JP2004107374A - Flame-retardant resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive resin composition which does not contain a halogen compound, excels in heat resistance and mechanical properties, and has a high degree of flame retardance preferred from the environmental viewpoint and excellent electrical characteristics. <P>SOLUTION: The flame-retardant resin composition which can be used in a high frequency band of ≥1 GHz comprises a resin (a) and a specific phosphazene compound (b) in an amount of the phosphazene compound of the component (b) of 1-35 wt.% based on 100 wt.% total amount of the components (a) and (b). <P>COPYRIGHT: (C)2004,JPO

Description

【００２０】
ＦＲ２：式（５）で表される環状ホスファゼン三量体であり、^３１Ｐ　ＮＭＲにおいて式（５）で表されるホスファゼン以外のピークが観測されないもの。
【００２１】
【化６】

【００２２】
ＦＲ３：式（６）で表される環状ホスファゼン三量体であり、^３１Ｐ　ＮＭＲにおいて式（６）で表されるホスファゼン以外のピークが観測されないもの。
【００２３】
【化７】

【００２４】
ＦＲ４：式（７）で表される環状ホスファゼン三量体であり、^３１Ｐ　ＮＭＲにおいて式（７）で表されるホスファゼン以外のピークが観測されないもの。
【００２５】
【化８】

【００２６】
ＦＲ５：式（８）で表される環状ヘキサフェノキシホスファゼン三量体で、^３１Ｐ　ＮＭＲにおいて式（８）で表される環状ヘキサフェノキシホスファゼン以外のピークが観測されないもの。
【００２７】
【化９】

【００２８】
ＦＲ６：トリフェニルホスフェート
実施例および比較例の樹脂組成物物性評価は以下の方法で行った。
（１）難燃性：ＵＬ−９４垂直燃焼試験に基づき、長さ１２８ｍｍ×幅１２．８ｍｍ×厚さ１．６ｍｍの成形試験片を用いて行い、１０回接炎時の合計燃焼時間と燃焼時の滴下物による綿着火の有無により、Ｖ−０、Ｖ−１、Ｖ−２、規格外の四段階に分類した。評価基準を以下に示し、消炎時間は短いほど難燃性が優れていることを示す。
【００２９】
Ｖ−０：下記の条件を全て満たす。
（Ａ）試験片５本を１本につき二回ずつ、合計１０回の接炎後からの消炎時間の合計が５０秒以内。
（Ｂ）試験片５本を一本につき二回ずつ接炎を行い、それぞれの接炎後からの消炎時間が５秒以内。
（Ｃ）すべての試験片で滴下物による、３００ｍｍ下の脱脂綿への着火がない。
（Ｄ）すべての試験片で、二回目の接炎後のグローイングは３０秒以内。
（Ｅ）すべての試験片で、クランプまでフレーミングしない。
【００３０】
Ｖ−１：下記の条件を全て満たす。
（Ａ）試験片５本を１本につき二回ずつ、合計１０回の接炎後からの消炎時間の合計が２５０秒以内。
（Ｂ）試験片５本を一本につき二回ずつ接炎を行い、それぞれの接炎後からの消炎時間が３０秒以内。
（Ｃ）すべての試験片で滴下物による、３００ｍｍ下の脱脂綿への着火がない。
（Ｄ）すべての試験片で、二回目の接炎後のグローイングは６０秒以内。
（Ｅ）すべての試験片で、クランプまでフレーミングしない。
【００３１】
Ｖ−２：下記の条件を全て満たす。
（Ａ）試験片５本を１本につき二回ずつ、合計１０回の接炎後からの消炎時間の合計が２５０秒以内。
（Ｂ）試験片５本を一本につき二回ずつ接炎を行い、それぞれの接炎後からの消炎時間が３０秒以内。
（Ｃ）試験片５本のうち、少なくとも一本、滴下物による、３００ｍｍ下の脱脂綿への着火がある。
（Ｄ）すべての試験片で、二回目の接炎後のグローイングは６０秒以内。
（Ｅ）すべての試験片で、クランプまでフレーミングしない。
【００３２】
（２）誘電特性
厚さ約２ｍｍの１５０×１５０ｍｍの成形片を用いて、比誘電率及び誘電正接をトリプレート法により、周波数１ギガヘルツ（ＧＨｚ）、５ＧＨｚ及び１０ＧＨｚにて測定した。
【００３３】
【実施例１〜４、比較例１〜２】
各成分を表１に示す割合で混合し、加熱シリンダーの最高温度を３００℃に設定したスクリュー直径２５ｍｍの二軸押出機に供給して、スクリュー回転数３００ｒｐｍで溶融混練りし、ストランドを冷却裁断して樹脂組成物ペレットを得た。
次に、得られた樹脂組成物ペレットを、射出成形により２４０〜２９０℃にて物性試験片を成形し、上記試験法により物性試験を行い、表１の結果を得た。
【００３４】
【表１】

