阅读说明：本技术 阻燃性树脂组合物、其制造方法以及氢化石油树脂 (Flame-retardant resin composition, process for producing the same, and hydrogenated petroleum resin ) 是由 河崎广 内泽将太郎 渡边一玄 于 2020-04-08 设计创作，主要内容包括：一种阻燃性树脂组合物,其含有：属于不饱和烃的聚合物的氢化物的氢化石油树脂、聚烯烃、及无机填充材料,所述不饱和烃含有选自由具有五元环的脂环式化合物及芳香族烃化合物组成的组中的至少1种。(A flame-retardant resin composition comprising: the hydrogenated petroleum resin is a hydrogenated petroleum resin of a polymer of an unsaturated hydrocarbon containing at least 1 selected from the group consisting of an alicyclic compound having a five-membered ring and an aromatic hydrocarbon compound, a polyolefin, and an inorganic filler.)

1. A flame-retardant resin composition comprising: the hydrogenated petroleum resin is a hydrogenated petroleum resin of a polymer of an unsaturated hydrocarbon containing at least 1 selected from the group consisting of an alicyclic compound having a five-membered ring and an aromatic hydrocarbon compound, a polyolefin, and an inorganic filler.

2. The flame-retardant resin composition according to claim 1, wherein the alicyclic compound comprises a DCPD-based compound having a dicyclopentadiene skeleton.

3. The flame-retardant resin composition according to claim 1 or 2, wherein the aromatic hydrocarbon compound contains at least 1 selected from the group consisting of an indene compound having an indene skeleton and a styrene compound having a styrene skeleton.

4. The flame-retardant resin composition according to any one of claims 1 to 3, wherein the polyolefin comprises at least 1 selected from the group consisting of an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, polyethylene, and polypropylene.

5. A method for producing a flame-retardant resin composition, which comprises a step of bringing into contact a hydrogenated petroleum resin which is a hydrogenated product of a polymer of an unsaturated hydrocarbon containing at least 1 selected from the group consisting of an alicyclic compound and an aromatic hydrocarbon compound having a five-membered ring, a polyolefin, and an inorganic filler.

6. A hydrogenated petroleum resin for flame-retardant resin compositions, which is a hydrogenated product of a polymer containing at least 1 unsaturated hydrocarbon selected from the group consisting of alicyclic compounds and aromatic hydrocarbon compounds having five-membered rings.

Technical Field

The present invention relates to a flame-retardant resin composition, a method for producing the same, and a hydrogenated petroleum resin.

Background

Conventionally, flame retardant resins have been widely used for members requiring flame retardancy, such as electric wires (communication cables, wiring in equipment, power lines, optical fiber lines, etc.), electric devices (lightning protection covers, underground pipes, etc.), automobiles (inner sheets, electric wire protection pipes, etc.), building materials (maintenance sheets, duct hoses, electric wire protection pipes, chairs for stadiums, etc.), home appliances (housings, etc.). For example, patent document 1 discloses a flame-retardant resin composition containing a base resin containing a specific resin, calcium carbonate particles, a silicone compound, and a fatty acid-containing compound, as a flame-retardant resin composition used for an insulating layer or a sheath (outer covering) constituting a cable.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-155931

Disclosure of Invention

Problems to be solved by the invention

When the flame-retardant resin composition is used as a material for a cable sheath (an insulator for covering the periphery of a conductor such as an electric wire, a sheath (outer covering), or the like), it is preferable to maintain strength against stress (tensile strength) and have good strength against strain. As a flame-retardant resin composition having such characteristics, a polyvinyl chloride resin (PVC) has been widely used, but PVC has a problem of generating toxic gas when burned.

Accordingly, an object of the present invention is to provide a flame-retardant resin composition which can maintain strength against strain and achieve good strength against strain. Another object of the present invention is to provide a method for producing the flame-retardant resin composition, and a hydrogenated petroleum resin used for the flame-retardant resin composition.

