WO2019078300A1 - Curable resin composition, varnish, prepreg, cured product, laminate and copper-clad laminate - Google Patents

Abstract

Provided is a curable resin composition that exhibits excellent solubility in solvents and enables the achievement of a cured product which has excellent heat resistance, thermal decomposition characteristics, dielectric characteristics, water absorption characteristics and chemical resistance, and which is suitable for a fiber-reinforced composite material that is used in printed wiring boards for electronic devices or in the field of aerospace. A curable resin composition which contains (A) a maleimide resin and (B) a benzoxazine resin that is represented by formula (1). (In formula (1), n represents the average of the numbers of repetitions, which is a real number of 1-10; each of R1-R8 independently represents a hydrogen atom, a halogen atom, an alkyl group having 1-8 carbon atoms or an aryl group; in cases where there are a plurality of each of the R3-R7 moieties, the R3-R7 moieties may be the same as or different from each other, respectively; each of R9 and R10 independently represents a hydrogen atom, an alkyl group having 1-8 carbon atoms, an aryl group, an allyl group or an alkoxy group; in cases where there are a plurality of each of the R9 and R10 moieties, the R9 and R10 moieties may be the same as or different from each other, respectively; and the dotted lines indicate that a benzene ring may be formed.)

Description

Curable resin composition, varnish, prepreg, cured product, and laminate or copper-clad laminate

The present invention relates to a curable resin composition containing a maleimide resin and a benzoxazine resin, a varnish, a prepreg, a cured product, and a laminate or a copper-clad laminate. Specifically, maleimide resin and benzo useful in insulating materials for electric and electronic parts, semiconductor sealing material applications, laminates (printed wiring boards, build-up substrates, etc.), various composite materials including CFRP, adhesives, paints, etc. The present invention relates to a curable resin composition containing an oxazine resin and a cured product thereof.

By curing with a variety of curing agents, epoxy resins, which are thermosetting resins, generally become cured products excellent in mechanical properties, water resistance, chemical resistance, heat resistance, electrical properties, etc. It is used in a wide range of fields such as paints, laminates, molding materials, casting materials, and sealing materials. In recent years, with the expansion of the field of use of laminates on which electrical and electronic components are mounted, the required characteristics have been broadened and advanced.

In recent years, with the advancement of power semiconductors in particular, wide band gap devices such as SiC (silicon carbide) and GaN (gallium nitride) have attracted attention as next-generation devices. The use of SiC and GaN power semiconductor devices enables space saving due to miniaturization and a significant loss reduction, and therefore the early spread of SiC and GaN devices is desired. However, since the driving temperature for extracting the characteristics is as high as 200 ° C. or higher (around 250 ° C.), the durability of the peripheral materials is not sufficient, and development of a resin material that can withstand this driving condition is required (Patent Literature 1). Therefore, not only the heat resistance (glass transition temperature) of 200 ° C. or more but also the thermal stability are regarded as important in such applications, and it is considered difficult to use an epoxy resin whose thermal decomposition starts from around 200 ° C.

Furthermore, in recent years, high-speed communication in these electronic devices has attracted particular attention. The amount of information communication of smartphones and tablets has become extremely large as well as high frequency substrates, and it has become important how quickly to transmit a lot of information. Since high speed communication is an important factor for the package substrate, dielectric characteristics, in particular, dielectric loss tangent is regarded as important. While the dielectric loss tangent of a common epoxy resin cured product (resin only) is 0.02 to 0.04 (measured at 1 GHz), the required dielectric loss tangent is 0.009 or less, and the dielectric loss tangent is There is an urgent need to develop materials that also meet the characteristics.

Therefore, studies are being made to blend a highly heat resistant maleimide resin and a highly tough benzoxazine resin. Patent Document 2 describes that a mixture of a benzoxazine resin having a bisphenol F skeleton and a maleimide resin is used to improve heat resistance.

Moreover, in the printed wiring board used for the manufacture of a package, in order to conduct between conductor patterns of different layers, drilling is performed by drilling or laser processing, but resin is formed inside the hole at the time of this drilling. Smear occurs. Therefore, desmear treatment for removing such resin smear is essential. Desmear treatment is performed, for example, using a permanganate such as potassium permanganate.

Japanese Unexamined Patent Publication No. 2017-128782 Japan JP 2012-97207

However, the technology described in Patent Document 2 is not sufficient to obtain the characteristics of the dielectric loss tangent.
In addition, when the amount of resin smear removed by desmear treatment (desmear etching amount) is large, deformation of a hole, peeling of copper foil and the like occur, which causes a decrease in conduction reliability, so to reduce the amount of desmear etching In addition, chemical resistance (acid resistance, alkali resistance and desmear liquid resistance) is required.
The present invention has been made in view of such a situation, and is excellent in solvent solubility, and a cured product thereof is a maleimide resin excellent in heat resistance, thermal decomposition characteristics, water absorption characteristics, dielectric characteristics, and chemical resistance. An object of the present invention is to provide a curable resin composition containing a benzoxazine resin, a varnish, a prepreg, a cured product, and a laminate or a copper-clad laminate.

As a result of intensive investigations, the present inventors found that a curable resin composition containing a maleimide resin and a benzoxazine resin of a specific structure is excellent in solvent solubility, and the cured product has heat resistance, thermal decomposition characteristics, water absorption characteristics, and dielectric properties. It has been found that the properties and chemical resistance are excellent, and the present invention has been completed.

That is, the present invention
[1] A curable resin composition containing a maleimide resin (A) and a benzoxazine resin (B) represented by the following formula (1),

(In formula (1), n is an average value of the number of repetitions and represents a real number of 1 to 10. R ₁ to R ₈ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group _{If .R} 3 ~ _{R 7} represent either a group is present in plural, each of _R 3 ~ _{R 7} is optionally being the same or different _{.R 9, R 10} each independently represent a hydrogen atom Or an alkyl group having 1 to 8 carbon atoms, an aryl group, an allyl group or an alkoxy group, and when a plurality of R _{9 s} and R _{10 s} are present, each R _{9 s} and R _{10 s} may be identical to each other The dotted line may indicate that a benzene ring may be formed.)

