bismaleimide

Abstract

The present invention provides a bismaleimide in which acid components derived from a by-product is sufficiently reduced and which also has improved coatability to glass. The present invention pertains to a bismaleimide in which an amino group of a diamine formed of a reaction product of an aromatic tetracarboxylic acid dianhydride and a dimer diamine is converted into a maleimide, in which the molar ratio of the aromatic tetracarboxylic acid dianhydride to the dimer diamine is in the range of 0.2-0.45, and which has an acid value of 2 mg-KOH / g or less.

Description

Bismaleimide

[0001] The present invention relates to bismaleimides.

[0002] Electronic components used in electronic devices such as mobile phones, smartphones, and laptop computers are becoming increasingly highly integrated and mounted. Resin materials used in these electronic components, such as adhesives and encapsulants, are required to have low water absorption, excellent reliability, and heat resistance. A known method uses bismaleimide, in which the amino group of dimadiamine (an aliphatic diamine derived from a dimer acid having 24 to 48 carbon atoms, hereinafter abbreviated as "DDA") is maleimidized, as a component of the composition used in these adhesives, encapsulants, and the like. For example, Patent Document 1 discloses a method using maleimide as a component of an adhesive composition for mounting LED elements. Patent Document 2 discloses a method using bismaleimide as a component of an anisotropic conductive adhesive composition for printed wiring boards.

[0003] Aliphatic bismaleimides can be obtained by known methods disclosed in Patent Documents 3 to 5, etc. That is, they can be produced, for example, by reacting a diamine with maleic anhydride in a solvent in the presence of an acid catalyst, followed by imidization and purification. 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. These aliphatic bismaleimides contain trace amounts of uncyclized acid components, such as maleamic acid, fumaric acid, and Michael adducts (compounds formed by the Michael addition reaction of MAA with an amine, followed by further reaction with maleic anhydride), resulting in acid values ​​significantly exceeding 2 mg-KOH / g. These acid components have the problem of adversely affecting electronic components when used in electronic components. For example, when used as an adhesive or pressure-sensitive adhesive for semiconductors, bismaleimides can cause corrosion in semiconductor devices, and the acid component can increase the moisture absorption of bismaleimides, which can lead to deterioration of electrical properties.

[0004] As a solution to the above problem, Patent Documents 6 and 7 describe a production method in which an aliphatic bismaleimide having a relatively high acid value and containing residual acid components (crude bismaleimide) is produced, and then impurities such as maleamic acid are removed by reacting the bismaleimide with a carbodiimide compound (CDI) to reduce the acid value to 2 mg-KOH / g or less.

[0005] Japanese Patent Application Laid-Open No. 2017-31227 Japanese Patent Application Laid-Open No. 2015-193725 US Statutory Invention Registration H424 US Publication No. 20080262191 Special Publication No. Hei 10-505599 Japanese Patent Application Laid-Open No. 2018-115156 Japanese Patent Application Laid-Open No. 2019-001784

[0006] However, even in bismaleimides in which impurities derived from acids such as maleamic acid have been reduced and the acid value has been reduced to 2 mg-KOH / g or less, there is still a problem: the reduced acid value leads to a deterioration in wettability to glass, impairing coatability.

[0007] The present invention is intended to solve the above problems and has as its object to provide a bismaleimide that has a sufficiently reduced amount of acid components derived from by-products and that also has improved applicability to glass.

[0008] The present inventors have found that the above-mentioned problems can be solved by using a bismaleimide consisting of an imide-extended dimadiamine obtained by condensing dimadiamine with an aromatic tetracarboxylic dianhydride in a specific molar ratio, and have thus completed the present invention.

[0009] That is, the gist of the present invention is as follows: A bismaleimide in which the amino group of the diamine formed as a reaction product of an aromatic tetracarboxylic dianhydride with a diamine containing dimadiamine as a main component is maleimidized, the molar ratio of the aromatic tetracarboxylic dianhydride to the dimadiamine being in the range of 0.2 to 0.45, and the bismaleimide having an acid value of 2 mg-KOH / g or less.

