Bismaleimide and method for producing the same

Abstract

To provide bismaleimide with sufficiently reduced formation of by-products.SOLUTION: The present invention provides a bismaleimide having maleimidized amino groups of an aliphatic diamine, wherein, when a quantitative comparison is performed in 1H-NMR using the integral value (A) of the peak corresponding to the proton of the methylene group directly bound to the nitrogen atom of the maleimide group and the integral value (B) of the peak corresponding to the vinyl proton of the maleimide group, the ratio B / A exceeds 0.80. The bismaleimide is suitably applicable as an ingredient in a sealing composition or an adhesive composition employed in electronic part fabrication using semiconductors or the like.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to bismaleimide and a method for producing the same.

Background Art

[0002] Electronic components used in electronic devices such as mobile phones, smartphones, and notebook computers are advancing in high-density integration and high-density mounting. Resin materials such as adhesives and encapsulants used in these electronic components require heat-resistant materials with low water absorption and excellent reliability. As components of compositions used in these adhesives, encapsulants, etc., a method of using bismaleimide in which the amino group of an aliphatic diamine is maleimidized is known. For example, Patent Document 1 discloses a method of using maleimide as a component of an adhesive composition for mounting LED elements. Patent Document 2 discloses a method of using bismaleimide as a component of an anisotropic conductive adhesive composition for a printed wiring board.

[0003] Aliphatic bismaleimide can be obtained by known methods disclosed in Patent Documents 3 to 5, etc. That is, for example, it can be produced by reacting a diamine and maleic anhydride in a solvent under an acid catalyst, imidizing, and purifying. These bismaleimides are also commercially available from Designer Molecules Inc. (sometimes abbreviated as DMI) under trade names such as BMI-689, BMI-1500, BMI-1700, and BMI-3000. Since these aliphatic bismaleimides contain trace amounts of acid components such as maleamic acid, fumaric acid, and Michael adducts (compounds formed by the Michael addition reaction of an amine with MAA and further reaction with maleic anhydride), there has been a problem that when used in electronic components, it has an adverse effect on electrical characteristics.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] The present invention solves the above problems, and an object thereof is to provide a bismaleimide in which the generation of by-products is sufficiently reduced. [Means for Solving the Problems]

[0006] As a result of intensive studies, the present inventors have found that the above problems can be solved by obtaining a bismaleimide by using two types of specific acid catalysts in combination, and have completed the present invention.

[0007] The present invention has the following gist. (1) A bismaleimide in which the amino groups of an aliphatic diamine are maleimidized, and when a quantitative comparison is made using the integral value (A) of the peak corresponding to the proton of the methylene group directly bonded to the nitrogen atom of the maleimide group and the integral value (B) of the peak corresponding to the vinyl proton of the maleimide group in 1H-NMR, a bismaleimide in which B / A is more than 0.80. 1 (2) A method for producing the bismaleimide according to claim 1, characterized in that an acid having a pKa of less than 1 and an acid having a pKa of 1 or more are used as catalysts in an amount of 115 mol% or more based on the mole of the aliphatic diamine. (2) A method for producing the bismaleimide according to claim 1, characterized in that an acid having a pKa of less than 1 and an acid having a pKa of 1 or more are used as catalysts in an amount of 115 mol% or more based on the mole of the aliphatic diamine. [Effects of the Invention]

[0008] The bismaleimide of the present invention has sufficiently suppressed generation of by-products. This is industrially advantageous when compounded with other agents. Therefore, it can be suitably used as a component of a sealing material composition, an adhesive composition, etc., which are used in the manufacture of electronic components using semiconductors and the like.

Brief Description of Drawings

[0009]

Figure 1

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in detail. The bismaleimide of the present invention has an NMR integral value ratio (B / A) in its 1 1H-NMR exceeding 0.80, and more preferably 0.82 or more. Further, B / A is more preferably 0.85 or more, and even more preferably 0.87 or more. Here, A is the integral value of the peak corresponding to the proton of the methylene group directly bonded to the nitrogen atom of the maleimide group, and B is the integral value of the peak corresponding to the vinyl proton of the maleimide group. The higher this integral value ratio, the higher the maleimide group content in the bismaleimide, that is, it means that the generation of Michael adducts and vinyl polymers, which are by-products, is suppressed when an aliphatic diamine reacts with maleic acid.

