Process for producing a maleimide resin

Abstract

A method for producing a maleimide resin, the maleimide resin being a maleimide resin obtained by reacting a tetracarboxylic dianhydride (a1), an amine (a2), and maleic anhydride (a3), the method for producing the maleimide resin comprising the steps of: obtaining a polyimide resin by adding the amine (a2) to the tetracarboxylic dianhydride (a1) in the presence of an organic solvent; and obtaining the maleimide resin by adding the maleic anhydride (a3) to the polyimide resin, the organic solvent containing at least one of gamma-butyrolactone and N-ethyl-2-pyrrolidone, the amine (a2) containing a dimer diamine and a second amine other than the dimer diamine.

Description

Technical Field

[0001] This invention relates to a method for manufacturing maleimide resin. Background Technology

[0002] Printed circuit boards and multilayer circuit boards using printed circuit boards are used in mobile communication devices such as mobile phones and smartphones, their base station devices, network-related electronic equipment such as servers / routers, and large computers.

[0003] In recent years, high-frequency electrical signals have been used in these products for high-speed transmission / processing of large amounts of information. However, high-frequency signals are very easy to attenuate. Therefore, in order to suppress transmission loss, insulating materials with excellent dielectric properties are required as insulating materials used in the aforementioned printed circuit boards and multilayer circuit boards.

[0004] As the aforementioned insulating material, epoxy resin compositions disclosed in Patent Documents 1 to 3 are known. Patent Document 1 discloses an epoxy resin composition containing epoxy resin, an active ester compound, and a triazine-containing cresol phenolic varnish resin, which is effective for achieving low dielectric loss tangent. Furthermore, Patent Documents 2 and 3 disclose resin compositions with epoxy resin and an active ester compound as essential components that can form cured products with low dielectric loss tangent, making them useful as insulating materials. However, it has been found that these epoxy resin compositions are unsuitable for high-frequency band applications.

[0005] On the other hand, Patent Document 4 reports a resin film composed of a resin composition exhibiting excellent dielectric properties (low relative permittivity and low dielectric loss tangent). This resin composition contains a bismaleimide resin with long-chain alkyl groups and a curing agent as a non-epoxy material. However, bismaleimide resins composed solely of long-chain alkyl diamines suffer from low Tg and low elastic modulus.

[0006] Previous technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2011-132507 Patent Document 2: Japanese Patent Application Publication No. 2015-101626 Patent Document 3: Japanese Patent Application Publication No. 2017-210527 Patent Document 4: International Publication No. 2016 / 114287 Summary of the Invention

[0007] The technical problem to be solved by the invention As a maleimide resin capable of forming a cured product with low dielectric constant and low dielectric loss tangent, and high elastic modulus and high Tg, the inventors have studied maleimide resins obtained using dimer diamines and other amines as amines.

[0008] The object of this invention is to provide a novel manufacturing method for producing a specific maleimide resin. In particular, the object of this invention is to provide a manufacturing method for producing a maleimide resin that enables the resin composition to have good storage stability.

[0009] means for solving technical problems To achieve the above objectives, the present invention provides the following method for manufacturing maleimide resin.

[0010] [1] A method for manufacturing a maleimide resin, wherein the maleimide resin is a maleimide resin obtained by reacting tetracarboxylic dianhydride (a1), amine (a2) and maleic anhydride (a3), and the manufacturing method comprises the following steps: adding the amine (a2) to the tetracarboxylic dianhydride (a1) in the presence of an organic solvent to obtain a polyimide resin; and adding the maleic anhydride (a3) ​​to the polyimide resin to obtain a maleimide resin, wherein the organic solvent comprises at least one of γ-butyrolactone and N-ethyl-2-pyrrolidone, and the amine (a2) comprises dimerized diamine and a second amine other than dimerized diamine.

[0011] [2] According to the manufacturing method of maleimide resin described in [1] above, wherein, At least one of the above-mentioned tetracarboxylic dianhydride (a1) and the above-mentioned amine (a2) comprises a compound having a fluorene skeleton.

[0012] [3] According to the manufacturing method of maleimide resin described in [1] or [2] above, wherein, The aforementioned tetracarboxylic acid dianhydride (a1) comprises at least one of 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 9,9-bis(3,4-dicarboxyphenyl)fluorenic anhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorenic anhydride, and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride.

[0013] [4] The method for manufacturing maleimide resin according to any one of [1] to [3] above, wherein, The aforementioned second amine contains at least one of norbornene diamine, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, and 9,9-bis(4-aminophenyl)fluorene.

[0014] [5] The method for manufacturing maleimide resin according to any one of [1] to [4] above, wherein, The above-mentioned dimer diamine contains at least one of the compounds represented by the following general formula (1) and the compounds represented by the following general formula (2).

[0015] [In equations (1) and (2), m, n, p, and q represent integers greater than 1 selected in the manner of m+n=6~17 and p+q=8~19, respectively. The bonds represented by dashed lines refer to carbon-carbon single bonds or carbon-carbon double bonds. Among them, when the bonds represented by dashed lines are carbon-carbon double bonds, equations (1) and (2) have the following structure: the structure obtained by subtracting 1 from the number of hydrogen atoms bonded to each carbon atom constituting the carbon-carbon double bond as shown in equations (1) and (2).] [6] The method for manufacturing maleimide resin according to any one of [1] to [5] above, wherein, It is prepared by reacting the above tetracarboxylic acid dianhydride (a1) with 0.30 to 1.00 moles relative to 1.00 moles of the above amine (a2).

[0016] [7] The method for manufacturing maleimide resin according to any one of [1] to [6] above, wherein, The aforementioned organic solvents further include aromatic hydrocarbons with a boiling point of 150°C or higher.

[0017] [8] The method for manufacturing maleimide resin according to any one of [1] to [7] above, wherein, The aforementioned organic solvents further include alcohols with boiling points below 100°C.

[0018] [9] The method for manufacturing maleimide resin according to any one of [1] to [8] above, wherein, Based on the total amount of organic solvents, the content of the above-mentioned γ-butyrolactone and N-ethyl-2-pyrrolidone in the above-mentioned organic solvents is 5 to 40% by mass.

[0019] Invention Effects According to the present invention, a novel manufacturing method for producing a specific maleimide resin is provided. In particular, according to the present invention, a manufacturing method for producing a maleimide resin that exhibits good storage stability in the resin composition is provided. Furthermore, the maleimide resin produced by the manufacturing method of the present invention, and the resin composition (adhesive composition) using the maleimide resin, can jointly reduce the dielectric constant and dielectric loss tangent (hereinafter, both are sometimes collectively referred to as "dielectric properties"). Especially, the low dielectric properties in the high-frequency band are excellent, and a cured product with high elastic modulus and high Tg can be formed. The cured product (adhesive layer) obtained from the above-described resin composition has a high elastic modulus and Tg, therefore, the above-described resin composition is useful as an adhesive used in the manufacture of printed circuit boards (additional substrates, flexible printed circuit boards, etc.) and copper foil for printed circuit boards, and is also useful as an insulating film such as a rewiring layer, a semiconductor interlayer material, a coating agent, a resist ink, a conductive paste, etc. Attached Figure Description

[0020] Figure 1 This is the IR spectrum of the maleimide resin (A-1) synthesized in Example 1.

