Phosphorus-containing phenolic compound, curable resin composition containing said phosphorus-containing phenolic compound, cured product, and method for producing said phosphorus-containing phenolic compound

Abstract

Provided is a phosphorus-containing phenol compound which has excellent flame retardancy, heat resistance, and dielectric properties in a cured product thereof, and which has a low water absorption rate and a small change in dielectric properties after water absorption. The present invention provides a phosphorus-containing phenol compound represented by general formula (1). In general formula (1), Ar is an optionally substituted C6-30 aromatic ring group, each R1 is independently hydrogen or a substituent represented by general formula (2), and at least one R1 includes the substituent represented by general formula (2). And m is an integer of 3-6. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a reactive phosphorus compound, in particular to a phosphorus-containing phenol compound, which is useful as a flame retardant for thermosetting resins such as epoxy resins. In addition, the present invention also relates to a curable resin composition comprising the phosphorus-containing phenol compound and a curable resin, and a method for producing the phosphorus-containing phenol compound. Background Art

[0002] Plastic materials are used in a wide range of applications such as building materials and electrical and electronic equipment due to their excellent mechanical properties and molding processability. However, since most plastic materials are easily flammable, they must be flame-retardant for safety against heat ignition and fire in applications such as electrical and electronic products, OA equipment, and communication equipment.

[0003] Flame retardant technology for plastic materials is not limited to the type of resin and the purpose. Generally, additive flame retardants such as halogen flame retardants, inorganic flame retardants, and phosphorus flame retardants are added. However, among these, halogen flame retardants, mainly bromine-based ones, are pointed out to be highly carcinogenic. The sources of oxalic acid are being developed in the direction of limiting its use in response to the current trend of reducing environmental load substances. In addition, although inorganic flame retardants such as magnesium hydroxide and aluminum hydroxide have a flame retardant effect due to heat absorption, they need to be added in large quantities to achieve sufficient flame retardancy, which causes various properties of plastic molded products to decrease. Therefore, phosphorus flame retardants that do not produce harmful substances and can achieve flame retardancy with a small amount of addition are used in large quantities, but even so, the effects on properties such as reduced processability and reduced glass transition temperature due to exudation cannot be avoided.

[0004] In order to solve the problems of these additive flame retardants, a reactive flame retardant containing phosphorus atoms as a flame retardant component and having a reactive group has been developed and widely used. As a reactive flame retardant that can be applied to epoxy resin compositions frequently used in the electronic and electrical fields, for example, Patent Document 1 discloses a phosphorus-containing epoxy resin obtained by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (hereinafter referred to as "DOPO") with quinones and then reacting with epoxy resin. Patent Document 2 discloses a phenolic resin as a curing agent for epoxy resin, the phenolic resin being obtained by reacting bisphenol A with formaldehyde to obtain hydroxymethyl bisphenol A and then reacting with DOPO, and Patent Document 3 discloses a phenolic resin obtained by reacting DOPO with anisaldehyde and then reacting with a phenolic resin containing a triazine skeleton to introduce phosphorus atoms. These resins solve the problem of processability such as the bleeding of flame retardants, and no deterioration of thermal properties such as heat resistance is observed.

[0005] However, in recent years, in the field of electronic and electrical materials where flame retardancy is an essential characteristic, the characteristics required of flame retardants have also changed to a higher degree due to the rapid evolution of electronic devices represented by smartphones. In particular, in the field of information and communication, as the amount of information processing increases, the frequency of signals is increased. In order to reduce transmission losses, flame retardant materials are also strongly required to have low dielectric constants and low dielectric loss tangents. Furthermore, requirements such as low moisture absorption, stability of its characteristics relative to environmental changes, and heat resistance are gradually becoming more diverse. As a flame retardant that can be applied to epoxy resin compositions showing low dielectric properties, a phosphorus-containing active ester introduced with a DOPO skeleton is disclosed in Patent Document 4 to exhibit flame retardancy and low dielectric. In this way, epoxy resins and phosphorus-containing curing agents that can impart flame retardancy without reducing general properties such as heat resistance by introducing DOPO into the structure are widely known, but the DOPO skeleton has the following problems: it is easy to hydrolyze, and the hydroxyl groups generated by hydrolysis cause a large change in the dielectric properties after moisture absorption and water absorption. To address this problem, Patent Document 5 discloses a phosphate ester type phenol compound that has little change in dielectric properties after absorbing water. However, the dielectric properties and heat resistance are insufficient, and there is no flame retardant that fully meets the high demands.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent No. 3533973

[0009] Patent Document 2: Japanese Patent No. 5678109

[0010] Patent Document 3: Japanese Patent No. 5516980

[0011] Patent Document 4: Japanese Patent No. 5637418

[0012] Patent document 5: WO2021 / 256351 Summary of the invention

[0013] Therefore, the problem to be solved by the present invention is to provide a phosphorus-containing phenol compound whose cured product has excellent flame retardancy, heat resistance, and dielectric properties, low water absorption, and small change in dielectric properties after water absorption, as well as a curable resin composition comprising the above-mentioned phosphorus-containing phenol compound and a curable resin, an epoxy resin composition using the above-mentioned phosphorus-containing phenol compound as a curing agent, its cured product, and a method for producing the above-mentioned phosphorus-containing phenol compound.

[0014] The present inventors have conducted intensive studies on the above-mentioned problems and have found that a phosphorus-containing phenol compound having a specific structure has excellent heat resistance and dielectric properties and has little change in dielectric properties after absorbing water, thereby completing the present invention.

[0015] That is, the present invention is a phosphorus-containing phenol compound represented by the following formula (1).

[0016]

[0017] In the general formula (1), Ar is an aromatic ring group having 6 to 30 carbon atoms which may have a substituent, and R 1 Each independently represents hydrogen or a substituent represented by the following general formula (2), at least one R 1 The substituent represented by the general formula (2) is included. m is an integer of 3-6.