[0011] Here, the NMR measurement conditions are as follows. (See Figure 1) < 1 1H-NMR Measurement Conditions Apparatus: Nuclear magnetic resonance apparatus (manufactured by JEOL Ltd.: model number ECA500) Frequency: 500.16 MHz Reference substance: Tetramethylsilane Solvent: Deuterochloroform Measurement temperature: 25 °C Under the above measurement conditions, the chemical shift corresponding to the proton of the methylene group directly bonded to the nitrogen atom of the maleimide group of bismaleimide is about 3.5 ppm (peak 1 in Figure 1). Also, the chemical shift corresponding to the vinyl proton of the maleimide group of bismaleimide is about 6.7 ppm (peak 2 in Figure 1). Therefore, by reading the integral values of these peaks from the NMR chart, the NMR integral value ratio can be calculated.

[0012] The acid value of bismaleimide is a parameter that quantitatively represents the amount of acid component remaining as a by-product in bismaleimide, and a value measured by a neutralization titration method based on JIS K0070 (1992) can be used. The acid value of the bismaleimide of the present invention is not particularly limited, but is preferably 15 mg-KOH / g or less, more preferably 10 mg-KOH / g or less, and even more preferably 5 mg-KOH / g or less. The acid value of bismaleimide can be further reduced by the method described later, preferably 2 mg-OH / g or less, more preferably 1.7 mg-KOH / g or less, even more preferably 1 mg-KOH / g or less, and particularly preferably 0.5 mg-KOH / g or less.

[0013] The bismaleimide of the present invention has a chemical structure in which an aliphatic diamine and a maleic acid component are dehydrated and condensed. As the aliphatic diamine, it may be either saturated or unsaturated aliphatic, but preferably it is saturated aliphatic. The aliphatic diamine is not particularly limited, but for example, those having 6 to 50 carbon atoms can be used. Specific examples of the aliphatic diamine include hexamethylenediamine (6 carbon atoms), octamethylenediamine (8 carbon atoms), trimethylhexamethylenediamine (9 carbon atoms), decanediamine (10 carbon atoms), 1,4-bis(3-aminopropyl)piperazine (10 carbon atoms), dodecanediamine (12 carbon atoms), octadecanediamine (18 carbon atoms), nonadecanediamine (19 carbon atoms), eicosanediamine (20 carbon atoms), heneicosanediamine (21 carbon atoms), docosanediamine (22 carbon atoms), tricosanediamine (23 carbon atoms), tetracosanediamine (24 carbon atoms), pentacosanediamine (25 carbon atoms), hexacosanediamine (26 carbon atoms), heptacosanediamine (27 carbon atoms), octacosanediamine (28 carbon atoms), nonacosanediamine (29 carbon atoms), triacontanediamine (30 carbon atoms), hentriacontanediamine (31 carbon atoms), dotriacontanediamine (32 carbon atoms), tritriacontanediamine (33 carbon atoms), tetratriacontanediamine (34 carbon atoms), pentatriacontanediamine (35 carbon atoms), dimer diamine (36 carbon atoms). The dimer diamine is a compound obtained by reducing and aminating (reductive amination) dimer acid. The dimer diamine may be a diamine having an unsaturated bond or a diamine whose unsaturation degree is reduced by a hydrogenation reaction, depending on the purpose of use. The aliphatic diamine may be subjected to a hydrogenation reaction or may have a cyclic structure. The aliphatic diamine may have a branch or an unsaturated bond. A commercially available product of the aliphatic diamine having a branch is "Diamine H20" manufactured by Okamura Yushi Co., Ltd. Commercially available products of the dimer diamine include "Versamine 551" manufactured by BASF Japan Ltd., "Versamine 552" (hydrogenated product of Versamine 551) manufactured by BASF Japan Ltd., "PRIAMINE 1075" manufactured by Croda Japan Ltd., and "PRIAMINE 1074" manufactured by Croda Japan Ltd. The aliphatic diamine may be used alone or in combination of two or more of the above.