Means for solving the problems

The present inventors have solved the above problems by designing a flame-retardant resin composition to have a specific composition. That is, the present invention provides a flame-retardant resin composition comprising: the hydrogenated petroleum resin is a hydrogenated petroleum resin of a polymer of an unsaturated hydrocarbon containing at least 1 selected from the group consisting of an alicyclic compound having a five-membered ring and an aromatic hydrocarbon compound, a polyolefin, and an inorganic filler.

The alicyclic compound may include a DCPD (Dicyclopentadiene) based compound having a Dicyclopentadiene skeleton.

The aromatic hydrocarbon compound may include at least 1 selected from the group consisting of an indene-based compound having an indene skeleton and a styrene-based compound having a styrene skeleton.

The polyolefin may include at least 1 selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyethylene, and polypropylene.

The present invention also provides a method for producing a flame-retardant resin composition, comprising a step of bringing into contact a hydrogenated petroleum resin which is a hydrogenated product of a polymer of an unsaturated hydrocarbon containing at least 1 selected from the group consisting of an alicyclic compound having a five-membered ring and an aromatic hydrocarbon compound, a polyolefin, and an inorganic filler.

Further, the present invention provides a hydrogenated petroleum resin for a flame-retardant resin composition, which is a hydrogenated product of a polymer containing at least 1 unsaturated hydrocarbon selected from the group consisting of an alicyclic compound and an aromatic hydrocarbon compound having a five-membered ring.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a flame retardant resin composition is provided which can maintain strength against strain and achieve good strength against strain. The present invention also provides a method for producing the flame-retardant resin composition, and a hydrogenated petroleum resin used for the flame-retardant resin composition. In addition, the flame retardant resin composition can replace PVC.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail.

The flame-retardant resin composition of the present embodiment contains a hydrogenated petroleum resin which is a hydrogenated product of an unsaturated hydrocarbon polymer, a polyolefin, and an inorganic filler.

Hydrogenated petroleum resins are hydrogenated products of polymers of unsaturated hydrocarbons (hereinafter, also referred to as "petroleum resins") which have carbon-carbon double bonds as polymerizable groups and are capable of mutual polymerization.

The unsaturated hydrocarbon contains at least 1 selected from the group consisting of alicyclic compounds and aromatic hydrocarbon compounds having five-membered rings.

The unsaturated hydrocarbon may be a component contained in a fraction collected from petroleum-derived raw oil by thermal decomposition or the like, or may be a component mainly contained in petroleum-derived C5 or C9 fractions.

In the present embodiment, the alicyclic compound is a compound having a five-membered ring and no aromatic ring. Examples of the alicyclic compound include: a DCPD-based compound having a dicyclopentadiene skeleton, a CPD (Cyclopentadiene) -based compound having a Cyclopentadiene skeleton (a C5-based compound), and the like. Here, the dicyclopentadiene skeleton means a carbon skeleton having dicyclopentadiene. The cyclopentadiene skeleton means a carbon skeleton having cyclopentadiene.

The unsaturated hydrocarbon preferably contains a DCPD-based compound as the alicyclic compound. Examples of the DCPD-based compound include: dicyclopentadiene, methyldicyclopentadiene, and the like.

Examples of the CPD-based compound include: cyclopentadiene, methylcyclopentadiene, and the like.

The content of the DCPD-based compound in the alicyclic compound may be, for example, 50 mass% or more, preferably 60 mass% or more, more preferably 70 mass% or more, or may be 100 mass%.

The content of the alicyclic compound in the unsaturated hydrocarbon may be, for example, 30 mass% or more, preferably 35 mass% or more, and more preferably 40 mass% or more, based on the total amount of the unsaturated hydrocarbon. This tends to facilitate the polymerization reaction and to easily obtain the desired polymer. The content of the alicyclic compound in the unsaturated hydrocarbon may be, for example, 85 mass% or less, preferably 80 mass% or less, and more preferably 70 mass% or less, based on the total amount of the unsaturated hydrocarbon. This tends to facilitate the production of a hydrogenated petroleum resin having high compatibility with the resin component.

