Maleimide resin mixture, curable resin composition, varnish, and cured product thereof

Abstract

The invention provides a maleimide resin mixture, a curable resin composition and a cured product thereof, wherein the maleimide resin mixture has excellent low dielectric loss tangent and excellent storage stability in a varnish state. A maleimide resin mixture comprising a maleimide resin having repeating units represented by formulae (a) and (b), and bis (3-ethyl-5-methyl-4-maleimide phenyl) methane represented by formula (c), the maleimide resin mixture being characterized in that the content of the bismaleimide represented by formula (c) is 5.0 to 30.0 area% in terms of GPC area percentage in the total amount of the maleimide resin mixture. In the formula, m is the average value of the number of repetitions, 0 lt; mlt; mlt; 200). N is the average value of repetition numbers, 0 lt; nlt; 100). (a) and (b) are respectively bonded by *, and the repeated position can be random.

Description

Technical Field

[0001] This invention relates to maleimide resin mixtures, curable resin compositions, varnishes and their cured forms, suitable for use in semiconductor sealing materials, printed circuit boards, laminates and other electrical and electronic components, lightweight and high-strength materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and 3D printing applications. Background Technology

[0002] In recent years, the requirements for the characteristics of laminates that house electrical and electronic components have become more extensive and sophisticated due to the expanding applications. In the past, semiconductor chips were mainly mounted on metal lead frames, but semiconductor chips with higher processing power, such as central processing units (CPUs), are increasingly mounted on laminates made of polymer materials.

[0003] The rapidly developing fifth-generation communication system, "5G," is expected to offer greater capacity and higher speeds. As 5G utilizes increasingly higher frequencies, reducing transmission losses is crucial for achieving high-speed communication at these frequencies, requiring substrate materials with superior dielectric properties. Transmission losses on printed circuit boards originate from conductor losses and dielectric losses. As described in Non-Patent Document 1, dielectric loss α... D The relative permittivity ε of the dielectric material γ The square root of the dielectric loss is proportional to the dielectric loss tangent tanδ. Therefore, to reduce transmission loss, it is more effective to improve the relative permittivity ε than to increase the dielectric constant tanδ. γ Improving the dielectric loss tangent (tanδ) is more effective. Materials with low dielectric loss tangents include thermoplastic materials such as PTFE (polytetrafluoroethylene) or LCP (liquid crystal polymer), but they lack moldability compared to thermosetting resins. Therefore, there is a need to develop thermosetting resins with excellent dielectric properties. Specifically, a dielectric loss tangent of 0.0016 or less, and more preferably 0.0012 or less, at a frequency of 10 GHz and a temperature of 25°C is preferred. These values ​​are what the market demands, for example, values ​​equivalent to those of MEGTORON8 manufactured by Panasonic Corporation. See Panasonic Holdings Corporation press release "Development of 'Low Transmission Loss Multilayer Substrate Material MEGTRON8' for High-Speed ​​Communication Network Equipment".

[0004] Furthermore, semiconductor packaging (hereinafter referred to as PKG) used in smartphones and other devices requires thinner PKG substrates to meet the demands for miniaturization, thinning, and high density. However, thinner PKG substrates reduce rigidity, leading to defects such as significant warping due to the heating during PKG soldering onto the motherboard (PCB). To mitigate this, PKG substrate materials with a high Tg (260°C) above the soldering temperature are required.

[0005] In view of this situation, maleimide resin has been explored as a material for printed circuit boards in the high-frequency field in recent years. Maleimide resin itself has a high crosslinking density, thus exhibiting high heat resistance. However, as pointed out in Patent Document 1 below, bismaleimide compounds with an imide structure in the molecule have high crystallinity and a relatively high melting point of about 150°C, close to the self-reaction temperature of about 170 to 180°C. Therefore, this material is difficult to formulate into impregnating varnishes and then impregnate and dry, or to melt-mix with epoxy resin, hardener, filler, etc., and then mold into a molding material.

[0006] [Existing Technical Documents]

[0007] [Non-patent literature]

[0008] Non-Patent Document 1: “Factors of Signal Loss in High-Speed ​​Signal Transmission on Printed Circuit Boards”, 29th Spring Lecture Conference of The Japan Institute of Electronics Packaging, Session ID: 16P1-17.

[0009] [Patent Literature]

[0010] Patent document 1: Japanese Patent Application Publication No. 2018-12671. Summary of the Invention

[0011] [The problem that the invention aims to solve]

[0012] The present invention was developed in view of this situation, and its object is to provide maleimide resin mixtures, curable resin compositions and their cured products with excellent low dielectric loss tangent, solvent solubility and storage stability in the varnish state.

[0013] [Methods used to solve problems]

[0014] That is, this invention relates to the following [1] to

[12] . In addition, in this application, "(numerical value 1) to (numerical value 2)" includes upper and lower limits.

[0015] [1] A maleimide resin mixture comprising a maleimide resin having repeating units of the following formulas (a) and (b), and bis(3-ethyl-5-methyl-4-maleimidephenyl)methane as shown in the following formula (c),

[0016] In the total amount of maleimide resin mixture, the content of bis(3-ethyl-5-methyl-4-maleimidephenyl)methane as shown in formula (c) above is 5.0 to 30.0% of the GPC area percentage.

[0017]

[0018] In the above formula, m is the average value of the repetition number, where 0 < m < 200. n is the average value of the repetition number, where 0 < n < 100. (a) and (b) are bonded by * respectively, and the repetition positions can be random.

[0019] [2]

[0021] The maleimide resin mixture as described in the previous item [1] is obtained by reacting a styrene / maleic anhydride copolymer, 4,4'-methylenebis(2-ethyl-6-methylaniline), and maleic anhydride. [3]

[0023] In the maleimide resin mixture as described in the previous item [2], the weight average molecular weight of the aforementioned styrene / maleic anhydride copolymer is 900 or more and less than 10,000. [4]

[0025] A curable resin composition contains the maleimide resin mixture as described in any one of the previous items [1] to [3]. [5]

[0027] In the curable resin composition as described in the previous item [4], it further contains at least one or more selected from the group consisting of maleimide resins other than the aforementioned maleimide resin mixture, polyphenylene ether compounds, compounds having ethylenically unsaturated bonds, cyanate ester resins, polybutadiene and its modified products, polystyrene and its modified products, polyethylene and its modified products.

[0028] [6] The curable resin composition as described in the previous item [4] or [5] further contains a curing accelerator. [7]

[0030] The curable resin composition as described in any one of the previous items [4] to [6] is for a printed circuit board. [8]

[0032] A varnish is composed of the maleimide resin mixture as described in any one of the previous items [1] to [3] and an organic solvent. [9]

[0034] A varnish is composed of the curable resin composition as described in any one of the previous items [4] to [7] and an organic solvent.

[10]

[0036] A cured product is obtained by curing the maleimide resin mixture as described in any one of the previous items [1] to [3].

[11]

[0038] A hardener obtained by hardening the hardening resin composition as described in any one of the preceding items [4] to [7].

[12]

[0040] The hardened material described in

[10] or

[11] above has a dielectric loss tangent of less than 0.0016 at a frequency of 10 GHz measured at 25 °C.

[0041] [Effects of the invention]

[0042] According to the present invention, maleimide resin mixtures and curable resin compositions with low dielectric loss tangent, excellent solvent solubility, and excellent storage stability in varnish state can be provided. Attached Figure Description

[0043] Figure 1 The GPC diagram represents Example 1.

[0044] Figure 2 The GPC diagram represents Example 2.

[0045] Figure 3 The GPC diagram represents Example 3.

[0046] Figure 4 The GPC diagram represents Example 4.

[0047] Figure 5 The GPC diagram represents Example 5.

[0048] Figure 6 The GPC diagram represents Example 6.

[0049] Figure 7 The GPC diagram represents Example 7.

[0050] Figure 8 The GPC chart represents Comparison Example 1.

[0051] Figure 9 The GPC chart represents Comparative Example 2.

[0052] Figure 10 The GPC diagram represents Example 8. Detailed Implementation

[0053] The embodiments of the present invention (hereinafter referred to as "this embodiment") are further described in detail below.

[0054] The maleimide resin mixture of the present embodiment is a maleimide resin having repeating units of the following formulas (a) and (b), and a maleimide resin mixture composed of bis(3-ethyl-5-methyl-4-maleimidophenyl)methane represented by the following formula (c). Since the maleimide resin of the present embodiment contains asymmetric alkyl substituents at the 2-position and 6-position of the aromatic rings contained in the following formulas (b) and (c), the change in dielectric properties caused by water absorption can be controlled, and the crystallinity can be disrupted, and the solvent solubility and solvent storage stability can be improved.

[0055]

[0056] In the above formulas, (a) and (b) are bonded by * respectively, and the repeating positions may be random. m is the average value of the number of repetitions, more preferably 0 < m < 200, still more preferably 1 ≤ m < 100, yet more preferably 1 < m < 100, and particularly preferably 5 < m < 80. n is the average value of the number of repetitions, more preferably 0 < n < 100, still more preferably 0 < n < 90, yet more preferably 0 < n < 80, still more preferably 1 ≤ n < 30, and particularly preferably 1.0 < n < 30. The values of m and n are derived from the styrene / maleic anhydride copolymer of the raw materials. The values of m and n can be obtained from the weight average molecular weight determined by gel permeation chromatography (GPC) of the styrene / maleic anhydride copolymer, the ratio of styrene to anhydride determined from the acid value in the styrene / maleic anhydride copolymer, the molecular weight of the styrene monomer, and the molecular weight of the maleic anhydride.

[0057]

[0058] In the total amount of the maleimide resin mixture of the present embodiment, the content of bis(3-ethyl-5-methyl-4-maleimidophenyl)methane represented by the above formula (c) is more preferably 5.0 to 30.0 area% in terms of GPC (gel permeation chromatography) area percentage, and still more preferably 10.0 to 20.0 area%. When it exceeds 30.0%, the proportion of the maleimide group of the polar group increases, so the dielectric properties will deteriorate, or bis(3-ethyl-5-methyl-4-maleimidophenyl)methane represented by the above formula (c) will precipitate as crystals, and the storage stability in the varnish state will deteriorate. On the other hand, when it is less than 5.0%, the proportion of the crosslinkable maleimide group becomes small, and the hardness or heat resistance will deteriorate.