[0014] In addition, the aliphatic diamine may be an "imide-extended diamine". Here, the "imide-extended diamine" refers to a "polyimide having amino groups at both ends" obtained by reacting a tetracarboxylic dianhydride with an excessive amount of diamine and subjecting the reaction product to dehydration ring closure. Specific examples of the tetracarboxylic dianhydride include pyromellitic dianhydride (PMDA), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), 2,3,3′,4′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 4,4′-oxydiphthalic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride, 3-trifluoromethyl-1,2,4,5-pyromellitic dianhydride, 3,6-trifluoromethyl-1,2,4,5-pyromellitic dianhydride, 4,4´-hexafluoroisopropylidene-phthalic dianhydride (6FDA), etc. These may be used alone or in combination of two or more.

[0015] In the method for producing bismaleimide of the present invention, in a solvent and in the presence of two kinds of acid catalysts, an aliphatic diamine is reacted with maleic anhydride to obtain maleamic acid, and then the amic acid portion of maleamic acid is imidized to obtain bismaleimide. The maleic anhydride as the reaction substrate is used in an equimolar amount with respect to the amino group of the aliphatic diamine. The imidization is preferably carried out at the reflux temperature of the used solvent while azeotropically removing the water generated by the imidization. The reaction temperature during the imidization is preferably 150 °C or lower, more preferably 130 °C or lower. The reaction time during the imidization is preferably 2 hours or more and 12 hours or less, more preferably 4 hours or more and 10 hours or less. When the reaction time exceeds 12 hours, side reactions such as the formation of vinyl polymers may easily occur. Also, when it is less than 2 hours, the imidization reaction does not proceed sufficiently, making washing difficult and the yield may decrease.

[0016] As acid catalysts, it is necessary to use two types of acid catalysts in combination. As the first acid catalyst, one with an acid dissociation constant (pKa) of less than 1 is used, and as the second acid catalyst, one with a pKa of 1 or more is used. For acids with a valence of 2 or more, the first acid dissociation constant (pKa1) is used as the pKa of this acid for the selection of the above acid catalysts.

[0017] Specifically, as the first acid catalyst, inorganic acids such as sulfuric acid (pKa: -3), nitric acid (pKa: -1.4), and organic sulfonic acids such as methanesulfonic acid (pKa: -2.6), toluenesulfonic acid (pKa: -2.8) can be used. Among them, methanesulfonic acid and toluenesulfonic acid are preferred.

[0018] As the second acid catalyst, those with a pKa of 1 to 7 are preferably used, and various organic carboxylic acids such as aliphatic carboxylic acids can be exemplified. As the second acid catalyst, aliphatic carboxylic acids such as acetic acid (pKa: 4.6), propionic acid (pKa: 4.9), maleic acid (pKa: 1.8), succinic acid (pKa: 4.2), malic acid (pKa: 3.4), fumaric acid (pKa: 3.0) can be exemplified. In addition, aliphatic acid anhydrides can be used as the second acid catalyst as chemically equivalent substances of aliphatic carboxylic acids. Examples of aliphatic acid anhydrides include acid anhydrides of acetic acid, propionic acid, maleic acid, succinic acid, malic acid, etc. Among the above carboxylic acids or acid anhydrides, maleic acid, malic acid, acetic acid and their acid anhydrides are preferred.

