Photo-curable maleimide resin composition

Abstract

To provide a photocurable maleimide resin composition which has excellent dielectric characteristics and excellent storage stability and adhesive force.SOLUTION: A photocurable maleimide resin composition contains (A) a maleimide compound having one or more saturated or unsaturated divalent aliphatic hydrocarbon groups having 6 to 200 carbon atoms in one molecule, (B) a polymerization initiator, (C) a photocuring initiator, and (D) an adhesive auxiliary.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a photocurable maleimide resin composition. [Background technology]

[0002] Photocurable resins (photosensitive resins), typified by UV-curable resins, are already being used in many places. Photocurable resins can be broadly divided into two types: those that cure through the radical polymerization of unsaturated double bonds such as acrylic groups, and those that cure through cationic polymerization such as epoxy groups. Generally, however, they often have functional groups that contain heteroatoms such as oxygen atoms, and the values ​​of the relative dielectric constant and dielectric loss tangent of the cured product are large.

[0003] In recent years, the next-generation communication system known as 5G has been developed, aiming to realize faster, larger capacity, and lower latency communications than ever before. To achieve this, materials for high frequency bands are required, and reducing transmission loss as a noise countermeasure is essential. For this reason, there is a demand for the development of insulating materials with excellent dielectric properties (low dielectric constant and low dielectric tangent) for use in binder resins for circuit boards, materials for laminating wiring for semiconductors, adhesives, etc.

[0004] As mentioned above, many photocurable resins have poor dielectric properties (high dielectric constant and high dielectric tangent). However, a photocurable material with excellent dielectric properties has been reported by using a special colored but transparent maleimide resin (Patent Document 1). However, there remain issues with curing, such as insufficient deep curing.

[0005] On the other hand, reports have been made to solve the problem of curability (Patent Documents 2 to 5). Proposals have been made to use a specific photocuring initiator or to use a maleimide resin with a high reactivity and small functional group equivalent in combination, but it is already known that maleimide resins undergo gelation when exposed to light for a long period of time, and it has also been found that the compositions in these reports have poor storage stability and partial reaction proceeds even when stored in a dark place for a long period of time. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] WO 2018 / 56466 [Patent Document 2] JP 2020-33470 A [Patent Document 3] JP 2020-33472 A [Patent Document 4] WO 2020 / 45489 [Patent Document 5] International Publication No. 2020 / 262577 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, an object of the present invention is to provide a photocurable maleimide resin composition which has excellent dielectric properties, storage stability and adhesive strength. [Means for solving the problem]

[0008] Means of Solving the Problems The present inventors have conducted intensive research to solve the above problems and have found that the following photocurable maleimide resin composition can achieve the above object, thereby completing the present invention.

[0009] <1> (A) a maleimide compound having one or more saturated or unsaturated divalent aliphatic hydrocarbon groups having 6 to 200 carbon atoms per molecule; (B) a polymerization inhibitor, (C) Photocuring initiator and (D) Adhesive assistant A photocurable maleimide resin composition comprising: <2> The maleimide compound of component (A) is a bismaleimide compound having two maleimide groups in one molecule. <1> 2. The photocurable maleimide resin composition according to claim 1 . <3> The maleimide compound of component (A) has one or more hydrocarbon groups derived from a dimer acid skeleton in each molecule. <1> or <2> 2. The photocurable maleimide resin composition according to claim 1 . <4> The maleimide compound of component (A) is a maleimide compound represented by the following formula (1) and has at least one dimer acid skeleton in one molecule: <1> ~ <3> 13. The photocurable maleimide resin composition according to claim 12. [ka] (In formula (1), A is independently a tetravalent organic group having a cyclic structure, B is independently a divalent hydrocarbon group having 6 to 200 carbon atoms, and at least one of them is a dimer acid skeleton. n is 0 to 100.) <5> In formula (1), A is any of the tetravalent organic groups represented by the following structural formulas: <4> 2. The photocurable maleimide resin composition according to claim 1 . [ka] (The bond not bonded to a substituent in the above structural formula is bonded to the carbonyl carbon that forms a cyclic imide structure in formula (1).) <6> The content of the polymerization inhibitor in the component (B) is 0.01 to 0.50 parts by mass per 100 parts by mass of the component (A). <1> ~ <5> 13. The photocurable maleimide resin composition according to claim 12. <7> The content of the photocuring initiator of the component (C) is 0.1 to 5.0 parts by mass per 100 parts by mass of the component (A). <1> ~ <6> 13. The photocurable maleimide resin composition according to claim 12. <8> The adhesive aid of component (D) has a functional group capable of reacting with the maleimide group in component (A). <1> ~ <7> 13. The photocurable maleimide resin composition according to claim 12. Effect of the Invention

