Benzoxazine resin composition

Abstract

The objective of this invention is to provide a resin material using a benzoxazine compound that exhibits excellent heat resistance and dielectric properties. As a solution, a benzoxazine resin composition is provided, characterized by comprising a resin component (A) and a resin component (B), wherein resin component (A) is a benzoxazine compound represented by general formula (1); and resin component (B) is an epoxy resin having a cyclic aliphatic structure; [Chemical 1] wherein R1 independently represents an alkylene group having 1 to 4 carbon atoms, and X represents a cycloalkane group having 5 to 20 carbon atoms.

Description

Technical Field

[0001] This invention relates to a benzoxazine resin composition. More specifically, it relates to a curable benzoxazine resin composition comprising a benzoxazine compound having benzoxazine rings at both ends of a cycloalkane group, further having allyl groups, and an epoxy resin. Background Technology

[0002] Benzoxazine compounds are synthesized by reacting phenols, amines and formaldehyde. They are known as thermosetting resins that are cured by ring-opening polymerization of benzoxazine rings without producing volatile byproducts due to heating. They are used as raw materials for molding materials for insulating substrates, liquid crystal alignment agents, resin compositions for semiconductor sealing, adhesives, potting materials, laminating materials, coating materials, paints and coatings.

[0003] In this application, excellent heat resistance with stability or reliability at high temperatures is sought.

[0004] On the other hand, there are still issues related to heat resistance, such as the lack of heat resistance above 200°C. Allyl-containing benzoxazine compositions have been reported to address this issue (Patent Document 1). While Patent Document 1 describes allyl-containing benzoxazine resins and allyl-containing naphthoxazine resins as resin compositions using epoxy resins, phenolic resins, melamine resins, etc., the specific physical properties of the resulting cured products are not yet clearly defined.

[0005] Patent documents Patent Document 1: Japanese Patent Application Publication No. 2003-286320 Summary of the Invention Regarding the applications of benzoxazine compounds, there is a need for a material that possesses both excellent heat resistance and excellent dielectric properties, particularly for use in electrical and electronic equipment components such as printed circuit boards, semiconductors, or sealants for electronic components.

[0006] The objective of this invention is to provide a resin material using a benzoxazine compound that has excellent heat resistance and dielectric properties.

[0007] The inventors conducted in-depth research to solve the above-mentioned problems and found that the cured product obtained by using cycloalkane-based bisphenols as raw materials and a resin composition containing a benzoxazine compound having benzoxazine rings at both ends of the cycloalkane-based groups and further having allyl groups, and an epoxy resin having a cyclic aliphatic structure, is a resin material with excellent heat resistance and dielectric properties, thus completing the present invention.

[0008] The present invention is as follows.

[0009] 1. A benzoxazine resin composition, characterized in that it contains resin component (A) and resin component (B). Resin component (A): benzoxazine compounds represented by general formula (1); Resin component (B): Epoxy resin with a cyclic aliphatic structure; [Chemistry 1]

[0010] In the formula, R1 independently represents an alkylene group with 1 to 4 carbon atoms, and X represents a cycloalkane group with 5 to 20 carbon atoms.

[0011] 2. The benzoxazine resin composition according to 1, characterized in that X in the general formula (1) is selected from at least one of cyclohexylene, 3-methylcyclohexylene, 4-methylcyclohexylene, 3,3,5-trimethylcyclohexylene and cyclododecylene.

[0012] 3. The benzoxazine resin composition according to 1, characterized in that the content of the resin component (A) relative to the total amount of the resin components is in the range of 1% by weight or more and 99% by weight or less.

[0013] 4. The benzoxazine resin composition according to 1, characterized in that the resin component (B) is selected from at least one of cycloalkylidene bisphenol type epoxy resin, dicyclopentadiene type epoxy resin, and alicyclic epoxy resin.

[0014] 5. The benzoxazine resin composition according to 1, characterized in that it further contains component (D). Ingredient (D): Curing accelerator.

[0015] 6. A cured product, characterized in that it is a cured product of the benzoxazine resin composition described in 1.

[0016] The benzoxazine resin composition of the present invention yields cured products with excellent heat resistance and dielectric properties. Therefore, it is particularly useful as a resin material for electrical and electronic equipment such as printed circuit boards, semiconductors, or electronic components, serving as a sealant. Attached Figure Description

[0017] Figure 1 This represents the benzoxazine compound represented by formula (1-4) obtained in Synthetic Example 1. 1 The spectrum obtained by H NMR analysis.

[0018] Figure 2 This represents the benzoxazine compound represented by formula (1-5) obtained in Synthetic Example 2. 1 The spectrum obtained by H NMR analysis. Detailed Implementation

[0019] <Benzoxazine Resin Composition> The benzoxazine resin composition of the present invention contains a benzoxazine compound represented by general formula (1) as resin component (A) and an epoxy resin as resin component (B).

[0020] <Resin component (A): Benzooxazine compounds represented by general formula (1)> The resin component (A) in the benzoxazine resin composition of the present invention is a benzoxazine compound represented by general formula (1).

[0021] [Chemistry 2]

[0022] (In the formula, R1 independently represents an alkylene group with 1 to 4 carbon atoms, and X represents a cycloalkane group with 5 to 20 carbon atoms.) In general formula (1), R1 is each independently an alkylene group having 1 to 4 carbon atoms, preferably an alkylene group having 1 or 2 carbon atoms, more preferably methylene or 1,2-ethylene, and particularly preferably methylene.