[0021] Figure 2 This is the IR spectrum of the maleimide resin (A-2) synthesized in Example 2. Detailed Implementation

[0022] The preferred embodiments of the present invention will now be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be implemented within its scope.

[0023] In this specification, the numerical range indicated by "~" represents the range encompassed by the values ​​before and after "~" as the minimum and maximum values, respectively. Within the numerical ranges described in stages in this specification, the upper or lower limit of a certain stage's numerical range can be arbitrarily combined with the upper or lower limits of other stages' numerical ranges. Within the numerical ranges described in this specification, the upper or lower limit of the numerical range can be replaced with the values ​​shown in the examples. "A or B" may include either A or B, or both. Unless otherwise specified, the materials exemplified in this specification can be used alone or in combination with two or more. When multiple substances belonging to each component exist in the composition, unless otherwise specified, the content of each component in the composition refers to the total amount of the multiple substances present in the composition. In this specification, "solid component" refers to the non-volatile component contained in the resin composition after removing volatile substances (water, solvents, etc.), and also includes components that are liquid, syrupy, or waxy at room temperature (around 25°C).

[0024] <Manufacturing Method of Maleimide Resin> The method for manufacturing maleimide resin according to this embodiment is a method for producing maleimide resin by reacting tetracarboxylic dianhydride (a1) (hereinafter also referred to as "(a1) component"), amine (a2) (hereinafter also referred to as "(a2) component"), and maleic anhydride (a3) ​​(hereinafter also referred to as "(a3) component"). The manufacturing method includes the following steps: adding the amine (a2) to the tetracarboxylic dianhydride (a1) in the presence of an organic solvent to obtain a polyimide resin; and adding the maleic anhydride (a3) ​​to the polyimide resin to obtain a maleimide resin. Here, the organic solvent includes at least one of γ-butyrolactone and N-ethyl-2-pyrrolidone. Furthermore, the amine (a2) includes dimerized diamine and a second amine other than dimerized diamine.

[0025] (a1) Component: Tetracarboxylic acid dianhydride) As component (a1), tetracarboxylic dianhydride can be any known raw material used in polyimide. Examples of components (a1) include pyromellitic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 4,4'-oxobisphthalic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, and 3,3',4,4'-biphenyltetracarboxylic dianhydride. Carboxylic acid dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)phthalic anhydride, 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, bicyclo[2.2.2]oct-7-ene-2 3,5,6-Tetracarboxylic acid dianhydride, bis(1,3-dioxo-1,3-dihydroxyisobenzofuran-5-carboxylic acid)1,4-phenylene, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 4,4'-(acetylene-1,2-diyl)diphthalic anhydride, 5-(2,5-dioxotetrahydrofuranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, dicyclohexyl-3,4,3',4'-tetracarboxylic acid dianhydride Citric acid dianhydrides, 3,4'-oxobisphthalic anhydride, 3,4'-diphthalic anhydride, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid dianhydride, 5,5'-bis-2-norbornene-5,5',6,6'-tetracarboxylic acid-5,5',6,6'-dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, etc. They can be used alone or in combination of two or more.

[0026] From the viewpoint of low dielectric properties, high Tg, or low coefficient of linear expansion (CTE), the (a1) component is preferably composed of 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)phthalic anhydride, 4,4'-(hexafluoroisophthalic acid) Propylene) phthalic anhydride, 5-(2,5-dioxotetrahydrofuranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, dicyclohexyl-3,4,3',4'-tetracarboxylic anhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic acid 2,3:5,6-dianhydride, 5,5'-bis-2-norbornene-5,5',6,6'-tetracarboxylic acid-5,5',6,6'-dianhydride, 3,4'-phthalic anhydride and 9,9-bis[4-(3,4-dicarboxyphenyl) [4,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 9,9-bis(3,4-dicarboxyphenyl)fluorenic anhydride, 4,4'-(4,4'-isopropylidenediphenoxy)phthalic anhydride, 4,4'-(hexafluoroisopropylidene)phthalic anhydride, 9,9-bis[4-(3,4-dicarboxyphenyl)fluorenic anhydride] It contains at least one of the following groups: 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 9,9-bis(3,4-dicarboxyphenyl)fluorenic anhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorenic anhydride, and 3,3',4,4'-biphenyltetracarboxylic anhydride.

[0027] (a2) The component contains a dimerized diamine (the first amine) and a second amine other than the dimerized diamine.

[0028] For example, as described in Japanese Patent Application Publication No. 9-12712, dimer diamines are compounds derived from dimers of unsaturated fatty acids such as oleic acid, i.e., dimer acids. By using dimer diamines as component (a2), the dielectric properties of the cured product can be reduced. In this embodiment, known dimer diamines can be used without particular limitation. Dimer diamines are preferably, for example, compounds represented by the following general formula (1) and compounds represented by the following general formula (2).

[0029] [In equations (1) and (2), m, n, p, and q represent integers greater than 1 selected in the manner of m+n=6~17 and p+q=8~19, respectively. The bonds represented by dashed lines refer to carbon-carbon single bonds or carbon-carbon double bonds. Among them, when the bonds represented by dashed lines are carbon-carbon double bonds, equations (1) and (2) have the following structure: the structure obtained by subtracting 1 from the number of hydrogen atoms bonded to each carbon atom constituting the carbon-carbon double bond as shown in equations (1) and (2).] As a dimer, diamine can be represented by the above general formula (2) from the viewpoint of solubility in organic solvents, heat resistance, heat-resistant adhesion, low viscosity, etc., and in particular, it can be a compound represented by the following formula (3).

[0030] Commercially available products as dimerized diamines include, for example, PRIAMINE 1075 and PRIAMINE 1074 (both manufactured by Croda Japan KK). They can be used alone or in combination of two or more.

[0031] The second amine is an amine that does not correspond to the aforementioned dimer diamine. The second amine can be a diamine or a triamine, or simply a diamine. Using an alicyclic diamine as the second amine can further reduce the dielectric constant. Using an aromatic diamine as the second amine improves the elastic modulus, Tg, and CTE of the cured product.

