TWI716573B - Maleimide resin, curable resin composition and cured product thereof - Google Patents

Abstract

The present invention provides a maleimide resin with a relatively small amount of unclosed amide acid, and provides a curable resin composition using the maleic imide resin for thermal decomposition, flame retardancy, and low Hardened product with excellent moisture absorption and strength. The maleimide resin system is represented by the following formula (1), and has an acid value of 5 mgKOH/g or less.

(In the formula, X represents an aromatic hydrocarbon group with 6 to 18 carbons. A plurality of R ₁ each independently represents a hydrogen atom, an alkyl group with 1 to 10 carbons or an aromatic group. m represents an integer of 1 to 4, p represents an integer from 1 to 3, n represents a real number from 1 to 10).

Description

Maleimide resin, curable resin composition and cured product thereof

The present invention relates to a high-quality maleimide resin, a curable resin composition using the same, and a cured product thereof, and is preferably used in electrical equipment such as semiconductor sealing materials, printed wiring boards, build-up laminates, etc. ‧Electronic parts, or light-weight and high-strength materials such as carbon fiber reinforced plastic and glass fiber reinforced plastic.

In recent years, laminated boards for mounting electrical and electronic components have been required to have a wide range of characteristics and higher levels due to the expansion of their use fields. For example, it is mainstream to mount conventional semiconductor chips on metal lead frames, but in most cases, semiconductor chips with high processing capabilities such as CPUs are mounted on build-up boards made of polymer materials. With the development of high-speed components such as CPUs, clock frequencies have become higher, and signal propagation delay or transmission loss will become a problem. Therefore, low dielectric constant and low dielectric loss tangent are required for wiring boards. At the same time, as the speed of components increases, the heat generation of the chip will increase, so the heat resistance must be improved. In addition, in recent years, mobile electronic devices such as mobile phones have become popular, and precision electronic devices have begun to be used and carried in outdoor environments or close to the body. Therefore, resistance to the external environment (especially resistance to humidity and heat) is required. Furthermore, in the automotive field, there is rapid progress in electronics, and precision electronic equipment is placed near the engine, and higher levels of heat and humidity resistance are required. On the other hand, due to the use of automotive or mobile devices Therefore, safety such as flame retardancy has become more important. However, in recent years, due to the increasing awareness of environmental issues, the use of halogen-based flame retardants has been avoided. Therefore, the demand for imparting flame retardancy without using halogen has increased.

Conventionally, for example, a wiring board using BT resin, which is a resin combined with a bisphenol A cyanate compound and a bismaleimide compound, as in Patent Document 1, has excellent heat resistance, chemical resistance, and electrical properties. , And it is widely used as a high-performance wiring board, but it must be improved under the conditions that require higher performance as described above.

In addition, in recent years, the weight reduction of airplanes, automobiles, trains, and ships has progressed due to the need for energy conservation. Especially in the field of conveying devices, research is being conducted to replace conventional metal materials with lightweight and high-strength carbon fiber composite materials. For example, in the Boeing 787, weight reduction is achieved by increasing the ratio of composite materials, thereby greatly improving fuel efficiency. In the aviation field, there is also a trend to introduce carbon fiber composite materials into the components around the engine in order to further reduce the weight. Of course, a high level of heat resistance is required. In the automotive field, although part of it is equipped with composite transmission shafts, there is also a trend to make car bodies from composite materials for luxury cars. In the field of carbon fiber composite materials, the following composite materials are conventionally used. The composite material uses epoxy resin bisphenol A diglycidyl ether or tetraglycidyl diamino diphenyl methane, etc., and as a hardening agent. It is made of amino diphenyl methane, diamino diphenyl methane, etc., but in order to make lighter weight and higher heat resistance more advanced, the application of composite materials must be expanded. As a material for this purpose, Diethylenimine resin is used as one of the means to conduct research.

Among them, in most cases, it is the bismaleimide compound which is a maleimide compound available on the market, and because it is a crystal with a higher melting point, it must be used in the form of a solution. However, these have the disadvantages of being difficult to dissolve in general organic solvents, and only dissolving in high boiling point and hygroscopic solvents such as N,N-dimethylacetamide and N-methyl-2-pyrrolidone. In addition, the cured product of the bismaleimide compound has relatively good heat resistance, but has the disadvantages of being brittle and having a large amount of moisture absorption.

In response to this, as in Patent Document 2, Patent Document 3, and Patent Document 4, maleimide resins with molecular weight distribution, relatively low softening point, and excellent solvent solubility have also been developed. It has been reported that the cured product has Heat resistance, flexibility on one side, and low moisture absorption.

On the other hand, regarding the maleimide compound, as described in Patent Document 5, it is pointed out that if the maleimide contains more impurities, the pot life of the varnish becomes shorter and the cured product has heat resistance. Shortcomings such as reduced performance, reduced impact resistance, and larger dielectric loss tangent. In addition, Patent Document 6 pointed out that if an unclosed ring amide acid or the like is contained as an impurity, the heat resistance of the hardened product will decrease, and when it is used as an electrical insulating material, the problem of wiring corrosion will occur. As a method of reducing impurities, Patent Document 5 discloses the following method: by adding water to the bismaleimide solution to reduce the solubility of the solvent and causing it to precipitate, adding a basic compound to the suspension for treatment And filter, and wash the obtained filter cake repeatedly. In addition, Patent Document 6 discloses a method of adding a poor solvent such as an alcohol or aliphatic solvent to the bismaleimide solution to reduce the solubility of the solvent to precipitate it, or performing filter cake washing Thereby reducing impurities.

[Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Publication No. 54-30440

Patent Document 2: Japanese Patent Laid-Open No. 3-100016

Patent Document 3: Japanese Patent Publication No. 8-16151

Patent Document 4: Japanese Patent Application Publication No. 2009-001783

Patent Document 5: Japanese Patent Laid-Open No. 55-13234

Patent Document 6: Japanese Patent Laid-Open No. 1-211563

Patent Document 7: Japanese Patent Application Publication No. 2005-264154

On the other hand, in the case of the maleimide resin with excellent solvent solubility as described above, even if it tries to precipitate by adding a poor solvent or water, it does not become crystals or powder, but becomes larger. Therefore, it cannot be filtered, or the yield is poor, or there is a large amount of waste water. Therefore, it is impossible to use the conventional impurity reduction method, and it is difficult to obtain high-purity maleimide resin.

