CN113748149B

CN113748149B - Curable resin composition

Info

Publication number: CN113748149B
Application number: CN202080031448.3A
Authority: CN
Inventors: 下野智弘; 冈本竜也
Original assignee: DIC Corp
Current assignee: DIC Corp
Priority date: 2019-04-26
Filing date: 2020-02-20
Publication date: 2024-05-24
Anticipated expiration: 2040-02-20
Also published as: JP7176623B2; CN113748149A; TWI844626B; KR102572049B1; JPWO2020217675A1; WO2020217675A1; KR20210137514A; TW202106798A

Abstract

Providing: curable resin composition having excellent heat resistance and dielectric characteristics as cured products thereof, prepregs, circuit boards, laminated films, semiconductor sealing materials, and semiconductor devices having these properties. The curable resin composition of the present invention is characterized by comprising: maleimide (A) having an indane skeleton, and polyphenylene ether compound (B) having a reactive double bond.

Description

Curable resin composition

Technical Field

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

Background

As a material of a circuit board for electronic devices, there is widely used: a prepreg obtained by impregnating glass cloth with a thermosetting resin such as an epoxy resin system or a BT (bismaleimide-triazine) resin system and heat-drying the glass cloth, a laminate obtained by heat-curing the prepreg, and a multilayer board obtained by heat-curing the laminate and the prepreg in combination. Among them, the semiconductor package substrate is becoming thinner, and warpage of the package substrate at the time of mounting becomes a problem, and thus in order to suppress this, a material exhibiting high heat resistance is demanded.

In addition, in recent years, the speed and frequency of signals have been increased, and it has been desired to provide a thermosetting resin composition which can provide a cured product exhibiting a sufficiently low dielectric loss tangent while maintaining a sufficiently low dielectric constant in these environments.

In particular, in various electronic material applications, particularly in advanced material applications, further improvements in properties represented by heat resistance and dielectric properties, and materials and compositions having these properties have been demanded recently.

In response to such demands, maleimide resins are attracting attention as materials having both heat resistance and low dielectric constant/low dielectric loss tangent. However, in the past, although maleimide resins have exhibited high heat resistance, their dielectric constant/dielectric loss tangent values have not reached the level required for the use of the tip material and, further, they have been inferior in handling properties due to the solubility of poorly soluble agents, and therefore, development of resins which maintain heat resistance, exhibit further low dielectric constant/low dielectric loss tangent, and are excellent in solvent solubility has been strongly desired.

Among them, as a cyanate ester material having both high dielectric characteristics and heat resistance, a resin composition obtained by mixing a phenol novolac type cyanate ester resin, a bisphenol a cyanate ester resin and a non-halogen type epoxy resin is known (see patent document 1).

However, although the heat resistance and dielectric characteristics of the cured product of the resin composition described in patent document 1 are improved to some extent, the heat resistance has not yet reached the level required in recent years.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2004-182850

Disclosure of Invention

Problems to be solved by the invention

Accordingly, the present invention has been made to solve the problems, and an object of the present invention is to provide a curable resin composition having excellent heat resistance and dielectric characteristics as a cured product thereof, and a cured product thereof, a prepreg, a circuit board, a laminate film, a semiconductor sealing material, and a semiconductor device having the above-mentioned properties.

Solution for solving the problem

Accordingly, the present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a cured product of a curable resin composition containing a maleimide (a) having an indane skeleton and a polyphenylene ether compound (B) having a reactive double bond can have a low dielectric constant and a low dielectric loss tangent, and also have excellent heat resistance, and have completed the present invention.

Specifically, the present invention relates to a curable resin composition comprising: maleimide (A) having an indane skeleton, and polyphenylene ether compound (B) having a reactive double bond.

In the curable resin composition of the present invention, the maleimide (a) is preferably represented by the following general formula (1).

( In the formula (1), ra independently represents an alkyl group, an alkoxy group or an alkylthio group having 1 to 10 carbon atoms, an aryl group, an aryloxy group or an 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 mercapto group, and q represents an integer of 0 to 4. When q is 2 to 4, ra is optionally the same or different in the same ring. Rb each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group or an alkylthio group, an aryl group having 6 to 10 carbon atoms, an aryloxy group or an arylthio group, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group or a mercapto group, and r represents an integer of 0 to 3. When r is 2-3, rb is optionally the same or different in the same ring. n is an average number of repeating units and represents a number of 0.5 to 20. )

The cured product of the present invention is preferably obtained by curing the curable resin composition.

The prepreg of the present invention preferably has a reinforcing base material and a prepreg of the curable resin composition impregnated into the reinforcing base material.

The circuit board of the present invention is preferably obtained by laminating the prepreg and the copper foil and performing thermocompression bonding molding.

The laminate film of the present invention preferably contains the curable resin composition.

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

The semiconductor device of the present invention preferably includes a cured product obtained by heat curing the semiconductor sealing material.

ADVANTAGEOUS EFFECTS OF INVENTION

The curable resin composition of the present invention is useful for providing a curable resin composition which gives a cured product from the curable resin composition excellent in both heat resistance and dielectric characteristics and has the above properties, and a cured product, prepreg, circuit board, laminated film, semiconductor sealing material and semiconductor device which are obtained from the curable resin composition.

Detailed Description

The present invention will be described in detail below.

The present invention relates to a curable resin composition comprising: maleimide (A) having an indane skeleton, and polyphenylene ether compound (B) having a reactive double bond. Among them, the maleimide (A) is preferably represented by the following general formula (1). The maleimide (a) has an indane skeleton, and therefore has a smaller proportion of polar functional groups in the structure than conventional maleimides, and is therefore preferable because of its excellent dielectric properties. Further, the cured product of the conventional maleimide resin tends to be brittle and is likely to be poor in brittleness resistance, but the maleimide (a) has an indane skeleton, and is excellent in flexibility, and improvement in brittleness resistance is also expected, and is preferable.

In the above general formula (1), ra independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group or an alkylthio group, an aryl group having 6 to 10 carbon atoms, an aryloxy group or an arylthio group, a cycloalkyl group having 3 to 10 carbon atoms (preferably 5 to 10), a halogen atom, a nitro group, a hydroxyl group or a mercapto group, and q represents an integer of 0 to 4. When q is 2 to 4, ra is optionally the same or different in the same ring. Rb each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group or an alkylthio group, an aryl group having 6 to 10 carbon atoms, an aryloxy group or an arylthio group, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group or a mercapto group, and r represents an integer of 0 to 3. When r is 2-3, rb is optionally the same or different in the same ring. n is an average number of repeating units and represents a number of 0.5 to 20. In the case where r and q are 0, ra and Rb each represent a hydrogen atom.

Ra in the general formula (1) is preferably any one 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, and the use of an alkyl group having 1 to 4 carbon atoms or the like is a preferred mode in which solvent solubility is improved due to a decrease in planarity in the vicinity of a maleimide group and a decrease in crystallinity, and a cured product can be obtained without impairing the reactivity of a maleimide group.

Q in the above general formula (1) is preferably 2 to 3, more preferably 2. When q is 2, the effect of steric hindrance is small, and the electron density on the aromatic ring is increased, which is a preferable mode in the production (synthesis) of maleimide.

Preferably, r is 0 and Rb is a hydrogen atom in the general formula (1), and r is preferably 1 to 3, rb is at least 1 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, and in particular, when r is 0 and Rb is a hydrogen atom, steric hindrance is reduced at the time of formation of an indane skeleton in maleimide, and this is preferable for production (synthesis) of maleimide.

< Method for producing maleimide (A) having indane skeleton >

The method for producing maleimide (A) will be described below.

The following general formula (2) is the following compound: rc each independently represents a monovalent functional group selected from the group consisting of the following general formulae (3) and (4), the ortho-position of at least one Rc of 2 Rc is a hydrogen atom, and Rb and r represent the same meanings as described above.

The following general formula (5) is: at least 1 of the ortho-position and para-position of the amino group is a hydrogen atom, ra and q each represent aniline or a derivative thereof having the same meaning as described above, and an intermediate amine compound represented by the following general formula (6) can be obtained by reacting a compound represented by the above general formula (2) with a compound represented by the following general formula (5) in the presence of an acid catalyst. Ra, rb, q, and r in the following general formula (6) have the same meanings as described above.

The intermediate amine compound represented by the general formula (6) has the following general formula (7) having an indane skeleton, but has the following general formula (8) when q is 3 or less and at least 2 of the ortho-position and para-position of the amino group are hydrogen atoms in the aniline represented by the general formula (5) or a derivative thereof. Wherein Ra, rb, q and r in the following formula (8) are the same as those described above, and m is the number of repeating units and represents an integer value of 1 to 20. The structure represented by the following general formula (8) may be included in the structure of the above general formula (6).