[0023] In general formula (1), X represents a cycloalkane group with 5 to 20 carbon atoms. It may also contain an alkyl group as a branch, in which case the number of carbon atoms of the branched alkyl group is also included in the number of carbon atoms of 5 to 20. The cycloalkane group is preferably 5 to 15 carbon atoms, more preferably 6 to 12 carbon atoms, even more preferably 6 to 10 carbon atoms, and particularly preferably 6 to 9 carbon atoms.

[0024] As cycloalkylidenes, specifically, examples include: cyclopentylidene (5 carbon atoms), cyclohexylidene (6 carbon atoms), 3-methylcyclohexylidene (7 carbon atoms), 4-methylcyclohexylidene (7 carbon atoms), 3,3,5-trimethylcyclohexylidene (9 carbon atoms), cycloheptylidene (7 carbon atoms), bicyclo[2.2.1]heptane-2,2-diyl (7 carbon atoms), 1,7,7-trimethylbicyclo[2.2.1]heptane-2,2-diyl (10 carbon atoms), 4,7,7-trimethylbicyclo[2.2.1]heptane-2,2-diyl (10 carbon atoms), tricyclo[5.2.1.0]heptane-2,2-diyl (10 carbon atoms), tricyclo[5.2.1.0]heptane-2,2-diyl (10 carbon atoms), and tricyclo[5.2.1.0]heptane-2,2-diyl (10 carbon atoms). 2,6Decane-8,8-diyl (10 carbon atoms), 2,2-adamantane-idel (10 carbon atoms), cyclododecane-idel (12 carbon atoms), etc. are preferred. Cyclohexidel (6 carbon atoms), 3-methylcyclohexidel (7 carbon atoms), 4-methylcyclohexidel (7 carbon atoms), 3,3,5-trimethylcyclohexidel (9 carbon atoms), or cyclododecane-idel (12 carbon atoms) are more preferred, 3-methylcyclohexidel (7 carbon atoms), 4-methylcyclohexidel (7 carbon atoms), 3,3,5-trimethylcyclohexidel (9 carbon atoms), or cyclododecane-idel (12 carbon atoms) are even more preferred, and 3,3,5-trimethylcyclohexidel (9 carbon atoms) is particularly preferred.

[0025] As a specific example of a benzoxazine compound represented by general formula (1), compounds represented by chemical formulas (1-1) to (1-20) are shown. Preferably, at least one of compounds (1-1) to (1-5) and compounds (1-11) to (1-15) is selected, more preferably at least one of compounds (1-1), (1-4), (1-5), (1-11), (1-14) and (1-15) is selected, even more preferably at least one of compounds (1-4), (1-5), (1-14) and (1-15) is selected, and particularly preferably at least one of compounds (1-4) and (1-14) is selected.

[0026] [Chemistry 3]

[0027] [Chemistry 4]

[0028] [Chemistry 5]

[0029] The benzoxazine compound represented by general formula (1) can be stored for a long time at room temperature and has good storage stability compared with the benzoxazine compound represented by the previously known formula (i). Therefore, it is easier to store and operate in industrial production as a raw material for manufacturing the benzoxazine resin composition of the present invention.

[0030] <Method for manufacturing benzoxazine compounds represented by general formula (1)> With regard to the benzoxazine compound represented by general formula (1) in this invention, there are no particular limitations on the starting materials or manufacturing methods used in its production. For example, a method for producing the benzoxazine compound represented by the target general formula (1) can be cyclized by subjecting a bisphenol compound represented by general formula (2) to a dehydration condensation reaction with an amine compound represented by general formula (3) and formaldehyde, as illustrated in the following reaction formula.

[0031] [Chemistry 6]

[0032] (In the formula, R1 and X are defined in the same way as in general formula (1).) In the above manufacturing method, bisphenol compounds represented by general formula (2), amine compounds represented by general formula (3) and formaldehydes are used as starting materials.

[0033] Specifically, examples of bisphenol compounds represented by general formula (2) include: bisphenol Z (1,1-bis(4-hydroxyphenyl)cyclohexane), 1,1-bis(4-hydroxyphenyl)-3-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-4-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis(4-hydroxyphenyl)cyclododecane, 2,2-bis(4-hydroxyphenyl)bicyclo[2.2.1]heptane, 2,2-bis(4-hydroxyphenyl)-1,7,7-trimethylbicyclo[2.2.1]heptane, 2,2-bis(4-hydroxyphenyl)-4,7,7-trimethylbicyclo[2.2.1]heptane, 4,4'-(tricyclo[5.2.1.0]heptane, etc. 2,6 Decane-8,8-diyl)bisphenol, 2,2-bis(4-hydroxyphenyl)adamantane, etc. are preferred. Among them, bisphenol Z (1,1-bis(4-hydroxyphenyl)cyclohexane), 1,1-bis(4-hydroxyphenyl)-3-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-4-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane or 1,1-bis(4-hydroxyphenyl)cyclododecane are preferred, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane or 1,1-bis(4-hydroxyphenyl)cyclododecane are more preferred, and 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane is particularly preferred.

[0034] As an amine compound represented by general formula (3), examples include, for instance, allylamine, 3-buten-1-amine, and 4-penten-1-amine. Allylamine is preferred.

[0035] The amine compound represented by general formula (3) can also be used as a salt with inorganic acids such as hydrochloric acid and sulfuric acid. In this case, the reaction can be carried out in the presence of an alkaline aqueous solution obtained by dissolving sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, etc. in water.