[0010] The photocurable maleimide resin composition of the present invention is a resin composition having excellent dielectric properties (low relative dielectric constant and low dielectric tangent), excellent storage stability and adhesive strength. Therefore, the photocurable maleimide resin composition of the present invention is useful, for example, as a protective film for an insulating layer between wiring layers and a solder resist, an adhesive for a glass substrate, etc. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will now be described in more detail.

[0012] [(A) Maleimide compound having one or more saturated or unsaturated divalent aliphatic hydrocarbon groups having 6 to 200 carbon atoms per molecule] The component (A) used in the present invention is a specific maleimide compound, and has in one molecule at least one saturated or unsaturated divalent aliphatic hydrocarbon group having 6 to 200 carbon atoms. By having an aliphatic hydrocarbon group, the cured product of the resin composition containing this can have excellent dielectric properties.

[0013] From the viewpoints of availability of raw materials and stability of synthesis, the maleimide compound of the component (A) is preferably a bismaleimide compound having two maleimide groups in one molecule.

[0014] The maleimide compound of the component (A) more preferably has a hydrocarbon group derived from a dimer acid skeleton, among divalent aliphatic hydrocarbon groups.

[0015] The dimer acid referred to here is a liquid dibasic acid mainly composed of a dicarboxylic acid having 36 carbon atoms, which is produced by dimerization of unsaturated fatty acids having 18 carbon atoms, which are derived from natural products such as vegetable oils and fats. Dimer acids do not have a single skeleton, but have multiple structures, and there are several types of isomers. Representative dimer acids are classified as linear (a), monocyclic (b), aromatic (c), and polycyclic (d). In this specification, the dimer acid skeleton refers to a group derived from a dimer diamine having a structure in which the carboxy group of such a dimer acid is substituted with a primary aminomethyl group. That is, the (A) component preferably has a dimer acid skeleton in which two carboxy groups are substituted with methylene groups in each of the dimer acids shown in (a) to (d) below. Furthermore, when the maleimide compound of component (A) has a hydrocarbon group derived from a dimer acid skeleton, the hydrocarbon group derived from the dimer acid skeleton preferably has a structure in which the carbon-carbon double bond in the hydrocarbon group derived from the dimer acid skeleton is reduced by a hydrogenation reaction, from the viewpoint of the heat resistance and reliability of the cured product. [ka]

[0016] The maleimide compound of component (A) is preferably a maleimide compound represented by the following formula (1) having at least one dimer acid skeleton in one molecule. The use of this maleimide compound represented by the following formula (1) results in a composition that is excellent in dielectric properties both before and after curing, has strong adhesion to metals, and is highly reliable. [ka] (In formula (1), A is independently a tetravalent organic group having a cyclic structure, B is independently a divalent hydrocarbon group having 6 to 200 carbon atoms, and at least one of them is a dimer acid skeleton. n is 0 to 100.)

[0017] In the formula (1), A independently represents a tetravalent organic group having a cyclic structure, and is preferably any of the tetravalent organic groups represented by the following structural formulas. [ka]

[0018] In addition, in the formula (1), B is independently a divalent hydrocarbon group having 6 to 200 carbon atoms, preferably 8 to 100, and more preferably 10 to 50. Among them, it is preferable that the divalent hydrocarbon group is a branched divalent hydrocarbon group in which one or more hydrogen atoms are substituted with an alkyl or alkenyl group having 1 to 200 carbon atoms, preferably 1 to 100, and more preferably 1 to 50 carbon atoms. The branched divalent hydrocarbon group may be either a saturated aliphatic hydrocarbon group or an unsaturated hydrocarbon group. Specific examples of the branched divalent hydrocarbon group include divalent hydrocarbon groups derived from diamines at both ends, called dimer diamines. Note that dimer diamines are compounds derived from dimers (dimer acids) of unsaturated fatty acids such as oleic acid, and therefore B is particularly preferably a group in which the two carboxy groups in each of the dimer acids (a) to (d) above are each substituted with a methylene group.