[0010] The present invention further comprises: １The bismaleimide has a ratio A / B of 1.2 to 7.5 when quantitatively comparing an integral value (A) of a peak corresponding to a proton of a methylene group directly bonded to a nitrogen atom of the maleimide group and an integral value (B) of a peak corresponding to a proton of a methylene group directly bonded to a nitrogen atom of the imide group in H-NMR.

[0011] The present invention further relates to the above bismaleimide, wherein the viscosity of the bismaleimide measured at 25°C with a Brookfield viscometer is 15 Pa·s or more and 200 Pa·s or less.

[0012] The bismaleimide of the present invention has a reduced acid value and exhibits good applicability to glass, and is therefore suitable for use in the manufacture of electronic components using semiconductors and the like, as a component of encapsulant compositions, adhesive compositions, and the like.

[0013] The bismaleimide of Example 1 １ 1 H-NMR chart.

[0014] The present invention will be described in detail below. The bismaleimide of the present invention is a reaction product (dehydration condensation product) of a diamine, primarily composed of dimer diamine (DDA), with an aromatic tetracarboxylic dianhydride, in which an oligoimide terminal diamine is maleimidized. DDA is an aliphatic diamine having 24 to 48 carbon atoms derived from a dimer acid having 24 to 48 carbon atoms. DDA may contain a double bond derived from the raw material in its structure, or may be hydrogenated. Dimer acid is a fatty acid primarily composed of a dibasic acid of a dicarboxylic acid (e.g., a dicarboxylic acid having 24 to 48 carbon atoms, particularly 36 carbon atoms) produced by dimerization of an unsaturated fatty acid (e.g., a 12 to 24 (especially 18) carbon atom unsaturated fatty acid) derived from vegetable oils and fats. As the DDA, commercially available products such as "Versamin 551" manufactured by Cognis Japan Co., Ltd., and "Priamine 1074" and "Priamine 1075" manufactured by Croda Co., Ltd. can be used.

[0015] The diamine used in the bismaleimide of the present invention is preferably dimadiamine, the main component of which is 80 mol % or more of the diamine. That is, diamines other than DDA may be used as long as the effects of the present invention are not impaired. Such other diamines include aromatic diamines, heterocyclic diamines, alicyclic diamines, and aliphatic diamines.

[0016] Aromatic diamines are diamine compounds having one or more aromatic rings in one molecule. Specific examples of such aromatic diamines include p-phenylenediamine (PDA), 4,4'-diaminodiphenyl ether (ODA), 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), m-phenylenediamine, 2,4-diaminotoluene, 2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene, 4,4'-diaminobiphenyl, 4,4'-diamino-2,2' -bis(trifluoromethyl)biphenyl (TFMB), 2,2'-dimethyl-4,4'-diaminobiphenyl (DMDB), 9,9-bis(4-aminophenyl)fluorene, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfide, p-xylylenediamine, m-xylylenediamine, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenyl ether , 3,3'-diaminodiphenyl ether, 1-(4-aminophenyl)-1,3,3-trimethylindan-5-amine, 1-(4-aminophenyl)-1,3,3-trimethylindan-6-amine, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-methylenebis(2, 6-diethylaniline), bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, and 4,4'-(piperazine-1,4-diyl)dianiline.

[0017] Heterocyclic diamines are diamine compounds that contain one or more heterocyclic rings and no aromatic rings in each molecule. Specific examples of such heterocyclic diamines include 1,4-bis(3-aminopropyl)piperazine.

[0018] Alicyclic diamines are diamine compounds that contain one or more alicyclic rings and no aromatic rings per molecule. Specific examples of such alicyclic diamines include 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)norbornane, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0(2,6)]decane, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, isophoronediamine, 4,4'-methylenebis(cyclohexylamine), and 4,4'-methylenebis(2-methylcyclohexylamine).

[0019] Aliphatic diamines are diamine compounds that do not contain any alicyclic rings, heterocyclic rings, or aromatic rings in one molecule. Specific examples of such aliphatic diamines include 1,4-diaminobutane, 1,10-diaminodecane, 1,12-diaminododecane, 1,7-diaminoheptane, 1,6-diaminohexane, 1,5-diaminopentane, 1,8-diaminooctane, 1,3-diaminopropane, 1,11-diaminoundecane, and 2-methyl-1,5-diaminopentane.