[0036] As for formaldehyde, examples include formaldehyde aqueous solution, trioxymethylene, paraoxymethylene, etc.

[0037] In the above manufacturing method, the amount of formaldehyde used, converted into the amount of formaldehyde participating in the synthesis reaction of benzoxazine compound (A), is preferably in the range of 4.0 to 20.0 moles relative to 1 mole of bisphenol compound represented by general formula (2), more preferably in the range of 4.0 to 16.0 moles, and even more preferably in the range of 4.0 to 12.0 moles.

[0038] In the above manufacturing method, the amount of amine compound used as represented by general formula (3) is preferably in the range of 2.0 to 10.0 moles relative to 1 mole of bisphenol compound represented by general formula (2), more preferably in the range of 2.0 to 8.0 moles, and even more preferably in the range of 2.0 to 6.0 moles.

[0039] For example, 1 mole of trioxymethylene participates in the reaction as 3 moles of formaldehyde.

[0040] A catalyst to promote the reaction is not particularly required, but acid or base catalysts can be used as needed. Examples of usable acid catalysts include concentrated hydrochloric acid, hydrogen chloride gas, trifluoroacetic acid, methanesulfonic acid, p-toluenesulfonic acid, benzoic acid, and mixtures thereof. Examples of usable base catalysts include sodium hydroxide, sodium carbonate, triethylamine, triethanolamine, and mixtures thereof, but the reactions are not limited to these. P-Toluenesulfonic acid and sodium hydroxide are preferred, with sodium hydroxide being more preferred.

[0041] The reaction is usually carried out in the presence of a solvent. There are no particular restrictions on the solvent as long as it does not hinder the reaction. Preferred solvents include aromatic hydrocarbons with 6 to 9 carbon atoms such as toluene and xylene; aliphatic alkyl compounds with 5 to 8 carbon atoms such as hexane, heptane, and cyclohexane; aliphatic esters with 3 to 6 carbon atoms such as methyl acetate, ethyl acetate, methyl propionate, and butyl acetate; and water. More preferably, aromatic hydrocarbons with 6 to 9 carbon atoms and aliphatic esters with 3 to 6 carbon atoms are preferred, and even more preferably, aliphatic esters with 3 to 6 carbon atoms are preferred. These solvents can be used alone or in combination. Furthermore, there are no particular restrictions on the amount of solvent used as long as it does not hinder the reaction. Generally, it is preferred to be in the range of 200 to 400 parts by weight relative to 100 parts by weight of the bisphenol compound represented by general formula (2), and more preferably in the range of 250 to 300 parts by weight.

[0042] The reaction temperature is generally preferred to be in the range of 30 to 100°C, more preferably in the range of 30 to 80°C, and particularly preferably in the range of 40 to 70°C.

[0043] The reaction can be carried out under normal pressure, or under pressure or pressure.

[0044] There are no restrictions on the method of mixing the bisphenol compound represented by general formula (2), formaldehyde, and amine compound represented by general formula (3) as raw materials. For example, the following methods can be listed: (A) a method of reacting the amine compound represented by general formula (3) with a mixture containing the bisphenol compound represented by general formula (2) and formaldehyde; (B) a method of mixing the bisphenol compound represented by general formula (2) with a mixture containing formaldehyde and amine compound represented by general formula (3). These mixtures may contain the above-mentioned solvent or catalyst, and there are no restrictions on the method of mixing the catalyst. It is preferable to mix the catalyst before mixing the amine compound represented by general formula (3).

[0045] In the manufacturing method of the present invention, there is no limitation on the method of mixing the remaining raw materials with the mixture of raw materials, but from the perspective of reaction selectivity and suppression of the generation of high molecular weight components as by-products, it is preferable to carry out the mixing continuously or intermittently, for example, for 10 minutes to 2 hours, compared with one-time mixing.

[0046] Alternatively, the process may include a step of removing water from the raw materials or water generated during the reaction from the system. There are no particular limitations on the step of removing the generated water from the reaction solution; this can be done by azeotropic distillation of the generated water with a solvent in the reaction solution. The generated water can be removed from the reaction system, for example, using an isobaric dropping funnel with a stopcock, a Deutsche condenser, or a Dean-Stark apparatus.

[0047] Regarding the resulting reaction mixture, the benzoxazine compound represented by general formula (1) can be obtained from the mixture by known methods after the reaction. For example, the reaction mixture can be deactivated by the catalyst used or washed with water after the reaction, or the target compound can be obtained in the form of a residue by distilling off residual feedstock or solvent from the reaction mixture. Alternatively, the residue can be added to a poor solvent to obtain a precipitated target compound, or a solvent can be added to the reaction mixture for crystallization, followed by filtration to obtain a powder or granular target compound. The benzoxazine compound obtained by the above methods can be purified to a high purity product by conventional purification methods such as washing with solvent or water or recrystallization.

[0048] The benzoxazine compound represented by general formula (1) may contain compounds that are byproducts of the reaction in which it is manufactured. Examples of such byproducts include compounds with higher molecular weights than the benzoxazine compound represented by general formula (1).

[0049] The purity of the benzoxazine compound represented by general formula (1) is not particularly limited. Its purity can be analyzed by gel permeation chromatography with a differential refractometer as the detector. Generally, it is in the range of 10 to 100 area% relative to the area of ​​all peaks detected in the analysis, preferably in the range of 20 to 100 area%, more preferably in the range of 40 to 100 area%, and particularly preferably in the range of 60 to 100 area%.