The object of the present invention is to provide a curable resin composition containing maleimide resin to improve the thermal decomposition, flame retardancy, low moisture absorption, and strength, while the amount of unclosed amide acid is small The maleimide resin.

The inventors of the present invention conducted diligent studies to solve the above-mentioned problems, and as a result, completed the present invention.

That is, the present invention relates to [1] a maleimide resin, which is represented by the following formula (1) and has an acid value of 5 mgKOH/g or less,

(In the formula, X represents an aromatic hydrocarbon group with 6 to 18 carbons; there are multiple R ₁ each independently representing a hydrogen atom, an alkyl group with 1 to 10 carbons or an aromatic group; m represents an integer of 1 to 4, p represents an integer from 1 to 3, and n represents a real number from 1 to 10); [2] The maleimide resin as described in [1] above is represented by the following formula (2),

(In the formula, there are a plurality of R ₁ each independently represents a hydrogen atom, an alkyl group with 1 to 10 carbon atoms or an aromatic group; m represents an integer of 1 to 4, p represents an integer of 1 to 3, and n represents 1 to The real number of 10); [3] The maleimide resin as described in [1] above, which is represented by the following formula (3),

(In the formula, there are a plurality of R ₁ each independently represents a hydrogen atom, an alkyl group with 1 to 10 carbon atoms or an aromatic group; m represents an integer of 1 to 4, p represents an integer of 1 to 3, and n represents 1 to The real number of 10); [4] The maleimide resin as described in any one of [1] to [3] above, wherein the aromatic amine resin is combined with maleic acid or maleic acid After the dianhydride reacts to produce amide acid, the dehydration reaction is carried out in the presence of a catalyst. After the excess maleic acid or maleic anhydride is removed by washing with water, it is dehydrated again in the presence of the catalyst Ring-closing reaction; [5] A curable resin composition containing the maleimide resin described in any one of [1] to [4] in the preceding paragraph; [6] A cured product that will be as described in the preceding paragraph [5] The curable resin composition described in the description is cured; [7] A method for producing a maleimide resin, the maleimide resin is represented by the following formula (1), and the production The method is to make the aromatic amine resin react with maleic acid or maleic anhydride to produce amic acid, then perform dehydration reaction in the presence of a catalyst, and wash the excess maleic acid by washing with water Or after the maleic anhydride is removed, the dehydration and ring-closing reaction is performed again in the presence of a catalyst

(In the formula, X represents an aromatic hydrocarbon group with 6 to 18 carbons; there are multiple R ₁ each independently representing a hydrogen atom, an alkyl group with 1 to 10 carbons or an aromatic group; m represents an integer of 1 to 4, p represents an integer from 1 to 3, n represents a real number from 1 to 10).

Maleic imide resin with less amount of unclosed amide acid of the present invention It can improve the thermal decomposition, flame retardancy, low hygroscopicity, and strength of the cured product using the curable resin composition.

Hereinafter, the present invention will be explained in detail. First, for the convenience of description, the method for producing the maleimide resin of the present invention will be described.

(Method for manufacturing aromatic amine resin)

The maleimide resin of the present invention can use the aromatic amine resin of the following formula (4) to the following formula (6) as a precursor.

(In the formula, X represents an aromatic hydrocarbon group with 6 to 18 carbons. A plurality of R ₁ each independently represents a hydrogen atom, an alkyl group with 1 to 10 carbons or an aromatic group. m represents an integer of 1 to 4, p represents an integer from 1 to 3, n represents a real number from 1 to 10).

(In the formula, there are multiple R ₁ each independently representing a hydrogen atom, an alkyl group with 1 to 10 carbon atoms or an aromatic group. m represents an integer of 1 to 4, p represents an integer of 1 to 3, and n represents 1 to The real number of 10).

(In the formula, there are multiple R ₁ each independently representing a hydrogen atom, an alkyl group with 1 to 10 carbon atoms or an aromatic group. m represents an integer of 1 to 4, p represents an integer of 1 to 3, and n represents 1 to The real number of 10).

The preparation method of the aromatic amine resin of the above formula (4) to formula (6) is not particularly limited. For example, Patent Document 3 describes the derivatization of aniline derivatives and dihalomethylaralkyl derivatives or aralkyl alcohols However, the present invention uses the same methods as these to react aniline derivatives with dihalomethyl aralkyl derivatives or aralkyl alcohol derivatives to obtain formulas (4)~ (6) The aromatic amine resin.

Examples of aniline derivatives used include aniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 2-ethylaniline, 3-ethylaniline, 4-ethylaniline, 2 ,3-dimethylaniline, 2,4-dimethylaniline, 2,5-dimethylaniline, 2,6-dimethylaniline, 3,4-dimethylaniline, 3,5-dimethylaniline Aniline, 2-propylaniline, 3-propylaniline, 4-propylaniline, 2-isopropylaniline, 3-isopropylaniline, 4-isopropylaniline, 2-ethyl-6-methyl Base aniline, 2-second butyl aniline, 2-tert butyl aniline, 4-butyl aniline, 4-second butyl aniline, 4-tert butyl aniline, 2,3-diethyl aniline, 2,4-Diethylaniline, 2,5-Diethylaniline, 2,6-Diethylaniline, 2-isopropyl-6-methylaniline, 4-aminobiphenyl, etc. These can be used individually or in combination of 2 or more types.