The aromatic hydrocarbon compound may be, for example, a C9-based compound mainly contained in a petroleum-derived C9 fraction, and specifically, there may be mentioned: having indene (C)₉H₈) Indene compounds having a skeleton, styrene compounds having a styrene skeleton, and the like. Examples of the indene compound include: indene, methyl indene, and the like. Examples of the styrenic compound include: styrene, methyl styrene, and the like.

The content of the aromatic hydrocarbon compound in the unsaturated hydrocarbon may be, for example, 10 mass% or more, 20 mass% or more, or 30 mass% or more based on the total amount of the unsaturated hydrocarbon. The content of the aromatic hydrocarbon compound may be, for example, 60 mass% or less, 50 mass% or less, or 40 mass% or less based on the total amount of the unsaturated hydrocarbons.

When the unsaturated hydrocarbon further contains the alicyclic compound and the aromatic hydrocarbon compound, the content C of the aromatic hydrocarbon compound₁With the content C of the alicyclic compound₂Ratio of (C)₁/C₂(mass ratio) is preferably 0.25 or more, more preferably 0.43 or more. This tends to facilitate the production of a hydrogenated petroleum resin having high compatibility with the resin component. In addition, the ratio C₁/C₂Preferably 1.38 or less, more preferably 1.27 or less. This tends to facilitate the polymerization reaction and to easily obtain the target polymer.

In addition to the alicyclic compound and the aromatic hydrocarbon compound, for example, an aliphatic compound having no cyclic structure, an alicyclic compound having no five-membered ring, a heterocyclic compound having a heterocycle, or the like may be contained as the unsaturated hydrocarbon. Examples of the aliphatic compound include: pentadiene, isoprene, and the like. Examples of the heterocyclic compound include benzofuran and the like. The content of these unsaturated hydrocarbons may be 5% by mass or less, 1% by mass or less, or 0% by mass based on the total amount of unsaturated hydrocarbons.

The petroleum resin may mean a polymer having a structural unit derived from at least 1 compound selected from the group consisting of the above alicyclic compound and the above aromatic hydrocarbon compound. The content of the structural unit in the petroleum resin corresponds to the content of the alicyclic compound and/or the aromatic hydrocarbon compound in the unsaturated hydrocarbon.

Petroleum resins can be obtained by polymerizing unsaturated hydrocarbons. The method for polymerizing the unsaturated hydrocarbon is not particularly limited, and may be appropriately selected from known polymerization methods.

In a preferred embodiment, the petroleum resin is obtained by thermally polymerizing an unsaturated hydrocarbon. The method of thermal polymerization is not particularly limited, and may be carried out by heating a raw material composition containing an unsaturated hydrocarbon to a predetermined reaction temperature, for example.

The reaction temperature of the thermal polymerization is not particularly limited, and may be, for example, 250 ℃ or higher, preferably 260 ℃ or higher, and more preferably 270 ℃ or higher. The reaction temperature of the thermal polymerization may be, for example, 300 ℃ or lower, preferably 290 ℃ or lower, and more preferably 280 ℃ or lower.

The reaction time of the thermal polymerization (the time for maintaining the reaction system at the reaction temperature) is not particularly limited, and may be, for example, 30 to 180 minutes, and preferably 60 to 120 minutes.

The raw material composition used for the thermal polymerization may further contain a component other than the unsaturated hydrocarbon. For example, there are cases where petroleum-derived fractions (C5 fractions, C9 fractions, and the like) further contain non-polymerizable hydrocarbons that do not have polymerizable groups and do not participate in thermal polymerization. The raw material composition used for the thermal polymerization may further contain such a non-polymerizable hydrocarbon. Examples of the non-polymerizable hydrocarbon include: saturated hydrocarbons (alkanes, cycloalkanes, etc.), aromatic hydrocarbons (benzene, toluene, etc.), and the like.

