TWI844625B - Hardening resin composition - Google Patents

Abstract

[Topic] To provide a curable resin composition whose cured product has both excellent heat resistance and dielectric properties, and the cured product thereof, a prepreg having these properties, a circuit board, a build-up film, a semiconductor packaging material, and a semiconductor device. [Solution] The curable resin composition of the present invention is characterized by containing a maleimide (A) having a dihydroindene skeleton and a cyanate compound (B).

Description

Hardening resin composition

The present invention relates to a curable resin composition, a cured product obtained from the curable resin composition, a prepreg, a circuit board, a build-up film, a semiconductor packaging material, and a semiconductor device.

As materials for circuit boards for electronic devices, the following are widely used: prepregs obtained by impregnating glass fiber cloth with thermosetting resins such as epoxy resins and BT (bismaleimide-tris) resins and then heating and drying; laminates obtained by heating and curing the prepreg; and multi-layer boards obtained by combining the laminate and the prepreg and then heating and curing. As semiconductor package substrates become thinner, the warping of the package substrate during installation has become a problem, so in order to suppress this, materials with high heat resistance are sought.

In recent years, as signals have been increasing in speed and frequency, it is desired to provide a thermosetting resin composition that can provide a cured product that maintains a sufficiently low dielectric constant and exhibits a sufficiently low dielectric loss tangent under such an environment.

In particular, recently, in various electrical material applications, especially in advanced material applications, further improvement of performance represented by heat resistance and dielectric properties, as well as materials and compositions having these properties are sought.

In response to these demands, maleimide resins have attracted attention as materials that have both heat resistance and low dielectric constant and dielectric loss tangent. However, although conventional maleimide resins have high heat resistance, their dielectric constant and dielectric loss tangent values have not reached the level required for advanced material applications. In addition, they are difficult to dissolve in solvents and have poor workability. Therefore, there is a strong demand for the development of resins that maintain heat resistance while showing a further low dielectric constant and dielectric loss tangent and excellent solvent solubility.

On the other hand, as a cyanate-based material having both high dielectric properties and heat resistance, a resin composition obtained by blending a phenol novolac-type cyanate resin, a bisphenol A cyanate resin, and a non-halogen epoxy resin is known (see Patent Document 1).

However, although the resin composition described in the aforementioned patent document 1 improves the heat resistance and dielectric properties of the cured product to a certain extent, the heat resistance is still not up to the level required in recent years. [Prior technical document] [Patent document]

[Patent Document 1] Japanese Patent Application Publication No. 2004-182850

[Problems to be solved by the invention]

Therefore, the problem to be solved by the present invention is to provide a curable resin composition whose cured product has both excellent heat resistance and dielectric properties, and its cured product, prepreg, circuit board, build-up film, semiconductor packaging material, and semiconductor device having these properties. [Means for solving the problem]

Therefore, the inventors of the present invention have made intensive researches to solve the above problems, and have found that a curable resin composition containing a maleimide (A) having an indene skeleton and a cyanate compound (B) can make its cured product have a low dielectric constant and a low dielectric loss tangent, and also have excellent heat resistance, thereby completing the present invention.

That is, the present invention relates to a curable resin composition, which is characterized by containing a maleimide (A) having an indene skeleton and a cyanate compound (B).

The curable resin composition of the present invention is preferably such that the maleimide (A) is represented by the following general formula (1). (In formula (1), Ra each independently represents an alkyl group, alkoxy group or alkylthio group having 1 to 10 carbon atoms, an aryl group, aryloxy group or arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group or a hydroxyl group, and q represents an integer value of 0 to 4. When q is 2 to 4, Ra may be the same or different in the same ring. Rb each independently represents an alkyl group, alkoxy group or alkylthio group having 1 to 10 carbon atoms, an aryl group, aryloxy group or arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group or a hydroxyl group, and r represents an integer value of 0 to 3. When r is 2 to 3, Rb may be the same or different in the same ring. n is the average number of repeating units, and represents a value of 0.5 to 20).

The hardened material of the present invention is preferably formed by hardening the aforementioned hardening resin composition.

The prepreg of the present invention is preferably a semi-cured product having a reinforcing substrate and the aforementioned curable resin composition impregnated in the reinforcing substrate.

The circuit board of the present invention is preferably formed by laminating the prepreg and copper foil and then heating and pressing them.

The build-up film of the present invention preferably contains the aforementioned hardening resin composition.

The semiconductor packaging material of the present invention preferably contains the aforementioned curable resin composition.

The semiconductor device of the present invention preferably includes a hardened material obtained by heating and hardening the aforementioned semiconductor packaging material. [Effect of the invention]

According to the curable resin composition of the present invention, the cured product obtained from the curable resin composition has both excellent heat resistance and dielectric properties, and is useful in providing a curable resin composition having both of these properties, a cured product obtained from the curable resin composition, a prepreg, a circuit board, a build-up film, a semiconductor packaging material, and a semiconductor device.

The present invention is described in detail below. The present invention relates to a curable resin composition, characterized by containing a maleimide (A) having an indene skeleton and a cyanate compound (B). The maleimide (A) is preferably represented by the following general formula (1). The maleimide (A) has an indene skeleton, and has a lower proportion of polar functional groups in the structure of the maleimide (A) than conventional maleimides, and thus has excellent dielectric properties and is therefore better. Furthermore, the cured product using the conventional maleimide resin tends to be brittle and has a risk of poor brittleness resistance. However, the maleimide (A) has an indane skeleton and has excellent flexibility, and is expected to improve brittleness resistance.

In the above general formula (1), Ra each independently represents an alkyl group, alkoxy group or alkylthio group having 1 to 10 carbon atoms, an aryl group, aryloxy group or arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms (preferably 5 to 10 carbon atoms), a halogen atom, a nitro group, a hydroxyl group or a hydroxyl group, and q represents an integer value of 0 to 4. When q is 2 to 4, Ra may be the same or different in the same ring. Rb each independently represents an alkyl group, alkoxy group or alkylthio group having 1 to 10 carbon atoms, an aryl group, aryloxy group or arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group or a hydroxyl group, and r represents an integer value of 0 to 3. When r is 2 to 3, Rb may be the same or different in the same ring. n is the average number of repeating units, and represents a value of 0.5 to 20. In addition, when the aforementioned r and the aforementioned q are 0, Ra and Rb respectively refer to a hydrogen atom.

Ra of the general formula (1) is preferably an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms. By using the alkyl group having 1 to 4 carbon atoms, the planarity and crystallinity near the maleimide group are reduced, thereby achieving an ideal state in which the solvent solubility is improved while the reactivity of the maleimide group is not impaired, thereby obtaining a cured product.

In the general formula (1), q is preferably 2 to 3, more preferably 2. When q is 2, the influence of stereo hindrance is small, and the electron density on the aromatic ring is increased, which is an ideal state in the production (synthesis) of maleimide.

In the above general formula (1), it is preferred that r is 0 and Rb is a hydrogen atom. It is also preferred that r is 1 to 3 and Rb is at least one selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms. In particular, when r is 0 and Rb is a hydrogen atom, stereo hindrance is reduced when the dihydroindene skeleton in the maleimide is formed, which is advantageous for the production (synthesis) of maleimide and becomes an ideal state.

<Method for producing maleimide (A) having an indene skeleton> The following is a description of the method for producing the maleimide (A).

In the following general formula (2), each Rc independently represents a monovalent functional group selected from the group consisting of the following general formulae (3) and (4), the adjacent position of at least one of the two Rc's is a hydrogen atom, and Rb and r represent the same compounds as above.

In the following general formula (5), at least one of the ortho and para positions of the amino group is a hydrogen atom, and Ra and q are aniline or its derivatives which are the same as those described above. By reacting the compound of the above general formula (2) with the compound of the following general formula (5) in the presence of an acid catalyst, an intermediate amine compound represented by the following general formula (6) can be obtained. In addition, Ra, Rb, q, and r in the following general formula (6) are the same as those described above.

In the intermediate amine compound represented by the general formula (6), when q is 3 or less in the aniline or its derivative represented by the general formula (5), and at least two of the ortho and para positions of the amine group are hydrogen atoms, the structure of the general formula (7) having a dihydroindene skeleton is included in the structure to become the structure represented by the general formula (8). However, Ra, Rb, q and r in the general formula (8) are the same as those described above, and m is the number of repeating units, which represents an integer value of 1 to 20. In addition, the structure represented by the general formula (8) may also be included in the structure of the general formula (6).

In the characteristic indene skeleton (refer to the above-mentioned general formula (7)) of the maleimide (A) used in the present invention, in order to produce a product having a low melting point (low softening point) and a low melt viscosity and excellent handleability, the average repeating unit number n is 0.5 to 20 in terms of the average repeating unit number n (average value), preferably 0.7 to 10.0, more preferably 0.95 to 10.0, further preferably 0.98 to 9.0, further preferably 0.99 to 8.0, further preferably 1.0 to 7.0, further preferably 1.0 to 6.0. The maleimide (A) has a dihydroindene skeleton in its structure, and thus has excellent solvent solubility compared to the maleimide used so far, which is an ideal state. In addition, if the aforementioned n is less than 0.5, the content ratio of the high melting point substance in the structure of the maleimide (A) becomes high, and the solvent solubility becomes poor. Furthermore, the ratio of the high molecular weight component that contributes to flexibility becomes low, so the brittleness resistance of the obtained hardened material decreases, and there is a possibility that the flexibility and softness also decrease, which is not good. Moreover, if the aforementioned n is greater than 20, there is a possibility that the heat resistance is poor, and there is a possibility that the high molecular weight component becomes too much, and when the hardened material is formed, the fluidity decreases, and the workability is poor, which is not good. Furthermore, the value of n is preferably 0.5 to 10.0, more preferably 0.95 to 10.0, from the viewpoint of high thermal deformation temperature, high glass transition temperature, etc.

