a stirrer was charged with 100.0 parts by mass of preamine 1074, 24.0 parts by mass of 3,5-diaminobenzoic acid, and 292.0 parts by mass of cyclohexanone, and then heated and stirred at 100 ° C. , 180.1 parts by mass of BPADA, nitrogen stream, and reaction at 160 ° C. for 7 hours, then add 140.6 parts by mass of methyl ethyl ketone to dilute and cool to room temperature to have a solid content concentration of 40%. , A carboxyl group-containing imide resin solution O designed to have an acid value of 30 mgKOH / g was obtained.
Absorption derived from the imide group was confirmed using FT-IR, and since the acid value of the measured solid content was 30 mgKOH / g, which was the same as the design value, it was confirmed that the acid value was completely imidized. The weight average molecular weight was 40,000, and the imide group concentration calculated from the charging ratio was 2.4 mmol / g.

The following solubility tests were performed on the carboxyl group-containing ester imide resin resin solutions obtained in Production Examples 1 to 11 and Production Comparative Examples 1 to 3 and the carboxyl group-containing imide resin resin solutions obtained in Production Comparative Example 4. Solution stability test), tensile test, heat resistance test and adhesion test were performed. The results are shown in Table 1 below.

(Solubility test)
The solubility of the resin solutions of the resins A to O during and after the synthesis was evaluated.
〇: No turbidity or precipitates after 1 month after storage at 5 ° C Δ: Turbidity or precipitation within 1 month after storage at 5 ° C ×: Insolubilization during synthesis

(Tensile test)
A resin solution of resins A to K, N, and O was applied on the entire surface of the release paper, and then dried at 120 ° C. for 10 minutes. The coating was performed so that the thickness of the carboxyl group-containing esterimide resin after drying was 30 μm. Then, the coating film was cut into a length of 60 mm and a width of 15 mm to prepare a test piece. Using the obtained test piece, a tensile test was carried out at room temperature (25 ° C.) using an autograph (manufactured by Shimadzu Corporation, AGS-J) in accordance with JIS K-7127, and the elastic modulus was measured.
〇: Elastic modulus of 400 N / mm ² or less Δ: Elastic modulus of more than 400 N / mm ² and 800 N / mm ² or less ×: Elastic modulus of 800 N / mm ² or less

(Heat resistance test)
A resin solution of resins A to K, N, and O was applied on the entire surface of the release paper, and then dried at 120 ° C. for 10 minutes. The coating was performed so that the thickness of the carboxyl group-containing esterimide resin after drying was 30 μm. Then, the release paper was peeled off to obtain a test piece made of a film of a carboxyl group-containing esterimide resin.

Next, using TG-DTA (TG8120, manufactured by Rigaku Co., Ltd.), the temperature was raised from room temperature to 5 ° C./min under an atmosphere of 100 ml / min of air to obtain a TG-DTA curve. Then, attention was paid to the temperature at which the weight was reduced by 10% by mass (10% decomposition temperature), and the heat resistance was determined.
〇: The 10% decomposition temperature is 360 ° C. or higher.
Δ: The 10% decomposition temperature is 340 ° C. or higher and lower than 360 ° C.
X: The 10% decomposition temperature is less than 340 ° C.

(Adhesion test)
A test piece was prepared by applying a resin solution of resins A to K, N, and O to the copper surface side of the copper-clad laminate and then drying at 120 ° C. for 10 minutes. The coating was performed so that the thickness of the carboxyl group-containing esterimide resin after drying was 20 μm. The adhesion test was evaluated in accordance with JIS K 5600-5-6 by forming a cross cut of 100 squares with a cut interval of 1 mm and observing the appearance after peeling the cellophane tape.
〇: No peeling Δ: The peeled square is 50 squares or more and less than 100 squares ×: The peeled square is less than 50 squares

[Resin composition]
With respect to the resin solutions of the resins A to K, N, and O, the epoxy resin A was blended with the formulations shown in Table 2 below to prepare the resin compositions of Examples 1 to 11 and Comparative Examples 3 and 4.
The obtained resin composition was subjected to the following warp resistance test, solder reflow resistance test, 200 ° C. long-term heat resistance test, and metal adhesiveness test. The results are shown in Table 2 below.