[0032] When the second amine is a diamine, examples of such diamines include 1,3-diaminopropane, norbornene diamine, 4,4'-methylenediphenylamine, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis[3-fluoro-4-aminophenyl]fluorene, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)norbornene, 4,4'-(hexafluoroisopropylidene)diphenylamine, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0] 2,6Decane, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, isophoronediamine, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), 1,1-bis(4-aminophenyl)cyclohexane, 2,7-diaminofluorene, 4,4'-ethylidene diphenylamine, 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(2-ethyl-6-methylaniline), 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]methane, 4,4'-bis(4-) Bis[4-(4-aminophenoxy)phenyl] ether, bis[4-(4-aminophenoxy)phenyl] ketone, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2'-dimethylbiphenyl-4,4'-diamine, (4,4'-diamino)diphenyl ether, (3,3'-diamino)diphenyl ether, p-phenylenediamine, o-phenylenediamine, m-phenylenediamine, 2,2'-dimethylbiphenyl-4,4'-diamine, bis[4-(3-aminophenoxy)phenyl] sulfone, bis[4-(4-aminophenoxy)phenyl] sulfone, etc. They can be used alone or in combination of two or more.

[0033] When the second amine is a triamine, examples of such triamines include tris(aminomethyl)amine, tris(2-aminoethyl)amine, tris(2-aminopropyl)amine, 2-(aminomethyl)-2-methyl-1,3-propanediamine, trimeric triamine, 3,4,4'-triaminodiphenyl ether, 1,2,4-triaminobenzene, 1,3,5-triaminobenzene, 1,2,3-triaminobenzene, 1,3,5-triazine-2,4,6-triamine, 2,4,6-triaminopyrimidine, 1,3,5-tris(4-aminophenyl)benzene, and 1,3,5-tris(4-aminophenoxy)benzene. These can be used alone or in combination of two or more. From the viewpoint of the solubility of the synthesized maleimide resin in organic solvents, aliphatic triamines are preferred; furthermore, from the viewpoint of achieving high Tg, tris(aminomethyl)amine and tris(2-aminoethyl)amine, which have fewer carbon atoms, are more preferred.

[0034] The second amine may include one or both of the aforementioned diamines and triamines. Furthermore, the second amine may include amines other than diamines and triamines.

[0035] From the viewpoint of high Tg, high elastic modulus and low CTE, the second amine is preferably containing at least one of norbornene diamine, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene and 9,9-bis(4-aminophenyl)fluorene.

[0036] In component (a2), the molar ratio of the second amine relative to the total amount of amine (moles of the second amine / (moles of the dimer diamine + moles of the second amine)) can be 70 mol% or less, or 50 mol% or less. If this ratio is 70 mol% or less, the dielectric properties of the cured product can be further reduced.

[0037] When the second amine contains a diamine, in component (a2), the molar ratio of the diamine in the second amine relative to the total amount of diamine (moles of diamine in the second amine / (moles of dimer diamine + moles of diamine in the second amine)) can be 70 mol% or less, or 50 mol% or less. If this ratio is 70 mol% or less, the dielectric properties of the cured material can be further reduced.

[0038] By using a dimerized diamine as the diamine, the dielectric properties of the cured product can be reduced. On the other hand, when only a dimerized diamine is used as the amine, the elastic modulus and Tg of the cured product decrease. In contrast, by using a second amine (especially a diamine other than a dimerized diamine) in combination with the dimerized diamine, the elastic modulus and Tg of the cured product can be increased while maintaining its dielectric properties.

[0039] At least one of the aforementioned components (a1) and (a2) may contain a compound having a fluorene framework. By having at least one of the components (a1) and (a2) constituting the maleimide resin contain a compound having a fluorene framework, the cured product obtained using this maleimide resin achieves high elastic modulus, high Tg, and low CTE while sufficiently maintaining a low dielectric constant and low dielectric loss tangent. From the viewpoint of further improving the elastic modulus and Tg of the cured product and reducing CTE, both of the aforementioned components (a1) and (a2) may contain a compound having a fluorene framework.

[0040] Maleimide resins can be manufactured by the following method. For example, firstly, components (a1) and (a2) are subjected to an addition polymerization reaction typically for about 0.1 to 2 hours (preferably 0.1 to 1.0 hours) at a temperature of about 60 to 120°C (preferably 70 to 90°C). Next, the obtained addition polymer is subjected to an imidization reaction, i.e., a dehydration and ring-closing reaction (imidization step), at a temperature of about 80 to 250°C (preferably 100 to 200°C) for about 0.5 to 30 hours (preferably 0.5 to 10 hours). The imidization step is carried out in the presence of an organic solvent containing at least one of γ-butyrolactone and N-ethyl-2-pyrrolidone. Next, the substance that has undergone the dehydration and ring-closure reaction is subjected to a maleimide reaction (maleimide closure step) with component (a3) ​​at a temperature of about 60–250°C (preferably 80–200°C) for about 0.5–30 hours (preferably 0.5–10 hours). This yields the desired maleimide resin. The addition polymerization, imide closure, and maleimide closure reactions can be carried out under atmospheric pressure, reduced pressure, or increased pressure.

[0041] The organic solvent used in this embodiment includes at least one of γ-butyrolactone and N-ethyl-2-pyrrolidone. By using at least one of γ-butyrolactone and N-ethyl-2-pyrrolidone, a maleimide resin with good storage stability of the resin composition can be produced. Here, it is believed that the good storage stability of the resin composition is achieved because, by using the aforementioned organic solvent, a maleimide resin with a low amine value can be obtained, thereby suppressing reactions in the resin composition.

[0042] From the viewpoint of improving the storage stability of the resin composition, the content of γ-butyrolactone and N-ethyl-2-pyrrolidone in the organic solvent (the total content when both γ-butyrolactone and N-ethyl-2-pyrrolidone are included) is preferably 5% by mass or more, more preferably 8 to 40% by mass, and particularly preferably 8 to 25% by mass, based on the total amount of organic solvent.

[0043] The organic solvent can be a mixture of multiple organic solvents, which may include organic solvents other than γ-butyrolactone and N-ethyl-2-pyrrolidone. From the viewpoint of easily dissolving components (a1) and (a2) in the mixed solvent, shortening the reaction time of the dehydration ring-closure reaction in the imidization and maleimide processes, and synthesizing maleimide resins in a short time, the mixed solvent preferably contains aromatic hydrocarbons with a boiling point of 150°C or higher. Furthermore, from the viewpoint of enabling half-esterification of component (a1), the mixed solvent preferably contains an alcohol with a boiling point of 100°C or lower. Half-esterification of component (a1) facilitates its dissolution in the mixed solvent, promotes the dehydration ring-closure reaction in the imidization process, and suppresses side reactions. Moreover, by using an alcohol with a boiling point of 100°C or lower, the alcohol component is easily removed during the dehydration ring-closure reaction in the imidization process, increasing the ring-closure rate of imidization and shortening the reaction time. In addition, the boiling point in this specification refers to the boiling point at atmospheric pressure (1013 hPa).

[0044] Examples of aromatic hydrocarbons with boiling points above 150°C include solvent oils, mesitylene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene (Pseudocumene), and tetrahydronaphthalene. Among these, solvent oils, mesitylene, and 1,2,4-trimethylbenzene are preferred from the viewpoint of boiling point. They can be used alone or in combination of two or more.