The compound represented by the general formula (2) used in the present invention (hereinafter referred to as "compound (a)") is not particularly limited, and typically, p- and m-diisopropenylbenzene, p- and m-di(α-hydroxyisopropyl)benzene, 1-(α-hydroxyisopropyl)-3-isopropenylbenzene, 1-(α-hydroxyisopropyl)-4-isopropenylbenzene or a mixture thereof are used. In addition, nucleoalkyl substituted compounds of these compounds, such as diisopropenyltoluene and di(α-hydroxyisopropyl)toluene, etc., may also be used. Furthermore, nucleohalogen substituted compounds, such as chlorodiisopropenylbenzene and chlorobis(α-hydroxyisopropyl)benzene, etc. may also be used.

In addition, examples of the compound (a) include 2-chloro-1,4-diisopropenylbenzene, 2-chloro-1,4-di(α-hydroxyisopropyl)benzene, 2-bromo-1,4-diisopropenylbenzene, 2-bromo-1,4-di(α-hydroxyisopropyl)benzene, 2-bromo-1,3-diisopropenylbenzene, 2-bromo-1,3-di(α-hydroxyisopropyl)benzene, 4-bromo-1,3-diisopropylbenzene, 4-bromo-1,3-di(α-hydroxyisopropyl)benzene, 5-bromo-1,3 ...isopropylbenzene, 2-bromo-1,3-diisopropylbenzene, 2-bromo-1,3-diisopropylbenzene, 2-bromo-1,3-diisopropylbenzene, 2-bromo-1,3-diisopropylbenzene, 2-bromo-1,3-diisopropylbenzene, 2-bromo-1,3-diisopropylbenzene, 2-bromo-1,3-diisopropylbenzene, 2-bromo-1,3-diisopropylbenzene, 2-bromo- Isopropenylbenzene, 5-bromo-1,3-bis(α-hydroxyisopropyl)benzene, 2-methoxy-1,4-diisopropenylbenzene, 2-methoxy-1,4-diisopropenylbenzene, 5-ethoxy-1,3-diisopropenylbenzene, 5-ethoxy-1,3-bis(α-hydroxyisopropyl)benzene, 2-phenoxy-1,4-diisopropenylbenzene, 2-phenoxy-1,4-di(α-hydroxyisopropyl)benzene, 2,4-diisopropenylbenzenethiol, 2,4-bis(α-hydroxyisopropyl) Benzenethiol, 2,5-diisopropenylbenzenethiol, 2,5-bis(α-hydroxyisopropyl)benzenethiol, 2-methylthio-1,4-diisopropenylbenzene, 2-methylthio-1,4-bis(α-hydroxyisopropyl)benzene, 2-phenylthio-1,3-diisopropenylbenzene, 2-phenylthio-1,3-bis(α-hydroxyisopropyl)benzene, 2-phenyl-1,4-diisopropenylbenzene, 2-phenyl-1,4-bis(α-hydroxyisopropyl)benzene, 2-cyclopentyl-1,4-diisopropenylbenzene, 2-cyclopentyl Pentyl-1,4-di(α-hydroxyisopropyl)benzene, 5-naphthyl-1,3-diisopropenylbenzene, 5-naphthyl-1,3-di(α-hydroxyisopropyl)benzene, 2-methyl-1,4-diisopropenylbenzene, 2-methyl-1,4-di(α-hydroxyisopropyl)benzene, 5-butyl-1,3-diisopropenylbenzene, 5-butyl-1,3-di(α-hydroxyisopropyl)benzene, 5-cyclohexyl-1,3-diisopropenylbenzene, 5-cyclohexyl-1,3-di(α-hydroxyisopropyl)benzene, etc.

Furthermore, the substituent contained in the aforementioned compound (a) is not particularly limited, and the compounds exemplified above can be used. However, in the case of a substituent with large stereo hindrance, stacking of the obtained maleimides is difficult to occur compared to a substituent with small stereo hindrance, and crystallization of the maleimides is difficult to occur. In other words, the solvent solubility of the maleimide is improved, which is an ideal state.

Furthermore, as the compound represented by the general formula (5) (hereinafter referred to as "compound (b)"), typically, in addition to aniline, for example, dimethylaniline, diethylaniline, diisopropylaniline, ethylmethylaniline, chloroaniline, dichloroaniline, toluidine, xylidine, phenylaniline, nitroaniline, aminophenol and cyclohexylaniline can be used. Further examples include methoxyaniline, ethoxyaniline, phenoxyaniline, naphthoxyaniline, aminothiol, methylthioaniline, ethylthioaniline and phenylthioaniline.

In addition, when the maleimide group is directly bonded to the benzene ring as in the conventional maleimide (e.g., N-phenylmaleimide), the benzene ring and the five-membered ring of maleimide are arranged on the same plane in a stable state, so it becomes easy to stack and exhibits high crystallinity. Therefore, it becomes the cause of poor solvent solubility. In contrast, in the case of the present invention, the aforementioned compound (b) is not particularly limited, and in addition to being able to use the compounds exemplified above, for example, when 2,6-dimethylaniline has a methyl group as a substituent, the benzene ring and the five-membered ring of maleimide adopt a distorted configuration due to the stereo hindrance of the methyl group, and it becomes difficult to stack, so that the crystallinity is reduced and the solvent solubility is improved, which becomes an ideal state. However, if the stereo hindrance is too large, the reactivity may be inhibited during the synthesis of maleimide. Therefore, it is preferable to use a compound (b) having an alkyl group having 2 to 4 carbon atoms.

In the method for producing the intermediate amine compound represented by the general formula (6) used in the present invention, the compound (a) and the compound (b) are added in a molar ratio of the compound (b) to the compound (a) (compound (b)/compound (a)) of preferably 0.1 to 2.0, more preferably 0.2 to 1.0, and reacted (first stage), and then the compound (b) is further added in an amount of preferably 0.5 to 20.0, more preferably 0.7 to 5.0, relative to the molar ratio of the previously added compound (a) and reacted (second stage), thereby obtaining maleimide (A) having an indane skeleton. The two-stage reaction also provides an ideal result from the viewpoint of completion of the reaction or operability. Furthermore, in the first stage of the reaction, the molar ratio of the compound (b) to the previously added compound (a) (compound (b)/compound (a)) is preferably 0.10 to 0.49, more preferably 0.15 to 0.40, and further preferably 0.20 to 0.39. Due to the wide molecular weight distribution, the content ratio of low molecular weight high melting point substances becomes lower and the ratio of high molecular weight components becomes higher, thereby obtaining an excellent solvent solubility, and further, the intermediate amine compound and maleimide which can contribute to flexibility and brittleness resistance are better.

The acid catalyst used in the above reaction includes, for example, inorganic acids such as phosphoric acid, hydrochloric acid, and sulfuric acid, organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, and fluoromethanesulfonic acid, solid acids such as activated clay, acid clay, silica alumina, zeolite, and strongly acidic ion exchange resins, and various polyacid salts. From the perspective of operability, solid acids that can be easily removed by filtering after the reaction are preferred. When other acids are used, it is preferred to neutralize with an alkali and wash with water after the reaction.

The amount of the acid catalyst mixed is 5 to 40 parts by weight relative to 100 parts by weight of the total amount of the initially charged raw materials, the aforementioned compound (a) and the aforementioned compound (b). From the viewpoint of operability and economy, 5 to 30 parts by weight is preferred. The reaction temperature is usually in the range of 100 to 300° C., and in order to suppress the formation of isomers and avoid side reactions such as thermal decomposition, 150 to 230° C. is preferred.

The reaction time is generally in the range of 2 to 48 hours in total, preferably 2 to 24 hours in total, more preferably 4 to 24 hours in total, and further preferably 4 to 12 hours in total, under the above-mentioned reaction temperature conditions, because the reaction cannot be completely carried out in a short time and side reactions such as thermal decomposition of the product may occur if the reaction time is too long. In order to reduce low molecular weight components and increase high molecular weight components, a total of 8 to 12 hours is more preferred.

In the above-mentioned method for producing the intermediate amine compound, since aniline or its derivatives can also serve as a solvent, other solvents may not necessarily be used, and a solvent may also be used. For example, in the case of a reaction system that also has a dehydration reaction, specifically, in the case of using a compound having an α-hydroxypropyl group as a raw material and reacting it, a method may be adopted in which a solvent capable of azeotropic dehydration such as toluene, xylene, or chlorobenzene is used, and after the dehydration reaction is completed, the solvent is distilled off, and then the reaction is carried out within the above-mentioned reaction temperature range.

The maleimide (A) used in the present invention can be obtained by introducing the intermediate amine compound represented by the general formula (6) obtained by the above method into a reactor, dissolving it in a suitable solvent, and reacting it in the presence of maleic anhydride and a catalyst. After the reaction, unreacted maleic anhydride and other impurities are removed by washing with water, and the solvent is removed by reducing the pressure. A dehydrating agent may be used during the reaction.

The maleimide (A) used in the present invention has a skeleton of the above-mentioned general formula (1), and includes the structure represented by the above-mentioned general formula (7) having a dihydroindene skeleton. When q is 3 or less and at least two of the ortho-positions and para-positions of the amine group are hydrogen atoms, the structure corresponding to the above-mentioned general formula (8), that is, the structure represented by the following general formula (9) is also included as the structure represented by the above-mentioned general formula (1).

In the general formula (9), Ra, Rb, q, r and m are the same as those described above.

Examples of the organic solvent used in the maleimidization reaction for synthesizing the maleimide (A) include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, and acetophenone, aprotic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, acetonitrile, and cyclobutane sulfone, cyclic ethers such as dioxane and tetrahydrofuran, esters such as ethyl acetate and butyl acetate, and aromatic solvents such as benzene, toluene, and xylene. These solvents may be used alone or in combination.

In the maleimidization reaction, the intermediate amine compound and maleic anhydride are preferably mixed in a ratio of 1 to 1.5 of maleic anhydride to the amine group equivalent of the intermediate amine compound, more preferably 1.1 to 1.2, and reacted in an organic solvent in a mass ratio of 0.5 to 50, preferably 1 to 5, to the total amount of the intermediate amine compound and maleic anhydride.