In the indane skeleton (see the above general formula (7)) which is characteristic of the maleimide (a) used in the present invention, the average repeating unit number n is 0.5 to 20, preferably 0.7 to 10.0, more preferably 0.95 to 10.0, still more preferably 0.98 to 9.0, still more preferably 0.99 to 8.0, still more preferably 1.0 to 7.0, still more preferably 1.0 to 6.0 in terms of the average repeating unit number n (average value) in order to achieve a low melting point (low softening point), a low melt viscosity and excellent handleability. By providing the structure of the maleimide (a) with an indane skeleton, the maleimide is preferable because it is superior in solvent solubility to conventionally used maleimides. When n is less than 0.5, the content of the high-melting substance in the structure of the maleimide (a) becomes high, the solvent solubility becomes poor, and the proportion of the high-molecular-weight component contributing to flexibility becomes low, so that there is a concern that the resulting cured product will be less resistant to brittleness, and further, flexibility and softness will be reduced, which is not preferable. When n exceeds 20, heat resistance may be poor, and further, high molecular weight components may be excessive, and fluidity may be lowered and handleability may be poor when a cured product is formed, which is not preferable. The value of n is preferably 0.5 to 10.0, more preferably 0.95 to 10.0, from the viewpoints of high heat distortion temperature, high glass transition temperature, and the like.

The compound represented by the above general formula (2) (hereinafter, "compound (a)") used in the present invention is not particularly limited, and p-diisopropenylbenzene and m-diisopropenylbenzene, p-bis (α -hydroxyisopropyl) benzene and m-bis (α -hydroxyisopropyl) benzene, 1- (α -hydroxyisopropyl) -3-isopropenylbenzene, 1- (α -hydroxyisopropyl) -4-isopropenylbenzene, or a mixture thereof is typically used. Further, nuclear alkyl substituents such as diisopropenyltoluene and bis (. Alpha. -hydroxyisopropyl) toluene, and further nuclear halogen substituents such as chlorodiisopropenylbenzene and chlorobis (. Alpha. -hydroxyisopropyl) benzene, may be used.

Further, as the aforementioned compound (a), for example, examples of the (a) -bis (a) -hydroxyisopropyl) benzene include 2-chloro-1, 4-diisopropenylbenzene, 2-chloro-1, 4-bis (a-hydroxyisopropyl) benzene, 2-bromo-1, 4-diisopropenylbenzene, 2-bromo-1, 3-bis (a-hydroxyisopropyl) benzene, 4-bromo-1, 3-diisopropylbenzene, 4-bromo-1, 3-bis (a-hydroxyisopropyl) benzene, 5-bromo-1, 3-diisopropenylbenzene, 5-bromo-1, 3-bis (a-hydroxyisopropyl) benzene, 2-methoxy-1, 4-diisopropenylbenzene, 2-methoxy-1, 4-bis (a-hydroxyisopropyl) benzene, 5-ethoxy-1, 3-bis (a-hydroxyisopropyl) benzene, 2-phenoxy-1, 4-diisopropenylbenzene, 2-hydroxy-1, 4-bis (a-hydroxyisopropyl) benzene, 5-diisopropenylmercaptan, 2-diisopropenylmercaptan and 2-diisopropenylmercaptan, 2-methylsulfanyl-1, 4-bis (. Alpha. -hydroxyisopropyl) benzene, 2-phenylsulfanyl-1, 3-diisopropenylbenzene, 2-phenylsulfanyl-1, 3-bis (. Alpha. -hydroxyisopropyl) benzene, 2-phenyl-1, 4-diisopropenylbenzene, 2-phenyl-1, 4-bis (. Alpha. -hydroxyisopropyl) benzene, 2-cyclopentyl-1, 4-diisopropenylbenzene, 2-cyclopentyl-1, 4-bis (. Alpha. -hydroxyisopropyl) benzene, 5-naphthyl-1, 3-diisopropenylbenzene, 5-naphthyl-1, 3-bis (. Alpha. -hydroxyisopropyl) benzene, 2-methyl-1, 4-diisopropenylbenzene, 2-methyl-1, 4-bis (. Alpha. -hydroxyisopropyl) benzene, 5-butyl-1, 3-diisopropenylbenzene, 5-butyl-1, 3-bis (. Alpha. -hydroxyisopropyl) benzene, 5-cyclohexyl-1, 3-diisopropenylbenzene, 5-cyclohexyl-1, 3-bis (. Alpha. -hydroxyisopropyl) benzene and the like.

In the case where the substituent contained in the compound (a) is not particularly limited, and the above-mentioned exemplified compound may be used, it is preferable that the resulting maleimide be less likely to be deposited on each other than the substituent having a smaller steric hindrance, and that the maleimide be less likely to be crystallized, that is, the solvent solubility of the maleimide be improved.

In addition, as the compound represented by the above general formula (5) (hereinafter, "compound (b)"), typically, dimethylaniline, diethylaniline, diisopropylaniline, ethylmethylaniline, chloroaniline, dichloroaniline, toluidine, dimethylaniline, phenylaniline, nitroaniline, aminophenol, cyclohexylaniline and the like can be used in addition to aniline. In addition, methoxyaniline, ethoxyaniline, phenoxyaniline, naphthyloxyaniline, aminothiol, methylthioaniline, ethylthioaniline and phenylthioaniline can be exemplified.

In the case where the maleimide group is directly bonded to the benzene ring as in the case of conventional maleimide (for example, N-phenylmaleimide), the benzene ring and the 5-membered ring of maleimide are stably aligned on the same plane, and therefore are easily stacked, and thus exhibit high crystallinity. Therefore, the solvent solubility is poor. In contrast, in the case of the present invention, the compound (b) is not particularly limited, and the compounds exemplified above can be used, and, for example, in the case of having a methyl group as a substituent such as 2, 6-dimethylaniline, a benzene ring and a 5-membered ring of maleimide are in a distorted conformation due to steric hindrance of the methyl group, and are less likely to accumulate, and therefore, crystallinity is reduced and solvent solubility is improved, which is a preferable embodiment. Among them, if the steric hindrance is too large, there is a concern that reactivity is hindered during synthesis of maleimide, and therefore, for example, the compound (b) having an alkyl group having 2 to 4 carbon atoms is preferably used.

In the method for producing an intermediate amine compound represented by the general formula (6) used in the present invention, after the compound (a) and the compound (b) are added and reacted in such a manner that the molar ratio of the compound (b) to the compound (a) (compound (b)/compound (a)) is preferably 0.1 to 2.0, more preferably 0.2 to 1.0 (stage 1), the compound (b) is further added and reacted in such an amount that the molar ratio of the compound (b) to the compound (a) added previously is preferably 0.5 to 20.0, more preferably 0.7 to 5.0 (stage 2), thereby obtaining maleimide (a) having an indane skeleton. The 2-stage reaction also gives preferable results in terms of completion of the reaction, handling properties, and the like. In the reaction in the 1 st stage, the compound (b) is preferably 0.10 to 0.49, more preferably 0.15 to 0.40, still more preferably 0.20 to 0.39 in terms of the molar ratio (compound (b)/compound (a)) relative to the compound (a) added previously, and the molecular weight distribution is broad, the content ratio of the low-molecular-weight high-melting-point substance is low, and the ratio of the high-molecular-weight component is high, so that an intermediate amine compound and maleimide excellent in solvent solubility and contributing to flexibility and brittleness can be obtained, is preferable.

The acid catalyst used in the above reaction may be, for example, an inorganic acid such as phosphoric acid, hydrochloric acid, sulfuric acid, oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, fluoromethanesulfonic acid and other organic acids, activated clay, acid clay, silica-alumina, zeolite, a solid acid such as a strongly acidic ion exchange resin, heteropolyacid salt and the like, and a solid acid which can be easily removed from the catalyst by filtration after the reaction is preferable from the viewpoint of the handling property, and when other acids are used, it is preferable to perform the neutralization by alkali and the washing by water after the reaction.

The amount of the acid catalyst to be blended is preferably 5 to 30 parts by mass in terms of handling property and economical efficiency, with respect to 100 parts by mass of the total amount of the compound (a) and the compound (b) of the raw materials to be initially charged. The reaction temperature is usually in the range of 100 to 300. DegreeC, preferably 150 to 230. DegreeC, in order to suppress the formation of the isomer structure and avoid side reactions such as thermal decomposition.

Since the reaction time is short and the reaction does not proceed completely and side reactions such as thermal decomposition of the product occur over a long period of time, the reaction temperature is usually in the range of 2 to 48 hours, preferably in the range of 2 to 24 hours, more preferably in the range of 4 to 24 hours, still more preferably in the range of 4 to 12 hours, in total, in order to reduce the low molecular weight component and increase the high molecular weight component, more preferably in the range of 8 to 12 hours.

In the above-described process for producing an intermediate amine compound, the aniline or its derivative serves as a solvent, and therefore, it is not necessary to use any other solvent, but a solvent may be used. For example, in the case of a reaction system that combines dehydration, specifically, in the case of reacting a compound having an α -hydroxypropyl group as a raw material, the following method can be employed: after completion of the dehydration reaction, a solvent which can be azeotropically dehydrated such as toluene, xylene or chlorobenzene is used, and the solvent is distilled off, and then the reaction is carried out at the above-mentioned reaction temperature range.

The maleimide (A) used in the present invention can be obtained as follows: the intermediate amine compound represented by the general formula (6) obtained by the above method is charged into a reactor, dissolved in an appropriate solvent, reacted in the presence of maleic anhydride and a catalyst, and after the reaction, unreacted maleic anhydride and other impurities are removed by washing with water or the like, and the solvent is removed by reducing the pressure. In addition, a dehydrating agent may be used in the reaction.