[0050] <Resin component B: Epoxy resin with a cyclic aliphatic structure> The resin component (B) in the benzoxazine resin composition of the present invention is an epoxy resin having a cyclic aliphatic structure. Examples of epoxy resins having this cyclic aliphatic structure include cycloalkylidene bisphenol type epoxy resins, dicyclopentadiene type epoxy resins, and alicyclic epoxy resins; preferably, at least one selected from these is used. Among these, at least one selected from cycloalkylidene bisphenol type epoxy resins and dicyclopentadiene type epoxy resins is more preferred, and dicyclopentadiene type epoxy resins are particularly preferred.

[0051] (Cycloalkylidene bisphenol type epoxy resin) As a cycloalkane-based bisphenol type epoxy resin, specifically, for example, compounds represented by the following formulas can be listed.

[0052] [Chemistry 7]

[0053] (Dicyclopentadiene type epoxy resin) Examples of dicyclopentadiene-type epoxy resins include compounds represented by the following formulas.

[0054] [Chemistry 8]

[0055] Commercially available products of dicyclopentadiene type epoxy resins include, for example, “EPICLON” HP7200, “EPICLON” HP7200L, “EPICLON” HP7200H (manufactured by DIC Corporation), “Tactix” (registered trademark) 558 (manufactured by Huntsman Advanced Materials), and XD-1000 (manufactured by Nippon Kayaku Co., Ltd.).

[0056] (Alicyclic epoxy resin) Examples of alicyclic epoxy resins include methyl 3,4-epoxycyclohexylcarboxylate, 3,4-epoxycyclohexylcarboxylate, 1-methyl-4-(2-methylepoxyethylene)-7-oxabicyclo[4.1.0]heptane, limonene dioxide, 1,2-epoxy-4-vinylcyclohexane, or compounds represented by the following formulas.

[0057] [Chemistry 9]

[0058] Commercially available products of 3,4-epoxycyclohexylcarboxylic acid-3',4'-epoxycyclohexylmethyl ester include, for example: "CELLOXIDE" (registered trademark, hereinafter the same) 2021P (made by Daicel Co., Ltd.) and CY179 (made by Huntsman Advanced Materials Co., Ltd.).

[0059] <Resin component C: Other benzoxazine compounds> The benzoxazine resin composition of the present invention may contain benzoxazine compounds other than those represented by general formula (1) (hereinafter sometimes referred to as "other benzoxazine compounds") as resin component (C), provided that the effects of the present invention are not significantly impaired. Other benzoxazine compounds may include, for example, benzoxazine compounds that do not contain benzoxazine compounds represented by general formula (1) but have the structures represented by general formulas (A) to (C).

[0060] [Chemistry 10]

[0061] (In the formula, Ra represents a divalent group with 1 to 30 carbon atoms, Rb represents a monovalent group with 1 to 10 carbon atoms that can have substituents, and n represents 0 or 1 independently.) [Chemistry 11]

[0062] (In the formula, Rc represents a divalent group, direct bond, oxygen atom, sulfur atom, carbonyl group or sulfonyl group with 1 to 30 carbon atoms, and Rd independently represents a monovalent group with 1 to 10 carbon atoms.) [Chemistry 12]

[0063] (In the formula, Re independently represents a monovalent group with 1 to 10 carbon atoms, and m represents 0 or 1.) In benzoxazine compounds having the structure represented by general formula (A), Ra represents a divalent group having 1 to 30 carbon atoms. Specific examples include: alkylene compounds such as 1,2-ethylene, 1,4-butylene, and 1,6-hexene; alkylene compounds containing cyclic structures such as 1,4-cyclohexene, dicyclopentadienylene, and adamantylene; and aryl compounds such as 1,4-phenylene, 4,4'-biphenylene, diphenyl ether-4,4'-diyl, diphenyl ether-3,4'-diyl, benzophenone-4,4'-diyl, and diphenyl sulfone-4,4'-diyl.

[0064] In benzoxazine compounds having the structure represented by general formula (A), each Rb independently represents a monovalent group having 1 to 10 carbon atoms. Specific examples include alkyl groups such as methyl, ethyl, propyl, and butyl; alkenyl groups such as vinyl and allyl; alkynyl groups such as ethynyl and propargyl; and aryl groups such as phenyl and naphthyl. These groups may further have substituents such as alkoxy groups having 1 to 4 carbon atoms, acyl groups having 1 to 4 carbon atoms, halogen atoms, carboxyl groups, sulfonyl groups, allyloxy groups, hydroxyl groups, and thiol groups.

[0065] Examples of benzoxazine compounds having the structure represented by general formula (A) include: Pd-type benzoxazine manufactured by Shikoku Chemical Co., Ltd., JBZ-OP100N and JBZ-BP100N manufactured by JFE Chemical Co., Ltd.

[0066] In benzoxazine compounds having the structure represented by general formula (B), Rc represents a divalent group with 1 to 30 carbon atoms, a direct bond, an oxygen atom, a sulfur atom, a carbonyl group, or a sulfonyl group. Examples of divalent groups with 1 to 30 carbon atoms include: alkylene groups such as methylene, 1,2-ethylene, 1,4-butylene, and 1,6-hexene; alkylene groups containing cyclic structures such as 1,4-cyclohexene, dicyclopentadienylene, and adamantylene; and alkylene groups such as ethoxylide, propylene, isopropylene, butylidene, phenylethoxylide, cyclopentoxylide, cyclohexylidene, cycloheptylidene, cyclododecylidene, 3,3,5-trimethylcyclohexylidene, and fluoreneidene.