Catalysts used in the maleimidation reaction include: inorganic salts such as acetates, chlorides, bromides, sulfates, and nitrates of nickel, cobalt, sodium, calcium, iron, lithium, and manganese; inorganic acids such as phosphoric acid, hydrochloric acid, and sulfuric acid; organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, and fluoromethanesulfonic acid; solid acids such as activated clay, acidic clay, silica alumina, zeolite, and strongly acidic ion exchange resins; and various polyacid salts. Toluenesulfonic acid is particularly preferred.

Examples of the dehydrating agent used in the maleimidization reaction include lower aliphatic carboxylic anhydrides such as acetic anhydride, propionic anhydride, and butyric anhydride, oxides such as phosphorus pentoxide, calcium oxide, and barium oxide, inorganic acids such as sulfuric acid, and porous ceramics such as molecular sieves. Preferably, acetic anhydride can be used.

The amount of the catalyst and dehydrating agent used in the maleimidization reaction is not particularly limited, but is usually 0.0001 to 1.0 mol, preferably 0.001 to 0.5 mol, more preferably 0.01 to 0.3 mol, and the amount of the dehydrating agent is 1 to 3 mol, preferably 1 to 1.5 mol, relative to 1 equivalent of the amino group of the intermediate amine compound.

As the reaction conditions of the maleimidation, the intermediate amine compound and maleic anhydride are added and reacted at a temperature range of 10 to 100° C. (preferably 30 to 50° C.) for 0.5 to 12 hours (preferably 1 to 8 hours), and then the catalyst is added and reacted at a temperature range of 90 to 130° C. (preferably 105 to 120° C.) for 2 to 24 hours (preferably 4 to 10 hours). In order to reduce low molecular weight components and increase high molecular weight components, 6 to 10 hours is more preferred. After the reaction, unreacted maleic anhydride and other impurities are removed by washing with water, and low molecular weight components are reduced and high molecular weight components are increased by heat aging.

From the viewpoint of excellent low dielectric constant and low dielectric loss tangent, the maleimide (A) preferably has a molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) calculated by gel permeation chromatography (GPC) in the range of 1.0 to 10.0, more preferably 1.1 to 9.0, further preferably 1.1 to 8.0, further preferably 1.2 to 5.0, further preferably 1.2 to 4.0, further preferably 1.3 to 3.8, particularly preferably 1.3 to 3.6, and most preferably 1.3 to 3.4. Furthermore, from the GPC chart obtained from the above-mentioned GPC measurement, when the molecular weight distribution is over a wide range and the high molecular weight component is abundant, the proportion of the high molecular weight component contributing to flexibility increases, so that compared with the conventional cured product using maleimide, a cured product with suppressed brittleness and excellent flexibility and softness can be obtained, which is an ideal state.

<GPC measurement> The molecular weight distribution (Mw/Mn) of maleimide (A) was measured by gel permeation chromatography (GPC) under the following conditions. Measuring device: "HLC-8320 GPC" manufactured by Tosoh Co., Ltd. Column: Protective column "HXL-L" manufactured by Tosoh Co., Ltd. + "TSK-GEL G2000HXL" manufactured by Tosoh Co., Ltd. + "TSK-GEL G2000HXL" manufactured by Tosoh Co., Ltd. + "TSK-GEL G3000HXL" manufactured by Tosoh Co., Ltd. + "TSK-GEL G4000HXL" manufactured by Tosoh Co., Ltd. Detector: RI (differential refractometer) Data processing: "GPC Workstation EcoSEC-WorkStation" manufactured by Tosoh Co., Ltd. Measurement conditions: Column temperature 40℃ Developing solvent Tetrahydrofuran Flow rate 1.0ml/min Standard: According to the measurement manual of the aforementioned "GPC Workstation EcoSEC-WorkStation", the molecular weight uses the following monodisperse polystyrene with known molecular weight. (Polystyrene used) Tosoh Co., Ltd. "A-500" Tosoh Co., Ltd. "A-1000" Tosoh Co., Ltd. "A-2500" Tosoh Co., Ltd. "A-5000" Tosoh Co., Ltd. "F-1" Tosoh Co., Ltd. "F-2" Tosoh Co., Ltd. "F-4" Tosoh Co., Ltd. "F-10" Tosoh Co., Ltd. "F-20" Tosoh Co., Ltd. "F-40" Tosoh Co., Ltd. "F-80" Tosoh Co., Ltd. "F-128" Sample: A tetrahydrofuran solution of the maleimide obtained in the synthesis example with a resin solid content of 1.0 mass % was filtered with a microfilter (50 μl).

<Cyanate compound (B)> The curable resin composition of the present invention is characterized in that it contains a cyanate compound (B) in addition to the maleimide (A) having an indene skeleton. Since the cyanate compound (B) has excellent dielectric properties such as dielectric constant and dielectric loss tangent, it is possible to prepare a curable resin composition that can obtain a cured product that exhibits a sufficiently low dielectric loss tangent while maintaining a sufficiently low dielectric constant even in a high frequency band (high frequency region) from the MHz band to the GHz band, and thus can be used as a high-frequency molding material and is useful. Furthermore, by reacting with the maleimide (A) having a dihydroindene skeleton, it functions as a curing agent and can generate three-dimensional crosslinking, thereby obtaining a cured product having excellent heat resistance, low thermal expansion, adhesion, mechanical properties, and chemical resistance, which is an ideal state.

Examples of the cyanate compound (B) include bisphenol A type cyanate resins, bisphenol F type cyanate resins, bisphenol E type cyanate resins, bisphenol S type cyanate resins, bisphenol sulfide type cyanate resins, phenyl ether type cyanate resins, naphthyl ether type cyanate resins, biphenyl type cyanate resins, tetramethyl biphenyl type cyanate resins, polyhydroxynaphthalene type cyanate resins, phenol novolac type cyanate resins, cresol novolac type cyanate resins, triphenylmethane type cyanate resins, Cyanate resins, tetraphenylethane type cyanate resins, dicyclopentadiene-phenol addition reaction type cyanate resins, phenol aralkyl type cyanate resins, naphthol novolac type cyanate resins, naphthol aralkyl type cyanate resins, naphthol-phenol co-phenol novolac type cyanate resins, naphthol-cresol co-phenol novolac type cyanate resins, aromatic hydrocarbon formaldehyde resin modified phenol resin type cyanate resins, biphenyl modified novolac type cyanate resins, anthracene type cyanate resins, etc. These may be used alone or in combination of two or more.

In particular, from the viewpoint of obtaining a cured product having excellent heat resistance, among the above-mentioned cyanate compounds (cyanate resins), bisphenol A type cyanate resins, bisphenol F type cyanate resins, bisphenol E type cyanate resins, polyhydroxynaphthalene type cyanate resins, naphthyl ether type cyanate resins, and novolac type cyanate resins are preferably used. From the viewpoint of obtaining a cured product having excellent dielectric properties, dicyclopentadiene-phenol addition reaction type cyanate resins are preferably used.

The curable resin composition of the present invention may also contain a curing agent other than the cyanate compound (B) within the range that does not impair the curing of the present invention. In addition, the cyanate compound (B) is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, particularly preferably 80% by mass or more, and most preferably 90% by mass or more relative to the total amount of the curing agent (100% by mass).

Examples of curing agents other than the cyanate compound (B) include amine compounds, amide compounds, acid anhydride compounds, phenol compounds, polyphenylene ether compounds, compounds having a substituent containing an unsaturated double bond, diene polymers, etc. These curing agents may be used alone or in combination of two or more.

Examples of the amine compound include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF ₃ -amine complex, and guanidine derivatives.

Examples of the amide compounds include dicyandiamide and polyamide resins synthesized from a dimer of perilla oil acid and ethylenediamine.

Examples of the acid anhydride compounds include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride.

Examples of the phenolic compounds include: phenol novolac resins, cresol novolac resins, aromatic hydrocarbon formaldehyde resin modified phenol resins, dicyclopentadiene phenol addition resins, phenol aralkyl resins (Xylok resins), polyvalent phenol novolac resins synthesized from polyvalent hydroxy compounds represented by resorcinol novolac resins and formaldehyde, naphthol aralkyl resins, trihydroxymethylmethane resins, tetrahydroxyphenylethane resins, naphthol novolac resins, naphthol-phenol co-phenol novolac resins, Polyvalent phenol compounds include polyphenol resins, naphthol-cresol co-phenol formaldehyde varnish resins, biphenyl-modified phenol resins (polyvalent phenol compounds with a phenol core linked to a di-methylene group), biphenyl-modified naphthol resins (polyvalent naphthol compounds with a phenol core linked to a di-methylene group), aminotriazine-modified phenol resins (polyvalent phenol compounds with a phenol core linked to a melamine, benzoguanamine, etc.), and alkoxy-containing aromatic ring-modified phenol formaldehyde varnish resins (polyvalent phenol compounds with a phenol core and an aromatic ring containing an alkoxy group linked to formaldehyde).

The polyphenylene ether compound may have a structure represented by the following general formula (10) or (11), for example.

Rd in the above general formulae (10) and (11) can be independently exemplified by hydrogen atom, alkyl group having 1 to 5 carbon atoms, alkenyl group having 1 to 5 carbon atoms, cycloalkyl group having 3 to 5 carbon atoms, alkoxy group having 1 to 5 carbon atoms, thioether group having 1 to 5 carbon atoms, alkylcarbonyl group having 2 to 5 carbon atoms, alkoxycarbonyl group having 2 to 5 carbon atoms, alkylcarbonyloxy group having 2 to 5 carbon atoms, alkylsulfonyl group having 1 to 5 carbon atoms, etc. As the terminal structure of the above general formulae (10) and (11), there can be exemplified by groups having a hydroxyl group or a group containing a reactive double bond, etc. In addition, s is an integer value of 1 to 30, and t and u are also integer values of 1 to 30.

The aforementioned alkyl group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, dibutyl, tertiary butyl, and propyl.

The alkenyl group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include vinyl, 1-propenyl, 1-butenyl, 1-pentenyl, and isopropenyl.

The cycloalkyl group having 3 to 5 carbon atoms is not particularly limited, and examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, and methylcyclobutyl.