[0020] The bismaleimide of the present invention may or may not contain a diamine other than DDA as a diamine component. When the bismaleimide of the present invention contains another diamine, the other diamine preferably contains an aromatic diamine, from the viewpoints of further reducing the acid component and further improving the coatability on glass, thickness uniformity, and dielectric properties. The content of the other diamine (particularly the aromatic diamine) relative to the diamine component is preferably 20 mol % or less (particularly 15 mol % or less).

[0021] Specific examples of aromatic tetracarboxylic dianhydrides include 4,4'-oxydiphthalic anhydride (ODPA), pyromellitic dianhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride (BDCP), 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (BPADA), 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), 1,3,3a,4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione (TDA-100). These may be used alone or in combination of two or more. Of these, ODPA, PMDA, BPDA, and TDA-100 are preferred.

[0022] The molar ratio of aromatic tetracarboxylic dianhydride to diamine is in the range of 0.2 to 0.45, preferably 0.3 to 0.45, from the viewpoints of further reducing the acid component and further improving the glass coating property, thickness uniformity, and dielectric properties. If the molar ratio exceeds 0.45, the viscosity of the bismaleimide increases, which may result in poor handling during coating. If the molar ratio is less than 0.2, the improvement in glass wettability is insufficient, and defects in the coating film, such as repelling and thickness unevenness, may occur during coating or curing.

[0023] The molar ratio of aromatic tetracarboxylic dianhydride to diamine in the bismaleimide of the present invention can be calculated, for example, from the results of NMR measurement performed under the same conditions as those for measuring the NMR integral value ratio (A / B) described below.

[0024] When the chemical structure of the bismaleimide of the present invention is represented by, for example, the following general formula (I), the average value of n is 0.25 to 0.82, and the bismaleimide is considered to be a mixture of bismaleimides having structures with different degrees of polymerization, such as a structure where n is 0 and a structure where n is 1 or more (e.g., 1, 2, ...).

[0025]

[0026] In formula (I), R Ｄ is a residue derived from diamine. When the diamine constituting the bismaleimide of the present invention contains two or more diamines with different structures, R Ｄ is a mixed group of residues derived from the two or more diamines. Ｔ is a residue derived from the aromatic tetracarboxylic dianhydride. When the aromatic tetracarboxylic dianhydride constituting the bismaleimide of the present invention contains two or more aromatic tetracarboxylic dianhydrides having different structures, R Ｔ is a mixed group of residues derived from the two or more aromatic tetracarboxylic dianhydrides.

[0027] The acid value is a parameter that quantitatively represents the amount of acid component remaining in the bismaleimide, and a value measured by neutralization titration based on JIS K0070 (1992) can be used. From the viewpoint of the influence on electrical properties when used in electronic components, etc., the acid value of the bismaleimide of the present invention must be 2 mg-KOH / g or less, preferably 1 mg-KOH / g or less, and more preferably 0.5 mg-KOH / g or less. If the acid value is too high, the electrical properties (particularly the dielectric properties) will deteriorate when the bismaleimide is used in electronic components, etc.

[0028] From the viewpoints of further reducing the acid component and further improving the coatability on glass, thickness uniformity, and dielectric properties, the viscosity of the bismaleimide of the present invention, as measured with a Brookfield viscometer at 25° C., is preferably 10 Pa s or more and 200 Pa s or less, more preferably 15 Pa s or more and 200 Pa s or less, and even more preferably 30 Pa s or more and 200 Pa s or less. By doing so, good handleability and coatability on glass can be ensured.

[0029] In the production of bismaleimide, first, DDA and aromatic tetracarboxylic dianhydride are reacted in a solvent to obtain an amic acid, which is then imidized to obtain a terminal diamine oligoimide. Next, the oligoimide is reacted with maleic anhydride to obtain a terminal maleamic acid oligoimide, and then the maleamic acid moiety is imidized to obtain a bismaleimide. This typically results in a crude bismaleimide solution with an acid value of greater than 2 mg-KOH / g, containing residual by-products derived from the acid. Imidization is preferably carried out at the reflux temperature of the solvent used, while azeotropically removing the water produced by imidization. The reaction temperature during the imidization is preferably 150°C or less, more preferably 130°C or less. The reaction time during imidization is preferably 2 hours or more and 12 hours or less, and more preferably 4 hours or more and 10 hours or less. Reaction times exceeding 12 hours may increase the likelihood of side reactions, such as the formation of vinyl polymers. If the reaction time is less than 2 hours, the imidization reaction may not proceed sufficiently, making washing difficult and reducing the yield.