【００３５】
【発明の効果】
本発明は、ハロゲン化合物を含まず、電気特性に優れ、環境上好ましい、高度の難燃性を有する樹脂組成物を提供する。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flame-retardant resin composition having excellent flame retardancy and excellent electrical properties.
[0002]
[Prior art]
In recent years, in the field of electric and electronic devices, as the frequency band used becomes a higher frequency region, it is required that the resin composition has high flame retardancy and has more excellent electric characteristics. I have.
Heretofore, flame retarding techniques such as addition of a halogen compound and antimony trioxide have been conventionally used as flame retarding of a flammable synthetic resin (for example, see Patent Document 1). These are not preferred from the viewpoint of environmental protection and toxicity, and the use of halogen-based flame retardants generates halogen-based gas, which may be a factor in deteriorating the electrical properties of the resin composition. In the field of electronic materials and the like, from the viewpoint of obtaining excellent electrical characteristics, there is a demand for a flame-retardant method that does not cause deterioration of the electrical characteristics.
[0003]
As an alternative material that does not contain such a halogen-based flame retardant or metal oxide, flame retardation using a phosphorus-based flame retardant has been studied. For example, a method using red phosphorus (for example, see Patent Document 2), A method using a phosphate ester (for example, see Patent Documents 3 and 4) and the like are disclosed. However, the method using red phosphorus has many problems such that it reacts with a small amount of water to generate toxic phosphine and also generates corrosive phosphoric acid. Further, phosphate esters have many problems such as a decrease in hydrolysis resistance and a decrease in moldability due to plasticization.
[0004]
Although a method of increasing the blending ratio of the filler (for example, see Patent Document 5) has been proposed, addition of a large amount of the filler makes the resin composition extremely brittle, and also has an extreme surface property and moldability. It is not preferable because it deteriorates.
In addition, phosphazene-based compounds have been reported as flame retardants for resins. For example, flame-retardant epoxy compositions in which a phosphazene compound is added to an epoxy resin (for example, see Patent Documents 6 and 7) and phenoxy phosphazene are ABS-based. A resin composition added to a resin (for example, see Patent Document 8), a flame-retardant resin composition obtained by adding a phosphazene compound to a polycarbonate resin (for example, see Patent Document 9), and the like are reported. However, in order to obtain sufficient flame retardancy, it is necessary to add a large amount of a flame retardant, and there is a problem such as a decrease in heat resistance.
[0005]
In the field of electric and electronic materials, a resin composition containing an epoxy resin is widely used because it has good electric properties, is easy to handle, and is inexpensive. However, those that are used in fields where it is essential to have a low dielectric constant and a low dielectric loss tangent, such as printed circuit boards and sealing materials, are expensive bismaleimides and epoxy resins such as chlorine and bromine. Halogenated epoxy resins containing the halogen element (1), those using a halogen compound as a flame retardant for the epoxy resin, and thermosetting polyphenylene ethers are mainly used. Although thermosetting polyphenylene ether has good electrical properties, the fluidity of the resin composition is extremely poor, and the processability is poor. Therefore, an inexpensive resin composition that does not contain a halogen that adversely affects the environment, has good processability, and has excellent electrical characteristics is desired.
[0006]
Phosphazene compounds are known as flame retardants that are said to provide an excellent flame retardant effect, but when cyclophenoxy phosphazene trimer or cyclo (o-chlorophenoxy) phosphazene trimer is used as a flame retardant for an epoxy resin composition, It is disclosed that in a low frequency region of 1 kilohertz (KHz), better electrical characteristics are provided as compared with those without using a flame retardant (for example, see Patent Document 10). However, at 1 megahertz (MHz), the effect of adding cyclophenoxy phosphazene trimer or cyclo (o-chlorophenoxy) phosphazene trimer is small. There is no description about a high frequency region of 1 GHz or more.
[0007]
[Patent Document 1]
JP-A-60-255844 [Patent Document 2]
JP-A-9-227765 [Patent Document 3]
Japanese Patent Application Laid-Open No. 9-235449 [Patent Document 4]
JP-A-11-43536 [Patent Document 5]
Japanese Patent Application Laid-Open No. 7-82343 [Patent Document 6]
JP-A-10-259292 [Patent Document 7]
Japanese Patent Publication No. 6-53787 [Patent Document 8]
JP 2001-280950 A [Patent Document 9]
JP-A-51-37149 [Patent Document 10]
JP-A-8-225714
[Patent Document 11]
Japanese Patent Publication No. Hei 3-73590 [Patent Document 12]