[0059] An organic solvent can be added to the maleimide resin mixture of the present embodiment to form a varnish. Examples of the organic solvent that can be used include toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. In the varnish, the content of the maleimide resin mixture of the present embodiment is more preferably 30 to 90% by weight, and still more preferably 40 to 80% by weight.

[0060] The method for preparing the maleimide resin mixture in this embodiment is not particularly limited, and it can be obtained by reacting a styrene / maleic anhydride copolymer, 4,4'-methylenebis(2-ethyl-6-methylaniline), and maleic anhydride. Alternatively, 4,4'-methylenebis(2-ethyl-6-methylaniline) and maleic anhydride can be reacted to produce bis(3-ethyl-5-methyl-4-maleimidephenyl)methane as shown in formula (c).

[0061] Specifically, it can be obtained by a first step of imidizing styrene / maleic anhydride copolymer and 4,4'-methylenebis(2-ethyl-6-methylaniline) in a solvent in the presence of a catalyst, followed by a second step of adding maleic anhydride and imidizing it. However, the order of the steps is not limited, and the order of the steps can be interchanged or carried out simultaneously.

[0062] Alternatively, after obtaining the maleimide resin mixture, bis(3-ethyl-5-methyl-4-maleimidephenyl)methane as shown in formula (c) above may be added.

[0063] In the imidization step described above, an amino group of 4,4'-methylenebis(2-ethyl-6-methylaniline) is added in excess of 1 mole of anhydride groups relative to the styrene / maleic anhydride copolymer. This prevents gelation caused by three-dimensional crosslinking in the reaction steps. At this time, the preferred range for the value (α / β) of the molar number of amino groups (α) of 4,4'-methylenebis(2-ethyl-6-methylaniline) divided by the molar number of anhydride groups (β) of the styrene / maleic anhydride copolymer is 1.1 to 20, more preferably 1.1 to 15, and more preferably 1.1 to 10. When α / β is below the above range, gelation will occur, making manufacturing difficult. Furthermore, when α / β is above the above range, the amount of polystyrene introduced will decrease, so a sufficient improvement in electrical properties cannot be expected. Examples of solvents used include aromatic solvents such as toluene and xylene, aliphatic solvents such as cyclohexane and n-hexane, ethers such as diethyl ether and diisopropyl ether, ester solvents such as ethyl acetate and butyl acetate, and ketone solvents such as methyl isobutyl ketone and cyclopentanone, which are non-water-soluble solvents. However, these are not limited to these, and two or more solvents may be used in combination. In addition to the aforementioned non-water-soluble solvents, aprotic polar solvents may also be used. Examples include dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidineone, and N-methylpyrrolidone, and two or more of these may also be used in combination. When using aprotic polar solvents, it is preferable to use a solvent with a boiling point higher than that of the non-water-soluble solvents used in combination. During the reaction, hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, p-toluenesulfonic acid, methanesulfonic acid, Lewis acids such as aluminum chloride and zinc chloride, activated clay, acid clay, white carbon, zeolite, silica alumina, and acidic ion exchange resins can be used as catalysts. These can be used alone or in combination of two or more. The amount of catalyst used is usually 0.1 to 0.8 moles relative to 1 mole of the amino group of the amine compound used, preferably 0.2 to 0.7 moles. If too much catalyst is used, the viscosity of the reaction solution will be too high, which may make it difficult to stir; if too little catalyst is used, the reaction may be slowed down. In the imidization of the second step mentioned above, maleic anhydride is added in an equivalent amount or more, preferably 1.1 equivalents or more, relative to the number of moles of 4,4'-methylenebis(2-ethyl-6-methylaniline) that were excessively added in the first step. This allows all the remaining amino groups to be maleiminated, thereby producing the compounds shown in formulas (b) and (c). Furthermore, the co-catalyst for imidization can be used alone or in combination with basic co-catalysts such as triethylamine. When using sulfonic acid as a catalyst, it can be neutralized with an alkali metal such as sodium hydroxide or potassium hydroxide before proceeding to the extraction step. The extraction step can use an aromatic hydrocarbon solvent such as toluene or xylene alone, or in combination with a non-aromatic hydrocarbon such as cyclohexane or toluene. After extraction, the organic layer is washed with water until the water becomes neutral, and the solvent is distilled off using an evaporator or similar apparatus. This process yields the desired maleimide resin with an intramolecular polystyrene structure.

[0064] Styrene / maleic anhydride copolymers can be obtained by copolymerizing styrene and maleic anhydride. Polymerization methods can include free radical polymerization or coordination polymerization, various living polymerization methods, and any well-known method, such as reacting styrene and maleic anhydride in toluene in the presence of a free radical polymerization initiator. The resulting polymer can be a random polymer or a periodic copolymer, or a block polymer or a cross-linked copolymer. Furthermore, the stereoregularity of the polystyrene segments can be syndiotactic or atactic, homologous, or any of the following.

[0065] The weight-average molecular weight (Mw) of the desired styrene / maleic anhydride copolymer, as determined by gel permeation chromatography (GPC), is preferably 100 or more and less than 10,000, more preferably 1,500 or more and less than 9,000, and even more preferably 2,000 or more and less than 8,000. Furthermore, the number-average molecular weight (Mn) is preferably 1,000 or more and less than 5,000, more preferably 1,000 or more and less than 3,000. If the weight-average molecular weight (Mw) and number-average molecular weight (Mn) do not reach the above-mentioned upper limits, gelation can be prevented, and purification by water washing is easier. Furthermore, if the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are above the above-mentioned lower limits, the target compound will not volatilize during the solvent removal step.

[0066] The weight-average molecular weight (Mw) of the maleimide resin mixture of this embodiment, as determined by gel permeation chromatography (GPC), is preferably 900 or more and less than 9000, more preferably 1000 or more and less than 7000, and particularly preferably 2000 or more and less than 6000. Furthermore, the number-average molecular weight (Mn) is preferably 1000 or more and less than 5000, more preferably 1000 or more and less than 2000. If the weight-average molecular weight (Mw) and number-average molecular weight (Mn) do not reach the above-mentioned upper limits, the solvent solubility is excellent, and therefore this is preferred. Furthermore, if they are above the above-mentioned lower limits, the volatile matter during molding is less, and molding defects are less likely to occur, which is also preferred.

[0067] The maleimide resin mixture of this embodiment can be used to determine the maleimide equivalent by potentiometric titration. The maleimide equivalent of the maleimide resin mixture of this embodiment is preferably 500 g / eq or more and less than 3000 g / eq, more preferably 500 g / eq or more and less than 2000 g / eq, and particularly preferably 600 g / eq or more and less than 1500 g / eq. If the maleimide equivalent does not reach the above upper limit, it contains maleimide groups of cross-linking components, which can enter the hardened network and reduce molding defects, and can also increase the glass transition temperature (Tg), thus it is more preferred. Furthermore, if it is 100 g / eq or more, the cured product contains fewer highly polar maleimide groups, thus suppressing property changes caused by water absorption, thus it is more preferred.

[0068] The curing composition of this embodiment may contain a polymerization inhibitor in addition to the maleimide resin mixture of this embodiment. The presence of a polymerization inhibitor improves storage stability and allows for control of the reaction initiation temperature. Controlling the reaction initiation temperature facilitates flowability and makes the B-stage of prepreg forming easier without compromising its permeability to glass cloth, etc. During prepreg forming, if the polymerization reaction proceeds excessively, difficulties such as lamination difficulties in the lamination step can easily occur. Examples of usable polymerization inhibitors include phenolic, sulfur-based, phosphorus-based, hindered amine-based, nitroso-based, and nitroxide-radical-based polymerization inhibitors. The polymerization inhibitor may be added during the synthesis of the maleimide resin mixture of this embodiment or after synthesis. Furthermore, the polymerization inhibitor may be used alone or in combination of two or more. The amount of polymerization inhibitor used is typically 0.008 to 1 part by weight relative to 100 parts by weight of the resin component, preferably 0.01 to 0.5 parts by weight. These polymerization inhibitors may be used alone or in combination of two or more. In this embodiment, phenolic, hindered amine, nitroso, and nitroxide free radical systems are preferred.

[0069] Specific examples of phenol-based polymerization inhibitors include 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-p-ethylphenol, stearyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylaniline)-1,3,5-trimethylaniline. Monophenols such as 2,4-bis[(octylthio)methyl]-o-cresol; 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,4'-butylenebis(3-methyl-6-tert-butylphenol), triethylene glycol-bis[3-(3-tert-butyl-5-methyl- [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamamide), 2,2-thio-divinylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,5-di-tert-butyl-4-hydroxybenzyl phosphate diethyl ester, 3,9-bis[3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,9-di-tert-butyl-4-hydroxybenzyl phosphate diethyl ester, 3,9-di-[3,5-di-tert-butyl-4-hydroxyphenyl)propionate] [1,1-Dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, bis(3,5-di-tert-butyl-4-hydroxybenzylsulfonate ethyl ester) calcium and other bisphenols; 1,1,3-trimethyl-2,4,6-trimethyl-2,4,6-trimethyl-3,5-dimethyl-4-hydroxy-5-tert-butylphenyl)butane, 1,1,3-trimethyl-2,4,6-trimethyl-3,5-dimethyl-4-hydroxy-5-tert-butylphenyl)butane, 1,1,3-trimethyl-2,4,6-trimethyl-3,5-dimethyl-4-hydroxy-5-tert-butylphenyl)butane, 1,1,3-trimethyl-2,4,6-trimethyl-4,4,5 ... -di-tert-butyl-4-hydroxybenzyl)benzene, tetra-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-tert-butylphenyl)butyrate]diol ester, tris(3,5-di-tert-butyl-4-hydroxybenzyl)-triisocyanate, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-S-tris(-) -2,4,6-(1H,3H,5H)triones, tocopherols, and other high molecular weight phenols.

[0070] Specific examples of sulfur-based polymerization inhibitors include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearate-3,3'-thiodipropionate.

[0071] Specific examples of phosphorus-based polymerization inhibitors include triphenyl phosphite, diphenyl isodecanyl phosphite, phenyl phosphite diisodecyl phosphite, tri(nonylphenyl) phosphite, diisodecyl pentaerythritol phosphite, tris(2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetrayl bis(octadecyl) phosphite, cyclic neopentanetetrayl bis(2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetrayl bis(2,4-di-tert-butyl-4-methylphenyl) phosphite, and bis[2- Phosphites such as tert-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl]hydrophosphite; oxaphosphazene oxides such as 9,10-dihydro-9-oxa-10-phosphazene-10-oxide, 10-(3,5-di-tert-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphazene-10-oxide, and 10-decoxy-9,10-dihydro-9-oxa-10-phosphazene-10-oxide.

