Curable resin compositions, semiconductor encapsulants, adhesives, adhesive films, prepregs, interlayer insulating materials, and printed circuit boards.

Abstract

To provide a resin composition excellent in workability and flowability because of a low viscosity of a maleimide compound contained as a base resin in the composition, where the composition is capable of forming a cured product exhibiting excellent dielectric properties even at high frequencies, without significant change in the dielectric properties even after being left at high temperature for a long period, and being less susceptible to moisture absorption.SOLUTION: The curable resin composition contains: (A) a maleimide compound represented by the general formula (1) in the figure (where A represents a dimer acid- and trimer acid-derived hydrocarbon group); and (B) a catalyst. Regarding A in the formula (1), the dimer acid-derived hydrocarbon groups account for 95 mass% or more of the dimer acid- and trimer acid-derived hydrocarbon groups, and A is a hydrogenated group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable resin composition, a semiconductor encapsulant, an adhesive, an adhesive film, a prepreg, an interlayer insulating material and a printed wiring board. [Background Art]

[0002] In recent years, the next-generation communication system 5G, which operates in the millimeter wave range of 26 GHz to 80 GHz, has become widespread, and the development of the next-next-generation communication system 6G has also commenced, with attempts to achieve communication with higher speed, larger capacity and lower latency than ever before. To realize these communication systems, materials for high frequency bands of 3 GHz to 80 GHz are required, and reduction of transmission loss is essential as a noise countermeasure. Transmission loss is the sum of conductor loss and dielectric loss. To reduce conductor loss, it is necessary to lower the surface roughness of the metal foil used. On the other hand, since dielectric loss is proportional to the product of the square root of the relative dielectric constant and the dielectric loss tangent, development of an insulating material with excellent dielectric properties (low relative dielectric constant and low dielectric loss tangent) is required for use as an insulating material. Among these, such insulating materials with excellent dielectric properties are in demand for substrate applications. In rigid substrates, reactive polyphenylene ether resin (PPE) is used, while in flexible printed circuit boards (FPC), products such as liquid crystal polymer (LCP) and modified polyimide (MPI) with improved properties have come into use.

[0003] In contrast, the use of a maleimide compound having substantially a dimer diamine skeleton (a skeleton derived from dimer acid) (special maleimide compound) as the main resin for substrates has been reported (Patent Documents 1 to 4). Contrary to the properties of common maleimide resins, the special maleimide compound has a low glass transition temperature (Tg) and a high coefficient of thermal expansion (CTE), but it also has many advantages: it exhibits extremely excellent dielectric properties, has flexible characteristics, excellent adhesive strength to metals and the like, and as a thermosetting resin, it has the potential to be formed into (high) multilayers. Accordingly, research and development have been conducted on such compounds over a wide range. However, the special maleimide compound has mainly been used alone. Furthermore, as mentioned above, dielectric loss is proportional to the ratio of the square root of the relative permittivity to the dielectric loss tangent. Therefore, it is even more important to lower the dielectric loss tangent.

[0004] On the other hand, it has been reported that resin materials using maleimide compounds having a trimertriamine skeleton (a skeleton derived from trimer acid) as the main resin for substrates exhibit excellent heat resistance, mechanical strength, dielectric properties, etc. (Patent Documents 5 and 6). Generally, dimer acids and trimer acids are mixtures and are often collectively referred to as dimer acids. Similarly, dimeramines and trimertriamines derived from dimer acids and trimer acids are collectively referred to as dimeramines, and it is well known that even in commercially available compounds called dimeramines, the ratio of dimeramines to trimertriamines varies depending on the product (Patent Document 7, Non-Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-131243 [Patent Document 2] Japanese Patent Publication No. 2016-131244 [Patent Document 3] International Publication No. 2016 / 114287 [Patent Document 4] Japanese Patent Publication No. 2018-201024 [Patent Document 5] Japanese Patent Publication No. 2019-182932 [Patent Document 6] International Publication No. 2020 / 45408 [Patent Document 7] Japanese Patent Publication No. 2017-186551 [Non-patent literature]

[0006] [Non-Patent Document 1] Journal of Synthetic Organic Chemistry, 1967, 25(2), 180-183 [Overview of the project] [Problems that the invention aims to solve]

[0007] Against this backdrop, we synthesized and investigated maleimide compounds having structures derived from these trimertriamine skeletons. We found that these maleimide compounds have high viscosity, posing challenges to the workability and flowability of compositions incorporating them. Furthermore, their cured products exhibit high relative permittivity and dielectric loss tangent at high frequencies, and are significantly affected by moisture absorption. Accordingly, the present invention aims to provide a curable resin composition in which the maleimide compound that serves as the base resin in the composition has low viscosity, resulting in excellent workability and flowability, exhibits excellent dielectric properties even at high frequencies, shows little change in dielectric properties after being left at high temperatures for a long time, and is less affected by moisture absorption, and further aims to provide semiconductor encapsulants, adhesives, adhesive films, prepregs, interlayer insulating materials, and printed circuit boards containing the same. [Means for solving the problem]

[0008] The inventors of this invention conducted extensive research to solve the above problems and, as a result, discovered that the following resin composition can achieve the above objectives, thus completing the present invention.