As the dihalomethyl aralkyl derivative or aralkyl alcohol derivative used, 1,4-bischloromethylbenzene, 1,3-bischloromethylbenzene, 1,2-bis Chloromethylbenzene, 1,4-bisbromomethylbenzene, 1,3-bisbromomethylbenzene, 1,2-bisbromomethylbenzene, 1,4-dimethoxymethylbenzene, 1,3 -Dimethoxymethylbenzene, 1,2-dimethoxymethylbenzene, 1,4-diethoxymethylbenzene, 1,3-diethoxymethylbenzene, 1,2-di Ethoxymethylbenzene, 1,4-dihydroxymethylbenzene, 1,3-dihydroxymethylbenzene, 1,2-dihydroxymethylbenzene, 2,6-dihydroxymethylnaphthalene, 1,5 -Dihydroxymethylnaphthalene, 2,6-dimethoxymethylnaphthalene, 1,5-dimethoxymethylnaphthalene, 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'-diisopropoxymethylbiphenyl, 4,4'-diphenyl Isobutoxymethyl biphenyl, 4,4'-dibutoxymethyl biphenyl, 4,4'-di-tertiary butoxymethyl biphenyl, 4,4'-dihydroxymethyl biphenyl Benzene etc. These can be used individually or in combination of 2 or more types.

The usage amount of the dihalogenated methyl aralkyl derivative or aralkyl alcohol derivative is 0.05 to 0.8 mol, preferably 0.1 to 0.6 mol relative to 1 mol of the aniline derivative used.

During the reaction, acidic catalysts 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 as needed. These can be used alone or in combination of two or more. The amount of catalyst used is 0.1 to 0.8 mol, preferably 0.5 to 0.7 mol, relative to 1 mol of the aniline used. If there is too much, the viscosity of the reaction solution will be too high and it will become difficult to stir. If it is too small, the reaction will slow down.

The reaction can be carried out using organic solvents such as toluene and xylene as needed, and can also be carried out without a solvent. For example, after adding an acidic catalyst to a mixed solution of an aniline derivative and a solvent, when the catalyst contains water, the water is removed from the system by azeotropic boiling. Then, add the dihalogenated methyl aralkyl derivative or aralkyl alcohol derivative at 40 to 100°C, preferably 50 to 80°C for 1 to 5 hours, preferably 2 to 4 hours, and then, The temperature is raised while removing the solvent from the system, and the reaction is carried out at 180-240°C, preferably 190-220°C, for 5-30 hours, preferably 5-20 hours. After the reaction, after neutralizing the acid catalyst with an alkaline aqueous solution, a non-water-soluble organic solvent is added to the oil layer, washing is repeated until the wastewater becomes neutral, and then the solvent and excess aniline derivatives are removed under heating and reduced pressure.

Depending on the type of aniline derivative, diphenylamine derivative is by-produced. Therefore, under high temperature, high vacuum, or steam distillation, 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.

The maleimide resin of the present invention is based on the presence of a solvent and a catalyst, the aromatic amine resin of formula (4) to formula (6) obtained by the above steps and maleic acid or Maleic anhydride (hereinafter, also referred to as "maleic anhydride") undergoes addition or dehydration condensation reaction Should be obtained.

Regarding the solvent used in the reaction, since the water generated in the reaction must be removed from the system, a non-water-soluble solvent is used. Examples include: 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 such as butyl ketone and cyclopentanone are not limited to these, and two or more types can be used in combination.

Moreover, in addition to the above-mentioned water-insoluble solvent, an aprotic polar solvent may be used in combination. Examples include: dimethyl sulfide, dimethyl sulfide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-methyl-2- Pyrolidone, etc., can also be used in combination of two or more kinds. In the case of using an aprotic polar solvent, it is preferable to use a solvent having a boiling point higher than that of the non-water-soluble solvent used in combination.

In addition, the catalyst used in the reaction is an acidic catalyst, and is not particularly limited, and 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 usually 0.1 to 10% by weight, preferably 1 to 5% by weight relative to the aromatic amine resin.

For example, the aromatic amine resins of formulas (4) to (6) are dissolved in toluene and N-methyl-2-pyrrolidone, maleic anhydride is added to them to generate amide acid, and then added For p-toluenesulfonic acid, the generated water is removed from the system and reacted under reflux conditions.

Alternatively, the maleic anhydride is dissolved in toluene, and the N-methyl-2-pyrrolidone solution of the aromatic amine resin of formula (4) to formula (6) is added under stirring to generate amide acid. Later, p-toluenesulfonic acid was added, and the generated water was removed from the system and reacted under reflux conditions.

Or, dissolve maleic anhydride in toluene, add p-toluenesulfonic acid, The N-methyl-2-pyrrolidone solution of the aromatic amine resin of the above formula (4)~the above formula (6) is added dropwise under stirring and refluxing, and the water from azeotrope is removed to the system on the way The toluene is returned to the system and the reaction proceeds. (The above is the first stage reaction)

In any method, maleic anhydride is usually 1 to 3 times equivalent, preferably 1.2 to 2.0 times equivalent relative to the amine group of the aromatic amine resin of the above formula (4) to the above formula (6) .

In order to reduce the unclosed ring amic acid, which is the object of the present invention, water was added to the reaction solution after the maleimidization reaction listed above, which separated into a resin solution layer and a water layer. Maleic acid or maleic anhydride, aprotic polar solvents, catalysts, etc. are dissolved on the side of the water layer, so they are separated and removed, and the same operation is repeated to completely remove excess maleic acid. Acid or maleic anhydride, aprotic polar solvent, catalyst. Add the catalyst again to the excess maleic acid or maleic anhydride, aprotic polar solvent, and the maleimide resin solution of the organic layer from which the catalyst has been removed, and perform heating and reflux again The dehydration and ring-closing reaction of the residual amide acid under the conditions, thereby obtaining a maleimide resin solution with a lower acid value. (Second stage reaction)

The time for the re-dehydration and ring-closure reaction is usually 1 to 5 hours, preferably 1 to 3 hours, and the aforementioned aprotic polar solvent may also be added as needed. After the reaction, it was cooled and washed repeatedly until the washing water became neutral. Afterwards, after the water is removed by azeotropic dehydration under heating and reduced pressure, the solvent can be distilled off, or other solvents can be added to adjust the resin solution to the required concentration, or the solvent can be completely distilled off to obtain a solid resin Take out the form.