[0072] Specific examples of hindered amine polymerization inhibitors include ADK STAB (registered trademark) LA-40MP, ADK STAB LA-40Si, ADK STAB LA-402AF, ADK STAB LA-87, ADK STAB LA-82, ADK STAB LA-81, ADK STAB LA-77Y, ADK STAB LA-77G, ADK STAB LA-72, ADK STAB LA-68, ADK STAB LA-63P, ADK STAB LA-57, and ADK STAB... LA-52 (the above are manufactured by ADEKA Corporation), Chimassorb (registered trademark) 2020FDL, Chimassorb944FDL, Chimassorb944LD, Tinuvin (registered trademark) 622SF, Tinuvin PA144, Tinuvin 765, Tinuvin 770DF, Tinuvin XT55FB, Tinuvin 111FDL, Tinuvin 783FDL, Tinuvin 791FB (the above are manufactured by BASF Corporation), etc., but not limited to these.

[0073] Specific examples of nitrosyl-based polymerization inhibitors include p-nitrosophenol, N-nitrosodiphenylamine, ammonium salts of N-nitrosophenylhydroxylamine, and (copper ferroin), with ammonium salts of N-nitrosophenylhydroxylamine (copper ferroin) being more preferred.

[0074] Specific examples of nitroxide radical-based polymerization inhibitors include di-tert-butyl nitroxide radical, 2,2,6,6-tetramethylpiperidine-1-oxide, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxide, 4-sideoxy-2,2,6,6-tetramethylpiperidine-1-oxide, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxide, 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxide, 4-acetoxy-2,2,6,6-tetramethylpiperidine-1-oxide, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxide, but are not limited to these.

[0075] The curable resin composition of this embodiment can use curable resins other than the maleimide resin and bis(3-ethyl-5-methyl-4-maleimidephenyl)methane of this embodiment, or any well-known material. Specifically, examples include maleimide compounds other than the maleimide resin and bis(3-ethyl-5-methyl-4-maleimidephenyl)methane of this embodiment, phenol resins, epoxy resins, amine resins, compounds containing vinyl unsaturated bonds, isocyanate resins, polyamide resins, polyimide resins, cyanate resins, acrylic resins, methacrylate resins, reactive ester resins, etc., and one type or multiple types can be used. In addition, considering the balance of heat resistance, adhesion, and dielectric properties, it is preferable to contain epoxy resin, compounds containing vinyl unsaturated bonds, or cyanate resin. By containing these curable resins, the brittleness of the cured product can be improved and the adhesion to the metal can be enhanced, and package breakage during solder reflow or reliability tests such as thermal cycling can be suppressed.

[0076] The amount of the aforementioned curable resin used is preferably 10 times or less by weight, more preferably 5 times or less by weight, and particularly preferably 3 times or less by weight relative to the maleimide resin mixture of this embodiment. Furthermore, a lower preferred value is 0.5 times or more by weight, more preferably 1 time or more by weight. If it is 10 times or less by weight, the heat resistance or dielectric properties of the maleimide resin mixture of this embodiment can be achieved.

[0077] The maleimide resins and maleimide compounds other than bis(3-ethyl-5-methyl-4-maleimidephenyl)methane, phenol resins, epoxy resins, amine resins, compounds containing vinyl unsaturated bonds, isocyanate resins, polyamide resins, polyimide resins, cyanate resins, and reactive ester resins of this embodiment may be used as exemplified below.

[0078] The maleimide resins and maleimide compounds other than bis(3-ethyl-5-methyl-4-maleimidephenyl)methane in this embodiment include: 4,4'-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylene bismaleimide, 2,2'-bis[4-(4-maleimidephenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenyl sulfone bismaleimide, 1,3-bis(3-maleimidephenoxy)benzene, 1,3-bis(4-maleimidephenoxy)benzene, and phenolic aryl alkyl maleimide compounds (ANILIX-MI, MITSUI). (manufactured by FINECHEMICALS), biphenyl aralkyl type maleimide compounds (a resin solution containing the maleimide compound (M2) described in Example 4 of Japanese Patent Application Publication No. 2009-001783 is solidified by distilling off the solvent under reduced pressure), diaminoisopropylphenylbenzene type maleimide (maleimide compound described in International Publication No. 2020 / 054601), maleimide compounds with an indane structure described in Japanese Patent No. 6629692 or International Publication No. 2020 / 217679, MATERIAL STAGE Vol. 18, No. 12 2019 『~Continued·Epoxy Resin CAS Number Story~ Hardener CAS Number Memorandum No. 31 Bismaleimide (1)』 or MATERIAL STAGE Vol. 19, No. 2 The maleimide compound described in 2019's '~Continued·Epoxy Resin CAS Number Story~ Hardener CAS Number Memorandum No. 32 Bismaleimide (2)'.

[0079] Phenolic resins: Polycondensates of phenols (phenol, alkyl-substituted phenols, aromatic-substituted phenols, hydroquinone, resorcinol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) with various aldehydes (formaldehyde, acetaldehyde, alkyl aldehydes, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzene, naphthal, glutaraldehyde, o-phthalaldehyde, crotonaldehyde, cinnamaldehyde, furfural, etc.); phenols with various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, chlorine, etc.). Diene, vinylidene Polymers of phenols, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropylbiphenyl, butadiene, isoprene, etc.; polycondensates of phenols and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, diphenyl ketone, etc.); phenolic resins obtained by polycondensation of phenols and substituted biphenyls (4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl, etc.) or substituted benzenes (1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis(hydroxymethyl)benzene, etc.); polycondensates of bisphenols and various aldehydes; and polyphenylene ether compounds.

[0080] Any well-known polyphenylene ether compound can be used, but from the viewpoint of heat resistance and electrical properties, polyphenylene ether compounds having vinyl unsaturated double bonds are preferred, and polyphenylene ether compounds having acryloyl, methacryl, or styrene structures are more preferred. Commercially available examples include SA-9000-111 (manufactured by SABIC, a polyphenylene ether compound with methacryl groups) or OPE-2St-1200 and OPE-2St-2200 (manufactured by Mitsubishi Gas Chemical, a polyphenylene ether compound with a styrene structure), etc.

[0081] The number-average molecular weight (Mn) of the polyphenylene ether compound is preferably 500 to 5000, more preferably 2000 to 5000, and even more preferably 2000 to 4000. If the molecular weight is less than 500, the heat resistance of the cured product tends to be insufficient. Furthermore, if the molecular weight is greater than 5000, the melt viscosity increases, making it difficult to achieve sufficient fluidity, thus leading to a tendency for poor molding. Additionally, reactivity decreases, the curing reaction requires a longer time, the amount of unreacted material entering the curing system increases, the glass transition temperature of the cured product decreases, and the heat resistance of the cured product tends to decrease.

[0082] Polyphenylene ether compounds with a number-average molecular weight of 500 to 5000 can exhibit excellent heat resistance and moldability while maintaining excellent dielectric properties. Furthermore, this number-average molecular weight can be specifically determined using techniques such as gel permeation chromatography.

[0083] Polyphenylene ether compounds can be obtained by redistribution reactions of high molecular weight polyphenylene ether compounds with a number average molecular weight of approximately 10,000 to 30,000, obtained through polymerization. Furthermore, by reacting these compounds with compounds containing vinyl unsaturated double bonds, such as methacryloyl chloride, acryloyl chloride, and chloromethylstyrene, free radical polymerization properties can be imparted. For example, polyphenylene ether compounds obtained through redistribution reactions can be obtained by heating high molecular weight polyphenylene ether compounds in a solvent such as toluene in the presence of a phenolic compound and a free radical initiator. As described above, polyphenylene ether compounds obtained through redistribution reactions have hardening hydroxyl groups derived from phenolic compounds at both ends of the molecular chain, thus maintaining higher heat resistance. Furthermore, the addition of functional groups at the ends of the molecular chain after modification of compounds containing vinyl unsaturated double bonds is also preferred. Additionally, polyphenylene ether compounds obtained through polymerization reactions exhibit excellent flowability, which is also preferred.

[0084] In the case of polyphenylene ether compounds obtained through polymerization, the molecular weight of the polyphenylene ether compound can be adjusted by adjusting the polymerization conditions, etc. Furthermore, when the polyphenylene ether compound is obtained through redistribution reaction, the molecular weight of the obtained polyphenylene ether compound can be adjusted by adjusting the conditions of the redistribution reaction, etc. More specifically, the amount of phenolic compound used in the redistribution reaction can be adjusted. That is, the more phenolic compound used, the lower the molecular weight of the obtained polyphenylene ether compound. In this case, the high molecular weight polyphenylene ether compound undergoing the redistribution reaction can be poly(2,6-dimethyl-1,4-phenylene ether), etc. Furthermore, the phenolic compound used in the aforementioned redistribution reaction is not particularly limited; for example, polyfunctional phenolic compounds having two or more phenolic hydroxyl groups in their molecules, such as bisphenol A, phenolic varnish, cresol varnish, etc., are preferred. These can be used alone or in combination of two or more.

[0085] Furthermore, the content of the polyphenylene ether compound is not particularly limited, but it is preferably 10 to 90% by weight relative to the total weight of the curing resin component, and more preferably 20 to 80% by weight. If the content of the polyphenylene ether compound is 10 to 90% by weight, a cured product with excellent heat resistance and other properties can be obtained, and the excellent dielectric properties of the polyphenylene ether compound can be fully utilized, which is preferred from this point of view.

[0086] Epoxy resins include: the aforementioned phenolic resins, epoxy propylene ether-based epoxy resins that are epoxypropylated from alcohols, alicyclic epoxy resins represented by 4-vinyl-1-cyclohexene diester or 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexane carboxylate, epoxy propylene amine-based epoxy resins represented by tetracyclooxypropyl diaminodiphenylmethane (TGDDM) or tricyclooxypropyl-p-aminophenol, and epoxy propylene ester-based epoxy resins.