The maleimide (a) used in the present invention includes a structure represented by the general formula (7) having a skeleton of the general formula (1) and having an indane skeleton, and when q is 3 or less and at least 2 of the ortho-position and para-position of the amino group are hydrogen atoms, a structure corresponding to the general formula (8), that is, a structure represented by the general formula (9) may be included as a structure represented by the general formula (1).

Ra, rb, q, r and m in the above general formula (9) represent the same meanings as described above.

Examples of the organic solvent used in the maleinization 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-dimethylacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone, acetonitrile and sulfolane, cyclic ethers such as dioxane and tetrahydrofuran, esters such as ethyl acetate and butyl acetate, aromatic solvents such as benzene, toluene and xylene, and the like, and these solvents may be used alone or in combination.

In the maleinization reaction, the intermediate amine compound and maleic anhydride are preferably mixed in an equivalent ratio of 1 to 1.5, more preferably 1.1 to 1.2, and the reaction is preferably carried out 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.

Examples of the catalyst used in the maleinization reaction include acetates, chlorides, bromides, sulfates, nitrates, and other inorganic salts of nickel, cobalt, sodium, calcium, iron, lithium, manganese, and the like, phosphoric acid, hydrochloric acid, sulfuric acid, other inorganic acids, oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, fluoromethanesulfonic acid, other organic acids, activated clay, acid clay, silica-alumina, zeolite, solid acids such as strongly acidic ion exchange resins, heteropolyacid salts, and the like, and toluene sulfonic acid is particularly preferably used.

Examples of the dehydrating agent used in the maleinization 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, porous ceramics such as molecular sieves, and the like, and acetic anhydride is preferably used.

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

As the reaction conditions for the maleinization, the above-mentioned intermediate amine compound and maleic anhydride may be charged, and after the reaction is performed at a temperature of 10 to 100℃and preferably 30 to 50℃for 0.5 to 12 hours, preferably 1 to 8 hours, the above-mentioned catalyst is added, and the reaction is performed at a temperature of 90 to 130℃and preferably 105 to 120℃for 2 to 24 hours, preferably 4 to 10 hours, more preferably 6 to 10 hours, in order to reduce the low molecular weight component and increase the high molecular weight component. After the reaction, unreacted maleic anhydride and other impurities are removed by washing with water or the like, and the mixture is heated and aged, so that the low molecular weight component is also reduced and the high molecular weight component is increased.

The molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) of the maleimide (a) as measured by Gel Permeation Chromatography (GPC) is preferably in the range of 1.0 to 10.0, more preferably 1.1 to 9.0, still more preferably 1.1 to 8.0, still more preferably 1.2 to 5.0, still more preferably 1.2 to 4.0, still more preferably 1.3 to 3.8, particularly preferably 1.3 to 3.6, and most preferably 1.3 to 3.4, from the viewpoint of excellent low dielectric constant and low dielectric loss tangent. In addition, according to the GPC chart obtained by the GPC measurement, when the molecular weight distribution is wide and the high molecular weight component is large, the proportion of the high molecular weight component contributing to flexibility is large, so that brittleness can be suppressed as compared with a cured product using conventional maleimide, and a cured product excellent in flexibility and softness can be obtained, which is a preferable mode.

< GPC measurement >

The molecular weight distribution (Mw/Mn) of maleimide (A) was determined based on Gel Permeation Chromatography (GPC) using the following conditions.

Measurement device: HLC-8320GPC manufactured by Tosoh Co., ltd "

Column: the protective column "HXL-L" manufactured by Tosoh corporation+TSK-GEL G2000HXL manufactured by Tosoh corporation+TSK-GEL G3000HXL manufactured by Tosoh corporation+TSK-GEL G4000HXL manufactured by Tosoh corporation'

A detector: RI (differential refractometer)

And (3) data processing: GPC workstation EcoSEC-WorkStation manufactured by Tosoh Co., ltd "

Measurement conditions: column temperature 40 DEG C

Developing solvent tetrahydrofuran

Flow rate 1.0 ml/min

Standard: according to the aforementioned measurement manual of "GPC station EcoSEC-WorkStation", the following monodisperse polystyrene having a known molecular weight was used.

(Use of polystyrene)

"A-500" manufactured by Tosoh Co., ltd "

"A-1000" manufactured by Tosoh Co., ltd "

"A-2500" manufactured by Tosoh Co., ltd "

"A-5000" manufactured by Tosoh Co., ltd "

F-1 manufactured by Tosoh Co., ltd "

F-2 manufactured by Tosoh Co., ltd "

F-4 manufactured by Tosoh Co., ltd "

F-10 manufactured by Tosoh Co., ltd "

F-20 manufactured by Tosoh Co., ltd "

F-40 manufactured by Tosoh Co., ltd "

F-80 manufactured by Tosoh Co., ltd "

F-128 manufactured by Tosoh Co., ltd "

Sample: the maleimide solution obtained in the synthesis example was filtered with a microfilter to obtain a 1.0 mass% tetrahydrofuran solution in terms of resin solid content (50. Mu.l).

< Polyphenylene ether Compound (B) having reactive double bond >

The curable resin composition of the present invention is characterized by containing a polyphenylene ether compound (B) having a reactive double bond in addition to the maleimide (A) having an indane skeleton. Since the polyphenylene ether (PPE) contained in the structure of the polyphenylene ether compound (B) having a reactive double bond has excellent dielectric characteristics such as dielectric constant and dielectric loss tangent, a curable resin composition which can give a cured product exhibiting a sufficiently low dielectric loss tangent while maintaining a sufficiently low dielectric constant even in a high frequency band (high frequency region) such as MHz band to GHz band can be produced, and thus can be used as a molding material for high frequency applications, and is useful. In addition, the reaction with the maleimide (a) having an indane skeleton can function as a curing agent, and three-dimensional crosslinking can be performed, whereby a cured product excellent in heat resistance can be obtained, which is a preferred embodiment.

The polyphenylene ether compound (B) having a reactive double bond is not particularly limited as long as it is a polyphenylene ether compound having a reactive double bond in the molecule, and has a structure represented by the following general formula (10) or (11), for example.

Rd in the general formulae (10) and (11) each independently includes a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioether group having 1 to 5 carbon atoms, an alkylcarbonyl group having 2 to 5 carbon atoms, an alkoxycarbonyl group having 2 to 5 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, an alkylsulfonyl group having 1 to 5 carbon atoms, and the like. The groups having a reactive double bond in the terminal structure of the general formulae (10) and (11) include, for example, alkenyl groups having 1 to 5 carbon atoms, (meth) acryl groups, styryl groups, styrylmethyl groups, and the like. S is an integer value of 1 to 30, and t and u are also integer values of 1 to 30.

The alkyl group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, propyl and the like.

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

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

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

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

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

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

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

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

Among these, the 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, an alkyl group having 1 to 5 carbon atoms, still more preferably a hydrogen atom, a methyl group, or an ethyl group, and particularly preferably a hydrogen atom or a methyl group.

The Y in the above (11) may be a 2-valent aromatic group derived from an aromatic compound having 2 phenolic hydroxyl groups.

The aromatic compound having 2 phenolic hydroxyl groups is not particularly limited, and catechol, resorcinol, hydroquinone, 1, 4-dihydroxynaphthalene, 1, 5-dihydroxynaphthalene, 2, 6-dihydroxynaphthalene, 2, 7-dihydroxynaphthalene, 4' -biphenol, bisphenol a, bisphenol B, bisphenol BP, bisphenol C, bisphenol F, tetramethyl bisphenol a, and the like are exemplified. Among these, hydroquinone, 2, 6-dihydroxynaphthalene, 2, 7-dihydroxynaphthalene, 4 '-biphenol, bisphenol A, bisphenol E, bisphenol F are preferable, and 4,4' -biphenol, bisphenol A, and tetramethyl bisphenol A are more preferable.

Since 2 phenolic hydroxyl groups of the aromatic compound having 2 phenolic hydroxyl groups form a phenylene ether bond (2 oxygen atoms bonded to Y), Y is a 2-valent aromatic group derived from the aromatic compound having 2 phenolic hydroxyl groups.

The weight average molecular weight (Mw) of the polyphenylene ether compound (B) having a reactive double bond is preferably 1000 to 5000, more preferably 1200 to 4000, and still more preferably 1400 to 3000. In the case of the above range, a cured product having excellent balance between dielectric characteristics and heat resistance can be obtained more reliably, which is a preferred embodiment. The weight average molecular weight (Mw) herein may be a value measured by a usual molecular weight measurement method, and specifically, the above-mentioned value measured by GPC and the like are listed.

The curable resin composition of the present invention may contain a curing agent other than the polyphenylene ether compound (B) having a reactive double bond within a range that does not impair the curing of the present invention. The polyphenylene ether compound (B) having a reactive double bond is preferably 50 mass% or more, more preferably 60 mass% or more, still more preferably 70 mass% or more, particularly preferably 80 mass% or more, and most preferably 90 mass% or more, based on 100 mass% of the total amount of the curing agent.