[0067] In benzoxazine compounds having the structure represented by general formula (B), each Rd independently represents a monovalent group having 1 to 10 carbon atoms. Specific examples include: alkyl groups such as methyl, ethyl, propyl, and butyl; alkenyl groups such as vinyl and allyl; alkynyl groups such as ethynyl and propargyl; and aryl groups such as phenyl and naphthyl. These groups may further have substituents such as alkoxy groups having 1 to 4 carbon atoms, acyl groups having 1 to 4 carbon atoms, halogen atoms, carboxyl groups, sulfonyl groups, allyloxy groups, hydroxyl groups, and thiol groups.

[0068] Examples of benzoxazine compounds having the structure represented by general formula (B) include Fa-type benzoxazine manufactured by Shikoku Chemical Co., Ltd., and BS-BXZ manufactured by Konishi Chemical Co., Ltd.

[0069] In benzoxazine compounds having the structure represented by general formula (C), each Re independently represents a monovalent group having 1 to 10 carbon atoms. Specific examples include: alkyl groups such as methyl, ethyl, propyl, and butyl; alkenyl groups such as vinyl and allyl; alkynyl groups such as ethynyl and propargyl; and aryl groups such as phenyl and naphthyl. These groups may further have substituents such as alkoxy groups having 1 to 4 carbon atoms, acyl groups having 1 to 4 carbon atoms, halogen atoms, carboxyl groups, sulfonyl groups, allyloxy groups, hydroxyl groups, and thiol groups.

[0070] (Amount of resin component used) In the benzoxazine resin composition of the present invention, resin component (A), resin component (B), and resin component (C) are sometimes collectively referred to as resin components.

[0071] In the benzoxazine resin composition of the present invention, the content ratio of resin component (A) relative to the total amount of resin components (resin component (A) and resin component (B), or resin component (A), resin component (B) and resin component (C)) is preferably in the range of 1% to 99% by weight, more preferably in the range of 5% to 95% by weight, further preferably in the range of 10% to 90% by weight, and particularly preferably in the range of 20% to 70% by weight.

[0072] (Component (D)) Although the benzoxazine resin composition of the present invention can be cured by heating alone, it may also contain a curing accelerator as component (D), preferably containing a curing accelerator.

[0073] There are no particular limitations on the curing accelerators that can be used. Examples include: tertiary amines such as 1,8-diazabicyclo[5.4.0]undec-7-ene, triethylenediamine, and tris(2,4,6-dimethylaminomethyl)phenol; imidazoles such as 2-ethyl-4-methylimidazolium and 2-methylimidazolium; phosphorus compounds such as triphenylphosphine, tris(p-tolyl)phosphine, tetraphenylphosphonium bromide, tetraphenylphosphonium tetraphenylborate, and tetra-n-butylphosphonium-O,O-diethyldithiophosphate, quaternary ammonium salts, organometallic salts, and their derivatives. These can be used alone or in combination. Among these curing accelerators, tertiary amines, imidazoles, and phosphorus compounds are preferred.

[0074] In the benzoxazine resin composition of the present invention, the content of component (D) relative to 100 parts by weight of the total amount of resin components is preferably in the range of 0.01 parts by weight to 10 parts by weight, more preferably in the range of 0.05 parts by weight to 5 parts by weight, and even more preferably in the range of 0.1 parts by weight to 5 parts by weight.

[0075] <Ingredient E: Filler> The benzoxazine resin composition of the present invention may further contain component (E) filler.

[0076] As fillers for component (E), inorganic fillers such as silicon dioxide, aluminum oxide, magnesium oxide, boron nitride, aluminum nitride, silicon nitride, and silicon carbide, or reinforcing fibers such as carbon fiber, glass fiber, aramid fiber, nylon fiber, high-strength polyester fiber, boron fiber, and steel fiber can be used.

[0077] In the benzoxazine resin composition of the present invention, the content of component (E) is preferably in the range of 100 parts by weight or more but less than 1,000 parts by weight, and more preferably in the range of 300 parts by weight or more but less than 1,000 parts by weight, relative to the total amount of resin components.

[0078] The method of adding each component used in the benzoxazine resin composition of the present invention is not particularly limited, and conventionally known methods can be used. Examples include: methods of adding during the synthesis or polymerization of polymer materials; methods of adding a resin made of polymer materials, for example, to molten resin in a melt extrusion process; methods of impregnating a resin article made of polymer materials; and methods of uniformly dissolving and dispersing each component in a solvent and evaporating the solvent used.

[0079] Regarding the benzoxazine resin composition of the present invention, if the composition contains water or residual solvent, bubbles will be generated during curing. Therefore, to avoid this situation, vacuum degassing is preferably performed as a pretreatment. The temperature of this vacuum degassing is not particularly limited as long as it brings the benzoxazine resin composition of the present invention to a molten state, but it is preferably performed at an upper limit of 150°C for reasons such as preventing curing and facilitating degassing. The pressure of the vacuum degassing is not particularly limited, but low pressure (high decompression) is preferred, and it can be performed in air or a nitrogen-replaced environment. The vacuum degassing is performed until bubbles are no longer visible to the naked eye.