[2] The curable resin composition according to the preceding item [1], wherein R ₁ to R ₈ in the formula (1) are hydrogen atoms,
[3] The curable resin composition according to the above [1] or [2], which contains one or more resins selected from aromatic maleimide resin and aliphatic maleimide resin as the maleimide resin (A).
[4] The curable resin composition according to any one of [1] to [3], further containing a cyanate ester resin,
[5] A cured product obtained by curing the curable resin composition according to any one of the above items [1] to [4],
[6] A varnish obtained by dissolving the curable resin composition according to any one of the above items [1] to [4] in a solvent,
[7] A prepreg obtained by impregnating a base material with the varnish according to the preceding item [6],
[8] A cured product obtained by curing the prepreg according to the previous item [7],
[9] A laminate or a copper-clad laminate obtained by using the prepreg according to the preceding paragraph [7],
It is about

The curable resin composition of the present invention is excellent in solvent solubility, and the cured product is excellent in heat resistance, thermal decomposition characteristics, water absorption characteristics, dielectric characteristics, chemical resistance, and so on. It is useful for laminates (printed wiring boards, build-up substrates, etc.), various composite materials including CFRP, adhesives, paints, etc.

The results of ¹ H-NMR analysis of the benzoxazine resin obtained in Synthesis Example 2 are shown. The results of ¹ H-NMR analysis of the benzoxazine resin obtained in Synthesis Example 3 are shown. The MDSC measurement result of the resin composition of Example 10, Comparative Example 4 and 5 is shown.

The curable resin composition of the present invention contains a maleimide resin (A).
The maleimide resin (A) used in the present invention is a compound containing one or more maleimide groups in the molecule, and known compounds can be used. For example, aliphatic / alicyclic maleimide resin, aromatic maleimide resin and the like can be mentioned.
Specific examples of the maleimide resin (A) used in the present invention include N-methyl maleimide, N-ethyl maleimide, N-propyl maleimide, N-hexyl maleimide, N-cyclohexyl maleimide, maleimide carboxylic acid, N-phenyl maleimide, Polyfunctional maleimide compounds obtained by the reaction of N-methylphenyl maleimide, 3,4,4'-triaminodiphenylmethane, triaminophenol etc. with maleic anhydride, tris- (4-aminophenyl) -phosphate, tris (4) -Aminophenyl) -phosphate, a maleimide compound obtained by the reaction of tris (4-aminophenyl) -thiophosphate with maleic anhydride, a trismaleimide compound such as tris (4-maleimidophenyl) methane, bis (3,4-) Dimaleimidophenyl) Methane, tetramaleimide benzophenone, tetramaleimide naphthalene, tetramaleimide compounds such as maleimide obtained by reaction of triethylenetetramine and maleic anhydride, phenol novolac maleimide resin, isopropylidene bis (phenoxyphenyl maleimide) phenyl maleimide aralkyl resin, formula (2) Biphenylene type phenylmaleimide aralkyl resin represented by (2), polymaleimide represented by polymaleimide represented by formula (3) or formula (4), polyaniline of polyaniline obtained by condensation of benzenedialdehyde and aniline Maleimide and the like. Also, polyaminopolymaleimide resin obtained by adding aromatic diamine to these polymaleimides can be used. Further, since the novolac type maleimide resin has a molecular weight distribution, it has high varnish stability and is suitable for kneading with the benzoxazine resin. These may be commercially available ones and can also be produced using known methods.

(In the formula (2), a plurality of R _{21 s} independently exist and represent an alkyl group having 1 to 10 carbon atoms or an aromatic group, a represents 0 to 4 and b represents 0 to 3 N _a is the average value of the number of repetitions and represents a real number of 1 to 5.)

(In the formula (3), A is an alkylene group or alkylidene group having 1 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a ketone group, a single bond, R ₂₂ is present each independently represent a hydrogen atom , An aliphatic hydrocarbon group of 1 to 5 carbon atoms or a halogen atom.)

(In the formula (4), a plurality of R _{23 s} independently exist and represent an alkyl group having 1 to 10 carbon atoms or an aromatic group, a represents 0 to 4 and b represents 0 to 3 N _b is an average value of the number of repetitions and represents a real number of 0.01 to 8. Z represents an organic group having 1 to 8 carbon atoms.)

Note that equation (2) the value of n _a and n _b of formula (4) can be calculated from the value of the weight-average molecular weight determined by measurement of gel permeation chromatography (GPC). Specifically, it is calculated by the following formula.
n _a = [(weight average molecular weight) - (molecular weight of n _a = 1 body)] ÷ [(molecular weight of n _a = 2 body) - (molecular weight of n _a = 1 body)] + 1
n _b = [(weight average molecular weight)-(n _b = 0 molecular weight)] ÷ [(n _b = 1 molecular weight)-(n _b = 0 molecular weight)] + 1
The GPC measurement in the present invention was performed under the following conditions.
Column: Shodex KF-603, KF-602.5, KF-602, KF-601x2
Coupling eluent: tetrahydrofuran flow rate: 0.5 ml / min.
Column temperature: 40 ° C
Detection: RI (differential refraction detector)

The maleimide resin used in the present invention is preferably an aromatic maleimide compound, more preferably a polymaleimide represented by the above formulas (2) to (4), benzenedialdehyde and aniline from the viewpoint of heat resistance and thermal decomposition characteristics. Polymaleimide polymaleimide obtained by condensation with Moreover, polyamino polymaleimide resin which made aromatic diamine be added to these polymaleimide can also be used.

These maleimide resins may be used alone or in combination of two or more. An aromatic maleimide resin and an aliphatic maleimide resin may be used in combination.
In the present invention, an aromatic maleimide resin is particularly preferable in terms of heat resistance (glass transition point) and / or elastic modulus, and a combination with a maleimide resin having two or more functional groups in one molecule is preferable.

The maleimide resin used in the present invention can be one having a melting point or a softening point. When it has a melting point, 200 ° C. or less is preferable, and when it has a softening point, it is preferable that it is 150 ° C. or less. If the melting point or the softening point is too high, the possibility of gelation increases during mixing, which is not preferable.

The curable resin composition of the present invention contains a benzoxazine resin (B) represented by the following formula (1).

In the formula (1), n is an average value of the number of repetitions, and represents a real number of 1 to 10. Each of R ₁ to R ₈ independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group. When a plurality of R ₃ to R ₇ exist, each of R ₃ to R ₇ may be the same as or different from each other. R ₉ and R ₁₀ each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group, an allyl group or an alkoxy group. When a plurality of R _{9 s} and R _{10 s} are present, each R _{9 s} and R _{10 s} may be the same as or different from each other. The dotted line represents that a benzene ring may be formed.

The alkyl group having 1 to 8 carbon atoms represented by R ₁ to R ₈ and R ₉ and R _{10 in the} formula (1) is not limited to any of linear, branched or cyclic alkyl group, and specific examples thereof Examples include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, sec-butyl, n-pentyl, n-hexyl, n -Heptyl group, cyclopentyl group, cyclohexyl group etc. may be mentioned, and it is preferable that it is a linear or branched alkyl group having 1 to 8 carbon atoms, and is a linear or branched alkyl group having 1 to 4 carbon atoms It is more preferable that

The aryl group represented by R ₁ to R ₈ and R ₉ and R _{10 in the} formula (1) is a residue obtained by removing one hydrogen atom from an aromatic hydrocarbon, and specific examples thereof include a phenyl group and biphenyl. Groups, naphthyl groups, anthryl groups, phenanthryl groups, pyrenyl groups and benzopyrenyl groups.