[0019] In the formula (1), n ​​is an integer of 0 to 100, preferably 0 to 60, and more preferably 0 to 50. If n is too large, the solubility and flowability may decrease, leading to the risk of poor moldability.

[0020] The number average molecular weight of the maleimide compound of component (A) is not particularly limited, but from the viewpoint of the handleability of the composition, it is preferably from 800 to 50,000, and more preferably from 900 to 30,000. Moreover, component (A) may be used alone or in combination of two or more kinds. The number average molecular weight referred to in this specification refers to the number average molecular weight measured by gel permeation chromatography (GPC) under the following conditions using polystyrene as a standard substance.

[0021] [Measurement conditions] Developing solvent: Tetrahydrofuran (THF) Flow rate: 0.35mL / min Detector: Refractive index detector (RI) Column: TSK Guardcolumn SuperH-L TSKgel SuperHZ4000(4.6mmI.D.×15cm×1) TSKgel SuperHZ3000(4.6mmI.D.×15cm×1) TSKgel SuperHZ2000(4.6mmI.D.×15cm×2) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 5 μL (0.2% by mass in THF solution)

[0022] [(B) Polymerization inhibitor] The component (B) used in the present invention is a polymerization inhibitor. The polymerization inhibitor is blended to improve the storage stability of the photocurable resin composition of the present invention, and is not particularly limited as long as it can improve the storage stability.

[0023] Examples of the polymerization inhibitor include commonly used ones such as catechol, resorcinol, and 1,4-hydroquinone, as well as 2-methylcatechol, 3-methylcatechol, 4-methylcatechol, 2-ethylcatechol, 3-ethylcatechol, 4-ethylcatechol, 2-propylcatechol, 3-propylcatechol, 4-propylcatechol, 2-n-butylcatechol, 3-n-butylcatechol, 4-n-butylcatechol, 2-tert-butylcatechol, and 3-tert-butylcatechol. alkyl catechol compounds such as catechol, 4-tert-butylcatechol, and 3,5-di-tert-butylcatechol; alkyl resorcinol compounds such as 2-methylresorcinol, 4-methylresorcinol, 2-ethylresorcinol, 4-ethylresorcinol, 2-propylresorcinol, 4-propylresorcinol, 2-n-butylresorcinol, 4-n-butylresorcinol, 2-tert-butylresorcinol, and 4-tert-butylresorcinol; methylhydroquinol alkylhydroquinone compounds such as tributylphosphine, trioctylphosphine, tricyclohexylphosphine, triphenylphosphine; phosphine oxide compounds such as trioctylphosphine oxide, triphenylphosphine oxide; phosphite compounds such as triphenylphosphine, tris(nonylphenyl)phosphite; 2,2,6,6-tetramethylpiperidine-1 hindered amine compounds such as 1,4-dihydroxy-2-naphthalenesulfonate ammonium and 4-methoxy-1-naphthol; naphthoquinone compounds such as 1,4-naphthoquinone, 2-hydroxy-1,4-naphthoquinone and anthrone; and phenolic antioxidants such as pyrogallol, phloroglucin and 4,4'-butylidene-bis(6-tert-butyl-m-cresol).

[0024] The content of the polymerization inhibitor in the component (B) is preferably 0.01 to 0.50 parts by mass, more preferably 0.02 to 0.45 parts by mass, and even more preferably 0.03 to 0.40 parts by mass, per 100 parts by mass of the component (A). Furthermore, when the composition of the present invention contains a photocurable resin having a reactive group capable of reacting with a maleimide group other than the component (A) described below, the content of the component (B) is preferably 0.01 to 0.70 parts by mass, more preferably 0.02 to 0.60 parts by mass, and even more preferably 0.03 to 0.50 parts by mass relative to 100 parts by mass of the sum of the component (A) and the photocurable resin having a reactive group capable of reacting with a maleimide group other than the component (A) (hereinafter, both components may be collectively referred to simply as the "photocurable resin component"). If the amount of the (B) component is less than 0.01 parts by mass per 100 parts by mass of the (A) component, the polymerization inhibitory effect may be weakened. If the amount is more than 0.50 parts by mass, the effect will plateau and not only will little improvement in storage stability be expected, but curing properties may also be affected. The component (B) may be used alone or in combination of two or more.