Examples of the curing agent other than the polyphenylene ether compound (B) having a reactive double bond include amine-based compounds, amide-based compounds, acid anhydride-based compounds, phenol-based compounds, cyanate-based compounds, compounds having a substituent containing an unsaturated double bond, and diene-based polymers. These curing agents may be used alone or in combination of 2 or more.

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

Examples of the amide compound include dicyandiamide, a polyamide resin synthesized from a dimer of linolenic acid and ethylenediamine, and the like.

Examples of the acid anhydride compound 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 (Xylock resins), polyhydric phenol novolac resins composed of polyhydric hydroxyl compounds and formaldehyde represented by resorcinol novolac resins, naphthol aralkyl resins, trimethylol methane resins, tetraphenol ethane resins, naphthol novolac resins, naphthol-phenol copoly novolac resins, naphthol-cresol copoly novolac resins, biphenyl modified phenol resins (polyhydric phenol compounds in which phenol cores are linked by a bisphenol), biphenyl modified naphthol resins (polyhydric phenol compounds in which phenol cores are linked by a bisphenol), aminotriazine modified phenol resins (polyhydric phenol compounds in which phenol cores are linked by a melamine, benzoguanamine, etc.), and polyhydric phenol compounds such as alkoxy group-containing aromatic ring modified phenol novolac resins (polyhydric phenol compounds in which phenol cores and alkoxy group-containing aromatic rings are linked by a formaldehyde).

Examples of the cyanate ester compound include bisphenol a type cyanate ester resin, bisphenol F type cyanate ester resin, bisphenol E type cyanate ester resin, bisphenol S type cyanate ester resin, bisphenol thioether type cyanate ester resin, phenylene ether type cyanate ester resin, naphthylene ether type cyanate ester resin, biphenyl type cyanate ester resin, tetramethylbiphenyl type cyanate ester resin, polyhydroxy naphthalene type cyanate ester resin, phenol novolak type cyanate ester resin, cresol novolak type cyanate ester resin, triphenylmethane type cyanate ester resin, tetraphenylethane type cyanate ester resin, dicyclopentadiene-phenol addition reaction type cyanate ester resin, phenol aralkyl type cyanate ester resin, naphthol novolak type cyanate ester resin, naphthol aralkyl type cyanate ester resin, naphthol-phenol copoly type novolak type cyanate ester resin, naphthol-cresol copoly type cyanate ester resin, aromatic hydrocarbon formaldehyde resin modified phenolic resin type cyanate ester resin, biphenyl modified phenolic novolak type cyanate ester resin, anthracene type cyanate ester resin, and the like.

The unsaturated bond-containing substituent is not particularly limited as long as it is a compound having 2 or more unsaturated bond-containing substituents in the molecule, and examples thereof include compounds having allyl, isopropenyl, 1-propenyl, acryl, methacryl, styryl, styrylmethyl, and the like.

Examples of the diene polymer include unmodified diene polymers which are not modified with polar groups. Here, the polar group is a functional group that affects dielectric characteristics, and examples thereof include a phenol group, an amino group, and an epoxy group. The diene polymer is not particularly limited, and for example, 1, 2-polybutadiene, 1, 4-polybutadiene, and the like can be used.

As the diene polymer, a homopolymer of butadiene having 50% or more of butadiene units in the polymer chain as a1, 2-bond or a derivative thereof may be used.

< Preparation of curable resin composition >

The curable resin composition of the present invention is characterized by comprising: maleimide (a) having an indane skeleton (hereinafter, sometimes referred to as "(a) component") and polyphenylene ether compound (B) having a reactive double bond (hereinafter, sometimes referred to as "(B) component"). The component (B) can be three-dimensionally crosslinked by reaction with the component (a), and a cured product excellent in dielectric characteristics and heat resistance can be obtained, which is a preferred embodiment.

The blending ratio (parts by mass) of the component (A) and the component (B) is as follows: the component (B) is preferably 90: 10-10: 90, more preferably 80: 20-20: 80, further preferably 65: 35-35: 65, particularly preferably 55: 45-45: 55. by adjusting the blending ratio to the above range, heat resistance, low dielectric constant, and low dielectric loss tangent are excellent, and flexibility can be exhibited, which is preferable.

The curable resin composition of the present invention may contain an alkenyl group-containing compound, for example, bismaleimides other than the maleimide (a), allyl ether-based compounds, allylamine-based compounds, triallyl cyanurate, alkenylphenol-based compounds, vinyl-containing polyolefin compounds, and the like, within a range that does not impair the object. In addition, other thermosetting resins such as thermosetting polyimide resin, epoxy resin, phenolic resin, active ester resin, benzoxazine resin, cyanate resin and the like may be appropriately blended depending on the purpose.

In order to exhibit flame retardancy, the curable resin composition of the present invention may be blended with a non-halogen flame retardant containing substantially no halogen atoms within a range that does not impair the object. Examples of the non-halogen flame retardant include phosphorus flame retardants, nitrogen flame retardants, silicone flame retardants, inorganic flame retardants, and organometallic salt flame retardants, which may be used alone or in combination.

The curable resin composition of the present invention may be blended with an inorganic filler as needed. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, and aluminum hydroxide. In particular, when the compounding amount of the inorganic filler is increased, fused silica is preferably used. The fused silica may be in any of crushed and spherical forms, and it is preferable to mainly use spherical fused silica in order to increase the blending amount of fused silica and to suppress the increase in melt viscosity of the molding material. Further, in order to increase the blending amount of the spherical silica, the particle size distribution of the spherical silica is preferably appropriately adjusted. The filling ratio is preferably high in view of flame retardancy, and particularly preferably 20 mass% or more relative to the total amount of the curable resin composition. In the case where the curable resin composition is used for the purpose of conductive paste and the like 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 may contain various compounding agents such as a curing accelerator, a silane coupling agent, a mold release agent, a pigment, and an emulsifier, if necessary.

< Cured product >

The cured product of the present invention is preferably obtained by curing the curable resin composition. The curable resin composition can be obtained by uniformly mixing the above components, or can be easily produced into a cured product by the same method as the conventionally known method. Examples of the cured product include molded cured products such as laminates, cast molded products, adhesive layers, coating films, and films.

The curing (heat curing) reaction can be easily performed without a catalyst, and if a rapid reaction is desired, the addition of a polymerization initiator such as an organic peroxide or an azo compound, a basic catalyst such as a phosphine compound or a tertiary amine is effective. For example, benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile, triphenylphosphine, triethylamine, imidazoles, etc., are preferable as the compounding amount, and 0.05 to 5 mass% of the total curable resin composition is preferable.

< Prepreg >

The prepreg of the present invention preferably has a reinforcing base material and a prepreg of the curable resin composition impregnated into the reinforcing base material. As a method for producing the prepreg, a known method can be used, and the prepreg can be produced by impregnating a reinforcing substrate with a resin varnish obtained by dissolving (diluting) the curable resin composition in an organic solvent, and heat-treating the reinforcing substrate impregnated with the resin varnish to semi-cure (or uncured) the curable resin composition.

The organic solvent may be, for example, toluene, xylene, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, methyl Ethyl Ketone (MEK), methyl isobutyl ketone, dioxane, tetrahydrofuran, or the like, alone or as a mixed solvent of 2 or more.

The reinforcing base material impregnated with the resin varnish is a woven fabric, a nonwoven fabric, a mat, or paper made of inorganic fibers such as glass fibers, polyester fibers, and polyamide fibers, or an organic fiber, and these may 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 is preferably generally prepared so that the mass ratio of the curable resin composition in the prepreg (resin in the prepreg) is 20 to 60 mass%.

The conditions for the heat treatment of the prepreg may be appropriately selected according to the types and amounts of the organic solvent, catalyst, and various additives used, and are usually conducted at a temperature of 80 to 220℃for 3 to 30 minutes.

< Heat-resistant Material and electronic Material >

The cured product obtained from the curable resin composition of the present invention is excellent in heat resistance and dielectric properties, and therefore can be suitably used for heat-resistant members and electronic members. In particular, the composition can be suitably used for circuit boards, semiconductor sealing materials, semiconductor devices, laminated films, laminated substrates, adhesives, resist materials, and the like. In addition, the resin composition can be used as a matrix resin of a fiber-reinforced resin, and is particularly suitable as a prepreg having high heat resistance. In addition, the maleimide (a) having an indane skeleton contained in the curable resin composition exhibits excellent solubility in various solvents, and thus can be used as a coating material. The heat-resistant member and the electronic member thus obtained can be suitably used for various applications, and examples thereof include industrial machine parts, general machine parts, parts for automobiles, railways, vehicles, etc., space/aviation-related parts, electronic/electric parts, building materials, containers/packaging members, living goods, sports/leisure goods, housing members for wind power generation, etc., but are not limited to these.

Representative articles produced using the curable resin composition of the present invention will be described below by way of example.

< Circuit Board >

In the present invention, the circuit board is preferably obtained by laminating the prepreg and the copper foil and performing thermocompression bonding molding. Specifically, as a method for obtaining a circuit board from the curable resin composition of the present invention, the following methods are exemplified: the prepregs are laminated by a conventional method, and copper foil is suitably laminated, and the laminate is subjected to thermocompression bonding at 170 to 300 ℃ for 10 minutes to 3 hours under a pressure of 1 to 10 MPa.