[0087] Amine resins: diaminodiphenylmethane, diaminodiphenyl sulfone, isophorone diamine, naphthyldiamine, aniline phenolic varnish, o-ethyl aniline phenolic varnish, aniline resin obtained by the reaction of aniline with xylene chloride, aniline and substituted biphenyls (4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl, etc.) as described in Japanese Patent No. 6429862, or substituted phenyls (1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis(hydroxymethyl)benzene, etc.).

[0088] Compounds containing vinyl unsaturated bonds: Polycondensates of the aforementioned phenolic resins with halogenated compounds containing vinyl unsaturated bonds (chloromethylstyrene, allyl chloride, methylallyl chloride, acryloyl chloride, allyl chloride, etc.); phenols containing vinyl unsaturated bonds (2-allylphenol, 2-propenylphenol, 4-allylphenol, 4-propenylphenol, eugenol, isoeugenol, etc.) and halogenated compounds (4,4'-bis(methoxymethyl)-1 Polycondensates of 1'-biphenyl, 1,4-bis(chloromethyl)benzene, 4,4'-difluorodiphenyl ketone, 4,4'-dichlorodiphenyl ketone, 4,4'-dibromodiphenyl ketone, cyanuric trichloride, etc.; polycondensates of epoxy resins or alcohols with substituted or unsubstituted acrylates (acrylates, methacrylates, etc.); styrene resins; compounds containing allyl groups; compounds containing acenaphthylene (acenaphthylene, vinylnaphthalene, etc.). ), isocyanuric acid derivatives (TAIC manufactured by Mitsubishi Chemical Corporation, MA-DGIC, DA-MGIC, MeDAIC, L-DAIC, DD-1, etc. manufactured by Shikoku Chemical Co.), maleimide compounds (phenylmaleimide, 4,4'-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylene bismaleimide, 2,2'-bis[4-(4-maleimide phenoxy)phenyl]propane, 3, 3'-Dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenyl sulfone bismaleimide, 1,3-bis(3-maleimidephenoxy)benzene, 1,3-bis(4-maleimidephenoxy)benzene), phenolic aryl alkyl maleimide resins (ANILIX-MI, MITSUI) FINE CHEMICALS Co., Ltd.), biphenyl aralkyl type maleimide resin (a resin solution containing the maleimide resin (M2) described in Example 4 of Japanese Patent Application Publication No. 2009-001783 is solidified by distilling off the solvent under reduced pressure), and diaminoisopropylphenylbenzene type maleimide (maleimide resin described in International Publication No. 2020 / 054601).

[0089] Isocyanate resins: Aromatic diisocyanates such as terephthalic diisocyanate, isophthalic diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and naphthalene diisocyanate; isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hydrogenated xylene diisocyanate, and chlorinated diisocyanate. Polyisocyanates include aliphatic or alicyclic diisocyanates such as olefinic diisocyanates and lyamine diisocyanates; polyisocyanates such as one or more types of biuret bodies of isocyanate monomers or isocyanate bodies of the above-mentioned diisocyanate compounds in 3 quantities; and polyisocyanates obtained by ethyl esterification of the above-mentioned isocyanate compounds with polyol compounds via carbamate reaction.

[0090] Polyamide resin: a polymer made primarily of one or more amino acids (6-aminohexanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, p-aminomethylbenzoic acid, etc.) or lactams (ε-caprolactam, ω-undecanolactam, ω-laurolactam); or a polymer made primarily of one or more diamines and one or more dicarboxylic acids.

[0091] Diamines include: ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine, heptadecanediamine, octadecanediamine, nonadecanediamine, eicosanediamine, 2-methyl-1,5-diaminopentane, 2-methyl-1,8-diaminooctane, and other aliphatic diamines; cyclohexanediamine, bis-(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, and other alicyclic diamines; xylenediamine and other aromatic diamines.

[0092] Dicarboxylic acids: aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, and dodecanoic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, sodium isophthalate-5-sulfonate, hexahydroterephthalic acid, and hexahydroisophthalic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; and dialkyl esters and dichlorides of these dicarboxylic acids.

[0093] Polyimide resin: a polycondensation product of the aforementioned diamine and tetracarboxylic dianhydride.

[0094] Tetracarboxylic dianhydrides: 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 5-(2,5-di-side-oxytetrahydro-3-furanyl)-3-methyl-cyclohexene-1,2-dicarboxylic anhydride, pyrolithic dianhydride, 1,2,3,4-benzenetetracarboxylic anhydride, 3,3',4,4'-diphenylketonetetracarboxylic anhydride, 2,2',3,3'-diphenylketonetetracarboxylic anhydride, 3,3',4,4'-biphenyltetracarboxylic anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic anhydride, 2,2',3,3'-biphenyltetracarboxylic anhydride, methylene-4,4'-diphthalic anhydride, 1,1-ethylidene-4,4'-diphthalic anhydride, 2,2'-propylidene-4,4'-diphthalic anhydride, 1 2-Vinyl-4,4'-Diphthalic dianhydride, 1,3-Trimethylene-4,4'-Diphthalic dianhydride, 1,4-Tetramethylene-4,4'-Diphthalic dianhydride, 1,5-Pentamethylene-4,4'-Diphthalic dianhydride, 4,4'-Oxybisphthalic dianhydride, Thio-4,4'-Diphthalic dianhydride, Sulfonyl-4,4'-Diphthalic dianhydride, 1,3-Bis(3,4-dicarboxyphenyl)phthalic dianhydride, 1,3-Bis(3,4-dicarboxyphenoxy)phthalic dianhydride, 1,4-Bis(3,4-dicarboxyphenoxy)phthalic dianhydride, 1,3-Bis[2-(3,4-dicarboxyphenyl)-2-propyl]phthalic dianhydride, 1,4-Bis[2-(3,4-dicarboxyphenyl)]phthalic dianhydride -2-propyl]phenyl dianhydride, bis[3-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, bis[4-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, 1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 3,4,9,10-perylenetetracarboxylic acid dianhydride, 2,3,6,7-anthracitetetracarboxylic acid dianhydride, 1,2 7,8-Phenylacetetrate dianhydride, ethylenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3',4,4'-biscyclohexyltetracarboxylic dianhydride, carbonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-vinyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,1-ethylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2-propylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid)2-Dicarboxylic acid dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, rel-[1S,5R,6R]-3-oxabicyclo[3,2] [1] Octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 4-(2,5-disideloxytetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, ethylene glycol-bis-(3,4-dicarboxylic anhydride phenyl) ether, 4,4'-biphenylbis(triphenyltriacrylic acid monoester anhydride), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dihydride.

[0095] Cyanate ester resins: Cyanate ester compounds obtained by reacting phenol resin with cyanine halides, including, but not limited to, benzene dicyanate, benzene tricyanate, naphthalene dicyanate, biphenyl dicyanate, 2,2'-bis(4-cyanophenyl)propane (BisA-OCN, manufactured by Mitsubishi Gas Chemical Co., Ltd.), bis(4-cyanophenyl)methane, bis(3,5-dimethyl-4-cyanophenyl)methane, 2,2'-bis(3,5-dimethyl-4-cyanophenyl)propane, 2,2'-bis(4-cyanophenyl)ethane, 2,2'-bis(4-cyanophenyl)hexafluoropropane, bis(4-cyanophenyl)sulfone, bis(4-cyanophenyl) sulfide, phenolic varnish cyanate, and cyanate esters obtained by converting the hydroxyl groups of phenol / dicyclopentadiene cocondensates to cyanate ester groups.

[0096] Furthermore, the cyanate ester compound synthesized by the method disclosed in Japanese Patent Application Publication No. 2005-264154 is particularly preferred as a cyanate ester compound due to its excellent low hygroscopicity, flame retardancy, and dielectric properties.

[0097] In order to trimerize the cyanate groups and form symmetrical-trimer The cyclohexane cyanate resin may optionally contain catalysts such as zinc naphthenate, cobalt naphthenate, copper naphthenate, lead naphthenate, zinc octanoate, tin octanoate, lead acetylacetonate, dibutyltin maleate, or 18% Octope Zn (manufactured by HOPE CHEMICAL, Inc.) commercially available. The catalyst is typically used in amounts of 0.0001 to 0.10 parts by weight relative to 100 parts by weight of the total weight of the curing resin composition, and more preferably 0.00015 to 0.0015 parts by weight.

[0098] Reactive ester resin: As a curing agent for curable resins other than epoxy resins and maleimide resin mixtures of this embodiment, a compound having one or more active ester groups per molecule may be optionally used. The reactive ester resin is preferably a compound having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, or esters of heterocyclic hydroxyl compounds. This reactive ester resin is preferably obtained by a condensation reaction of at least one of a carboxylic acid compound and a thiocarboxylic acid compound with at least one of a hydroxyl compound and a thiol compound. In particular, from the viewpoint of improving heat resistance, an reactive ester resin obtained from a carboxylic acid compound and a hydroxyl compound is preferred, and an reactive ester resin obtained from a carboxylic acid compound and at least one of a phenol compound and a naphthol compound is even more preferred.

[0099] Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, icosinic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyrocyanic acid.

[0100] Examples of phenolic or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, acid phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthol, 1,6-dihydroxynaphthol, 2,6-dihydroxynaphthol, dihydroxydiphenyl ketone, trihydroxydiphenyl ketone, tetrahydroxydiphenyl ketone, phloroglucinol, phenylglycerol, dicyclopentadiene-type diphenol compounds, and phenolic varnishes. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

[0101] Preferred examples of reactive ester resins include reactive ester resins containing a dicyclopentadiene-type diphenol structure, reactive ester resins containing a naphthalene structure, reactive ester resins containing acetylated derivatives of phenolic varnish, and reactive ester resins containing benzoyl derivatives of phenolic varnish. More preferred examples are reactive ester resins containing a naphthalene structure and reactive ester resins containing a dicyclopentadiene-type diphenol structure. "Dicyclopentadiene-type diphenol structure" refers to a divalent structural unit composed of phenylene-dicyclopentylene-phenylene.

[0102] Commercially available reactive ester resins include, for example, reactive ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L-65TM", and "EXB-8150-65T" (manufactured by DIC); reactive ester resins containing a bisphenol A type structure such as the "UNIFINER series" (manufactured by UNITIKA); and reactive ester resins containing a naphthalene structure. "EXB9416-70BK" (manufactured by DIC Corporation); "DC808" (manufactured by Mitsubishi Chemical Corporation) of reactive ester resin containing acetylated phenolic varnish; "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) of reactive ester resin containing benzoylated phenolic varnish; "DC808" (manufactured by Mitsubishi Chemical Corporation) of reactive ester resin containing acetylated phenolic varnish; "EXB-9050L-62M" (manufactured by DIC Corporation) of reactive ester resin containing phosphorus atoms, etc.

