JP7252301B1 - Curable resin composition, prepreg and cured product thereof - Google Patents

Abstract

Kind Code: A1 The present invention provides a curable resin composition exhibiting excellent reactivity and curability, and a cured product thereof. A curable resin composition containing a maleimide compound (A), a cyanate ester compound (B), an organometallic compound (C), and a phosphorus compound (D). [Selection figure] None

Description

TECHNICAL FIELD The present invention relates to a curable resin composition, a prepreg and a cured product thereof, and includes electrical and electronic components such as semiconductor sealing materials, printed wiring boards, and build-up laminates, carbon fiber reinforced plastics, glass fiber reinforced plastics, and the like. A lightweight high-strength material, suitable for 3D printing applications.

In recent years, due to the expansion of the fields of application of laminates on which electrical and electronic parts are mounted, the required properties are becoming more extensive and sophisticated. For example, conventionally, semiconductor chips were mainly mounted on metal lead frames, but semiconductor chips with advanced processing capabilities, such as CPUs, are increasingly mounted on laminates made of polymer materials. ing. 2. Description of the Related Art As the speed of devices such as CPUs increases and the clock frequency increases, signal propagation delay and transmission loss become problems.

Wiring boards using BT resin, which is a combination of a maleimide compound and a cyanate ester compound, have excellent dielectric properties. BT resin is used as a high-performance wiring board because it has excellent heat resistance and chemical resistance in addition to its dielectric properties.

However, in the absence of a curing accelerator, the exothermic start temperature of BT resin is located in a high temperature range of about 250°C to 300°C. can't Therefore, metal catalysts are often used as curing accelerators for BT resins. The addition of a small amount of the metal catalyst to the BT resin causes the reaction initiation temperature to shift to a lower temperature, so that it is possible to manufacture the wiring board at the temperature used in the manufacturing process.

However, if a metal catalyst is used, the BT resin cannot be completely cured, and uncured compounds remain in the system, which may adversely affect cured physical properties. If the amount of the metal catalyst added is increased for the purpose of improving curability, a large amount of triazine compound, which is a trimerized form of the cyanate ester compound, will be generated, and the maleimide compound will not be able to react, resulting in an uncured state. A maleimide compound remains. Therefore, the use of cyanate ester compounds is often restricted.

JP 2016-156002 A JP 2019-56046 A JP 2019-137841 A

In Patent Document 1, a cyanate ester compound and a maleimide compound are used, but the molding temperature is as high as 270°C. In Patent Document 2, a phenol compound is used as a curing accelerator for a mixture of a cyanate ester compound and a maleimide compound for the purpose of accelerating thermal curing of the cyanate ester compound. However, the peak onset temperature by DSC is as high as 170° C. or higher. In Patent Document 3, a phosphorus compound and a radical initiator are used in combination to cure a cyanate ester compound and a maleimide compound at a low temperature. It cannot be said that the curability is sufficient.

As described above, the thermal curing of a cyanate ester compound and a maleimide compound has the problem that the curing initiation temperature is high and it is difficult to completely cure the compound at a low temperature, and it is desired to overcome this problem.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a curable resin composition exhibiting excellent reactivity and curability, and a cured product thereof.

As a result of intensive studies to solve the above problems, the present inventors have found that a specific curable resin composition is excellent in reactivity and curability, and have completed the present invention.

That is, the present invention relates to the following [1] to [5]. In the present application, "(numerical value 1) to (numerical value 2)" indicate that upper and lower limits are included.
[1]
A curable resin composition containing a maleimide compound (A), a cyanate ester compound (B), an organometallic compound (C), and a phosphorus compound (D).
[2]
The curable resin composition according to the preceding item [1], wherein the maleimide compound (A) is represented by the following formula (1).

(In formula (1), multiple X, R ₁ , and p exist independently, and X is any of the structures represented by the following formulas (2-a) to (2-f) 1. R ₁ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aromatic group having 1 to 20 carbon atoms which may have a substituent, and p represents a real number of 1 to 3. , n is the number of repetitions, and its average value is 1<n<10.)

(In formulas (2-a) to (2-f), * represents a bond to a benzene ring. Multiple R ₂ , m, q, and r exist independently, and R ₂ is a hydrogen atom. , an alkyl group having 1 to 20 carbon atoms, or an aromatic group having 1 to 20 carbon atoms which may have a substituent, m is a real number of 1 to 50, q is 1 to 4, r is a real number of 1 to 3 represents.)
[3]
The curable resin composition according to [1] or [2] above, wherein the cyanate ester compound (B) is 0.3 to 3.5 equivalents relative to 1 equivalent of the maleimide compound (A).
[4]
The curable resin composition according to any one of the preceding items [1] to [3], which contains a zinc atom as the organometallic compound (C).
[5]
A prepreg in which the curable resin composition according to any one of the preceding items [1] to [4] is held by a sheet-like fiber base material.
[6]
A cured product obtained by curing the curable resin composition according to any one of [1] to [4] above or the prepreg according to [5] above.

The curable resin composition of the present invention has excellent reactivity and curability.

1 is a GPC chart of Synthesis Example 1. FIG. 2 is a GPC chart of Synthesis Example 2. FIG. 4 is a DMA chart of Examples 1 and 2 and Comparative Examples 1 and 2;

The curable resin composition of the invention is described below.
The curable resin composition of the present invention contains a maleimide compound (A), a cyanate ester compound (B), an organometallic compound (C) and a phosphorus compound (D).

Examples of the maleimide compound (A) include 4,4′-diphenylmethanebismaleimide, polyphenylmethanemaleimide, m-phenylenebismaleimide, 2,2′-bis[4-(4-maleimidophenoxy)phenyl]propane, and 3,3′. -dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 4,4'-diphenyletherbismaleimide, 4,4'-diphenylsulfonebismaleimide, Examples thereof include 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, etc. Maleimide compounds represented by the following formula (1) are preferred.

(In formula (1), multiple X, R ₁ , and p exist independently, and X is any of the structures represented by the following formulas (2-a) to (2-f) 1. R ₁ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aromatic group having 1 to 20 carbon atoms which may have a substituent, and p represents a real number of 1 to 3. , n is the number of repetitions, and its average value is 1<n<10.)

(In formulas (2-a) to (2-f), * represents a bond to a benzene ring. Multiple R ₂ , m, q, and r exist independently, and R ₂ is a hydrogen atom. , an alkyl group having 1 to 20 carbon atoms, or an aromatic group having 1 to 20 carbon atoms which may have a substituent, m is a real number of 1 to 50, q is 1 to 4, r is a real number of 1 to 3 represents.)

In formula (1), R ₁ is preferably a hydrogen atom.

In formulas (2-a) to (2-f), R ₂ is preferably a hydrogen atom.

X is solvent solubility and compatibility, and from the viewpoint of heat resistance of the cured product obtained by curing the curable resin composition of the present invention formula (2-b), formula (2-c), formula (2- e), more preferably represented by formula (2-c) or formula (2-e).

In the above formula (1), the value of n is calculated from the number average molecular weight obtained by measurement of the maleimide compound by gel permeation chromatography (GPC, detector: RI), or from the area ratio of each of the separated peaks. can do. In the above formula (1), when n=1, the solubility in a solvent is low, and when n is 10 or more, flowability during molding deteriorates, and properties as a cured product cannot be fully exhibited.

The softening point of the maleimide compound represented by the formula (1) is preferably 50° C. to 150° C., more preferably 80° C. to 120° C., still more preferably 90° C. to 120° C., particularly preferably 95° C. °C to 120 °C. Also, the melt viscosity at 150° C. is 0.05 to 100 Pa·s, preferably 0.1 to 40 Pa·s.