[0019] The total amount of the two types of acid catalysts used should be 115 mol% or more, preferably 150 mol% or more, based on the aliphatic diamine in moles. When the total amount of the acid catalysts used is less than 115 mol%, the effect of promoting the progress of the maleimidation reaction becomes insufficient. Also, when the amount of the acid catalysts used is large, the effect saturates. Therefore, considering economy, it is preferably 650 mol% or less, and more preferably 520 mol% or less. The amounts of the first acid catalyst and the second acid catalyst used are appropriately determined within the range of the above total amount. As the amount of the first acid catalyst used, the range of 55 mol% to 285 mol% is preferable, and the range of 85 mol% to 230 mol% is more preferable, based on the moles of the aliphatic diamine. Two or more types of the first acid catalyst may be used. In that case, their total amount used may be within the range of the amount of the first acid catalyst used described above. As the amount of the second acid catalyst used, the range of 55 mol% to 365 mol% is preferable, and the range of 65 mol% to 285 mol% is more preferable, based on the moles of the aliphatic diamine. Two or more types of the second acid catalyst may be used. In that case, their total amount used may be within the range of the amount of the second acid catalyst used described above. The usage ratio of the first acid catalyst and the second acid catalyst is not particularly limited, but the range of (the first acid catalyst) / (the second acid catalyst) = 2 / 8 to 8 / 2 (molar ratio) is preferable, the range of 3 / 7 to 7 / 3 is more preferable, and the range of 4 / 6 to 6 / 4 is even more preferable. Particularly when maleic anhydride is used not only as a raw material for bismaleimide but also as the second acid catalyst, the amount of the second acid catalyst used with respect to the moles of the aliphatic diamine described above is the value obtained by subtracting twice the molar amount with respect to the moles of the aliphatic diamine from the total amount of maleic anhydride used (that is, the total amount of maleic anhydride used as a raw material for bismaleimide and the amount of maleic anhydride used as the second acid catalyst). It is sufficient that the value is within the range of the amount of the second acid catalyst used with respect to the moles of the aliphatic diamine described above.

[0020] By thus using the two types of acid catalysts in a specific amount in combination, the maleimidation reaction is promoted, by-products such as Michael adducts and vinyl polymers in the production process of bismaleimide are suppressed, and a solution of bismaleimide with a high NMR integral value ratio (B / A) can be obtained.

[0021] In the maleimidation reaction, a basic compound (for example, an aliphatic tertiary amine such as triethylamine) may be allowed to coexist for the purpose of improving the yield. However, such a basic compound is considered to form a salt by a neutralization reaction with an acid catalyst and deactivate a part of the added acid catalyst. Therefore, in the maleimidation reaction of the present invention, it is preferable not to use a basic compound. When a basic compound is allowed to coexist, the total amount of the two types of acid catalysts used with respect to the mole of the aliphatic diamine is the value obtained by subtracting the amount of the basic compound used with respect to the mole of the aliphatic diamine from the total amount used. It is sufficient that the value is within the range of the total amount of the two types of acid catalysts used with respect to the mole of the aliphatic diamine described above.

[0022] The solvent used in the reaction is not limited as long as it is a solvent that dissolves the product bismaleimide. However, amide solvents such as N-methylpyrrolidone (NMP) and dimethylacetamide (DMAc), hydrocarbon solvents such as toluene and xylene, and ether solvents such as glyme and diglyme are preferably used. These solvents are used alone or in combination of two or more. Among these, a mixed solvent composed of an amide solvent and a hydrocarbon solvent is preferably used. The mixing ratio is not particularly limited, but in order to be 150 ° C or lower, which is the above-described preferable reaction temperature, a range of (amide solvent) / (hydrocarbon solvent) = 5 / 5 to 1 / 9 (mass ratio) is preferably used.

[0023] The solid content concentration during the reaction is preferably 20 to 70% by mass, and more preferably 30 to 70% by mass. The solid content concentration is the mass% of the total mass of the reaction substrates (aliphatic diamine and maleic anhydride) with respect to the mass of the charged solution (total mass of the reaction substrates, solvent, and acid catalyst).