[0018]

[0019] In the general formula (2), R 2 and R 3 Each of n2 and n3 is independently a linear or branched alkyl group having 1 to 5 carbon atoms, and each of n2 and n3 is independently an integer of 0 to 5.

[0020] In the present invention, a phosphorus-containing phenol compound in which Ar is an aromatic ring group selected from a benzene skeleton, a naphthalene skeleton, a biphenyl skeleton, and an anthracene skeleton is preferred, and a phosphorus-containing phenol compound in which Ar is a benzene skeleton is more preferred.

[0021] In the present invention, the phosphorus-containing phenol compound wherein m is 3 is more preferred. Particularly preferred is a phenol compound wherein m is 3 and contains 10 to 80 mol % of three OR 1 Two Rs in the base 1 is hydrogen and one R 1 A compound (1-substituted product) having a substituent represented by the general formula (2), 5 to 50 mol% of three OR 1 One R in the base 1 is hydrogen and two R 1 A compound (disubstituted product) having a substituent represented by the general formula (2), 1 to 50 mol% of three OR 1 The Three Rs of Basics 1 A phosphorus-containing phenol compound which is a compound (tri-substituted product) having a substituent represented by the general formula (2).

[0022] The present invention is a method for producing a phosphorus-containing phenol compound, characterized in that 0.1 to 0.9 mol of a compound represented by the general formula (4) is reacted with 1 mol of hydroxyl groups of the compound represented by the general formula (3).

[0023]

[0024] In the general formula (3), Ar and m have the same meanings as in the general formula (1).

[0025]

[0026] In the general formula (4), X represents a halogen atom, R 2 , R 3 , n2, n3 have the same meanings as in the general formula (2).

[0027] The present invention is a curable resin composition comprising the phosphorus-containing phenol compound and a curable resin. The present invention is a cured product obtained by curing the curable resin composition.

[0028] The phosphorus-containing phenol compound of the present invention has little change in dielectric properties after absorbing water, and is very useful as a flame retardant material for reducing transmission loss due to the increase in the frequency of information processing in electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a GPC chart of the phosphorus-containing phenol compound obtained in Example 2. (The dotted line is the raw material, and the solid line is the product) DETAILED DESCRIPTION

[0030] Hereinafter, the present invention will be described in detail.

[0031] The phosphorus-containing phenol compound of the present invention is represented by the following general formula (1).

[0032]

[0033] In the general formula (1), Ar is an aromatic ring group having 6 to 30 carbon atoms which may have a substituent. The aromatic ring group is not particularly limited, and examples thereof include benzene, furan, pyrrole, thiophene, imidazole, pyrazole, Azoles, Isopropylamine An aromatic ring group obtained by removing m hydrogen atoms from a monocyclic aromatic compound such as oxazole, thiazole, isothiazole, pyridine, pyrimidine, pyridazine, pyrazine, triazine, etc.; an aromatic ring group obtained by removing m hydrogen atoms from a condensed aromatic compound such as naphthalene, anthracene, phenanthren, quinoline, isoquinoline, quinazoline, phthalazine, pteridine, coumarin, indole, benzimidazole, benzofuran, acridine, etc. In addition, it can also be an aromatic ring group obtained by combining a plurality of these aromatic compounds, for example, an aromatic ring group obtained by removing m hydrogen atoms from a ring-aggregated aromatic compound such as biphenyl, binaphthyl, bipyridine, bithiophene, phenylpyridine, phenylthiophene, terphenyl, diphenylthiophene, quaterphenyl, etc. Preferred are benzene, naphthalene, biphenyl and anthracene. More preferably, benzene.

[0034] The aromatic ring represented by Ar may contain -OR 1 As the substituent, there can be mentioned an alkyl group having 1 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms, and preferably an alkyl group having 1 to 10 carbon atoms.

[0035] The alkyl group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, 1,2-dimethylpropyl, n-hexyl, isohexyl, n-nonyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and cyclononyl. Preferred groups include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl. More preferred groups include methyl and ethyl.

[0036] The alkoxy group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, 2-ethylhexyloxy, octyloxy, nonyloxy, etc. These substituents may be used alone or in combination of two or more.

[0037] In the general formula (1), m is an integer of 3 to 6, preferably 3 or 4, and more preferably 3. 1 Each independently represents hydrogen or a substituent represented by the following general formula (2).

[0038]

[0039] In the general formula (2), R 2 and R 3 Each is independently a linear or branched alkyl group having 1 to 5 carbon atoms.

[0040] Specific examples of the alkyl group having 1 to 5 carbon atoms include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, etc. Among these, methyl, ethyl, propyl, isopropyl are preferred from the viewpoint of reactivity in production and availability, and methyl is particularly preferred.

[0041] n2 and n3 are each independently an integer of 0 to 5, preferably an integer of 0 or 2 or more, and more preferably 2. When n2 and n3 are 1 or more, R 2 , R 3 The substitution position on the benzene ring is not particularly limited, and preferably exists in the ortho position or the meta position independently of the phosphate bond. By having an alkyl group at the ortho position, the phosphate is blocked hydrophobically, the water absorption rate is reduced, and hydrolysis is inhibited, so the characteristics of the phosphorus-containing phenol compound of the present invention can be further improved. Therefore, it is particularly preferred to have an alkyl group substituted at two ortho positions relative to the phosphate bond, and preferably n2 and n3 are 2 or more.

[0042] The phosphorus-containing phenol compound of the present invention has R 1 The ratio of hydrogen to the substituent represented by the general formula (2) is not particularly limited, but at least one R 1The phosphorus-containing phenol compound of the present invention can exhibit excellent flame retardancy by including the structure of the general formula (2). The phosphorus-containing phenol compound (mixture) of the present invention is a compound (mixture) JISUAN, in which R 1 In the above, the ratio of the substituent represented by the general formula (2) is preferably 10 mol% or more, more preferably 30 mol% or more, and even more preferably 50 mol% or more.