The maleimide compound represented by the formula (1) is preferably a maleimide compound represented by the following formula (3) or (4).

(In formula (3), n is the number of repetitions, and the average value is 1<n<10.)

(In formula (4), n is the number of repetitions, and the average value is 1<n<10.)

The maleimide compound represented by the formula (3) may be a commercially available product or a manufactured product. Commercially available products include MIR-3000-70MT (manufactured by Nippon Kayaku Co., Ltd.). When it is produced, the method for producing the maleimide compound represented by the formula (3) is not particularly limited, and any known method known as a method for synthesizing maleimide compounds may be used for production. When producing the maleimide compound of the above formula (3), the compound of the following formula (5) is required as a precursor thereof. and a dihalogenomethyl compound or a dialkoxymethyl compound are described, and the following formula ( A compound of 5) is obtained.

(In formula (5), n is the number of repetitions, and the average value is 1<n<10.)

Bishalogenomethylbiphenyls or bisalkoxymethylbiphenyls used include 4,4′-bis(chloromethyl)biphenyl, 4,4′-bis(bromomethyl)biphenyl, 4,4′-bis(fluoromethyl) biphenyl, 4,4'-bis(iodomethyl)biphenyl, 4,4'-dimethoxymethylbiphenyl, 4,4'-diethoxymethylbiphenyl, 4,4'-dipropoxymethylbiphenyl, 4,4'-diisopropoxy methylbiphenyl, 4,4'-diisobutoxymethylbiphenyl, 4,4'-dibutoxymethylbiphenyl, 4,4'-di-tert-butoxymethylbiphenyl and the like. These may be used alone or in combination of two or more. The amount of bishalogenomethylbiphenyls or bisalkoxymethylbiphenyls to be used is preferably 0.05 to 0.8 mol, more preferably 0.1 to 0.6 mol, per 1 mol of aniline used.

In the reaction, if necessary, an acidic catalyst such as hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, zinc chloride, ferric chloride, aluminum chloride, p-toluenesulfonic acid, methanesulfonic acid, etc. may be used. These may be used alone or in combination of two or more. The amount of the catalyst used is preferably 0.1 to 0.8 mol, more preferably 0.5 to 0.7 mol, per 1 mol of aniline. It becomes difficult, and too little slows down the progress of the reaction. The reaction may be carried out using an organic solvent such as toluene, xylene, or the like, if necessary, or may be carried out without a solvent. For example, after adding an acidic catalyst to a mixed solution of anilines and a solvent, water is removed from the system by azeotropy when the catalyst contains water. Thereafter, preferably 40 to 100° C., more preferably 50 to 80° C., bishalogenomethylbiphenyls or bisalkoxymethylbiphenyls are added for preferably 1 to 5 hours, more preferably 2 to 4 hours, and then the solvent is added. is removed from the system, the temperature is raised to preferably 180 to 240° C., more preferably 190 to 220° C., and the reaction is carried out for preferably 5 to 30 hours, more preferably 10 to 20 hours. After the reaction is completed, neutralize the acidic catalyst with an alkaline aqueous solution, add a non-water-soluble organic solvent to the oil layer, repeat washing until the wastewater becomes neutral, and distill off excess aniline and organic solvent under heating and reduced pressure. Although it is not mentioned in Japanese Patent Publication No. 8-16151 or Japanese Patent No. 5030297 that the compound of the formula (5) is obtained by the above, diphenylamine, which is a by-product at this stage, depends on the catalyst amount, raw material usage ratio, Although it varies depending on the temperature, time, etc., it is usually contained in the resin in an amount of 2 to 10% by weight. Diphenylamine cannot be removed under the conditions for distilling off aniline. Diphenylamine can be removed at least by blowing steam under heating and reduced pressure at a temperature of at least the boiling point of aniline or a large amount of inert gas such as nitrogen gas.

If the curable resin composition contains diphenylamine, the crosslinked structure may not be sufficiently formed, resulting in a significant drop in mechanical strength. In addition, when diphenylamine is contained in the aromatic amine resin represented by the formula (5), diphenylamine remains as it is even after maleimidation and remains in the cured product without contributing to the reaction, so that it is used for a long time. may bleed out and the thermal decomposition resistance may decrease. Therefore, the diphenylamine content is required to be preferably 1% by weight or less, more preferably 0.5% by weight or less, and even more preferably 0.2% by weight or less.

The maleimide resin represented by the formula (3) is obtained by reacting the aromatic amine resin represented by the formula (5) with maleic anhydride in the presence of a solvent and a catalyst. The method described in JP-A-61-229863 or the like may be employed. A water-insoluble solvent is used for the solvent used in the reaction because it is necessary to remove water generated during the reaction from the system. For example, aromatic solvents such as toluene and xylene; aliphatic solvents such as cyclohexane and n-hexane; ethers such as diethyl ether and diisopropyl ether; ester solvents such as ethyl acetate and butyl acetate; ketone-based solvents, etc., but are not limited to these, and two or more of them may be used in combination. An aprotic polar solvent can also be used in combination with the water-insoluble solvent. Examples thereof include dimethylsulfone, dimethylsulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-methylpyrrolidone and the like, and two or more of them may be used in combination. When an aprotic polar solvent is used, it is preferable to use one having a boiling point higher than that of the water-insoluble solvent used in combination. The catalyst is an acidic catalyst and is not particularly limited, and includes p-toluenesulfonic acid, hydroxy-p-toluenesulfonic acid, methanesulfonic acid, sulfuric acid, phosphoric acid and the like. For example, maleic acid is dissolved in toluene, an N-methylpyrrolidone solution of the compound represented by the formula (5) is added with stirring, p-toluenesulfonic acid is added, and the water generated under reflux conditions is removed. By performing the reaction while removing from the system, the maleimide compound represented by the formula (3) can be obtained.

The maleimide compound represented by the formula (3) preferably has a molecular weight distribution, and in the formula (3), the content of n = 1 by GPC analysis (RI) is preferably 98 area% or less. , more preferably 20 to 90 area %, still more preferably 30 to 80 area %, and particularly preferably 40 to 80 area %. When the content of n=1 is 98 area % or less, good heat resistance is achieved. Also, the crystallinity is lowered and the solvent solubility is improved. On the other hand, when the lower limit of n=1 is 20 area % or more, the viscosity of the resin solution is lowered and the impregnating property is improved. In addition, since the solvent can be removed at a low temperature when the solid is taken out, the self-polymerization hardly occurs and the handling becomes easy.

The method for producing the maleimide compound represented by the formula (4) is not particularly limited, and it may be produced by any known method for synthesizing maleimide compounds. When producing the maleimide resin represented by the formula (4), a compound represented by the following formula (6) is required as a precursor thereof. The method for producing the aromatic amine resin represented by the following formula (6) is not particularly limited. hydroxyisopropyl)benzene in the presence of an acidic catalyst at 180 to 250° C. to obtain the n=1 form of the formula (4) as a main component. Among n = 1 bodies, 1,3-bis(p-aminocumyl)benzene and 1,3-bis(o-aminocumyl)benzene, which have the same orientation with respect to two aniline molecules, have a symmetrical structure. It contains three isomers of a compound and an asymmetric structure compound with different orientations with respect to two aniline molecules such as 1-(o-aminocumyl)-3-(p-aminocumyl)benzene. Furthermore, subcomponents with n = 2 to 5 are also produced, and in JP-B-6-37465, these are purified by crystallization to obtain 1,3-bis(p-aminocumyl)benzene with a purity of 98%. ing. In JP-B-6-37465, 1,3-bis(p-aminocumyl)benzene is maleimidated to form N,N'-(1,3-phenylene-di-(2,2-propylidene)-di-p. -phenylene) bismaleimide to give a crystalline product.