The alkoxy group represented by R ₉ and R _{10 in} the formula (1) is a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, an iso-butoxy group, a tert-butoxy group, sec- Examples thereof include butoxy, n-pentoxy, n-hexyloxy, n-heptyloxy, cyclopentoxy and cyclohexyloxy groups, etc., and it is a linear or branched alkoxy group having 1 to 8 carbon atoms It is preferably, and more preferably a linear or branched alkoxy group having 1 to 4 carbon atoms.

R ₁ to R _{8 in} the formula (1) are preferably each independently a hydrogen atom, a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms, each independently having a hydrogen atom or a bromine atom. Or a linear alkyl group having 1 to 4 carbon atoms is more preferable, and a hydrogen atom is even more preferable.

R ₉ and R _{10 in} the formula (1) each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, a phenyl group, an allyl group, a linear or branched chain having 1 to 4 carbon atoms It is preferably a chain alkoxy group, more preferably a hydrogen atom, a methyl group, a phenyl group, an allyl group or a methoxy group, and still more preferably a hydrogen atom.

In the formula (1), n represents the average value of the number of repetitions, and is usually a real number of 1 to 10, preferably a real number of 1 to 5. The value of n can be calculated from the value of weight average molecular weight obtained by measurement of gel permeation chromatography (GPC). Specifically, it is calculated by the following formula.
n = [(weight average molecular weight)-(n = 1 molecular weight of one body)] ÷ [(n = 2 molecular weight of two body)-(n = 1 molecular weight of one body) +1
The GPC measurement in the present invention was performed under the following conditions.
Column: Shodex KF-603, KF-602.5, KF-602, KF-601x2
Coupling eluent: tetrahydrofuran flow rate: 0.5 ml / min.
Column temperature: 40 ° C
Detection: RI (differential refraction detector)

Further, as the benzoxazine resin represented by the formula (1), one having a bonding position of two methylene groups bonded to the biphenyl structure in the formula (1) is 4,4 ′, that is, in the following formula (5) More preferred are the benzoxazine resins represented.

N and R ₁ to R ₁₀ in the formula (5) have the same meanings as n and R ₁ to R ₁₀ in the formula (1). The dotted line represents that a benzene ring may be formed.

The benzoxazine resin represented by the formula (1) of the present invention can be prepared, for example, by using an aniline compound represented by the formula (6), a phenol compound represented by the formula (7) and an aldehyde compound as raw materials. It can be synthesized by a known method represented by the following reaction formula. Although formaldehyde is described as an example of the aldehyde compound in the reaction formula, paraformaldehyde or benzaldehyde may be used.

N and R ₁ to R ₈ in the formula (6) have the same meanings as n and R ₁ to R ₈ in the formula (1), and the preferred range is also the same.

R ₉ and R ₁₀ in the formula (7) have the same meanings as R ₉ and R ₁₀ in the formula (1), and the preferred range is also the same. The dotted line represents that a benzene ring may be formed.

The feed ratio of the phenol compound is preferably 0.5 to 1.2 moles, and more preferably 0.75 to 1.1 moles with respect to 1 mole of the amino group of the aniline compound. Further, the preparation ratio of the aldehyde compound is preferably 1.7 to 4.3 moles, and more preferably 1.8 to 4.2 moles relative to 1 mole of the phenol compound.
The reaction may be carried out in a solvent or without solvent. The solvent that can be used for the reaction is not particularly limited as long as it can dissolve the starting compound, and for example, methyl ethyl ketone, toluene, 1-propanol, 2-propanol, 1-butanol, 1,4-dioxane, ethylene glycol monomethyl ether, ethylene Examples thereof include glycol monoethyl ether and ethylene glycol monobutyl ether. These solvents may be used alone or in combination.
The reaction temperature is preferably 60 ° C. or higher. The reaction time is not particularly limited, and may be selected while confirming the progress of the reaction by confirming the residual amount of the raw material used for the reaction.
When a solvent is used, the benzoxazine resin can be obtained by removing the condensed water generated during the synthesis, the remaining raw materials, the solvent, etc. under reduced pressure after completion of the synthesis, but since it has self-polymerizability, it is at 160 ° C. or less Vacuum distillation is preferred.

The benzoxazine resin (B) used in the present invention can be one having a melting point or a softening point. When it has a melting point, 200 ° C. or less is preferable, and when it has a softening point, it is preferable that it is 150 ° C. or less. If the melting point or the softening point is too high, the possibility of gelation increases during mixing, which is not preferable.

Specific examples of the benzoxazine resin represented by the formula (1) of the present invention will be described below, but the present invention is not limited to these specific examples. Incidentally, n in the structural formula of the specific example has the same meaning as n in formula (1).

The benzoxazine resin contained in the curable resin composition of the present invention has self-curing (meaning that it can be ring-opening polymerized (cured) without other components such as a curing agent and a polymerization catalyst). That is, in addition to the fact that a curing catalyst and the like are not required at the time of curing, no by-products are generated in the polymerization process, and a polymer (cured product) with high dimensional stability without voids can be obtained. The conditions for the self-curing are preferably 200 ° C. or more and several tens minutes to several hours or so.

In general, it is known that a C—N bond is more likely to be thermally decomposed because a C—N bond has a smaller bonding energy than a C—O bond. Then, it is thought that liberation is prevented if the molecular skeleton adjacent to N is high molecular weight. Therefore, compared with a benzoxazine resin synthesized from a large molecular weight phenol compound and a small molecular weight aniline compound, the structure of the compound which prevents the release of aniline becomes the one synthesized from the large molecular weight aniline resin and the small molecular weight phenol compound. Therefore, the improvement of the thermal decomposition characteristics can be expected.

The compounding ratio of the benzoxazine resin to the maleimide resin in the curable resin composition of the present invention is not particularly limited, but 0.1 to 100 parts by mass of the maleimide resin with respect to 10 parts by mass of the benzoxazine resin Is more preferably 1 to 75 parts by mass, particularly preferably 5 to 50 parts by mass.