Next, the maleimide resin of the present invention will be described.

The maleimide resin system of the present invention obtained by the above manufacturing method has an acid value of 5 mgKOH/g or less, and has the structure of the following formula (1).

(In the formula, X represents an aromatic hydrocarbon group with 6 to 18 carbons. A plurality of R ₁ each independently represents a hydrogen atom, an alkyl group with 1 to 10 carbons or an aromatic group. m represents an integer of 1 to 4, p represents an integer from 1 to 3, n represents a real number from 1 to 10).

In the above formula (1), the aromatic hydrocarbon group having 6 to 18 carbon atoms which is X includes a phenyl group, a biphenyl group, and a triphenyl group. Phenyl and biphenyl are preferred, and biphenyl is more preferred.

Specifically, it is preferably a maleimide resin having a structure represented by the following formula (2) or the following formula (3).

(In the formula, there are multiple R ₁ each independently representing a hydrogen atom, an alkyl group with 1 to 10 carbon atoms or an aromatic group. m represents an integer of 1 to 4, p represents an integer of 1 to 3, and n represents 1 to The real number of 10).

(In the formula, there are multiple R ₁ each independently representing a hydrogen atom, an alkyl group with 1 to 10 carbon atoms or an aromatic group. m represents an integer of 1 to 4, p represents an integer of 1 to 3, and n represents 1 to The real number of 10).

Examples of the alkyl group having 1 to 10 carbon atoms in R ₁ in the above formulas (1) to (3) include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, Tertiary butyl, second butyl, n-pentyl, isopentyl, pentyl, n-hexyl, cyclopentyl, cyclohexyl, octyl, 2-ethylhexyl, nonyl, decyl, etc.

基、嘧啶基、喹啉基、吲哚基及咔唑基等。 Examples of the aromatic group in R ₁ in the above formulas (1) to (3) include aromatic hydrocarbon groups such as phenyl, biphenyl, indenyl, naphthyl, anthracenyl, stilbene, and pyrenyl, Furyl, thienyl, thienothienyl, pyrrolyl, imidazolyl, pyridyl, pyridine

Group, pyrimidinyl, quinolinyl, indolyl and carbazolyl, etc.

5。n之值可根據順丁烯二醯亞胺樹脂之藉由凝膠滲透層析法(GPC)之測定所求出之數量平均分子量的值算出，但可認為近似性地與根據作為原料之上述式(4)所表示之芳香族胺樹脂之GPC的測定結果所算出之n的值大致相同。 Also, as the average value of n, it is preferable to represent the average value of 1<n

5. The value of n can be calculated from the value of the number average molecular weight of the maleimide resin obtained by the gel permeation chromatography (GPC) measurement, but it can be considered to be approximately the same as that of the raw material. The value of n calculated by the GPC measurement result of the aromatic amine resin represented by the formula (4) is almost the same.

The acid value of the maleimide resin of the present invention is 5 mgKOH/g or less, preferably 4 mgKOH/g, and more preferably 3 mgKOH/g or less. The acid value can be measured by a method based on JIS K-0070: 1992.

If unclosed ring amide acid is included as an impurity, when the acid value is more than 5mgKOH/g, the heat resistance of the hardened material may decrease, and when used as an electrical insulating material, wiring corrosion may occur. .

The maleimide resin of the present invention can use those having a melting point and a softening point. In particular, when it has a melting point, it is preferably 200°C or lower, and when it has a softening point, it is preferably 150°C or lower.

When the melting point or softening point is too high, the possibility of gelation becomes higher when mixed with epoxy resin, which is not good.

The melt viscosity of the maleimide resin of the present invention at 150°C is usually 0.05-100 Pa‧s, preferably 0.1-40 Pa‧s.

Next, the curable resin composition of the present invention will be explained.

The curable resin composition of the present invention may contain a compound capable of undergoing a crosslinking reaction with the maleimide resin of the present invention. As the compound, as long as it has an amine group, cyanic acid Ester group, phenolic hydroxyl group, alcoholic hydroxyl group, allyl group, methallyl group, acryloyl group, methacryloyl group, vinyl group, conjugated dienyl group, etc. can be combined with maleimide resin The compound of the functional group (or structure) that undergoes the crosslinking reaction is not particularly limited.

Since the amine compound and the maleimide compound undergo a crosslinking reaction, the aromatic amine resin represented by the above formula (4) to formula (6) can also be used. Since the maleimide resin can also undergo self-polymerization, it can also be used alone. In addition, an amine compound other than the aromatic amine resin described in the above formula (4) to formula (6) or a maleimide compound other than the maleimide resin of the present invention may be used in combination.

The content of the maleimide resin in the curable resin composition of the present invention is usually 10% by weight or more, preferably 15% by weight or more, and more preferably 20% by weight. In the case of the above range, among the physical properties of the cured product, the mechanical strength is higher, the peel strength is also higher, and the heat resistance tends to be higher.

、苯胺-福馬林樹脂等，但並不限定於該等。該等可單獨使用，亦可併用2種以上。 As the amine compound that can be blended into the curable resin composition of the present invention, conventionally known amine compounds can be used. Specific examples of amine compounds include: diethylenetriamine, triethylenetetramine, tetraethylenepentamine, metaxylylenediamine, trimethylhexamethylenediamine, 2-methyl Pentamethylene diamine, diethylaminopropylamine, isophorone diamine, 1,3-diaminomethylcyclohexane, bis(4-aminocyclohexyl)methane, bis( 4-amino-3-methylcyclohexyl)methane, norbornene diamine, 1,2-diaminocyclohexane, diaminodiphenylmethane, m-phenylenediamine, diaminodiphenyl Dicyandiamide, polyoxypropylene diamine, polyoxypropylene triamine, N-amino ethyl piper

, Aniline-formalin resin, but not limited to these. These can be used individually or in combination of 2 or more types.