(Warpability test)
The obtained resin composition was applied to a 50 μm-thick polyimide film to a thickness of 20 μm (dry thickness), heated at 120 ° C. for 10 minutes to dry, and then heated at 150 ° C. for 3 hours to cure. .. The obtained coating film was cut into 5 cm × 5 cm, and after adjusting the temperature to 25 ° C., it was placed on a horizontal glass plate and the average value of the warp heights at the four corners was measured.
〇: Height less than 5 mm Δ: Height 5 mm or more and less than 15 mm ×: Height 15 mm or more

(Solder reflow resistance test)
The obtained resin composition was applied onto the entire surface of the release paper on one side, heated at 120 ° C. for 10 minutes to dry, and then the release paper was peeled off to prepare a film having a thickness of 20 μm.
The film was attached to the copper surface (dimensions 5 cm × 7 cm) of the copper-clad laminate, and the copper surface of another copper-clad laminate was further laminated on the film, and heat-pressed at 150 ° C. for 1 minute at 1 MPa pressure. Then, it was cut into a size of 3 cm × 3 cm and cured by heating at 150 ° C. for 3 hours to prepare a test piece. After floating this test piece in a solder bath at 288 ° C. for 30 seconds, abnormal appearance (floating, peeling) was confirmed.
〇: No abnormality after 30 seconds Δ: No abnormality after 20 seconds, but abnormal occurrence after 30 seconds ×: Abnormality occurred before 20 seconds

(Long-term heat resistance test)
Each of the test pieces prepared in the same manner as in the solder reflow resistance test was confirmed to have abnormal appearance (floating, peeling) after being placed in an oven at 200 ° C. for 24 hours.
〇: No abnormality at the lapse of 24 hours Δ: No abnormality at the lapse of 10 hours, but an abnormality occurred at the lapse of 24 hours ×: Abnormality occurred before the lapse of 10 hours

(Metal adhesion test)
The prepared resin composition was applied onto the entire surface of the release paper on one side, heated at 120 ° C. for 10 minutes to dry, and then the release paper was peeled off to prepare a film having a thickness of 20 μm.
The film was attached to the copper surface (dimensions 5 cm × 7 cm) of the copper-clad laminate, and the copper surface of another copper-clad laminate was further laminated on the film, and heat-pressed at 150 ° C. for 1 minute at 1 MPa pressure. Then, it was cured by heating at 150 ° C. for 3 hours, and then cut into a size of 10 mm in width and 70 mm in length to prepare a test piece.
In the metal adhesion test, the adhesive strength was evaluated by peeling at a tensile speed of 100 mm / min and 180 degrees using an autograph (manufactured by Shimadzu Corporation, AGS-J).
〇: Adhesive strength is 7 N / cm or more Δ: Adhesive strength is 3 N / cm or more, less than 7 N / cm ×: Adhesive strength is less than 3 N / cm

なお、表１中のＲ^１／Ｒ^２は、テトラカルボン酸無水物から酸無水物基を除いた有機基Ｒ^１に対し、ダイマージアミンからアミノ基を除いた有機基Ｒ^２のモル比である。

In addition, R ¹ / R ² in Table 1 is the molar ratio of the organic group ^R2 which removed the amino group from the dimerdiamine to the organic group ^R1 which removed the acid anhydride group from the tetracarboxylic acid anhydride. ..