[0009] In other words, the present invention provides the following curable resin composition. [1] (A) Maleimide compounds represented by the following general formula (1) [ka] (In formula (1), A represents a hydrocarbon group derived from dimer acid and trimer acid.) and (B) Catalyst A curable resin composition containing, A in formula (1) is a curable resin composition in which the proportion of hydrocarbon groups derived from dimer acid among the hydrocarbon groups derived from dimer acid and trimer acid is 95% by mass or more, and the group is hydrogenated. [2] The curable resin composition according to [1], wherein the viscosity of the maleimide compound as component (A), measured in accordance with the method described in JIS Z8803:2011 at a measurement temperature of 25°C using a Brookfield rotational viscometer under the condition of a spindle rotation speed of 5 rpm, is 7.0 Pa·s or less. [3] The curable resin composition according to [1] or [2], wherein the number average molecular weight of the maleimide compound as component (A) is 1150 or less. [4] The curable resin composition according to any one of [1] to [3], wherein the catalyst as component (B) is at least one selected from the group consisting of organic peroxides, anionic polymerization initiators and photocuring initiators. [5] A semiconductor encapsulating material comprising the curable resin composition according to any one of [1] to [4]. [6] An adhesive comprising the curable resin composition according to any one of [1] to [4]. [7] An adhesive film comprising the curable resin composition according to any one of [1] to [4]. [8] A prepreg comprising the curable resin composition according to any one of [1] to [4] and a fiber base material. [9] An interlayer insulating material comprising the curable resin composition according to any one of [1] to [4].

[10] A printed wiring board having a cured product of the curable resin composition according to any one of [1] to [4]. Effects of the Invention

[0010] The curable resin composition of the present invention is excellent in workability and flow property because the maleimide compound serving as the base resin in the composition has low viscosity. After curing, the curable resin composition has excellent dielectric properties even at high frequencies and even after being placed under high temperature for a long time, and is less affected by moisture absorption. Therefore, the resin composition is useful for semiconductor encapsulating materials, adhesives, adhesive films, prepregs, interlayer insulating materials and printed wiring boards. Brief Description of Drawings

[0011] [Figure 1] This is a cross-section view showing an example of the prepreg of the present invention. [Figure 2] This is a cross-section view showing an example of the laminate of the present invention. [Figure 3] This is a cross-section view showing an example of a printed circuit board according to the present invention. [Modes for carrying out the invention]

[0012] The present invention will be described in more detail below.

[0013] (A) Maleimide compounds represented by the following general formula (1) Component (A) is a maleimide compound represented by the following general formula (1). [ka] In formula (1), A represents a hydrocarbon group derived from dimer acid and trimer acid.

[0014] In formula (1), A represents a hydrocarbon group derived from dimer acid that accounts for 95% by mass or more of the total hydrocarbon groups derived from dimer acid and trimer acid. Hereafter, this proportion of hydrocarbon groups derived from dimer acid among the total hydrocarbon groups derived from dimer acid and trimer acid may be simply referred to as the "dimer ratio" or as dimer:trimer. When the dimer ratio is 95% by mass or more, the viscosity of the maleimide compound of component (A) is low, the compound itself has excellent handling properties, and when formed into a composition, it has advantages such as high moldability. The dimer ratio is 95% by mass or more, preferably 96% by mass or more, more preferably 97% by mass or more, even more preferably 98% by mass or more, and particularly preferably 99% by mass or more. Furthermore, A in formula (1) is a hydrogenated group. That is, as described below, the group corresponding to group A in the amine compound that is the raw material for component (A) may contain a double bond, but an amine compound in which the double bond has been reduced by hydrogenation is used as the raw material. By reducing the double bond in group A, oxidation of the double bond is suppressed, and deterioration due to heat and the resulting deterioration of dielectric properties can be prevented.

[0015] In this specification, the dimer ratio is a value calculated from the peak area ratio obtained by gas chromatography (GC) measurement performed under the following measurement conditions. Measurement conditions: Equipment: GC-2014 (manufactured by Shimadzu Corporation) Column: DB-5 30m × 0.25mm × 0.25μm Evaporation chamber temperature: 280℃ Temperature: 50℃ → 10℃ / min → 300℃, held for 20 minutes Column flow rate: 1.00 mL / min Purge flow rate: 3.00 mL / min

[0016] As mentioned above, dimer acids and trimer acids are generally mixtures and are often collectively referred to as dimer acids. Similarly, dimeramines and trimertriamines derived from dimer acids and trimer acids are collectively referred to as dimeramines, and it is well known that the ratio of dimeramines to trimertriamines varies depending on the product, even in commercially available compounds called dimeramines.

[0017] In this context, dimer acid refers to a liquid dibasic acid whose main component is a 36-carbon dicarboxylic acid, produced by the dimerization of 18-carbon unsaturated fatty acids derived from natural materials such as plant oils. Dimer acid does not have a single structure but rather multiple structures, and several isomers exist. Representative dimer acids are classified as linear (a), monocyclic (b), aromatic cyclic (c), and polycyclic (d).

[0018] [ka]

[0019] Furthermore, trimer acid is a by-product of dimer acid production, and like dimer acid, trimer acid does not have a single structure but has multiple structures and several isomers exist. A typical structure is shown in formula (e) below. [ka] (In formula (e), R represents an ethylene group or an ethenylene group.)

[0020] The component (A) used in the present invention can be produced using a mixture of dimeramine derived from dimer acid and trimertriamine derived from trimer acid (hereinafter referred to as a mixture of dimeramine and trimertriamine) as a raw material. Dimeramine derived from dimer acid has a structure in which two carboxyl groups of dimer acid are each replaced with primary aminomethyl groups, and similarly, trimertriamine derived from trimer acid has a structure in which three carboxyl groups of trimer acid are each replaced with primary aminomethyl groups. Therefore, when A in formula (1) represents a hydrocarbon group derived from dimer acid and trimer acid, it means that group A originates from a mixture of dimeramine derived from dimer acid and trimertriamine derived from trimer acid.