(In formula (6), n is the number of repetitions, and the average value is 1<n<10.)

Acidic catalysts used in synthesizing the aromatic amine resin represented by the formula (6) include hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, zinc chloride, ferric chloride, aluminum chloride, p-toluenesulfonic acid, and methane. Examples include acidic catalysts such as sulfonic acid. In the present invention, protonic acids such as hydrochloric acid, p-toluenesulfonic acid and methanesulfonic acid are preferred. These may be used alone or in combination of two or more. The amount of catalyst used is preferably 1 to 12% by weight, more preferably 1 to 10% by weight, particularly preferably 1 to 7% by weight, based on 100% by weight of the aniline used, and is more than 12% by weight. Therefore, there are few compounds with the desired asymmetric structure, and compounds with a symmetric structure are preferentially produced. On the other hand, if it is less than 1%, not only does the progress of the reaction slow down, but the reaction may not be completed in some cases, which is not preferable.

The reaction may be carried out using an organic solvent such as toluene, xylene, or the like, if necessary, or may be carried out without a solvent. For example, after adding an acidic catalyst to a mixed solution of aniline and a solvent, if the catalyst contains water, it is preferable to azeotropically remove the water from the system. Thereafter, diisopropenylbenzene or di(α-hydroxyisopropyl)benzene is added, and then the temperature is raised while removing the solvent from the system to 140 to 190°C, preferably 160 to 190°C for 5 to 50 hours, preferably The reaction is carried out for 5-30 hours. If the reaction temperature is too high, the asymmetric structure is recombined after formation, and the target structure is preferentially formed, so that the desired solvent solubility and electrical properties cannot be exhibited. Since water is by-produced when di(α-hydroxyisopropyl)benzene is used, it is removed from the system while being azeotroped with the solvent when the temperature is raised. After completion of the reaction, neutralize the acidic catalyst with an alkaline aqueous solution, add a water-insoluble organic solvent to the oil layer, repeat washing with water until the wastewater becomes neutral, and remove the solvent and excess aniline derivative under heating and reduced pressure. . When activated clay or ion exchange resin is used, the reaction solution is filtered to remove the catalyst after completion of the reaction. Moreover, diphenylamine is produced as a by-product depending on the reaction temperature and the type of catalyst, and therefore it is preferable to remove it as necessary. The diphenylamine derivative is removed to 1% by weight or less, preferably 0.5% by weight or less, more preferably 0.2% by weight or less, under high temperature and high vacuum, or by using means such as steam distillation.

The maleimide resin represented by the formula (4) is obtained by combining the aromatic amine resin represented by the formula (6), maleic acid or maleic anhydride (hereinafter also referred to as "maleic anhydride") as a solvent, It can be obtained by an addition or dehydration condensation reaction in the presence of a catalyst.

The solvent used in the reaction is preferably a water-insoluble solvent because it is necessary to remove water generated during the reaction from the system. For example, aromatic solvents such as toluene and xylene; aliphatic solvents such as cyclohexane and n-hexane; ethers such as diethyl ether and diisopropyl ether; ester solvents such as ethyl acetate and butyl acetate; ketone-based solvents, etc., but are not limited to these, and two or more of them may be used in combination.

An aprotic polar solvent can also be used in combination with the water-insoluble solvent. Examples thereof include dimethylsulfone, dimethylsulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone and the like, and two or more of them may be used in combination. When an aprotic polar solvent is used, it is preferable to use one having a boiling point higher than that of the water-insoluble solvent used in combination.

In addition, the catalyst used in the reaction is an acidic catalyst and is not particularly limited, but examples thereof include p-toluenesulfonic acid, hydroxy-p-toluenesulfonic acid, methanesulfonic acid, sulfuric acid, phosphoric acid and the like. The amount of acid catalyst used is generally 0.1 to 10% by weight, preferably 1 to 5% by weight, relative to the aromatic amine resin.

For example, the aromatic amine resin represented by the formula (6) is dissolved in toluene and N-methyl-2-pyrrolidone, maleic anhydride is added to generate amic acid, and then p-toluenesulfone is dissolved. An acid is added and the reaction is carried out while removing the water generated from the system under reflux conditions.

Alternatively, maleic anhydride is dissolved in toluene, and under stirring, an N-methyl-2-pyrrolidone solution of the aromatic amine resin represented by the formula (6) is added to generate an amic acid, and then p- Toluenesulfonic acid is added, and the reaction is carried out while removing water generated from the system under reflux conditions.

Alternatively, maleic anhydride is dissolved in toluene, p-toluenesulfonic acid is added, and an N-methyl-2-pyrrolidone solution of the aromatic amine resin represented by the formula (6) is added dropwise under stirring and reflux conditions. Meanwhile, the water azeotroped during the reaction is removed from the system, and toluene is returned to the system during the reaction (the above is the first-stage reaction).

In any method, the amount of maleic anhydride is usually 1.0 to 3.0 equivalents, preferably 1.2 to 2.0 equivalents, relative to the amino group of the aromatic amine resin represented by formula (6). Use 0 eq.

In order to reduce the unclosed amic acid, water is added to the reaction solution after the maleimidation reaction listed above to separate the resin solution layer and the aqueous layer, and excess maleic acid, maleic anhydride, aprotic polar Solvents, catalysts, etc. are dissolved in the aqueous layer, so they are separated and removed, and the same operation is repeated to thoroughly remove excess maleic acid, maleic anhydride, aprotic polar solvents, and catalysts. . Excess maleic acid, maleic anhydride, an aprotic polar solvent, and a catalyst are added again to the maleimide resin solution of the organic layer from which the catalyst has been removed, and the dehydration ring-closing reaction of the remaining amic acid is performed again under heating and reflux conditions. A maleimide resin solution with a low acid value is obtained by the above (second stage reaction).

The time for the re-dehydration ring-closure reaction is usually 1 to 5 hours, preferably 1 to 3 hours, and if necessary, the above-mentioned aprotic polar solvent may be added. After completion of the reaction, the mixture is cooled and washed with water repeatedly until the washing water becomes neutral. Thereafter, after removing water by azeotropic dehydration under heating and reduced pressure, the solvent may be distilled off, another solvent may be added to adjust the resin solution to a desired concentration, or the solvent may be completely distilled. It may be removed and taken out as a solid resin.

The curable resin composition of the present invention contains a cyanate ester compound (B). Conventionally known cyanate ester compounds can be used as the cyanate ester compound (B). Specific examples of the cyanate ester compound (B) include polycondensates of phenols and various aldehydes, polymers of phenols and various diene compounds, polycondensates of phenols and ketones, and bisphenols and various aldehydes. cyanate ester compounds obtained by reacting polycondensates of phenols and aromatic dimethanols, phenols and aromatic dichloromethyls, phenols and aromatic bisalkoxymethyls, etc. with cyanogen halides. are not limited to these. These may be used alone or in combination of two or more.

Examples of the phenols include phenol, alkyl-substituted phenol, aromatic-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, and dihydroxynaphthalene.

Examples of the various aldehydes include formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, and cinnamaldehyde.

Examples of the various diene compounds include dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene and isoprene.

Examples of the ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone and benzophenone.

Examples of the aromatic dimethanols include benzenedimethanol and biphenyldimethanol; examples of the aromatic dichloromethyls include α,α'-dichloroxylene and bischloromethylbiphenyl; examples of the aromatic bisalkoxymethyls include bismethoxymethylbenzene. , bismethoxymethylbiphenyl, bisphenoxymethylbiphenyl and the like.