< Semiconductor sealing Material >

In the present invention, the curable resin composition is preferably contained as the semiconductor sealing material. Specifically, as a method for obtaining a semiconductor sealing material from the curable resin composition of the present invention, the following methods are exemplified: in the curable resin composition, a curing accelerator as an optional component and a compounding agent such as an inorganic filler are further sufficiently melt-mixed until uniform by using an extruder, kneader, roll or the like as necessary. In this case, as the inorganic filler, usually, fused silica is used, and when it is used as a high heat conductive semiconductor sealing material for a power transistor or a power IC, crystalline silica, alumina, silicon nitride, or the like having a higher thermal conductivity than that of fused silica can be used, and these materials can be highly filled. The inorganic filler is preferably used in an amount of 30 to 95 parts by mass based on 100 parts by mass of the curable resin composition, and in order to improve flame retardancy, moisture resistance and weld cracking resistance and reduce the linear expansion coefficient, the inorganic filler is more preferably 70 parts by mass or more, and still more preferably 80 parts by mass or more.

< Semiconductor device >

In the present invention, the semiconductor device preferably includes a cured product obtained by heat curing the semiconductor sealing material. Specifically, the following method is exemplified as the molding of a semiconductor package to obtain a semiconductor device from the curable resin composition of the present invention: the semiconductor sealing material is cast-molded or molded by a transfer molding machine, an injection molding machine, or the like, and is further heat-cured at 50 to 250 ℃ for 2 to 10 hours.

< Laminated substrate >

The method for obtaining a laminated substrate from the curable resin composition of the present invention includes the method through steps 1 to 3. In step 1, the curable resin composition suitably blended with rubber, filler, and the like is first applied to a circuit board on which a circuit is formed by a spray coating method, curtain coating method, or the like, and then cured. In step 2, a circuit board coated with the curable resin composition is drilled with a predetermined through hole and the like, and then treated with a roughening agent, and the surface thereof is cleaned with hot water, whereby the substrate is roughened and plated with a metal such as copper, as necessary. In step 3, the operations of steps 1 to 2 are repeated in order as desired, and the resin insulating layers and the conductor layers of the predetermined circuit pattern are alternately laminated to form a laminated substrate. In the above-described step, the hole may be drilled after the formation of the outermost resin insulation layer. In the laminate substrate of the present invention, the resin-coated copper foil obtained by semi-curing the resin composition on the copper foil may be heat-pressed at 170 to 300 ℃ against the wiring substrate on which the circuit is formed, thereby forming a roughened surface, and the step of plating treatment may be omitted, thereby producing the laminate substrate.

< Laminated film >

The laminate film of the present invention preferably contains the curable resin composition. Examples of the method for obtaining a laminated film from the curable resin composition of the present invention include the following methods: the curable resin composition is applied to the support film and then dried, whereby a resin composition layer is formed on the support film. When the curable resin composition of the present invention is used in a laminate film, it is important that the film is softened under the lamination temperature conditions (usually 70 to 140 ℃) of the vacuum lamination method, and exhibits fluidity (resin flow) in which resin filling in the via holes or through holes of the circuit board can be performed while the circuit board is laminated, and in order to exhibit such characteristics, it is preferable to blend the above-mentioned components. The obtained laminated film and circuit board (copper-clad laminate or the like) are required to have a uniform appearance so as not to exhibit a phenomenon such that they locally exhibit different characteristic values due to phase separation or the like, and to exhibit predetermined performance at any position.

Here, the diameter of the through hole of the circuit board is usually 0.1 to 0.5mm, the depth is usually 0.1 to 1.2mm, and resin filling can be performed in this range. In the case of laminating both sides of the circuit board, it is preferable to fill about 1/2 of the through hole.

Specific methods for producing the laminated film include the following methods: an organic solvent is compounded to prepare a varnished resin composition, and then the varnished resin composition is applied to the surface of the support film (Y), and then the organic solvent is dried by heating, blowing with hot air, or the like to form a resin composition layer (X).

As the organic solvent used herein, for example, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, acetates such as carbitol acetate, cellosolve, aromatic hydrocarbons such as butyl carbitol, toluene, xylene, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone are preferably used, and the nonvolatile content is preferably 30 to 60 mass%.

The thickness of the resin composition layer (X) to be formed is usually not less than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70. Mu.m, the thickness of the resin composition layer (X) is preferably 10 to 100. Mu.m. The resin composition layer (X) in the present invention may be protected by a protective film described later. The protective film prevents adhesion of dust and the like to the surface of the resin composition layer and prevents damage.

Examples of the support film and the protective film include polyolefin such as polyethylene, polypropylene and polyvinyl chloride, polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate, polycarbonate, polyimide, and metal foil such as release paper, copper foil and aluminum foil. The support film and the protective film may be subjected to a matting treatment, a corona treatment, and a mold release treatment. The thickness of the support film is not particularly limited, and is usually 10 to 150. Mu.m, preferably 25 to 50. Mu.m. The thickness of the protective film is preferably 1 to 40. Mu.m.

The support film (Y) is peeled off after being laminated on a circuit board or after being heat-cured to form an insulating layer. When the support film (Y) is peeled off after the resin composition layer constituting the laminate film is heat-cured, adhesion of dust or the like in the curing step can be prevented. When peeling is performed after curing, the support film is usually subjected to a mold release treatment in advance.

The multilayer printed wiring board can be produced from the laminated film obtained as described above. For example, when the resin composition layer (X) is protected by a protective film, the resin composition layer (X) is peeled off and then laminated on one or both sides of the circuit board by, for example, vacuum lamination. The lamination may be carried out either batchwise or continuously with rolls. The laminated film and the circuit board may be heated (preheated) as needed before lamination, if necessary. The conditions for lamination are preferably such that the pressure bonding temperature (lamination temperature) is 70 to 140℃and the pressure bonding pressure is preferably 1 to 11kgf/cm ²(9.8×10⁴～107.9×10⁴N/m², and the lamination is preferably performed under reduced pressure of 20mmHg (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, a method of dispersing conductive particles in the composition is mentioned. The conductive paste may be a paste resin composition for circuit connection or an anisotropic conductive adhesive, depending on the type of conductive particles used.

Examples

The present invention will be specifically described with reference to examples and comparative examples, and "parts" and "%" hereinafter are mass-based unless otherwise specified. The softening point, amine equivalent, GPC, and FD-MS spectra were measured and evaluated under the following conditions.

1) Softening point of

Assay: the softening point (. Degree. C.) of the intermediate amine compound obtained in the synthesis example shown below was measured in accordance with JIS K7234 (ring and ball method).

2) Amine equivalent weight

The amine equivalent of the intermediate amine compound was measured by the following measurement method.

After accurately weighing about 2.5g of an intermediate amine compound, 7.5g of pyridine, 2.5g of acetic anhydride and 7.5g of triphenylphosphine as samples in a 500mL Erlenmeyer flask with a stopper, a condenser was installed and heated and refluxed in an oil bath set at 120℃for 150 minutes.

After cooling, 5.0mL of distilled water, 100mL of propylene glycol monomethyl ether, and 75mL of tetrahydrofuran were added, and titration was performed by a potentiometric titration method using a 0.5mol/L potassium hydroxide-ethanol solution. Blank tests were performed and corrections were made in the same manner.

Amine equivalent (g/eq.) = (s×2000)/(Blank-a)

S: amount of sample (g)

A: consumption of 0.5mol/L Potassium hydroxide-ethanol solution (mL)

Blank: consumption of 0.5mol/L Potassium hydroxide-ethanol solution (mL) in blank test

3) GPC measurement

The following measurement apparatus and measurement conditions were used to measure the maleimide obtained in the synthesis examples shown below, and GPC charts (FIGS. 1 to 9) were obtained. Based on the result of the GPC diagram, the molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) and the average number of repeating units "n" contributing to the indane skeleton in the maleimide are measured/calculated based on the number average molecular weight (Mn). Specifically, for the compounds having n=0 to 4, points are plotted on the scatter plot using the theoretical molecular weight and the molecular weight of each measured value in GPC, an approximate straight line is drawn, and the number average molecular weight (Mn) is calculated from the points indicated by the measured value Mn (1) on the straight line, and n is calculated.

Measurement device: HLC-8320GPC manufactured by Tosoh Co., ltd "

A detector: RI (differential refractometer)

Measurement conditions: column temperature 40 DEG C

Developing solvent tetrahydrofuran

Flow rate 1.0 ml/min

(Use of polystyrene)

"A-500" manufactured by Tosoh Co., ltd "

"A-1000" manufactured by Tosoh Co., ltd "

"A-2500" manufactured by Tosoh Co., ltd "

"A-5000" manufactured by Tosoh Co., ltd "

F-1 manufactured by Tosoh Co., ltd "

F-2 manufactured by Tosoh Co., ltd "

F-4 manufactured by Tosoh Co., ltd "

F-10 manufactured by Tosoh Co., ltd "

F-20 manufactured by Tosoh Co., ltd "

F-40 manufactured by Tosoh Co., ltd "

F-80 manufactured by Tosoh Co., ltd "

F-128 manufactured by Tosoh Co., ltd "

4) FD-MS Spectroscopy

The FD-MS spectrum was measured using the following measuring apparatus and measuring conditions.