[0045] The boiling point of the aforementioned aromatic hydrocarbons is 150°C or higher, but from the viewpoint of achieving efficient synthesis in a shorter time, it can be 155°C or higher, or even 160°C or higher. On the other hand, from the viewpoint of further reducing the amount of solvent remaining in the synthesized maleimide resin, the boiling point of the aforementioned aromatic hydrocarbons can be 210°C or lower, or 200°C or lower, or even 180°C or lower.

[0046] Examples of alcohols with boiling points below 100°C include methanol, ethanol, 1-propanol, and isopropanol. These can be used alone or in combination of two or more. Among these, methanol and ethanol are particularly preferred from the viewpoint of ease of removal during imide ring closure. Here, the ease of hydrolysis of esters generally depends on the number of carbon atoms (boiling point) of the alcohol; the lower the boiling point of the alcohol, the higher the removal ability and the easier it is to remove the imide during ring closure. Therefore, methanol and ethanol are preferred as alcohols.

[0047] The mixed solvent may include other solvents besides those mentioned above. Examples of other solvents include methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, ethylene glycol monomethyl ether, N,N'-dimethylformamide, N-methylcaprolactam, methyl triethylene glycol dimethyl ether, methyl diethylene glycol dimethyl ether, 1-butanol, benzyl alcohol, cresol, propylene glycol monomethyl ether, methyl isobutyl methanol, 1-propoxy-2-propanol, cyclopentanone, cyclohexanone, and methylcyclohexane. These solvents can be used alone or in combination of two or more. Based on the total amount of the mixed solvent, the content of these other solvents may be less than 10% by mass.

[0048] In imidization or maleimide reactions, various known reaction catalysts and dehydrating agents can be used. Examples of reaction catalysts include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, heterocyclic tertiary amines such as pyridine, methylpyridine, and isoquinoline, and organic acids such as methanesulfonic acid and p-toluenesulfonic acid monohydrate. These can be used alone or in combination of two or more. Examples of dehydrating agents include aliphatic anhydrides such as acetic anhydride and aromatic anhydrides such as benzoic anhydride. These can also be used alone or in combination of two or more.

[0049] The manufacturing method of this embodiment may include a water washing step after the maleimide annealing step, in which the obtained maleimide resin is purified by washing with water. The water washing can be performed by adding the obtained maleimide resin and an organic solvent together to water and stirring, separating the stirred mixture into an aqueous layer and an oil layer (organic layer), and removing the aqueous layer. This series of operations can be repeated more than twice. Furthermore, the water washing can be performed at a liquid temperature of 50–100°C. By performing the water washing step, ionic impurities can be removed. The oil layer containing the recovered maleimide resin can be heated to remove water. The maleimide resin after water removal can be heated to remove the solvent. The solvent removal can also be performed under reduced pressure. The reduced pressure can be achieved by heating at a temperature of 80–150°C for 0.2–10.0 hours under a pressure reduced from atmospheric pressure by 0.06–0.10 MPa.

[0050] The maleimide resin obtained by the manufacturing method of this embodiment can have multiple maleimide groups within the molecule. The maleimide resin can be a bismaleimide resin. The hypothetical structure of the maleimide resin manufactured by the above method is shown in the following general formula (4). General formula (4) assumes that the second amine is a diamine.

[0051] In general formula (4), X independently represents a tetravalent organic group, Y independently represents a divalent organic group, and a represents an integer greater than or equal to 1. At least one of the plurality of Y groups represents a divalent organic group derived from the aforementioned dimer diamine, and at least one of the plurality of Y groups represents a divalent organic group derived from the aforementioned second amine (diamine). Furthermore, X and Y can be aliphatic groups, organic groups with alicyclic structures, or aromatic rings, and these can contain heteroatoms. Moreover, at least one of X and Y can be an organic group with a fluorene skeleton.

[0052] The molecular weight of the maleimide resin can be controlled by the molar numbers of components (a1) and (a2). The smaller the molar number of component (a1) is compared to the molar number of component (a2), the greater the reduction in molecular weight. For the purpose of easily achieving the effects of the present invention, the molar number of component (a1) relative to 1.00 moles of component (a2), i.e., [molar number of component (a1)] / [molar number of component (a2)], can typically be in the range of about 0.30 to 1.00 (preferably 0.30 to 0.95, more preferably 0.30 to 0.90, and even more preferably 0.50 to 0.80).

[0053] From the viewpoint of solubility in solvents and heat resistance, the molecular weight of maleimide resin, expressed as a weight-average molecular weight (Mw), is preferably 3,000 to 30,000, more preferably 3,000 to 25,000, even more preferably 5,000 to 23,000, and particularly preferably 7,000 to 20,000. There is a tendency that if the weight-average molecular weight is below 30,000, the solubility in organic solvents becomes good, and if it is above 3,000, the effect of improved heat resistance is sufficiently obtained. Mw can be determined by gel permeation chromatography (GPC) and converted using a calibration curve of standard polystyrene.

[0054] From the viewpoint of improving the storage stability of resin compositions containing this maleimide resin, the amine value of the maleimide resin is preferably 1.5 mg KOH / g or less, more preferably 1.0 mg KOH / g or less, and particularly preferably 0.6 mg KOH / g or less. The manufacturing method of this embodiment enables the production of maleimide resins with reduced amine values.

[0055] <Resin Composition> Maleimide resin can be used as a resin composition. The resin composition can be a photosensitive resin composition. In this case, the photosensitive resin composition is coated and dried on a substrate to form a resin film, and the resin film is exposed and developed to obtain a patterned resin film (a patterned resin film). Then, by heating and curing the patterned resin film, a patterned cured film (a patterned cured film) can be formed, which can be used as an insulating film. The following description pertains to the case where the resin composition is a photosensitive resin composition.

[0056] The photosensitive resin composition contains the aforementioned maleimide resin (hereinafter also referred to as "component (A)"). In the photosensitive resin composition, one type of maleimide resin can be used alone or in combination of two or more types. The photosensitive resin composition may further contain a crosslinking agent and a photopolymerization initiator. Furthermore, the photosensitive resin composition may, as needed, contain a thermal polymerization initiator, a coupling agent, a rust inhibitor, a polymerization inhibitor, etc. The photosensitive resin composition according to this embodiment is a negative photosensitive resin composition, and the cured product of the photosensitive resin composition can preferably be used as an insulating film for a redistribution layer. Hereinafter, the components used in the photosensitive resin composition of this embodiment will be described in more detail.

[0057] (Cross-linking agent) The crosslinking agent (hereinafter also referred to as "component (B)") can be a polymerizable crosslinking agent. The polymerizable group can be a photopolymerizable group or a thermopolymerizable group. Examples of polymerizable groups include (meth)acryloyl, allyl, and vinyl. Component (B) can be a multifunctional compound having two or more polymerizable groups. Furthermore, component (B) can crosslink with each other and with component (A) not only when the resin composition is exposed. Furthermore, component (B) can crosslink with each other by the polymerizable crosslinking agent when the resin film after patterning is heated. Component (B) can be used alone or in combination of two or more.