The alkoxy group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include methoxy, ethoxy, propoxy, isopropoxy, butoxy, and pentyloxy.

The thioether group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include methylthio, ethylthio, propylthio, isopropylthio, butylthio, and pentylthio.

The alkylcarbonyl group having 2 to 5 carbon atoms is not particularly limited, and examples thereof include methylcarbonyl, ethylcarbonyl, propylcarbonyl, isopropylcarbonyl, and butylcarbonyl.

The alkoxycarbonyl group having 2 to 5 carbon atoms is not particularly limited, and examples thereof include methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, and butoxycarbonyl.

The alkylcarbonyloxy group having 2 to 5 carbon atoms is not particularly limited, and examples thereof include methylcarbonyloxy, ethylcarbonyloxy, propylcarbonyloxy, isopropylcarbonyloxy, and butylcarbonyloxy.

The alkylsulfonyl group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl, and pentylsulfonyl.

Among them, the aforementioned Rd is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a cycloalkyl group having 3 to 5 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, further preferably a hydrogen atom, a methyl group, or an ethyl group, and particularly preferably a hydrogen atom or a methyl group.

Examples of Y in the above (11) include a divalent aromatic group derived from an aromatic compound having two phenolic hydroxyl groups.

The aromatic compound having two phenolic hydroxyl groups is not particularly limited, and examples thereof include o-catechol, resorcinol, hydroquinone, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 4,4'-biphenol, bisphenol A, bisphenol B, bisphenol BP, bisphenol C, bisphenol F, tetramethylbisphenol A, etc. Among them, hydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 4,4'-biphenol, bisphenol A, bisphenol E, and bisphenol F are preferred, and 4,4'-biphenol, bisphenol A, and tetramethylbisphenol A are more preferred.

Since the two phenolic hydroxyl groups of the aromatic compound having two phenolic hydroxyl groups form a phenyl ether bond (two oxygen atoms bonded to Y), Y becomes a divalent aromatic group derived from the aromatic compound having two phenolic hydroxyl groups.

The aforementioned compound having a substituent containing an unsaturated double bond is not particularly limited as long as it has two or more substituents containing an unsaturated bond in the molecule, and examples thereof include compounds having an allyl group, an isopropenyl group, a 1-propenyl group, an acryl group, a methacryl group, a styryl group, a styryl group, and the like as the aforementioned substituent containing an unsaturated bond.

Examples of the diene polymer include non-modified diene polymers that are not modified by polar groups. Here, the polar group refers to a functional group that affects dielectric properties, such as phenol groups, amino groups, and epoxy groups. The diene polymer is not particularly limited, and examples thereof include 1,2-polybutadiene and 1,4-polybutadiene.

As the diene polymer, a butadiene homopolymer and its derivatives in which 50% or more of the butadiene units in the polymer chain are 1,2-bonds may be used.

The curable resin composition of the present invention may also be used in combination with a curing accelerator as needed. As the aforementioned curing accelerator, various types can be used, and since the aforementioned cyanate compound (B) is used, for example, phenols, amines, Lewis acids, tertiary cobalt salts, quaternary ammonium salts, quaternary phosphonium salts, compounds containing epoxy groups, etc. can be listed. Among these, nonoxyphenol, 2,4,6-tris(dimethylaminomethyl)phenol, carboxylates of copper, lead, tin, manganese, nickel, iron, zinc, cobalt, etc., tetra-n-butoxytitanium and its polymers, pentanedionyl salts of copper, nickel, cobalt, etc., tetrabutylammonium bromide, tetrabutylphosphonium chloride, tetraphenylphosphonium tetra(methylphenyl)borate, zinc octanoate, etc. can be used. In addition, the aforementioned hardening accelerator is preferred because it has high compatibility with the aforementioned cyanate compound (B) and the hardening reaction proceeds smoothly. Moreover, among these, tetraphenylphosphonium tetra(methylphenyl)borate is particularly preferred. By using tetraphenylphosphonium tetra(methylphenyl)borate as the curing accelerator, the curing reaction proceeds faster than other curing accelerators. The amount of the curing accelerator added is preferably 0.001 to 1.00 parts by mass relative to 100 parts by mass of the cyanate compound (B).

<Preparation of curable resin composition> The curable resin composition of the present invention is characterized by containing maleimide (A) having an indene skeleton (hereinafter sometimes referred to as "(A) component") and a cyanate compound (B) (hereinafter sometimes referred to as "(B) component"). As the aforementioned (B) component, three-dimensional crosslinking can be generated by reaction with the aforementioned (A) component, and a cured product with excellent dielectric properties and heat resistance can be obtained, which is an ideal state.

The blending ratio (mass parts) of the aforementioned component (A) and the aforementioned component (B) is preferably 90:10 to 10:90, more preferably 80:20 to 20:80, and even more preferably 75:25 to 25:75. By preparing the blending ratio within the aforementioned range, heat resistance, low dielectric constant, and low dielectric loss tangent are excellent, and flexibility can be exhibited, which is preferably achieved.

The curable resin composition of the present invention may also be added with alkenyl compounds within the scope of not impairing the purpose, such as dimaleimides other than the maleimide (A), allyl ether compounds, allylamine compounds, triallyl cyanurate, alkenylphenol compounds, vinyl-containing polyolefin compounds, etc. In addition, other thermosetting resins may be appropriately blended according to the purpose, such as thermosetting polyimide resins, epoxy resins, phenol resins, active ester resins, benzophenone resins, cyanate resins, etc.

The curable resin composition of the present invention may be blended with a non-halogen flame retardant that does not substantially contain halogen atoms in order to enhance flame retardancy within the scope of not impairing the purpose. Examples of the non-halogen flame retardant include phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, and organic metal salt flame retardants, which may be used alone or in combination.

The curable resin composition of the present invention can be blended with an inorganic filler as needed. Examples of the aforementioned inorganic filler include: molten silica, crystalline silica, alumina, silicon nitride, aluminum hydroxide, and the like. When the blending amount of the aforementioned inorganic filler is set to be particularly large, it is preferred to use molten silica. The aforementioned molten silica can be used even if it is in a crushed or spherical form, but in order to increase the blending amount of molten silica and suppress the increase in the melt viscosity of the molding material, it is preferred to mainly use spherical ones. Furthermore, in order to increase the blending amount of spherical silica, it is preferred to appropriately adjust the particle size distribution of the spherical silica. The filling rate is preferably higher in view of flame retardancy, and is particularly preferably 20% by mass or more relative to the total amount of the curable resin composition. When the curable resin composition is used for the conductive paste described in detail below, a conductive filler such as silver powder or copper powder may be used.

The curable resin composition of the present invention can be added with various admixtures such as silane coupling agent, mold release agent, pigment, emulsifier, etc. as needed.

<Hardened product> The cured product of the present invention is preferably formed by subjecting the aforementioned curable resin composition to a curing reaction. The aforementioned curable resin composition can be obtained by uniformly mixing the aforementioned components, and can be easily made into a cured product by the same method as the conventionally known method. Examples of the aforementioned cured product include: laminated products, injection molded products, adhesive layers, coatings, films, and other shaped cured products.

As for the aforementioned curing (thermal curing) reaction, although it can be easily carried out without a catalyst, when it is desired to make the reaction faster, it is effective to add a polymerization initiator such as an organic peroxide or azo compound, or an alkaline catalyst such as a phosphine compound or a tertiary amine. For example, there are: benzoyl peroxide, diisopropylphenyl peroxide, azobisisobutylonitrile, triphenylphosphine, triethylamine, imidazoles, etc. The preferred blending amount is 0.05 to 5% by mass of the entire curable resin composition.

<Prepreg> The prepreg of the present invention is preferably a semi-cured material having a reinforcing substrate and the aforementioned curable resin composition impregnated in the aforementioned reinforcing substrate. As a method for making the aforementioned prepreg, a well-known method can be used, and the prepreg can be made by: impregnating the reinforcing substrate with a resin varnish obtained by dissolving (diluting) the aforementioned curable resin composition in an organic solvent, and heat-treating the reinforcing substrate impregnated with the resin varnish, thereby semi-curing (or not curing) the aforementioned curable resin composition.

As the organic solvent, for example, toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, methyl ethyl ketone (MEK), methyl isobutyl ketone, dioxane, tetrahydrofuran, etc. can be used alone or as a mixed solvent of two or more.

The reinforcing substrate for impregnation of the resin varnish is a woven fabric, a non-woven fabric, a pad, or paper made of inorganic fibers such as glass fibers, polyester fibers, polyamide fibers, or organic fibers. These can be used alone or in combination.

The mass ratio of the curable resin composition to the reinforcing base material in the prepreg is not particularly limited, but it is generally preferred that the curable resin composition (resin component in the prepreg) is 20 to 60 mass %.

The heat treatment conditions of the prepreg can be appropriately selected according to the type and amount of the organic solvent, catalyst, and various additives used, and are usually carried out at a temperature of 80 to 220°C for 3 to 30 minutes.

<Heat-resistant materials and electronic materials> The cured product obtained by the curable resin composition of the present invention can be ideally used in heat-resistant components and electronic components due to its excellent heat resistance and dielectric properties. In particular, it can be ideally used in: circuit boards, semiconductor packaging materials, semiconductor devices, build-up films, build-up substrates, adhesives, photoresists, etc. In addition, it can also be ideally used as a matrix resin for fiber-reinforced resins, and is particularly suitable as a prepreg with high heat resistance. In addition, the maleimide (A) having a dihydroindene skeleton contained in the aforementioned curable resin composition can be paintable due to its excellent solubility in various solvents. The heat-resistant components and electronic components thus obtained can be ideally used in various applications, such as, but not limited to: industrial mechanical parts, general mechanical parts, automobile, railway, vehicle parts, aerospace, aviation related parts, electronic and electrical parts, building materials, container and packaging components, daily necessities, sports and leisure products, wind power generation casing components, etc.

The following describes representative products produced using the curable resin composition of the present invention.