[0103] The curable resin composition of this embodiment can be used with a curing accelerator (curing catalyst) to improve curability. For the purpose of promoting the self-polymerization or free radical polymerization of curable resins capable of free radical polymerization, such as olefin compounds or maleimide resins, a free radical polymerization initiator is preferred as a specific example of a curing accelerator that can be used. Examples of usable free radical polymerization initiators include ketone peroxides such as methyl ethyl ketone peroxide and acetyl acetone peroxide; diacyl peroxides such as benzoyl peroxide; dialkyl peroxides such as diisopropylbenzene peroxide and 1,3-bis-(tert-butyl isopropyl peroxide)benzene; peroxyketals such as tert-butyl peroxide of benzoate and tert-butylcyclohexane peroxide; neodecanoate peroxide α-isopropylphenyl ester; neodecanoate peroxide tert-butyl peroxide of neopentanoate; 2-ethylhexanoate peroxide-1,1,3,3-tetramethylbutyl peroxide; 2-ethylhexanoate peroxide tripentyl ester; 2-ethylhexanoate peroxide tert-butyl peroxide; and 3,5,5-trimethylhexanoate peroxide. The following are well-known curing accelerators, but not limited to: alkyl peroxides such as tert-butyl peroxide of methyl tert-butyl benzoate, 2-ethylhexyl percarbonate, bis(4-tert-butylcyclohexyl) percarbonate, tert-butyl isopropyl percarbonate, and 1,6-bis(tert-butyl carbonyloxy)hexane; organic peroxides such as tert-butyl hydroperoxide, cumene hydroperoxide, tert-butyl peroctanoate, and lauroyl peroxide; or azo compounds such as 4,4'-azobis(4-cyanopentanoic acid) and 2,2'-azobis(2,4-dimethylpentanones). More preferably are ketone peroxides, diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, alkyl peroxides, and peroxycarbonates, and even more preferably are dialkyl peroxides. The amount of free radical polymerization initiator added is preferably 0.01 to 5 parts by weight, and more preferably 0.01 to 3 parts by weight, relative to 100 parts by weight of the curable resin composition. If a large amount of free radical polymerization initiator is used, the molecular weight cannot be sufficiently elongated during the polymerization reaction.

[0104] Additionally, curing accelerators other than free radical polymerization initiators may be optionally added or used in combination. Specific examples of usable curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, and 2-ethyl-4-methylimidazole; tertiary amines such as 2-(dimethylaminomethyl)phenol or 1,8-diaza-bicyclo(5,4,0)undecene-7; phosphines such as triphenylphosphine; tetrabutylammonium salts; triisopropylmethylammonium salts; trimethyldecylammonium salts; cetyltrimethylammonium salts; quaternary ammonium salts such as hexadecyltrimethylammonium hydroxide; and triphenylbenzyl... Transition metal compounds (transition metal salts) such as quaternary phosphonium salts, triphenylethyl phosphonium salts, tetrabutyl phosphonium salts, etc. (the relative ions of quaternary salts include halogen ions, organic acid ions, hydroxide ions, etc., although not specifically specified, organic acid ions and hydroxide ions are particularly preferred), zinc compounds such as tin octoate, zinc carboxylate (zinc 2-ethylhexanoate, zinc stearate, zinc docosate, zinc myristate), or zinc phosphate (zinc octyl phosphate, zinc stearate phosphate, etc.). The amount of curing accelerator can be selected from 0.01 to 5.0 parts by weight relative to 100 parts by weight of epoxy resin.

[0105] The curable resin composition of this embodiment may contain a phosphorus-containing compound as a flame-retardant agent. The phosphorus-containing compound may be reactive or additive. Specific examples of phosphorus-containing compounds include trimethyl phosphate, triethyl phosphate, tricresyl phosphate, triterpenoid phosphate, cresol diphenyl phosphate, cresol-2,6-di(xylyl) phosphate, 1,3-phenylenebis(xylyl) phosphate, 1,4-phenylenebis(xylyl) phosphate, 4,4'-biphenyl(xylyl) phosphate, and other phosphate esters; 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, Phosphine derivatives such as 10(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; phosphorus-containing epoxy compounds obtained by reacting epoxy resin with the active hydrogen of the aforementioned phosphine derivatives, red phosphorus, etc., are more preferably phosphate esters, phosphine derivatives, or phosphorus-containing epoxy compounds, particularly preferably 1,3-phenylenebis(dithiomethyl phosphate), 1,4-phenylenebis(dithiomethyl phosphate), 4,4'-biphenyl(dithiomethyl phosphate), or phosphorus-containing epoxy compounds. The content of the phosphorus-containing compound is preferably in the range of 0.1 to 0.6 (weight ratio) of (phosphorus-containing compound) / (total epoxy resin). Below 0.1, the flame retardancy is insufficient; above 0.6, there are concerns about adverse effects on the hygroscopicity and dielectric properties of the cured material.

[0106] In addition, a light stabilizer may optionally be added to the curable resin composition of this embodiment. The light stabilizer is preferably a hindered amine light stabilizer (HALS). HALS is not particularly limited; examples include dibutylamine / 1,3,5-trimethylamine. Polycondensates of N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidinyl)butylamine, dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidinyl polycondensates, and poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-trimethyl...] =-2,4-dimethyl}{(2,2,6,6-tetramethyl-4-piperidinyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidinyl)imino}, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl] butyl malonate, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis(1-octoxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonic acid bis(1,2,2,6,6-pentamethyl-4-piperidinyl), etc. HALS can use only one type or use two or more types together.

[0107] Furthermore, an adhesive resin may be optionally incorporated into the curable resin composition of this embodiment. Examples of adhesive resins include butyraldehyde resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenol resins, epoxy-NBR resins, polyamide resins, polyimide resins, and polysiloxane resins, but are not limited to these. The amount of adhesive resin incorporated is preferably within a range that does not impair the flame retardancy and heat resistance of the cured product, and is preferably 0.05 to 50 parts by weight relative to 100 parts by weight of the resin component, more preferably 0.05 to 20 parts by weight.

[0108] Furthermore, the curable resin composition of this embodiment may optionally contain powders such as fused silica, crystalline silica, porous silica, alumina, zircon, calcium silicate, calcium carbonate, quartz powder, silicon carbide, silicon nitride, boron nitride, zirconium dioxide, aluminum nitride, graphite, forsterite, block talc, spinel, aluminum-rich andalusite, titanium dioxide, talc, clay, iron oxide asbestos, and glass powder, or inorganic fillers formed into spherical or pulverized forms. Especially when obtaining a curable resin composition for semiconductor sealing, the amount of the aforementioned inorganic filler used in the curable resin composition is typically 80 to 92% by weight, preferably in the range of 83 to 90% by weight.

[0109] The curable resin composition of this embodiment may optionally contain well-known additives. Specific examples of additives that can be used include surface treatment agents for fillers such as polybutadiene and its modified derivatives, modified acrylonitrile copolymers, polyphenylene ether, polystyrene, polyethylene, polyimide, fluororesin, polysiloxane gel, polysiloxane oil, and silane coupling agents, as well as release agents, carbon black, phthalocyanine blue, phthalocyanine green, and other colorants. The amount of these additives relative to 100 parts by weight of the curable resin composition is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, and particularly preferably 10 parts by weight or less. From the viewpoint of low water absorption and electrical properties, polybutadiene and its modified derivatives, polyphenylene ether, polystyrene, polyethylene, and fluororesin are preferred. From the viewpoint of electrical properties, adhesion, and low water absorption, polybutadiene and its modified derivatives are preferred. Specifically, examples include butadiene-based thermoplastic elastomers such as styrene-butadiene copolymers (SBR: RICON-100, RICON-181, RICON-184, all manufactured by CRAYVALLEY), and acrylonitrile-butadiene copolymers; and styrene-based thermoplastic elastomers such as styrene-butadiene-styrene copolymers (SBS), hydrogenated styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers (SIS), hydrogenated styrene-isoprene-styrene copolymers, and hydrogenated styrene (butadiene / isoprene)-styrene copolymers. These styrene-based thermoplastic elastomers can be used alone or in combination of two or more types. Among these high molecular weight copolymers, styrene-butadiene-styrene copolymers, hydrogenated styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, hydrogenated styrene-isoprene-styrene copolymers, and hydrogenated styrene (butadiene / isoprene)-styrene copolymers are preferred. In particular, styrene-isoprene-styrene copolymers, hydrogenated styrene-butadiene-styrene copolymers, hydrogenated styrene-isoprene-styrene copolymers, and hydrogenated styrene (butadiene / isoprene)-styrene copolymers have higher heat resistance and are less prone to oxidative degradation, and are therefore preferred. Specifically, there are septon (registered trademark) 1020, septon 2002, septon 2004F, septon 2005, septon 2006, septon 2063, septon 2104, septon 4003, septon 4044, septon 4055, septon 4077, septon 4099, septon 8004, septon 8006, septon 8007L, septon HG252, septon V9827, hybrar (registered trademark) 7125 (hydrogenated), hybrar 7215F, and hybrar 7311F (all manufactured by Kuraray Co., Ltd.).Furthermore, there is no particular limitation on the weight average molecular weight of styrene-based thermoplastic elastomers being 10,000 or higher. However, if the weight average molecular weight is too high, the compatibility with low molecular weight components (other than polyphenylene ether compounds) with a weight average molecular weight of around 50 to 1,000 and oligomer components with a weight average molecular weight of around 1,000 to 5,000 will deteriorate, making it difficult to ensure mixing and solvent stability. Therefore, a weight average of around 10,000 to 300,000 is preferred. Generally, in the case of compounds containing heteroatoms such as bismaleimide or polymaleimide, it is difficult to ensure compatibility with low-polarity compounds such as those mainly composed of hydrocarbons or only hydrocarbons in the aforementioned additives or curing resin components due to their polarity. On the other hand, the maleimide resin mixture of this embodiment is not designed with an active introduction of heteroatoms such as oxygen or nitrogen (few polar groups), so its compatibility with low-polarity materials with low dielectric loss tangents or compounds composed only of hydrocarbons is also excellent.