Maleimide compounds are not limited to those listed above. These may be used alone or in combination of two or more.

Examples of the cyanate ester compound (B) include compounds represented by the following formulas (7), (9) and (10).

(In formula (7), R ₅ to R ₈ may be the same or different and represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group. Y represents the following formulas (8-g) to (8 - Represents any one of the structures represented by l).)

(In formulas (8-g) to (8-l), * represents a bond to the benzene ring.)

(In formula (9), R ₉ to R ₁₂ may be the same or different and represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group. n is the number of repetitions, the average value of which is 1. <n<5.)

(In formula (10), Z represents any one of the structures represented by the following formulas (11-o) to (11-q). n is the number of repetitions, and the average value is 1 <n<5.)

(In formulas (11-o) to (11-q), * represents a bond to the naphthalene ring.)

In the curable resin composition of the present invention, the ratio of the maleimide compound (A) and the cyanate ester compound (B) is, with respect to the total weight of the maleimide compound (A) and the cyanate ester compound (B), the cyanate ester compound (B ) is preferably 10.0 to 80.0% by weight, more preferably 20.0 to 60.0% by weight, particularly preferably 20.0 to 50.0% by weight, and 30 0 to 40.0% by weight is most preferred. The functional group equivalent ratio is preferably 0.1 to 5.5 equivalents, more preferably 0.3 to 3.5 equivalents, of the cyanate ester compound (B) with respect to 1 equivalent of the maleimide compound (A). is more preferred, 0.5 to 2.0 equivalents is particularly preferred, and 0.8 to 1.2 equivalents is most preferred. If the amount of the cyanate ester compound (B) is less than the above range, the heat resistance will deteriorate. On the other hand, if the amount of the cyanate ester compound (B) exceeds the above range, the dielectric properties deteriorate. When the cyanate ester compound (B) is within the above range, a cured product excellent in both properties can be obtained without deterioration in heat resistance and dielectric properties.

Examples of the organometallic compound (C) of the present invention include organometallic salts such as tin octylate, zinc octylate, dibutyltin dimaleate, copper acetylacetonate, zinc naphthenate, cobalt naphthenate and tin oleate; zinc chloride; Examples include, but are not limited to, metal chlorides such as aluminum chloride and tin chloride. It may be used alone or in combination of two or more. Zinc octylate is most preferable from the viewpoint of solubility in solvents, and it is commercially available as Octope Zn (manufactured by Hope Pharmaceutical Co., Ltd.). If the amount of the organometallic compound (C) added to the curable resin composition of the present invention is too small, the reactivity will be insufficient and the heat resistance and dielectric properties of the cured product will deteriorate. On the other hand, if the amount added is too large, a large amount of the triazine compound, which is a trimer of the cyanate ester compound (B), will be produced. As a result, the maleimide compound (A) cannot react, and unreacted maleimide compound (A) remains in the system. As a result, dielectric properties deteriorate. The amount of the organometallic compound (C) added is preferably 0.01 to 0.50% by weight, more preferably 0.02 to 0.30% by weight, based on the total weight of the maleimide compound (A) and the cyanate ester compound (B). More preferably, 0.03 to 0.20% by weight is particularly preferable. Within the above range, an excellent cured product can be obtained in which the residual amount of the maleimide compound (A) in the system is suppressed while the reactivity is sufficient.

The phosphorus compound (D) of the present invention is not limited as long as it contains a phosphorus atom. Specific examples include phosphonium salts, phosphines, phosphine oxides, phosphates and phosphites. The phosphorus compound (D) is preferably a phosphonium salt or phosphine, more preferably a phosphonium salt, from the viewpoint of excellent reactivity and curability.

The phosphonium salt is preferably a compound composed of a phosphonium cation represented by the following formula (12) and a counter anion.

(In formula (12), R ₁₃ to R ₁₆ are the same or different and represent a hydrogen atom or a monovalent hydrocarbon group optionally having a substituent. In formula (9), R ₁₇ is Boron (B), bromine (Br), chlorine (Cl), hydroxyl group (OH), R ₂₂ —COO (R ₂₂ represents an optionally substituted monovalent hydrocarbon group) In the formula, R ₁₈ to R ₂₁ are the same or different and represent a hydrogen atom or a monovalent organic group optionally having a substituent. is preferably a hydrocarbon group and may have a substituent.)

Specific examples of the phosphonium salts represented by the formula (12) include tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, tri-t-butylphosphonium tetraphenylborate, and tetrabutylphosphonium tetraphenylborate. , tetrabutylphosphonium bromide, tetraphenylphosphonium bromide, methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide, tetrabutylphosphonium hydroxide, methoxymethyltriphenylphosphonium chloride, benzyltriphenylphosphonium chloride, Tetrabutylphosphonium acetate is mentioned.

The amount of the phosphorus compound (D) added in the curable resin composition of the present invention is preferably 0.1 to 5.0% by weight based on the total weight of the maleimide compound (A) and the cyanate ester compound (B). , more preferably 0.2 to 3.0% by weight, particularly preferably 0.3 to 2.0% by weight. If the content of the phosphorus compound (D) is less than 0.1%, the effect of the curing accelerator in the present invention cannot be sufficiently exhibited. On the other hand, when it is more than 5.0%, ionic compounds such as phosphonium salts, polar compounds such as phosphine oxides formed by oxidation of phosphines and phosphites during production of cured products, and phosphoric compounds such as phosphates. remains or forms in the cured resin composition, resulting in deterioration of dielectric properties. When the content of the phosphorus compound (D) is within the above range, it is possible to obtain an excellent cured product in which the effect of the curing accelerator is fully exhibited and deterioration of dielectric properties is suppressed.

The curable resin composition of the present invention needs to contain an organometallic compound (C) and a phosphorus compound (D) in addition to the maleimide compound (A) and cyanate ester compound (B). When the organometallic compound (C) is used with respect to the maleimide compound (A) and the cyanate ester compound (B), there is a large difference in the reaction rate, and as described above, the triazine compound in which the cyanate ester compound (B) is trimerized is quickly produced. Therefore, the maleimide compound (A) remains. Also here, when the amount of the organometallic compound (C) used is reduced in an attempt to suppress the reaction rate of the cyanate ester compound (A), the cyanate ester compound (A) cannot react completely and remains. there is a risk of Therefore, it is considered difficult to completely cure the organometallic compound (C) alone. By using the phosphorus compound (D) in combination as in the present invention, the electrons on the phosphorus react with the remaining maleimide compound (A) or cyanate ester compound (B) to increase the degree of curing. In addition, in the case of a counter ion having both an anion and a cation such as a phosphonium salt as a phosphorus compound, an anionic reaction and a cationic reaction occur at the same time, so the organometallic compound (C) and the phosphorus compound (D) are each independently The reaction proceeds more rapidly than when used in the above, and uncuring can be suppressed and the degree of curing can be increased.

Any known resin material can be used for the curable resin composition of the present invention in addition to the maleimide compound (A) and the cyanate ester compound (B). Specific examples include phenol resins, epoxy resins, amine resins, active alkene-containing resins, isocyanate resins, polyamide resins, polyimide resins, propenyl resins, methallyl resins, and active ester resins.

Phenolic resins, epoxy resins, amine resins, active alkene-containing resins, isocyanate resins, polyamide resins, polyimide resins, and active ester resins that can be used include, but are not limited to, the following examples. do not have.