JP-A-9-183864 [Patent Document 13]
JP-A-11-181429 [Patent Document 14]
Japanese Patent Application Laid-Open No. 2001-64292 [Non-Patent Document 1]
James E. Mark, Harry R. Allcock, Robert West, "Inorganic Polymers," Precision-Hall, International, Inc. , 1992, p. 61-140
[0008]
[Problems to be solved by the invention]
The present invention provides an inexpensive resin composition which does not contain a halogen compound, has excellent heat resistance and mechanical properties, is environmentally preferable, has high flame retardancy, and has excellent electrical properties.
[0009]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above problems, and as a result, by including a cyclic phosphazene compound having at least one aryloxy group in a resin composition as a flame retardant, excellent flame retardancy and electrical properties. And reached the present invention.
Hereinafter, the present invention will be described in detail.
[0010]
The resin as the component (a) used in the present invention is not particularly limited, but may be used together with, for example, polyphenylene ether, polystyrene-modified polyphenylene ether, polyamide, polystyrene, high-impact polystyrene (HIPS). , ABS resin, polyethylene, methacrylic resin, polyethylene terephthalate, polyacetal, polybutadiene, polypropylene, polybutylene terephthalate, polycarbonate, thermoplastic resin such as alloy composed of polycarbonate and ABS resin, epoxy resin, phenolic resin, urea resin, melamine resin, Guanamine resin, alkyd resin, unsaturated polyester resin, vinyl ester, diallyl phthalate, silicone resin, urethane resin, furan resin, ketone resin, Thermosetting resins such as styrene resin, styrylpyridine resin, and triazine resin, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyimide resin, polyetheretherketone, liquid crystal polymer, and syndiotactic polystyrene An engineering resin may be used, and each may be used alone or as two or more alloys.
[0011]
In order to obtain good electrical properties, polyphenylene ether, polypropylene, polystyrene, polycarbonate, polyimide, polysulfone, epoxy resin, polyphenylene sulfide, polyethersulfone, syndiotactic polystyrene, liquid crystal polymer, etc. It is preferably used.
The phosphazene compound (b) used in the present invention is a known compound (for example, see Non-Patent Document 1), and a cyclic phosphazene compound represented by the general formula (1) (where n is an integer of 1 to 8): A chain phosphazene having a chain structure represented by the general formula (3) is used. Among them, a cyclic phosphazene compound represented by the general formula (1) (where n is an integer of 1 to 8) is preferable, and particularly, a 6-membered ring and an 8-membered ring in which n = 3, 4 are contained in all phosphazene compounds. A cyclic phosphazene compound containing at least% by weight is preferred. Further, at least one of the substituents X is an aryloxy group represented by the general formula (2) (wherein R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are a hydrogen atom and a carbon atom having 1 to 5 carbon atoms. It represents an alkyl group or an alkoxy group, or a phenyl group, and all of R _{1 to} R ₅ are not hydrogen atoms), and all the substituents X may be aryloxy groups. Further, the aryloxy groups of the substituent X may be the same or different in the molecule.
[0012]
Although the substituents R ₁ , R ₂ , R ₃ , R ₄ and R ₅ on the aryloxy group are not particularly limited, examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group. Group, a tert-butyl group, an n-amyl group, an isoamyl group, a methoxy group, a linear or branched alkyl group or an alkoxy group such as an ethoxy group or a phenyl group, and these phosphazene compounds may be used alone. It may be used as a mixture of two or more kinds, or as a mixture of a chain phosphazene compound and a cyclic phosphazene compound. Phosphazene compounds used in the present invention, at least one alkyl group of the substituents R ₁ to R ₅ on the aryloxy group of the general formula (2) may be any alkoxy group or a phenyl group, R ₁ to R All ₅ may be an alkyl group, an alkoxy group or a phenyl group. Considering the production cost, the substituent X represented by the general formula (2) is a crezooxy group in which any of R ₁ , R ₂ or R ₃ is a methyl group, and two of R _{1 to} R ₅ are methyl groups. The xylenoxy group of is preferred.
[0013]
Moreover, the 6-membered phosphazene with n = 3 may be used alone or as a mixture with a multi-membered phosphazene with n = 4 or more. References and synthesis examples for obtaining these phosphazene compounds are disclosed (for example, see Patent Documents 11 to 14).