[0025] [(C) Photocuring initiator] The photocuring initiator (C) is added to promote the crosslinking reaction of the maleimide compound (A) and the crosslinking reaction with a reactive group capable of reacting with the maleimide group in component (A). A photosensitizer such as an amine compound, a urea compound, a sulfur-containing compound, a phosphorus-containing compound, or a nitrile compound may also be used in combination.

[0026] The photocuring initiator is not particularly limited as long as it initiates a reaction by light. Examples of the photocuring initiator include aromatic ketones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropanone-1, 2,4-diethylthioxanthone, 2-ethylanthraquinone, and phenanthrenequinone; benzyl dimethyl ketal; Benzyl derivatives; 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-phenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, 2,4-di(p-methoxyphenyl)-5-phenylimidazole 2,4,5-triarylimidazole dimers such as 2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer; acridine derivatives such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; bisacylphosphine oxides such as bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide. Sides include alkylphenone compounds such as 1-hydroxy-cyclohexyl-phenyl-ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and benzophenone compounds.

[0027] The content of the photocuring initiator, component (C), relative to 100 parts by mass of component (A) is preferably 0.1 to 5.0 parts by mass, more preferably 0.2 to 4.5 parts by mass, and even more preferably 0.5 to 4.0 parts by mass. Furthermore, when the composition of the present invention contains a photocurable resin having a reactive group capable of reacting with a maleimide group other than the below-described component (A), the content of the component (C) is preferably 0.1 to 7.0 parts by mass, more preferably 0.2 to 6.0 parts by mass, and even more preferably 0.5 to 5.0 parts by mass, relative to 100 parts by mass of the photocurable resin component. If the amount of component (C) is less than 0.1 parts by mass per 100 parts by mass of component (A), the photocuring process may be slow. If the amount is more than 5.0 parts by mass, the product may lack storage stability even when a polymerization inhibitor is added. The component (C) may be used alone or in combination of two or more types.

[0028] [(D) Adhesive assistant] The adhesive aid (D) is blended to improve the adhesive strength of the photocurable resin composition. The maleimide compound (A) has strong adhesive strength to metals, but has issues with adhesive strength to some materials such as glass, and the adhesive aid (D) has the effect of improving adhesive strength to these adherends.

[0029] Examples of the adhesion promoter include a silane coupling agent, a triazole-based compound, and a tetrazole-based compound.

[0030] The adhesive aid may be of any type, but it is preferable that it has a functional group capable of reacting with the maleimide group in component (A). Examples of the functional group capable of reacting with the maleimide group include maleimide groups, epoxy groups, (meth)acrylic groups, vinyl groups, allyl groups, phenolic hydroxyl groups, and amino groups. Among these, those having either a maleimide group or a (meth)acrylic group, which have excellent photocuring properties, are preferable.

[0031] Examples of silane coupling agents include epoxy group-containing alkoxysilanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-methacryloxypropylmethyldiethoxysilane; Examples of alkoxysilanes include (meth)acrylic group-containing alkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane; alkenyl group-containing alkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane; and amino group-containing alkoxysilanes such as N-2-(aminoethyl)3-aminopropyltrimethoxysilane, N-2-(aminoethyl)3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane. Examples of triazole compounds include 1,2,3-triazole, 1,2,4-triazole, benzotriazole, and N-trimethylsilyl-benzotriazole. Examples of the tetrazole compounds include 1H-tetrazole, 5-amino-1H-tetrazole, 5-phenyl-1H-tetrazole, and 1-phenyl-5-mercapto-1H-tetrazole.

[0032] The content of the adhesive aid of the component (D) is preferably 0.01 to 10.0 parts by mass, more preferably 0.05 to 8.0 parts by mass, and even more preferably 0.1 to 5.0 parts by mass, per 100 parts by mass of the component (A). Furthermore, when the composition of the present invention contains a photocurable resin having a reactive group capable of reacting with a maleimide group other than the component (A) described below, the content of the component (D) is preferably 0.01 to 12.0 parts by mass, more preferably 0.05 to 10.0 parts by mass, and even more preferably 0.1 to 8.0 parts by mass, relative to 100 parts by mass of the photocurable resin component. The component (D) may be used alone or in combination of two or more types.