The curable resin composition of the present invention can be blended with a curing catalyst, a flame retardant, a filler, an additive and the like as required.
The curing catalyst is not particularly limited, and known catalysts can be used. Specific examples thereof include metal complex catalysts, phosphine compounds, compounds having phosphonium salts, aromatic amine compounds, inorganic acids, inorganic bases, organic acids and organic bases.
As the metal complex catalyst, generally known ones can be used. For example, metal naphthenic acid salts such as cobalt, zinc, chromium, copper, iron, manganese, nickel, titanium, acetylacetonate, salts of derivatives thereof, organic acid salts such as various carboxylate alkoxides, etc. You may mix and use. Organic acid salts, chlorides, phosphates, phosphites, hypophosphites, nitrates and the like alone or in mixtures thereof may also be mentioned as an example of the metal complex catalyst.
As phosphine compounds, alkyl phosphines such as ethyl phosphine and propyl phosphine, primary phosphines such as phenyl phosphine; dialkyl phosphines such as dimethyl phosphine and diethyl phosphine, secondary phosphines such as diphenyl phosphine, methyl phenyl phosphine and ethyl phenyl phosphine; trimethyl Trialkyl phosphines such as phosphine, triethyl phosphine, tributyl phosphine, trioctyl phosphine, tricyclohexyl phosphine, triphenyl phosphine, alkyl diphenyl phosphine, dialkyl phenyl phosphine, tribenzyl phosphine, tri tolyl phosphine, tri-p-styryl phosphine, tris ( 2,6-Dimethoxyphenyl) phosphine, tri-4-methylphenyl phosphi , Tri-4-methoxyphenyl phosphine, tertiary phosphines such as tri-2-cyanoethyl phosphine, and the like.
Examples of the compound having a phosphonium salt include compounds having a tetraphenyl phosphonium salt, an alkyltriphenyl phosphonium salt and the like, and specifically, tetraphenyl phosphonium thiocyanate, tetraphenyl phosphonium tetra-p-methylphenyl borate, butyl triphenyl And phosphonium thiocyanate.
Examples of the aromatic amine compound include tertiary amines and imidazoles. Specifically, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2,4-dimethylimidazole, 2- Undecylimidazole, 2-Heptadecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4 -Methyl-5-hydroxymethylimidazole, 1-vinyl-2-methylimidazole, 1-propyl-2-methylimidazole, 2-isopropylimidazole, 1-cyanomethyl-2-methyl-imidazole, 1-cyanoethyl-2-ethyl- 4-Methylimidazole 1-cyanoethyl-2-undecyl imidazole, 1-cyanoethyl-2-phenylimidazole, diazabicycloundecene, histidine and the like.
As inorganic acids, inorganic bases, organic acids and organic bases, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, sodium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, formic acid, acetic acid, citric acid, oxalic acid P-toluenesulfonic acid, benzoic acid, phenol, allylphenol, methallylphenol, thiophenol, pyridine, trialkylamine, diazabicycloundecene, histidine and imidazoles, etc., hydrochloric acid, p-toluenesulfonic acid Benzoic acid, phenol and thiophenol are preferred, and p-toluenesulfonic acid and 2-ethyl-4-methylimidazole are more preferred. These additives may be used alone or in combination of two or more.
The compounding amount of these curing catalysts may be appropriately selected depending on the type and effects thereof, but is preferably 0.001 parts by mass or more and 10 parts by mass or less, and more preferably 100 parts by mass of the curable resin composition. It is 0.01 parts by mass or more and 5 parts by mass or less, particularly preferably 0.05 parts by mass or more and 3 parts by mass or less.

Specific examples of the flame retardant include bromine compounds, phosphorus compounds, chlorine compounds, metal hydroxides and antimony compounds.

Specific examples of the filler include fumed silica, calcined silica, precipitated silica, crushed silica, fused silica, diatomaceous earth, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, Wax clay, kaolin clay, calcined clay, carbon black, polyamide resin, silicone resin, polytetrafluoroethylene, polybutadiene and its modified product, modified product of acrylonitrile copolymer, polyphenylene ether, polystyrene, polyethylene, polyimide, fluorocarbon resin, etc. And organic or inorganic fillers of various forms. These fillers may be used alone or in combination of two or more.

Specific examples of the additive include surface treatment agents, reaction retarders, coloring materials, antistatic agents, antiaging agents, antioxidants, and the like.
A silane coupling agent etc. are mentioned as a specific example of a surface treating agent.
Specific examples of the reaction retarder include compounds such as alcohols, and examples of anti-aging agents include compounds such as hindered phenols. Moreover, as an antioxidant, butyl hydroxytoluene (BHT), butyl hydroxy anisole (BHA) etc. are mentioned, for example.
Specific examples of coloring materials include titanium oxide, zinc oxide, ultramarine blue, bengala, lithopone, inorganic pigments such as lead, cadmium, iron, cobalt, aluminum, hydrochloride and sulfate; azo pigments, phthalocyanine pigments, quinacridone pigments, quinacridones Quinone pigment, dioxazine pigment, anthrapyrimidine pigment, anthanthrone pigment, indanthrone pigment, flavanthrone pigment, perylene pigment, perinone pigment, diketopyrrolopyrrole pigment, quinonaphthalone pigment, anthraquinone pigment, thioindigo pigment, benzimidazolone pigment, iso Examples thereof include indoline pigments, organic pigments such as carbon black, and the like.
Examples of the antistatic agent generally include quaternary ammonium salts; hydrophilic compounds such as polyglycols and ethylene oxide derivatives, and the like.

The curable resin composition of the present invention preferably further contains a cyanate ester resin. The curable resin composition of the present invention, by further containing a cyanate ester resin, enables curing at a lower temperature without using the above-mentioned curing catalyst.
In general, since the catalyst is expensive, it is preferable from the viewpoint of cost to cure the curable resin composition without adding the catalyst. In addition, if too much catalyst is added, the reliability of the resulting cured product such as heat resistance and mechanical strength is affected. In particular, metal complex catalysts often used for benzoxazine resins, cyanate ester resins, and maleimide resins, which incorporate metal ion components, may cause corrosion in electronic material applications.