[0043] Examples of the phosphorus-containing phenol compound of the present invention include compounds having the following structures and mixtures thereof, but are not limited thereto.

[0044]

[0045] The phosphorus-containing phenol compound of the present invention does not need to be used as a single compound, and may also be a mixture of compounds containing different numbers of substituents represented by a plurality of general formula (2). The more the number of substituents represented by general formula (2) increases, the better the flame retardancy and dielectric properties are, the less the structure of general formula (2) decreases, the more the hydroxyl group as a reactive group increases, and thus the heat resistance is improved, and the leakage of the flame retardant can be prevented. Therefore, by containing a plurality of compounds containing different numbers of substituents represented by general formula (2), a well-balanced property can be formed.

[0046] The production method is described in detail below. The phosphorus-containing phenol compound of the present invention can be obtained by reacting a polyphenol compound represented by the general formula (3) described later with a phosphorus compound represented by the general formula (4). Since the polyphenol compound of the raw material does not contain phosphorus, the introduction of the substituent represented by the general formula (2) can be determined by measuring the phosphorus content of the compound after the reaction.

[0047] The introduction of the substituent represented by the general formula (2) can be judged by the phosphorus content. If the phosphorus content is not 0, the introduction of the substituent represented by the general formula (2) can be judged, but if the phosphorus content is low, flame retardancy is not exhibited. From the perspective of flame retardancy, the higher the phosphorus content, the more preferred. However, the higher the phosphorus content, the less hydroxyl groups there are, and sometimes the heat resistance is insufficient or bleeding occurs. Therefore, the phosphorus content of the phosphorus-containing phenolic compound is preferably 1.5 to 15.0% by mass, more preferably 3.0 to 12.0% by mass, and further preferably 5.0 to 10.0% by mass.

[0048] The hydroxyl group equivalent of the phosphorus-containing phenol compound is in the range of 50 to 1000 g / eq, preferably 80 to 800 g / eq, and more preferably 100 to 600 g / eq.

[0049] From the viewpoint of raw material availability, the phosphorus-containing phenol compound of the present invention preferably has Ar of benzene and m of 3. In this case, it is preferably a mixture of the following general formulas (5), (6), and (7). It is more preferably a mixture containing 10 to 80 mol% of two R 1 is hydrogen and one R 1 A compound (substituted product) having a substituent represented by the general formula (2), 5 to 50 mol% of one R represented by the following general formula (6) 1 is hydrogen and two R 1 A compound (disubstituted product) having a substituent represented by the general formula (2), 1 to 50 mol% of three R represented by the following general formula (7) 1 The compound (tri-substituted product) having a substituent represented by the general formula (2) can obtain a cured product having excellent balance among flame retardancy, heat resistance and dielectric properties. More preferably, the 1-substituted product is 20 to 70 mol%, the 2-substituted product is 10 to 40 mol%, and the 3-substituted product is 2 to 40 mol%. It should be noted that although unreacted raw material phenols may remain, it is preferably less than 30 mol%.

[0050]

[0051]

[0052] In the above general formulas (5), (6) and (7), R 2 , R 3 , n2, n3 have the same meanings as in the general formula (2).

[0053] The compositions of the above general formulae (5), (6) and (7) can be confirmed by liquid chromatography, size exclusion chromatography and the like.

[0054] Next, the method for producing the phosphorus-containing phenol compound of the present invention is described. The phosphorus-containing phenol compound of the present invention is an aromatic phosphate having one or more phenolic hydroxyl groups, and the production method is in accordance with a general method for producing aromatic phosphates. That is, as an example of a reaction form, an esterification reaction using phosphorus oxyhalide (phosphorus oxyhalide) and phenols as raw materials can be performed, and the corresponding phosphate can be obtained by dehydrohalogenation reaction.

[0055] In the esterification reaction, in order to prevent the hydrolysis reaction using the by-produced hydrogen halide as a catalyst and to efficiently obtain the product, operations such as using a catalyst or removing the desorbed hydrogen halide from the reaction system may be performed.

[0056] The hydrogen halide (e.g., hydrogen chloride) that is released is a gas, and since its volume increases when it is gasified, it is easy to be released outside the reaction system for a raw material with good reactivity, but in the case of a raw material with low reactivity, the amount of hydrogen halide released is small, and it is easy to stay in the system, thereby sometimes causing a hydrolysis reaction. In such a case, it is effective to capture the generated hydrogen halide without causing a hydrolysis reaction, and amines are sometimes used as hydrogen halide capture agents.

[0057] The phosphorus-containing phenol compound of the present invention is a compound represented by the above-mentioned general formula (1), and therefore it is required to react the polyhydroxy compound represented by the following general formula (3) corresponding to the general formula (1) as a raw material with the raw materials of the phosphorus halide compound represented by the following general formula (4) corresponding to the above-mentioned general formula (2), namely, phenols and oxyhalogenated phosphorus.

[0058]

[0059] In the general formula (3), Ar and m have the same meanings as in the general formula (1).

[0060] However, if a polyhydroxy compound represented by the general formula (3) having multiple hydroxyl groups, which is an essential raw material for the phosphorus-containing phenol compound of the present invention, is reacted with a phosphorus oxyhalide, a side reaction of the multiple hydroxyl groups reacting with the phosphorus oxyhalide occurs. Therefore, it is necessary to appropriately adjust the reaction order, the feed ratio of the raw materials, the reaction conditions, etc. in order to effectively obtain the target compound.