[0024] The bismaleimide solution obtained as described above can be purified to reduce the acid value. In this case, for example, a method as described in JP-A-2018-115156 can be adopted. That is, in a solvent, a carbodiimide compound (CDI) is reacted with the acid component in the bismaleimide, whereby the acid value of the bismaleimide can be reduced to, for example, 2 mg-KOH / g or less. The amount of CDI used is not particularly limited as long as the carbodiimide group is 1 equivalent or more with respect to the acid value according to the acid value of the bismaleimide, and can be appropriately selected, for example, in the range of 1 to 1.2 equivalents. The reaction temperature is preferably 30°C to 100°C, more preferably 40°C to 70°C. The solid content concentration of the bismaleimide is preferably 20 to 70% by mass, more preferably 30 to 70% by mass, based on the solution mass. By this reaction, the acid component in the bismaleimide reacts with CDI, and a urea derivative of CDI is by-produced. This urea derivative of CDI can be removed by washing the reaction solution with water, alcohol (such as methanol, ethanol, etc.), that is, by solvent extraction. Thereafter, the solvent is distilled off to obtain a bismaleimide having an acid value of 2 mg-KOH / g or less. The acid value of the purified bismaleimide is more preferably 1 mg-KOH / g or less, and even more preferably 0.5 mg-KOH / g or less.

[0025] As the CDI to react with the acid component in bismaleimide, N,N′-diisopropylcarbodiimide (DIC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), bis(2,6-diisopropylphenyl)carbodiimide, diphenylcarbodiimide, di-β-naphthylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, di-t-butylcarbodiimide, N,N′-dicyclohexylcarbodiimide (DCC), poly(1,6-hexamethylenecarbodiimide), poly(4,4′-methylenebiscyclohexylcarbodiimide), poly(1,3-cyclohexylenecarbodiimide), poly(1,4-cyclohexylenecarbodiimide), poly(4,4′-dicyclohexylmethanecarbodiimide), poly(4,4′-diphenylmethanecarbodiimide), poly(3,3′-dimethyl-4,4′-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(tolylcarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(1,3,5-triisopropylbenzene carbodiimide), poly(1,3,5-triisopropylbenzene and 1,5-diisopropylbenzene carbodiimide), poly(triethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylcarbodiimide), etc. can be used, and DIC or EDC is preferred. These CDIs can be used alone or in combination of two or more.

[0026] There is no restriction on the solvent used for the reaction between the acid component in bismaleimide and CDI, but hydrocarbon solvents such as toluene, xylene (o-xylene, m-xylene, p-xylene), ethylbenzene, mesitylene, solvent naphtha, etc. are preferred.

[0027] The bismaleimide of the present invention can be used as a resin composition by being blended with epoxy resins, phenolic resins, unsaturated bond-containing compounds, benzoxazine compounds, polyimide resins, polyamideimide resins, etc. The blending amount is determined according to the purpose of use and is not particularly limited. For example, it is in the range of 5 to 50 parts by mass in 100 parts by mass of the resin composition.

[0028] Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, polyoxynaphthylene type epoxy resin, bisphenol A novolak type epoxy resin, biphenyl type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, xylene novolak type epoxy resin, polyfunctional phenol type epoxy resin, naphthalene type epoxy resin, naphthalene skeleton-modified novolak type epoxy resin, naphthylene ether type epoxy resin, phenol aralkyl type epoxy resin, anthracene type epoxy resin, trifunctional phenol type epoxy resin, tetrafunctional phenol type epoxy resin, triglycidyl isocyanurate, glycidyl ester type epoxy resin, alicyclic epoxy resin, dicyclopentadiene novolak type epoxy resin, biphenyl novolak type epoxy resin, phenol aralkyl novolak type epoxy resin, naphthol aralkyl novolak type epoxy resin, aralkyl novolak type epoxy resin, biphenyl aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, polyol type epoxy resin, phosphorus-containing epoxy resin, glycidylamine, and compounds obtained by epoxidizing double bonds such as butadiene.

[0029] Examples of the phenolic resin include bisphenol A type phenolic resin, bisphenol E type phenolic resin, bisphenol F type phenolic resin, bisphenol S type phenolic resin, phenol novolak resin, bisphenol A novolak type phenolic resin, glycidyl ester type phenolic resin, aralkyl novolak type phenolic resin, biphenyl aralkyl type phenolic resin, cresol novolak type phenolic resin, polyfunctional phenolic resin, naphthol resin, naphthol novolak resin, polyfunctional naphthol resin, anthracene type phenolic resin, naphthalene skeleton-modified novolak type phenolic resin, phenol aralkyl type phenolic resin, naphthol aralkyl type phenolic resin, dicyclopentadiene type phenolic resin, biphenyl type phenolic resin, alicyclic phenolic resin, polyol type phenolic resin, phosphorus-containing phenolic resin, hydroxyl group-containing silicone resins, and the like.