As the maleimide compound that can be blended into the curable resin composition of the present invention, conventionally known maleimide compounds can be used. As maleic acid Specific examples of imine compounds include: 4,4'-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylenedimaleimide , 2,2'-bis[4-(4-maleimide phenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4 '-Diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 4,4'-diphenyl ether bismaleimide Amide, 4,4'-diphenyl bis-maleimide, 1,3-bis(3-maleimide phenoxy)benzene, 1,3-bis(4 -Maleimide (phenoxy)benzene, etc., but not limited to these. These can be used individually or in combination of 2 or more types. Regarding the blending amount of the maleimide compound, the maleimide resin of the present invention is preferably 5 times or less, more preferably 2 times or less in weight ratio.

As the cyanate compound that can be blended into the curable resin composition of the present invention, a conventionally known cyanate compound can be used. Specific examples of cyanate ester compounds include: condensation polymers of phenols and various aldehydes, polymers of phenols and various diene compounds, condensation polymers of phenols and ketones, and bisphenols and various aldehydes The cyanate ester compound obtained by reacting the condensation polymer and the like with cyanogen halide is not limited to these. These may be used alone, or two or more kinds may be used.

As said phenols, phenol, alkyl substituted phenol, aromatic substituted phenol, naphthol, alkyl substituted naphthol, dihydroxy benzene, alkyl substituted dihydroxy benzene, dihydroxy naphthalene, etc. are mentioned.

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

Examples of the above-mentioned various diene compounds include: dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinyl Biphenyl, diisopropenyl biphenyl, butadiene, isoprene, etc.

As said ketones, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc. are mentioned.

In addition, the cyanate ester compound described in the synthesis method in JP 2005-264154 A is particularly suitable as a cyanate ester compound because of its low hygroscopicity, flame retardancy, and excellent dielectric properties.

As a compound having an allyl group or a methallyl group that can be blended into the curable resin composition of the present invention, for example, as a (meth)allyl compound, 4,4'-bisphenol A can be cited Diallyl ether, 4,4'-bisphenol F diallyl ether, 4,4'-bisphenol F dimethylallyl ether, tri(meth)allyl isocyanurate, 2,2-di (4-Acetyloxy-3-(methyl)allylphenyl)propane, bis(4-acetoxy-3-(methyl)allylphenyl)methane, bis(4-ethane Acetyloxy-3-(methyl)allylphenyl) sulfide, 2,2-bis(4-benzyloxy-3-(methyl)allylphenyl)propane, bis(4- Benzoyloxy-3-(methyl)allylphenyl)methane, bis(4-benzyloxy-3-(methyl)allylphenyl)methane, 2,2-bis( 4-tolyloxy-3-(methyl)allylphenyl)propane, bis(4-tolyloxy-3-(methyl)allylphenyl)methane, bis(4-toluene) Oxy-3-(methyl)allylphenyl) sulfide, 2,2-bis(4-propionyloxy-3-(methyl)allylphenyl)propane, bis(4-propionyl) Oxy-3-(methyl)allylphenyl)methane, bis(4-propionyloxy-3-(methyl)allylphenyl)sulfonate, 2,2-bis(4-butyryl) Oxy-3-(methyl)allylphenyl)propane, 2,2-bis(4-isobutanoyloxy-3-(methyl)allylphenyl)propane-allyl chloride, Allyl alcohol, allyl ethyl ether, allyl-2-hydroxy ethyl ether, allyl glycidyl ether, methallyl glycidyl ether, diallyl phthalate, trimethylolpropanediene Propyl ether, neopentylerythritol triallyl ether, triallyl isocyanurate.

In the curable resin composition of the present invention, an epoxy resin can be further blended. Make It is an epoxy resin that can be blended, and any of conventionally known epoxy resins can be used. Specific examples of epoxy resins include: condensation polymers of phenols and various aldehydes, polymers of phenols and various diene compounds, condensation products of phenols and ketones, and condensation products of bisphenols and various aldehydes Glycidyl ether-based epoxy resin made by glycidylation of alcohols and alcohols; with 4-vinyl-1-cyclohexene diepoxide or 3,4-epoxycyclohexylmethyl-3,4 '-Epoxycyclohexane carboxylate, etc. represented by alicyclic epoxy resin; represented by tetraglycidyldiaminodiphenylmethane (TGDDM) or triglycidyl-p-aminophenol, etc. Glycidylamine epoxy resin; glycidyl ester epoxy resin, etc., but not limited to these. These may be used alone, or two or more kinds may be used.

In addition, the phenol aralkyl resin obtained by the condensation reaction of phenols with the above-mentioned dihalomethyl aralkyl derivative or aralkyl alcohol derivative is used as a raw material to react with epichlorohydrin. The epoxy resin obtained by the dehydrochlorination reaction is particularly suitable as an epoxy resin because of its low hygroscopicity, flame retardancy, and excellent dielectric properties.

When the epoxy resin is blended, the blending amount is not particularly limited, and is preferably in the range of 0.1 to 10 times, more preferably 0.2 to 4 times, of the maleimide resin by weight ratio. If the blending amount of the epoxy resin is 0.1 times or less of the maleimide resin, the cured product may become brittle, and if it is 10 times or more, the dielectric properties may decrease.

In the curable resin composition of the present invention, a phenol resin and a compound having an acid anhydride group can be further blended.

As the phenol resin that can be blended, any of conventionally known phenol resins can be used. Specific examples of phenol resins include bisphenols (bisphenol A, bisphenol F, bisphenol S, biphenol, bisphenol AD, etc.), phenols (phenol, alkyl substituted phenol, aromatic substituted phenol, Naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) and various aldehydes (formaldehyde, ethyl Aldehydes, alkyl aldehydes, benzaldehydes, alkyl-substituted benzaldehydes, hydroxybenzaldehydes, naphthaldehydes, glutaraldehydes, phthalaldehydes, crotonaldehydes, cinnamaldehydes, etc.)condensates, phenols and various diene compounds (two Cyclopentadiene, terpenes, vinylcyclohexene, norbornane diene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butylene Diene, isoprene, etc.) polymers, phenols and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.) condensation polymers, phenols Condensation polymer with aromatic dimethanols (benzenedimethanol, α,α,α',α'-benzenedimethanol, biphenyldimethanol, α,α,α',α'-biphenyldimethanol, etc.), Polycondensates of phenols and aromatic dichloromethyls (α,α'-dichloroxylene, dichloromethyl biphenyl, etc.), polycondensates of bisphenols and various aldehydes, and these modified products, But it is not limited to these. These may be used alone, or two or more kinds may be used.