[0110] The curable resin composition of this embodiment is obtained by uniformly mixing the above-mentioned components in a specific ratio, typically pre-curing at 130 to 180°C for 30 to 500 seconds, and then further curing at 150 to 250°C for 2 to 15 hours to fully carry out the curing reaction and obtain the cured product of this embodiment. Alternatively, post-curing can be performed by uniformly dispersing or dissolving the components of the curable resin composition in a solvent or the like, and then removing the solvent.

[0111] The curable resin composition of this embodiment thus obtained possesses moisture resistance, heat resistance, and high adhesion. Therefore, the curable resin composition of this embodiment can be used in a wide range of fields requiring moisture resistance, heat resistance, and high adhesion. Specifically, it can be used as an insulating material, a laminate (printed circuit board, BGA substrate, build-up substrate, etc.), a sealing material, a photoresist, and other materials for various electrical and electronic components. In addition, besides molding materials and composite materials, it can also be used in coating materials, adhesives, 3D printing, and other fields. It is particularly helpful in semiconductor sealing for resisting solder reflow.

[0112] The semiconductor device is sealed with the curable resin composition of this embodiment. Examples of semiconductor devices include DIP (Dual In-line Package), QFP (Quad Flat Package), BGA (Ball Grid Array), CSP (Chip Scale Package), SOP (Small Outline Package), TSOP (Thin Small Outline Package), TQFP (Thin Quad Flat Package), etc.

[0113] The method for preparing the curable resin composition of this embodiment is not particularly limited; the components may be simply mixed uniformly, or prepolymerization may be performed. For example, the maleimide resin mixture of this embodiment may be prepolymerized by heating in the presence or absence of a catalyst or solvent. Similarly, in addition to the maleimide resin mixture of this embodiment, curing agents such as epoxy resin, amine compounds, other maleimide compounds, cyanate ester compounds, phenolic resins, and acid anhydride compounds, as well as other additives, may be added and prepolymerized. The mixing or prepolymerization of the components may be performed in the absence of a solvent using, for example, an extruder, kneader, or roller, or in the presence of a solvent using a reaction vessel equipped with a stirring device.

[0114] As a homogeneous mixing method, a kneading machine, roller, planetary mixer, or similar device can be used to mix the resin composition in a kneading manner within a temperature range of 50 to 100°C to form a homogeneous resin composition. The resulting resin composition can be pulverized and molded into cylindrical tablets, granular powder, or powder-based molded bodies using a molding machine such as a pressing machine. Alternatively, these compositions can be melted onto a surface support and molded into thin sheets with a thickness of 0.05 mm to 10 mm to form a cured resin composition molded body. The resulting molded body is non-sticky at 0 to 20°C, and its fluidity and curability are almost unaffected even after storage at -25 to 0°C for more than one week.

[0115] The resulting molded body can be transferred to a molding machine or a compression molding machine to be molded into a hardened material.

[0116] An organic solvent can be added to the curable resin composition of this embodiment to form a varnish-like composition (hereinafter referred to as varnish). The curable resin composition of this embodiment is optionally dissolved in solvents such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone to form a varnish. This varnish is then impregnated into a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, or paper and dried by heating. The resulting prepreg is then hot-pressed to form a cured product of the curable resin composition of this embodiment. The solvent used in this process is preferably in an amount of 10 to 70% by weight, more preferably 15 to 70% by weight, in the mixture of the curable resin composition and the solvent of this embodiment. Alternatively, if it is a liquid composition, a cured product containing carbon fibers can be obtained directly, for example, by RTM (Resin Transfer Molding).

[0117] Alternatively, the curable composition of this embodiment can also be used as a modifier for film-type compositions. Specifically, it can be used to improve flexibility in the B-stage, etc. This film-type resin composition is obtained by applying the curable resin composition of this embodiment as a varnish onto a release film, removing the solvent under heat, and then performing B-stage curing, thereby obtaining a sheet-like adhesive. This sheet-like adhesive can be used as an interlayer insulating layer in multilayer substrates, etc.

[0118] The curable resin composition of this embodiment can be heated and melted to a low viscosity and impregnated with reinforcing fibers such as glass fibers, carbon fibers, polyester fibers, polyamide fibers, and alumina fibers, thereby obtaining a prepreg. Specific examples include glass fibers such as E-glass cloth, D-glass cloth, S-glass cloth, Q-glass cloth, spherical glass cloth, NE-glass cloth, and T-glass cloth, as well as fibers of inorganic materials other than glass, or poly(p-phenylene terephthalamide) (Kevlar (registered trademark), manufactured by DuPont), fully aromatic polyamides, polyesters; and poly(p-phenylene terephthalamide). Organic fibers such as azole, polyimide, and carbon fiber are used, but are not limited to these. The shape of the substrate is not particularly limited, and examples include woven fabric, nonwoven fabric, roving, and diced felt. Furthermore, known weaving methods include plain weave, caviar weave, and twill weave, and these can be appropriately selected and used depending on the intended use or performance. Additionally, glass fabrics that have undergone defiberization or surface treatment with silane coupling agents are suitable. The thickness of the substrate is not particularly limited, but is preferably around 0.01 to 0.4 mm. Furthermore, the aforementioned varnish can be impregnated with reinforcing fibers and heated and dried to obtain a prepreg.

[0119] The laminate of this embodiment has one or more prepregs. There is no particular limitation as long as the laminate has one or more prepregs; it may have any other layers. The manufacturing method of the laminate can appropriately use generally known methods and is not particularly limited. For example, when forming a metal foil-coated laminate, a multi-stage press, a multi-stage vacuum press, a continuous forming machine, or an autoclave forming machine can be used to stack the prepregs together and heat and pressurize them to obtain the laminate. In this case, the heating temperature is not particularly limited, but is preferably 65 to 300°C, and more preferably 120 to 270°C. Furthermore, the pressure is not particularly limited. If the pressure is too high, it will be difficult to adjust the solids content of the resin in the laminate, resulting in unstable quality. Conversely, if the pressure is too low, air bubbles or poor adhesion between layers will occur. Therefore, 2.0 to 5.0 MPa is preferred, and more preferably 2.5 to 4.0 MPa. The laminate of this embodiment has a layer made of metal foil, and is therefore suitable for use as a metal foil-clad laminate as described later.

[0120] The prepreg is cut into the desired shape and optionally laminated with copper foil, etc. Pressure is applied to the laminate by compression molding, autoclave molding, sheet winding molding, etc., while the curable resin composition is heated and cured, thereby obtaining an electrical and electronic laminate (printed circuit board) or carbon fiber reinforced material.

[0121] The cured product of this embodiment can be used for various applications such as molding materials, adhesives, composite materials, and coatings. The cured product of the curable resin composition described in this embodiment exhibits excellent heat resistance and dielectric properties, and is therefore suitable for use in electrical and electronic components such as sealing materials for semiconductor components, sealing materials for liquid crystal display components, sealing materials for organic EL components, printed circuit boards, and laminates, or in lightweight, high-strength structural composite materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics.

[0122] In this embodiment, the dielectric loss tangent of the hardened material measured at 25°C and a frequency of 10 GHz is preferably less than 0.0016, and more preferably less than 0.0013.

[0123] Example

[0124] Secondly, the present invention will be further described in detail through embodiments. Hereinafter, unless otherwise specified, parts are parts by weight. Furthermore, the present invention is not limited to these embodiments.

[0125] The following describes the various analytical methods used in the examples.

[0126] Gel permeation chromatography (GPC)

[0127] Equipment: ACQUITY APC system (manufactured by Waters Corporation)

[0128] Tubing: Protective tubing: SHODEX GPC KF-601 (2 units), KF-602, KF-602.5, KF-603

[0129] Flow rate: 1.23 ml / min

[0130] Column temperature: 25℃

[0131] Solvent used: THF (tetrahydrofuran)

[0132] Detector: RI (Differential Refraction Detector)

[0133] Maleimide equivalent

[0134] Potentiometric titration apparatus: Automatic titration apparatus COM-1600 (manufactured by HIRANUMA Corporation)

[0135] Apparatus requirements: Comparator electrode RE-201 (manufactured by HIRANUMA Corporation), platinum indicator electrode PT-301 (manufactured by HIRANUMA Corporation).

[0136] Titration method: Weigh 0.5 g of the sample into a beaker and dissolve it in 20 mL of an equal volume mixture of chloroform and isopropanol. Then add 4 mL of a 60 g / L triethylamine toluene solution and react while stirring at room temperature for 30 minutes. After the reaction is complete, add another 30 mL of an equal volume mixture of chloroform and isopropanol and titrate using a potentiometric titration apparatus to obtain the target maleimide equivalent.

[0137] [Example 1]

[0138] In a flask equipped with a thermometer, cooling pipe, and stirrer, 30.0 parts of toluene, 11.2 parts of n-methylpyrrolidone, 4.24 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), and 0.08 parts of methanesulfonic acid were added to form a homogeneous solution. Then, 22.0 parts of a styrene / maleic anhydride copolymer (acid value: 50, Mn: 2,278, Mw: 3,903) were added at 120°C over 5 hours, and the reaction was continued at 120°C for 16 hours. After cooling, 3.96 parts of maleic anhydride were added, and the reaction was continued at 130°C under reflux for 8 hours. After cooling, the reaction solution was diluted with 200 parts of toluene, and the organic layer was washed five times with 100 parts of warm water at 80°C. The solvent was removed by distillation under heating and reduced pressure to obtain the target compound (M-1) (Mn: 1641, Mw: 3431, maleimide equivalent: 1180 g / eq) as a brown solid resin. The GPC chromatogram of the obtained compound is shown in [image / image / etc.]. Figure 1 The proportion of component (c) obtained from the peak area ratio is 14.6%. Based on the acid value and molecular weight of the styrene / maleic anhydride copolymer of the raw material, m is calculated to be 27.6 and n to be 1.3.

[0139] [Example 2]

[0140] 30.0 parts of toluene, 10 parts of n-methylpyrrolidone, 6.35 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), and 0.13 parts of methanesulfonic acid were added to a flask equipped with a thermometer, cooling pipe, and stirrer to confirm a homogeneous solution. 19.8 parts of a styrene / maleic anhydride copolymer (acid value: 85, Mn: 1,979, Mw: 3,088) were added at 120°C for 5 hours, and the reaction was continued at 120°C for 10 hours. After cooling, 8.87 parts of maleic anhydride were added, and the reaction was continued at 130°C under reflux for 6 hours. After cooling, the reaction solution was diluted with 300 parts of toluene, and the organic layer was washed five times with 100 parts of 10wt% brine. The solvent was removed by distillation under heating and reduced pressure to obtain the target compound (M-2) (Mn: 1542, Mw: 3560) as a brown solid resin. The GPC chromatogram of the obtained compound is shown in [image missing]. Figure 2 The proportion of component (c) obtained from the peak area ratio is 16.6%. Based on the acid value and molecular weight of the styrene / maleic anhydride copolymer of the raw material, m is calculated to be 26.7 and n to be 2.3.

