Polyphenylene ether resin composition, and polyphenylene ether cured product and method for producing the same

Abstract

To provide a polyphenylene ether resin composition which is excellent in dispersibility of a bromine-based flame retardant, and a polyphenylene ether cured product in which a bromine-based flame retardant is uniformly dispersed.SOLUTION: A polyphenylene ether resin composition contains a polyphenylene ether-based resin, a bromine-based flame retardant represented by the following general formula (1) and an organic solvent. The polyphenylene ether resin composition enables production of a polyphenylene ether cured product excellent in dispersibility of a bromine-based flame retardant, in which a bromine-based flame retardant is uniformly dispersed. In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S- or -SO2-, and n represents a real number.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a flame-retardant polyphenylene ether resin composition. [Background technology]

[0002] In recent years, with the increasing sophistication of electronic devices, dielectric properties such as low dielectric constant and low dielectric loss tangent are required for resin materials forming wiring boards. For this reason, thermosetting polyphenylene ether resins are used as resin materials. Since such resin materials are required to be flame retardant, polyphenylene ether resin compositions in which a bromine-based flame retardant is added to a polyphenylene ether resin have been proposed.

[0003] For example, Patent Documents 1 and 2 disclose polyphenylene ether resin compositions containing decabromodiphenylethane or ethylenebis(tetrabromophthalimide) as a bromine-based flame retardant. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2009 / 040921 [Patent Document 2] Japanese Patent Publication No. 2020-139122 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional polyphenylene ether resin compositions, the brominated flame retardant tends to settle, and constant stirring is required to ensure the composition is uniform, resulting in poor workability.Furthermore, it has been difficult to obtain a flame-retardant cured polyphenylene ether product in which the brominated flame retardant is uniformly dispersed in the polyphenylene ether.

[0006] The present invention has been made in view of the above-mentioned background art, and an object of the present invention is to provide a polyphenylene ether resin composition having excellent dispersibility of a brominated flame retardant, and further a cured polyphenylene ether product in which the brominated flame retardant is uniformly dispersed. [Means for solving the problem]

[0007] As a result of extensive investigations, the present inventors have found that the following invention can solve the above problems, and have completed the present invention. That is, the present invention relates to the following polyphenylene ether resin composition.

[0008] [1] A polyphenylene ether resin composition comprising a polyphenylene ether resin, a brominated flame retardant represented by the following general formula (1), and an organic solvent:

[0009] [ka] (In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO2-, and n represents a real number.)

[0010] [2] The polyphenylene ether resin composition according to item [1], characterized in that the polyphenylene ether resin is a compound having a repeating unit represented by the following general formula (2):

[0011] [ka] (In the formula, R 1 ~R 4 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, and n represents a real number.

[0012] [3] The polyphenylene ether resin composition according to item [1] or [2], characterized in that the brominated flame retardant represented by general formula (1) has a weight average molecular weight of 1,000 to 20,000 in terms of standard polystyrene as measured by gel permeation chromatography.

[0013] [4] The polyphenylene ether resin composition according to item [1] or [2], characterized in that the brominated flame retardant represented by general formula (1) has a weight-average molecular weight of 1,000 to 20,000 in terms of standard polystyrene as measured by gel permeation chromatography, and R is a 2,2-propylene group.

[0014] [5] The polyphenylene ether resin composition according to any one of items [1] to [4], further comprising an initiator.

[0015] [6] A cured polyphenylene ether product formed from the resin composition according to any one of items [1] to [5].

[0016] [7] A cured polyphenylene ether containing polyphenylene ether and a brominated flame retardant represented by the general formula (1), wherein the brominated flame retardant is uniformly dispersed in the cured polyphenylene ether.

[0017] [8] A method for producing a cured polyphenylene ether product, comprising heating, pressurizing, or hot-pressing the polyphenylene ether resin composition according to any one of items [1] to [4] in the presence of an initiator. [Effects of the Invention]

[0018] The polyphenylene ether resin composition of the present invention exhibits the effect of being superior in dispersibility of a brominated flame retardant compared to conventionally known polyphenylene ether resin compositions. Furthermore, by using the polyphenylene ether resin composition of the present invention, a cured polyphenylene ether product in which the brominated flame retardant is uniformly dispersed can be obtained. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be described in more detail below. One aspect of the present invention relates to a polyphenylene ether resin composition comprising a polyphenylene ether resin, a brominated flame retardant represented by the following general formula (1), and an organic solvent.