Phenolic resin: phenols (phenol, alkyl-substituted phenol, aromatic-substituted phenol, hydroquinone, resorcinol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) and various aldehydes (formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, furfural, etc.), phenols and various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene, isoprene, etc.); Polycondensates, phenols and substituted biphenyls (4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl, etc.), or substituted Phenolic resins and bisphenols obtained by polycondensation with phenyls (1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene, 1,4-bis(hydroxymethyl)benzene, etc.) and various aldehyde polycondensates, polyphenylene ether.

Epoxy resins: glycidyl ether-based epoxy resins obtained by glycidylating the above phenolic resins, alcohols, etc., 4-vinyl-1-cyclohexene diepoxide, 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexane carboxylate, etc. Alicyclic epoxy resins, glycidylamine epoxy resins such as tetraglycidyldiaminodiphenylmethane (TGDDM) and triglycidyl-p-aminophenol, and glycidyl ester epoxy resins.

Amine resins: diaminodiphenylmethane, diaminodiphenylsulfone, isophoronediamine, naphthalenediamine, aniline novolak, orthoethylaniline novolak, aniline resin obtained by reaction of aniline with xylylene chloride, aniline described in Japanese Patent No. 6429862 and Substituted biphenyls (4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl, etc.) or substituted phenyls (1,4- bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis(hydroxymethyl)benzene, etc.).

Active alkene-containing resins: Polycondensates of the above phenol resins and active alkene-containing halogen compounds (chloromethylstyrene, allyl chloride, methallyl chloride, acrylic acid chloride, allyl chloride, etc.), active alkene-containing phenols (2- allylphenol, 2-propenylphenol, 4-allylphenol, 4-propenylphenol, eugenol, isoeugenol, etc.) and halogen compounds (4,4'-bis(methoxymethyl)-1,1'-biphenyl, 1,4 -Bis(chloromethyl)benzene, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, cyanuric chloride, etc.), epoxy resin or alcohol and substituted or non-substituted Polycondensates of substituted acrylates (acrylates, methacrylates, etc.), maleimide resins (4,4′-diphenylmethanebismaleimide, polyphenylmethanemaleimide, m-phenylenebismaleimide, 2,2′-bis[4-(4- Maleimidophenoxy)phenyl]propane, 3,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 4,4′-diphenyletherbismaleimide , 4,4′-diphenylsulfonebismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene).

Isocyanate resins: p-phenylene diisocyanate, m-phenylene diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, naphthalene diisocyanate, etc. Aromatic diisocyanates; isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hydrogenated xylene diisocyanate, norbornene diisocyanate, lysine diisocyanate and other aliphatic or alicyclic diisocyanates; one or more types of isocyanate monomers or an isocyanate trimerized from the above diisocyanate compound; a polyisocyanate obtained by a urethanization reaction between the above isocyanate compound and a polyol compound.

Polyamide resin: amino acids (6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, para-aminomethylbenzoic acid, etc.), lactams (ε-caprolactam, ω-undecanelactam, ω-laurolactam) and "diamine (ethylenediamine , trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine , heptadecanediamine, octadecanediamine, nonadecanediamine, eicosanediamine, 2-methyl-1,5-diaminopentane, 2-methyl-1,8-diaminooctane; cyclohexanediamine, bis-(4 -aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane and other alicyclic diamines; Aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid; terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, aromatic dicarboxylic acids such as 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; dialkyl esters of these dicarboxylic acids, and dichlorides). A polymer made from one or more of these as main raw materials.

Polyimide resin: the above diamine and tetracarboxylic dianhydride (4,4'-(hexafluoroisopropylidene) diphthalic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl- Cyclohexene-1,2 dicarboxylic anhydride, pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride , 2,2′,3,3′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-diphenylsulfonetetra Carboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, methylene-4,4'-diphthalic dianhydride, 1,1-ethylidene-4,4'-diphthalic acid dianhydride, 2,2'-propylidene-4,4'-diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'- Diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride anhydride, thio-4,4'-diphthalic dianhydride, sulfonyl-4,4'-diphthalic dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1, 3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,3-bis[2-(3,4-di Carboxyphenyl)-2-propyl]benzene dianhydride, 1,4-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, bis[3-(3,4-di Carboxyphenoxy)phenyl]methane dianhydride, bis[4-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, 1,3-bis( 3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalene Tetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic acid dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3 ,4-cyclobutanetetracarboxylic dianhydride), cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic acid dianhydride, 3,3′,4,4′-bicyclohexyltetracarboxylic dianhydride, carbonyl-4,4′-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4, 4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-ethylene-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,1-ethylidene- 4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2-propylidene-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4, 4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane -1,2-dicarboxylic acid) dianhydride, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, rel-[1S,5R,6R] -3-oxabicyclo[3,2,1]octane-2,4-dione-6-spiro-3′-(tetrahydrofuran-2′,5′-dione), 4-(2,5-dioxotetrahydrofuran- 3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, ethylene glycol-bis-(3,4-dicarboxylic anhydride phenyl) ether, 4,4′-biphenylbis (trimellitic monoester acid anhydride), 9,9′-bis(3,4-dicarboxyphenyl)fluorene dianhydride).

Active ester resin: A compound having one or more active ester groups in one molecule, such as an epoxy resin, can be used as a curing agent for a curable resin, if necessary. Active ester curing agents include compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. preferable. The active ester curing agent is preferably obtained by a condensation reaction of at least one of a carboxylic acid compound and a thiocarboxylic acid compound and at least one of a hydroxy compound and a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester curing agent obtained from a carboxylic acid compound and at least one of a phenol compound and a naphthol compound. agents are preferred.
Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.
Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m- cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucine, Benzenetriol, dicyclopentadiene-type diphenol compound, phenol novolak, and the like. Here, the term "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.
Preferred specific examples of the active ester curing agent include an active ester compound containing a dicyclopentadiene type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated phenol novolac, and a benzoylated phenol novolac. active ester compounds containing Among them, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadiene-type diphenol structure are more preferable. "Dicyclopentadiene-type diphenol structure" represents a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.
Commercially available active ester curing agents include, for example, active ester compounds containing a dicyclopentadiene type diphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", "HPC- 8000H-65TM", "EXB-8000L-65TM", "EXB-8150-65T" (manufactured by DIC); "EXB9416-70BK" (manufactured by DIC) as an active ester compound containing a naphthalene structure; acetylated phenol novolac "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester curing agent; "EXB-9050L-62M" manufactured by DIC Corporation as a phosphorus atom-containing active ester curing agent;

The curable resin composition of the present invention may optionally contain a curing accelerator other than the organometallic compound (C) and the phosphorus compound (D). Specific examples of curing accelerators that can be used include ketone peroxides such as methyl ethyl ketone peroxide and acetylacetone peroxide, diacyl peroxides such as benzoyl peroxide, dicumyl peroxide, 1,3-bis-(t-butyl dialkyl peroxides such as peroxyisopropyl)-benzene, peroxyketals such as t-butyl peroxybenzoate and 1,1-di-t-butylperoxycyclohexane, α-cumyl peroxyneodecanoate, t - butyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-amylperoxy-3,5,5-trimethylhexanoate, t-butylperoxy-3,5,5-trimethylhexanoate, t-amyl Alkyl peresters such as peroxybenzoate, di-2-ethylhexyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, t-butyl peroxyisopropyl carbonate, 1,6-bis(t- Peroxycarbonates such as butyl peroxycarbonyloxy)hexane, organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxyoctoate, lauroyl peroxide, and azobisisobutyronitrile , 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2,4-dimethylvaleronitrile) and other azo compounds, 2-methylimidazole, 2-ethylimidazole and 2-ethyl- imidazoles such as 4-methylimidazole, tertiary amines such as 2-(dimethylaminomethyl)phenol and 1,8-diaza-bicyclo(5,4,0)undecene-7, phosphines such as triphenylphosphine , tetrabutylammonium salt, triisopropylmethylammonium salt, trimethyldecanyl ammonium salt, cetyltrimethylammonium salt, hexadecyltrimethylammonium hydroxide and other quaternary ammonium salts.