As shown in Table 1, the carboxyl group-containing esterimide resin of the present invention was excellent in solubility in a low boiling point solvent, flexibility, heat resistance, and adhesion.
On the other hand, the esterimide resin containing no dimer skeleton shown in Comparative Examples 1 and 2 was insolubilized during the reaction as the molecular weight increased. It is considered that this is because the bulkiness of the dimer skeleton was lost, and the inherent rigid and easily aggregated property of the imide group was exhibited. In particular, it is presumed that the solubility of non-dimer-based imide resins in low boiling point solvents such as toluene and methyl ethyl ketone is very low.
Further, the esterimide resin of Production Comparative Example 3 was inferior in heat resistance. This is considered to be due to the low concentration of imide groups.
The carboxyl group-containing imide resin of Production Comparative Example 4 was excellent in heat resistance and solubility, but lacked flexibility. This is due to the rigid imide group derived from the aromatic diamine used to impart the carboxyl group. In this example, a half-ester structure generated from the reaction between an acid anhydride and a hydroxyl group is used to impart a carboxyl group to the esterimide resin, and it is considered that this greatly contributes to the improvement of flexibility.

Further, as shown in Table 2, the composition of the esterimide resin and the epoxy resin of the present invention was excellent in flexibility, heat resistance, and metal adhesion, but the esterimide having a low imide group concentration in Comparative Example 3 The resin composition was inferior in long-term heat resistance, and the imide resin composition of Comparative Example 4 was inferior in flexibility and adhesiveness.
As described above, it can be said that the resin composition of the present invention has flexibility, heat resistance, and adhesiveness.

According to the carboxyl group-containing esterimide resin of the present invention, it is possible to provide a resin composition having excellent low boiling point solvent solubility, heat resistance, flexibility, and adhesion to a metal. Therefore, as a heat-resistant paint that can be dried or cured at a low temperature, it is useful as an adhesive for flexible printed substrates, an insulating protective film, or the like.

Claims (9)

A carboxyl group-containing esterimide resin having a structure represented by the following formula (X) and having an imide group concentration of 0.5 mmol / g or more.

(In the above formula (X), n is a number of 0 to 20, R ¹ represents an organic group obtained by removing an acid anhydride group from tetracarboxylic acid dianhydride, and R ² is a fat derived from dimer acid. It represents an organic group obtained by removing an amino group from a group diamine, and R ³ represents an organic group obtained by removing a hydroxyl group from a polyol.) The carboxyl group-containing esterimide resin according to claim 1, wherein the organic group obtained by removing the amino group from the aliphatic diamine derived from dimer acid is represented by at least one of the following (A) and the formula (B).

(In the above formulas ( _A ) and (B), Y1 to Y4 are independently alkylene groups having ₃ to 23 carbon atoms or alkenylene groups having 3 to 23 carbon atoms, and Rx and Ry are independent of each other. It is an alkyl group having 3 to 23 carbon atoms or an alkenyl group having 3 to 23 carbon atoms, and s and t are independently numbers of 4 or less, and when there are a plurality of Rx, each Rx is the same but different. Also, when there are a plurality of Rys, each Ry may be the same or different.) The carboxyl group-containing esterimide resin according to claim 1 or 2, wherein the acid value is 5 to 100 mgKOH / g. The carboxyl group-containing esterimide resin according to any one of claims 1 to 3, wherein the weight average molecular weight is 10,000 to 200,000. The carboxyl group-containing esterimide resin according to any one of claims 1 to 4, wherein the elastic modulus is 400 N / mm ² or less and the 10% decomposition temperature is 340 ° C. or higher. The tetracarboxylic acid dianhydride is 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride and / or 4,4'-(4,4'-isopropylidene diphenoxy) diphthalic acid anhydride. The carboxyl group-containing esterimide resin according to any one of claims 1 to 5. The carboxyl group-containing esterimide resin according to any one of claims 1 to 6, which is dissolved in an organic solvent having a boiling point of 170 ° C. or lower under atmospheric pressure. The carboxyl group-containing esterimide resin according to claim 7, wherein the organic solvent is at least one selected from cyclohexanone, toluene, and methyl ethyl ketone. An esterimide resin composition comprising the carboxyl group-containing esterimide resin according to any one of claims 1 to 8 and an epoxy resin having at least two epoxy groups in one molecule.