[0080] <Cure of benzoxazine resin composition> Examples of methods for manufacturing the cured product of the present invention include: heating a benzoxazine resin composition to a certain temperature to cure it; heating and dissolving the resin and then injecting it into a mold, followed by heating the mold to cure it; and injecting a molten material into a preheated mold to cure it.

[0081] The cured product of the present invention can be cured by ring-opening polymerization under the same curing conditions as conventional benzoxazine. The curing temperature is typically in the range of 70 to 300°C, preferably in the range of 100 to 280°C, more preferably in the range of 100 to 260°C, but in order to improve the mechanical properties of the resulting cured product, it is particularly preferred to set it in the range of 100 to 240°C. When curing is carried out within this temperature range, the reaction time is about 1 to 10 hours.

[0082] The benzoxazine resin composition of the present invention is suitable as a resin raw material for varnishes that can be coated on various substrates, prepregs containing impregnated varnishes, copper-clad laminates, printed circuit boards, sealants for semiconductors or electronic components, electrical and electronic molded parts, automotive parts, laminates, coatings, resist inks, etc., and the cured product is suitable as a material resin for them. In particular, the cured product of the benzoxazine resin composition of the present invention is useful as a resin material for prepregs, copper-clad laminates, printed circuit boards, sealants for semiconductors or electronic components, and electrical and electronic molded parts due to its excellent heat resistance and dielectric properties.

[0083] Example The present invention will be further described in detail below through examples.

[0084] <Analytical Methods> 1. Liquid Chromatography (LC) Measurement Apparatus: High Performance Liquid Chromatography (HPLC) System: Prominence UFLC (manufactured by Shimadzu Corporation) Pump: LC-20AD Column oven: CTO-20A Detector: SPD-20A Column: HALO-C18 (3mm inner diameter, 75mm length) Incubator temperature: 50℃ Flow rate: 0.7 mL / min. Detection wavelength: 280nm Mobile phase: (A) 0.2 vol% aqueous acetic acid, (B) tetrahydrofuran Gradient condition: (B) Volume % 0-5min.,10→20% 5-10min.,20% 10-18min.,20→100% 18-22min.,100% 2. Gel permeation chromatography: GPC Device: HLC-8320 / manufactured by Tosoh Corporation Detector: Differential refractometer (RI) [Measurement Conditions] Flow rate: 1 mL / min. Eluent: Tetrahydrofuran Temperature: 40℃ Wavelength: 254nm Sampling interval: 100 seconds. Test sample: A solution of 10 mg of benzoxazine compound diluted 50 times with tetrahydrofuran. Injection volume: 10 μL [Column] (starting from the top) Guard Column HXL-L + G4000HXL + G3000HXL + G2000HXL × 2 pieces (7.8mm ID × 30cm, manufactured by Tosoh Corporation) 3. NMR Analysis Measurement apparatus: Fourier transform nuclear magnetic resonance AVANCE III HD 400 (BRUKER manufactured) The sample was dissolved in deuterated chloroform and the determination was performed. 1 H-NMR spectrum.

[0085] 4. Determination of glass transition temperature (Tg) (Dynamic viscoelasticity determination (DMA)) Device: DMA850 / TA Instruments Japan Co., Ltd. Measurement conditions: 3-point bending Measurement temperature: 30~310℃ Measurement frequency: 1.0 (Hz) Sample dimensions: (60mm × 15mm × 2mm) Heating rate: 1.0℃ / min. 5. Evaluation of dielectric properties Using the apparatus described below, the relative permittivity and dielectric loss tangent of the films (sample size: width 1.5 mm, length 8.0 mm) prepared in the examples and comparative examples were measured.

[0086] Measurement apparatus: PNA network analyzer N522B (manufactured by Keysight Technologies Co., Ltd.) Cavity resonator: CP531 for 10GHz (manufactured by Kanto Electronics Application Development Co., Ltd.) [Measurement Conditions] Test method: According to IEC 62180 (perturbation method for cavity resonators) of the International Electrotechnical Commission. Test conditions: Frequency: 10GHz Number of measurements: n = 2 <Synthetic Example 1> (Synthesis of benzoxazine compounds represented by formulas (1-4)) [Chemistry 13]

[0087] To a 2L four-necked flask equipped with a thermometer, stirrer, cooling tube, and dropping funnel, add 130g (1.3mol) of allylamine hydrochloride. While stirring and monitoring the temperature rise, slowly add 110g (1.3mol) of 48% NaOH aqueous solution over 5 minutes. After confirming that the pH of the aqueous layer is around 9-10, add 107g (3.3mol) of paraformaldehyde (purity: 92%) in multiple additions over 30 minutes. At this point, monitor the temperature of the reaction system as it rises from 30°C to 55°C. Then, while stirring, air cool the system until the temperature drops to 30°C, and then stir at 30°C for 1 hour.

[0088] After stirring, 586 g of ethyl acetate and 210 g of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane were added to the flask. The temperature of the liquid in the flask was then raised to 55°C and reacted for 24 hours, followed by 3 hours at 60°C, 5 hours at 65°C, and 1 hour at 70°C, confirming the disappearance of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane. The temperature of the liquid in the flask was then cooled to 40°C. GPC analysis of the reaction solution showed that benzoxazine compounds accounted for 75% of the surface area, while the remaining 25% consisted of compounds with higher molecular weights than benzoxazine compounds (high molecular weight components).

[0089] After mixing 400g of pure water into the reaction end solution, stir for 30 minutes, let stand, and confirm separation from the organic layer before removing the water layer. Perform this water washing operation 6 times to confirm that the pH of the water layer is 7-8.