In the present invention, the ratio between the resin and the phosphazene compound is not particularly limited, but may be within a range that does not impair the effects of the present invention. Specifically, the addition amount of the phosphazene compound is preferably in the range of 1 to 35% by weight, and more preferably in the range of 3 to 30% by weight. If the amount of the phosphazene compound is less than 1% by weight, sufficient flame retardancy cannot be obtained, which is not preferable. On the other hand, when the flame retardancy cannot be imparted unless the amount of the phosphazene compound is 35% by weight or more, the ratio of the flame retardant composition in the resin composition becomes too large, and the heat resistance of the resin composition is greatly reduced. This is not preferred because it adversely affects the physical properties of the composition.
[0014]
In the present invention, conventionally known non-halogen and non-antimony flame retardants can be used in addition to the phosphazene compound as the component (b) as long as the effects of the present invention can be achieved. For example, phosphate esters such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xyenyl diphenyl phosphate, dixylenyl phenyl phosphate, hydroxynon bisphenol, resorcinol bisphosphate, bisphenol A bisphosphate, etc. And metal hydroxides such as magnesium hydroxide, aluminum hydroxide and calcium aluminate, and nitrogen-containing compounds such as triazine compounds, melamine, melamine cyanurate, melamine resins and guanidine compounds.
[0015]
In the resin composition of the present invention, when it is necessary to further improve the rigidity and dimensional stability of the resin composition, an inorganic filler can be added. The filler type can be arbitrarily selected according to the purpose, but glass fiber, glass flake, mica, talc, silica, zircon, alumina, gypsum, quartz, magnesite, kaolin, silicon carbide, calcium carbonate, iron powder, copper powder, etc. are generally used. It is commonly used.
To the resin composition of the present invention, in order to impart still other properties, other additives such as a plasticizer, an antioxidant, and a stabilizer such as an ultraviolet absorber, curing are not impaired so long as the effects of the present invention are not impaired. Agents, effect promoters, antistatic agents, stress relievers, release agents, flow regulators, dyes, sensitizers, coloring pigments, rubbery polymers and the like can be added. Further, conventionally known various flame retardants and flame retardant assistants, for example, alkali metal hydroxides or alkaline earth metal hydroxides such as magnesium hydroxide and aluminum hydroxide containing water of crystallization, zinc borate compounds, Addition of a zinc stannate compound and further an inorganic silicon compound such as silica, kaolin clay, and talc can further improve flame retardancy.
[0016]
The method for producing the resin composition of the present invention is not particularly limited as long as the effects of the present invention can be achieved. For example, kneading can be performed using a kneading machine such as an extruder, a heating roll, a kneader, and a Banbury mixer. Among them, kneading with an extruder is preferable in terms of productivity. The kneading temperature may be in accordance with the preferred processing temperature of the base resin, and is in the range of 200 to 360 ° C, preferably in the range of 240 to 320 ° C.
[0017]
In the case of a thermosetting resin, the components for producing the resin composition are mixed using a solvent that can be uniformly mixed, or mixed without a solvent, cast into a mold, cured, and then cooled. Then, a method of obtaining a molded product by taking out from the mold may be used. Further, a method of kneading and manufacturing using a kneading machine such as a heating roll, a kneader, a Banbury mixer, an extruder, cooling, pulverizing, and further performing molding by transfer molding, injection molding, compression molding, or the like may be mentioned as an example. it can. The curing method varies depending on the curing agent used, but is not particularly limited. Examples include thermal curing, light curing, curing by pressure, curing by moisture, and the like, but are not limited as long as the curing method can achieve the effects of the present invention. The order of mixing the components is not particularly limited as long as the effects of the present invention can be achieved. As a method for producing the resin composition, a preferable method can be used depending on the suitability of each resin.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to the following Examples. “%” In the following Examples and Comparative Examples means “% by weight”.
The components used in the examples and comparative examples are as follows.
(A) Resin PPE: polyphenylene ether Poly-2,6-dimethyl-1,4-phenylene ether having an ηsp / c of 0.52 measured with a chloroform solution at 30 ° C.
Rubber-reinforced polystyrene (HIPS): rubber-reinforced polystyrene having a rubber content of 9%, ηsp / c of matrix polystyrene measured at 30 ° C. and a toluene solution of 0.70, and a volume average rubber particle diameter of 1.5 μm.
GP685: polystyrene 685 (manufactured by A & M Styrene Co., Ltd.)
(B) Phosphazene:
FR1: hexa (o-crezoxy) phosphazene represented by the formula (4), in which no peak other than hexa (o-crezooxy) phosphazene represented by the formula (4) is observed in ³¹ PNMR.
[0019]
Embedded image