[0058] From the viewpoint of dielectric properties, the resin composition according to this embodiment may contain a polymerizable crosslinking agent having (meth)acrylyl groups as a crosslinking agent. When the photosensitive layer is exposed, the polymerizable crosslinking agent having (meth)acrylyl groups can crosslink not only with itself but also with component (A). The polymerizable crosslinking agent having (meth)acrylyl groups may be an acrylate compound or a methacrylate compound. From the viewpoint of dielectric properties, component (B) may contain a methacrylate compound.

[0059] Examples of polymerizable crosslinking agents having (meth)acryloyl groups include tricyclodecanediethanol di(meth)acrylate, tri-(2-(meth)acryloyloxyethyl)isocyanurate, dioxaneglycol di(meth)acrylate, alkoxylated glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, alkoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, alkoxylated pentaerythritol tetra(meth)acrylate, 1, 6-Hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A (meth)acrylate, dipentaerythritol poly(meth)acrylate, alkoxylated dipentaerythritol poly(meth)acrylate, ethoxylated isocyanurate tri(meth)acrylate, polyethylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate.

[0060] From the viewpoint of heat resistance, dielectric properties and microprocessability, a polymerizable crosslinking agent having a (meth)acrylyl group may include at least one selected from the group consisting of tricyclodecanediethanol di(meth)acrylate, tri-(2-(meth)acryloxyethyl)isocyanurate and dioxaneglycol di(meth)acrylate, and from the viewpoint of heat resistance and dielectric properties, may include tri-(2-(meth)acryloxyethyl)isocyanurate.

[0061] From the viewpoint of dielectric properties and heat resistance, the resin composition involved in this embodiment may contain a polymerizable crosslinking agent having allyl or vinyl groups as a crosslinking agent. When the resin film after patterning is heated, the polymerizable crosslinking agents having allyl or vinyl groups can crosslink with each other.

[0062] Examples of polymerizable crosslinking agents containing allyl groups include 1,3,4,6-tetraallyl glycidyl urea, triallyl isocyanurate, diallyl monoglycidyl isocyanurate, diallyl monomethyl isocyanurate, diallyl isocyanurate, triallyl trimellitate, and triallyl orthoformate.

[0063] Examples of polymerizable crosslinking agents containing vinyl groups include polyvinylbenzyl compounds and polyvinylbenzyl ether compounds.

[0064] From the viewpoint of dielectric properties and microprocessability, polymerizable crosslinking agents having allyl or vinyl groups may include at least one selected from the group consisting of 1,3,4,6-tetraallyl glycourea, triallyl isocyanurate, diallyl isocyanurate, and polyvinyl benzyl ether compounds, and may also include triallyl isocyanurate.

[0065] From the perspective of further improving the balance between low dielectric properties and microprocessability, when the total amount of component (A) and component (B) is set to 100 parts by mass, the content of component (B) is preferably less than 50 parts by mass, which can be 1 to 45 parts by mass, 5 to 40 parts by mass, 8 to 30 parts by mass or 10 to 20 parts by mass.

[0066] (Photopolymerization initiator) As a photopolymerization initiator (hereinafter also referred to as "component (C)"), there are no particular restrictions as long as it is a compound that begins to polymerize by irradiation with active light (such as ultraviolet light), but examples include alkyl phenyl ketone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, intramolecular hydrogen abstraction photopolymerization initiators, and oxime ester photopolymerization initiators.

[0067] Alkylphenyl ketone-based photopolymerization initiators, such as Omnirad 651, Omnirad 184, Omnirad 1173, Omnirad 2959, Omnirad 127, Omnirad 907, Omnirad 369, and Omnirad 379EG manufactured by IGM Resins BV, are available for purchase. Acylphosphine oxide-based photopolymerization initiators, such as Omnirad 819 and Omnirad TPO H manufactured by IGM Resins BV, are available for purchase. Intramolecular hydrogen abstraction photopolymerization initiators, such as Omnirad MBF and Omnirad 754 manufactured by IGM Resins BV, are available for purchase. Oxime ester-based photopolymerization initiators, such as Irgacure OXE01 and Irgacure OXE02 manufactured by BASF Japan Ltd., are available for purchase. To promote the photoreaction, a diacetic photopolymerization initiator (e.g., Irgacure 784 manufactured by BASF Japan Ltd.) can be used.

[0068] From the viewpoint of easily obtaining excellent microprocessability, the content of component (C) relative to the total amount of components (A) and (B) 100 parts by mass can be 0.1 to 10 parts by mass, 0.5 to 8 parts by mass, or 1 to 5 parts by mass.

[0069] (Thermal polymerization initiator) From the viewpoint of promoting the polymerization reaction of the thermopolymerizable crosslinking agent, the photosensitive resin composition according to this embodiment may further contain a thermopolymerization initiator as component (D). As component (D), it is preferably a compound that decomposes upon heating during curing to generate free radicals and promote the polymerization reaction of components (A) and (B). Examples of components (D) include organic peroxides.

[0070] Examples of organic peroxides include methyl ethyl ketone peroxide, methyl cyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-hexylperoxy)cyclohexane, 1,1-bis(tert-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(4,4-di-tert-butylperoxycyclohexyl)propane, 1,1-bis(tert-butylperoxy)cyclododecane, n-butyl-4,4-bis(tert-butylperoxy)valerate, 2,2-bis(tert-butylperoxy)butane, and 1,1-bis( tert-Butylperoxy)-2-methylcyclohexane, tert-Butyl hydroperoxide, p-Menthane hydroperoxide, 1,1,3,3-Tetramethylbutyl hydroperoxide, tert-Hexyl hydroperoxide, dicumyl peroxide, 2,5-Dimethyl-2,5-bis(tert-Butylperoxy)hexane, α,α'-bis(tert-Butylperoxy)diisopropylbenzene, tert-Butylisopropylbenzene peroxide, di-tert-Butyl peroxide, 2,5-Dimethyl-2,5-bis(tert-Butylperoxy)hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, cinnamic acid peroxide, m-Toluyl (m -Toluoyl) peroxide, benzoyl peroxide, diisopropylperoxydicarbonate, bis(4-tert-butylcyclohexyl)peroxydicarbonate, di-3-methoxybutylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, di-sec-butylperoxydicarbonate, di(3-methyl-3-methoxybutyl)peroxydicarbonate, di(4-tert-butylcyclohexyl)peroxydicarbonate, α,α'-bis(neodecanylperoxy)diisopropylbenzene, isopropylbenzene peroxyneodecanate, 1,1,3,3'-tetramethylbutylperoxyneodecanate, 1-cyclohexyl-1-methylethylperoxyneodecanate, tert-hexylperoxyneodecanate, tert-butylperoxyneodecanate Oxylated neodecanoate, tert-hexylperoxyneopentate, tert-butylperoxyneopentate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, tert-hexylperoxy-2-ethylhexanoate, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyisobutyrate, tert-butylperoxymaleate, tert-butylperoxylaurate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxyisopropyl monocarbonate, tert-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-Bis(benzoylperoxy)hexane, tert-butylperoxyacetate, tert-hexylperoxybenzoate, tert-butylperoxym-tolylbenzoate, tert-butylperoxybenzoate, bis(tert-butylperoxy)isophthalate, tert-butylperoxyallyl monocarbonate, and 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone.