[0033] Other Additives The photocurable maleimide resin composition of the present invention may further contain various additives as required, provided that the effects of the present invention are not impaired. Examples of other additives are given below.

[0034] [Photocurable resin having a reactive group capable of reacting with a maleimide group] In the present invention, a photocurable resin (A') having a reactive group capable of reacting with a maleimide group other than the component (A) may also be added. The photocurable resin is not limited to a specific type, and examples thereof include various resins other than component (A), such as epoxy resins, phenolic resins, melamine resins, silicone resins, cyclic imide resins including maleimide compounds other than component (A), urea resins, thermosetting polyimide resins, modified polyphenylene ether resins, thermosetting acrylic resins, and epoxy-silicone hybrid resins. Examples of reactive groups that can react with maleimide groups include epoxy groups, maleimide groups, hydroxyl groups, acid anhydride groups, alkenyl groups such as allyl groups and vinyl groups, (meth)acrylic groups, and thiol groups.

[0035] From the viewpoint of reactivity, the reactive group of the photocurable resin is preferably a maleimide group or a (meth)acrylic group, provided that the amount of the photocurable resin having a reactive group capable of reacting with a maleimide group is 0 to 50 mass % of the total amount of the photocurable resin.

[0036] [Inorganic filler] In the present invention, an inorganic filler may be further added. It may be blended for the purpose of increasing the strength or rigidity of the cured product of the photocurable maleimide resin composition of the present invention, or adjusting the thermal expansion coefficient or dimensional stability of the cured product. As the inorganic filler, those usually blended in epoxy resin compositions or silicone resin compositions can be used. For example, silicas such as spherical silica, fused silica, and crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, barium sulfate, talc, clay, aluminum hydroxide, magnesium hydroxide, calcium carbonate, glass fiber, and glass particles may be mentioned. Furthermore, fluorine-containing resins, coating fillers, and / or hollow particles may be added to improve the dielectric properties. The inorganic filler may be used alone or in combination of two or more types.

[0037] The average particle size and shape of the inorganic filler are not particularly limited, but spherical silica having an average particle size of 0.5 to 5 μm is preferably used. The average particle size is the mass average particle size D 50 (or median diameter).

[0038] Furthermore, in order to improve the properties of the inorganic filler, it is preferable that the inorganic filler is surface-treated with a silane coupling agent having an organic group capable of reacting with a maleimide group, such as an epoxy group-containing alkoxysilane, an amino group-containing alkoxysilane, a (meth)acrylic group-containing alkoxysilane, and an alkenyl group-containing alkoxysilane. As the silane coupling agent, an alkoxysilane containing a (meth)acrylic group and / or an amino group is preferably used, and specific examples thereof include 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, and 3-aminopropyltrimethoxysilane.

[0039] The blending amount of the inorganic filler is 0 to 70 mass % in the total amount of the photocurable resin from the viewpoint of light transmittance.

[0040] [others] In addition to the above, photosensitizers, non-functional silicone oils, thermoplastic resins, thermoplastic elastomers, organic synthetic rubbers, light stabilizers, flame retardants, pigments, dyes, etc. may be blended.

[0041] [Manufacturing method] The photocurable maleimide resin composition of the present invention can be produced by mixing the above-mentioned components. The photocurable maleimide resin composition of the present invention can be dissolved in an organic solvent and treated as a varnish, and the photocurable maleimide resin composition can be produced as a varnish by mixing each of the above-mentioned components with an organic solvent. Any organic solvent can be used without limitation as long as it dissolves the photocurable resin having a reactive group capable of reacting with the maleimide group as the component (A) and other additives, and examples of the organic solvent include anisole, xylene, toluene, tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and acetonitrile. These may be used alone or in combination of two or more.

[0042] Alternatively, if component (A) is liquid at room temperature, the individual components can be blended and mixed using a planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.) or a mixer such as a THINKY CONDITIONING MIXER (manufactured by Thinky Corporation). Alternatively, the components may be premixed and extruded into a sheet or film using a melt kneader, and then used as is. Furthermore, the sheet or film may be processed into granules or tablets.