[0030] Examples of the unsaturated bond-containing compound include vinyl compounds such as ethylene, propylene, styrene, divinylbenzene, and divinylbiphenyl; (meth)acrylates of monohydric or polyhydric alcohols such as methyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; epoxy (meth)acrylates such as bisphenol A type epoxy (meth)acrylate and bisphenol F type epoxy (meth)acrylate, and the like.

[0031] Examples of the benzoxazine compound include 6,6-(1-methylethylidene)bis(3,4-dihydro-3-phenyl-2H-1,3-benzoxazine), 6,6-(1-methylethylidene)bis(3,4-dihydro-3-methyl-2H-1,3-benzoxazine), etc. Examples of commercially available products include "Benzoxazine F-a type" and "Benzoxazine P-d type" manufactured by Shikoku Chemicals Corporation, "RLV-100" manufactured by Air Water, etc.

[0032] The resin composition containing the bismaleimide of the present invention can be used in a wide range of applications, such as the core substrate and coverlay film of FPC, copper-clad laminate, passivation film, protective film, and interlayer insulating film on the surface of semiconductor elements of semiconductor devices, conformal coating of printed circuit boards, surface protective film of solar cells, alignment film of liquid crystal surface elements, protective film of glass fibers, printing paste composition, conductive paste composition, etc.

Examples

[0033] Hereinafter, the present invention will be described in more detail with reference to examples. Note that the present invention is not limited by the examples.

[0034] <Acid value> Measured by the neutralization titration method based on the provisions of JIS K0070 (1992). Approximately 1.0 g of bismaleimide was precisely weighed, diluted with THF so that the bismaleimide concentration was approximately 2% by mass, bromothymol blue (BTB) was used as an indicator, titration was performed with potassium hydroxide (KOH), and the value obtained by converting the number of mg of KOH consumed for neutralization per 1 g of bismaleimide was used.

[0035] <Example 1> 1) Preparation of bismaleimide solution In a glass reaction vessel equipped with a reflux condenser with a water separator, a stirrer, and a thermometer, under a nitrogen atmosphere, a mixed solvent consisting of toluene and NMP (mass ratio: toluene / NMP = 80 / 20), diamine H20 (manufactured by Okamura Yushi Co., Ltd., molecular weight: 331): 0.17 mol, maleic anhydride: 0.34 mol, p-toluenesulfonic acid: 0.15 mol (88 mol% based on the diamine) as the first acid catalyst, and maleic anhydride: 0.22 mol (129 mol% based on the same) as the second acid catalyst were charged and stirred. The resulting solution was heated with stirring to reflux the contents. After continuing the reflux at about 125 °C for 6 hours while azeotropically separating the water generated by the reaction, it was cooled to obtain a two-phase orange-yellow solution. Then, the upper phase of the obtained solution was taken out and washed twice with an aqueous solvent to obtain a bismaleimide solution having a solid content concentration of 30% by mass with toluene as the solvent. Bismaleimide (A-1) was obtained by distilling off the solvent. The acid value of this bismaleimide was 8.7 mg-KOH / g. This bismaleimide was 1 The results of measuring 1H-NMR under the conditions described above are shown in Fig. 1. As shown in Fig. 1, this 1 Using the integral value (A) of peak 1 (δ: about 3.5 ppm, multiplet) and the integral value (B) of peak 2 (δ: about 6.7 ppm, singlet) observed in the 1H-NMR chart, a quantitative comparison was performed, and as a result, B / A was 0.89.