[0020] [ka] (In the formula, R represents an alkylene group having 1 to 6 carbon atoms, -S-, or -SO2-, and n represents a real number.)

[0021] In general formula (1), the alkylene group having 1 to 6 carbon atoms represented by R is not particularly limited, but examples thereof include a methylene group, an ethylene group, a 2,2-propylene group, a 2,2-butylene group, a hexadiene group, and a 1,1-cyclohexylene group. R is preferably a 2,2-propylene group in view of excellent heat resistance.

[0022] In the general formula (1), n ​​represents the average number of repeating units of the brominated flame retardant, and in the present invention, n represents a real number.

[0023] The n is preferably a real number of 3 to 40, more preferably a real number of 3 to 30, and even more preferably a real number of 4 to 15, in order to provide resins containing brominated flame retardants with excellent flame retardancy and heat resistance.

[0024] For example, when R is a 2,2-propylene group, the terminal structure is a 2-chloroethyl group, and n is 10, the theoretical average molecular weight of the brominated flame retardant of the present invention is 5,798.

[0025] The brominated flame retardant of the present invention preferably has a weight average molecular weight of 1,000 to 20,000, more preferably 2,000 to 18,000, and even more preferably 3,000 to 16,000, in terms of standard polystyrene, as measured by gel permeation chromatography, in order to impart excellent flame retardancy and heat resistance to a resin blended therewith.

[0026] The brominated flame retardant of the present invention represented by general formula (1) preferably has a ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) in terms of standard polystyrene, measured by gel permeation chromatography, of 1.0 to 4.0, more preferably 1.0 to 3.0, and even more preferably 1.0 to 2.5, in terms of obtaining higher heat resistance.

[0027] The method and conditions for measuring the weight-average molecular weight of the brominated flame retardant represented by general formula (1) of the present invention by gel permeation chromatography conformed to ISO 16014-3:2012 (JIS K 7252-3:2016). The method and conditions are described in more detail in the Examples.

[0028] The bromine content of the brominated flame retardant of the present invention represented by general formula (1) is preferably 50 to 60% by weight, more preferably 52 to 60% by weight, in that high flame retardancy is expected.

[0029] The amount of the brominated flame retardant represented by general formula (1) mixed with the polyphenylene ether resin is preferably 5 to 100 parts by weight, more preferably 10 to 80 parts by weight, and still more preferably 10 to 50 parts by weight, per 100 parts by weight of the polyphenylene ether resin.

[0030] The polyphenylene ether resin used in the present invention may be terminally modified. Examples of terminally modified polyphenylene ether resins include polyphenylene ether resins terminally modified with hydroxyl groups and polyphenylene ether resins terminally modified with a substituent having a carbon-carbon unsaturated bond.

[0031] The polyphenylene ether resin used in the present invention includes a compound having a repeating unit represented by the following general formula (2).

[0032] [ka] (In the formula, R 1 ~R 4 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, and n represents a real number.

[0033] In the compound having the repeating unit represented by general formula (2), R 1 ~R 4 The alkyl group having 1 to 6 carbon atoms represented by the formula (I) is not particularly limited, but examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, and the like, and among these, a methyl group is preferred.

[0034] In the compound having the repeating unit represented by general formula (2), R 1 ~R 4 The alkenyl group having 2 to 6 carbon atoms represented by the formula (I) is not particularly limited, but examples thereof include a vinyl group, an allyl group, an iso-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-pentenyl group, and a 1-hexenyl group.

[0035] An example of a compound having a repeating unit represented by general formula (2) is a compound having a structure represented by formula (3).

[0036] [ka] (In the formula, n represents a real number.)

[0037] An example of a compound having a repeating unit represented by general formula (2) is a compound having a structure represented by formula (4).

[0038] [ka] {where, R 5 ~R 12 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, and X are the same or different and each independently represent a hydrogen atom or a group represented by the formula (5):

[0039] [ka] (In the formula, a represents a real number of 0 to 10, Z represents an arylene group or a carbonyl group, and R 13 ~R 15 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. represents a group represented by Y represents —O— or a group represented by formula (6).