In addition, the phenol aralkyl resin obtained by the condensation reaction of phenols with the above-mentioned dihalomethylaralkyl derivative or aralkyl alcohol derivative has low hygroscopicity, flame retardancy, and dielectric properties. Excellent, so it is particularly good as a phenol resin.

As the compound having an acid anhydride group that can be blended, any conventionally known compound can be used. Specific examples of the compound having an acid anhydride group include: 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2, 3,4-Cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, pyromellitic anhydride, 5-(2,5-dioxotetrahydrofuranyl)- 3-Methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetralin-1, 2-Dicarboxylic anhydride, etc.

The compound having an acid anhydride group can be used singly or in combination of two or more kinds. In addition, an acid anhydride group reacts with an amine, and as a result, it becomes an amide acid. If it is heated at 200°C to 300°C, it becomes an amide structure by a dehydration reaction, and it becomes a material with very excellent heat resistance.

In the curable resin composition of the present invention, a curing catalyst (curing accelerator) may be blended as necessary. Examples include: 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2- Imidazoles such as ethyl-4-methylimidazole; triethylamine, triethylenediamine, 2-(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0 ) Undecene-7, tris(dimethylaminomethyl)phenol, benzyldimethylamine and other amines; triphenylphosphine, tributylphosphine, trioctylphosphine and other phosphines; stannous octoate , Zinc octoate, dibutyltin dimaleate, zinc naphthenate, cobalt naphthenate, tin oleate and other organic metal salts; zinc chloride, aluminum chloride, tin chloride and other metal chlorides; two peroxides -Organic peroxides such as tertiary butyl and dicumyl peroxide; azo compounds such as azobisisobutyronitrile and azobisdimethylvaleronitrile; inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; trifluoride Lewis acids such as boron; salts such as sodium carbonate or lithium chloride, etc. The blending amount of the curing catalyst is in the range of 100 parts by weight in total with respect to the curable resin composition, preferably 10 parts by weight or less, more preferably 5 parts by weight or less.

An organic solvent can be added to the curable resin composition of the present invention to form a varnish-like composition (hereinafter, simply referred to as varnish). As the solvent used, for example, γ-butyrolactones; N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N -Dimethylimidazolidinone and other amine-based solvents; tetramethylene sulfonate and other sulfides; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether monoethyl Ether solvents such as acid esters and propylene glycol monobutyl ether; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; aromatic solvents such as toluene and xylene. The solvent is used in the obtained varnish with the solid content concentration excluding the solvent in the range of usually 10 to 80% by weight, preferably 20 to 70% by weight.

Furthermore, in the curable resin composition of the present invention, known The additives. Specific examples of additives that can be used include: epoxy resin hardeners, polybutadiene and its modified products, acrylonitrile copolymer modified products, polyphenylene ether, polystyrene, polyethylene, polyamide Amine, fluororesin, maleimide compound, cyanate ester compound, silicone gel, silicone oil, and silica, alumina, calcium carbonate, quartz powder, aluminum powder, graphite , Talc, clay, iron oxide, titanium oxide, aluminum nitride, asbestos, mica, glass powder and other inorganic filler materials, surface treatment agents for filler materials such as silane coupling agents, release agents, carbon black, phthalocyanine blue, Phthalocyanine and other colorants. The blending amount of these additives is preferably in the range of 1,000 parts by weight or less, more preferably 700 parts by weight or less with respect to 100 parts by weight of the curable resin composition.

The preparation method of the curable resin composition of the present invention is not particularly limited, and each component may be mixed uniformly, or prepolymerization may be performed. For example, prepolymerization is performed by heating the maleimide resin and the cyanate compound in the presence or absence of a catalyst, in the presence or absence of a solvent. Similarly, the maleimide resin of the present invention, epoxy resins, amine compounds, maleimide compounds, cyanate ester compounds, phenol resins, acid anhydride compounds, and other Additives are prepolymerized. Regarding the mixing or prepolymerization of the components, in the absence of a solvent, for example, an extruder, kneader, roll, etc. are used, and in the presence of a solvent, a reaction kettle with a stirring device is used.

The curable resin composition of the present invention is heated and melted to lower its viscosity and impregnated in reinforcing fibers such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, etc., thereby obtaining prepreg material.

Moreover, it is also possible to obtain a prepreg by impregnating the above-mentioned varnish in reinforcing fibers and heating and drying.

The above prepreg can be cut into the desired shape and laminated with copper foil if necessary, while applying pressure to the laminate by the pressure forming method, autoclave forming method, flat wire winding forming method, etc. The curable resin composition is heat-cured to obtain an electrical and electronic laminate (printed wiring board) or carbon fiber reinforced material.

[Example]

Hereinafter, the present invention will be specifically explained with examples and comparative examples. Furthermore, in this article, "parts" and "%" mean "parts by mass" and "% by mass" respectively. The softening point and melt viscosity are measured by the following methods.

‧Softening point: measured by the method according to JIS K-7234

‧Melting viscosity: the viscosity at 150℃ using the cone-plate method

‧Acid value: Measured by the method according to JIS K-0070: 1992

Synthesis example 1

Add 372 parts of aniline and 200 parts of toluene to a flask equipped with a thermometer, condenser, Dean-Stark azeotropic distillation separator, and agitator, while keeping 88 parts of 1,4-dichloromethylbenzene at 60~ The addition was carried out at 70°C for 1 hour, and the reaction was carried out at the same temperature for 2 hours. Then, while keeping 104 parts of 35% hydrochloric acid at 60 to 70°C, drip it over 1 hour. After the dripping, the temperature was raised while distilling to remove water and toluene, and the system was set to 205~210°C, and reacted at this temperature for 10 hours. After cooling, slowly add 277 parts of 30% sodium hydroxide aqueous solution in such a way that the system will not reflux violently, and return the toluene distilled off when the temperature rises to the system at a temperature below 80°C and place it still 70℃~80℃. Remove the separated lower water layer, and repeatedly wash the reaction solution with water until the cleaning solution becomes neutral. Then, by using a rotary evaporator, the excess aniline and toluene were distilled from the oil layer under heating and reduced pressure (200°C, 0.6KPa), thereby obtaining 138 parts of aromatic amine resin (a1) were obtained. The diphenylamine in the aromatic amine resin (a1) is 2.0%.