[0036] <Example 1a> 2) Reduction of acid value by CDI In a glass reaction vessel equipped with a stirrer and a thermometer, under a nitrogen atmosphere, 200 g of the bismaleimide solution obtained in Example 1, 1.3 g of N,N'-diisopropylcarbodiimide (DIC) (1.05-fold equivalent based on the acid value of the crude bismaleimide), and methyl alcohol were charged and heated at 60 °C for 60 minutes, then cooled to obtain an orange-yellow solution. The obtained solution was purified by washing twice with an aqueous solvent, and bismaleimide (A-1a) was obtained by distilling off the solvent. The acid value of this bismaleimide was 0.95 mg-KOH / g. The 1 As a result of performing a quantitative comparison in the 1H-NMR of this bismaleimide, B / A was 0.89.

[0037] <Example 2> The second acid catalyst was made maleic acid: 0.12 mol (71 mol% of the same), and the procedure was the same as in Example 1 to obtain bismaleimide (A-2).

[0038] <Example 3> The procedure was the same as in Example 1 except that diamine H20 was changed to dimerdiamine ("Priamine 1074" manufactured by Clariant Japan Co., Ltd., molecular weight: 547), and bismaleimide (A-3) was obtained.

[0039] <Example 4> Diamine H20 was changed to dimerdiamine ("Priamine 1074" manufactured by Clariant Japan Co., Ltd., molecular weight: 547), the first acid catalyst was made methanesulfonic acid: 0.31 mol (182 mol% of the same), and the second acid catalyst, maleic anhydride: 0.32 mol (188 mol% of the same), and the procedure was the same as in Example 1 to obtain bismaleimide (A-4).

[0040] <Example 5> The procedure was the same as in Example 1 except that diamine H20 was changed to 1,10-decanediamine, and bismaleimide (A-5) was obtained.

[0041] <Example 6> Diamine H20 was changed to 1,10-decanediamine, the first acid catalyst was made methanesulfonic acid: 0.31 mol (182 mol% of the same), and the second acid catalyst was made maleic acid: 0.26 mol (153 mol% of the same), and the procedure was the same as in Example 1 to obtain bismaleimide (A-6).

[0042] <Example 7> In a glass reaction vessel equipped with a reflux condenser with a water separator, a stirrer, and a thermometer, under a nitrogen atmosphere, a mixed solvent consisting of toluene and NMP (mass ratio: toluene / NMP = 80 / 20), 0.11 mol of diamine H20 (manufactured by Okamura Yushi Co., Ltd., molecular weight: 331), 0.06 mol of PMDA, and 0.05 mol of p-toluenesulfonic acid as an acid catalyst were charged and stirred. The obtained solution was heated while stirring to reflux the contents. While azeotropically separating the water generated by the reaction, it was refluxed at about 125 °C for 3 hours to obtain 0.05 mol of diamine H20 extended with imide by PMDA (as the imide-extended diamine). The reaction mixture was cooled to room temperature, and 0.10 mol of maleic anhydride, 0.02 mol of additional p-toluenesulfonic acid as the first acid catalyst (the total with the previous addition amount as the first acid catalyst is 0.07 mol, 140 mol% based on the imide-extended diamine), and 0.05 mol of maleic anhydride as the second acid catalyst (100 mol%) were charged and stirred. The mixture was refluxed for an additional 6 hours and cooled to obtain a two-phase orange-yellow solution. Then, the upper phase of the obtained solution was taken out and washed twice with an aqueous solvent to obtain a bismaleimide solution with a solid content concentration of 30% by mass using toluene as the solvent. Bismaleimide (A-7) was obtained by distilling off the solvent.

[0043] <Example 8> Using 0.05 mol of methanesulfonic acid as the acid catalyst for the imide extension reaction of the diamine and 0.06 mol of additional methanesulfonic acid added during the maleimidation reaction of the imide-extended diamine (the total as the first acid catalyst is 0.11 mol, 220 mol% based on the imide-extended diamine), and using 0.14 mol of maleic anhydride as the second acid catalyst (280 mol%), the procedure was carried out in the same manner as in Example 7 to obtain bismaleimide (A-8).

[0044] <Comparative Example 1> The procedure was carried out in the same manner as in Example 1 except that the first acid catalyst was 0.31 mol of methanesulfonic acid (182 mol% based on the diamine) and the second acid catalyst was not used, to obtain bismaleimide (B-1).