[0040] [ka] (In the formula, R 16 ~R 23 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, and W represents an alkylene group having 1 to 6 carbon atoms. m and n each independently represent a real number.

[0041] In general formula (4), R 5 ~R 12The alkyl group having 1 to 6 carbon atoms represented by the formula (I) is not particularly limited, but examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, and the like, and among these, a methyl group is preferred.

[0042] In general formula (4), R 5 ~R 12 The alkenyl group having 2 to 6 carbon atoms represented by the formula (I) is not particularly limited, but examples thereof include a vinyl group, an allyl group, an iso-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-pentenyl group, and a 1-hexenyl group.

[0043] In the general formula (5), the arylene group represented by Z is not particularly limited, but examples thereof include a phenylene group.

[0044] In general formula (5), R 13 ~R 15 The alkyl group having 1 to 6 carbon atoms represented by the formula (I) is not particularly limited, but examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, and the like, and among these, a methyl group is preferred.

[0045] In general formula (6), R 16 ~R 23 The alkyl group having 1 to 6 carbon atoms represented by the formula (I) is not particularly limited, but examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, and the like, and among these, a methyl group is preferred.

[0046] In general formula (6), R 16 ~R 23The alkenyl group having 2 to 6 carbon atoms represented by the formula (I) is not particularly limited, but examples thereof include a vinyl group, an allyl group, an iso-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-pentenyl group, and a 1-hexenyl group.

[0047] In general formula (6), the alkylene group having 1 to 6 carbon atoms represented by W is not particularly limited, but examples thereof include a methylene group, an ethylene group, a 2,2-propylene group, a 2,2-butylene group, a hexadiene group, and a 1,1-cyclohexylene group.

[0048] The weight average molecular weight (Mw) of the polyphenylene ether resin of the present invention, measured by gel permeation chromatography in terms of standard polystyrene, is not particularly limited, and examples thereof include 1,000 to 120,000, 1,000 to 50,000, 1,000 to 20,000, 1,000 to 10,000, and 1,000 to 5,000.

[0049] The polyphenylene ether resin composition of the present invention contains an organic solvent. Examples of the organic solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, butanol, 2-propanol, 2-methoxyethanol, 2-ethoxyethanol, tetrahydrofuran, toluene, xylene, N,N-dimethylformamide, N-methyl-2-pyrrolidone, n-hexane, and cyclohexane. Among these, methyl ethyl ketone, cyclohexanone, toluene, xylene, N-methyl-2-pyrrolidone, and cyclohexane are preferred. These organic solvents may be used alone or in combination of two or more. The amount of the organic solvent to be mixed with the polyphenylene ether resin may be 30 to 1,000 parts by weight, preferably 40 to 500 parts by weight, per 100 parts by weight of the polyphenylene ether resin.

[0050] The polyphenylene ether resin composition of the present invention may further contain other resins as needed, as long as the effects of the resin composition can be exhibited. Examples of other resins include bismaleimide resins, bismaleimide-triazine resins, epoxy resins, benzocyclobutene resins, polytetrafluoroethylene resins, and acrylic resins.

[0051] The epoxy resin refers to a compound having an epoxy group in the molecule, and specific examples thereof include bisphenol A epoxy compounds, bisphenol F epoxy compounds, dicyclopentadiene epoxy compounds, phenol novolac epoxy compounds, naphthalene epoxy compounds, and biphenyl epoxy compounds.

[0052] The initiator of the present invention is not particularly limited as long as it is a compound that can generate radicals for crosslinking the polyphenylene ether resin composition, and examples thereof include peroxides (particularly organic peroxides). Specific examples include benzoyl peroxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, di-t-butyl peroxide, t-butylcumyl peroxide, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, dicumyl peroxide, di-t-butylperoxyisophthalate, t-butylperoxybenzoate, 2,2-bis(t-butylperoxy)butane, 2,2-bis(t-butylperoxy)octane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, di(trimethylsilyl)peroxide, and trimethylsilyltriphenylsilyl peroxide.