[0061] Therefore, instead of reacting the three raw materials of the polyhydric hydroxy compound represented by the general formula (3) and the phosphorus halide compound represented by the general formula (4), namely, phenols and phosphorus oxyhalide, at once, phosphorus oxyhalide, such as phosphorus oxychloride (POCl3), is first reacted with phenols to obtain a phosphorus halide compound represented by the following general formula (4), and then the phosphorus halide compound represented by the general formula (4) is reacted with the polyhydric hydroxy compound represented by the general formula (3), thereby effectively obtaining the target compound. In this case, in the front-stage reaction, phenols are added in a ratio of 2 moles to 1 mole of phosphorus oxyhalide. Preferably, the phenols are in the range of 1.8 to 2.2 moles, and more preferably in the range of 1.9 to 2.1 moles.

[0062]

[0063] In the compound represented by the general formula (4), R 2 , R 3 , n2, n3 have the same meanings as in the general formula (2). X represents a halogen atom.

[0064] The phosphorus-containing phenol compound of the present invention can be obtained by reacting the hydroxyl group of the polyhydroxy compound represented by the general formula (3) with the phosphorus halide compound represented by the general formula (4). Therefore, by adjusting the molar ratio of the phosphorus halide compound of the general formula (4) to the hydroxyl group, the hydroxyl equivalent and the phosphorus content can be controlled.

[0065] Regarding the molar ratio of the reaction, the phosphorus halide compound represented by the general formula (4) is preferably 0.1 to 0.9 moles, more preferably 0.2 to 0.8 moles, and even more preferably 0.3 to 0.7 moles, relative to 1 mole of the hydroxyl group of the polyvalent hydroxyl compound represented by the general formula (3). If it is less than 0.1 mole, the phosphorus content decreases and the flame retardancy is insufficient, which is not preferred. If it is more than 0.9 mole, the hydroxyl group as a reactive group decreases and the heat resistance is insufficient, which is not preferred.

[0066] The curable flame retardant resin composition of the present invention contains the above-mentioned phosphorus-containing phenol compound as an essential component, and can be obtained by mixing the phosphorus-containing phenol compound in a curable resin. As the curable resin, there is no limitation as long as it contains a curable resin that reacts with the hydroxyl group of the phosphorus-containing phenol compound of the present invention, and examples thereof include epoxy resins or maleimide resins.

[0067] The epoxy resin that can be used in the curable resin composition is not particularly limited, and examples thereof include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, phenol novolac type epoxy resin, naphthol novolac type epoxy resin, dicyclopentadiene type epoxy resin, phenol aralkyl type epoxy resin, naphthol type epoxy resin, naphthol aralkyl type epoxy resin, naphthalene type epoxy resin, glycidylamine type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexanedimethanol type epoxy resin, trimethylol type epoxy resin, halogenated epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, etc. These epoxy resins can be used alone or in combination of two or more.

[0068] The amount of the above-mentioned phosphorus-containing phenol compound and epoxy resin is determined based on the phosphorus content of the resin composition. The phosphorus content in the resin composition is preferably 0.5 to 5.0% by mass, and more preferably 1.0 to 4.0% by mass. When it is below 0.5% by mass, no flame retardancy is found. When it is above 5.0% by mass, the amount of the phosphorus-containing phenol compound is large, the hydroxyl group becomes too much relative to the epoxy group, the crosslinking is insufficient, and the cured product becomes brittle, so it is not preferred. In addition, when the epoxy resin is used for the curable resin, a curing agent other than the phosphorus-containing phenol compound of the present invention may be included.

[0069] Examples of curing agents that can be used together with the phosphorus-containing phenol compound include phenolic curing agents, amine compounds, amide compounds, acid anhydride compounds, naphthol curing agents, active ester curing agents, benzoxazine curing agents, cyanate curing agents, acid anhydride curing agents, etc. These can be used alone or in combination of two or more.

[0070] As the amount of curing agent other than the phosphorus-containing phenol compound of the present invention, the phosphorus content of the resin composition of the present invention is preferably 0.5 to 5.0% by mass, and the molar ratio (Nh / Ne) of the total number of moles (Nh) of the reaction points of the epoxy groups of the phosphorus-containing phenol compound and other curing agents to the number of moles (Ne) of the epoxy groups is 0.7 to 1.3, preferably 0.9 to 1.1. When the molar ratio is outside the range, crosslinking is insufficient and a brittle cured product is obtained, which is not preferred.

[0071] The resin composition of the present invention may further include a curable resin other than epoxy resin. Examples of the curable resin other than epoxy resin include free radical polymerizable resins such as vinyl ester resins, polyvinyl benzyl resins, unsaturated polyester resins, curable vinyl resins, maleimide resins, and cyanate resins.

[0072] The curable resin composition of the present invention may contain a curing accelerator as required. The curing accelerator used here includes, for example, phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, amine complex salts, etc. The amount of the curing accelerator added is preferably 0.1 to 10.0 parts by mass relative to 100 parts by mass of the total of the phosphorus-containing phenolic compound, the curable resin, and other curing agents.

[0073] The resin composition of the present invention may contain, in addition to the above-mentioned components, other components such as thermosetting resins, thermoplastic resins, organic fillers, inorganic fillers, organic solvents, thickeners, defoamers, adhesion-imparting agents, colorants, additives, etc. as appropriate.

[0074] Examples of thermoplastic resins include polystyrene, polyphenylene ether resins, polyetherimide resins, polyethersulfone resins, PPS resins, polycyclopentadiene resins, polycycloolefin resins, and the like; known thermoplastic elastomers, such as styrene-ethylene-propylene copolymers, styrene-ethylene-butylene copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, hydrogenated styrene-butadiene copolymers, hydrogenated styrene-isoprene copolymers, and the like; or rubbers, such as polybutadiene and polyisoprene. Preferred examples include polyphenylene ether resins (unmodified) and hydrogenated styrene-butadiene copolymers.