[0030] The solvent used in the reaction is not particularly limited as long as it dissolves the bismaleimide product. Preferred examples include 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. These solvents may be used alone or in combination of two or more. Among these, a mixed solvent consisting of an amide solvent and a hydrocarbon solvent is preferably used. The mixing ratio is not particularly limited, but a range of (amide solvent) / (hydrocarbon solvent) = 5 / 5 to 1 / 9 (mass ratio) is preferably used to achieve the aforementioned preferred reaction temperature of 150°C or less.

[0031] The solid content concentration during the reaction is preferably 20 to 70% by mass, more preferably 30 to 70% by mass, where the solid content concentration refers to the mass % of the total mass of the reaction substrates (DDA, aromatic tetracarboxylic dianhydride, and maleic anhydride) relative to the mass of the charged solution (the total mass of the reaction substrates, solvent, and dehydroxylation catalyst).

[0032] There are no particular limitations on the acid catalyst used in the dehydration ring-closure reaction of maleamic acid, but examples include sulfuric acid, methanesulfonic acid, benzenesulfonic acid, orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphorous acid, hypophosphorous acid, and maleic acid. These catalysts can be used alone or in combination of two or more. Triethylamine salts of these acids can also be used. During the dehydration ring-closure, it is preferable to remove water generated by maleimidization from the reaction system by azeotropy or the like. The amount of the acid catalyst used is not particularly limited, but can be in the range of 115 to 650 mol % based on the moles of DDA.

[0033] The bismaleimide obtained as described above can be purified by known methods, such as separation and washing, reprecipitation, and recrystallization, with separation and washing being preferred from the viewpoint of ease in the production process.

[0034] Furthermore, as one purification method, the obtained bismaleimide may be purified by removing acid components as impurities using a carbodiimide compound (CDI), as described in Patent Documents 6 and 7, etc. That is, CDI is reacted with the acid component in the bismaleimide in a solvent, and the urea derivative of CDI, which is a by-product of the reaction between the acid component in the bismaleimide and CDI, is removed by washing with water, alcohol (methanol, ethanol, etc.), etc., to obtain a bismaleimide with a low acid value. The amount of CDI used is not particularly limited as long as the carbodiimide group is at least 1 equivalent relative to the acid value, depending on the acid value of the bismaleimide, and can be appropriately selected, for example, within 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.

[0035] Examples of CDIs to be reacted with the acid component in the bismaleimide include 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 Examples of CDIs that can be used include 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(methyl-diisopropylphenylenecarbodiimide), poly(1,3,5-triisopropylbenzenecarbodiimide), poly(1,3,5-triisopropylbenzene and 1,5-diisopropylbenzenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), and poly(diisopropylcarbodiimide), with DIC or EDC being preferred. These CDIs may be used alone or in combination of two or more.

[0036] There are no limitations on the solvent used in the reaction between the acid component in the bismaleimide and CDI, but alcoholic solvents such as methyl alcohol and ethyl alcohol, and hydrocarbon solvents such as toluene, xylene (o-xylene, m-xylene, p-xylene), ethylbenzene, mesitylene, and solvent naphtha are preferred.

[0037] The bismaleimide thus obtained is １The NMR integral value ratio (A / B) in H-NMR is preferably 1.2 or more and 7.5 or less, more preferably 1.2 or more and 5.0 or less, and even more preferably 1.2 or more and 3.0 or less. 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 proton of the methylene group directly bonded to the nitrogen atom of the imide group. If the ratio (A / B) is less than 1.2, the viscosity will be high, and coatability and thickness uniformity will be impaired. If it exceeds 7.5, wettability to glass will be impaired.

[0038] The bismaleimide of the present invention can be suitably used in the production of electronic parts using semiconductors or the like, and as a component of sealing material compositions, adhesive compositions, and the like.