<Circuit board> In the present invention, the circuit board is preferably obtained by laminating the above-mentioned prepreg and copper foil and performing heat compression molding. Specifically, as a method for obtaining a circuit board from the curable resin composition of the present invention, there can be listed a method of laminating the above-mentioned prepreg by a conventional method, appropriately stacking copper foil, and heat compression molding it at 170-300°C under a pressure of 1-10MPa for 10 minutes to 3 hours.

<Semiconductor packaging material> In the present invention, the semiconductor packaging material preferably contains the aforementioned curable resin composition. Specifically, as a method for obtaining a semiconductor packaging material from the curable resin composition of the present invention, there can be listed: a method of using an extruder, a kneader, a roller, etc. as needed to fully melt and mix the aforementioned curable resin composition and a further optional component of a curing accelerator and an inorganic filler and other admixtures until they become uniform. At this time, fused silica is usually used as an inorganic filler, and when used as a high thermal conductivity semiconductor package material for power transistors and power ICs, it is preferred to use highly filled crystalline silica, alumina, silicon nitride, etc., which have a higher thermal conductivity than fused silica, or fused silica, crystalline silica, alumina, silicon nitride, etc. The filling rate is preferably 30 to 95 parts by mass of the inorganic filler per 100 parts by mass of the curable resin composition. In order to improve flame retardancy, moisture resistance, resistance to solder cracking, and reduce the linear expansion coefficient, 70 parts by mass or more is more preferred, and 80 parts by mass or more is even more preferred.

<Semiconductor device> In the present invention, the semiconductor device is preferably a hardened product obtained by heating and hardening the semiconductor packaging material. Specifically, as a semiconductor packaging molding of a semiconductor device obtained from the curable resin composition of the present invention, there can be listed a method of molding the semiconductor packaging material using an injection molding or transfer molding machine, an injection molding machine, etc., and further heating and hardening it at 50 to 250°C for 2 to 10 hours.

<Build-up substrate> As a method for obtaining a build-up substrate from the curable resin composition of the present invention, there can be listed: a method through steps 1 to 3. In step 1, the aforementioned curable resin composition appropriately mixed with rubber, filler, etc. is first applied to a circuit board having a circuit formed thereon by spray coating, curtain coating, etc., and then cured. In step 2, after drilling a predetermined through hole portion, etc., on the circuit board coated with the curable resin composition as required, it is treated with a roughening agent, and its surface is washed with hot water to form a concave-convex surface on the aforementioned substrate, and a metal plating treatment such as copper is performed. In step 3, the operations of steps 1 to 2 are repeated in sequence as required, and the resin insulation layer and the conductor layer of the specified circuit pattern are alternately added to form a build-up substrate. In addition, in the aforementioned steps, the drilling of the through hole portion is preferably performed after the outermost resin insulation layer is formed. In addition, the build-up substrate in the present invention can also be formed by forming a roughened surface by heating and pressing the copper foil with the resin composition semi-hardened on the copper foil at 170 to 300°C on the wiring substrate formed with the circuit, thereby omitting the plating treatment step to produce the build-up substrate.

<Build-up film> The build-up film of the present invention preferably contains the aforementioned hardening resin composition. As a method of obtaining the build-up film from the hardening resin composition of the present invention, for example, there can be listed a method of applying the hardening resin composition on a supporting film, drying it, and forming a resin composition layer on the supporting film. When the curable resin composition of the present invention is used in a build-up film, the film is most importantly softened under the lamination temperature conditions (usually 70°C to 140°C) in the vacuum lamination method, and has fluidity (resin flow) that enables resin filling in the through holes or through-holes of the circuit board when the circuit board is laminated. It is preferred to blend the aforementioned components in such a manner as to exhibit such characteristics. In addition, in order to prevent the occurrence of the phenomenon of locally different characteristic values due to phase separation in the obtained build-up film and circuit board (copper-clad laminate, etc.), uniform appearance is required to exhibit certain performance in any part.

Here, the diameter of the through hole of the circuit board is usually 0.1 to 0.5 mm, and the depth is usually 0.1 to 1.2 mm. It is usually better to make the resin filling possible within this range. In addition, when the two sides of the circuit board are stacked, it is expected that about 1/2 of the through hole is filled.

As a specific method for manufacturing the aforementioned layer-building film, there can be listed the following methods: after preparing a resin composition that is varnished by mixing an organic solvent, the aforementioned varnished resin composition is applied on the surface of a supporting film (Y), and the organic solvent is further dried by heating or hot air blowing to form a resin composition layer (X).

As the organic solvent used here, for example, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosol acetate, propylene glycol monomethyl ether acetate, and carbitol acetate, carbitols such as cellosol and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone are preferably used, and it is preferred to use the organic solvent in a ratio of 30 to 60 mass % of non-volatile components.

In addition, the thickness of the aforementioned resin composition layer (X) must usually be greater than the thickness of the conductor layer. The thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, so the thickness of the aforementioned resin composition layer (X) is preferably 10 to 100 μm. In addition, the aforementioned resin composition layer (X) in the present invention can be protected by a protective film described below. By protecting with a protective film, it is possible to prevent waste and the like from adhering to and damaging the surface of the resin composition layer.

The aforementioned supporting film and protective film can be listed as follows: polyolefins such as polyethylene, polypropylene, polyvinyl chloride, polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate, polycarbonate, polyimide, and further examples include: mold release paper, copper foil, aluminum foil and other metal foils. In addition, in addition to matte treatment and corona treatment, the supporting film and the protective film can be subjected to mold release treatment. The thickness of the supporting film is not particularly limited, but is generally 10 to 150 μm, preferably used in the range of 25 to 50 μm. In addition, the thickness of the protective film is preferably set to 1 to 40 μm.

The supporting film (Y) is peeled off after the circuit board is laminated or after the insulating layer is formed by heat curing. If the supporting film (Y) is peeled off after the resin composition layer constituting the build-up film is heat cured, the attachment of waste materials during the curing step can be prevented. In the case of peeling off after curing, the supporting film is usually subjected to a release treatment in advance.

In addition, a multi-layer printed circuit board can be manufactured from the build-up film obtained as described above. For example, when the resin composition layer (X) is protected by a protective film, after peeling off the resin composition layer (X), the resin composition layer (X) is directly contacted with the circuit board, for example, by vacuum lamination. The lamination method can be batch or continuous using a roller. In addition, the build-up film and the circuit board can be heated (preheated) before lamination as needed. The lamination conditions are preferably a lamination temperature of 70 to 140°C, a lamination pressure of 1 to 11 kgf/cm ² (9.8×10 ⁴ to 107.9×10 ⁴ N/m ² ), and lamination under reduced pressure of 20 mmHg (26.7 hPa) or less.

<Conductive paste> As a method for obtaining a conductive paste from the curable resin composition of the present invention, for example, there can be cited a method of dispersing conductive particles in the composition. The conductive paste can be made into a paste resin composition for circuit connection or an anisotropic conductive adhesive depending on the type of conductive particles used. [Example]

The present invention is specifically described below by way of Examples and Comparative Examples, but the following "parts" and "%" are based on mass unless otherwise specified. In addition, the softening point, amine equivalent, GPC, and FD-MS mass spectra were measured and evaluated under the following conditions.

1) Softening point Determination method: According to JIS K7234 (Universal method), the softening point (°C) of the intermediate amine compound obtained in the synthesis example shown below was measured.

2) Amine equivalent The amine equivalent of the intermediate amine compound was determined by the following method. In a 500 mL Erlenmeyer flask with a co-stopper, approximately 2.5 g of the intermediate amine compound of the sample, 7.5 g of pyridine, 2.5 g of acetic anhydride, and 7.5 g of triphenylphosphine were weighed accurately, and then a cooling tube was installed and heated to reflux in an oil bath set at 120°C for 150 minutes. After cooling, 5.0 mL of distilled water, 100 mL of propylene glycol monomethyl ether, and 75 mL of tetrahydrofuran were added, and titrated with 0.5 mol/L potassium hydroxide-ethanol solution by potentiometric titration. A blank test was performed in the same way for correction. Amine equivalent (g/eq.) = (S×2,000)/(Blank-A) S: Sample amount (g) A: Consumption of 0.5 mol/L potassium hydroxide-ethanol solution (mL) Blank: Consumption of 0.5 mol/L potassium hydroxide-ethanol solution in blank test (mL)

3) GPC measurement The following measuring apparatus and measuring conditions were used to measure and obtain the GPC graphs of the maleimide obtained in the synthesis example shown below (Figures 1 to 9). Based on the results of the above GPC graphs, the molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) and the average number of repeating units "n" of the indene skeleton in the maleimide were measured and calculated according to the number average molecular weight (Mn). Specifically, for compounds with n=0 to 4, the theoretical molecular weight and the respective measured molecular weights in GPC were plotted on a scatter plot, and an approximate straight line was drawn. The number average molecular weight (Mn) was obtained from the point indicated by the measured value Mn (1) on the straight line, and n was calculated. Measuring device: "HLC-8320 GPC" manufactured by Tosoh Co., Ltd. Column: Protective column "HXL-L" manufactured by Tosoh Co., Ltd. + "TSK-GEL G2000HXL" manufactured by Tosoh Co., Ltd. + "TSK-GEL G2000HXL" manufactured by Tosoh Co., Ltd. + "TSK-GEL G3000HXL" manufactured by Tosoh Co., Ltd. + "TSK-GEL G4000HXL" manufactured by Tosoh Co., Ltd. Detector: RI (differential refractometer) Data processing: "GPC Workstation EcoSEC-WorkStation" manufactured by Tosoh Co., Ltd. Measurement conditions: Column temperature 40℃ Developing solvent Tetrahydrofuran Flow rate 1.0ml/min Standard: According to the measurement manual of the aforementioned "GPC Workstation EcoSEC-WorkStation", the molecular weight uses the following known monodisperse polystyrene. (Polystyrene used) Tosoh Co., Ltd. "A-500" Tosoh Co., Ltd. "A-1000" Tosoh Co., Ltd. "A-2500" Tosoh Co., Ltd. "A-5000" Tosoh Co., Ltd. "F-1" Tosoh Co., Ltd. "F-2" Tosoh Co., Ltd. "F-4" Tosoh Co., Ltd. "F-10" Tosoh Co., Ltd. "F-20" Tosoh Co., Ltd. "F-40" Tosoh Co., Ltd. "F-80" Tosoh Co., Ltd. "F-128" Sample: A tetrahydrofuran solution of the maleimide obtained in the synthesis example with a resin solid content of 1.0 mass % was filtered with a microfilter (50 μl).