Measurement device: JMS-T100GC AccuTOF

Measurement conditions

Measurement range: m/z=4.00-2000.00

Rate of change: 51.2 mA/min

Final current value: 45mA

Cathode voltage: -10kV

Recording interval: 0.07 seconds

Synthesis example 1 Synthesis of maleimide Compound A-1

(1) Synthesis of intermediate amine compounds

48.5G (0.4 mol) of 2, 6-dimethylaniline, 272.0g (1.4 mol) of alpha, alpha' -dihydroxy-1, 3-diisopropylbenzene, 280g of xylene and 70g of activated clay were charged into a 1L flask equipped with a thermometer, a condenser, a dean-Stark trap and a stirrer, and the mixture was heated to 120℃with stirring. The distilled water was then removed by means of a dean Stark tube and the temperature was raised to 210℃to conduct the reaction for 3 hours. Thereafter, the reaction mixture was cooled to 140℃and then charged with 145.4g (1.2 mol) of 2, 6-dimethylaniline, and the temperature was raised to 220℃to effect a reaction for 3 hours. After the reaction, air was cooled to 100℃and diluted with 300g of toluene, activated clay was removed by filtration, and low molecular weight substances such as solvents and unreacted substances were distilled off under reduced pressure, whereby 364.1g of an intermediate amine compound represented by the following general formula (A-1) was obtained. The amine equivalent was 298 and the softening point was 70 ℃.

(2) Maleinization of

Into a 2L flask equipped with a thermometer, a condenser, a dean-Stark trap, and a stirrer, 131.8g (1.3 mol) of maleic anhydride and 700g of toluene were charged, and stirred at room temperature. A mixed solution of 364.1g of the reactant (A-1) and 175g of DMF was then added dropwise over 1 hour.

After the completion of the dropwise addition, the reaction was further carried out at room temperature for 2 hours. 37.1g of p-toluenesulfonic acid monohydrate was added, the reaction mixture was heated, and azeotropic water and toluene under reflux were cooled/separated, and then toluene alone was returned to the system and dehydration reaction was carried out for 8 hours. After air cooling to room temperature, concentration under reduced pressure was performed, and the brown solution was dissolved in 600g of ethyl acetate, washed 3 times with 150g of ion-exchanged water and 3 times with 150g of 2% aqueous sodium bicarbonate solution, dried by adding sodium sulfate, and then concentrated under reduced pressure, and the obtained reaction product was dried under vacuum at 80℃for 4 hours, to obtain 413.0g of a product containing maleimide compound A-1. In the FD-MS spectrum of the maleimide compound a-1, peaks m+=560, 718, 876 were confirmed, and each peak corresponds to the case where n is 0, 1, 2. The number n of repeating units in the indane skeleton portion in maleimide a-1 was obtained by GPC (based on number average molecular weight), and as a result, the GPC diagram was shown in fig. 1, 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 compounds

48.5G (0.4 mol) of 2, 6-dimethylaniline, 233.2g (1.2 mol) of alpha, alpha' -dihydroxy-1, 3-diisopropylbenzene, 230g of xylene and 66g of activated clay were charged into a 1L flask equipped with a thermometer, a condenser, a dean-Stark trap and a stirrer, and heated to 120℃with stirring. The distilled water was then removed by means of a dean-Stark tube and the temperature was raised to 210℃to conduct the reaction for 3 hours. Thereafter, the reaction mixture was cooled to 140℃and then charged with 145.4g (1.2 mol) of 2, 6-dimethylaniline, and the temperature was raised to 220℃to effect a reaction for 3 hours. After the reaction, air was cooled to 100℃and diluted with 300g of toluene, activated clay was removed by filtration, and low molecular weight substances such as solvents and unreacted substances were distilled off under reduced pressure, whereby 278.4g of an intermediate amine compound represented by the following general formula (A-2) was obtained. The amine equivalent was 294 and the softening point was 65 ℃.

(2) Maleinization of

Into a 2L flask equipped with a thermometer, a condenser, a dean-Stark trap and a stirrer, 107.9g (1.1 mol) of maleic anhydride and 600g of toluene were charged and stirred at room temperature. A mixed solution of 278.4g of the reactant (A-2) and 150g of DMF was then added dropwise over 1 hour.

After the completion of the dropwise addition, the reaction was further carried out at room temperature for 2 hours. 27.0g of p-toluenesulfonic acid monohydrate was added, the reaction mixture was heated, and azeotropic water and toluene under reflux were cooled/separated, and then toluene alone was returned to the system and dehydration reaction was carried out for 8 hours. After air cooling to room temperature, concentration under reduced pressure was performed, the brown solution was dissolved in 500g of ethyl acetate, washed 3 times with 120g of ion-exchanged water and 3 times with 120g of 2% aqueous sodium bicarbonate solution, dried by adding sodium sulfate, and then concentrated under reduced pressure, and the obtained reaction product was dried under vacuum at 80℃for 4 hours to obtain 336.8g of a maleimide compound A-2-containing product. In the FD-MS spectrum of the maleimide compound a-2, peaks m+=560, 718, 876 were confirmed, which correspond to the cases where n was 0, 1, and 2, respectively. The number n of repeating units in the indane skeleton portion in maleimide a-2 was obtained by GPC (based on number average molecular weight), and as a result, the GPC diagram was shown in fig. 2, 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 compounds

48.5G (0.4 mol) of 2, 6-dimethylaniline, 388.6g (2.0 mol) of alpha, alpha' -dihydroxy-1, 3-diisopropylbenzene, 350g of xylene and 123g of activated clay were charged into a 2L flask equipped with a thermometer, a condenser, a dean-Stark trap and a stirrer, and heated to 120℃with stirring. The distilled water was then removed by means of a dean-Stark tube and the temperature was raised to 210℃to conduct the reaction for 3 hours. Thereafter, the reaction mixture was cooled to 140℃and then charged with 145.4g (1.2 mol) of 2, 6-dimethylaniline, and the temperature was raised to 220℃to effect a reaction for 3 hours. After the reaction, air was cooled to 100℃and diluted with 500g of toluene, activated clay was removed by filtration, and low molecular weight substances such as solvents and unreacted substances were distilled off under reduced pressure, whereby 402.1g of an intermediate amine compound represented by the following general formula (A-3) was obtained. The amine equivalent was 306 and the softening point was 65 ℃.

(2) Maleinization of

Into a 2L flask equipped with a thermometer, a condenser, a dean-Stark trap and a stirrer, 152.1g (1.5 mol) of maleic anhydride and 700g of toluene were charged and stirred at room temperature. A mixed solution of 402.1g of the reactant (A-3) and 200g of DMF was then added dropwise over 1 hour.

After the completion of the dropwise addition, the reaction was further carried out at room temperature for 2 hours. 37.5g of p-toluenesulfonic acid monohydrate was added, the reaction mixture was heated, and azeotropic water and toluene under reflux were cooled/separated, and then toluene alone was returned to the system and dehydration reaction was carried out for 8 hours. After air cooling to room temperature, concentration under reduced pressure was performed, and a brown solution was dissolved in 800g of ethyl acetate, washed 3 times with 200g of ion-exchanged water and 3 times with 200g of 2% aqueous sodium hydrogencarbonate, dried by adding sodium sulfate, and then concentrated under reduced pressure, and the obtained reaction product was dried under vacuum at 80℃for 4 hours, whereby 486.9g of a maleimide compound A-3-containing product was obtained. In the FD-MS spectrum of the maleimide compound a-3, peaks m+=560, 718, 876 were confirmed, which correspond to the cases where n was 0, 1, and 2, respectively. The value of the number n of repeating units in the indane skeleton portion in maleimide a-3 (based on the number average molecular weight) was obtained by GPC, and as a result, the GPC diagram was shown in fig. 3, 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 compounds

59.7G (0.4 mol) of 2, 6-diethylaniline, 272.0g (1.4 mol) of α, α' -dihydroxy-1, 3-diisopropylbenzene, 350g of xylene and 94g of activated clay were charged into a 2L flask equipped with a thermometer, a condenser, a dean-Stark trap and a stirrer, and the mixture was heated to 120℃with stirring. The distilled water was then removed by means of a dean-Stark tube and the temperature was raised to 210℃to conduct the reaction for 3 hours. Thereafter, the reaction mixture was cooled to 140℃and 179.1g (1.2 mol) of 2, 6-diethylaniline was introduced thereinto, followed by heating to 220℃to conduct the reaction for 3 hours. After the reaction, air was cooled to 100℃and diluted with 500g of toluene, activated clay was removed by filtration, and low molecular weight substances such as solvents and unreacted substances were distilled off under reduced pressure, whereby 342.1g of an intermediate amine compound represented by the following general formula (A-4) was obtained. The amine equivalent was 364 and the softening point was 47 ℃.

(2) Maleinization of

Into a 2L flask equipped with a thermometer, a condenser, a dean-Stark trap and a stirrer, 107.9g (1.1 mol) of maleic anhydride and 600g of toluene were charged and stirred at room temperature. A solution of 342.1g of the reaction (A-4) in 180g of DMF was then added dropwise over 1 hour.