[0021] A specific method for producing component (A) used in the present invention is, for example, a method of reacting a mixture of dimer amine and trimer triamine with maleic anhydride. This reaction can be carried out in accordance with known methods for synthesizing polyimides, which involve synthesizing amic acid from a diamine and a carboxylic acid anhydride and then dehydrating the amic acid. Specifically, the reaction to synthesize amic acid generally proceeds in an organic solvent (e.g., a nonpolar solvent or a high-boiling point aprotic polar solvent) at room temperature (25°C) to 100°C. The subsequent ring-closing dehydration reaction of the amic acid proceeds under conditions of 90-120°C, while removing the water produced as a by-product by the condensation reaction. To accelerate the ring-closing dehydration reaction, an organic solvent (e.g., a nonpolar solvent, a high-boiling point aprotic polar solvent, etc.) or an acid catalyst may be added. Examples of organic solvents include toluene, xylene, anisole, biphenyl, naphthalene, N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). These may be used individually or in combination of two or more. Examples of acid catalysts include sulfuric acid, methanesulfonic acid, and trifluoromethanesulfonic acid. These may be used individually or in combination of two or more. The molar ratio of maleic anhydride to the mixture of dimer amine and trimer triamine is preferably maleic anhydride / mixture of dimer amine and trimer triamine = 6.0 to 2.2 / 1.0.

[0022] In the above reaction, the ratio of dimeramine and trimertriamine in the mixture of raw materials and whether or not hydrogenation is performed are directly reflected in the resulting maleimide compound. Therefore, from the viewpoint of productivity, it is preferable to use a mixture of dimeramine and trimertriamine as raw materials in which the dimer content is 95% by mass or more and which has been hydrogenated. The following commercially available products are examples of such a mixture of dimeramine and trimertriamine. Versamin 552 (manufactured by Cognics Japan Co., Ltd.), dimer:trimmer ≈ 95:5, hydrogenated. Priamine-1075 (manufactured by Croda Japan Co., Ltd.), dimer:trimmer = 98:2, hydrogenated. The above-mentioned commercially available products or commercially available mixtures of dimeramine and trimertriamine other than those mentioned above may be used after increasing the dimer ratio by purification methods such as thin-film distillation, or the dimer ratio may be adjusted by combining mixtures of multiple types of dimeramine and trimertriamine with different dimer ratios. In addition, commercially available mixtures of dimeramine and trimertriamine that have not been hydrogenated may be used after being hydrogenated using a catalyst such as Raney nickel.

[0023] Furthermore, for ease of handling at room temperature, the maleimide compound of component (A) preferably has a viscosity of 7.0 Pa·s or less, more preferably 6.0 Pa·s or less, as measured by the following method. A viscosity of 7.0 Pa·s or less is preferable because it improves moldability, wettability to the substrate, and adhesion. Measurement conditions: In accordance with the method described in JIS Z8803:2011, a Brookfield type rotational viscometer was used at a measurement temperature of 25°C, with a spindle rotation speed of 5 rpm. To make the viscosity of the maleimide compound of component (A) 7.0 Pa·s or less under the above measurement conditions, the maleimide compound of formula (1) should be such that group A is hydrogenated and the dimer ratio is 95% by mass or more, but the higher the hydrogenation rate and the higher the dimer ratio, the better.

[0024] The number-average molecular weight of the maleimide compound of component (A) is preferably 1150 or less, and more preferably 1100 or less. To make the number-average molecular weight of the maleimide compound of component (A) 1150 or less, the maleimide compound of formula (1) should be such that group A is hydrogenated and the dimer ratio is 95% by mass or more, but the higher the hydrogenation rate and the higher the dimer ratio, the better. In this invention, the number-average molecular weight refers to the number-average molecular weight measured by gel permeation chromatography (GPC) with polystyrene as the standard substance, under the following conditions.

[0025] [Measurement conditions] Developing solvent: Tetrahydrofuran (THF) Flow rate: 0.35mL / min Detector: Differential refractive index detector (RI) Column: TSK Guardcolumn SuperH-L TSKgel SuperHZ4000(4.6mmI.D.×15cm×1) TSKgel SuperHZ3000(4.6mmI.D.×15cm×1) TSKgel SuperHZ2000(4.6mmI.D.×15cm×2) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 5 μL (THF solution with a concentration of 0.2% by mass)

[0026] (A) Component (A) may be used alone or in a mixture of two or more components. Furthermore, the content of component (A) in the curable resin composition of the present invention is preferably 1 to 99.9% by mass, and more preferably 3 to 99% by mass.

[0027] (B) Catalyst Component (B) used in this invention is a catalyst. The catalyst in this invention initiates or promotes the reaction of the maleimide group of component (A) and / or groups that can react with the maleimide group as described later. There are no particular restrictions on component (B) as long as it initiates or promotes the reaction of the maleimide group of component (A) and / or groups that can react with the maleimide group as described later, but at least one selected from organic peroxides, anionic polymerization initiators and photocuring initiators is preferably used.

[0028] Examples of organic peroxides include dicumyl peroxide, t-butyl peroxybenzoate, t-amyl peroxybenzoate, dibenzoyl peroxide, diuraloyl peroxide, 2,5-dimethyl-2,5-di(t-butyl peroxy)hexane, 1,1-di(t-butyl peroxy)cyclohexane, di-t-butyl peroxide, and dibenzoyl peroxide.

[0029] Examples of anionic polymerization initiators include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, and 2-phenyl-4,5-dihydroxymethylimidazole. Examples include imidazole compounds such as zole and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organophosphorus compounds such as tributylphosphine, tri(p-methylphenyl)phosphine, tri(nonylphenyl)phosphine, triphenylphosphine, triphenylphosphine oxide, triphenylphosphine-triphenylborane, and tetraphenylphosphine-tetraphenylborate; and tertiary amine compounds such as triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 1,8-diazabicyclo[5.4.0]undecene, and tris(dimethylaminomethyl)phenol.