[0020]
FR2: a cyclic phosphazene trimer represented by the formula (5), in which a peak other than the phosphazene represented by the formula (5) is not observed in ³¹ P NMR.
[0021]
Embedded image

[0022]
FR3: a cyclic phosphazene trimer represented by the formula (6), in which a peak other than the phosphazene represented by the formula (6) is not observed in ³¹ P NMR.
[0023]
Embedded image

[0024]
FR4: a cyclic phosphazene trimer represented by the formula (7), in which a peak other than the phosphazene represented by the formula (7) is not observed in ³¹ P NMR.
[0025]
Embedded image

[0026]
FR5: a cyclic hexaphenoxyphosphazene trimer represented by the formula (8), in which a peak other than the cyclic hexaphenoxyphosphazene represented by the formula (8) is not observed in ³¹ P NMR.
[0027]
Embedded image

[0028]
FR6: triphenyl phosphate The physical properties of the resin compositions of Examples and Comparative Examples were evaluated by the following methods.
(1) Flame retardancy: Based on the UL-94 vertical combustion test, a molded test piece having a length of 128 mm, a width of 12.8 mm, and a thickness of 1.6 mm was used. V-0, V-1, V-2 and four levels out of the standard were classified according to the presence or absence of cotton ignition by the dripping material at the time. The evaluation criteria are shown below, and the shorter the quenching time, the better the flame retardancy.
[0029]
V-0: All of the following conditions are satisfied.
(A) The total of the flame extinction time after the 10 times of flame contact, 5 test pieces twice each, within 50 seconds.
(B) Five test pieces were subjected to flame contact twice each, and the flame extinction time after each flame contact was within 5 seconds.
(C) There is no ignition of absorbent cotton 300 mm below by the dripping material in all the test pieces.
(D) For all test pieces, glowing after the second flame contact was within 30 seconds.
(E) For all test pieces, do not frame until the clamp.
[0030]
V-1: All the following conditions are satisfied.
(A) The total flame extinction time after the flame contact of 10 times, 5 times each for 2 test pieces, is 250 seconds or less.
(B) Five test pieces were subjected to flame contact twice each, and the extinction time after each flame contact was within 30 seconds.
(C) There is no ignition of absorbent cotton 300 mm below by the dripping material in all the test pieces.
(D) For all test pieces, glowing after the second flame contact was within 60 seconds.
(E) For all test pieces, do not frame until the clamp.
[0031]
V-2: All the following conditions are satisfied.
(A) The total flame extinction time after the flame contact of 10 times, 5 times each for 2 test pieces, is 250 seconds or less.
(B) Five test pieces were subjected to flame contact twice each, and the extinction time after each flame contact was within 30 seconds.
(C) At least one of the five test pieces ignited the absorbent cotton 300 mm below by the dripping material.
(D) For all test pieces, glowing after the second flame contact was within 60 seconds.
(E) For all test pieces, do not frame until the clamp.
[0032]
(2) Dielectric Characteristics The relative permittivity and the dielectric loss tangent were measured at a frequency of 1 GHz, 5 GHz, and 10 GHz by a triplate method using a 150 × 150 mm molded piece having a thickness of about 2 mm.
[0033]
Examples 1-4, Comparative Examples 1-2
Each component was mixed at the ratio shown in Table 1, supplied to a twin-screw extruder with a screw diameter of 25 mm and the maximum temperature of the heating cylinder was set to 300 ° C, melt-kneaded at a screw rotation speed of 300 rpm, and cooled and cut the strand. Thus, resin composition pellets were obtained.
Next, physical properties test pieces were formed from the obtained resin composition pellets at 240 to 290 ° C. by injection molding, and physical properties tests were performed by the above-described test methods.
[0034]
[Table 1]