[0039] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0040] (1) Acid value of bismaleimide: This was measured by neutralization titration in accordance with JIS K0070 (1992). A bismaleimide solution was precisely weighed and diluted with THF to a bismaleimide concentration of approximately 2% by mass. The solution was titrated with potassium hydroxide (KOH) using bromothymol blue (BTB) as an indicator, and the number of milligrams of KOH consumed for neutralization was converted to a value per gram of bismaleimide.

[0041] (2) Viscosity of Bismaleimide The rotational viscosity at 25±0.2° C. was measured using a DVL-BII type digital viscometer (B-type viscometer) manufactured by Tokimec Co., Ltd.

[0042] (3) Coatability of Bismaleimide Bismaleimide was applied to the surface of a 0.7 mm thick alkali-free glass substrate (Corning "Eagle XG", 20 cm square) using a table coater so that the thickness after curing would be 50 μm, and the coating was cured by heating at 100° C. for 30 minutes, 150° C. for 30 minutes, and 230° C. for 90 minutes. After thermal curing, the presence or absence of cissing in the bismaleimide resin layer was visually confirmed. If no cissing was observed, it was marked with "○", and if cissing was observed, it was marked with "×".

[0043] (4) Thickness Uniformity of Bismaleimide Film The heat-cured bismaleimide film was peeled off from the glass substrate, and the thickness of the film was measured in 1 cm increments in the MD and TD directions using a dial gauge ("ID-C112CX" manufactured by Mitutoyo Corporation). If the maximum and minimum values ​​were within the range of 50 μm ± 5 μm, the result was marked "○", and if outside the range, the result was marked "×".

[0044] (5) Dielectric Properties of Bismaleimide Film A film of uniform thickness was used as a sample, and a disk resonator was created on one side of it. The dielectric loss tangent (Df) was measured at 10 GHz using a network analyzer (manufactured by Agilent Technologies). The measurement was performed three times for the same sample, and the average value was used as the measured value. A dielectric loss tangent of 0.0025 or less is within the practically acceptable range (acceptable range), and preferably 0.0022 or less.

[0045] (6) Measurement of NMR integral value ratio (A / B) Bismaleimide was measured under the following measurement conditions. １ For example, the bismaleimide of Example 1 was subjected to H-NMR measurement. １ The H-NMR chart is shown in Figure 1. The integral value of the peak corresponding to the proton of the methylene group directly bonded to the nitrogen atom of the maleimide group was designated "A." The integral value of the peak corresponding to the proton of the methylene group directly bonded to the nitrogen atom of the imide group was designated "B."

[0046] The NMR measurement conditions are as follows (see FIG. 1): １ H-NMR measurement conditions> Apparatus: Nuclear magnetic resonance apparatus (manufactured by JEOL Ltd.: Model No. ECA500) Frequency: 500.16 MHz Reference substance: tetramethylsilane Solvent: deuterated chloroform Measurement temperature: 25°C

[0047] Under the above measurement conditions, the chemical shift corresponding to the peak of the proton of the methylene group directly bonded to the nitrogen atom of the maleimide group of the bismaleimide is approximately 3.5 ppm (Peak 1 in Figure 1). Also, the chemical shift corresponding to the peak of the proton of the methylene group directly bonded to the nitrogen atom of the imide group of the bismaleimide is approximately 3.7 ppm (Peak 2 in Figure 1). Therefore, the NMR integral value ratio can be calculated by reading the integral values ​​of these peaks from the NMR chart.