[0030] There are no particular limitations on the photocuring initiator as long as it initiates the reaction with light, but examples include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropanone-1, 2,4-diethylthioxanthone, 2-ethylanthraquinone, and phenanthrenequinone. Aromatic ketones; benzyl derivatives such as benzyldimethyl ketal; 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, 2,4-di(p-methoxyphenyl 2,4,5-triarylimidazole dimers such as (2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer and 2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer; acridine derivatives such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; bisacyls such as bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. Examples include phosphine oxides; alkylphenone compounds such as 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone; acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; and benzophenone compounds.

[0031] The amount of component (B) is preferably 0.1 to 5.0 parts by mass, more preferably 0.2 to 4.5 parts by mass, and even more preferably 0.5 to 4.0 parts by mass, per 100 parts by mass of component (A). Furthermore, if the composition of the present invention contains a curable resin having a reactive group that can react with a maleimide group, other than component (A) described later, the total of component (A) and the curable resin having a reactive group that can react with a maleimide group is considered as the curable resin component, and the amount of component (B) blended is preferably 0.1 to 7.0 parts by mass, more preferably 0.2 to 6.0 parts by mass, and even more preferably 0.5 to 5.0 parts by mass, per 100 parts by mass of the curable resin component. If the amount of component (B) per 100 parts by mass of component (A) is less than 0.1 parts by mass, the hardening process may be slowed down, and if it exceeds 5.0 parts by mass, the product may lack storage stability. (B) Component (B) may be used alone or in a mixture of two or more components.

[0032] Other additives The curable resin composition of the present invention may further contain various additives as needed, provided that the effects of the present invention are not impaired. Examples of other additives are listed below.

[0033] Curable resin having a reactive group that can react with a maleimide group. In the present invention, a curable resin having a reactive group that can react with a maleimide group may be added. The curable resin is not limited to any particular type and can include, for example, epoxy resins, phenolic resins, melamine resins, silicone resins, cyclic imide resins including maleimide compounds other than component (A), urea resins, thermosetting polyimide resins, modified polyphenylene ether resins, (meth)acrylic resins, epoxy-silicone hybrid resins, and various other resins other than component (A). Furthermore, reactive groups that can react with the maleimide group include epoxy groups, maleimide groups, hydroxyl groups, acid anhydride groups, alkenyl groups such as allyl and vinyl groups, (meth)acrylic groups, and thiol groups.

[0034] From the viewpoint of reactivity, the reactive group of the curable resin is preferably selected from epoxy groups, maleimide groups, hydroxyl groups, and alkenyl groups, and from the viewpoint of dielectric properties, alkenyl groups or (meth)acrylic groups are more preferred. However, the amount of curable resin having a reactive group that can react with the maleimide group is 0 to 80% by mass of the total curable resin components.

[0035] inorganic filler In the present invention, inorganic fillers may be added as needed. Inorganic fillers are added to increase the strength and rigidity of the cured product of the curable resin composition of the present invention, or to adjust the coefficient of thermal expansion and the dimensional stability of the cured product. As inorganic fillers, those that are normally added to epoxy resin compositions and silicone resin compositions can be used. Examples include silicas such as spherical silica, fused silica and crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, barium sulfate, talc, clay, aluminum hydroxide, magnesium hydroxide, calcium carbonate, glass fibers and glass particles. Furthermore, fluororesins, coating fillers, and / or hollow particles may be used to improve dielectric properties, and conductive fillers such as metal particles, metal-coated inorganic particles, carbon fibers, and carbon nanotubes may be added for purposes such as imparting conductivity. One type of inorganic filler may be used alone, or two or more types may be used in combination. The amount of inorganic filler added may be 0 to 300 parts by mass per 100 parts by mass of component (A), and 30 to 300 parts by mass is preferred.

[0036] The average particle size and shape of the inorganic filler are not particularly limited, but when forming films or substrates, spherical silica with an average particle size of 0.5 to 5 μm is particularly preferred. The average particle size is determined by the mass-mean value D of the particle size distribution measurement by laser diffraction. 50 This is the value obtained as (or median diameter).

[0037] Furthermore, to improve the properties of the inorganic filler, it is preferable that the surface is treated with a silane coupling agent having an organic group that can react with the maleimide group. Examples of such silane coupling agents include epoxy group-containing alkoxysilanes, amino group-containing alkoxysilanes, (meth)acrylic group-containing alkoxysilanes, and alkenyl group-containing alkoxysilanes. As the silane coupling agent, (meth)acrylic group and / or amino group-containing alkoxysilanes are preferably used, specifically, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and the like.

[0038] others In addition to the above, non-functional silicone oil, reactive diluents, thermoplastic resins, thermoplastic elastomers, organic synthetic rubbers, photosensitizers, light stabilizers, polymerization inhibitors, antioxidants, flame retardants, pigments, dyes, adhesive aids, ion trapping materials, etc. may also be included. Furthermore, silane coupling agents such as epoxy group-containing alkoxysilanes, amino group-containing alkoxysilanes, (meth)acrylic group-containing alkoxysilanes, and alkenyl group-containing alkoxysilanes, which are used to surface-treat the inorganic fillers described above, may also be separately incorporated into the curable resin composition of the present invention, and specific examples are the same as those described above.

[0039] The curable resin composition of the present invention can also be dissolved in an organic solvent and treated as a varnish. By varnishing the composition, it becomes easier to form a film, and it also becomes easier to apply to and impregnate fibrous substrates such as glass cloth made of E glass, low dielectric glass, or quartz glass. The organic solvent can be used without limitation as long as it dissolves the curable resin having reactive groups that can react with components (A), (B), and other additives such as maleimide groups. Examples include anisole, tetralin, mesitylene, xylene, toluene, tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and acetonitrile. These may be used individually or in combination of two or more.