[0035]
【The invention's effect】
The present invention provides a resin composition which does not contain a halogen compound, has excellent electrical properties, is environmentally preferable, and has high flame retardancy.

Claims (16)

(A) resin and (b) the following formula (1)

(Wherein n is an integer of 1 to 8), wherein at least one of X in the formula is the following general formula (2)

(Wherein R ₁ , R ₂ , R ₃ , R ₄ and R ₅ represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group or a phenyl group; _{1 to} R ₅ are not all hydrogen atoms at the same time, and the others are phenoxy groups.) And / or the following formula (3)

(Wherein m is an integer of 1 to 20), wherein X in the formula (3) is at least one of the following general formula (2)

(Wherein R ₁ , R ₂ , R ₃ , R ₄ and R ₅ represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group or a phenyl group; _{1 to} R ₅ are not all hydrogen atoms at the same time, and the others are phenoxy groups), and the total amount of the components (a) and (b) is 100% by weight, (b) A flame-retardant resin composition used in a high frequency band of 1 gigahertz (GHz) or more, comprising 1 to 35% by weight of a phosphazene compound as a component. The flame-retardant resin composition according to claim 1, comprising 3 to 30% by weight of the phosphazene compound (b). 3. The flame-retardant resin composition according to claim 1, wherein the phosphazene compound as the component (b) is a cyclic phosphazene compound represented by the general formula (1). The flame-retardant resin composition according to claim 1, wherein the phosphazene compound as the component (b) is a chain phosphazene compound represented by the general formula (3). The flame-retardant resin composition according to any one of claims 1, 2, 3, and 4, wherein the resin is a thermoplastic resin. The flame-retardant resin composition according to claim 1, wherein the resin is a thermosetting resin. The flame-retardant resin composition according to claim 1, wherein the resin is a combination of a thermoplastic resin and a thermosetting resin. 4. The resin according to claim 1, wherein the resin is at least one resin selected from a polyphenylene ether resin, a styrene resin, an aromatic polycarbonate resin, a polyimide resin, a polyphenylene sulfide, an aromatic epoxy resin, and a phenol resin. Or the flame-retardant resin composition of any one of 4. 5. The flame-retardant resin composition according to claim 1, wherein the resin comprises a polyphenylene ether resin or a polyphenylene ether resin and a styrene resin, or a polyphenylene ether resin and an epoxy resin. 5. The flame-retardant resin composition according to claim 1, wherein the phosphazene compound contains at least 80% by weight of a phosphazene trimer and a tetramer. The flame-retardant resin composition according to any one of claims 1, 2, 3 and 4, wherein all the substituents X of the phosphazene compound are aryloxyphosphazenes, which are aryl groups represented by the formula (2). object. 5. The method according to claim 1, wherein at least one of the substituents X of the phosphazene compound is a phenoxy group, and the remaining substituent is an aryloxyphosphazene, which is an aryl group represented by the formula (2). The flame-retardant resin composition according to any one of the above. The flame-retardant resin composition according to any one of claims 1, 2, 3, and 4, wherein all of the substituents X of the phosphazene compound are crezooxy groups. The flame-retardant resin composition according to claim 1, wherein at least one of the substituents X of the phosphazene compound is a phenoxy group, and the remaining substituent is a crezooxy group. . The flame-retardant resin composition according to any one of claims 1, 2, 3 and 4, wherein all of the substituents X of the phosphazene compound are xylenoxy groups. The flame-retardant resin composition according to claim 1, wherein at least one of the substituents X of the phosphazene compound is a phenoxy group, and the remaining substituent is a xylenoxy group. .