After the completion of the dropwise addition, the reaction was further carried out at room temperature for 2 hours. 26.8g of p-toluenesulfonic acid monohydrate was added, the reaction mixture was heated, and azeotropic water and toluene under reflux were cooled/separated, and then toluene alone was returned to the system and dehydration reaction was carried out for 8 hours. After air cooling to room temperature, concentration under reduced pressure was performed, the brown solution was dissolved in 500g of ethyl acetate, washed 3 times with 200g of ion-exchanged water and 3 times with 200g of 2% aqueous sodium bicarbonate, dried by adding sodium sulfate, and then concentrated under reduced pressure, and the obtained reaction product was dried under vacuum at 80℃for 4 hours to obtain 388.1g of a maleimide compound A-4-containing product. In the FD-MS spectrum of the maleimide compound a-4, peaks m+=616, 774, 932 were confirmed, which correspond to the cases where n is 0, 1, 2, respectively. The number n of repeating units in the indane skeleton portion in maleimide a-4 was obtained by GPC (based on number average molecular weight), and as a result, the GPC diagram was shown in fig. 4, 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 compounds

70.9G (0.4 mol) of 2, 6-diisopropylaniline, 272.0g (1.4 mol) of α, α' -dihydroxy-1, 3-diisopropylbenzene, 350g of xylene and 97g of activated clay were charged into a 1L flask equipped with a thermometer, a condenser, a dean-Stark trap and a stirrer, and heated to 120℃with stirring. The distilled water was then removed by means of a dean-Stark tube and the temperature was raised to 210℃to conduct the reaction for 3 hours. Thereafter, the reaction mixture was cooled to 140℃and 212.7g (1.2 mol) of 2, 6-diisopropylaniline was charged, followed by heating to 220℃to conduct a reaction for 3 hours. After the reaction, air was cooled to 100℃and diluted with 500g of toluene, activated clay was removed by filtration, and low molecular weight substances such as solvents and unreacted substances were distilled off under reduced pressure, whereby 317.5g of an intermediate amine compound represented by the following general formula (A-5) was obtained. The amine equivalent was 366 and the softening point was 55 ℃.

(2) Maleinization of

Into a 2L flask equipped with a thermometer, a condenser, a dean-Stark trap and a stirrer, 107.9g (1.1 mol) of maleic anhydride and 600g of toluene were charged and stirred at room temperature. Then, a mixed solution of 317.5g of the reactant (A-5) and 175g of DMF was added dropwise over 1 hour.

After the completion of the dropwise addition, the reaction was further carried out at room temperature for 2 hours. 24.8g of p-toluenesulfonic acid monohydrate was added, the reaction mixture was heated, and azeotropic water and toluene under reflux were cooled/separated, and then toluene alone was returned to the system and dehydration reaction was carried out for 8 hours. After air cooling to room temperature, concentration under reduced pressure was performed, and the brown solution was dissolved in 600g of ethyl acetate, washed 3 times with 200g of ion-exchanged water and 3 times with 200g of 2% aqueous sodium bicarbonate solution, dried by adding sodium sulfate, and then concentrated under reduced pressure, and the obtained reaction product was dried under vacuum at 80℃for 4 hours to obtain 355.9g of a maleimide compound A-5-containing product. In the FD-MS spectrum of the maleimide compound a-5, peaks m+=672, 830, 988 were confirmed, which correspond to the cases where n is 0, 1, 2, respectively. The number n of repeating units in the indane skeleton portion in maleimide a-5 was obtained by GPC (based on number average molecular weight), and as a result, the GPC diagram was shown in fig. 5, n=1.56, and the molecular weight distribution (Mw/Mn) =1.24.

Synthesis example 6 Synthesis of maleimide Compound A-8

(1) Synthesis of intermediate amine compounds

In the synthesis of the intermediate amine compound A-1, the same procedure was carried out with a reaction time of 6 hours at 210℃and a reaction time of 3 hours at 220℃to obtain 345.2g of the intermediate amine compound represented by the following general formula (A-8). The amine equivalent was 348 and the softening point was 71 ℃.

(2) Maleinization of

The same procedure was carried out, except that the intermediate was replaced with A-8, according to the aforementioned synthesis method of maleimide compound A-1, to give 407.6g of a maleimide compound A-8-containing product. In the FD-MS spectrum of the maleimide compound a-8, peaks m+=560, 718, 876 were confirmed, and each peak corresponds to the case where n is 0, 1, 2. The number n of repeating units in the indane skeleton portion in maleimide a-8 was obtained by GPC (based on number average molecular weight), and as a result, the GPC diagram was shown in fig. 6, n=2.59, and the molecular weight distribution (Mw/Mn) =1.49.

Synthesis example 7 Synthesis of maleimide Compound A-9

In the synthesis of the intermediate amine compound A-1, the same procedure was carried out except that the reaction time at 210℃was changed to 6 hours and the reaction time at 220℃was changed to 3 hours, and 415.6g of a product containing the maleimide compound A-9 was obtained by setting the conditions similar to those in the synthesis of the maleimide compound A-1, except that the dehydration reaction under reflux in the maleinization reaction was carried out for 10 hours for the synthesized intermediate amine compound (amine equivalent: 347 and softening point: 71 ℃). In the FD-MS spectrum of the maleimide compound a-9, peaks m+=560, 718, 876 were confirmed, and each peak corresponds to the case where n is 0, 1, 2. The number n of repeating units in the indane skeleton portion in maleimide a-9 was obtained by GPC (based on number average molecular weight), and as a result, the GPC diagram was shown in fig. 7, n=2.91, and the molecular weight distribution (Mw/Mn) =1.64.

Synthesis example 8 Synthesis of maleimide Compound A-10

In the synthesis of the intermediate amine compound A-1, the same procedure was carried out except that the reaction time at 210℃was changed to 9 hours and the reaction time at 220℃was changed to 3 hours, and that the dehydration reaction under reflux in the maleinization reaction was carried out for 10 hours with respect to the synthesized intermediate amine compound (amine equivalent: 342 and softening point: 69 ℃ C.), thereby 398.7g of a maleimide compound A-10-containing product was obtained under the same conditions as in the synthesis of the maleimide compound A-1. In the FD-MS spectrum of the maleimide compound a-10, peaks m+=560, 718, 876 were confirmed, and each peak corresponds to the case where n is 0, 1, 2. The number n of repeating units in the indane skeleton portion in maleimide a-10 was obtained by GPC (based on number average molecular weight), and as a result, the GPC diagram was shown in fig. 8, n=3.68, and the molecular weight distribution (Mw/Mn) =2.09.

Synthesis example 9 Synthesis of maleimide Compound A-11

In the synthesis of the intermediate amine compound A-1, the same procedure was carried out except that the reaction time at 210℃was changed to 9 hours and the reaction time at 220℃was changed to 3 hours, and the dehydration reaction under reflux in the maleinization reaction was carried out for 12 hours with respect to the synthesized intermediate amine compound (amine equivalent: 347 and softening point: 70 ℃ C.), thereby obtaining 422.7g of a product containing the maleimide compound A-11 by setting the same conditions as those in the synthesis of the maleimide compound A-1. In the FD-MS spectrum of the maleimide compound a-11, peaks m+=560, 718, 876 were confirmed, and each peak corresponds to the case where n is 0, 1, 2. The number n of repeating units in the indane skeleton portion in maleimide a-11 was obtained by GPC (based on number average molecular weight), and as a result, the GPC diagram was shown in fig. 9, 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 maleimides (A-1) to (A-5), (A-8) to (A-11) obtained in Synthesis examples 1 to 9 and the commercially available maleimides (A-6) (4, 4' -diphenylmethane bismaleimide, "BMI-1000" manufactured by Kagaku Kogyo Co., ltd.) for comparison were evaluated for solubility in toluene and Methyl Ethyl Ketone (MEK), and the evaluation results are shown in Table 1.

As a method for evaluating the solvent solubility, toluene solution and Methyl Ethyl Ketone (MEK) solution were prepared so that the nonvolatile components became 10, 20, 30, 40, 50, 60, and 70 mass% using the respective maleimides obtained in the above synthesis examples and comparative examples.

Specifically, vials containing the maleimides obtained in the above synthesis examples and comparative examples were left at room temperature (25 ℃) for 60 days, and the nonvolatile components were evaluated as good when they were uniformly dissolved in the solutions (no insoluble matter), and as X (visual) when they were not dissolved. It is preferable in practice that the volatile matter is soluble in a solvent when the nonvolatile matter is 20 mass% or more.

[ Examples 10to 18 and comparative example 2]

< Preparation of curable resin composition >

The maleimides (A-1) to (A-5) and (A-8) to (A-11) obtained in Synthesis examples 1 to 9, comparative maleimide (A-6) (4, 4' -diphenylmethane bismaleimide, "BMI-1000" manufactured by Daiki Kagaku Kogyo Co., ltd.), and polyphenylene ether compound (B-1) having a reactive double bond ("SA-9000", manufactured by SABIC Co., ltd., mw: 1700) were compounded in the proportions shown in Table 2 to prepare curable resin compositions.