4) FD-MS mass spectrometry FD-MS mass spectrometry was measured using the following measuring device and measuring conditions. Measuring device: JMS-T100GC AccuTOF Measuring conditions Measuring range: m/z=4.00～2000.00 Rate of change: 51.2mA/min Final current value: 45mA Cathode voltage: -10kV Recording interval: 0.07sec

[Synthesis Example 1] Synthesis of maleimide compound A-1 (1) Synthesis of intermediate amine compound In a 1L flask equipped with a thermometer, a cooling tube, a Dean-Stark separator, and a stirrer, 48.5 g (0.4 mol) of 2,6-dimethylaniline, 272.0 g (1.4 mol) of α,α'-dihydroxy-1,3-diisopropylbenzene, 280 g of xylene, and 70 g of activated clay were added, and heated to 120°C while stirring. The temperature was further raised to 210°C while removing the distilled water with a Dean-Stark tube, and the mixture was reacted for 3 hours. Thereafter, the mixture was cooled to 140°C, 145.4 g (1.2 mol) of 2,6-dimethylaniline was added, and the temperature was raised to 220°C, and the mixture was reacted for 3 hours. After the reaction, the air was cooled to 100°C, diluted with 300 g of toluene, and the activated clay was removed by filtration. The solvent and low molecular weight substances such as unreacted products were distilled off under reduced pressure to obtain 364.1 g of an intermediate amine compound represented by the following general formula (A-1). The amine equivalent was 298 and the softening point was 70°C.

(2) Maleimidation In a 2L flask equipped with a thermometer, cooling tube, Dean-Stark separator, and stirrer, 131.8 g (1.3 mol) of maleic anhydride and 700 g of toluene were added and stirred at room temperature. Next, a mixed solution of 364.1 g of the reactant (A-1) and 175 g of DMF was added dropwise over 1 hour. After the addition of the liquid, the mixture was allowed to react at room temperature for a further 2 hours. 37.1 g of p-toluenesulfonic acid monohydrate was added, the reaction solution was heated, and the azeotropic water and toluene under reflux were cooled and separated. Only toluene was returned to the system and a dehydration reaction was carried out for 8 hours. After the air was cooled to room temperature, the brown solution was dissolved in 600 g of ethyl acetate by decompression and concentration, and washed three times with 150 g of ion exchange water and three times with 150 g of 2% sodium bicarbonate aqueous solution, and dried by adding sodium sulfate. The reaction product obtained by decompression and concentration was vacuum dried at 80°C for 4 hours to obtain 413.0 g of a product containing maleimide compound A-1. In the FD-MS mass spectrum of the maleimide compound A-1, peaks of M+=560, 718, and 876 were confirmed, and each peak corresponds to the case where n is 0, 1, and 2. In addition, when GPC was used to determine the value of the number of repeating units n in the dihydroindene skeleton portion of the maleimide A-1 (based on the number average molecular weight), the GPC chart was shown in FIG. 1 , where n=1.47 and the molecular weight distribution (Mw/Mn)=1.81.

[Synthesis Example 2] Synthesis of maleimide compound A-2 (1) Synthesis of intermediate amine compound In a 1L flask equipped with a thermometer, a cooling tube, a Dean-Stark separator, and a stirrer, 48.5 g (0.4 mol) of 2,6-dimethylaniline, 233.2 g (1.2 mol) of α,α'-dihydroxy-1,3-diisopropylbenzene, 230 g of xylene, and 66 g of activated clay were added, and heated to 120°C while stirring. The temperature was further raised to 210°C while removing the distilled water with a Dean-Stark tube, and the mixture was reacted for 3 hours. Thereafter, the mixture was cooled to 140°C, 145.4 g (1.2 mol) of 2,6-dimethylaniline was added, and the temperature was raised to 220°C, and the mixture was reacted for 3 hours. After the reaction, the air was cooled to 100°C, diluted with 300 g of toluene, and the activated clay was removed by filtration. The solvent and low molecular weight substances such as unreacted products were distilled off under reduced pressure to obtain 278.4 g of an intermediate amine compound represented by the following general formula (A-2). The amine equivalent was 294 and the softening point was 65°C.

(2) Maleimidation In a 2L flask equipped with a thermometer, cooling tube, Dean-Stark separator, and stirrer, 107.9 g (1.1 mol) of maleic anhydride and 600 g of toluene were added and stirred at room temperature. Next, a mixed solution of 278.4 g of the reactant (A-2) and 150 g of DMF was added dropwise over 1 hour. After the addition of the liquid, the mixture was allowed to react at room temperature for another 2 hours. 27.0 g of p-toluenesulfonic acid monohydrate was added, the reaction solution was heated, and the azeotropic water and toluene under reflux were cooled and separated. Only toluene was returned to the system and a dehydration reaction was carried out for 8 hours. After the air was cooled to room temperature, the brown solution was dissolved in 500 g of ethyl acetate by decompression and concentration, and washed three times with 120 g of ion exchange water and three times with 120 g of a 2% sodium bicarbonate aqueous solution. After adding sodium sulfate and drying, the reaction product obtained by decompression and concentration was vacuum dried at 80°C for 4 hours to obtain 336.8 g of a product containing maleimide compound A-2. In the FD-MS mass spectrum of the maleimide compound A-2, peaks of M+=560, 718, and 876 were confirmed, which corresponded to the cases where n was 0, 1, and 2, respectively. In addition, when GPC is used to determine the value of the number of repeating units n in the indene skeleton portion of the maleimide A-2 (based on the number average molecular weight), the GPC chart is shown in FIG. 2 , where n=1.25 and the molecular weight distribution (Mw/Mn)=3.29.

[Synthesis Example 3] Synthesis of maleimide compound A-3 (1) Synthesis of intermediate amine compound In a 2L flask equipped with a thermometer, a cooling tube, a Dean-Stark separator, and a stirrer, 48.5 g (0.4 mol) of 2,6-dimethylaniline, 388.6 g (2.0 mol) of α,α'-dihydroxy-1,3-diisopropylbenzene, 350 g of xylene, and 123 g of activated clay were added, and heated to 120°C while stirring. The temperature was further raised to 210°C while removing the distilled water with a Dean-Stark tube, and the mixture was reacted for 3 hours. Thereafter, the mixture was cooled to 140°C, 145.4 g (1.2 mol) of 2,6-dimethylaniline was added, and the temperature was raised to 220°C, and the mixture was reacted for 3 hours. After the reaction, the air was cooled to 100°C, diluted with 500 g of toluene, and the activated clay was removed by filtration. The solvent and low molecular weight substances such as unreacted products were distilled off under reduced pressure to obtain 402.1 g of an intermediate amine compound represented by the following general formula (A-3). The amine equivalent was 306 and the softening point was 65°C.

(2) Maleimidation In a 2L flask equipped with a thermometer, cooling tube, Dean-Stark separator, and stirrer, 152.1 g (1.5 mol) of maleic anhydride and 700 g of toluene were added and stirred at room temperature. Next, a mixed solution of 402.1 g of the reactant (A-3) and 200 g of DMF was added dropwise over 1 hour. After the addition was completed, the mixture was allowed to react at room temperature for a further 2 hours. 37.5 g of p-toluenesulfonic acid monohydrate was added, the reaction solution was heated, and the azeotropic water and toluene under reflux were cooled and separated. Only toluene was returned to the system and a dehydration reaction was carried out for 8 hours. After the air was cooled to room temperature, the brown solution was dissolved in 800 g of ethyl acetate by decompression and concentration, and washed three times with 200 g of ion exchange water and three times with 200 g of 2% sodium bicarbonate aqueous solution, and dried by adding sodium sulfate. The reaction product obtained by decompression and concentration was vacuum dried at 80°C for 4 hours to obtain 486.9 g of a product containing maleimide compound A-3. In the FD-MS mass spectrum of the maleimide compound A-3, peaks of M+=560, 718, and 876 were confirmed, which corresponded to the cases where n was 0, 1, and 2, respectively. In addition, when GPC was used to determine the value of the number of repeating units n in the indene skeleton portion of the maleimide A-3 (based on the number average molecular weight), the GPC chart was shown in FIG. 3 , where n=1.96 and the molecular weight distribution (Mw/Mn)=1.52.

[Synthesis Example 4] Synthesis of maleimide compound A-4 (1) Synthesis of intermediate amine compound 59.7 g (0.4 mol) of 2,6-diethylaniline, 272.0 g (1.4 mol) of α,α'-dihydroxy-1,3-diisopropylbenzene, 350 g of xylene and 94 g of activated clay were placed in a 2L flask equipped with a thermometer, a cooling tube, a Dean-Stark separator and a stirrer, and heated to 120°C while stirring. The temperature was raised to 210°C while removing the distilled water with a Dean-Stark tube, and the mixture was reacted for 3 hours. Thereafter, the mixture was cooled to 140°C, 179.1 g (1.2 mol) of 2,6-diethylaniline was added, and the temperature was raised to 220°C, and the mixture was reacted for 3 hours. After the reaction, the air was cooled to 100°C, diluted with 500 g of toluene, and the activated clay was removed by filtration. The solvent and low molecular weight substances such as unreacted products were distilled off under reduced pressure to obtain 342.1 g of an intermediate amine compound represented by the following general formula (A-4). The amine equivalent was 364 and the softening point was 47°C.