[0071] The content of component (D) is not particularly limited, but it can be 0.1 to 10.0 parts by mass, 0.5 to 5.0 parts by mass, or 0.7 to 3.0 parts by mass relative to the total amount of components (A) and (B) per 100 parts by mass.

[0072] (Coupled agent) From the viewpoint of improving the adhesion of the cured photosensitive resin composition, the photosensitive resin composition according to this embodiment may further contain a coupling agent. The coupling agent may be a silane coupling agent. For example, the silane coupling agent may have groups such as vinyl, epoxy, styrene, acryloyl, methacryloyl, amino, urea, isocyanate, isocyanurate, mercapto.

[0073] Examples of vinyl-containing silane coupling agents include KBM-1003 and KBE-1003 (product names manufactured by Shin-Etsu Chemical Co., Ltd. The same applies hereinafter). Examples of epoxy-containing silane coupling agents include KBM-303, 402, 403, KBE-402, 403, X-12-981S, and X-12-984S. Examples of styrene-containing silane coupling agents include KBM-1403. Examples of methacrylyl-containing silane coupling agents include KBM-502, 503, KBE-502, and 503. Examples of acryloyl-containing silane coupling agents include KBM-5103, X-12-1048, and X-12-1050. Examples of silane coupling agents containing amino groups include KBM-602, 603, 903, 573, 575, KBE-903, 9103P, and X-12-972F. Examples of silane coupling agents containing urea groups include KBE-585. Examples of silane coupling agents containing isocyanate groups include KBE-9007 and X-12-1159L. Examples of silane coupling agents containing isocyanurate groups include KBM-9659. Examples of silane coupling agents containing mercapto groups include KBM-802, 803, X-12-1154, and X-12-1156. Silane coupling agents can also be silane coupling agents containing methacryl groups. Silane coupling agents can be used alone or in combination of two or more.

[0074] The content of the silane coupling agent relative to the total amount of components (A) and (B) per 100 parts by mass can be 0.01 to 10 parts by mass, 0.1 to 8 parts by mass, or 0.5 to 5 parts by mass.

[0075] (Rust inhibitor) From the viewpoint of inhibiting corrosion of copper wiring or preventing discoloration of copper wiring, the photosensitive resin composition according to this embodiment may further contain a rust inhibitor. Examples of rust inhibitors include triazole derivatives such as benzotriazole and tetraazole derivatives. One type of rust inhibitor may be used alone, or two or more may be used in combination.

[0076] The content of the rust inhibitor relative to the total amount of components (A) and (B) per 100 parts by mass can be 0.01 to 10 parts by mass, 0.1 to 5 parts by mass, or 0.5 to 3 parts by mass.

[0077] (Polymerization inhibitor) From the viewpoint of preservation stability, the photosensitive resin composition involved in this embodiment may further contain polymerization inhibitors.

[0078] Examples of polymerization inhibitors include 4-tert-butylcatechol, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxo radical, p-methoxyphenol, diphenyl-p-benzoquinone, benzoquinone, hydroquinone, gallnutol, phenothiazine, resorcinol, o-dinitrobenzene, p-dinitrobenzene, m-dinitrobenzene, phenanthraquinone, N-phenyl-2-naphthylamine, copper ferroin, 2,5-toluquinone, tannic acid, p-benzylaminophenol, tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid, and nitrosamines. Polymerization inhibitors can be used alone or in combination of two or more.

[0079] The content of the polymerization inhibitor relative to the total amount of components (A) and (B) per 100 parts by mass can be 0.01 to 10 parts by mass, 0.05 to 5 parts by mass, or 0.10 to 2 parts by mass.

[0080] (sensitizer) From the viewpoint of maintaining residual film rate under a wide range of exposure levels and good resolution, the photosensitive resin composition of the present invention may further contain a sensitizer.

[0081] Examples of sensitizing ingredients include Mischel ketone, benzoin, 2-methyl benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, 2-tert-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, anthraquinone, methylanthraquinone, 4,4'-bis(diethylamino)benzophenone, acetophenone, benzophenone, thioxanthone, 1,5-acenaphthene, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, diacetyl benzyl ester, benzyl dimethyl ketal, and benzyl... Diethyl ketal, diphenyl disulfide, anthracene, phenanthrenequinone, riboflavin tetrabutyrate, acridine orange, erythrosine, phenanthrenequinone, 2-isopropylthioxanthone, 2,6-bis(p-diethylaminobenzyl)-4-methyl-4-azacyclohexanone, 6-bis(p-dimethylaminobenzyl)-cyclopentanone, 2,6-bis(p-diethylaminobenzyl)-4-phenylcyclohexanone, aminostyrene ketone, 3-ketocoumarin compounds, dicoumarin compounds, N-phenylglycine, N-phenyldiethanolamine, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, etc. Sensitizers can be used alone or in combination of two or more.

[0082] When the sensitizer is present, its amount is preferably 0.1 to 2.0 parts by mass relative to 100 parts by mass of component (A), more preferably 0.2 to 1.5 parts by mass.

[0083] (solvent) The photosensitive resin composition described in this embodiment, by containing a solvent for dissolving / dispersing the components, can be easily coated onto a substrate to form a coating film of uniform thickness. One solvent may be used alone, or two or more solvents may be used in combination.

[0084] Examples of solvents include ketones such as methyl ethyl ketone, cyclohexanone, and cyclopentanone; aromatic hydrocarbons such as toluene, xylene, tetramethylbenzene, and 1,2,4-trimethylbenzene; glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, and γ-butyrolactone; and nitrogen-containing compounds such as mesitylene, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide.

[0085] There is no particular limitation on the amount of solvent to be prepared, and it can be 5-60% by mass, 10-50% by mass, or 15-40% by mass of the solid component in the photosensitive resin composition.

[0086] There are no particular limitations on the preparation methods or conditions of the photosensitive resin composition. For example, one method can be to use a mixer or similar equipment to thoroughly and uniformly stir and mix the main components in a specified amount, and then use a mixing roller, extruder, kneader, roller, or extruder to knead the mixture. There are no particular limitations on the kneading method.