A light stabilizer may be added to the curable resin composition of the present invention, if necessary. Hindered amine-based light stabilizers, particularly HALS, are suitable as the light stabilizer. HALS are not particularly limited, but representative ones include dibutylamine/1,3,5-triazine/N,N'-bis(2,2,6,6-tetramethyl-4- Polycondensation product of piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, dimethyl-1-(2-hydroxyethyl)-4-hydroxy succinate -2,2,6,6-tetramethylpiperidine polycondensate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl)imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl)imino}], bis(1,2,2, 6,6-pentamethyl-4-piperidyl)[{3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl}methyl]butylmalonate, bis(2,2,6,6-tetramethyl) -4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate, and the like. Only one type of HALS may be used, or two or more types may be used in combination.

The curable resin composition of the present invention may optionally contain a binder resin. Examples of binder resins include butyral resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenol resins, epoxy-NBR resins, polyamide resins, polyimide resins, and silicone resins. , but not limited to these. The blending amount of the binder resin is preferably within a range that does not impair the flame retardancy and heat resistance of the cured product, preferably 0.05 to 50 parts by mass, more preferably 0.05 to 50 parts by mass based on 100 parts by mass of the resin component. 0.05 to 20 parts by weight are used as needed.

The curable resin composition of the present invention may optionally contain fused silica, crystalline silica, porous silica, alumina, zircon, calcium silicate, calcium carbonate, quartz powder, silicon carbide, silicon nitride, boron nitride, zirconia, nitriding. Powders such as aluminum, graphite, forsterite, steatite, spinel, mullite, titania, talc, clay, iron oxide asbestos, glass powder, etc., or inorganic fillers in the form of spheres or pulverized powders thereof can be added. . In particular, when obtaining a curable resin composition for semiconductor encapsulation, the amount of the inorganic filler used is usually 80 to 92% by mass, preferably 83 to 90% by mass in the curable resin composition. be.

The curable resin composition of the present invention may optionally contain known additives. Specific examples of additives that can be used include polybutadiene and its modified products, modified acrylonitrile copolymers, polyphenylene ethers, polystyrene, polyethylene, polyimide, fluororesins, silicone gels, silicone oils, fillers such as silane coupling agents. Coloring agents such as surface treatment agents for materials, release agents, carbon black, phthalocyanine blue, and phthalocyanine green. The blending amount of these additives is preferably 1.000 parts by mass or less, more preferably 700 parts by mass or less per 100 parts by mass of the resin component.

The curable resin composition of the present invention is obtained by uniformly mixing the above-mentioned respective components in a predetermined ratio, usually precured at 130 to 180 ° C. for 30 to 500 seconds, and further cured at 150 to 200 ° C. After curing for 2 to 15 hours at , the curing reaction proceeds sufficiently to obtain the cured product of the present invention. It is also possible to uniformly disperse or dissolve the components of the curable resin composition in a solvent or the like, remove the solvent, and then cure the composition.

The curable resin composition of the present invention thus obtained has heat resistance, a low dielectric constant and a low dielectric loss tangent. Therefore, the curable resin composition of the present invention can be used in a wide range of fields requiring heat resistance, high adhesiveness, low dielectric constant and low dielectric loss tangent. Specifically, it is useful as an insulating material, laminate (printed wiring board, BGA substrate, build-up substrate, etc.), sealing material, resist, and all other materials for electrical and electronic parts. In addition to molding materials and composite materials, it can also be used in fields such as paint materials, adhesives, and 3D printing. Particularly in semiconductor encapsulation, solder reflow resistance is beneficial.

A semiconductor device has one encapsulated with the curable resin composition of the present invention. Examples of semiconductor devices include DIP (dual in-line package), QFP (quad flat package), BGA (ball grid array), CSP (chip size package), SOP (small outline package), TSOP (thin small outline package), and TQFP. (think quad flat package) and the like.

Although the method for preparing the curable resin composition of the present invention is not particularly limited, it is prepared by dispersing or dissolving each component in a solvent or the like as described above, uniformly mixing, and optionally distilling off the solvent. Alternatively, it may be prepolymerized. For example, maleimide compound (A) and cyanate ester compound (B) are prepolymerized by heating in the presence of organometallic compound (C) and phosphorus compound (D) in the presence or absence of a solvent. Similarly, in addition to the maleimide compound (A) and the cyanate ester compound (B), a curing agent such as an epoxy resin, an amine compound, a phenol resin, an acid anhydride compound, and other additives may be added to prepolymerize. Mixing or prepolymerization of each component is carried out by using, for example, an extruder, kneader, rolls, etc. in the absence of a solvent, and by using a reactor equipped with a stirrer in the presence of a solvent.

As a method for uniform mixing without using a solvent, etc., a uniform curable resin composition is obtained by kneading using a device such as a kneader, roll, planetary mixer, etc. at a temperature within the range of 50 to 100 ° C. do. After pulverizing the obtained curable resin composition, it is molded into a cylindrical tablet by a molding machine such as a tablet machine, or it is made into a granular powder or a powdery molding, or these compositions are used as a surface support. It is also possible to form a sheet having a thickness of 0.05 mm to 10 mm by melting above and forming a curable resin composition molded body. The obtained molded article becomes a non-sticky molded article at 0 to 20°C, and its fluidity and curability hardly deteriorate even when stored at -25 to 0°C for 1 week or longer.
The resulting molded product can be molded into a cured product using a transfer molding machine or a compression molding machine.

An organic solvent can be added to the curable resin composition of the present invention to form a varnish-like composition (hereinafter also simply referred to as varnish). If necessary, the curable resin composition of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. to form a varnish. , Polyester fiber, polyamide fiber, alumina fiber, paper, etc., is impregnated into a base material and heat-dried to obtain a prepreg, which is hot-press molded to obtain a cured product of the curable resin composition of the present invention. . In this case, the solvent is usually used in an amount of 10 to 70% by weight, preferably 15 to 70% by weight in the mixture of the curable resin composition of the present invention and the solvent. If the amount of solvent is less than this range, the viscosity of the varnish will increase and the workability will be deteriorated. Moreover, if it is a liquid composition, it is possible to obtain a curable resin-cured product containing carbon fibers by, for example, the RTM method.

The curable composition of the present invention can also be used as a modifier for film-type compositions. Specifically, it can be used to improve flexibility and the like in the B-stage. Such a film-type resin composition is obtained by applying the curable resin composition of the present invention as the curable resin composition varnish on a release film, removing the solvent under heating, and then performing B-stage. Thus, a sheet-like adhesive is obtained. This sheet-like adhesive can be used as an interlayer insulating layer in multilayer substrates and the like.