The cyanate ester resin that can be used in the curable resin composition of the present invention is not particularly limited as long as it is a known cyanate ester resin, and for example, novolac type cyanate ester resin, bisphenol A type cyanate ester resin, bisphenol E type cyanate ester Resin, bisphenol type cyanate ester resin such as tetramethyl bisphenol F type cyanate ester resin; naphthol aralkyl type cyanate ester resin obtained by reaction of naphthol aralkyl type phenol resin with cyanogen halide; dicyclopentadiene type cyanate ester resin; biphenyl Alkyl-type cyanate ester resins, polycondensates of phenols with various aldehydes, polymers of phenols with various diene compounds, and phenols with ketones Cyanate ester resin obtained by reacting a condensate and polycondensates of bisphenols and various aldehydes such as cyanogen halide and the like.
Examples of the above-mentioned phenols include phenol, alkyl substituted phenol, aromatic substituted phenol, naphthol, alkyl substituted naphthol, dihydroxybenzene, alkyl substituted dihydroxybenzene and dihydroxynaphthalene.
Examples of the various aldehydes include formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde and cinnamaldehyde.
Examples of the various diene compounds include dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinyl norbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene, isoprene and the like.
Examples of the ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone and the like.
Among these, novolac type cyanate ester resins and naphthol aralkyl type cyanate ester resins are preferable, and novolac type cyanate ester resins are more preferable. By using the novolac type cyanate ester resin, the crosslink density of the obtained cured product is increased, and not only the heat resistance is improved, but also by the improvement of the benzene concentration, excellent thermal decomposition characteristics and flame retardancy can be expected. These may be used alone or in combination of two or more.
When a cyanate ester resin is used in the curable resin composition of the present invention, the lower limit value of the compounding amount is preferably 0.1 parts by mass, more preferably 1 with respect to 10 parts by mass of the benzoxazine resin from the viewpoint of heat resistance. It is part by weight, particularly preferably 3 parts by weight.
In addition, from the viewpoint of handling, the upper limit value of the compounding amount is preferably 100 parts by mass, more preferably 50 parts by mass, and particularly preferably 30 parts by mass with respect to 10 parts by mass of the benzoxazine resin. When the compounding amount of benzoxazine resin is too large, phase separation may occur with benzoxazine.

The curable resin composition of the present invention may contain copolymer components such as epoxy resin, phenol resin, melamine resin, unsaturated polyester resin, polyimide resin, polyamide resin, polyurethane resin and the like. These copolymerization components may be used alone or in combination of two or more.
Among these copolymerization components, it is preferable to blend an epoxy resin having reactivity with a phenolic hydroxyl group generated in the resin composition by heating, and a phenol resin, and it is particularly preferable to blend an epoxy resin.

The epoxy resin which can be blended is not particularly limited as long as it is a compound having at least one epoxy group, and examples thereof include bisphenol A, bisphenol F, bisphenol S, hexahydrobisphenol A, tetramethylbisphenol A, pyrocatechol, resorcinol, A glycidyl ether type obtained by the reaction of an epichlorohydrin with a polyphenol such as cresol novolak, phenol novolak, tetrabromobisphenol A, trihydroxybiphenyl, bisresorcinol, bisphenol hexafluoroacetone, tetramethyl bisphenol F, bixylenol, dihydroxynaphthalene, etc .; Glycerin, neopentyl glycol, ethylene glycol, propylene glycol, butylene glycol, hexi Polyglycidyl ether type obtained by the reaction of epichlorohydrin with aliphatic polyhydric alcohol such as glycol, polyethylene glycol and polypropylene glycol; by the reaction of epichlorohydrin with hydroxycarboxylic acid such as p-hydroxybenzoic acid and β-hydroxynaphthoic acid Obtained glycidyl ether ester type: phthalic acid, methyl phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid, endomethylene hexahydrophthalic acid, trimellitic acid, polymerized fatty acid, etc. Polyglycidyl ester type derived from polycarboxylic acid of glycidyl; glycidyl aminoglycidyl ether type derived from aminophenol, aminoalkylphenol etc .; aminobenzoic acid Glycidyl aminoglycidyl ester derived from aniline; derived from aniline, toluidine, tribromoaniline, xylylenediamine, diaminocyclohexane, bisaminomethylcyclohexane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone etc. Glycidyl amine type; and epoxidized polyolefin, glycidyl hydantoin, glycidyl alkyl hydantoin, triglycidyl cyanurate and the like. From the viewpoint of heat resistance improvement, novolac type epoxy and glycidyl amine type epoxy resins are preferable.

The curable resin composition of the present invention can also be used as a varnish dissolved in a solvent. The use of a varnish is a preferred embodiment in that handling of the curable resin composition is facilitated.

As a solvent which can be used for the varnish of the present invention, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dioxane, 1-propanol, 2-propanol, 1-butanol, 1, -butanol Although 4-dioxane, ethylene glycol ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, etc. may be mentioned, any solvent capable of dissolving the curable resin composition of the present invention may be used without particular limitation. Can.
The above-described additives and optional components may be blended into the varnish of the present invention as required.

The varnish containing the curable resin composition of the present invention is applied to various substrates, and the solvent is removed (dried) at a temperature of 150 ° C. or less, for example, and then treated at a high temperature of 200 ° C. or more Can be
Moreover, after impregnating the base materials, such as a glass nonwoven fabric, with the varnish of this invention and removing a solvent, it can also be set as fiber reinforced materials, such as a laminated board and a copper clad laminated board, using the prepreg obtained.

The present invention will now be described in more detail by way of examples. The present invention is not limited to these examples. The softening point and the melt viscosity in the synthesis examples were measured by the following methods.
Softening point: Measured according to JIS K-7234 ICI melt viscosity Measured according to JIS K 7117-2 (ISO 3219)

Synthesis Example 1
In a flask equipped with a thermometer, a condenser, a Dean-Stark azeotropic distillation trap, and a stirrer, 559 parts by mass of aniline and 500 parts by mass of toluene were charged, and 167 parts by mass of 35% hydrochloric acid was dropped over 1 hour at room temperature. After completion of the dropwise addition, the mixture was heated to cool and separate azeotropic water and toluene, and then only the toluene which was the organic layer was returned to the system for dehydration. Subsequently, 251 parts by mass of 4,4′-bis (chloromethyl) biphenyl was added over 1 hour while maintaining at 60 to 70 ° C., and the reaction was further performed at the same temperature for 2 hours. After completion of the reaction, toluene was distilled off while raising the temperature to bring the system to 190 to 200 ° C., and the reaction was carried out at this temperature for 15 hours. After that, 500 parts by weight of a 30% aqueous solution of sodium hydroxide was slowly added dropwise while cooling so that the system was not vigorously refluxed, and the toluene distilled off at 80 ° C. or less was returned to the system and allowed to stand at 70 ° C. to 80 ° C. . The lower aqueous layer separated was removed, and the reaction solution was repeatedly washed with water until the washing solution became neutral. Next, 335 parts by mass of an aniline resin represented by the following formula (8) (softening point 57 ° C., melt viscosity 0.035 Pa · s, amine equivalent 196 g / a) by distilling excess aniline and toluene away from the oil layer under heating and pressure reduction. got eq). Moreover, as a result of measuring by gel permeation chromatography, n in Formula (8) was 1.6 (average value).