< Preparation of cured product (molded article) ]

The curable resin composition was subjected to the following conditions to prepare a cured product (molded product).

Curing conditions: after heating at 200℃for 2 hours, further heating and curing at 250℃for 2 hours.

Thickness of the cured product (molded product) after molding: 2.4mm

The obtained cured product was evaluated for various physical properties and characteristics by the following methods. The evaluation results are shown in table 3.

[ Examples 19 to 24, and comparative examples 3 to 4 ]

< Preparation of curable resin composition >

The maleimides (A-1), (A-8) to (A-11) and the comparative maleimide (A-7) (3, 3' -dimethyl-5, 5' -diethyl-4, 4' -diphenylmethane bismaleimide, "BMI-5100" manufactured by Dain Chemie Co., ltd.), the polyphenylene ether compound (B-1) having a reactive double bond (SA-9000, "manufactured by SABIC Co., ltd., mw: 1700), the vinylbenzyl polyphenylene ether compound (B-2) and Methyl Ethyl Ketone (MEK) obtained in Synthesis example 1 and Synthesis examples 6 to 9 were blended in the proportions shown in Table 4 to prepare curable resin compositions.

The compound (B-2) was synthesized according to example 1 of Japanese patent No. 6147538.

< Uniformity of varnish solubility and film appearance >

Whether or not the curable resin compositions of examples 19 to 24 and comparative examples 3 to 4 were uniformly dissolved (varnish solubility was confirmed) was visually confirmed. The case of uniform dissolution was evaluated as good, and the case of non-uniform dissolution or complete non-dissolution was evaluated as x (for example, the case of insoluble matter present, etc.).

Further, 5g of each curable resin composition was applied in the form of a release PET film (thickness after drying: 295 μm), dried (heated) at 80℃for 1 hour, and dried (heated) at 120℃for 1 hour, whereby a film-molded article was produced, and the appearance of the obtained film-molded article was visually confirmed. The film appearance was evaluated as uniform, and the film appearance was evaluated as non-uniform (for example, turbidity, insoluble matter, etc. could be confirmed). The evaluation results are shown in table 4.

< Glass transition temperature (Tg) >)

The cured product having a thickness of 2.4mm was cut into a size of 5mm in width and 54mm in length, and used as a test piece. The test piece was evaluated using a viscoelasticity measuring apparatus (DMA: HITACHI HIGH-TECH SCIENCE, solid viscoelasticity measuring apparatus "DMS6100", manufactured by Corporation), a deformation mode, a fixed bending at both ends, a measuring mode, a sine wave oscillation, a frequency of 1Hz, a heating rate of 3 ℃/min, and a temperature at which the elastic modulus was most changed (tan. Delta. Change rate was the greatest) as the glass transition temperature Tg (. Degree.C.). From the viewpoint of heat resistance, the glass transition temperature Tg is preferably 250 ℃ or higher (high Tg), more preferably 260 ℃ or higher.

< Thermal decomposition resistance >

The cured product having a thickness of 2.4mm was cut into small pieces, and the pieces were evaluated by using a thermogravimetric analyzer (a thermogravimetric analyzer "TGA/DSC1" manufactured by METTLER TOREDO Co.) at a temperature rise rate of 5℃per minute under a nitrogen atmosphere, and a temperature at which the weight of the cured product was reduced by 5% was set to a thermal decomposition temperature (Td 5) (DEG C).

< Thermal expansion >

The cured product having a thickness of 2.4mm was cut into a size of 5mm in width and 5mm in length, and used as a test piece. The thermal expansion coefficient CTE (ppm) was measured in the range of 40 to 60℃by a thermal analysis device (SII NanoTechnology Inc. "TMA/SS6100", temperature rise rate 3 ℃/min). From the viewpoints of heat resistance, prevention of warpage, and the like, the thermal expansion coefficient is preferably 60ppm or less, more preferably 55ppm or less.

< Dielectric Property >

The dielectric constant and dielectric loss tangent of a test piece after oven-drying and storage in a room at 23℃and 50% humidity for 24 hours were measured by a cavity method using a network analyzer "E8362C" manufactured by Agilent Technologies Co., ltd.) according to JIS-C-6481. The dielectric constant and the dielectric loss tangent are preferably 2.60 or less, more preferably 2.55 or less, from the viewpoint of reducing the transmission loss as an electronic material. The dielectric loss tangent is preferably 0.0020 or less, more preferably 0.0015 or less.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

From the evaluation results of table 1, it was confirmed that: in examples 1 to 9, since maleimide having an indane skeleton was used, the nonvolatile components were dissolved even at 20 mass% in the preparation of a toluene solution, and were dissolved even at 50 mass% in the preparation of a MEK solution, and the solvent solubility was excellent. On the other hand, it was confirmed that the commercially available maleimide used in comparative example 1 does not have an indane skeleton in the structure and has poor solvent solubility.

From the evaluation results of table 3, it was confirmed that: in examples 10 to 18, in addition to the maleimide having an indane skeleton, a polyphenylene ether compound (B) having a reactive double bond, which contains a polyphenylene ether contributing to dielectric characteristics in its structure, was used, and therefore the glass transition temperature and the thermal decomposition temperature were high, and the thermal expansion coefficient was suppressed to be small, and therefore the heat resistance and the thermal decomposition resistance were excellent. Further, it can be confirmed that: the dielectric constant and the dielectric loss tangent are also suppressed to be low, and thus the dielectric characteristics are excellent. On the other hand, for comparative example 2, it was confirmed that: in contrast to the examples, since the glass transition temperature, the thermal decomposition resistance temperature and the thermal expansion coefficient were low, the heat resistance and the thermal decomposition resistance were poor, and it was confirmed that: the dielectric constant and dielectric loss tangent cannot be suppressed to be lower than those of the examples, and the dielectric characteristics are poor.

From the evaluation results of table 4, it was confirmed that the curable resin composition solutions (varnishes) containing maleimides having indane skeletons in examples 19 to 24 were uniformly dissolved, and the appearance of films obtained by coating and drying the curable resin composition solutions (varnishes) was uniform, and the films were represented by laminated films, in particular, films requiring uniformity in appearance, and the films were also used for applications such as circuit boards (copper-clad laminates, etc.). On the other hand, confirm: in comparative examples 3 to 4, since maleimide which is commercially available and does not have an indane skeleton is used, the appearance of the film is uneven, and it is difficult to use the film for applications such as laminated films and circuit boards (copper-clad laminate, etc.).

Industrial applicability

The cured product of the curable resin composition of the present invention is excellent in heat resistance and dielectric properties, and therefore can be suitably used for heat-resistant members and electronic members, and particularly can be suitably used for semiconductor sealing materials, circuit boards, laminated films, laminated substrates, etc., adhesives, and corrosion-resistant materials. In addition, the resin composition may be suitably used as a matrix resin for a fiber-reinforced resin, and is suitably used as a prepreg having high heat resistance.

Drawings

FIG. 1 is a GPC chart of a maleimide compound (A-1) obtained in Synthesis example 1.

FIG. 2 is a GPC chart of the maleimide compound (A-2) obtained in Synthesis example 2.

FIG. 3 is a GPC chart of the maleimide compound (A-3) obtained in Synthesis example 3.

FIG. 4 is a GPC chart of the maleimide compound (A-4) obtained in Synthesis example 4.

FIG. 5 is a GPC chart of the maleimide compound (A-5) obtained in Synthesis example 5.

FIG. 6 is a GPC chart of the maleimide compound (A-8) obtained in Synthesis example 6.

FIG. 7 is a GPC chart of a maleimide compound (A-9) obtained in Synthesis example 7.

FIG. 8 is a GPC chart of a maleimide compound (A-10) obtained in Synthesis example 8.

FIG. 9 is a GPC chart of a maleimide compound (A-11) obtained in Synthesis example 9.

Claims

1. A curable resin composition characterized by comprising: a maleimide (A) having an indane skeleton, and a polyphenylene ether compound (B) having a reactive double bond,

The maleimide (A) is represented by the following general formula (1),

In the formula (1), ra independently represents an alkyl group, an alkoxy group or an alkylthio group having 1 to 10 carbon atoms, an aryl group, an aryloxy group or an 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 mercapto group, q represents an integer of 0 to 4, ra is optionally the same or different in the same ring when q is 2 to 4, rb independently represents an alkyl group, an alkoxy group or an alkylthio group having 1 to 10 carbon atoms, an aryl group, an aryloxy group or an 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 mercapto group, r represents an integer of 0 to 3, r is optionally the same or different in the same ring when r is 2 to 3, and n represents an average repeating unit number of 0.5 to 20.

2. A cured product obtained by curing the curable resin composition according to claim 1.

3. A prepreg comprising a reinforcing substrate and a prepreg impregnated with the curable resin composition according to claim 1.

4. A circuit board obtained by laminating the prepreg according to claim 3 and a copper foil and performing thermocompression bonding molding.

5. A laminated film comprising the curable resin composition according to claim 1.

6. A semiconductor sealing material comprising the curable resin composition according to claim 1.

7. A semiconductor device comprising a cured product obtained by heat curing the semiconductor sealing material according to claim 6.