[0075] Fillers can be added to the curable resin composition of the present invention. As fillers, fillers added to the cured product of the curable resin composition in order to improve heat resistance and flame retardancy can be cited, and known fillers can be used without particular limitation. In addition, by containing fillers, heat resistance, dimensional stability, flame retardancy, etc. can be further improved. Specifically, silicon dioxide such as spherical silica; metal oxides such as aluminum oxide, titanium oxide and mica; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; talc, aluminum borate, barium sulfate and calcium carbonate, etc. can be cited. When using metal hydroxides such as aluminum hydroxide and magnesium hydroxide, they act as flame retardant aids, and flame retardancy can be ensured even if the phosphorus content is low. Among them, silicon dioxide, mica and talc are preferred, and spherical silica is more preferred. In addition, these can be used alone or in combination of two or more.

[0076] The filler can be used directly, but fillers obtained by surface-treating a silane coupling agent such as a vinyl silane type, a methacryloxy silane type, an acryloxy silane type, and a styryl silane type, an epoxy silane type, an amino silane type, or a cationic silane type can also be used. This improves the bonding strength with the metal foil and the interlayer bonding strength between the resins. In addition, the above-mentioned silane coupling agent can be added and used by the overall blending method instead of using a method of pre-surface-treating the filler.

[0077] The content of the filler is preferably 10 to 200 parts by mass, more preferably 30 to 150 parts by mass, based on 100 parts by mass of the total solid content excluding the filler (including organic components such as monomers and flame retardants, excluding solvents).

[0078] The curable resin composition of the present invention may further contain additives other than those mentioned above. Examples of the additives include defoamers such as silicone defoamers and acrylate defoamers, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes, pigments, lubricants, dispersants such as wetting dispersants, and the like.

[0079] The cured product obtained by curing the curable resin composition of the present invention can be used in the form of a molded product, a laminate, a casting, an adhesive, a coating, or a film. For example, the cured product of the semiconductor packaging material is a casting or a molded product. As a method for obtaining the cured product for the above-mentioned purpose, the cured product can be obtained by casting the curable resin composition, or molding using a transfer molding machine, an injection molding machine, etc., and further heating at 80 to 230° C. for 0.5 to 10 hours.

[0080] The curable resin composition of the present invention can also be used in the form of a prepreg. When manufacturing a prepreg, it can be prepared in a varnish state for the purpose of impregnating a substrate (fibrous substrate) for forming a prepreg or for the purpose of making a circuit substrate material for forming a circuit substrate, thereby preparing a resin varnish.

[0081] The resin varnish is suitable for use in circuit boards and can be used as a varnish for circuit board materials. Specifically, the circuit board materials mentioned here include printed wiring boards, printed circuit boards, flexible printed wiring boards, build-up wiring boards, and the like.

[0082] The above-mentioned resin varnish can be prepared, for example, as follows.

[0083] First, the components of the present invention such as the phosphorus-containing phenolic compound and epoxy resin component that can be dissolved in an organic solvent are put into an organic solvent to dissolve it. At this time, heating can be performed as needed. Then, as needed, components insoluble in organic solvents such as inorganic fillers are added, and a ball mill, a bead mill, a planetary mixer, a roller mill, etc. are used to disperse them, thereby preparing a varnish-like curable resin composition. As the organic solvent used here, there is no particular limitation as long as it is an organic solvent that dissolves the resin component used in the epoxy resin composition of the present invention and does not hinder the curing reaction. For example, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as ethyl acetate, propyl acetate, and butyl acetate; polar solvents such as dimethylacetamide and dimethylformamide; aromatic hydrocarbon solvents such as toluene and xylene, etc., these can be used alone, or mixed with two or more.

[0084] When preparing the resin varnish, the amount of the organic solvent used is preferably 5 to 900 mass %, more preferably 10 to 700 mass %, and particularly preferably 20 to 500 mass %, based on 100 mass % of the curable resin composition of the present invention.

[0085] As the base material for making prepreg, known materials can be used, for example, base materials such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper can be used separately, or two or more can be used in combination. For these base materials, coupling agents can be used as required for the purpose of improving the adhesiveness of the interface between resin and base material. As coupling agent, general coupling agents such as silane coupling agent, titanate coupling agent, aluminum coupling agent, zirconium aluminate coupling agent can be used.

[0086] As a method for obtaining the prepreg of the present invention, there can be cited a method in which the above-mentioned resin varnish is impregnated into a substrate and then dried. The impregnation is performed by dipping, coating, etc. The impregnation can also be repeated multiple times as needed. In addition, at this time, multiple solutions with different compositions or concentrations can be used for repeated impregnation to adjust the final desired resin composition and resin amount. After impregnation, the prepreg can be obtained by heating and drying at 100 to 180° C. for 1 to 30 minutes. Here, the amount of resin in the prepreg is preferably 30 to 80% by mass of the resin component.

[0087] The curable resin composition of the present invention can also be used in the form of a laminate. When a prepreg is used to form a laminate, one or more prepregs are stacked, and a metal foil is arranged on one side or both sides to form a laminate, and the laminate is heated and pressurized to be laminated and integrated. Here, as the metal foil, copper, aluminum, brass, nickel, etc. can be used alone, or their alloys and composite metal foils can be used. As the conditions for heating and pressurizing the laminate, it is sufficient to adjust the heating and pressurization appropriately under the conditions for curing the curable resin composition. However, if the pressure of the pressurization is too low, sometimes bubbles remain inside the obtained laminate and the electrical properties are reduced. Therefore, it is preferred to pressurize under conditions that satisfy the formability. For example, the temperature can be set to 180-230°C, and the pressure can be set to 49.0-490.3N / cm 2 (5~50kgf / cm 2 ), and the heating and pressing time is set to 40 to 240 minutes. Furthermore, the single-layer laminate obtained in this way can be used as an inner layer material to make a multilayer board. In this case, the laminate is first subjected to circuit formation by an additive method or a subtractive method, and the surface of the formed circuit is treated with an acid solution to perform a blackening treatment to obtain an inner layer material. An insulating layer is formed on the circuit forming surface on one side or both sides of the inner layer material by a resin sheet, a metal foil with a resin, or a prepreg, and a conductor layer is formed on the surface of the insulating layer to form a multilayer board.