[0053] The amount of initiator mixed with the polyphenylene ether resin is preferably 1 to 10 parts by weight, more preferably 2 to 8 parts by weight, and even more preferably 3 to 6 parts by weight, per 100 parts by weight of the polyphenylene ether resin.

[0054] The polyphenylene ether resin composition of the present invention may further contain other additives as needed, such as a crosslinking agent, a curing catalyst, an inorganic filler, etc., as long as the effects of the resin composition can be exhibited.

[0055] Examples of the crosslinking agent include triallyl isocyanurate, triallyl cyanurate, diallyl monoalkyl isocyanurate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, triallyl trimellitate, and polyfunctional styrene compounds.

[0056] Examples of polyfunctional styrene compounds include bisvinylphenylmethane, 1,2-bis(m-vinylphenyl)ethane, 1,2-bis(p-vinylphenyl)ethane, 1-(p-vinylphenyl)-2-(m-vinylphenyl)ethane, 1,3-bis(m-vinylphenylethyl)benzene, 1,3-bis(p-vinylphenylethyl)benzene, 1-(p-vinylphenylethyl)-3-(m-vinylphenylethyl)benzene, 1,4-bis(m-vinylphenylethyl)benzene, 1,4-bis(p-vinylphenylethyl)benzene, 1,6-(bisvinylphenyl)hexane, and divinylbenzene polymers (oligomers) having vinyl groups in the side chains.

[0057] The curing catalyst is not particularly limited, but examples thereof include tertiary amines such as triethylamine and triethanolamine, and imidazoles such as 2-ethyl-4-imidazole and 4-methylimidazole, etc. These may be used alone or in combination of two or more.

[0058] The inorganic filler is not particularly limited, but examples thereof include metal oxides, nitrides, silicides, borides, etc., such as silica, boron nitride, wollastonite, talc, kaolin, clay, mica, alumina, zirconia, and titania.

[0059] The brominated flame retardant represented by general formula (1) of the present invention is not particularly limited, but as an example, it can be produced by heating a mixture containing a compound represented by the following general formula (7), a compound represented by the following general formula (8), a base, a radical trapping agent, and a solvent in the range of 110 to 150°C while stirring.

[0060] [ka] (In the formula, R represents a C1 to C6 alkylene group, -S-, or -SO2-.)

[0061] [ka] (In the formula, X and Y represent halogen atoms.)

[0062] The compound represented by the general formula (7) is not particularly limited, but examples thereof include tetrabromobisphenol A, tetrabromobisphenol F, and bis(4'-hydroxy-3',5'-dibromophenyl)sulfone. Among these, tetrabromobisphenol A is preferred because it can provide a brominated flame retardant with excellent heat resistance.

[0063] In the compound represented by the general formula (8), the halogen atoms represented by X and Y are not particularly limited, but examples thereof include chlorine, bromine, and iodine. Among these, chlorine is preferred in that a bromine-based flame retardant having excellent heat resistance can be obtained.

[0064] The compound represented by the general formula (8) is not particularly limited, but examples thereof include ethane dichloride, ethane dibromide, ethane diiodide, 1-bromo-2-chloroethane, 1-chloro-2-iodoethane, and 1-bromo-2-iodoethane.

[0065] In the production of the brominated flame retardant represented by general formula (1) of the present invention, the base is not particularly limited, and examples thereof include lithium hydroxide, potassium hydroxide, sodium hydroxide, cesium hydroxide, lithium hydrogen carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, cesium hydrogen carbonate, lithium carbonate, potassium carbonate, sodium carbonate, cesium carbonate, calcium hydroxide, strontium hydroxide, barium hydroxide, etc. Among these, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, or potassium hydrogen carbonate is preferred, and potassium carbonate is more preferred, in that a halogenated polymer having excellent heat resistance can be obtained.

[0066] In the production of the brominated flame retardant of the present invention represented by general formula (1), the solvent is not particularly limited as long as it does not react with the substrate, and examples thereof include aprotic polar solvents.

[0067] The aprotic polar solvent is not particularly limited, but examples thereof include tetrahydrofuran, dioxane, pyridine, N-methylpyrrolidone, propylene carbonate, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, etc. Among these, N-methylpyrrolidone, dimethylacetamide, dimethylformamide, and dimethyl sulfoxide are preferred in that they can produce halogenated polymers with excellent heat resistance.