[0043] [Application] The photocurable maleimide resin composition of the present invention can be used for applications requiring an insulating resin composition, and is not particularly limited, but as long as it is a resin composition that can be formed into a film at room temperature, it can be used for applications such as photosensitive films, photosensitive films with supports, insulating resin sheets such as prepregs, circuit boards (for laminates, multilayer printed wiring boards, etc.), solder resists, underfill materials, die bonding materials, semiconductor encapsulants, hole filling resins, component embedding resins, adhesives for bonding metal to metal, etc. In particular, it can be suitably used as a resin composition for insulating layers of multilayer printed wiring boards, solder resists, and adhesives used in areas that cannot be exposed to much heat.

[0044] The photocurable maleimide resin composition of the present invention is cured by irradiation with light under the usual conditions of wavelength, illuminance, time, etc., as the curing conditions for a photocurable resin, and is cured, for example, by irradiation with UV light of 365 nm, etc. Depending on the application, photocuring under the above-mentioned conditions may be combined with thermal curing under conditions such as 180°C for 1 hour. EXAMPLES

[0045] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0046] [(A) Maleimide compound] (A-1): A linear alkylene group-containing bismaleimide compound represented by the following formula (product name: BMI-3000J, manufactured by Designer Molecules Inc.) [ka] -C 36 H 72 - indicates a structure derived from a dimer acid skeleton. n≒5 (average value) (A-2): 1,6-bismaleimide-(2,2,4-trimethyl)hexane (product name: BMI-TMH, manufactured by Daiwa Chemical Industry Co., Ltd.)

[0047] [(A') Photocurable resin having a reactive group capable of reacting with a maleimide group (maleimide compound other than component (A)] (A-3): 4,4'-diphenylmethane bismaleimide (product name: BMI-1000, manufactured by Daiwa Chemical Industry Co., Ltd.) (A-4): Bisphenol A-diphenyl ether bismaleimide (product name: BMI-4000, manufactured by Daiwa Chemical Industry Co., Ltd.)

[0048] [(B) Polymerization inhibitor] (B-1) 4,4'-butylidene-bis(6-tert-butyl-m-cresol) (trade name: ANTAGE W-300, manufactured by Kawaguchi Chemical Industry Co., Ltd.)

[0049] [(C) Photocuring initiator] (C-1): Bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide (product name: Ominirad819, manufactured by iGM Resins)

[0050] [(D) Adhesive assistant] (D-1): 3-methacryloxypropyltrimethoxysilane (product name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0051] [Examples 1 to 3, Comparative Examples 1 to 10] <Preparation of varnish> The components shown in Tables 1 and 2 were added to a 500 mL four-neck flask equipped with a Dimroth condenser and a stirrer, and the mixture was stirred at 50°C for 2 hours to obtain a varnish-like resin composition.

[0052] <Varnish stability> The varnish prepared by the above method was transferred to a colorless, transparent glass bottle, which was then stoppered. The state of the varnish after production was checked and the stability of the varnish was evaluated as follows: those that had fluidity were rated as ○, those that had fluidity but had fine insoluble matter present were rated as △, and those that had completely gelled and lost fluidity were rated as ×. Next, the glass bottle containing the varnish was left in a stoppered state for two months in an incubator at 40° C. The state of the varnish after two months was checked, and the storage stability of the varnish was evaluated based on the following criteria: ◯: those that maintained their fluidity, △: those that had fluidity but had fine insoluble matter generated within, and ×: those that had completely gelled and lost fluidity.

[0053] <Dielectric constant, dielectric tangent, hardening> The varnish-like photocurable cyclic imide resin composition prepared by the above method was applied to a PET film having a thickness of 38 μm using a roller coater, and the film was dried at 100° C. for 10 minutes in the examples and comparative examples 1 to 3, 5, and 6, and at 180° C. for 10 minutes in the comparative examples 4 and 7 to 10, to obtain an uncured resin film having a thickness of 50 μm. Next, the uncured resin film thus obtained was dried at 2000 mJ / cm 2 The resin was irradiated with UV light and photocured to obtain a cured resin film. Using this cured resin film, a network analyzer (manufactured by Keysight, product name: E5063-2D5) and a strip line (manufactured by Keycom Corporation) were connected to measure the relative dielectric constant and dielectric loss tangent of the cured resin film at a frequency of 10 GHz. In addition, the cured resin film was immersed in anisole for 6 hours, and the curability was evaluated by assigning a weight change of 0.1% or less to the initial weight as "good" and a weight change of more than 0.1% as "bad."