Regarding the obtained resin, the rotary evaporator was used again, and water was added drop by drop under heating and reduced pressure (200°C, 4KPa) instead of blowing in steam. As a result, 131 parts of aromatic amine resin (A1) were obtained. The obtained aromatic amine resin (A1) is a highly viscous liquid at room temperature, the amine equivalent is 150 g/eq, and the diphenylamine is 0.1% or less.

Synthesis Example 2

Add 372 parts of aniline and 200 parts of toluene to a flask equipped with a thermometer, condenser, Dean-Stark azeotropic distillation separator, and agitator, and 125 parts of 4,4'-bis(chloromethyl)biphenyl Add it for 1 hour while keeping the temperature at 60~70°C, and react for 2 hours at the same temperature. Then, while keeping 104 parts of 35% hydrochloric acid at 60 to 70°C, drip it over 1 hour. After the dripping, the temperature was raised while distilling to remove water and toluene, and the system was set to 205~210°C, and reacted at this temperature for 10 hours. After that, while cooling, 277 parts of 30% sodium hydroxide aqueous solution was slowly added dropwise so that the system would not reflux violently, and the toluene distilled off when the temperature was raised was returned to the system at a temperature below 80°C, and left to stand. At 70℃~80℃. Remove the separated lower water layer, and repeatedly wash the reaction solution with water until the cleaning solution becomes neutral. Then, using a rotary evaporator, excess aniline and toluene were distilled off from the oil layer under heating and reduced pressure (200° C., 0.6 KPa), thereby obtaining 173 parts of aromatic amine resin (a2). The diphenylamine in the aromatic amine resin (a2) is 2.0%.

Regarding the obtained resin, the rotary evaporator was used again, and water was added drop by drop under heating and reduced pressure (200°C, 4KPa) instead of blowing in steam. As a result, 166 parts of aromatic amine resin (A2) were obtained. The obtained aromatic amine resin (A2) had a softening point of 56°C, a melt viscosity of 0.035 Pa‧s, an amine equivalent of 195 g/eq, and a diphenylamine of 0.1% or less.

Example 1

Add 147 parts of maleic anhydride, 200 parts of toluene, and 4 parts of methanesulfonic acid to a flask equipped with a thermometer, a condenser, a Dean-Stark azeotropic distillation separator, and a stirrer, and set it to a heating reflux state. Next, a resin solution obtained by dissolving 150 parts of aromatic amine resin (A1) in 95 parts of N-methyl-2-pyrrolidone and 95 parts of toluene was dropped over 3 hours while maintaining the reflux state. In the Dean-Stark azeotropic distillation separator, the condensed water and toluene that have been azeotropically boiled under reflux conditions during this period are cooled and separated, and the toluene as the organic layer is returned to the system, and The water is discharged out of the system. After the dripping of the resin solution is completed, the reflux state is maintained, and the reaction is carried out for 2 hours while performing the dehydration operation.

After the completion of the reaction, repeated washing with water was performed 4 times to remove methanesulfonic acid and excess maleic anhydride, and water was removed from the system by the azeotrope of toluene and water under heating and reduced pressure below 70°C. Then, 2 parts of methanesulfonic acid was added, and the reaction was performed for 2 hours under heating under reflux. After the reaction is over, wash with water repeatedly 4 times until the washing water becomes neutral, then remove the water from the system by the azeotrope of toluene and water under heating and reduced pressure below 70°C, and then completely distill off the toluene. This obtains the maleimide resin (M1) of the present invention. The obtained maleimide resin has a softening point of 94°C, a melt viscosity of 4 Pa.s, and an acid value of 1.9 mgKOH/g.

Example 2

Add 147 parts of maleic anhydride, 200 parts of toluene, and 4 parts of methanesulfonic acid to a flask equipped with a thermometer, a condenser, a Dean-Stark azeotropic distillation separator, and a stirrer, and set it to a heating reflux state. Next, while maintaining the reflux state, a resin solution prepared by dissolving 195 parts of aromatic amine resin (A2) in 95 parts of N-methyl-2-pyrrolidone and 95 parts of toluene was added dropwise over 3 hours. In the Dean-Stark azeotropic distillation separator, it will azeotrope under reflux conditions during this period After the condensed water and toluene are cooled and separated, the toluene as the organic layer is returned to the system, and the water is discharged out of the system. After the dripping of the resin solution is completed, the reflux state is maintained, and the reaction is carried out for 2 hours while performing the dehydration operation.

After the completion of the reaction, repeated washing with water was performed 4 times to remove methanesulfonic acid and excess maleic anhydride, and water was removed from the system by the azeotrope of toluene and water under heating and reduced pressure below 70°C. Then, 2 parts of methanesulfonic acid was added, and the reaction was performed for 2 hours under heating under reflux. After the reaction is over, wash with water repeatedly 4 times until the washing water becomes neutral, then remove the water from the system by the azeotrope of toluene and water under heating and reduced pressure below 70°C, and then completely distill off the toluene. This obtains the maleimide resin (M2) of the present invention. The obtained maleimide resin has a softening point of 109°C, a melt viscosity of 5Pa‧s, and an acid value of 1.6mgKOH/g.