(2) Maleimidation In a 2L flask equipped with a thermometer, cooling tube, Dean-Stark separator, and stirrer, 107.9 g (1.1 mol) of maleic anhydride and 600 g of toluene were added and stirred at room temperature. Next, a mixed solution of 342.1 g of the reactant (A-4) and 180 g of DMF was added dropwise over 1 hour. After the addition of the liquid, the mixture was allowed to react at room temperature for a further 2 hours. 26.8 g of p-toluenesulfonic acid monohydrate was added, the reaction solution was heated, and the azeotropic water and toluene under reflux were cooled and separated. Only toluene was returned to the system and a dehydration reaction was carried out for 8 hours. After the air was cooled to room temperature, the brown solution was dissolved in 500 g of ethyl acetate by decompression and concentration, and washed three times with 200 g of ion exchange water and three times with 200 g of 2% sodium bicarbonate aqueous solution, and dried by adding sodium sulfate. The reaction product obtained by decompression and concentration was vacuum dried at 80°C for 4 hours to obtain 388.1 g of a product containing maleimide compound A-4. In the FD-MS mass spectrum of the maleimide compound A-4, peaks of M+=616, 774, and 932 were confirmed, which corresponded to the cases where n was 0, 1, and 2, respectively. In addition, when GPC was used to determine the value of the number of repeating units n in the indene skeleton portion of the maleimide A-4 (based on the number average molecular weight), the GPC chart was shown in FIG. 4 , where n=1.64 and the molecular weight distribution (Mw/Mn)=1.40.

[Synthesis Example 5] Synthesis of maleimide compound A-5 (1) Synthesis of intermediate amine compound In a 1L flask equipped with a thermometer, a cooling tube, a Dean-Stark separator, and a stirrer, 70.9 g (0.4 mol) of 2,6-diisopropylaniline, 272.0 g (1.4 mol) of α,α'-dihydroxy-1,3-diisopropylbenzene, 350 g of xylene, and 97 g of activated clay were added, and heated to 120°C while stirring. The temperature was further raised to 210°C while removing the distilled water with a Dean-Stark tube, and the mixture was reacted for 3 hours. Thereafter, the mixture was cooled to 140°C, 212.7 g (1.2 mol) of 2,6-diisopropylaniline was added, and the temperature was raised to 220°C, and the mixture was reacted for 3 hours. After the reaction, the air was cooled to 100°C, diluted with 500 g of toluene, and the activated clay was removed by filtration. The solvent and low molecular weight substances such as unreacted products were distilled off under reduced pressure to obtain 317.5 g of an intermediate amine compound represented by the following general formula (A-5). The amine equivalent was 366 and the softening point was 55°C.

(2) Maleimidation In a 2L flask equipped with a thermometer, cooling tube, Dean-Stark separator, and stirrer, 107.9 g (1.1 mol) of maleic anhydride and 600 g of toluene were added and stirred at room temperature. Next, a mixed solution of 317.5 g of the reactant (A-5) and 175 g of DMF was added dropwise over 1 hour. After the addition of the liquid, the mixture was allowed to react at room temperature for another 2 hours. 24.8 g of p-toluenesulfonic acid monohydrate was added, the reaction solution was heated, and the azeotropic water and toluene under reflux were cooled and separated. Only toluene was returned to the system and a dehydration reaction was carried out for 8 hours. After the air was cooled to room temperature, the brown solution was dissolved in 600 g of ethyl acetate by decompression and concentration, and washed three times with 200 g of ion exchange water and three times with 200 g of 2% sodium bicarbonate aqueous solution, and dried by adding sodium sulfate. The reaction product obtained by decompression and concentration was vacuum dried at 80°C for 4 hours to obtain 355.9 g of a product containing maleimide compound A-5. In the FD-MS mass spectrum of the maleimide compound A-5, peaks of M+=672, 830, and 988 were confirmed, which corresponded to the cases where n was 0, 1, and 2, respectively. In addition, when GPC was used to determine the value of the number of repeating units n in the indene skeleton portion of the maleimide A-5 (based on the number average molecular weight), the GPC chart was shown in FIG5 , where n=1.56 and the molecular weight distribution (Mw/Mn)=1.24.

[Synthesis Example 6] Synthesis of Maleimide Compound A-9 (1) Synthesis of Intermediate Amine Compound In the above-mentioned synthesis method of intermediate amine compound A-1, the reaction time at 210°C was changed to 6 hours, and the reaction time at 220°C was changed to 3 hours. The same operation was carried out to obtain 345.2 g of the intermediate amine compound represented by the following general formula (A-9). The amine equivalent was 348 and the softening point was 71°C.

(2) Maleimidation The same operation was performed by replacing the intermediate with A-9 from the synthesis method of the maleimide compound A-1 to obtain 407.6 g of a product containing the maleimide compound A-9. In the FD-MS mass spectrum of the maleimide compound A-9, peaks of M+=560, 718, and 876 were confirmed, and each peak corresponds to the case where n is 0, 1, and 2. In addition, when the value of the number of repeating units n in the dihydroindene skeleton part of the maleimide A-9 was determined by GPC (based on the number average molecular weight), the GPC chart is shown in Figure 6, n=2.59, and the molecular weight distribution (Mw/Mn)=1.49.

[Synthesis Example 7] Synthesis of Maleimide Compound A-10 In the synthesis method of the intermediate amine compound A-1, the reaction time at 210°C was changed to 6 hours, and the reaction time at 220°C was changed to 3 hours. The same operation was performed, and the dehydration reaction under reflux in the maleimidization reaction of the intermediate amine compound (amine equivalent weight of 347, softening point of 71°C) was set to 10 hours. The same conditions as the synthesis method of the maleimide compound A-1 were applied, thereby obtaining 415.6 g of a product containing maleimide compound A-10. In the FD-MS mass spectrum of the maleimide compound A-10, peaks of M+=560, 718, and 876 were confirmed, and the respective peaks corresponded to the cases where n was 0, 1, and 2. In addition, when GPC was used to determine the value of the number of repeating units n in the indene skeleton portion of the maleimide A-10 (based on the number average molecular weight), the GPC chart was shown in FIG. 7 , where n=2.91 and the molecular weight distribution (Mw/Mn)=1.64.

[Synthesis Example 8] Synthesis of Maleimide Compound A-11 In the synthesis method of the intermediate amine compound A-1, the reaction time at 210°C was changed to 9 hours, and the reaction time at 220°C was changed to 3 hours. The same operation was performed, and the dehydration reaction under reflux in the maleimide reaction of the intermediate amine compound (amine equivalent weight of 342, softening point of 69°C) was set to 10 hours. The same conditions as the synthesis method of the maleimide compound A-1 were applied, thereby obtaining 398.7 g of a product containing maleimide compound A-11. In the FD-MS mass spectrum of the maleimide compound A-11, peaks of M+=560, 718, and 876 were confirmed, and the respective peaks corresponded to the cases where n was 0, 1, and 2. Furthermore, when GPC was used to determine the value of the number of repeating units n in the indene skeleton portion of the maleimide A-11 (based on the number average molecular weight), the GPC chart was shown in FIG8 , where n=3.68 and the molecular weight distribution (Mw/Mn)=2.09.

[Synthesis Example 9] Synthesis of Maleimide Compound A-12 In the synthesis method of the intermediate amine compound A-1, the reaction time at 210°C was changed to 9 hours, and the reaction time at 220°C was changed to 3 hours, and the same operation was performed. For the intermediate amine compound (amine equivalent weight of 347, softening point of 70°C) synthesized, the dehydration reaction under reflux in the maleimidization reaction was set to 12 hours. The same conditions as the synthesis method of the maleimide compound A-1 were applied to obtain 422.7 g of a product containing maleimide compound A-12. In the FD-MS mass spectrum of the maleimide compound A-12, peaks of M+=560, 718, and 876 were confirmed, and the respective peaks corresponded to the cases where n was 0, 1, and 2. In addition, when GPC was used to determine the value of the number of repeating units n in the indene skeleton portion of the maleimide A-12 (based on the number average molecular weight), the GPC chart was shown in FIG. 9 , where n=4.29 and the molecular weight distribution (Mw/Mn)=3.02.

[Examples 1 to 9 and Comparative Example 1] <Solvent solubility of maleimide> The solubility of maleimide (A-1) to (A-5), (A-9) to (A-12) obtained in Synthesis Examples 1 to 9 and commercially available maleimide (A-6) (4,4'-diphenylmethane bismaleimide, "BMI-1000" manufactured by Yamato Chemical Industries, Ltd.) in toluene and methyl ethyl ketone (MEK) was evaluated. The evaluation results are shown in Table 1. As a method for evaluating solvent solubility, each maleimide obtained in the above synthesis example and comparative example was used to prepare a toluene solution and a methyl ethyl ketone (MEK) solution in such a way that the non-volatile component was 10, 20, 30, 40, 50, 60, and 70 mass %. Specifically, a small glass bottle containing each maleimide obtained in the above synthesis example and comparative example was placed at room temperature (25°C) for 60 days, and in each solution composed of each non-volatile component, the uniform dissolution (no insoluble matter) was evaluated (visually) as ○, and the non-dissolution (presence of insoluble matter) was evaluated (visually) as ×. In addition, when the non-volatile component is 20 mass % or more, it is better in practical use as long as it can be dissolved in the solvent.

[Examples 10 to 18, and Comparative Examples 2 to 4] <Preparation of a curable resin composition> The maleimides (A-1) to (A-5), (A-9) to (A-12) obtained in Synthesis Examples 1 to 9, and the comparison maleimide (A-6) (4,4'-diphenylmethane bismaleimide, "BMI-1000" manufactured by Yamato Chemical Industries, Ltd.), and the comparison maleimide (A-7) (bisphenol A diphenyl ether bismaleimide, "BMI-4000" manufactured by Yamato Chemical Industries, Ltd.) were mixed with a molten-crystal. Co., Ltd.), maleimide (A-8) for comparison (3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, "BMI-5100" manufactured by Yamato Chemical Industries, Ltd.), cyanate compound (B-1) (2,2-bis(4-cyanatophenyl)propane (manufactured by Tokyo Chemical Industry Co., Ltd.)), and curing accelerator (C-1) (tetraphenylphosphonium tetrakis(methylphenyl)borate (manufactured by Hokko Chemical Industries, Ltd.)) were blended in the ratios shown in Table 2.