[0054] <Adhesion to copper foil and glass> The varnish-like photocurable cyclic imide resin composition prepared by the above method was applied to a copper foil (trade name: TQ-M4-VLP, manufactured by Mitsui Metals) with Rz=0.6 μm and a thickness of 18 μm with a roller coater, and dried at 100 ° C for 10 minutes to prepare an uncured resin film with a thickness of 50 μm on the copper foil. A slide glass (trade name: S1111, manufactured by Matsunami Glass Industry Co., Ltd.) was laminated on the surface on which the uncured resin film was formed on the copper foil using a vacuum press (manufactured by Nikko Materials Co., Ltd., product name: V-130) under conditions of 100 ° C, 0.3 MPa pressure, and 60 seconds. It was applied from the slide glass side at 2000 mJ / cm 2The resin was then irradiated with UV light, photocured, and then thermally cured at 180°C for an additional hour. To evaluate adhesion, the 90° peel adhesion strength (kN / m) was measured when the copper foil of the adhesive test piece was peeled from the slide glass initially and after 168 hours at 85°C and 85% RH under conditions of 23°C and a tensile speed of 50 mm / min in accordance with JIS-C-6481 "Test methods for copper-clad laminates for printed wiring boards."

[0055] [Table 1]

[0056] [Table 2] *The copper foil was peeled off from the glass surface before the peel test was conducted, and the peel strength with the copper foil could not be measured due to insufficient adhesion to the glass. **After curing, peeling from the copper foil was observed due to insufficient adhesive strength, so measurement was not possible.

[0057] From the above, it has been confirmed that the photocurable maleimide resin composition of the present invention has excellent dielectric properties (low relative dielectric constant and low dielectric tangent), excellent storage stability and adhesive strength, and is useful as an adhesive for protective films such as wiring interlayer insulating layers and solder resists, and for glass substrates, etc.

Claims

1. (A) a maleimide compound having one or more saturated or unsaturated divalent aliphatic hydrocarbon groups having 6 to 200 carbon atoms per molecule; (B) a polymerization inhibitor, in an amount of 0.01 to 0.50 parts by mass per 100 parts by mass of the component (A), (C) 0.1 to 5.0 parts by mass of a photocuring initiator based on 100 parts by mass of the (A) component and (D) 0.1 to 5.0 parts by mass of an adhesive aid having a functional group capable of reacting with the maleimide group in component (A), selected from a maleimide group, an epoxy group, a (meth)acrylic group, a vinyl group, an allyl group, a phenolic hydroxyl group, and an amino group, per 100 parts by mass of component (A). A photocurable maleimide resin composition comprising The photocurable maleimide resin composition comprises a maleimide compound as component (A) in an amount of 80 to 100 mass % and a photocurable resin other than component (A) having a reactive group capable of reacting with a maleimide group in an amount of 0 to 20 mass %.

2. 2. The photocurable maleimide resin composition according to claim 1, wherein the maleimide compound of component (A) is a bismaleimide compound having two maleimide groups in one molecule.

3. 3. The photocurable maleimide resin composition according to claim 1, wherein the maleimide compound of component (A) has one or more hydrocarbon groups derived from a dimer acid skeleton in one molecule.

4. 4. The photocurable maleimide resin composition according to claim 1, wherein the maleimide compound of component (A) is a maleimide compound represented by the following formula (1) and has at least one dimer acid skeleton in one molecule: 【Chemistry 1】 (In formula (1), A's are independently tetravalent organic groups having a cyclic structure, B's are independently divalent hydrocarbon groups having 6 to 200 carbon atoms, and at least one of them is a dimer acid skeleton. n is 0 to 100.)

5. 5. The photocurable maleimide resin composition according to claim 4, wherein A in formula (1) is any one of tetravalent organic groups represented by the following structural formulas: 【Chemistry 2】 (The bond not bonded to a substituent in the above structural formula is bonded to the carbonyl carbon that forms a cyclic imide structure in formula (1).)

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