[0090] The solvent was then removed by distillation under reduced pressure at 40°C. After solvent removal, the mixture was cooled to obtain a non-flowing solid benzoxazine compound. The obtained benzoxazine compound was analyzed by GPC under the above analytical conditions, and the purity was 70% by area, with the content of high molecular weight components being 30% by area.

[0091] The resulting distillation residue was heated to 90°C and allowed to flow into a metal tray. After cooling to room temperature, it was pulverized to obtain 250 g of a yellow solid benzoxazine compound. The solvent content in the solid was 1.0% by weight. The yield was 78 mol relative to the 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane used.

[0092] The obtained solid was subjected to 1¹H-NMR analysis revealed peaks from the 3,3,5-trimethylcyclohexyl group near 0.4 and 0.8–1.0 ppm, peaks from the benzoxazine group near 3.3–4.0 ppm, peaks from allylamine near 4.8–5.2 ppm, and peaks from aromatic compounds near 6.6–7.3 ppm. 1 H-NMR spectra are shown in Figure 1 The results of this analysis clearly indicate that it is a benzoxazine compound represented by formula (1-4) as the target compound.

[0093] <Synthetic Example 2> (Synthesis of benzoxazine compounds represented by formulas (1-5)) [Chemistry 14]

[0094] To a 2L four-necked flask equipped with a thermometer, stirrer, cooling tube, and dropping funnel, add 120g (1.2mol) of allylamine hydrochloride. While stirring and monitoring the temperature rise, slowly add 101g (1.2mol) of 48% NaOH aqueous solution over 5 minutes. After confirming that the pH of the aqueous layer is around 9-10, add 96g (3.0mol) of paraformaldehyde (purity: 92%) in several batches over 1 hour. At this point, monitor the temperature of the reaction system rising from 30°C to 45°C. Then, while stirring, air cool the system until the temperature drops to 30°C, and then stir at 30°C for 1 hour.

[0095] After stirring, 584 g of ethyl acetate and 211 g of 1,1-bis(4-hydroxyphenyl)cyclododecane were added to the flask. The temperature of the liquid in the flask was then raised to 55°C, and the reaction was carried out for 32 hours. Since 1,1-bis(4-hydroxyphenyl)cyclododecane remained, the reaction was further carried out at 60°C for 4 hours, confirming the disappearance of 1,1-bis(4-hydroxyphenyl)cyclododecane. The temperature of the liquid in the flask was then cooled to 40°C. GPC analysis of the reaction solution showed that benzoxazine compounds accounted for 73% of the area, with the remaining 27% being compounds with higher molecular weights than benzoxazine compounds (high molecular weight components).

[0096] After mixing 400g of pure water into the reaction end solution, stir for 30 minutes, let stand, and confirm separation from the organic layer before removing the water layer. Perform this water washing operation 6 times to confirm that the pH of the water layer is 7-8.

[0097] The solvent was then removed by distillation under reduced pressure at 40°C. After solvent removal, the mixture was cooled to obtain a non-flowing solid benzoxazine compound. The obtained benzoxazine compound was analyzed by GPC under the above analytical conditions, and the purity was 70% by area, with the content of high molecular weight components being 30% by area.

[0098] The resulting distillation residue was heated to 90°C and allowed to flow into a metal tray. After cooling to room temperature, it was pulverized to obtain 308 g of a yellow solid benzoxazine compound. The solid contained 9.9% by weight of solvent. The yield was 90 mol% relative to the 1,1-bis(4-hydroxyphenyl)cyclododecane used.

[0099] The obtained solid was subjected to 1 ¹H-NMR analysis revealed peaks from cyclododecane around 0.4 and 0.8–1.0 ppm, peaks from benzoxazine around 3.3–4.0 ppm, peaks from allylamine around 4.8–5.2 ppm, and peaks from aromatic compounds around 6.6–7.3 ppm. 1 H-NMR spectra are shown in Figure 2 The results of this analysis clearly indicate that it is a benzoxazine compound represented by formula (1-5) as the target compound.

[0100] <Comparative Synthesis Example 1> (Synthesis of the benzoxazine compound represented by formula (i)) [Chemistry 15]

[0101] 19.5 g of water and 19.5 g of granular NaOH were added to a 500 mL four-necked flask equipped with a thermometer, stirrer, and cooling tube, and stirred. 19.5 g of allylamine hydrochloride was added to the alkaline solution, and the mixture was stirred for 1 hour under nitrogen atmosphere. Then, 39.1 g of paraformaldehyde (purity: 92%) was added in small batches, and the mixture was stirred for 5 hours. 93 g of ethyl acetate and 50 g of bisphenol F were added to the solution, and the mixture was stirred at 30–40 °C for 13 hours. During the process, due to increased viscosity, an additional 46 g of ethyl acetate was added. The disappearance of bisphenol F was confirmed by high-performance liquid chromatography (HPLC). GPC analysis of the reaction solution showed that the proportion of the benzoxazine compound represented by formula (i) present in the reaction solution was 65% by area, with the remaining 35% by area being high molecular weight components.

[0102] After the reaction was complete, the salt and unreacted paraformaldehyde were removed by filtration. The filtrate was then washed five times with 50 mL of water.

[0103] The washed filtrate was distilled at 40°C under reduced pressure to remove the solvent. The pressure was gradually reduced during distillation, eventually set to 1.4 kPa.