[0040] [Manufacturing method] A method for producing the curable resin composition of the present invention includes mixing component (A) and component (B), as well as other additives as needed, using, for example, a planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.) or a stirrer THINKY CONDITIONING MIXER (manufactured by Thinky Co., Ltd.).

[0041] [Uncured resin film / Cured resin film] The curable resin composition of the present invention can be obtained by coating the aforementioned varnish onto a substrate and volatilizing the organic solvent to produce an uncured resin sheet or uncured resin film, or by further curing it to produce a cured resin sheet or cured resin film. The following are examples of methods for producing sheets and films, but are not limited thereto.

[0042] For example, after applying a curable resin composition (varnish) dissolved in an organic solvent to a substrate, the organic solvent is removed by heating at a temperature of 80°C or higher, preferably 100°C or higher, for 0.5 to 20 minutes, and then by further heating at a temperature of 130°C or higher, preferably 150°C or higher, for 0.5 to 10 hours, a resin cured film with a flat and strong surface can be formed. The temperature in the drying step to remove the organic solvent and the subsequent heat curing step may be constant, but it is preferable to gradually increase the temperature. This allows for efficient removal of the organic solvent from the composition and efficient progress of the resin curing reaction. Methods for applying varnish include spin coater, slit coater, spray, dip coater, and bar coater, but there are no particular restrictions.

[0043] A general resin substrate can be used as the base material, such as polyolefin resins like polyethylene (PE) resin, polypropylene (PP) resin, and polystyrene (PS) resin, and polyester resins like polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, and polycarbonate (PC) resin. The surface of the base material may be treated with a release agent. The thickness of the coating layer is not particularly limited, but the thickness after solvent removal is in the range of 1 to 100 μm, preferably 3 to 80 μm. Furthermore, a cover film may be used on top of the coating layer.

[0044] Alternatively, the components may be pre-mixed and then extruded into a sheet or film using a melt kneader to produce an uncured resin film or a cured resin film.

[0045] The cured film obtained by curing the curable resin composition of the present invention exhibits excellent heat resistance, mechanical properties, electrical properties, adhesion to substrates, and solvent resistance, as well as a low dielectric constant. Therefore, it can be applied to semiconductor devices, specifically passivation films and protective films on the surface of semiconductor elements, junction protective films for junctions of diodes and transistors, alpha-ray shielding films for VLSIs, interlayer insulating films, ion implantation masks, and conformal coatings for printed circuit boards, alignment films for liquid crystal surface elements, protective films for glass fibers, and surface protective films for solar cells. Furthermore, it can be applied to a wide range of paste compositions, such as printing paste compositions containing inorganic fillers and conductive paste compositions containing conductive fillers. Among these, adhesive applications are particularly preferred.

[0046] Furthermore, because it can be formed into a film or sheet in its uncured state, possesses self-adhesive properties, and has excellent dielectric properties, it can be suitably used as a bonding film for flexible printed circuit boards (FPCs) and as an interlayer insulating material for rigid substrates. The cured resin film can also be used as a coverlay film.

[0047] Alternatively, a varnished, curable resin composition can be impregnated into a fibrous substrate such as glass cloth made of E-glass, low-dielectric glass, or quartz glass, and then the organic solvent is removed to create a semi-cured state for use as a prepreg. Furthermore, by laminating this prepreg or copper foil, laminates and printed circuit boards, including those with multiple layers, can be manufactured.

[0048] [Prepreg] Figure 1 shows a schematic end view of a prepreg according to one embodiment of the present invention. The prepreg 1 comprises a curable resin composition 2 and a fibrous substrate 3. The curable resin composition 2 is the curable resin composition or a semi-cured product of the resin composition. A semi-cured product is a resin composition that has partially cured to the point where it can be further cured. In other words, a semi-cured product is a resin composition that has been partially cured, or what is known as the B-stage. On the other hand, the uncured state is sometimes called the A-stage. In other words, the curable resin composition 2 may be the curable resin composition in the A-stage state, or it may be the curable resin composition in the B-stage state.

[0049] As mentioned above, the fiber base material 3 can be E glass, low dielectric glass, quartz glass, and even S glass and T glass. While the type of glass used is not limited, quartz glass cloth with low dielectric properties is preferred from the viewpoint of making the most of the properties of the curable resin composition. The thickness of the fiber base material that is generally used is, for example, 0.01 mm or more and 0.3 mm or less.

[0050] When manufacturing the prepreg 1, it is preferable that the curable resin composition 2 be a varnish-like resin varnish prepared for impregnation into the fibrous substrate 3, which is the base material for forming the prepreg. Such a varnish-like resin composition (resin varnish) can be prepared, for example, as follows. First, each component of the resin composition that is soluble in an organic solvent is added to the organic solvent and dissolved. Heating may be used as needed during this process. Then, components that are not soluble in the organic solvent, such as inorganic fillers, are added as needed, and the mixture is dispersed using a ball mill, bead mill, planetary mixer, roll mill, etc., until a predetermined dispersion state is reached, thereby preparing a varnish-like resin composition (resin varnish). The organic solvent used here is not particularly limited as long as it does not inhibit the curing reaction. Specifically, examples include toluene, methyl ethyl ketone (MEK), xylene, and anisole.