[0048] Example 1 Preparation of Bismaleimide A mixed solvent of toluene and NMP (mass ratio: toluene / NMP = 80 / 20), 0.20 mol of dimerdiamine ("Priamine 1075" manufactured by Croda Japan Co., Ltd., molecular weight: 550), 0.09 mol of ODPA, and 0.18 mol of methanesulfonic acid as a catalyst were placed in a glass reaction vessel equipped with a reflux condenser with a water separator, a stirrer, and a thermometer under a nitrogen atmosphere and stirred (ODPA / dimerdiamine = 0.45 (molar ratio)). The resulting solution was heated to reflux while stirring. The contents were refluxed at approximately 125°C for 3 hours while azeotropically separating the water produced by the reaction, yielding an oligoimide. The reaction mixture was cooled to room temperature, and 0.44 mol of maleic anhydride was added to the reaction vessel, followed by 0.03 mol of methanesulfonic acid as a catalyst. The mixture was refluxed for an additional 12 hours, and the water produced by maleimide formation was removed from the reaction system. The mixture was then cooled to obtain a two-phase orange-yellow solution. The amount of maleic anhydride used was 200 mol % relative to the terminal amino groups of the oligoimide (the condensate of dimadiamine and dianhydride). 100 mol % was consumed to maleimide the amino groups, and the excess 100 mol % maleic anhydride was converted to maleic acid by the water produced by the reaction, acting as a dehydration ring-closing catalyst. The amount of maleic anhydride used was the same in the following examples and comparative examples.

[0049] [Purification of Bismaleimide] The upper phase of the resulting solution was then removed and washed twice with an aqueous solvent to obtain a bismaleimide solution. The acid value of this bismaleimide was 5.8 mg-KOH / g. Subsequently, 2.2 g of N,N'-diisopropylcarbodiimide (DIC) (an amount equivalent to 1.1 times the acid value of the bismaleimide) and methyl alcohol were added, and the mixture was heated at 60°C for 60 minutes and then cooled to obtain an orange-yellow solution. The resulting solution was purified by washing twice with an aqueous solvent, and the solvent was distilled off to obtain bismaleimide (A-1). The viscosity of this bismaleimide was 150 Pa·s and the acid value was 0.9 mg-KOH / g. Furthermore, １ The results of H-NMR measurement under the above conditions are shown in Figure 1. As shown in Figure 1, １A quantitative comparison was carried out using the integral value (A) of Peak 1 (δ: approximately 3.5 ppm multiplet) and the integral value (B) of Peak 2 (δ: approximately 3.7 ppm multiplet) observed in the H-NMR chart, and the A / B ratio was found to be 1.2.

[0050] Example 2 Bismaleimide (A-2) was obtained in the same manner as in Example 1, except that the amount of ODPA was 0.04 mol and the amount of maleic anhydride was 0.64 mol. The amount of maleic anhydride used in this example was an amount corresponding to 200 mol % relative to the terminal amino groups of the oligoimide as a condensate of dimadiamine and acid dianhydride, similar to the amount used in Example 1. The same applies to the subsequent examples and comparative examples.

[0051] Example 3 Bismaleimide (A-3) was obtained in the same manner as in Example 1, except that the amount of ODPA was 0.07 mol and the amount of maleic anhydride was 0.52 mol.

[0052] Example 4 Bismaleimide (A-4) was obtained in the same manner as in Example 1, except that PMDA was used instead of ODPA.

[0053] Example 5 Bismaleimide (A-5) was obtained in the same manner as in Example 1, except that ODPA was replaced with BPDA.

[0054] Example 6 Bismaleimide (A-6) was obtained in the same manner as in Example 1, except that PMDA was used instead of ODPA, and the amount of PMDA was 0.04 mol and the amount of maleic anhydride was 0.64 mol.

[0055] Example 7 Bismaleimide (A-7) was obtained in the same manner as in Example 1, except that PMDA was used instead of ODPA, and the amount of PMDA was 0.07 mol and the amount of maleic anhydride was 0.52 mol.

[0056] Example 8 Bismaleimide (A-8) was obtained in the same manner as in Example 1, except that ODPA was replaced with BPDA, and the amount of BPDA was 0.04 mol and the amount of maleic anhydride was 0.64 mol.

[0057] Example 9 Bismaleimide (A-9) was obtained in the same manner as in Example 1, except that ODPA was replaced with BPDA, and the amount of BPDA was 0.07 mol and the amount of maleic anhydride was 0.52 mol.

[0058] Example 10 Bismaleimide (A-10) was obtained in the same manner as in Example 1, except that ODPA was changed to 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione (trade name "TDA-100", manufactured by New Japan Chemical Co., Ltd.).