A prepreg can be obtained by heating and melting the curable resin composition of the present invention, reducing the viscosity, and impregnating reinforcing fibers such as glass fibers, carbon fibers, polyester fibers, polyamide fibers, and alumina fibers with the curable resin composition. Specific examples thereof include glass fibers such as E glass cloth, D glass cloth, S glass cloth, Q glass cloth, spherical glass cloth, NE glass cloth, and T glass cloth, inorganic fibers other than glass, and poly paraphenylene terephthalamide (Kevlar®, manufactured by DuPont), wholly aromatic polyamides, polyesters; and organic fibers such as polyparaphenylene benzoxazole, polyimides and carbon fibers, but are particularly limited to these. not. The shape of the substrate is not particularly limited, but examples thereof include woven fabric, nonwoven fabric, roving, chopped strand mat, and the like. Plain weave, Nanako weave, twill weave, and the like are known as weaving methods of woven fabric, and it is possible to appropriately select and use from these known methods depending on the intended use and performance. In addition, a woven fabric subjected to opening treatment or a glass woven fabric surface-treated with a silane coupling agent or the like is preferably used. Although the thickness of the base material is not particularly limited, it is preferably about 0.01 to 0.4 mm. A prepreg can also be obtained by impregnating reinforcing fibers with the varnish and heating and drying the varnish.

The laminate of the present embodiment includes one or more prepregs. The laminate is not particularly limited as long as it comprises one or more prepregs, and may have any other layers. As a method for producing a laminate, generally known methods can be appropriately applied, and there is no particular limitation. For example, when molding a metal foil-clad laminate, a multi-stage press machine, a multi-stage vacuum press machine, a continuous molding machine, an autoclave molding machine, etc. can be used, and the above prepregs are laminated and heat-pressed to form a laminate. Obtainable. At this time, the heating temperature is not particularly limited, but is preferably 65 to 300°C, more preferably 120 to 270°C. In addition, the pressure to be applied is not particularly limited, but if the pressure is too high, it will be difficult to adjust the solid content of the resin in the laminate and the quality will not be stable. 2.0 to 5.0 MPa is preferable, and 2.5 to 4.0 MPa is more preferable, because it deteriorates. The laminate of the present embodiment can be suitably used as a metal-foil-clad laminate described later by including a layer made of metal foil.
After cutting the prepreg into a desired shape and laminating it with copper foil or the like if necessary, the curable resin composition is heat-cured while applying pressure to the laminate by a press molding method, an autoclave molding method, a sheet winding molding method, or the like. Electrical and electronic laminates (printed wiring boards) and carbon fiber reinforcing materials can be obtained.

A cured product obtained by curing the curable resin composition of the present invention can be used as a sealing material for semiconductors. In general, maleimide compounds have excellent heat resistance and dielectric properties, but compared to widely used epoxy resins, etc., their melt viscosities are high and their resin flowability in spiral flow tests is low. It cannot be completely sealed, resulting in a defective product. On the other hand, one of the characteristics of the cyanate ester compound is its low melt viscosity. By using a maleimide compound and a cyanate ester compound together, the melt viscosity is lowered, the resin flowability is improved, and heat resistance and dielectric properties are improved. can be expressed. This cured product can be suitably used for applications that require heat resistance of 175° C. or higher, such as power semiconductors that operate at high temperatures for a long time, which are seen in recent years.

Since the cured product of the curable resin composition of the present invention exhibits excellent heat resistance and dielectric properties, it can be used as a semiconductor element sealing material, a liquid crystal display element sealing material, an organic EL element sealing material, a printed wiring board, It is suitably used for electric/electronic parts such as build-up laminates, and composite materials for lightweight and high-strength structural materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics.

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples. "Parts" and "%" in the text represent "parts by weight" and "% by weight", respectively.

Each measurement data was measured by the following method.
・Softening point: Measured by a method according to JIS K-7234 ・Melt viscosity: ICI melt viscosity (150°C) Measured by cone plate method, unit is Pa·s.

・GPC (gel permeation chromatography) analysis Manufacturer: Waters
Column: SHODEX GPC KF-601 (2 columns), KF-602, KF-602.5, KF-603
Flow rate: 0.5 ml/min.
Column temperature: 40°C
Solvent used: THF (tetrahydrofuran)
Detector: RI (differential refraction detector)

[Synthesis Example 1]
Synthesis of aromatic amine compound (A-1) 192 parts of aniline, 112 parts of toluene, 1,3-bis(2-hydroxy-2 -Propyl)benzene 100 parts was charged, and 21.5 parts of 35% hydrochloric acid was added dropwise over 10 minutes. The inside of the system was heated to 160° C., and the reaction was carried out at the same temperature for 17 hours while distilling off water and toluene. After cooling to 80° C., 124 parts of toluene was added, and 30 parts of a 30% sodium hydroxide aqueous solution was added dropwise over 10 minutes. After that, the mixture was stirred at the same temperature for 2 hours and allowed to stand for 30 minutes. The separated lower aqueous layer was removed, and the reaction solution was washed with water repeatedly until the washing solution became neutral. Then, excess aniline and toluene were distilled off from the oil layer under heating and reduced pressure using a rotary evaporator to obtain 158 parts of aromatic amine compound (A-1). The aromatic amine compound (A-1) had an amine equivalent of 186.1 g/eq and a softening point of 58.8°C. GPC analysis (RI) showed that n=1 was 62.5 area %. A GPC chart is shown in FIG.

[Synthesis Example 2]
Synthesis of maleimide compound (M-1) Into a flask equipped with a thermometer, a condenser, a Dean-Stark azeotropic distillation trap, and a stirrer, 73.5 parts of maleic anhydride, 126 parts of toluene, 1.86 parts of methanesulfonic acid, N. -Methyl-2-pyrrolidone (12.6 parts) was charged and heated to reflux. Next, a resin solution prepared by dissolving 93 parts of the aromatic amine compound (A-1) in 55.8 parts of toluene was added dropwise over 4 hours while maintaining the reflux state. During this time, condensed water and toluene azeotroping under reflux conditions were cooled and separated in a Dean-Stark azeotropic distillation trap, after which toluene as an organic layer was returned to the system and water was discharged to the outside of the system. After the dropping of the resin solution was completed, the reaction was carried out for 10 hours while maintaining the reflux state and performing dehydration.
After completion of the reaction, washing with water was repeated four times to remove methanesulfonic acid and excess maleic anhydride, and water was removed from the system by azeotropic distillation of toluene and water under heating and reduced pressure at 70°C or lower. Then, 0.93 part of methanesulfonic acid was added, and the reaction was carried out for 4 hours while heating to reflux. After completion of the reaction, after repeating washing with water four times until the washing water becomes neutral, water is removed from the system by azeotropic distillation of toluene and water under heating and reduced pressure at 70° C. or less, and then toluene is heated under reduced pressure. After the solvent was distilled off until the resin concentration reached about 70-80%, toluene was added to adjust the resin concentration to 60%. Thus, a maleimide solution (V-1) containing the maleimide compound (M-1) of the present invention was obtained. GPC analysis (RI) revealed that n=1 form of the obtained maleimide compound (M-1) was 57.4 area %. A GPC chart is shown in FIG. Also, the softening point was 115.5° C. and the viscosity was 6.0 Pa·s.