[0088] The method of producing a build-up film from the curable composition of the present invention includes, for example, coating the resin varnish on a support film and drying it to form a film-like insulating layer. The film-like insulating layer thus formed can be used as a build-up film for a multilayer printed wiring board.

[0089] The drying step is preferably performed in such a manner that the content of the organic solvent in the layer of the build-up film resin composition is 10% by mass or less, preferably 5% by mass or less. The drying conditions also vary depending on the type and amount of the organic solvent in the varnish, and the drying can be performed at 50 to 160° C. for about 3 to 20 minutes.

[0090] The thickness of the build-up layer formed on the support is usually greater than the thickness of the conductor layer. The thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, so the thickness of the resin composition layer is preferably 10 to 100 μm.

[0091] In addition, from the viewpoint of being able to prevent the adhesion of dirt and the like to the surface or preventing damage, the build-up film of the present invention is preferably protected by a protective film.

[0092] Examples of the support film and the protective film include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; polyesters such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate, polyimide, and release paper, copper foil, aluminum foil, and other metal foils. In addition to the matte treatment and corona treatment, the support film and the protective film may also be subjected to a release treatment.

[0093] The thickness of the support film is not particularly limited, but is usually 10 to 150 μm, preferably 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0094] The support film is peeled off after being laminated on the circuit board or after being cured by heat to form an insulating layer. If the support film is peeled off after the adhesive film is cured by heat, it is possible to prevent the curing hindrance caused by oxygen in the curing process, and further prevent the attachment of garbage, etc. In the case of peeling off after curing, the support film is usually subjected to a demolding treatment in advance.

[0095] Example

[0096] Next, the present invention will be described by way of examples, but the present invention is not limited thereto. "Parts" in each example are parts by mass.

[0097] In addition, the physical property measurement of each cured product sample in the example was performed by the method shown below.

[0098] (1) Molecular weight and molecular weight distribution of polymers: The molecular weight and molecular weight distribution of phosphorus-containing phenol compounds were measured using GPC (HLC-8120GPC manufactured by Tosoh Corporation) with tetrahydrofuran as solvent, a flow rate of 1.0 ml / min, a column temperature of 38° C., and a calibration curve based on monodisperse polystyrene.

[0099] (2) Hydroxyl equivalent: Accurately weigh about 6 mg / eq of a sample in a 100 mL stoppered flask, add 3 mL of a reagent mixed with acetic anhydride / pyridine = 3 / 1 (volume ratio), install a condenser, heat and reflux for 5 minutes on a hot plate, let cool for 5 minutes, and then add 1 mL of water. The liquid is titrated potentiometrically with a 0.5 mol / L KOH / MeOH solution to calculate the equivalent.

[0100] (3) Phosphorus content: Sulfuric acid, hydrochloric acid and perchloric acid are added to the sample and heated for wet ashing so that all phosphorus atoms are orthophosphoric acid. Metavanadate and molybdate are reacted in a sulfuric acid acid solution, and the absorbance of the generated phosphovanadomolybdic acid complex at 420 nm is measured. The phosphorus atom content obtained is expressed in mass % using a calibration curve prepared in advance using potassium dihydrogen phosphate.

[0101] (4) Glass transition temperature: The glass transition temperature was determined from the baseline shift at a heating rate of 10° C. / min using a differential scanning calorimeter manufactured by Hitachi High-Tech Science Co., Ltd.

[0102] (5) Relative dielectric constant and dielectric loss tangent: According to IPC-TM-6502.5.5.9, the dielectric constant (Dk) and dielectric loss tangent (Df) at a frequency of 1 GHz were determined by a volumetric method using a material analyzer (manufactured by AGILENT Technologies) at 25°C and 60% humidity.

[0103] (6) Flame retardancy: Evaluation was performed using five test pieces by a vertical method in accordance with UL94. The evaluation was described as V-0, V-1, or V-2.

[0104] (7) Water absorption: According to JIS K 7209, a cured product sample was immersed in water at 23° C., and the saturated water content was determined.

[0105] (8) Dielectric property change rate after water absorption: The change rate was calculated from the following formula using the measured value (A1) of the cured sample before the water absorption test and the measured value (A2) after the water absorption test.

[0106] Dielectric property change rate (%) = (A2-A1) / A1×100

[0107] The following compounds were used as raw materials in the synthesis examples.

[0108] Phosphorus oxychloride (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0109] 2,6-Dimethylphenol (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0110] Phloroglucinol (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0111] (Synthesis Example 1) Synthesis of bis (2,6-diphenylyl) chlorophosphate (DXPC)

[0112] A 2L four-necked flask equipped with a stirrer, a thermometer, and a hydrochloric acid recovery device (a condenser connected to a water scrubber) was charged with 767 g (5 mol) of phosphorus oxychloride (the following structural formula),

[0113] POCl3

[0114] 2,6-Dimethylphenol (structural formula below) 1200g (9.8mol),

[0115]

[0116] 140 g of xylene as a solvent and 6.2 g (0.065 mol) of magnesium chloride as a catalyst were used. The obtained mixed solution was stirred and slowly heated to 160°C for about 3 hours to react, and the generated hydrogen chloride gas was recovered by a water scrubber. Then, the pressure in the flask was slowly reduced to 20 kPa at the same temperature to remove xylene, unreacted phosphorus oxychloride and 2,6-dimethylphenol, and by-produced hydrogen chloride, and 1700 g of a reaction product containing di-2,6-xylyl chlorophosphate (DXPC: the following structural formula) as the main component was obtained. In addition, the chlorine content of the reaction mixture was 10.9% by mass.