[0068] In the production of the brominated flame retardant of the present invention represented by general formula (1), the reaction temperature is preferably in the range of 110 to 150°C, more preferably in the range of 120 to 145°C.

[0069] The radical trapping agent is not particularly limited, but examples thereof include at least one radical trapping agent selected from the group consisting of phenol-based radical trapping agents, quinone-based radical trapping agents, phosphite-based radical trapping agents, amine-based radical trapping agents, and sulfur-based radical trapping agents. More specifically, for example, 4-methoxyphenol, 6-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butylphenol, 2-tert-butyl-4-methoxyphenol, 4-tert-butylphenol, 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol (also known as dibutylhydroxytoluene), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 3,6-dihydroxybenzonorbornane, 2,2'-methylenebis(6-cyclohexyl-p-cresol), hydroquinone, tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 1,4-benzoquinone, 2-tert-butyl-1,4-benzoquinone, 4-tert-butylcatechol, pentaerythritol, tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], diphenylamine, N,N-diethylhydroxylamine, ammonium nitrosophenylhydroxylamine, 2,2,6,6-tetramethylpiperidine-1-oxyl, 2-benzimidazolethiol, phenothiazine, didodecyl 3,3'-thiodipropionate, dioctadecyl 3,3'-thiodipropionate, triethyl phosphite, trihexyl phosphite, tris(1,1,1-hexafluoro-2-propyl) phosphite, triphenyl phosphite, tris(2-methylphenyl) phosphite, tris(4-methylphenyl) phosphite, tris(4-nonylphenyl) phosphite, pentaerythritol bis(2,4-di-tert-butylphenyl phosphite), and tris(2,4-di-tert-butylphenyl) phosphite.

[0070] In the production of the brominated flame retardant represented by general formula (1) of the present invention, the mixing ratio of the compound represented by general formula (7) above to the compound represented by general formula (8) above is preferably 0.8 to 2.0 molar parts, more preferably 1.0 to 1.8 molar parts, and still more preferably 1.2 to 1.5 molar parts of the compound represented by general formula (8) above per 1 molar part of the compound represented by general formula (7).

[0071] In the production of the brominated flame retardant represented by general formula (1) of the present invention, the amount of the base used is preferably 0.8 to 2.5 molar parts, more preferably 0.9 to 2.0 molar parts, and still more preferably 1.0 to 1.8 molar parts, relative to 1 molar part of the compound represented by general formula (7).

[0072] In the production of the brominated flame retardant represented by general formula (1) of the present invention, the amount of the radical trapping agent used is preferably 0.001 to 10 parts by mass, more preferably 0.005 to 8 parts by mass, and still more preferably 0.01 to 5 parts by mass, relative to 100 parts by mass of the compound represented by general formula (7).

[0073] In the production of the brominated flame retardant represented by general formula (1) of the present invention, the amount of the solvent used is preferably 200 to 2,000 parts by mass, more preferably 250 to 900 parts by mass, and still more preferably 250 to 500 parts by mass, relative to 100 parts by mass of the compound represented by general formula (7).

[0074] The polyphenylene ether resin composition of the present invention can be heated, pressurized, or hot-pressed in the presence of an initiator to give a flame-retardant cured polyphenylene ether product (hereinafter sometimes abbreviated as "cured product") in which the brominated flame retardant of general formula (1) is uniformly dispersed.

[0075] The polyphenylene ether resin composition of the present invention can be used as a resin composition for forming an insulating layer of a circuit board such as a printed circuit board, etc. In particular, by utilizing the advantage that an insulating layer having a low dielectric constant and a low dielectric loss tangent can be obtained, the polyphenylene ether resin composition can be suitably used as a resin composition for forming an insulating layer of a high-frequency circuit board.

[0076] The substrate material is not particularly limited, but examples include polymeric materials such as polyimide (PI), bismaleimide (BMI), polybutadiene (PB), polystyrene (PS), polytetrafluoroethylene (PTFE), and liquid crystal polymer (LCP), as well as inorganic materials such as glass, silicon, and silicon oxide.