(Composition example 2)
In a flask equipped with a stirrer, a reflux condenser, and a stirrer, 59 parts by mass of the aniline resin obtained in Synthesis Example 1, 28 parts by mass of phenol and 90 parts by mass of toluene were added, and the temperature was raised to 60 ° C. Then, 49 parts by mass of an aqueous solution of formaldehyde was added over 60 minutes. Thereafter, the temperature was raised to 80 ° C., and reaction was performed for 8 hours.
After completion of the reaction, 90 parts by mass of toluene was added, and after repeated washing with water, the toluene was distilled off under heating and reduced pressure using a rotary evaporator to obtain 90 parts by mass of benzooxazine resin. The softening point of the obtained benzoxazine resin was 102 ° C., and the melt viscosity was 2.76 Pa · s (150 ° C.).
It was confirmed by ¹ H-NMR analysis that the obtained benzoxazine resin is represented by the following formula (9). The results of ¹ H-NMR analysis are shown in FIG.

(Composition example 3)
In the same manner as in Synthesis Example 1 except that 28 parts by mass of phenol was changed to 34 parts by mass of allylphenol, 98 parts by mass of benzoxazine resin was obtained. The softening point of the obtained benzoxazine resin was 91 ° C., and the melt viscosity was 0.5 Pa · s (150 ° C.).
It was confirmed by ¹ H-NMR analysis that the obtained benzoxazine resin is represented by the following formula (10). The results of ¹ H-NMR are shown in FIG.

(Composition example 4)
In a flask equipped with a thermometer, a condenser, a Dean-Stark azeotropic distillation trap, and a stirrer, 372 parts by mass of aniline and 200 parts by mass of toluene were charged, and 146 parts by mass of 35% hydrochloric acid was added dropwise over 1 hour at room temperature. After completion of the dropwise addition, the mixture was heated to cool and separate azeotropic water and toluene, and then only the toluene which was the organic layer was returned to the system for dehydration. Then, 125 parts by mass of 4,4′-bis (chloromethyl) biphenyl was added over 1 hour while maintaining at 60 to 70 ° C., and reaction was further performed at the same temperature for 2 hours. After completion of the reaction, toluene was distilled off while raising the temperature to bring the system to 195 to 200 ° C., and the reaction was carried out at this temperature for 15 hours. After that, 330 parts by mass of a 30% aqueous solution of sodium hydroxide is slowly added dropwise while cooling so that the system does not vigorously reflux, and the toluene distilled off at the temperature rise below 80 ° C is returned to the system, and at 70 ° C to 80 ° C. Let stand. The lower aqueous layer separated was removed, and the reaction solution was repeatedly washed with water until the washing solution became neutral. Subsequently, 173 parts by mass of an aromatic aniline resin was obtained by distilling off excess aniline and toluene under heating and reduced pressure (200 ° C., 0.6 KPa) from the oil layer using a rotary evaporator. The diphenylamine in the aromatic aniline resin (a1) was 2.0%.
The obtained resin was again added dropwise little by little with a rotary evaporator under heating and reduced pressure (200 ° C., 4 KPa) instead of steam blowing. As a result, 166 parts by mass of an aromatic aniline resin (a1) was obtained. The softening point of the obtained aromatic aniline resin (a1) was 56 ° C., the melt viscosity was 0.035 Pa · s (150 ° C.), and the diphenylamine was 0.1% or less.

(Composition example 5)
In a flask equipped with a thermometer, a condenser, a Dean-Stark azeotropic distillation trap, and a stirrer, 147 parts by mass of maleic anhydride and 300 parts by mass of toluene are charged and heated to azeotropically cool water and toluene After that, only toluene which is an organic layer was returned to the system for dehydration. Next, a resin solution prepared by dissolving 195 parts by mass of the aromatic aniline resin (a1) obtained in Synthesis Example 4 in 195 parts by mass of N-methyl-2-pyrrolidone is kept for 1 hour while maintaining the inside of the system at 80 to 85 ° C. It dripped over. After completion of the dropwise addition, the reaction is carried out at the same temperature for 2 hours, 3 parts by mass of p-toluenesulfonic acid is added, and the condensed water and toluene which are azeotroped under reflux conditions are cooled and separated to obtain toluene as an organic layer. The reaction was carried out for 20 hours while dehydrating the solution. After completion of the reaction, 120 parts by mass of toluene was added and water washing was repeated to remove p-toluenesulfonic acid and excess maleic anhydride, and heating was performed to remove water from the system by azeotropic distillation. Then, the reaction solution was concentrated to obtain 281 parts by mass of solid maleimide resin (A1). The softening point of the obtained maleimide resin was 108 ° C.

Example 1
45 parts by mass of the benzoxazine resin obtained in Synthesis Example 2 and 54 parts by mass of maleimide resin (manufactured by KAI / AI Kasei Co., Ltd., product name: BMI) are blended, and after kneading at 150 ° C., a curing catalyst is obtained One part by weight of 18% Octopus Zn (manufactured by Hope Pharmaceutical Co., Ltd.) was added and cured under the curing conditions of 200 ° C. × 2 hours to obtain a cured product of the present invention. The measurement results of the physical properties of the cured product are shown in Table 1.

(Example 2)
A cured product of the present invention was obtained in the same manner as Example 1, except that the maleimide resin (manufactured by KAI / AI Kasei Co., Ltd. product name: BMI) was changed to the maleimide resin obtained in Synthesis Example 5. The measurement results of the physical properties of the cured product are shown in Table 1.

(Example 3)
A cured product of the present invention was obtained in the same manner as in Example 1 except that the benzoxazine resin obtained in Synthesis Example 2 was changed to the benzoxazine resin obtained in Synthesis Example 3. The measurement results of the physical properties of the cured product are shown in Table 1.

(Example 4)
55 parts by mass of the benzoxazine resin obtained in Synthesis Example 2 and 44 parts by mass of maleimide resin (manufactured by KAI / AI Kasei Co., Ltd., product name: BMI) are blended, and after kneading at 150 ° C., a curing catalyst is obtained One part by weight of 18% Octopus Zn (manufactured by Hope Pharmaceutical Co., Ltd.) was added and cured under the curing conditions of 200 ° C. × 2 hours to obtain a cured product of the present invention. The measurement results of the physical properties of the cured product are shown in Table 1.

(Example 5)
A cured product of the present invention was prepared in the same manner as in Example 4 except that the curing catalyst was changed from 18% Octopus Zn (manufactured by Hope Pharmaceuticals Co., Ltd.) to 2-ethyl 4-methylimidazole (manufactured by Shikoku Kasei Co., Ltd.). Obtained. The measurement results of the physical properties of the cured product are shown in Table 1.

(Example 6)
55 parts by mass of the benzoxazine resin obtained in Synthesis Example 2 and 45 parts by mass of maleimide resin (manufactured by KAI / AI Kasei Co., Ltd., product name: BMI) are blended, and after kneading at 150 ° C., 200 ° C. × 2 It was cured under the curing conditions of time + 230 ° C. × 2 hours to obtain a cured product of the present invention. The measurement results of the physical properties of the cured product are shown in Table 1.

