Photocurable polymer resin composition

Abstract

To provide a photocurable maleimide resin composition which is formed in a cured product that has excellent dielectric characteristics, has a high glass transition temperature and has a small coefficient of thermal expansion, and is excellent in curability.SOLUTION: A photocurable maleimide resin composition contains (A) a maleimide compound represented by a general formula (1), and (B) a photocuring initiator. In the 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, Q is independently a divalent alicyclic hydrocarbon group having a cyclohexane skeleton and 6 to 60 carbon atoms, W is B or Q, at least one of B and W is a dimer acid skeleton-derived hydrocarbon group, n is 1 to 100, and m is 1 to 200. The order of each of the repeating units sandwiched by n and m is not restricted, and a coupling scheme may be alternate, block or random.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Light-curing resins (photosensitive resins), such as UV-curing resins, are already being used in many places. UV-curing resins can be broadly divided into types that cure through radical polymerization of unsaturated double bonds such as acrylic groups, and types that cure through cationic polymerization such as epoxy groups, but generally 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), but there have been reports of attempts to solve these problems by using special colored but transparent maleimide resins (Patent Documents 1 to 5).

[0005] However, the special maleimide compounds used in the aforementioned report have many linear or branched alkyl groups, and tend to have excellent dielectric properties due to their low crosslink density. On the other hand, it is known that the drawbacks of low crosslink density include a large coefficient of thermal expansion (CTE) and a low glass transition temperature (Tg).

[0006] As a method for solving this problem, the use of a polymeric aromatic maleimide compound has been reported (Patent Document 6). It was found that the dielectric properties of the cured product of a composition containing the polymeric aromatic maleimide compound are poorer than other resins (high relative dielectric constant and high dielectric loss tangent), the composition has poor photocurability to begin with, and is easily dissolved when exposed to a solvent after being irradiated with light. [Prior art documents] [Patent documents]

[0007] [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 [Patent Document 6] JP 2020-33471 A Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, an object of the present invention is to provide a photocurable maleimide resin composition having excellent curability, which gives a cured product having excellent dielectric properties, a high glass transition temperature, and a small thermal expansion coefficient. [Means for solving the problem]

[0009] 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.

[0010] <1> (A) A maleimide compound represented by the general formula (1) and (B) Photocuring initiator A photocurable maleimide resin composition comprising: [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, Q is independently represented by the following formula (2): [ka] (In formula (2), R 1 are independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x1 and x2 are each independently a number from 0 to 4. is a divalent alicyclic hydrocarbon group having 6 to 60 carbon atoms and a cyclohexane skeleton represented by W is B or Q; At least one of B and W is a hydrocarbon group derived from a dimer acid skeleton, n is 1 to 100, and m is 1 to 200. The order of the repeating units bracketed by n and m is not limited, and the bonding pattern may be alternating, block, or random. <2> In formula (1), A is any of the tetravalent organic groups represented by the following structural formulas: <1> 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).) <3> Furthermore, the component (C) contains a polymerization inhibitor. <1> or <2> 2. The photocurable maleimide resin composition according to claim 1 . <4> The content of the photocuring initiator of the component (B) is 0.1 to 5.0 parts by mass per 100 parts by mass of the component (A). <1> ~ <3> 13. The photocurable maleimide resin composition according to claim 12. <5> The content of the polymerization inhibitor in the component (C) is 0.01 to 0.50 parts by mass per 100 parts by mass of the component (A). <3> or <4> 2. The photocurable maleimide resin composition according to claim 1 . <6> Further, the adhesive agent (D) is contained. <1> ~ <5> 13. The photocurable maleimide resin composition according to claim 12. <7> The adhesive aid of component (D) has a functional group capable of reacting with the maleimide group in component (A). <6> 2. The photocurable maleimide resin composition according to claim 1 . Effect of the Invention

[0011] The photocurable maleimide resin composition of the present invention is a photocurable resin composition that gives a cured product having excellent dielectric properties (low relative dielectric constant and low dielectric tangent), a high glass transition temperature, and a small thermal expansion coefficient. Furthermore, the photocurable maleimide resin composition of the present invention has excellent curability without dissolving into a solvent after irradiation with light. Therefore, the photocurable maleimide resin composition of the present invention is useful, for example, as a protective film for wiring interlayer insulating layers and solder resists. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0013] [(A) Maleimide compound having one or more saturated or unsaturated divalent hydrocarbon groups having 6 to 200 carbon atoms per molecule] The component (A) used in the present invention is a specific maleimide compound represented by the following formula (1), which is a maleimide compound having one or more saturated or unsaturated divalent hydrocarbon groups having 6 to 200 carbon atoms per molecule and at least one dimer acid skeleton per molecule. [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, Q is independently represented by the following formula (2): [ka] (In formula (2), R 1 are independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x1 and x2 are each independently a number from 0 to 4. is a divalent alicyclic hydrocarbon group having 6 to 60 carbon atoms and a cyclohexane skeleton represented by W is B or Q; At least one of B and W is a hydrocarbon group derived from a dimer acid skeleton, n is 1 to 100, m is 1 to 200, the order of the repeating units bracketed by n and m is not limited, and the bonding pattern may be alternating, block, or random.