[0087] The relative permittivity of the cured photosensitive resin composition according to this embodiment at 10 GHz can be 2.80 or less, 2.75 or less, or 2.70 or less. The dielectric loss tangent of the cured photosensitive resin composition at 10 GHz can be 0.0060 or less, 0.0050 or less, 0.0045 or less, or 0.0040 or less. The relative permittivity and dielectric loss tangent can be measured using the cured film of the photosensitive resin composition and by the method described in the examples.

[0088] The photosensitive resin composition according to this embodiment can form fine patterns. The photosensitive resin composition according to this embodiment can form an insulating film exhibiting low dielectric properties and excellent insulation reliability. Semiconductor devices having an interlayer insulating layer formed from a cured product of the above-described photosensitive resin composition, and electronic devices containing such semiconductor devices, can be manufactured. The semiconductor device, by having a rewiring layer containing a cured product of the photosensitive resin composition according to this embodiment, can improve high-frequency characteristics. The semiconductor device can be, for example, a memory, a package, etc., having a multilayer wiring structure, a rewiring structure, etc. Examples of electronic devices include mobile phones, smartphones, tablet terminals, personal computers, and hard disk drives. By having a patterned cured film formed from the photosensitive resin composition of this embodiment, semiconductor devices and electronic devices with excellent reliability can be provided.

[0089] Example The present invention will be specifically described below through embodiments, but the present invention is not limited thereto.

[0090] Synthesis of Maleimide Resin (Example 1) 9,9-bis(3,4-dicarboxyphenyl)fluorene dihydric anhydride (manufactured by JFE Chemical Corporation, product name "BPAF"), 1,2,4-trimethylbenzene (manufactured by TOYOBO CO., LTD.), Solmix A-11 (product name, manufactured by Nippon Alcohol Hanbai Co., Ltd., an alcohol solvent with ethanol as the main solvent) and γ-butyrolactone (manufactured by FUJIFILM Wako Pure Chemical Corporation) were added to a 1L flask equipped with a cooler, nitrogen inlet pipe, thermocouple, stirrer, and vacuum pump. After addition, the temperature was raised to 80°C and maintained for 0.5 hours, and dimerized diamine (DDA) (product name "PRIAMINE1075", manufactured by Croda Japan KK) was added dropwise. After the addition, norbornene diamine (NBDA) (manufactured by MITSUI FINECHEMICALS,INC Co., Ltd.) was added dropwise. Then, the mixture was kept at 80°C for approximately 0.25 hours. After this period, an aqueous solution of methanesulfonic acid (manufactured by BASF, product name "Lutropur MSA") was added. The temperature was then raised to 160°C. After this temperature increase, the pressure was reduced from atmospheric pressure to a pressure of 0.03 MPa, and a dehydration and ring-closure reaction was carried out at 160°C for 2 hours under reduced pressure to remove water and alcohol from the reaction solution, yielding the intermediate polyimide resin (imidization process). Next, the reaction vessel was set to atmospheric pressure, and the obtained polyimide resin was cooled to 130°C. Maleic anhydride (manufactured by FUSO CHEMICAL CO., LTD.) was added, and the temperature was raised to 160°C. A dehydration and ring-closure reaction was carried out at 160°C for 4 hours under a pressure of 0.03 MPa, removing water from the reaction solution, yielding the maleimide resin (maleimidization process). The proportions of each component (unit: parts by mass) are shown in Table 1. In Table 1, the amounts of non-volatile components other than organic solvents are indicated.

[0091] The obtained maleimide resin was added to a separatory funnel, along with 500 parts by mass of pure water. The funnel was shaken to mix, and the mixture was allowed to stand. After standing, the aqueous and organic layers separated, and only the organic layer was recovered. The recovered organic layer was placed in a 0.3 L glass container equipped with a cooler, nitrogen inlet tube, thermocouple, stirrer, and vacuum pump. The mixture was heated to 88–93 °C to remove water, then heated to 100 °C. The solvent was partially removed for 0.5 hours under a pressure reduction of 0.1 MPa from atmospheric pressure, yielding a solution of maleimide resin (A-1) as component (A) (40% by mass of non-volatile components). IR spectroscopy of the obtained maleimide resin (A-1) confirmed the formation of maleimide resin. The IR spectrum of maleimide resin (A-1) is shown below. Figure 1The IR spectroscopy measurements were performed as follows: the resin solids obtained by drying a solution of maleimide resin at 130°C for 30 minutes were placed in an FT-IR measuring apparatus (manufactured by Bruker, product name "AlphaII Platinum-ATR") and measured.

[0092] (Example 2) Instead of γ-butyrolactone, N-ethyl-2-pyrrolidone (NEP) was used, and the proportions of each component were changed to those shown in Table 1. Otherwise, a solution of component (A), namely maleimide resin (A-2) (40% by mass of non-volatile components), was obtained in the same manner as in Example 1. The obtained maleimide resin (A-2) was subjected to IR measurement using the same method as in Example 1, confirming the formation of maleimide resin. The IR spectrum of maleimide resin (A-2) is shown below. Figure 2 .

[0093] (Example 3) Tris(2-aminoethyl)amine (TAEA) was used as the amine in conjunction with norbornene diamine (NBDA), and the amounts of each component were changed to those shown in Table 1. Otherwise, a solution of component (A), namely maleimide resin (A-3) (40% by mass of non-volatile components), was obtained in the same manner as in Example 1. The obtained maleimide resin (A-3) was subjected to IR determination using the same method as in Example 1, confirming the formation of maleimide resin.

[0094] (Comparative Example 1) γ-Butyrolactone was not used as the organic solvent, and the amounts of each component were changed to those shown in Table 1. Otherwise, a solution of component (A), namely maleimide resin (A-4) (40% by mass of non-volatile components), was obtained in the same manner as in Example 1. The obtained maleimide resin (A-4) was subjected to IR measurement using the same method as in Example 1, confirming the formation of maleimide resin.

[0095] (Comparative Example 2) γ-Butyrolactone was not used as the organic solvent, and the amounts of each component were changed to those shown in Table 1. Otherwise, a solution of component (A), namely maleimide resin (A-5) (40% by mass of non-volatile components), was obtained in the same manner as in Example 3. The obtained maleimide resin (A-5) was subjected to IR measurement using the same method as in Example 1, confirming the formation of maleimide resin.

[0096] <Determination of Amine Value> The maleimide resin obtained in the examples and comparative examples was dissolved in a solvent (a mixture of toluene and isopropanol (IPA) in a volume ratio of 2:1) to a concentration of 11% by mass, and a sample for amine value determination was prepared. The obtained sample was placed on an automatic potentiometric titration apparatus (manufactured by Kyoto Electronics Manufacturing Co., Ltd., product name "AT-710") and titrated with 0.05 mol / L hydrochloric acid. The titration amount was determined from the titration curve, and the amine value was calculated using the following formula. The results are shown in Table 1.