[0077] The polyphenylene ether resin composition of the present invention can be impregnated into cloth or nonwoven fabric of various organic or inorganic materials, dried, and used as a prepreg, which is a substrate material. Examples of inorganic cloth or nonwoven fabric include glass cloth and glass nonwoven fabric. Furthermore, a laminate having a conductor foil on the surface can be produced by overlapping the prepreg with a conductor foil such as copper foil and hot pressing it.

[0078] The temperature conditions during hot-press processing are not particularly limited as long as they allow curing by a thermal aggregation reaction in the prepreg based on the initiator. While such conditions are not particularly limited, a temperature of 120 to 230°C is preferred, with 140 to 210°C being more preferred. The pressure conditions during hot-press processing are not particularly limited as long as they allow bonding of the cured prepreg to the copper foil, with 10 to 80 kN being preferred, with 20 to 70 kN being more preferred. [Example]

[0079] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples in any way. <Measurement of weight average molecular weight> The polymer samples synthesized in the examples were measured using a gel permeation chromatography system (Tosoh Corporation, HLC-8320GPC) connected to a molecular weight measurement column (Tosoh Corporation, TSKgel® SuperAW2500+3000+5000) at a flow rate of 0.6 mL / min with chloroform eluent at 40°C and UV (254 nm) detection. Furthermore, the weight average molecular weight of the sample was measured using standard polystyrene. Other measurements were performed in accordance with JIS-K-7252.

[0080] <Weight loss temperature measurement> As an index of the thermal stability of the halogen-containing polymer, the weight loss temperature was measured under the following conditions. Analytical equipment: Rigaku ThermoPlus TG8120 Measurement conditions: 10 mg of sample, heated in air at a rate of 10°C / min

[0081] <Synthesis of brominated flame retardants> Synthesis Example 1 A 5-L cylindrical glass separable flask equipped with a stirrer and reflux condenser was charged with 800.0 g (1.471 mol) of tetrabromobisphenol A, 254.1 g (1.839 mol) of potassium carbonate, 4.00 g (26.6 mmol) of 4-tert-butylphenol, 4.01 g (6.19 mmol) of tris(2,4-di-tert-butylphenyl) phosphite, and 2100 g of dimethylformamide. The mixture was heated to 130°C with stirring. At this temperature, 186.3 g (1.883 mol) of ethane dichloride was added, and the mixture was stirred at 130°C for another 4 hours and then allowed to cool to room temperature. Methanol was added to the reaction mixture to precipitate a solid. The precipitated solid was filtered, washed with water, and then dried. A white solid brominated flame retardant (a) was obtained in a 90% yield. The weight average molecular weight of the resulting brominated flame retardant (a) was 10,600, and the 5% weight loss temperature was 367°C.

[0082] Synthesis Example 2 The same procedure as in Synthesis Example 1 was carried out, except that the amount of ethane dichloride used was 218.3 g (2.206 mol), to obtain a white solid brominated flame retardant (b) in an 81% yield. The weight-average molecular weight of the obtained brominated flame retardant (b) was 3,400, and the 5% weight loss temperature was 374°C.

[0083] <Evaluation of flame retardant dispersibility> The materials used in the evaluation are shown below. Brominated flame retardant (c): Decabromodiphenylethane Brominated flame retardant (d): Ethylene bis(tetrabromophthalimide)

[0084] Example 1 To 100 parts by weight of polyphenylene ether resin (SA90 manufactured by SABIC), 70 parts by weight of toluene was added, and the mixture was stirred and mixed with a magnetic stirrer while heating to 80°C to obtain a uniform resin solution. After the resin solution was allowed to cool to room temperature, 20 parts by weight of a brominated flame retardant (a) was added, and the mixture was stirred and mixed with a magnetic stirrer to obtain a polyphenylene ether resin composition.

[0085] Example 2 To 40 parts by weight of polyphenylene ether resin (SABIC SA90), 60 parts by weight of bisphenol A diglycidyl ether (BADGE) and 40 parts by weight of toluene were added, and the mixture was stirred and mixed with a magnetic stirrer while heating to 80°C to obtain a uniform resin solution. After the resin solution was allowed to cool to room temperature, 20 parts by weight of a brominated flame retardant (a) was added, and the mixture was stirred and mixed with a magnetic stirrer to obtain a polyphenylene ether resin composition.