[0117]

[0118] (Example 1) Synthesis of phosphorus-containing phenol (compound A)

[0119] Into a 200 mL four-necked flask equipped with a stirrer, a thermometer, and a hydrochloric acid recovery device (a condenser connected to a water scrubber) were charged 51.6 g of mesitylene, 12.6 g (0.1 mol) of phloroglucinol (the following structural formula),

[0120]

[0121] 21.8 g (0.06 mol) of di-2,6-xylyl chlorophosphate obtained in Synthesis Example 1 and 0.4 g (0.004 mol) of anhydrous magnesium chloride as a catalyst were added. The obtained mixed solution was slowly heated to 155°C while stirring. After reaching 155°C, it was reacted for 18 hours and the generated hydrogen chloride was collected. After cooling to 60°C, 35 g of ethyl acetate was added, acid washing, neutralization, and water washing were performed twice, and the solvent was removed to obtain 26.1 g of compound A.

[0122] The hydroxyl equivalent of compound A was 125 g / eq, and the phosphorus content was 6.4% by mass. Furthermore, GPC confirmed that the compound A contained 68 mol% of a compound (1-substituted product, the following structural formula) formed by the reaction of one hydroxyl group of phloroglucinol with di-2,6-xylyl chlorophosphate, 10 mol% of a compound (2-substituted product, the following structural formula) formed by the reaction of two hydroxyl groups, 2 mol% of a compound (3-substituted product, the following structural formula) formed by the reaction of three hydroxyl groups, and 20 mol% of phloroglucinol.

[0123]

[0124]

[0125] (Example 2) Synthesis of phosphorus-containing phenol (compound B)

[0126] A 200 mL 4-necked flask equipped with a stirrer, a thermometer, and a hydrochloric acid recovery device (a condenser connected to a water scrubber) was filled with 110.9 g of mesitylene, 12.6 g (0.1 mol) of phloroglucinol, 54.5 g (0.15 mol) of di-2,6-xylyl chlorophosphate, and 0.8 g (0.008 mol) of anhydrous magnesium chloride as a catalyst. The obtained mixed solution was slowly heated to 155°C while stirring. After reaching 155°C, it was reacted for 18 hours and the generated hydrogen chloride was collected. After cooling to 60°C, 60 g of ethyl acetate was added, acid washing, neutralization, and water washing were performed twice, and the solvent was removed to obtain 51.2 g of compound B.

[0127] The hydroxyl equivalent of compound B was 412 g / eq, and the phosphorus content was 8.4% by mass. Furthermore, GPC confirmed that the compound (1-substituted product) was 39.5 mol% formed by the reaction of one hydroxyl group of phloroglucinol with bis-2,6-xylyl chlorophosphate, 34.0 mol% formed by the reaction of two hydroxyl groups with phloroglucinol (2-substituted product), 25.0 mol% formed by the reaction of three hydroxyl groups with phloroglucinol (3-substituted product), and 1.5 mol% of phloroglucinol.

[0128] (Example 3) Synthesis of phosphorus-containing phenol (Compound C)

[0129] A 300 mL 4-necked flask equipped with a stirrer, a thermometer, and a hydrochloric acid recovery device (a condenser connected to a water scrubber) was filled with 249.5 g of mesitylene, 12.6 g (0.1 mol) of phloroglucinol, 87.2 g (0.24 mol) of di-2,6-xylyl chlorophosphate, and 1.2 g (0.012 mol) of anhydrous magnesium chloride as a catalyst. The obtained mixed solution was slowly heated to 155°C while stirring. After reaching 155°C, it was reacted for 18 hours and the generated hydrogen chloride was collected. After cooling to 60°C, 60 g of ethyl acetate was added, acid washing, neutralization, and water washing were performed twice, and the solvent was removed to obtain 51.2 g of compound C.

[0130] The hydroxyl equivalent of compound C was 587 g / eq, and the phosphorus content was 9.0% by mass. Furthermore, GPC confirmed that the compound C contained 25 mol% of a compound (1-substituted product) formed by the reaction of one hydroxyl group of phloroglucinol with bis-2,6-xylyl chlorophosphate, 35 mol% of a compound (2-substituted product) formed by the reaction of two hydroxyl groups, and 40 mol% of a compound (3-substituted product) formed by the reaction of three hydroxyl groups.

[0131] (Comparative Example 1) Synthesis of Phosphorus-Containing Phenol (Compound D)

[0132] The synthesis was carried out according to the method described in International Publication WO2021 / 256351. Specifically, 1500 g of phosphorus oxychloride, 611 g of 2,6-dimethylphenol, and 1.2 g of magnesium chloride as a catalyst were filled into a 2-liter 4-necked flask equipped with a stirrer, a thermometer, and a hydrochloric acid recovery device (a condenser connected to a water scrubber).

[0133] The obtained mixed solution was stirred and slowly heated to 110°C for about 3 hours to react, and the generated hydrogen chloride (hydrochloric acid gas) was recovered by a water scrubber. Then, the pressure in the flask was slowly reduced to 12 kPa at 120°C to remove unreacted phosphorus oxychloride and phenol, and by-produced hydrogen chloride, thereby obtaining 1200 g of mono-2,6-dimethylphenyl dichlorophosphate.

[0134] A 2-liter 4-necked flask equipped with a stirrer, a thermometer, a dropping funnel, and a condenser was charged with 320 g of 2,3,5-trimethylhydroquinone, 135 g of pyridine as a hydrogen chloride scavenger, and 200 g of toluene as a solvent. In addition, 203 g of the above-mentioned mono-2,6-dimethylphenyl dichlorophosphate was charged into the dropping funnel.