[0141] [Example 3]

[0142] In a flask equipped with a thermometer, cooling pipe, and stirrer, 24.5 parts of toluene, 8.17 parts of n-methylpyrrolidone, 5.30 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), 0.21 parts of methanesulfonic acid, and 16.5 parts of styrene / maleic anhydride copolymer (acid value: 85, Mn: 1,979, Mw: 3,088) were added, and the mixture was reacted at 120°C for 15 hours. After cooling, 13.6 parts of toluene, 4.54 parts of n-methylpyrrolidone, and 3.06 parts of maleic anhydride were added, and the reaction was continued at 120°C under reflux for 8 hours. After cooling, the reaction solution was diluted with 235 parts of toluene, and the organic layer was washed three times with 100 parts of 10wt% saline solution and three times with 100 parts of 80°C warm water. The solvent was removed by distillation under heating and reduced pressure to obtain the target compound (M-3) (Mn: 1555, Mw: 3625, maleimide equivalent: 920 g / eq) as a brown solid resin. The GPC chromatogram of the obtained compound is shown in [image / image / etc.]. Figure 3 The proportion of component (c) obtained from the peak area ratio is 16.4%. Based on the acid value and molecular weight of the styrene / maleic anhydride copolymer of the raw material, m is calculated to be 26.7 and n to be 2.3.

[0143] [Example 4]

[0144] In a flask equipped with a thermometer, cooling pipe, and stirrer, 24.5 parts of toluene, 8.17 parts of n-methylpyrrolidone, 5.30 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), and 0.21 parts of methanesulfonic acid were added to confirm a homogeneous solution. Then, 16.5 parts of a styrene / maleic anhydride copolymer (acid value: 85, Mn: 1,979, Mw: 3,088) were added at 120°C over 5 hours, and the reaction was continued at 120°C for 10 hours. After cooling, 13.6 parts of toluene, 4.54 parts of n-methylpyrrolidone, and 3.06 parts of maleic anhydride were added, and the reaction was continued at 122°C under reflux for 8 hours. After cooling, the reaction solution was diluted with 235 parts of toluene, and the organic layer was washed three times with 100 parts of 10wt% saline solution and three times with warm water at 80°C. The solvent was removed by distillation under heating and reduced pressure to obtain the target compound (M-4) (Mn: 1340, Mw: 2858, maleimide equivalent: 780 g / eq) as a brown solid resin. The GPC chromatogram of the obtained compound is shown in [image / image / etc.]. Figure 4The proportion of component (c) obtained from the peak area ratio is 21.5%. Based on the acid value and molecular weight of the styrene / maleic anhydride copolymer of the raw material, m is calculated to be 26.7 and n to be 2.3.

[0145] [Example 5]

[0146] In a flask equipped with a thermometer, cooling pipe, and stirrer, 20.0 parts of toluene, 6.66 parts of n-methylpyrrolidone, 5.30 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), 0.21 parts of methanesulfonic acid, and 16.5 parts of styrene / maleic anhydride copolymer (acid value: 85, Mn: 1,979, Mw: 3,088) were added, and the mixture was reacted at 120°C for 32 hours. After cooling, 18.2 parts of toluene, 6.06 parts of n-methylpyrrolidone, and 3.06 parts of maleic anhydride were added, and the mixture was further reacted at 120°C under reflux for 8 hours. After cooling, the reaction solution was diluted with 235 parts of toluene, and the organic layer was washed three times with 100 parts of 10wt% saline solution and three times with 100 parts of 80°C warm water. The solvent was removed by distillation under heating and reduced pressure to obtain the target compound (M-5) (Mn: 1812, Mw: 5985, maleimide equivalent: 940 g / eq) as a brown solid resin. The GPC chromatogram of the obtained compound is shown in [image / image / etc.]. Figure 5 The proportion of component (c) obtained from the peak area ratio is 12.6%. Based on the acid value and molecular weight of the styrene / maleic anhydride copolymer of the raw material, m is calculated to be 26.7 and n to be 2.3.

[0147] [Example 6]

[0148] In a flask equipped with a thermometer, cooling pipe, and stirrer, 60.0 parts of toluene, 20 parts of n-methylpyrrolidone, 8.47 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), and 0.17 parts of methanesulfonic acid were added to confirm a homogeneous solution. Then, 20.0 parts of a styrene / maleic anhydride copolymer (acid value: 140, Mn: 1,978, Mw: 3,107) were added at 120°C over 5 hours, and the reaction was continued at 120°C for 10 hours. After cooling, 4.00 parts of maleic anhydride were added, and the reaction was continued at 120°C under reflux for 13 hours. After cooling, the reaction solution was diluted with 100 parts of toluene, and the organic layer was washed five times with 100 parts of warm water at 80°C. The solvent was removed by distillation under heating and reduced pressure to obtain the target compound (M-6) (Mn: 1173, Mw: 2554, maleimide equivalent: 650 g / eq) as a brown solid resin. The GPC chromatogram of the obtained compound is shown in [image / image / etc.]. Figure 6 The proportion of component (c) obtained from the peak area ratio is 28.8%. Based on the acid value and molecular weight of the styrene / maleic anhydride copolymer of the raw material, m is calculated to be 25.3 and n to be 3.7.

[0149] [Example 7]

[0150] In a flask equipped with a thermometer, cooling pipe, and stirrer, 30.1 parts of toluene, 10.0 parts of n-methylpyrrolidone, 6.35 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), and 0.25 parts of methanesulfonic acid were added to confirm a homogeneous solution. Then, 19.8 parts of a styrene / maleic anhydride copolymer (acid value: 85, Mn: 1,979, Mw: 3,088) were added and reacted at 120°C for 10 hours after the addition process, which lasted for 5 hours. After cooling, 15.0 parts of toluene, 5.0 parts of n-methylpyrrolidone, and 3.56 parts of maleic anhydride were added, and the reaction was continued at 120°C under reflux for 8 hours. After cooling, the reaction solution was diluted with 285 parts of toluene, and the organic layer was washed 6 times with 100 parts of 10wt% saline solution and 3 times with 100 parts of 80°C warm water. The solvent was removed by distillation under heating and reduced pressure to obtain the target compound (M-7) (Mn:1491, Mw:3402) as a brown solid resin. The GPC chromatogram of the obtained compound is shown in [image missing]. Figure 7 The proportion of component (c) obtained from the peak area ratio is 17.7%. Based on the acid value and molecular weight of the styrene / maleic anhydride copolymer of the raw material, m is calculated to be 26.7 and n to be 2.3.

[0151] [Comparative Example 1]

[0152] 75.0 parts of toluene, 25.0 parts of n-methylpyrrolidone, 8.47 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), 0.17 parts of methanesulfonic acid, and 18.7 parts of styrene / maleic anhydride copolymer (acid value: 60, Mn: 6,686, Mw: 11,295) were added to a flask equipped with a thermometer, cooling pipe, and stirrer, and the mixture was reacted at 120°C for 2 hours. After cooling, 5.88 parts of maleic anhydride were added, and the reaction was continued at 120°C under reflux for 6 hours. After cooling, the reaction solution was diluted with 50 parts of toluene, and the organic layer was washed five times with 100 parts of warm water at 80°C. The solvent was removed by distillation under heating and reduced pressure to obtain the target compound (M-8) as a brown solid resin. The GPC diagram of the obtained compound is shown in [Figure number missing]. Figure 8 The proportion of component (c) obtained from the peak area ratio is 37.7%. Based on the acid value and molecular weight of the styrene / maleic anhydride copolymer of the raw material, m is calculated to be 92.4 and n to be 5.4.

[0153] [Comparative Example 2]

[0154] 75.0 parts of toluene, 25.0 parts of n-methylpyrrolidone, 14.12 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), 0.28 parts of methanesulfonic acid, and 23.4 parts of styrene / maleic anhydride copolymer (acid value: 120, Mn: 5,984, Mw: 14,768) were added to a flask equipped with a thermometer, cooling pipe, and stirrer, and the mixture was reacted at 120°C for 3 hours. After cooling, 9.81 parts of maleic anhydride were added, and the reaction was continued at 120°C under reflux for 8 hours. After cooling, the reaction solution was diluted with 100 parts of toluene, and the organic layer was washed 5 times with 100 parts of warm water at 80°C. The solvent was removed by distillation under heating and reduced pressure to obtain the target compound (M-9) (Mn: 1210, Mw: 8644) as a brown solid resin. The GPC diagram of the obtained compound is shown in [Figure / Diagram would be inserted here]. Figure 9 The proportion of component (c) obtained from the peak area ratio is 37.8%. Based on the acid value and molecular weight of the styrene / maleic anhydride copolymer of the raw material, m is calculated to be 116.2 and n to be 14.4.

[0155] [Comparative Example 3]

[0156] In a flask equipped with a thermometer, cooling pipe, and stirrer, 75.0 parts of toluene, 25.0 parts of n-methylpyrrolidone, 5.65 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), 0.11 parts of methanesulfonic acid, and 18.7 parts of styrene / maleic anhydride copolymer (acid value: 60, Mn: 6,686, Mw: 11,295) were added, and the mixture was reacted at 120°C for 2 hours. After cooling, 2.94 parts of maleic anhydride were added, and the reaction was continued at 130°C under reflux for 17 hours. After cooling, the reaction solution was diluted with 50 parts of toluene, and an attempt was made to wash the organic layer with 100 parts of warm water at 80°C, but the organic layer and the aqueous layer did not separate.

[0157] Solvent solubility and storage stability tests

[0158] The maleimide resin mixtures obtained in Examples 1 to 7 and Comparative Examples 1 to 2, and the maleimide resin (Mn: 2126, Mw: 11527) described in Example 12 of Japanese Patent No. 7208705 were added to toluene at a ratio of 60% by weight of resin and stirred. As a result, the maleimide resin mixtures obtained in Examples 1 to 7 and Comparative Examples 1 to 2 dissolved in toluene, but the maleimide resin described in Example 12 of Japanese Patent No. 7208705 did not dissolve in toluene.