<Uniformity of film appearance> In Examples 10, 15 to 18, and Comparative Examples 2 to 4, 14.81 g of methyl ethyl ketone (MEK) was mixed and dissolved in the proportions shown in Table 2 to obtain a curable resin composition. 5 g of each curable resin composition was applied to a demolding PET film (thickness after drying: 295 μm), dried (heated) at 80°C for 1 hour, and then dried (heated) at 120°C for 1 hour to prepare a film-formed product, and the appearance of the obtained film-formed product was visually confirmed. The case where the film appearance was uniform was evaluated as 0, and the case where the film appearance was non-uniform was evaluated as × (for example, the case where turbidity, insoluble matter, etc. can be confirmed). The evaluation results are shown in Table 3.

<Preparation of hardened product (molded product)> The hardened product (molded product) was prepared by subjecting the above-mentioned hardening resin composition to the following conditions. Hardening conditions: After heating at 200°C for 2 hours, further heat-hardening at 250°C for 2 hours. Thickness of hardened product (molded product) after molding: 2.4 mm For the hardened products of Examples 10 to 18 and Comparative Example 2 obtained, various physical properties and characteristics were evaluated by the following method. The evaluation results are shown in Table 4.

<Glass transition temperature (Tg)> The hardened material with a thickness of 2.4 mm was cut into a size of 5 mm in width and 54 mm in length, and the test piece was used. The test piece was subjected to a viscoelasticity measuring device (DMA: solid viscoelasticity measuring device "DMS6100" manufactured by Hitachi High-Tech Science, deformation mode: double-hold bending, measurement mode: sine wave vibration, frequency 1 Hz, heating rate 3°C/min), and the temperature at which the elastic coefficient changed to the maximum (tanδ change rate was the maximum) was evaluated as the glass transition temperature Tg (°C). In addition, from the perspective of heat resistance, the glass transition temperature Tg is preferably 250°C or higher (high Tg), and more preferably 260°C or higher.

<Thermal expansion> The 2.4mm thick hardened material was cut into pieces with a width of 5mm and a length of 5mm, and the pieces were used as test pieces. The thermal expansion coefficient CTE (ppm) in the range of 40 to 60°C was measured using a thermal analyzer ("TMA/SS6100" manufactured by SII Technologies, with a heating rate of 3°C/min). In addition, from the perspective of heat resistance and prevention of warping, the thermal expansion coefficient is preferably 60ppm or less, and more preferably 55ppm or less.

<Dielectric properties> According to JIS-C-6481, the dielectric constant and dielectric loss tangent of the test piece at 1 GHz were measured using the cavity resonance method after being stored indoors at 23°C and 50% humidity for 24 hours after absolute drying using the network analyzer "E8362C" manufactured by Agilent Technologies Co., Ltd. In addition, from the perspective of reducing the transmission loss as an electronic material, the dielectric constant is preferably 2.80 or less, and 2.70 or less is more preferably. In addition, the dielectric loss tangent is preferably 0.0050 or less, and 0.0040 or less is more preferably.

[Table 1] Solvent solubility evaluation Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 Embodiment 6 Embodiment 7 Embodiment 8 Embodiment 9 Comparison Example 1 Maleimide A-1 A-2 A-3 A-4 A-5 A-9 A-10 A-11 A-12 A-6 Toluene solution non-volatile components 10% ○ ○ ○ ○ ○ ○ ○ ○ ○ × 20% ○ ○ ○ ○ ○ ○ ○ ○ ○ × 30% ○ × ○ ○ ○ ○ ○ ○ ○ × 40% × × ○ ○ ○ ○ ○ ○ ○ × 50% × × ○ ○ ○ ○ ○ ○ ○ × 60% × × ○ × ○ ○ ○ ○ ○ × 70% × × ○ × × ○ ○ ○ ○ × MEK solution non-volatile components 10% ○ ○ ○ ○ ○ ○ ○ ○ ○ × 20% ○ ○ ○ ○ ○ ○ ○ ○ ○ × 30% ○ ○ ○ ○ ○ ○ ○ ○ ○ × 40% ○ ○ ○ ○ ○ ○ ○ ○ ○ × 50% ○ ○ ○ ○ ○ ○ ○ ○ ○ × 60% × × ○ ○ ○ ○ ○ ○ ○ × 70% × × ○ ○ ○ ○ ○ ○ ○ ×

[Table 2] Blending amount (g) Embodiment 10 Embodiment 11 Embodiment 12 Embodiment 13 Embodiment 14 Embodiment 15 Embodiment 16 Embodiment 17 Embodiment 18 Comparison Example 2 Comparison Example 3 Comparison Example 4 A-1 15.40 A-2 15.40 A-3 15.40 A-4 15.40 A-5 15.40 A-6 15.40 A-7 15.40 A-8 15.40 A-9 15.40 A-10 15.40 A-11 15.40 A-12 15.40 B-1 6.60 6.60 6.60 6.60 6.60 6.60 6.60 6.60 6.60 6.60 6.60 6.60 C-1 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22

[table 3] Embodiment 10 Embodiment 15 Embodiment 16 Embodiment 17 Embodiment 18 Comparison Example 2 Comparison Example 3 Comparison Example 4 Uniformity of film appearance ○ ○ ○ ○ ○ × × ×

[Table 4] Physical property evaluation Unit Embodiment 10 Embodiment 11 Embodiment 12 Embodiment 13 Embodiment 14 Embodiment 15 Embodiment 16 Embodiment 17 Embodiment 18 Comparison Example 2 Glass transition temperature Tg(DMA) ℃ 290 288 278 284 284 285 282 282 278 278 Coefficient of thermal expansion CTE (40～60℃) ppm 46 48 50 49 51 49 48 50 53 50 Dielectric constant (1GHz) - 2.59 2.65 2.63 2.64 2.65 2.63 2.61 2.59 2.60 2.98 Dielectric loss tangent (1GHz) - 0.0027 0.0035 0.0034 0.0036 0.0038 0.0035 0.0033 0.0032 0.0032 0.0064

From the evaluation results in Table 1 above, it can be confirmed that in Examples 1 to 9, since maleimide having an indene skeleton was used, when a toluene solution was prepared, even if the non-volatile component was 20 mass %, it was dissolved, and when a MEK solution was prepared, even if the non-volatile component was 50 mass %, it was dissolved, and the solvent solubility was excellent. On the other hand, it can be confirmed that the commercially available maleimide used in Comparative Example 1 does not have an indene skeleton in its structure, and the solvent solubility is poor.

From the evaluation results in Table 3, it can be confirmed that in Examples 10, 15 to 18, the films obtained by applying and drying the curable resin composition solution (varnish) containing the maleimide having an indole skeleton are uniform in appearance and can be used for applications such as build-up films and circuit boards (copper-clad laminates, etc.) that require uniform appearance of the obtained film. On the other hand, it can be confirmed that in Comparative Examples 2 to 4, since commercially available maleimide without an indole skeleton is used, the film is not uniform in appearance and is difficult to use for applications such as build-up films and circuit boards (copper-clad laminates, etc.).

Furthermore, from the evaluation results in Table 4 above, it can be confirmed that in Examples 10 to 18, by using a cyanate compound (B) that contributes to heat resistance and dielectric properties in addition to maleimide having an indole skeleton, the glass transition temperature is high, the heat resistance is excellent, and further the thermal expansion is low, the dielectric constant and dielectric loss tangent are suppressed to a low level, and the dielectric properties are excellent. On the other hand, it can be confirmed that in Comparative Example 2, since maleimide having an indole skeleton is not used, the dielectric constant and dielectric loss tangent cannot be suppressed to a low level relative to the examples, and the dielectric properties are also inferior. [Possibility of industrial use]

The curable resin composition of the present invention is ideal for use in heat-resistant components and electronic components, especially semiconductor packaging materials, circuit boards, build-up films, build-up substrates, adhesives, and photoresists, because the cured material has excellent heat resistance and dielectric properties. It can also be ideally used as a base resin for fiber-reinforced resins and is suitable as a high heat-resistant prepreg.

without.

Figure 1 is a GPC chart of the maleimide compound (A-1) obtained in Synthesis Example 1. Figure 2 is a GPC chart of the maleimide compound (A-2) obtained in Synthesis Example 2. Figure 3 is a GPC chart of the maleimide compound (A-3) obtained in Synthesis Example 3. Figure 4 is a GPC chart of the maleimide compound (A-4) obtained in Synthesis Example 4. Figure 5 is a GPC chart of the maleimide compound (A-5) obtained in Synthesis Example 5. Figure 6 is a GPC chart of the maleimide compound (A-9) obtained in Synthesis Example 6. Figure 7 is a GPC chart of the maleimide compound (A-10) obtained in Synthesis Example 7. Figure 8 is a GPC chart of the maleimide compound (A-11) obtained in Synthesis Example 8. FIG. 9 is a GPC chart of the maleimide compound (A-12) obtained in Synthesis Example 9.

without.

Claims (7)

A curable resin composition is characterized by containing a maleimide (A) having an indene skeleton and a cyanate compound (B), wherein the maleimide (A) is represented by the following general formula (1):

(In formula (1), Ra each independently represents an alkyl group, alkoxy group or alkylthio group having 1 to 10 carbon atoms, an aryl group, aryloxy group or arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group or a hydroxyl group, and Ra may be the same or different in the same ring; Rb each independently represents an alkyl group, alkoxy group or alkylthio group having 1 to 10 carbon atoms, an aryl group, aryloxy group or arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group or a hydroxyl group, and r represents an integer value of 0 to 3; when r is 2 to 3, Rb may be the same or different in the same ring; n is the average number of repeating units, and represents a value of 0.95 to 10.0). A hardened material, characterized by being formed by hardening the hardening resin composition as in claim 1. A prepreg characterized by having a reinforcing substrate and a semi-cured product of a curable resin composition as claimed in claim 1 impregnated in the reinforcing substrate. A circuit board characterized by being formed by heating and pressing the prepreg as in claim 3 and the copper foil laminate. A build-up film characterized by containing a hardening resin composition as claimed in claim 1. A semiconductor packaging material characterized by containing a curable resin composition as claimed in claim 1. A semiconductor device characterized by comprising a hardener for hardening the semiconductor packaging material as claimed in claim 6 by heating.