[0086] Comparative Example 1 A polybutadiene resin composition was obtained in the same manner as in Example 1, except that the brominated flame retardant (a) was replaced with the brominated flame retardant (c).

[0087] Comparative Example 2 A polybutadiene resin composition was obtained in the same manner as in Example 1, except that the brominated flame retardant (a) was replaced with the brominated flame retardant (d).

[0088] Comparative Example 3 A polybutadiene resin composition was obtained in the same manner as in Example 2, except that the brominated flame retardant (a) was replaced with the brominated flame retardant (c).

[0089] Comparative Example 4 A polybutadiene resin composition was obtained in the same manner as in Example 2, except that the brominated flame retardant (a) was replaced with the brominated flame retardant (d).

[0090] The polyphenylene ether resin compositions obtained in Examples 1 and 2 and Comparative Examples 1 to 4 were allowed to stand for 24 hours, and if no sedimentation of the brominated flame retardant was observed by visual inspection, the dispersibility was rated as "Good." If sedimentation of the brominated flame retardant was observed, the dispersibility was rated as "Poor." The results are shown in Table 1.

[0091] [Table 1]

[0092] Example 3 To 80 parts by weight of polyphenylene ether resin (SABIC SA9000), 20 parts by weight of triallyl isocyanurate (TAIC) and 80 parts by weight of toluene were added, and the mixture was stirred and mixed with a magnetic stirrer while heating to 80°C to obtain a uniform resin solution. After the resin solution was allowed to cool to room temperature, 20 parts by weight of a brominated flame retardant (a) was added, and the mixture was stirred and mixed with a magnetic stirrer to obtain a polyphenylene ether resin composition.

[0093] Example 4 To 80 parts by weight of polyphenylene ether resin (SABIC SA9000), 20 parts by weight of TAIC and 80 parts by weight of toluene were added, and the mixture was stirred and mixed with a magnetic stirrer while heating to 80°C to obtain a uniform resin solution. After the resin solution was allowed to cool to room temperature, 30 parts by weight of brominated flame retardant (a) was added, and the mixture was stirred and mixed with a magnetic stirrer to obtain a polyphenylene ether resin composition.

[0094] Example 5 A polybutadiene resin composition was obtained in the same manner as in Example 3, except that the brominated flame retardant (a) was replaced with the brominated flame retardant (b).

[0095] Comparative Example 5 A polybutadiene resin composition was obtained in the same manner as in Example 3, except that the brominated flame retardant (a) was replaced with the brominated flame retardant (c).

[0096] Comparative Example 6 A polybutadiene resin composition was obtained in the same manner as in Example 3, except that the brominated flame retardant (a) was replaced with the brominated flame retardant (d). The polyphenylene ether resin compositions obtained in Examples 3 and 4 and Comparative Examples 5 and 6 were allowed to stand for 2 hours, and if no sedimentation of the brominated flame retardant was observed by visual inspection, the dispersibility was rated as "Good." If sedimentation of the brominated flame retardant was observed, the dispersibility was rated as "Poor." The results are shown in Table 2.

[0097] [Table 2]

[0098] Example 6 To 70 parts by weight of polyphenylene ether resin (SABIC SA9000), 30 parts by weight of TAIC and 70 parts by weight of toluene were added, and the mixture was stirred and mixed with a magnetic stirrer while heating to 80°C to obtain a uniform resin solution. After the resin solution was allowed to cool to room temperature, 20 parts by weight of brominated flame retardant (a) was added, and the mixture was stirred and mixed with a magnetic stirrer to obtain a polyphenylene ether resin composition.

[0099] Comparative Example 7 A polybutadiene resin composition was obtained in the same manner as in Example 6, except that the brominated flame retardant (a) was replaced with the brominated flame retardant (c).

[0100] Comparative Example 8 A polybutadiene resin composition was obtained in the same manner as in Example 6, except that the brominated flame retardant (a) was replaced with the brominated flame retardant (d). The polyphenylene ether resin compositions obtained in Example 6 and Comparative Examples 7 and 8 were allowed to stand for 4 hours, and if no sedimentation of the brominated flame retardant was observed by visual inspection, the dispersibility was rated as "Good." If sedimentation of the brominated flame retardant was observed, the dispersibility was rated as "Poor." The results are shown in Table 3.