[0135] The mixed solution in the 4-necked flask was heated to 20°C while stirring, and mono-2,6-dimethylphenyl dichlorophosphate in the dropping funnel was added dropwise over 2 hours while maintaining the same temperature (20°C). After the addition was completed, the mixture was heated to 65°C and stirred for 5 hours to obtain a reaction product. The obtained reaction product was washed with dilute hydrochloric acid and water, heated to 150°C, and the pressure was reduced to 2 kPa, and water, toluene, and low-boiling components were distilled off, and cooled to room temperature, thereby obtaining 330 g of a dark brown solid (Compound D) having the following structure.

[0136]

[0137] Examples 4 to 8, Comparative Examples 2 to 10

[0138] <Preparation of curable resin composition and production of cured product>

[0139] Varnish was prepared by mixing various ingredients in the ratio of Table 1, applied on a PET film, and dried in an oven at 130°C for 5 minutes to prepare a film of the resin composition. Next, the film was crushed to obtain a powder of the resin composition. Furthermore, the powder was sandwiched into a stainless steel mirror plate together with a separator, formed at 190°C for 90 minutes in a vacuum oven, and cured at 200°C for 5 hours to obtain a sample of a cured product. The cured product sample was used to evaluate the glass transition temperature and dielectric properties.

[0140] <Preparation of flame retardant test pieces>

[0141] Various components were blended in the ratios shown in Table 1 to prepare a varnish, and glass cloth (7628 type, model H258 manufactured by Nitto Bo Co., Ltd.) was impregnated with the resin varnish and then dried by heating at 130° C. for 5 minutes to obtain a prepreg.

[0142] The obtained 8 prepregs and the upper and lower copper foils (Mitsui Mining & Smelting Co., Ltd., 3EC-III, thickness 35 μm) were overlapped and vacuum pressed at 2 MPa under the temperature conditions of 130°C × 15 minutes + 190°C × 80 minutes to obtain a 1.6 mm thick laminate. The copper foil was etched and cut to obtain a flame retardant test piece. The flame retardancy was evaluated using the flame retardant test piece.

[0143] The formulations and results are shown in Table 1. The abbreviations in the table refer to the following compounds.

[0144] ESN-475V: Naphthalene-type epoxy resin manufactured by Nippon Steel Chemicals & Materials Co., Ltd. (epoxy equivalent: 325 g / eq)

[0145] SN-485: Naphthol resin manufactured by Nippon Steel Chemicals & Materials Co., Ltd. (hydroxyl equivalent: 210 g / eq)

[0146] TPP: Triphenyl phosphate manufactured by Daihachi Chemical Industry Co., Ltd. (phosphorus content: 9.5% by mass)

[0147] PX-200: Aromatic condensed phosphate ester manufactured by Daihachi Chemical Industry Co., Ltd. (phosphorus content: 9.02 mass%)

[0148] LC-950PM60: DOPO-BPA manufactured by ShinA Corporation (hydroxyl equivalent 570 g / eq, phosphorus content 10.9% by mass, solid content 60% by mass)

[0149] 2E4MZ: 2-ethyl-4-methylimidazole manufactured by Shikoku Chemicals Co., Ltd.

[0150] [Table 1]

[0151]

[0152] Industrial Applicability

[0153] The phosphorus-containing phenol compound of the present invention is useful for flame retardant plastic materials used in electrical and electronic products, OA equipment, communication equipment, building materials, etc., for example, thermosetting resins such as epoxy resins, and is particularly useful as a flame retardant material for reducing transmission loss due to the increase in the frequency of information processing in electronic equipment.

Claims

1. A phosphorus-containing phenol compound represented by the general formula (1): In the general formula (1), Ar is an aromatic ring group having 6 to 30 carbon atoms which may have a substituent, and R 1 Each independently represents hydrogen or a substituent represented by the following general formula (2), at least one R 1 Contains a substituent represented by the general formula (2), m is an integer of 3 to 6, In the general formula (2), R 2 and R 3 Each of n2 and n3 is independently a linear or branched alkyl group having 1 to 5 carbon atoms, and each of n2 and n3 is independently an integer of 0 to 5.

2. The phosphorus-containing phenol compound according to claim 1, wherein Ar is an aromatic ring group selected from a benzene skeleton, a naphthalene skeleton, a biphenyl skeleton and an anthracene skeleton.

3. The phosphorus-containing phenol compound according to claim 2, wherein Ar is a benzene ring.

4. The phosphorus-containing phenol compound according to claim 3, wherein m is 3.

5. The phosphorus-containing phenol compound according to claim 4, characterized in that Contains: 10 to 80 mol% of three ORs of the general formula (1) 1 Two Rs in the base 1 is hydrogen and one R 1 The compound is a substituent represented by the general formula (2), 5 to 50 mol% of the three OR 1 One R in the base 1 is hydrogen and two R 1 The compound is a substituent represented by the general formula (2), 1 to 50 mol% of the three OR 1 The Three Rs of Basics 1 A compound having a substituent represented by the general formula (2).

6. A method for producing a phosphorus-containing phenol compound according to any one of claims 1 to 5, characterized in that: 0.1 to 0.9 mol of the compound represented by the general formula (4) is reacted with 1 mol of the hydroxyl group of the compound represented by the general formula (3). In the general formula (3), Ar and m have the same meanings as in the general formula (1). In the general formula (4), X represents a halogen atom, R 2 , R 3 , n2, n3 have the same meanings as in the general formula (2). 7 . A curable resin composition comprising the phosphorus-containing phenol compound according to claim 1 and a curable resin.

8. A cured product obtained by curing the curable resin composition according to claim 7.

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