[Examples 1 and 2, Comparative Examples 1 and 2]
[DMA analysis]
Test piece preparation method: MIR-3000 (MIR-3000-70MT (manufactured by Nippon Kayaku Co., Ltd.) solvent was distilled off by heating and decompression) and bisphenol A type cyanate ester compound (manufactured by Mitsubishi Gas Chemical Co., Ltd.), etc. The proportions (parts by weight) shown in Table 1 were measured to obtain an equivalent weight, and acetone was added so that the resin solid content was 70%. Furthermore, TPP-K (manufactured by Hokko Chemical Co., Ltd.), TPP-MK (manufactured by Hokko Chemical Co., Ltd.), 18% Octope Zn (manufactured by Hope Pharmaceutical Co., Ltd.), and 2E4MZ (manufactured by Shikoku Kasei Co., Ltd.) are shown as curing accelerators. 1 and dissolved in the varnish. A curable resin composition was prepared by heating the varnish in which the curing accelerator was dissolved in a vacuum dryer at 60° C. for 30 minutes and at 80° C. for 1 hour. The resulting curable resin composition was sandwiched between copper foils and cured at 220° C. for 2 hours under vacuum with a pressure of 1 MPa. After removing the copper foil, the obtained cured product was cut into a size of 5 mm×40 mm to obtain a test piece.
Manufacturer: TA Instruments Device: DMAQ800
Measurement mode: Tensile Heating rate: 2°C/min.
Measurement temperature range: 25°C to 350°C
Measurement frequency: 10Hz
In order to confirm the reactivity and curability, Table 1 shows the values obtained by dividing the storage elastic modulus at 300°C by the storage elastic modulus at 250°C. Also, a DMA chart is shown in FIG.

List of curing accelerators Phosphorus compound: TPP-K (manufactured by Hokko Chemical Co., Ltd.)
・ Phosphorus compound: TPP-MK (manufactured by Hokko Chemical Co., Ltd.)
・ Organometallic compound: 18% octope Zn (manufactured by Hope Pharmaceutical Co., Ltd.)
・ Imidazole: 2E4MZ (manufactured by Shikoku Kasei Co., Ltd.)

In Examples 1 and 2, the value obtained by dividing the storage modulus at 300°C by the storage modulus at 250°C is 1 or less, while the value in Comparative Examples 1 and 2 is greater than 1. In each of the samples of Examples 1 and 2 and Comparative Examples 1 and 2, the glass region is between room temperature and around 150°C, and the rubber region is above 250°C. However, Comparative Examples 1 and 2 have an increased storage modulus in the rubber region. This phenomenon suggests that cross-linking proceeds at a temperature of 250° C. or higher. That is, in Comparative Examples 1 and 2, curing was insufficient under the curing conditions of curing for 2 hours at 220° C. under a vacuum pressure of 1 MPa. It can be said that

[Examples 3 to 6]
A maleimide compound and a bisphenol A cyanate ester compound (manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a maleimide compound and a cyanate ester compound are weighed in equal amounts at the ratios (parts by weight) shown in Table 2, and the resin solid content is 50 to 70%. After adding acetone so that it becomes , the varnish was produced by heating and mixing at 70° C. for 1 hour. Further, 18% Octope Zn (manufactured by Hope Pharmaceutical Co., Ltd.) and TPP-K (manufactured by Hokko Chemical Co., Ltd.) were weighed out at the ratios shown in Table 2 as curing accelerators and dissolved in the varnish. A curable resin composition was prepared by heating the varnish in which the curing accelerator was dissolved in a vacuum dryer at 60° C. for 30 minutes and at 80° C. for 1 hour. The resulting curable resin composition was sandwiched between copper foils and cured at 220° C. for 2 hours under vacuum with a pressure of 1 MPa. Table 2 shows the results.

[DMA analysis]
Test piece preparation method: A test piece was obtained by cutting the cured product obtained by the method described above into a size of 5 mm x 40 mm.
Manufacturer: TA Instruments Device: DMAQ800
Measurement mode: Tensile Heating rate: 2°C/min.
Measurement temperature range: 25°C to 350°C
Measurement frequency: 10Hz
The temperature at which tan δ becomes maximum was defined as Tg.

Dielectric constant test, dielectric loss tangent test Test piece preparation method: A test piece was obtained by cutting the cured product obtained by the method described above into a size of 2.5 mm x 50 mm. After drying the test piece in a dryer at 120° C. for 2 hours, the initial dielectric constant (Dk) and the initial dielectric loss tangent (Df) were measured. Furthermore, after the test piece was immersed in water for 24 hours, it was taken out and allowed to stand in an environment of 25°C and 30% for 24 hours, and then the measurement was performed again. After the test piece was left in an oven at 150° C. for 24 hours, the measurement was performed again. Using the obtained results, the rate of change after water absorption and after oxidation was calculated according to the following formula.
Df change rate after 24h water absorption [%] = {(Df after 24h water absorption - initial Df) / initial Df} x 100
Df change rate after 24h oxidation [%]={(Df after 24h oxidation−initial Df)/initial Df}×100
Manufacturer: AET Co., Ltd.
Equipment: 10 GHz cavity resonator

List of maleimide compounds M-1 (obtained in Synthesis Example 2 by distilling off the solvent by heating under reduced pressure)
・MIR-3000 (MIR-3000-70MT (manufactured by Nippon Kayaku Co., Ltd.) solvent is distilled off by heating under reduced pressure)
・ BMI-70 (manufactured by K-I Kasei Co., Ltd.)
・ BMI-2300 (manufactured by Daiwa Kasei Co., Ltd.)

It was confirmed that Examples 3 to 6 all exhibited excellent heat resistance, water absorption properties, and dielectric properties. Among them, it was confirmed that Examples 3 and 4 in particular exhibited excellent characteristics.

[Examples 4, 7 to 9]
MIR-3000 as a maleimide compound and a bisphenol A cyanate ester compound (manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a cyanate ester compound were weighed out at the ratios (parts by weight) shown in Table 3, and acetone was added so that the resin solid content was 70%. After adding, the varnish was produced by heat-mixing at 70 degreeC for 1 hour. Further, 18% Octope Zn (manufactured by Hope Pharmaceutical Co., Ltd.) and TPP-K (manufactured by Hokko Chemical Co., Ltd.) were weighed out at the ratios shown in Table 3 as curing accelerators and dissolved in the varnish. A curable resin composition was prepared by heating the varnish in which the curing accelerator was dissolved in a vacuum dryer at 60° C. for 30 minutes and at 80° C. for 1 hour. The resulting curable resin composition was sandwiched between copper foils and cured at 220° C. for 2 hours under vacuum with a pressure of 1 MPa. Table 3 shows the results. Table 3 shows the equivalent weight of the bisphenol A cyanate ester compound when MIR-3000 is taken as 1 equivalent weight.

It was confirmed that Examples 4 and 7 to 9 all exhibited good heat resistance and dielectric properties. It was also confirmed that increasing the amount of the cyanate ester compound improves the heat resistance, and decreasing the amount improves the dielectric properties.

Claims (5)

A curable resin composition containing a maleimide compound (A), a cyanate ester compound (B), an organometallic compound (C), and a phosphorus compound (D),
A curable resin composition in which the maleimide compound (A) is represented by the following formula (1).

(In formula (1), multiple X, R ₁ , and p exist independently, and X is any one of structures represented by the following formulas (2-b) to (2-f) 1. R ₁ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aromatic group having 1 to 20 carbon atoms which may have a substituent, and p represents a real number of 1 to 3. , n is the number of repetitions, and its average value is 1<n<10.)

(In formulas (2-a) to (2-f), * represents a bond to a benzene ring. Multiple R ₂ , m, q, and r exist independently, and R ₂ is a hydrogen atom. , an alkyl group having 1 to 20 carbon atoms, or an aromatic group having 1 to 20 carbon atoms which may have a substituent, m is a real number of 1 to 50, q is 1 to 4, r is a real number of 1 to 3 represents.) The curable resin composition according to claim 1, wherein the cyanate ester compound (B) is 0.3 to 3.5 equivalents relative to 1 equivalent of the maleimide compound (A). 3. The curable resin composition according to claim 1, wherein the organometallic compound (C) contains a zinc atom. A prepreg in which the curable resin composition according to any one of claims 1 to 3 is held by a sheet-like fiber base material. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 3 or the prepreg according to claim 4.

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