[0101] [Table 3] The results in Tables 1 to 3 show that the polyphenylene ether resin composition of the present invention is superior to conventional polyphenylene ether resin compositions in dispersibility of brominated flame retardants.

[0102] <Evaluation of the dielectric constant, dielectric dissipation factor, linear expansion coefficient, and flame retardant dispersibility of the cured product> Example 7 To the polyphenylene ether resin composition of Example 3, 0.5 parts by weight of α,α'-bis(t-butylperoxy-m-isopropyl)benzene (Perbutyl P, manufactured by NOF Corporation) was added as an initiator to 80 parts by weight of the polyphenylene ether resin. The mixture was stirred and mixed using a magnetic stirrer. 1.4 g of the resulting resin composition was applied to a PTFE film and vacuum-dried overnight at room temperature in a vacuum oven. A metal frame (80 mm x 60 mm x 0.25 mm) was placed on the PTFE film, and the mixture was pressurized and heated using a hydraulic vacuum heating press, IMC-11FD (manufactured by Imoto Machinery Co., Ltd.), to obtain a cured product. The curing conditions were atmospheric pressure, 150°C, 60 kN, and maintained for 30 minutes. The pressure was then released, and the temperature was increased and maintained under reduced pressure at 195°C and 40 kN for 2 hours to produce a cured product.

[0103] Comparative Example 9 A cured product was prepared in the same manner as in Example 7, except that the polyphenylene ether resin composition of Comparative Example 5 was used instead of the polyphenylene ether resin composition of Example 3. <Measurement of dielectric constant and dielectric loss tangent> The produced cured product was measured using a TE cavity resonator (manufactured by Keycom Co., Ltd.) at a frequency of 28 GHz. <Measurement of linear expansion coefficient> The cured products were measured using a TMAQ400EM (manufactured by TA Instruments) with a tensile probe at a heating rate of 5°C / min, a measurement temperature range of room temperature to 230°C, and a load of 0.1 N. The measurement method involved heating from room temperature to 230°C, cooling to room temperature again, and then heating to 230°C; the linear expansion coefficient from room temperature to 230°C was defined as α. <Flame retardant dispersibility> The cured product was visually inspected to see if it was cloudy overall and the flame retardant was uniformly dispersed, and was evaluated as "Good." Partial cloudiness or uneven dispersion was evaluated as "Poor." The results are shown in Table 4.

[0104] [Table 4]

Claims

1. A polyphenylene ether resin composition comprising a polyphenylene ether resin, a brominated flame retardant represented by the following general formula (1), and an organic solvent: 【Chemistry 1】 (wherein R represents an alkylene group having 1 to 6 carbon atoms, —S—, or —SO ２ indicates -, and n indicates a real number.)

2. 2. The polyphenylene ether resin composition according to claim 1, wherein the polyphenylene ether resin is a compound having a repeating unit represented by the following general formula (2): 【Chemistry 2】 (In the formula, R １ ~R ４ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, and n represents a real number.

3. 3. The polyphenylene ether resin composition according to claim 1, wherein the brominated flame retardant represented by general formula (1) has a weight average molecular weight of 1,000 to 20,000 in terms of standard polystyrene, as measured by gel permeation chromatography.

4. 3. The polyphenylene ether resin composition according to claim 1, wherein the brominated flame retardant represented by general formula (1) has a weight average molecular weight of 1,000 to 20,000 in terms of standard polystyrene as measured by gel permeation chromatography, and R is a 2,2-propylene group.

5. The polyphenylene ether resin composition according to claim 1 or claim 2, further comprising an initiator.

6. A cured polyphenylene ether product formed from the resin composition according to claim 5.

7. A cured polyphenylene ether containing polyphenylene ether and a brominated flame retardant represented by the general formula (1), wherein the brominated flame retardant is uniformly dispersed in the cured polyphenylene ether.

8. A method for producing a cured polyphenylene ether product, comprising heating, pressurizing, or hot-pressing the polyphenylene ether resin composition according to claim 1 or 2 in the presence of an initiator.

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