[0051] One method for producing the prepreg 1 is to impregnate a fiber substrate 3 with a curable resin composition 2, for example, a curable resin composition 2 prepared in the form of a varnish, and then dry it. The curable resin composition 2 is impregnated into the fiber substrate 3 by immersion, coating, etc. It is possible to repeat the impregnation process multiple times as needed. In addition, it is possible to adjust to the desired composition and impregnation amount by repeating the impregnation process using multiple resin compositions with different compositions and concentrations. The fiber substrate 3 impregnated with the curable resin composition (resin varnish) 2 is heated under desired heating conditions, for example, at 80°C to 180°C for 1 minute to 20 minutes. Heating yields a prepreg 1 comprising the curable resin composition 2 in a pre-cured state (Stage A) or a semi-cured state (Stage B). Note that the heating can volatilize the organic solvent from the resin varnish, thereby reducing or removing the organic solvent.

[0052] [Laminated board] A laminate according to one embodiment of the present invention is formed by laminating an insulating layer containing a cured product of the curable resin composition or an insulating layer made of a cured product of the curable resin composition with a layer other than the insulating layer. A commonly known laminate is a metal-clad laminate, and its schematic end view is shown in Figure 2. The metal-clad laminate 11 comprises an insulating layer 12 containing or made of a cured product of the curable resin composition, and metal foil 13 on both sides of the insulating layer 12. Figure 2 shows a double-sided metal-clad laminate with metal foil 13 on both sides of the insulating layer 12, but a single-sided metal-clad laminate may also be used, with metal foil 13 on only one side of the insulating layer 12. Furthermore, the insulating layer 12 may be made of a cured product of the curable resin composition, or of a cured product of the aforementioned prepreg, or it may be made by laminating multiple cured products of the prepreg 1. The thickness of the metal foil 13 is not particularly limited and varies depending on the performance required of the final printed circuit board. The thickness of the metal foil 13 can be set appropriately according to the desired purpose, and is preferably, for example, 1 to 70 μm. Examples of the metal foil 13 include copper foil and aluminum foil, and if the metal foil is thin, it may be a carrier-equipped copper foil with a release layer and carrier to improve handling. The method for manufacturing such laminates is not particularly limited as long as it is a general method. For example, when using prepregs, one or more prepregs 1 (Figure 1) are stacked, and then metal foils 13 such as copper foil are placed on both the top and bottom surfaces or one or both surfaces, and the laminates are manufactured by heating, pressing, and molding to integrate them.

[0053] [Printed wiring board] A printed circuit board according to one embodiment of the present invention includes a cured product of the curable resin composition. As an example, Figure 3 shows a schematic end view of a printed circuit board manufactured using the laminate, particularly the metal-clad laminate shown in Figure 2. As described above, the insulating layer 12 of the metal-clad laminate used in the manufacture of the printed circuit board may be manufactured using the prepreg described above. The printed circuit board 21 can be manufactured by known methods, such as drilling, metal plating, etching of metal foil to form circuits, and multilayer bonding.

[0054] [Semiconductor encapsulant] When using the curable resin composition of the present invention as a semiconductor encapsulant, components (A) and (B), and other components as needed, are blended in a predetermined composition ratio, thoroughly and uniformly mixed using a mixer or the like, then melt-mixed using a hot roll, kneader, extruder or the like, then cooled and solidified, and finally crushed to an appropriate size. The resulting resin composition can be used as an encapsulant material.

[0055] Common molding methods for semiconductor encapsulants include transfer molding and compression molding. In transfer molding, a transfer molding machine is used, and the molding pressure is 5-20 N / mm². 2 The molding process is carried out at a molding temperature of 120-190°C for 30-500 seconds, preferably at a molding temperature of 150-185°C for 30-180 seconds. In the compression molding method, a compression molding machine is used, and the molding temperature is 120-190°C for 30-600 seconds, preferably at a molding temperature of 130-160°C for 120-300 seconds. Furthermore, in any of the molding methods, post-curing may be carried out at 150-225°C for 0.5-20 hours. [Examples]

[0056] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0057] The components used in the examples and comparative examples are shown below. In the following, the number-average molecular weight (Mn) was measured using polystyrene as the reference, under the measurement conditions described below. [Measurement conditions] Developing solvent: Tetrahydrofuran (THF) Flow rate: 0.35mL / min Detector: Differential refractive index detector (RI) Column: TSK Guardcolumn SuperH-L TSKgel SuperHZ4000(4.6mmI.D.×15cm×1) TSKgel SuperHZ3000(4.6mmI.D.×15cm×1) TSKgel SuperHZ2000(4.6mmI.D.×15cm×2) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 5 μL (THF solution with a concentration of 0.2% by mass)

[0058] Furthermore, the dimer ratio (dimer:trimer mass ratio) was calculated from the peak area ratio obtained by gas chromatography (GC) measurement under the following measurement conditions. [Measurement conditions] Equipment: GC-2014 (manufactured by Shimadzu Corporation) Column: DB-5 30m × 0.25mm × 0.25μm Evaporation chamber temperature: 280℃ Temperature: 50℃ → 10℃ / min → 300℃, held for 20 minutes Column flow rate: 1.00 mL / min Purge flow rate: 3.00 mL / min

[0059] Amine compounds In the synthesis examples, amine compounds obtained by the following procedure or commercially available amine compounds were used.