[0059] Example 11 Bismaleimide (A-11) was obtained in the same manner as in Example 1, except that ODPA was replaced with TDA-100, the amount of TDA-100 was 0.04 mol, and the amount of maleic anhydride was 0.64 mol.

[0060] Example 12 Bismaleimide (A-12) was obtained in the same manner as in Example 1, except that dimadiamine was changed to "Priamine 1074" (molecular weight 547) manufactured by Croda Japan Co., Ltd.

[0061] Example 13 Bismaleimide (A-13) was obtained in the same manner as in Example 1, except that dimadiamine was changed to Priamine 1074, the amount of ODPA was changed to 0.04 mol, and the amount of maleic anhydride was changed to 0.64 mol.

[0062] Example 14 Bismaleimide (A-14) was obtained in the same manner as in Example 1, except that the amount of dimadiamine was changed from 0.20 mol to 0.18 mol, 4,4′-diamino-2,2′-bis(trifluoromethyl)biphenyl (TFMB) was changed to 0.02 mol, ODPA was changed to 0.07 mol, and the amount of maleic anhydride was changed to 0.52 mol.

[0063] Example 15 Bismaleimide (A-15) was obtained in the same manner as in Example 1, except that 0.09 mol of ODPA was replaced with 0.07 mol of ODPA and 0.02 mol of PMDA.

[0064] Comparative Example 1 Bismaleimide (B-1) was obtained in the same manner as in Example 1, except that the amount of ODPA was 0.11 mol and the amount of maleic anhydride was 0.36 mol.

[0065] Comparative Example 2 Bismaleimide (B-2) was obtained in the same manner as in Example 1, except that ODPA was not used and the amount of maleic anhydride was changed to 0.80 mol.

[0066] Comparative Example 3 In Example 1, after maleimidation, the product was simply washed twice with an aqueous solvent, and bismaleimide (B-3) was obtained without reacting with DIC.

[0067] Comparative Example 4 In Example 2, after maleimidation, the product was simply washed twice with an aqueous solvent, and bismaleimide (B-4) was obtained without reacting with DIC.

[0068] The oligoimide compositions of the bismaleimides obtained in the examples and comparative examples and the molar ratios of aromatic tetracarboxylic dianhydride to DDA are shown in Table 1, and the evaluation results of viscosity, acid value, coatability, thickness uniformity, and dielectric loss tangent, as well as NMR quantitative comparisons are shown in Table 2.

[0069]

[0070]

[0071] As shown in the examples, the bismaleimide of the present invention has a reduced acid value and exhibits good glass coatability, thickness uniformity, and dielectric properties when the molar ratio of aromatic tetracarboxylic dianhydride to DDA is set within a specific range. Comparative Example 1, in which the molar ratio is 0.55, exhibits high viscosity and poor coatability and thickness uniformity. Even in the case of Comparative Example 2, in which no aromatic tetracarboxylic dianhydride is used, the glass wettability is low and the coatability and thickness uniformity are poor. Comparative Examples 3 and 4 exhibit poor dielectric properties because the acid value is not reduced.

[0072] The bismaleimide of the present invention has a reduced acid value and exhibits good applicability to glass, and is therefore suitable for use in the manufacture of electronic components using semiconductors and the like, as a component of encapsulant compositions, adhesive compositions, and the like.

Claims

1. A bismaleimide in which the amino group of the diamine, which is a reaction product of an aromatic tetracarboxylic dianhydride with a diamine mainly composed of dimadiamine, is maleimidized, the molar ratio of the aromatic tetracarboxylic dianhydride to the dimadiamine being in the range of 0.2 or more and 0.45 or less, and the acid value being 2 mg-KOH / g or less.

2. １ 2. The bismaleimide according to claim 1, wherein, in H-NMR, a quantitative comparison is performed using an integral value (A) of a peak corresponding to a proton of a methylene group directly bonded to a nitrogen atom of the maleimide group and an integral value (B) of a peak corresponding to a proton of a methylene group directly bonded to a nitrogen atom of the imide group, and the A / B is 1.2 or more and 7.5 or less.

3. The bismaleimide according to claim 1 or 2, wherein the viscosity of the bismaleimide measured at 25° C. by a Brookfield viscometer is 15 Pa·s or more and 200 Pa·s or less.

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