[0014] Use of the maleimide compound represented by formula (1) results in a highly reliable composition that has excellent dielectric properties both before and after curing, strong adhesion to copper foil, and a high Tg.

[0015] The maleimide compound of the component (A) has a divalent aliphatic hydrocarbon group, and one hydrocarbon group in each molecule is derived from a dimer acid skeleton.

[0016] 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]

[0017] In addition, in the formula (1), Q independently represents the following formula (2): [ka] (In formula (2), R 1 are independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x1 and x2 are each independently a number from 0 to 4. It is a divalent alicyclic hydrocarbon group having a cyclohexane skeleton and having 6 to 60, preferably 7 to 30, and more preferably 8 to 20 carbon atoms, represented by the following formula:

[0018] Here, R 1 Specific examples of R include a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. Among these, a hydrogen atom and a methyl group are preferable. 1may be the same or different. Moreover, the above x1 and x2 each independently represent a number from 0 to 4, and preferably a number from 0 to 2. Note that x1 and x2 may be the same or different.

[0019] Specific examples of Q include divalent alicyclic hydrocarbon groups represented by the following structural formulas. [ka] (The bond not bonded to a substituent in the above structural formula is bonded to the nitrogen atom forming a cyclic imide structure in formula (1).)

[0020] In the formula (1), W is B or Q. Regarding W, the structural unit having B or Q is determined depending on the production method.

[0021] In the formula (1), n ​​is 1 to 100, preferably 1 to 60, and more preferably 2 to 50, and m is 1 to 200, preferably 1 to 50, and more preferably 3 to 40. If n or m is too large, the fluidity may decrease, and moldability may be poor. The order of the repeating units bracketed by n and m is not limited, and the bonding pattern may be alternating, block, or random.

[0022] In addition, in the formula (1), A independently represents a tetravalent organic group having a cyclic structure, and among these, it is preferable that A is any of the tetravalent organic groups represented by the following structural formulas. [ka]

[0023] 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 6 to 200 carbon atoms, preferably 8 to 100, and more preferably 10 to 50 carbon atoms. The branched divalent hydrocarbon group may be either a saturated aliphatic hydrocarbon group or an unsaturated hydrocarbon group, and may have an alicyclic structure or an aromatic ring structure in the middle of the molecular chain. 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.

[0024] 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.

[0025] [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)

[0026] [(B) Photocuring initiator] The photocuring initiator (B) 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.

[0027] 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, and acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and benzophenone compounds.

[0028] The content of the photocuring initiator of the component (B) is preferably 0.1 to 5.0 parts by mass, more preferably 0.2 to 4.5 parts by mass, and even more preferably 0.5 to 4.0 parts by mass, relative to 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 0.1 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 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 component (B) 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 composition may lack storage stability even if a polymerization inhibitor described below is added. The component (B) may be used alone or in combination of two or more.

[0029] 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.

[0030] [(C) Polymerization inhibitor] The photocurable maleimide resin composition of the present invention may contain a polymerization inhibitor as component (C). The polymerization inhibitor is added to enhance the storage stability of the photocurable resin composition of the present invention, and is not particularly limited as long as it can enhance the storage stability.

[0031] 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, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, etc.; naphthalene compounds such as 1,4-dihydroxy-2-naphthalenesulfonate, 4-methoxy-1-naphthol, etc.; naphthoquinone compounds such as 1,4-naphthoquinone, 2-hydroxy-1,4-naphthoquinone, anthrone, etc.; and phenolic antioxidants such as pyrogallol, phloroglucin, 4,4'-butylidene-bis(6-tert-butyl-m-cresol), etc.

[0032] The content of the polymerization inhibitor of the component (C) 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 amount 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 photocurable resin component. When the amount of the (C) component is less than 0.01 part by mass per 100 parts by mass of the (A) component, the polymerization inhibitory effect may be weakened. When the amount is more than 0.50 parts by mass, the effect reaches a plateau, and not only is it difficult to expect significant improvement in storage stability, but curability may also be affected. The component (C) may be used alone or in combination of two or more types.

[0033] [(D) Adhesive assistant] The photocurable maleimide resin composition of the present invention may contain an adhesive aid as component (D). The adhesive aid is added to improve the adhesive strength of the photocurable resin composition of the present invention. The maleimide compound of component (A) has strong adhesive strength to metals, and by adding component (D), the adhesive strength of the composition to some substances such as glass can be further improved.

[0034] Examples of the adhesion promoter include a silane coupling agent, a triazole-based compound, and a tetrazole-based compound.

[0035] The adhesive aid may be of any type, but preferably has a functional group capable of reacting with the maleimide group in component (A). Examples of functional groups 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 at least one of maleimide groups and (meth)acrylic groups, which have excellent photocuring properties, are preferred.

[0036] 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.

[0037] 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.

[0038] [Photocurable resin having reactive groups capable of reacting with maleimide groups] 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.

[0039] 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.

[0040] [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.

[0041] 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).

[0042] 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.

[0043] 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.