[0060] [Amine compound 1] Priamine-1075 (manufactured by Croda Japan Co., Ltd., hydrogenated, dimer:trimmer ≈ 98:2) [Amine compound 2] Priamine-1074 (manufactured by Croda Japan Co., Ltd., hydrogenated, dimer:trimmer ≈ 95:5) [Amine compound 3] 300 g of Priamine-1075 was subjected to thin-film distillation at 200°C for 60 minutes to obtain amine compound 3. The main chain of amine compound 3 was hydrogenated, with a dimer:trimer ratio of approximately 99.2:0.8. [Amine compound 4] Amine compound 4 was obtained by mixing 80.25 g of Priamine-1075 and 160.50 g of Priamine-1074. The main chain of amine compound 4 was hydrogenated, and the dimer:trimer ratio was approximately 96:4. [Amine compound 5] Amine compound 5 was obtained by mixing 160.50 g of Priamine-1075 and 80.25 g of Priamine-1074. The main chain of amine compound 5 was hydrogenated, and the dimer:trimer ratio was approximately 97:3. [Amine compound 6] 300 g of Priamine-1075 was subjected to thin-film distillation at 200°C for 45 minutes to obtain amine compound 6. The main chain of amine compound 6 was hydrogenated, with a dimer:trimann ratio of approximately 99.0:1.0. [Amine compound 7 (for comparative example)] Priamine-1073 (manufactured by Croda Japan Co., Ltd., no hydrogenation treatment, dimer:trimmer ≈ 95:5) [Amine compound 8 (for comparative example)] Priamine-1071 (manufactured by Croda Japan Co., Ltd., no hydrogenation treatment, dimer:trimmer ≈ 80:20) [Amine compound 9 (for comparative example)] 300 g of Priamine-1071 was subjected to thin-film distillation at 180°C for 60 minutes, and then hydrogenated with Raney nickel to obtain amine compound 9. The main chain of amine compound 9 was hydrogenated, with a dimer:trimer ratio of approximately 93:7. [Amine compound 10 (for comparative example)] 300 g of Priamine-1071 was subjected to thin-film distillation at 180°C for 45 minutes, and then hydrogenated with Raney nickel to obtain amine compound 10. The main chain of amine compound 10 was hydrogenated, with a dimer:trimer ratio of approximately 90:10.

[0061] (A) Maleimide compound Maleimide compounds were synthesized using the aforementioned amine compounds as raw materials by the following procedure. In each synthesis example, the maleimide compounds obtained had the dimer ratios shown in Table 1, with A in formula (1) being a hydrocarbon group derived from dimer acid and trimer acid, and whether or not group A was hydrogenated was also as shown in Table 1.

[0062] [Synthesis Example 1] In a 1 L four-necked glass flask equipped with a stirrer, Dean-Stark tube, cooling condenser, and thermometer, 240.75 g (0.45 mol) of amine compound 1, 97.2 g (0.99 mol) of maleic anhydride, and 150 g of toluene were added and stirred at 80°C for 3 hours to synthesize amical. Subsequently, 40 g of methanesulfonic acid was added, and the temperature was raised to 110°C. The mixture was stirred for 24 hours while removing the by-product water by distillation, and the reaction mixture was washed five times with 200 g of deionized water. Then, 297.1 g (yield 95%, Mn1050) of the target product (A-1) was obtained as a brown liquid at room temperature by vacuum stripping at 60°C.

[0063] [Synthesis Example 2] By simply replacing amine compound 1 in Synthesis Example 1 with an equimolar amount of amine compound 2, and performing the other procedures in the same manner, 297.0 g of the target product (A-2) in a brown liquid state was obtained (yield 95%, Mn 1130).

[0064] [Synthesis Example 3] By simply replacing amine compound 1 in Synthesis Example 1 with an equimolar amount of amine compound 3, and performing the other steps in the same manner, 296.0 g of the target product (A-3) in a brown liquid state was obtained (yield 94%, Mn1010).

[0065] [Synthesis Example 4] By simply replacing 240.75g of amine compound 1 with 240.75g of amine compound 4 in Synthesis Example 1, and performing the other steps in the same manner, 297.1g (yield 95%, Mn1130) of the target product (A-4) in a brown liquid was obtained.

[0066] [Synthesis Example 5] By simply replacing 240.75g of amine compound 1 with 240.75g of amine compound 5 in Synthesis Example 1, and performing the other steps in the same manner, 296.7g (yield 95%, Mn1090) of the target product (A-5) in a brown liquid was obtained.

[0067] [Synthesis Example 6] By simply replacing amine compound 1 in Synthesis Example 1 with an equimolar amount of amine compound 6, and performing the other steps in the same manner, 296.0 g of the target product (A-6) in a brown liquid state was obtained (yield 94%, Mn1010).

[0068] [Synthesis Example 7] By simply replacing amine compound 1 in Synthesis Example 1 with an equimolar amount of amine compound 7, and performing the other steps in the same manner, 294.0 g of the target product (A-7) in a brown liquid state was obtained (yield 94%, Mn 1160, for comparative example).

[0069] [Synthesis Example 8] By simply replacing amine compound 1 in Synthesis Example 1 with an equimolar amount of amine compound 8, and performing the other steps in the same manner, 290.8 g of the target product (A-8) in a brown liquid state was obtained (yield 93%, Mn 1380, for comparative example).

[0070] [Synthesis Example 9] By simply replacing amine compound 1 in Synthesis Example 1 with an equimolar amount of amine compound 9, and performing the other steps in the same manner, 291.0 g of the target product (A-9), a brown liquid, was obtained (yield 93%, Mn 1200, for comparative example).

[0071] [Synthesis Example 10] By simply replacing amine compound 1 in Synthesis Example 1 with an equimolar amount of amine compound 10, and performing the other steps in the same manner, 291.0 g of the target product (A-10) in a brown liquid form (yield 93%, Mn 1220, for comparative example) was obtained.

[0072] <Viscosity> For each synthesized maleimide compound, the viscosity was measured using a Brookfield-type rotational viscometer at a measurement temperature of 25°C and a spindle rotation speed of 5 rpm, in accordance with the method described in JIS Z8803:2011. The results are shown in Table 1.

[0073] (B) Catalyst (B-1): 2,5-dimethyl-2,5-di(t-butylperoxy)hexane (trade name: Trigonox 101, manufactured by Kayaku Nurion Co., Ltd.)