[0045] <Comparative Example 2> The procedure of Example 1 was repeated, except that the first acid catalyst was not used and the second acid catalyst was maleic anhydride at 0.32 mol (188 mol %), to obtain bismaleimide (B-2).

[0046] <Comparative Example 3> The procedure of Example 1 was repeated, except that the first acid catalyst was methanesulfonic acid at 0.09 mol (53 mol %) and the second acid catalyst, maleic anhydride, was at 0.10 mol (59 mol %), to obtain bismaleimide (B-3).

[0047] <Comparative Example 4> The procedure of Example 3 was repeated, except that the first acid catalyst was not used and the second acid catalyst was maleic anhydride at 0.32 mol (188 mol %), to obtain bismaleimide (B-4).

[0048] <Comparative Example 5> The procedure of Example 5 was repeated, except that the first acid catalyst was methanesulfonic acid at 0.09 mol (53 mol %) and the second acid catalyst, maleic anhydride, was at 0.10 mol (59 mol %), to obtain bismaleimide (B-5).

[0049] <Comparative Example 6> The procedure of Example 7 was repeated, except that the acid catalyst used in the imide extension reaction of diamine was 0.05 mol of p-toluenesulfonic acid, and an additional 0.05 mol of p-toluenesulfonic acid (total as the first acid catalyst was 0.10 mol, 200 mol % based on the imide-extended diamine) was added during the maleimidation reaction of the imide-extended diamine, and the second acid catalyst was not used, to obtain bismaleimide (B-6).

[0050] <Comparative Example 7> Triethylamine (38.45 g, 0.380 mol) was added to toluene (200 mL), and methanesulfonic acid (37.44 g, 0.390 mol) was added dropwise with stirring. After stirring at room temperature for 30 minutes, maleic anhydride (25.90 g, 0.264 mol) was added, and then diamine H20 (34.42 g, 0.104 mol) was added dropwise. After stirring at room temperature for 30 minutes, the mixture was refluxed at 110 °C for 8 hours to remove water in the system. The obtained reaction solution was washed with brine, filtered through silica gel, and then toluene was distilled off under reduced pressure to obtain bismaleimide (B-7).

[0051] The usage amounts of the acid catalysts in the examples and comparative examples and the evaluation results of the obtained bismaleimides are shown in Table 1.

[0052]

Table 1

[0053] As shown in the examples, the bismaleimide of the present invention uses two specific catalysts in combination during synthesis, so that the NMR integral value ratio (B / A) in 1H-NMR, which is an index of the progress of the maleimidation reaction, is significantly improved. That is, the maleimide group content in the bismaleimide increases, and when an aliphatic diamine reacts with maleic acid, the formation of by-products such as Michael adducts and vinyl polymers is suppressed. In contrast, in each comparative example, the NMR integral value ratio (B / A) is low, indicating that the progress of maleimidation is not sufficient. When triethylamine, a basic compound, is used together with an acid catalyst during the synthesis of bismaleimide as in Comparative Example 7, the acid catalyst is neutralized, and thus the combined effect of the catalysts cannot be obtained. 1

Industrial Applicability

[0054] The bismaleimide of the present invention has a sufficiently reduced generation of by-products. Therefore, it is industrially advantageous when compounded with other agents, and can be suitably used as a component of a sealing material composition, an adhesive composition, etc. used in the manufacture of electronic components using semiconductors and the like.​

Claims

1. A bismaleimide in which the amino groups of an aliphatic diamine are maleimidized, １ A bismaleimide in which, when quantitative comparison is carried out using the integral value (A) of the peak corresponding to the proton of the methylene group directly bonded to the nitrogen atom of the maleimide group and the integral value (B) of the peak corresponding to the vinyl proton of the maleimide group in 1H-NMR, B / A is more than 0.

80.

2. A method for producing bismaleimide according to claim 1, characterized in that an acid having a pKa of less than 1 and an acid having a pKa of 1 or more are used as catalysts in an amount of 115 mol% or more based on the moles of the aliphatic diamine.

3. The method for producing bismaleimide according to claim 2, further comprising a step of reacting the obtained bismaleimide with a carbodiimide compound (CDI).

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