[0044] [others] In addition to the above, non-functional silicone oil, thermoplastic resin, thermoplastic elastomer, organic synthetic rubber, light stabilizer, flame retardant, pigment, dye, etc. may be blended.

[0045] [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.

[0046] 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.

[0047] [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, and adhesives for bonding metals to metals. Among these, it can be suitably used as a resin composition for insulating layers of multilayer printed wiring boards or as a solder resist. On the other hand, when it is liquid at room temperature, it is suitably used as an adhesive, particularly an adhesive for use in areas where little heat can be applied.

[0048] 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

[0049] 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.

[0050] [(A) Maleimide compound] (A-1): A linear alkylene group-containing bismaleimide compound represented by the following formula (product name: X-45-2600, manufactured by Shin-Etsu Chemical Co., Ltd.) [ka] -C 36 H 72 - indicates a structure derived from a dimer acid skeleton. n≒5 (average value), m≒1 (average value) (A-2): A linear alkylene group-containing bismaleimide compound represented by the following formula (product name: BMI-2500, manufactured by Designer Molecule Inc.) [ka] -C 36 H 72 - indicates a structure derived from a dimer acid skeleton. n≒5 (average value), m≒1 (average value)

[0051] [(A') Photocurable resin having a reactive group capable of reacting with a maleimide group (maleimide compound other than component (A)] (A-3): A linear alkylene group-containing bismaleimide compound represented by the following formula (product name: BMI-3000, manufactured by Designer Molecules Inc.) [ka] -C 36 H 72 - indicates a structure derived from a dimer acid skeleton. n≒5 (average value) (A-4): Aromatic maleimide having the following structure (product name: BMI-6100, manufactured by Designer Molecules Inc.) [ka] n≒8 (average value), m≒1 (average value) (A-5): 4,4'-diphenylmethane bismaleimide (product name: BMI-1000, manufactured by Daiwa Chemical Industry Co., Ltd.) (A-6): Bisphenol A-diphenyl ether bismaleimide (product name: BMI-4000, Daiwa Chemical Industry Co., Ltd.)

[0052] [(B) Photocuring initiator] (B-1): Bis(2,4,6-trimethylbenzoyl)-phenyl-phosphine oxide (product name: Ominirad819, manufactured by iGM Resins)

[0053] [(C) Polymerization inhibitor] (C-1) 4,4'-butylidene-bis(6-tert-butyl-m-cresol) (trade name: ANTAGE W-300, manufactured by Kawaguchi Chemical Industry Co., Ltd.)

[0054] [(D) Adhesive assistant] (D-1): 3-methacryloxypropyltrimethoxysilane (product name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0055] [Examples 1 to 3, Comparative Examples 1 to 7] <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.

[0056] <Dielectric constant, dielectric tangent, glass transition temperature, thermal expansion coefficient, 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, and at 180° C. for 10 minutes in the comparative examples 4 to 7, to obtain an uncured resin film having a thickness of 50 μm. Next, the uncured resin film obtained was subjected to a drying treatment of 2000 mJ / cm 2 The resin was then exposed to UV light for 3 seconds for photocuring 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 glass transition temperature (Tg) and the coefficient of thermal expansion (CTE, 0 to 40° C.) of the cured resin film were measured using a DMA-800 manufactured by TA Instruments. Furthermore, the photocured resin film was immersed in anisole for 6 hours, and the curability was evaluated by assigning a weight change of 0.3% or less to the initial weight as "good" and a weight change of more than 0.3% as "bad."

[0057] <Adhesion to copper foil> 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 2 The resin was then exposed to UV light for 3 seconds, photocured, and then thermally cured at 180°C for an additional hour. To evaluate the adhesion, the 90° peel adhesion strength (kN / m) was measured when peeling the copper foil of the adhesive test piece from the slide glass at a temperature 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."

[0058] [Table 1]

[0059] [Table 2] *1: Poor appearance and tendency to separate. *2: Two inflection points were observed in the TMA curve.

[0060] 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), a high glass transition temperature, and a small thermal expansion coefficient when cured, and is therefore useful as a protective film for wiring interlayer insulating layers and solder resists, etc.

Claims

1. (A) a maleimide compound represented by general formula (1), (B) 0.1 to 5.0 parts by mass of a photocuring initiator relative to 100 parts by mass of the (A) component; (C) A polymerization inhibitor is used in an amount of 0.01 to 0.50 parts by mass per 100 parts by mass of the component (A). 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: 【Chemistry 1】 (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; Q is independently represented by the following formula (2): 【Chemistry 2】 (In formula (2), R 1 are independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x1 and x2 are each independently a number from 0 to 4. is a divalent alicyclic hydrocarbon group having 6 to 60 carbon atoms and a cyclohexane skeleton represented by W is B or Q; At least one of B and W is a hydrocarbon group derived from a dimer acid skeleton, n is 1 to 100, and m is 1 to 200. The order of the repeating units bracketed by n and m is not limited, and the bonding pattern may be alternating, block, or random.

2. 2. The photocurable maleimide resin composition according to claim 1, wherein A in formula (1) is any one of tetravalent organic groups represented by the following structural formulas: 【Chemistry 3】 (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).)

Images