[0097] Amine value (mgKOH / g) = 0.05 × f × V × 56.11 × 1000 / W f: Factor for hydrochloric acid V: Titration volume (L) W: Solid component of maleimide resin (2.5g) <Determination of weight-average molecular weight (Mw)> The weight-average molecular weight (Mw) of the maleimide resins obtained in the examples and comparative examples was determined by GPC (gel permeation chromatography). 50 μL of sample was injected into columns heated to 30°C (GL-R420 × 1 column, GL-R430 × 1 column, and GL-R440 × 1 column (all manufactured by Hitachi High-Tech Fielding Corporation)). The sample was prepared by dissolving the maleimide resin in tetrahydrofuran (THF) to a concentration of 3% by mass. The determination was performed using THF as the developing solvent at a flow rate of 1.6 mL / min. Furthermore, an L-3350 RI detector (manufactured by Hitachi, Ltd.) was used as the detector. Mw was calculated based on the dissolution time using a molecular weight / dissolution time curve prepared using standard polystyrene (manufactured by TOSOH CORPORATION). The results are presented as initial Mw in Table 1.

[0098] <Preparation of Resin Compositions> To 85 parts by weight of the maleimide resin solution (40% by weight of non-volatile component) obtained in the Examples and Comparative Examples, 5 parts by weight of A-9300 (crosslinking agent), 10 parts by weight of TAIC (crosslinking agent), 3 parts by weight of OXE01 (photoinitiator), 2 parts by weight of OXE02 (photoinitiator), 1.7 parts by weight of PERBUTYL P (thermal initiator), 1.7 parts by weight of KBM-503 (silane coupling agent), 1.7 parts by weight of BT-120G (rust inhibitor), and 0.25 parts by weight of TEMPOL (polymerization inhibitor) were added, and cyclopentanone was added to bring the non-volatile component to 40% by weight, thus obtaining a resin composition. Details of each component are as follows.

[0099] A-9300: Tris-(2-Acryloyloxyethyl)isocyanurate (manufactured by SHIN-NAKAMURA CHEMICAL CO,LTD., product name "A-9300", number of acryloyl groups: 3) TAIC: Triallyl isocyanurate (manufactured by Mitsubishi Chemical Corporation, product name "TAIC", number of allyl groups: 3) OXE01: Oxime ester-based photopolymerization initiator (manufactured by BASF Japan Ltd., product name "Irgacure OXE01") OXE02: Oxime ester-based photopolymerization initiator (manufactured by BASF Japan Ltd., product name "Irgacure OXE02") PERBUTYL P: α,α'-bis(tert-butylperoxy)diisopropylbenzene (manufactured by Nippon Oil Corporation, product name "PERBUTYL P") KBM-503: 3-Methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-503") BT-120G: 1,2,3-benzotriazole (manufactured by Johoku Chemical Co., Ltd., product name "BT-120G") TEMPOL: 4-Hydroxy-2,2,6,6-Tetramethylpiperidine-1-Oxy radical (manufactured by Tokyo Chemical Industry Co., Ltd.) <Viscosity Measurement> The viscosity of the resin composition prepared above was measured by adding 1 mL to the sample holder of an E-type viscometer (manufactured by TOYO SEIKI SEIZO KABUSHIKI KAISHA, product name "RE-85") adjusted to 25℃±0.2℃. The results are shown in Table 1 as the initial viscosity.

[0100] <Evaluation of preservation stability> The resin composition prepared above was stored in the dark at 25°C. The molecular weight (Mw) of the maleimide resin and the viscosity of the resin composition were measured after 360 hours and 720 hours of storage, using the same method as described above. Furthermore, based on the obtained results, the storage stability was evaluated according to the following criteria. The results are shown in Table 1.

[0101] (Judgment criteria) A: In the changes relative to the initial 720-hour storage values, Mw increased by less than 1000 and viscosity increased by less than 25 mPa·s.

[0102] B: In changes that do not correspond to judgment A and are relative to the initial 720-hour storage value, Mw increases by less than 1500 or viscosity increases by less than 40 mPa·s.

[0103] C: In the changes relative to the initial 720-hour storage values, Mw increased by more than 1500 and viscosity increased by more than 40 mPa·s.

[0104] [Table 1]

Claims

1. A method for manufacturing a maleimide resin, wherein the maleimide resin is a maleimide resin obtained by reacting tetracarboxylic dianhydride (a1), an amine (a2), and maleic anhydride (a3), and the manufacturing method comprises the following steps: In the presence of an organic solvent, the amine (a2) is added to the tetracarboxylic dianhydride (a1) to obtain a polyimide resin; and Maleic anhydride (a3) ​​is added to the polyimide resin to obtain a maleimide resin. The organic solvent comprises at least one of γ-butyrolactone and N-ethyl-2-pyrrolidone. The amine (a2) includes dimerized diamine and a second amine other than dimerized diamine.

2. The method for manufacturing maleimide resin according to claim 1, wherein, At least one of the tetracarboxylic dianhydride (a1) and the amine (a2) comprises a compound having a fluorene skeleton.

3. The method for manufacturing maleimide resin according to claim 1, wherein, The tetracarboxylic dianhydride (a1) comprises at least one of 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 9,9-bis(3,4-dicarboxyphenyl)fluorenic anhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorenic anhydride, and 3,3',4,4'-biphenyltetracarboxylic dianhydride.

4. The method for manufacturing maleimide resin according to claim 1, wherein, The second amine contains at least one of norbornene diamine, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, and 9,9-bis(4-aminophenyl)fluorene.

5. The method for manufacturing maleimide resin according to claim 1, wherein, The dimer diamine contains at least one of the compounds represented by general formula (1) and general formula (2). In equations (1) and (2), m, n, p and q represent integers of 1 or more selected in the manner of m+n=6~17 and p+q=8~19 respectively. The bond represented by the dashed line refers to a carbon-carbon single bond or a carbon-carbon double bond. In the case where the bond represented by the dashed line is a carbon-carbon double bond, equations (1) and (2) have the following structure: the structure obtained by subtracting 1 from the number of hydrogen atoms bonded to each carbon atom constituting the carbon-carbon double bond as shown in equations (1) and (2).

6. The method for manufacturing maleimide resin according to claim 1, wherein, It is prepared by reacting the tetracarboxylic acid dianhydride (a1) at a rate of 0.30 to 1.00 moles relative to 1.00 mole of the amine (a2).

7. The method for manufacturing maleimide resin according to claim 1, wherein, The organic solvent further comprises aromatic hydrocarbons with a boiling point above 150°C.

8. The method for manufacturing maleimide resin according to claim 1, wherein, The organic solvent further comprises alcohols with a boiling point below 100°C.

9. The method for manufacturing maleimide resin according to claim 1, wherein, Based on the total amount of organic solvent, the content of γ-butyrolactone and N-ethyl-2-pyrrolidone in the organic solvent is 5 to 40% by mass.

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