[0159] Next, 1 g of a solution dissolved in toluene was added to a 6 cc screw flask, with the resin content of the maleimide resin mixtures obtained in Examples 1 to 7 and Comparative Examples 1 to 2 reaching 60% by weight. The flask was capped and sealed, and then left to stand in a refrigerator at 5.0 to 10.0°C for 24 hours. The presence or absence of crystallization was then visually confirmed. No crystallization was marked as 0, and crystallization was marked as ×. The results are recorded in Table 1.

[0160] The maleimide resin described in Example 12 of Japanese Patent No. 7208705 was not soluble in toluene under the above conditions. Therefore, the amount of toluene was increased to confirm solubility. It was found to be insoluble in toluene when the resin content was between 60 and 20% by weight, but was confirmed to be soluble in toluene when it reached 10% by weight. Therefore, 1 g of a solution dissolved in toluene to achieve 10% by weight of the maleimide resin described in Example 12 of Japanese Patent No. 7208705 was added to a 6cc screw-top flask. The flask was capped and left to stand at room temperature for 24 hours in a sealed state. The presence or absence of crystal precipitation was then visually confirmed. Precipitation was confirmed.

[0161] [Table 1]

[0162]

[0163] The results in Table 1 confirm that the maleimide resin mixtures obtained in Examples 1 to 7 have excellent solvent solubility and storage stability in solution state (varnish).

[0164] [Examples 8 to 11, Comparative Examples 4 to 6]

[0165] A 250μm thick frame-shaped buffer paper with a central cut of 100mm × 50mm was placed on the first copper foil. 5.0g of the sample, prepared according to the proportions in Table 2, was placed in the center of the frame. The buffer paper and sample were then sandwiched between the first and second copper foils, which were positioned opposite the first copper foil. The mixture was then shaped using a vacuum heating press and cured at 220°C for 2 hours. Subsequently, the first and second copper foils were etched with ferric chloride (III) to obtain the cured film. The dielectric loss tangent of the cured film was measured using the method described below and recorded in Table 2.

[0166] <Dielectric Loss Tangent Test>

[0167] The experiment was conducted at 25°C using a 10GHz cavity resonator manufactured by AET Corporation, employing the cavity resonator perturbation method. The sample dimensions were 2.5 mm wide × 100 mm long and 0.20 mm thick.

[0168] [Table 2]

[0169]

[0170] • OPE-2St-2200 (a polyphenylene ether compound with a styrene structure, manufactured by Mitsubishi Gas Chemical Company)

[0171] ·2E4MZ: 2-Ethyl-4-methylimidazolium (hardening accelerator, manufactured by Shikoku Chemical Co., Ltd.)

[0172] The results in Table 2 confirm that Examples 8 to 11 have excellent low dielectric loss tangent.

[0173] The attenuation rate of a signal flowing through the dielectric material that makes up a printed circuit board is proportional to the dielectric loss tangent. Signal attenuation directly generates heat and causes a temperature rise; therefore, low dielectric loss tangent is crucial for printed circuit board materials.

[0174] [Example 8, Comparative Example 6]

[0175] The glass transition temperature (Tg) of Example 8 and Comparative Example 6, prepared according to the ratios described in Table 2, was determined under the following conditions. The results are shown in Table 3.

[0176] <Glass transition temperature (Tg)>

[0177] Differential scanning calorimeter (DSC): DSC6220 (manufactured by SII NanoTechnology)

[0178] Measurement temperature range: 30 to 350℃

[0179] Heating rate: 10℃ / minute

[0180] Environment: Nitrogen (30 mL / min)

[0181] Sample size: 5mg

[0182] [Table 3]

[0183] Example 8 Comparative Example 6 Tg 261.7℃ 240.0℃

[0184] [Maleimide Resin M-10]

[0185] In a flask equipped with a thermometer, cooling pipe, and stirrer, 26.9 parts of toluene, 8.95 parts of n-methylpyrrolidone, 17.30 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline), and 0.69 parts of methanesulfonic acid were added to confirm a homogeneous solution. Then, 36.4 parts of a styrene / maleic anhydride copolymer (acid value: 150, Mn: 2,454, Mw: 4,997) were added, and the reaction was carried out at 115±2℃ for 15 hours. After cooling, 13.4 parts of toluene, 9.0 parts of n-methylpyrrolidone, and 14.4 parts of maleic anhydride were added, and the reaction was continued at 120℃ under reflux for 6 hours. After cooling, the reaction solution was diluted with 645 parts of toluene, and the organic layer was washed four times with 245 parts of 10wt% saline solution and three times with 245 parts of warm water at 80℃. The solvent was removed by distillation under heating and reduced pressure, and the resulting solution was used to obtain the target compound (M-10) (Mn: 2281, Mw: 54801, maleimide equivalent: 810 g / eq). The GPC chromatogram of the obtained compound is shown in [image / image / etc.]. Figure 10 The proportion of component (c) obtained from the peak area ratio is 17.2%. Based on the acid value and molecular weight of the styrene / maleic anhydride copolymer of the raw material, m is calculated to be 41.5 and n to be 6.7.

[0186] [Examples 12 to 14]

[0187] A 250μm thick buffer paper with a centrally cut 150mm × 150mm section was placed on a first copper foil. 5.0g of the sample prepared according to the proportions in Table 4 was placed in the center of the buffer paper within the buffer paper's frame. The sample and buffer paper were then sandwiched between a second copper foil (opposite to the first copper foil) and the first copper foil, and shaped using a vacuum heating press. The mixture was then cured at 220°C for 2 hours. Subsequently, the first and second copper foils were etched with ferric chloride (III) to obtain the cured film. The dielectric loss tangent and glass transition temperature (Tg) of the cured film were measured using the methods described below and recorded in Table 4.

[0188] <Dielectric Loss Tangent Test>

[0189] The experiment was conducted at 25°C using a 10GHz cavity resonator manufactured by AET Corporation, employing the cavity resonator perturbation method. The sample dimensions were 2.5 mm wide × 100 mm long and 0.20 mm thick.

[0190] <Glass transition temperature (Tg)>

[0191] Dynamic viscoelasticity measuring device: DMA Q800 (TA instruments)

[0192] Measurement temperature range: 30 to 350℃

[0193] Heating rate: 2℃ / minute

[0194] Sample quantity: 5mm width × 40mm length × 0.5mm thickness

[0195] Judgment Criterion: The peak point of tanδ is taken as Tg

[0196] [Table 4]

[0197]

[0198] • SA-9000-111 (a polyphenylene ether compound with a methacrylate structure, manufactured by Sabic)

[0199] • OPE-2St-2200 (a polyphenylene ether compound with a styrene structure, manufactured by Mitsubishi Gas Chemical Co., Ltd.)

[0200] • S-1 (The solvent of the styrene resin obtained by the method described in Example 1 of Japanese Patent No. 7353538 is removed by heating and reducing pressure)

[0201] •TAIC (Trylyl isocyanurate, manufactured by Mitsubishi Chemical Corporation)

[0202] • Septon 2104 (Styrene / Ethylene / Propylene / Styrene / Rubber, manufactured by Kuraray Inc.)

[0203] • DCP (Diisopropylbenzene peroxide, manufactured by KAYAKU NOURYON Co., Ltd.)

[0204] The results in Table 4 confirm that the dielectric loss tangent of Examples 12 to 14 did not reach 0.0016, indicating that they have excellent dielectric properties.

[0205] The attenuation rate of a signal flowing through the dielectric material that makes up a printed circuit board is proportional to the dielectric loss tangent. Signal attenuation directly generates heat and causes a temperature rise; therefore, low dielectric loss tangent is crucial for printed circuit board materials.

[0206] This application claims priority based on Japanese Patent Application No. 2023-046176 filed on March 23, 2023 and Japanese Patent Application No. 2023-217507 filed on December 25, 2023.

[0207] [Industrial applicability]

[0208] The curable resin composition and its cured products of the present invention can be used in insulating materials for electrical and electronic components (such as high-reliability semiconductor sealing materials), laminates (such as printed circuit boards, BGA substrates, and build-up substrates), adhesives (such as conductive adhesives), or various composite materials, primarily CFRP, for applications such as coatings and 3D printing.

Claims

1. A maleimide resin mixture composed of a maleimide resin having repeating units of the following formulas (a) and (b), and bis(3-ethyl-5-methyl-4-maleimidophenyl)methane represented by the following formula (c). In the total amount of the maleimide resin mixture, the content of bis(3-ethyl-5-methyl-4-maleimidophenyl)methane represented by the aforementioned formula (c) is 5.0 to 30.0 area% in terms of GPC area percentage. In the above formulas, m is the average value of the number of repetitions, 0 < m < 200, n is the average value of the number of repetitions, 0 < n < 100, and (a) and (b) are bonded by * respectively, and the repeating positions can be random.

2. The maleimide resin mixture according to claim 1, obtained by reacting a styrene / maleic anhydride copolymer, 4,4'-methylenebis(2-ethyl-6-methylaniline), and maleic anhydride.

3. The maleimide resin mixture according to claim 2, wherein the weight average molecular weight of the aforementioned styrene / maleic anhydride copolymer is 900 or more and less than 10,000.

4. A curable resin composition containing the maleimide resin mixture according to any one of claims 1 to 3.

5. The curable resin composition according to claim 4, which further contains at least one selected from the group consisting of maleimide resins other than the aforementioned maleimide resin mixture, polyphenylene ether compounds, compounds having ethylenic unsaturated bonds, cyanate ester resins, polybutadiene and its modified products, polystyrene and its modified products, polyethylene and its modified products.

6. The curable resin composition according to claim 4, further containing a curing accelerator.

7. The curable resin composition according to claim 4, for use in a printed circuit board.

8. A varnish composed of the maleimide resin mixture according to any one of claims 1 to 3 and an organic solvent.

9. A varnish composed of the curable resin composition according to claim 4 and an organic solvent.

10. A cured product obtained by curing the maleimide resin mixture according to any one of claims 1 to 3.

11. A cured product obtained by curing the curable resin composition according to claim 4.

12. The cured product according to claim 11, having a dielectric loss tangent of less than 0.0016 at a frequency of 10 GHz measured at 25°C.

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