[0074] <Sample Preparation> Each component was placed in a plastic container according to the mixing ratios shown in Table 2 and mixed using a Thinky mixer (manufactured by Thinky Co., Ltd., product name: Awatori Rentaro ARE-310) to prepare each resin composition.

[0075] <Dielectric properties and heat resistance> A 70mm x 70mm, 200μm thick frame was prepared, and each resin composition was sandwiched between two 50μm thick release-treated PET films (E7006, manufactured by Toyobo). The mixture was then molded using a vacuum press (manufactured by Nikko Materials) at 160°C for 5 minutes to produce a cured product (molded film). The molded film was post-cured at 180°C for 1 hour to obtain a cured resin film. A network analyzer (manufactured by Keysight, product name: E5063-2D5) and a stripline (manufactured by Keycom Co., Ltd.) were connected to the cured resin film, and the relative permittivity and dielectric loss tangent of the cured resin film at frequencies of 10GHz and 28GHz were measured. Furthermore, the cured resin film was left at 150°C for 48 hours, and the relative permittivity and dielectric loss tangent of the cured resin film were similarly measured at frequencies of 10 GHz and 28 GHz.

[0076] <Hygroscopicity> A 15mm x 5mm, 5mm thick mold was prepared. Each resin composition was sandwiched between two 50μm thick release-treated PET films (E7006, manufactured by Toyobo), and molded using a vacuum press (manufactured by Nikko Materials) at 160°C for 5 minutes to produce a cured product. The cured product was post-cured at 180°C for 1 hour, and its weight was measured. Subsequently, it was left in a constant temperature bath at 85°C and 85% humidity for 24 hours, and its weight was measured again. The weight increase rate after moisture absorption was calculated as the hygroscopicity (%).

[0077] [Table 1]

[0078] (A) Maleimide compounds having a dimer ratio of 95% by mass or more and hydrogenated groups had a low viscosity of 7.0 Pa·s or less at 25°C as measured under the above conditions.

[0079] [Table 2]

[0080] The composition of the example, which contains a (A) maleimide compound having a dimer ratio of 95% by mass or more and a hydrogenated group, exhibited excellent workability, low dielectric constant and dielectric loss tangent even at high frequencies of 10-28 GHz after curing, and excellent dielectric properties, with little change in dielectric constant and dielectric loss tangent even after prolonged storage at high temperatures compared to before storage. Furthermore, the cured product of the composition of the example had low hygroscopicity and was less affected by moisture absorption. On the other hand, even when the dimer ratio was 95% by mass or more, the cured product of the composition of Comparative Example 1, which contained a maleimide compound having a group that had not been hydrogenated, showed a particularly large dielectric loss tangent value after heat treatment, and its dielectric properties deteriorated with high-temperature storage. Furthermore, the cured products of the compositions of Comparative Examples 2 to 4, which contained a maleimide compound with a dimer ratio of less than 95% by mass, showed a large dielectric loss tangent value after heat treatment and also exhibited high hygroscopicity. [Explanation of symbols]

[0081] 1 Prepreg 2 Curable resin composition 3. Fiber base material 11 Metal-clad laminate 12 Insulating layer 13 Metal foil 21 Printed circuit board 22 wiring layer

Claims

1. (A) Maleimide compounds represented by the following general formula (1), having a viscosity of 7.0 Pa·s or less at 25°C and a number-average molecular weight of 1150 or less: 98-99.9% of the composition 【Chemistry 1】 (In formula (1), A represents a hydrocarbon group derived from dimer acid and trimer acid.) and (B) Catalysts that are organic peroxides A curable resin composition that contains and hardens upon heating, A semiconductor encapsulant comprising a curable resin composition in which A is a hydrogenated group, wherein the proportion of hydrocarbon groups derived from dimer acid among the hydrocarbon groups derived from dimer acid and trimer acid is 97% by mass or more.

2. (A) Maleimide compounds represented by the following general formula (1), having a viscosity of 7.0 Pa·s or less at 25°C and a number-average molecular weight of 1150 or less: 98-99.9% of the composition 【Chemistry 2】 (In formula (1), A represents a hydrocarbon group derived from dimer acid and trimer acid.) and (B) Catalysts that are organic peroxides A curable resin composition that contains and hardens upon heating, In formula (1), A is a hydrogenated group in which the proportion of hydrocarbon groups derived from dimer acid among the hydrocarbon groups derived from dimer acid and trimer acid is 97% by mass or more. The prepreg comprises a curable resin composition and a fiber substrate.

3. (A) Maleimide compounds represented by the following general formula (1) and having a viscosity of 7.0 Pa·s or less at 25°C: 98-99.9% of the composition 【Transformation 3】 (In formula (1), A represents a hydrocarbon group derived from dimer acid and trimer acid.) and (B) Catalysts that are organic peroxides A curable resin composition that contains and hardens upon heating, An interlayer insulating material comprising a curable resin composition in which A is a hydrogenated group, wherein the proportion of hydrocarbon groups derived from dimer acid among the hydrocarbon groups derived from dimer acid and trimer acid is 97% by mass or more.

4. (A) Maleimide compounds represented by the following general formula (1), having a viscosity of 7.0 Pa·s or less at 25°C and a number-average molecular weight of 1150 or less: 98-99.9% of the composition 【Chemistry 4】 (In formula (1), A represents a hydrocarbon group derived from dimer acid and trimer acid.) and (B) Catalysts that are organic peroxides A curable resin composition that contains and hardens upon heating, A printed circuit board having a cured product of a curable resin composition, wherein A in formula (1) is a group in which the proportion of hydrocarbon groups derived from dimer acid among the hydrocarbon groups derived from dimer acid and trimer acid is 97% by mass or more, and which has been hydrogenated.

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