[0104] After distillation to remove the solvent, the mixture was cooled to obtain 55 g of the benzoxazine compound represented by formula (i) as a free-flowing oil. The solvent content in the oil was 1.0% by weight. The obtained oil was analyzed by GPC under the above analytical conditions, and the purity was 61% by area, with high molecular weight components accounting for 39% by area.

[0105] (Evaluation of preservation stability) Five g of the benzoxazine compounds represented by formulas (1-4), (1-5), and (i) obtained from Synthetic Examples 1, 2, and Comparative Synthetic Example 1 were placed in test tubes under atmospheric conditions and sealed. The test tubes containing the samples were then placed in a constant temperature bath and heated under the temperature and time conditions shown in Table 1 below. The purity before and after heating was determined by GPC, and the change was calculated. The results are summarized in Table 1.

[0106] [Table 1]

[0107] As shown in Table 1, compared with before heating, the purity of the benzoxazine compound represented by formula (i) obtained from Comparative Synthesis Example 1 decreased by 5.4% after being stored at room temperature (30°C) for 7 days and by 29.7% after being stored at a higher temperature of 50°C for 7 hours.

[0108] The results clearly show that the benzoxazine compound represented by formula (i) undergoes polymerization during storage, resulting in a decrease in purity. Therefore, there are issues with its operability as a resin raw material.

[0109] On the other hand, the purity of the compounds of formula (1-4) obtained from Synthesis Example 1 did not change at room temperature (30°C) and at a higher temperature of 50°C compared with before heating, thus it can be clearly determined that they can be stored for a long time.

[0110] Furthermore, compared with before heating, the purity of the compounds of formula (1-5) obtained from Synthesis Example 2 did not change under high temperature of 50°C, and the change was suppressed under room temperature (30°C), thus it can be clearly determined that they can be stored for a long time.

[0111] Compared with the benzoxazine compounds represented by the previously known formula (i), the benzoxazine resin composition of the present invention can be stored for a long time even at room temperature and has good storage stability. Furthermore, since it uses benzoxazine compounds with allyl groups, the storage or handling of raw materials in the manufacture of the benzoxazine resin composition is easier, which makes industrial production easier.

[0112] <Example 1> Using 15g of the compound of formula (1-4) obtained in Synthesis Example 1 as resin component (A), 16.5g of dicyclopentadiene-type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.: trade name "XD-1000") as resin component (B), 0.64g of triphenylphosphine (TPP) as component (D), and 40.0g of methyl ethyl ketone, the mixture was allowed to stand until completely dissolved. After complete dissolution, the solution was transferred to a tray and dried overnight in a ventilated environment, followed by drying in a vacuum dryer at 60°C for 4-5 hours. Then, the resulting composition was placed in a mold (φ100mm press-fit type) and cured using a hot press at 3MPa under conditions of 100°C / 1 hour and 130°C / 2 hours. Finally, post-curing was performed using a hot air circulating oven at 140°C / 2 hours, 150°C / 2 hours, 160°C / 2 hours, and 180°C / 2 hours to obtain the cured product.

[0113] <Comparative Example 1> The cured product was obtained in the same manner as in Example 1, except that 10.0 g of phenolic varnish-type curing agent (manufactured by AICA Industrial Co., Ltd.: trade name "BRG-555"), 24.0 g of dicyclopentadiene-type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.: trade name "XD-1000"), 0.64 g of triphenylphosphine and 40.0 g of methyl ethyl ketone were used.

[0114] The cured products obtained in Example 1 and Comparative Example 1 were evaluated for their glass transition temperature (Tg) and dielectric properties under the analytical conditions described above. The results are summarized in Table 2.

[0115] [Table 2]

[0116] The cured products of the benzoxazine resin compositions containing compounds of formulas (1-4) obtained in Example 1 were confirmed to have good heat resistance (Tg) and dielectric properties.

[0117] As can be clearly seen from the above, the benzoxazine resin composition of the present invention is very useful as a resin material for prepregs, copper-clad laminates, printed circuit boards, sealants for semiconductors or electronic components, electrical and electronic molded parts, automotive parts, laminates, coatings, and resist inks due to its excellent heat resistance and dielectric properties.

Claims

1. A benzoxazine resin composition, characterized in that, It contains resin component (A) and resin component (B). Resin component (A): benzoxazine compounds represented by general formula (1); Resin component (B): Epoxy resin with a cyclic aliphatic structure; [Chemistry 1] In the formula, R1 independently represents an alkylene group with 1 to 4 carbon atoms, and X represents a cycloalkane group with 5 to 20 carbon atoms.

2. The benzoxazine resin composition according to claim 1, characterized in that, In the general formula (1), X is selected from at least one of cyclohexylene, 3-methylcyclohexylene, 4-methylcyclohexylene, 3,3,5-trimethylcyclohexylene and cyclododecylene.

3. The benzoxazine resin composition according to claim 1, characterized in that, The proportion of the resin component (A) relative to the total amount of the resin components is in the range of 1% by weight to 99% by weight.

4. The benzoxazine resin composition according to claim 1, characterized in that, The resin component (B) is selected from at least one of the following: cycloalkylidene bisphenol type epoxy resin, dicyclopentadiene type epoxy resin, and alicyclic epoxy resin.

5. The benzoxazine resin composition according to claim 1, characterized in that, It further contains ingredient (D). Ingredient (D): Curing accelerator.

6. A cured product, characterized in that, It is the cured product of the benzoxazine resin composition according to claim 1.

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