Comparative example 1

Add 400 parts of toluene and 100 parts of N-methyl-2-pyrrolidone to a flask equipped with thermometer, condenser, Dean-Stark azeotropic distillation separator, and stirrer, and add aromatic amine resin (A1) 150 parts and dissolve. Then, while keeping the temperature at 50-60°C, 147 parts of maleic anhydride was added in batches over 1 hour. After that, it was reacted at 80°C for 2 hours, 2 parts of methanesulfonic acid was added, and the reaction was performed at 110 to 120°C for 14 hours. In the Dean-Stark azeotropic distillation separator, the condensed water and toluene that were azeotropically boiled under reflux conditions during this period were cooled and separated, and the toluene as the organic layer was returned to the system, and the water Exhaust to the outside of the system. After the completion of the reaction, after repeated washing with water 7 times, toluene was completely distilled off under heating and reduced pressure to obtain a maleimide resin (C1) for comparison. The obtained maleimide resin had a softening point of 95°C, a melt viscosity of 5 Pa.s, and an acid value of 8.1 mgKOH/g.

Comparative example 2

Add 400 parts of toluene and 100 parts of N-methyl-2-pyrrolidone to a flask equipped with thermometer, condenser, Dean-Stark azeotropic distillation separator, and stirrer, and add aromatic amine resin (A1) 195 parts and dissolved. Then, while keeping the temperature at 50-60°C, 147 parts of maleic anhydride was added in batches over 1 hour. After that, it was reacted at 80°C for 2 hours, 2 parts of methanesulfonic acid was added, and the reaction was performed at 110 to 120°C for 14 hours. In the Dean-Stark azeotropic distillation separator, the condensed water and toluene that were azeotropically boiled under reflux conditions during this period were cooled and separated, and the toluene as the organic layer was returned to the system, and the water Exhaust to the outside of the system. After completion of the reaction, after repeated washing with water 7 times, toluene was completely distilled off under heating and reduced pressure to obtain a maleimide resin (C2) for comparison. The obtained maleimide resin has a softening point of 119°C, a melt viscosity of 6Pa‧s, and an acid value of 6mgKOH/g.

Examples 3~4, Comparative Examples 3~4

The maleimide resins (M1), (M2) and (C1), (C2) obtained in Examples 1 and 2, Comparative Examples 1 and 2 were blended in proportions (parts by weight) in Table 1 After mixing various epoxy resins, hardeners, and hardening accelerators, they are kneaded with a mixing roller and plated, and then a resin molded body is prepared by transfer molding and cured at 200°C for 2 hours. For the following items, the physical properties of the cured product obtained in the above manner were measured, and the measured results are shown in Table 1.

‧Glass transition temperature: measured by a dynamic viscoelastic testing machine, the temperature when ten δ is the maximum value.

‧Td5 (5% thermal weight loss temperature): Use the hardened product obtained by pulverization to become a powder through 100 mesh and stay in the 200 mesh sample. The thermal decomposition temperature is measured by TG-DTA. The measurement was performed under the conditions of a sample volume of 10 mg, a heating rate of 10°C/min, and an air volume of 200 ml/hr. The temperature was 5% weight loss.

‧Flame resistance test: Use a sample with a sample size of 12.5mm in width, 150mm in length, and 0.8mm in thickness to measure the total residual flame time.

‧Bending strength: Measured according to JIS K-6911.

‧Moisture absorption rate: the weight increase rate after 24 hours at 85℃/85% and 121℃/100%. The test piece is a disc with a diameter of 50mm × a thickness of 4mm.

‧Curing shrinkage: Measured according to JIS K-6911.

According to Table 1, it can be confirmed that the cured product of the maleimide resin of the present invention is superior in heat resistance, strength, and moisture absorption compared to the cured product of the maleimide resin with a higher acid value Less sex. Since Td5 is high, the thermal decomposition temperature is high, so it is excellent in flame retardancy. In addition, since the shrinkage rate is small, when it is used in laminates or carbon fiber composite materials, the dimensional changes caused by molding are less, and it becomes easier to produce molded products of designed dimensions.

The present invention has been described in detail with reference to specific aspects, but the industry should understand that various changes and modifications can be made without departing from the spirit and scope of the present invention.

In addition, this application is based on a Japanese patent application (Japanese Patent Application 2016-065226) filed on March 29, 2016, and the entire content is incorporated by reference. Also, as quoted in this article All reference systems used are incorporated as a whole.

Claims (5)

A method for manufacturing a maleimide resin, the maleimide resin is represented by the following formula (1), and the manufacturing method is based on combining an aromatic amine resin with maleic acid or cis After the butenedioic anhydride reacts to produce amic acid, the dehydration reaction is carried out in the presence of a catalyst, and the excess maleic acid or maleic anhydride is removed by washing with water, and then again in the presence of the catalyst Carry out dehydration and ring closure reaction,

(In the formula, X represents an aromatic hydrocarbon group with 6 to 18 carbons; there are multiple R ₁ each independently representing a hydrogen atom, an alkyl group with 1 to 10 carbons or an aromatic group; m represents an integer of 1 to 4, p represents an integer from 1 to 3, n represents a real number from 1 to 10). For example, the method for producing maleimide resin in the first item of the scope of patent application, wherein the maleimide resin represented by the above formula (1) is the maleimide resin represented by the following formula (2) Endiimide resin,

(In the formula, there are a plurality of R ₁ each independently represents a hydrogen atom, an alkyl group with 1 to 10 carbon atoms or an aromatic group; m represents an integer of 1 to 4, p represents an integer of 1 to 3, and n represents 1 to The real number of 10). For example, the method for producing maleimide resin in the first item of the scope of patent application, wherein the maleimide resin represented by the above formula (1) is a cis-based resin represented by the following formula (3) Butylene diimide resin,

(In the formula, there are a plurality of R ₁ each independently represents a hydrogen atom, an alkyl group with 1 to 10 carbon atoms or an aromatic group; m represents an integer of 1 to 4, p represents an integer of 1 to 3, and n represents 1 to The real number of 10). A method for manufacturing a curable resin composition uses the method for manufacturing a maleimide resin in any one of items 1 to 3 in the scope of patent application. A method for manufacturing hardened objects, which includes The step of curing the curable resin composition obtained by the method of manufacturing the curable resin composition of the fourth item of the scope of patent application.