(Example 7)
55 parts by mass of the benzoxazine resin obtained in Synthesis Example 2 and 45 parts by mass of bis-3-ethyl-5-methyl-4-maleimidophenylmethane (manufactured by Kei Ikasei Co., Ltd., product name: BMI-70) After blending in parts and kneading at 150 ° C., curing was carried out under the curing conditions of 200 ° C. × 2 hours + 230 ° C. × 2 hours to obtain a cured product of the present invention. The measurement results of the physical properties of the cured product are shown in Table 1.

(Example 8)
55 parts by mass of the benzoxazine resin obtained in Synthesis Example 2, 2,2′-bis- [4- (4-maleimidophenoxy) phenyl] propane (manufactured by KAI / AI KASEI CO., LTD., Product name: BMI-80) 45 parts by mass of K) were kneaded at 150 ° C., and then cured under the curing conditions of 200 ° C. × 2 hours + 230 ° C. × 2 hours to obtain a cured product of the present invention. The measurement results of the physical properties of the cured product are shown in Table 1.

(Example 9)
50 parts by mass of the benzoxazine resin obtained in Synthesis Example 2, 50 parts by mass of the maleimide resin obtained in Synthesis Example 5, 0.5 parts by mass of 18% Octopus Zn (manufactured by Hope Pharmaceutical Co., Ltd.), 100 parts by mass of MEK Parts were added and the mixture was stirred under reflux at 30 ° C. to form a varnish of the present invention. The obtained varnish was impregnated into glass cloth (product name: 1031 NT-105, manufactured by Arisawa Mfg. Co., Ltd.), dried in an oven at 80 ° C., and additionally dried at 150 ° C. to obtain a prepreg of the present invention. Four sheets of the obtained prepreg are laminated and sandwiched between copper foils (product name: CF-T9FZ-HTE-18, manufactured by Fukuda Metal Foil Division Co., Ltd.), and subjected to 200 ° C × 2 hours + 230 ° C × 2 hours vacuum press It was cured under the curing conditions of the above to obtain a copper-clad laminate of the present invention. The obtained copper-clad laminate was attached to a 25% iron (III) chloride solution to obtain a laminate in which the copper-clad laminate was dissolved. The obtained laminate was subjected to an acid resistance test, an alkali resistance test and an etching grade test for a desmear solution. The results are shown in Table 2.

(Example 10)
10 parts by mass of the benzoxazine resin obtained in Synthesis Example 2, 30 parts by mass of the maleimide resin obtained in Synthesis Example 5, 2,2-bis (4-cyanatophenyl) propane (manufactured by Tokyo Chemical Industry Co., Ltd.) 60 parts by mass) were mixed while heating and melting at 120 ° C. to obtain a benzoxazine-maleimido-cyanate ester resin composition. MDSC measurement was performed to confirm the curing behavior of the obtained resin composition. The results of the MDSC measurement are shown in FIG.
Further, the obtained resin composition was transfer molded under the conditions of 200 ° C. and a molding pressure of 50 kg / cm ² , and the molded body was post-cured at 220 ° C. to obtain a cured product of the present invention. The measurement results of the physical properties of the cured product are shown in Table 3.

(Comparative example 1)
A cured product was obtained in the same manner as in Example 4, except that the benzoxazine resin obtained in Synthesis Example 2 was changed to a bisphenol F-type benzoxazine resin (manufactured by Shikoku Kasei Co., Ltd.). The measurement results of the physical properties of the cured product are shown in Table 1.

(Comparative example 2)
65 parts by mass of bisphenol A type epoxy resin (product name: JER-828, manufactured by Mitsubishi Chemical Corporation), 50 parts by mass of phenol novolac (product name: H-1, manufactured by Meiwa Kasei Co., Ltd.), 2-ethyl 0.5 parts by mass of -4-methylimidazole (manufactured by Shikoku Kasei Co., Ltd.), 70 parts by mass of MEK and 30 parts by mass of methyl cellosolve were added, and the mixture was stirred under reflux at 30 ° C. to prepare a varnish. The varnish was impregnated into glass cloth (product name: 1031 NT-105, manufactured by Arisawa Seisakusho Co., Ltd.), dried in an oven at 80 ° C., and additionally dried at 150 ° C. to obtain a prepreg. Four sheets of the obtained prepreg are laminated and sandwiched between copper foils (product name: CF-T9FZ-HTE-18, manufactured by Fukuda Metal Foil Division Co., Ltd.), and subjected to 200 ° C × 2 hours + 230 ° C × 2 hours vacuum press It hardened on the hardening conditions of, and obtained the copper-clad laminate board. The obtained copper-clad laminate was attached to a 25% iron (III) chloride solution to obtain a laminate in which the copper-clad laminate was dissolved. The obtained laminate was subjected to the acid resistance test, the alkali resistance test, and the etching grade measurement for the desmear solution. The results are shown in Table 2.

(Comparative example 3)
50 parts by mass of bisphenol F-type benzoxazine resin (manufactured by Shikoku Kasei Co., Ltd.), 50 parts by mass of the maleimide resin obtained in Synthesis Example 5 and 100 parts by mass of MEK were added and dissolved under reflux at 30 ° C. It was not.

(Comparative example 4)
33 parts by mass of the maleimide resin obtained in Synthesis Example 5 and 67 parts by mass of 2,2-bis (4-cyanatophenyl) propane (manufactured by Tokyo Chemical Industry Co., Ltd.) are added, and the mixture is heated and melted at 120 ° C. It mixed and obtained mixed resin. MDSC measurements were performed to confirm the curing behavior of the resulting mixed resin. The results of the MDSC measurement are shown in FIG.
Further, the obtained mixed resin was transfer-molded at 200 ° C. under a molding pressure of 50 kg / cm ² , and the molded body was post-cured at 220 ° C. to obtain a cured product. Physical properties of the obtained cured product were evaluated. The results are shown in Table 3.

(Comparative example 5)
The MDSC measurement of 2,2-bis (4-cyanatophenyl) propane (manufactured by Tokyo Chemical Industry Co., Ltd.) was performed to confirm the curing behavior. The results of the MDSC measurement are shown in FIG.

The obtained cured product was measured under the following conditions.
<Heat resistance>
-Measurement of Tg (temperature at maximum of tan δ) was performed by DMA measurement.
Measuring device: Dynamic viscoelasticity measuring instrument TA-instruments, Q-800
Measurement temperature: 30 to 350 ° C
Heating rate: 2 ° C / min
Sample size: Width 5 mm × length 50 mm × thickness 0.8 mm
<Dielectric constant and dielectric loss tangent>
-Measurement was performed by a cavity resonator perturbation method using a cavity resonator.
Measurement device: Cavity resonator Agilent Technologies, Inc. Measurement method: Measurement at 1 GHz according to JIS K6991 Measurement mode: Cavity resonator perturbation method Measurement temperature: 25 ° C.
Sample size: Width 1.7mm × length 100mm × thickness 1.7mm
<Heat resistant decomposition resistance>
TG-DTA was used to measure the temperature at which the weight was reduced by 1% and 5%.
Measuring device: TG-DTA6220 manufactured by SII Measuring temperature: 30 to 580 ° C.
Heating rate: 10 ° C / min
Td 1: 1% weight loss temperature Td 5: 5% weight loss temperature <water absorption>
・ Weight gain (%) after boiling test piece in water at 100 ° C for 24 hours
Sample size: 5 cm diameter × 4 mm thick disc

The obtained laminate was measured under the following conditions.
<Acid resistance test>
· Adjust hydrochloric acid specified in JIS K 8576 to an aqueous solution with a concentration of 3 ± 0.2 wt% and a temperature of 40 ± 2 ° C, immerse the sample for 24 hours, remove it, and immediately wash in running water for 20 ± 10 minutes, Check for swelling or discoloration of the dry, clean sample.
<Alkali resistance test>
-Adjust sodium hydroxide specified in JIS K 8576 to an aqueous solution with a concentration of 3 ± 0.2 wt% and a temperature of 40 ± 2 ° C, immerse the sample for 24 hours, and then immediately take out it for 20 ± 10 minutes in running water. Check the washed and dried clean sample for swelling and discoloration.
<Etching grade test for desmear liquid>
· After swelling the test pieces cut into 10 cm × 10 cm after drying in the “OPC-1080 conditioner” and “electroless copper R-N” manufactured by Okuno Pharmaceutical Co., Ltd. for 5 minutes at 60 ° C. for 5 minutes, Micro etching was performed at 80 ° C. for 6 minutes using “OPC-1200 EVO Etch” and “OPC-1540 MN” manufactured by Pharmaceutical Co., Ltd. Next, after neutralizing for 5 minutes with Okuno Seiyaku Co., Ltd. “OPC-1300 Neutriizer”, it is dried at 100 ° C. for 24 hours, then air cooled in a desiccator for 1 day, and then the mass after desmear treatment is measured. did. The resistance to desmear liquid was calculated from (weight change / surface area of sample).

<Yield of transfer molded product>
A cured resin molding was produced under the following transfer molding conditions.
The yield was evaluated by (number of samples without cracks) / (number of samples).
Heating temperature: 200 ° C
Molding pressure: 50 kg / cm ²
Sample shape: Width 1.7mm × length 100mm × thickness 1.7mm

The curing behavior of the resin composition obtained in Example 10 and Comparative Examples 4 and 5 was measured under the following conditions.
<Hardening behavior>
The heat of curing was observed by MDSC measurement.
Measuring device: Q-2000 TA Instruments Co. Measuring temperature: 25 to 330 ° C
Heating rate: 3 ° C / min
Measurement mode: MDSC measurement

Tg 1st: First measurement result Tg 2nd: After completion of the first measurement, the sample heated to 350 ° C. is cooled to room temperature and re-measured result ΔTg: (Tg 2nd)-(Tg 1st)

From the results of Table 1, Comparative Example 1 was good in heat resistance, but failed in other characteristics. On the other hand, the curable resin compositions (Examples 1 to 8) of the present invention showed excellent results in all of the heat resistance, thermal decomposition characteristics, dielectric characteristics, and water absorption characteristics.

Comparative Example 3 did not dissolve in MEK generally used in the field of substrates, whereas Example 9 had good solubility in MEK and was excellent in processability to laminates.

From the results of Table 2, Example 9 was excellent in chemical resistance, and showed a result of being more excellent in the resistance to desmear liquid than Comparative Example 2 which is a general epoxy laminate.

From the results of FIG. 3, although Comparative Examples 4 and 5 have a high polymerization temperature, Example 10 adds a benzoxazine resin of the present invention, although a cyanate ester resin is not added. And promoting the polymerization of the maleimide resin.
Furthermore, from the results in Table 3, it was confirmed that the benzoxazine-maleimido-cyanate ester resin composition of the present invention hardly causes a change in ΔTg and cures under the condition of 220 ° C.
Moreover, the cured product was excellent in heat resistance and showed excellent results as compared with the composition of BT resin known as a low dielectric material.
Since Example 10 is cured without a catalyst and is excellent in heat resistance and low dielectric property, industrial applicability is high.

Although the present invention has been described in detail with reference to particular embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.
This application is based on the Japanese Patent Application (Japanese Patent Application No. 2017-203286) filed on October 20, 2017, which is incorporated by reference in its entirety. Also, all references cited herein are taken as a whole.

The curable resin composition of the present invention is excellent in solvent solubility, and a cured product excellent in heat resistance, thermal decomposition characteristics, dielectric characteristics, water absorption characteristics, and chemical resistance can be obtained. It is useful for sealing material applications, laminates (printed wiring boards, build-up substrates, etc.), various composite materials including CFRP, adhesives, paints, etc.

Claims (9)

1. Curable resin composition containing maleimide resin (A) and benzoxazine resin (B) represented by following formula (1).
   

   

   (In formula (1), n is an average value of the number of repetitions and represents a real number of 1 to 10. R ₁ to R ₈ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group _{If .R} 3 ~ _{R 7} represent either a group is present in plural, each of _R 3 ~ _{R 7} is optionally being the same or different _{.R 9, R 10} each independently represent a hydrogen atom Or an alkyl group having 1 to 8 carbon atoms, an aryl group, an allyl group or an alkoxy group, and when a plurality of R _{9 s} and R _{10 s} are present, each R _{9 s} and R _{10 s} may be identical to each other The dotted line may indicate that a benzene ring may be formed.)
2. The curable resin composition according to claim 1, wherein R ₁ to R ₈ in the formula (1) are hydrogen atoms.
3. The curable resin composition according to claim 1, wherein the maleimide resin (A) contains one or more resins selected from an aromatic maleimide resin and an aliphatic maleimide resin.
4. The curable resin composition according to any one of claims 1 to 3, further comprising a cyanate ester resin.
5. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 4.
6. The varnish which melt | dissolved the curable resin composition as described in any one of Claims 1-4 in the solvent.
7. A prepreg obtained by impregnating the varnish according to claim 6 into a substrate.
8. A cured product obtained by curing the prepreg according to claim 7.
9. A laminated board or a copper clad laminated board obtained by using the prepreg according to claim 7.

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