When the raw material compound contains components other than the unsaturated hydrocarbon, the unsaturated hydrocarbon can be removed, for example, by thermally polymerizing the unsaturated hydrocarbon and then removing the light components (distillation).

Hydrogenated petroleum resins are the hydrides of petroleum resins. The hydrogenated petroleum resin may be a partial hydride of a petroleum resin or a complete hydride of a petroleum resin, preferably a partial hydride. That is, the hydrogenated petroleum resin may be one obtained by hydrogenating a part or all of the reducing sites such as unsaturated bonds contained in the petroleum resin.

The softening point of the hydrogenated petroleum resin is not particularly limited, and may be, for example, 80 ℃ or higher, 90 ℃ or higher, or 100 ℃ or higher. If the softening point of the hydrogenated petroleum resin is within the above range, the strength characteristics of the flame-retardant resin can be further improved. The upper limit of the softening point of the hydrogenated petroleum resin is not particularly limited, and may be, for example, 150 ℃ or lower, 130 ℃ or lower, or 120 ℃ or lower. When the softening point of the hydrogenated petroleum resin is within the above numerical range, the processability tends to be improved. In the present specification, the softening point of the hydrogenated petroleum resin means a value measured by a method according to ASTM D6090 using DP70 from Mettler Toledo.

The weight average molecular weight of the hydrogenated petroleum resin is not particularly limited, and may be, for example, 4000 or less, 2000 or less, or 1000 or less. The lower limit of the weight average molecular weight of the hydrogenated petroleum resin is not particularly limited, and may be, for example, 300 or more, or 350 or more. In the present specification, the weight average molecular weight of the hydrogenated petroleum resin means a value obtained by measuring the weight average molecular weight by GPC (Gel Permeation Chromatography) and converting the weight average molecular weight into standard polystyrene.

Hydrogenated petroleum resins can be obtained by hydrogenating polymers of unsaturated hydrocarbons (petroleum resins). The method for obtaining the hydride by hydrogenating the petroleum resin is not particularly limited, and a known method can be used. For example, the hydrogenation can be carried out by: the petroleum resin is passed through a reactor packed with a hydrogenation catalyst, and the hydrogenation catalyst is brought into contact with the petroleum resin in the presence of hydrogen. The hydrogenation of the petroleum resin may be carried out in a solvent or without the use of a solvent.

The hydrogenation catalyst is not particularly limited, and may be, for example, a nickel-based catalyst, a palladium-based catalyst, a platinum-based catalyst, or the like.

The conditions of the hydrogenation reaction may be appropriately changed depending on the kind of the petroleum resin or the desired physical properties of the hydrogenated petroleum resin. The hydrogen pressure in the hydrogenation reaction may be, for example, 5MPa or more, or may be 10MPa or more. The hydrogen pressure in the hydrogenation reaction may be, for example, 30MPa or less, or 20MPa or less. The reaction temperature in the hydrogenation reaction may be, for example, 200 ℃ or higher, or 230 ℃ or higher. The reaction temperature in the hydrogenation reaction may be, for example, 310 ℃ or lower, or 300 ℃ or lower.

The content of the hydrogenated petroleum resin may be 1 mass% or more, 2 mass% or more, or 5 mass% or more based on the total amount of the flame-retardant resin composition. The content of the hydrogenated petroleum resin may be 25% by mass or less, or 20% by mass or less, or 15% by mass or less, based on the total amount of the flame-retardant resin composition.

The flame-retardant resin composition of the present embodiment contains polyolefin as a resin. The polyolefin is not particularly limited, and is preferably a thermoplastic resin, for example. Examples of such polyolefins include: ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), polyethylene, polypropylene, and the like, and among them, at least 1 selected from the group consisting of EVA and EEA is preferable.

For example, when EVA is used as the polyolefin, the content of vinyl acetate in EVA may be, for example, 30 to 50 mass%.

The content of the polyolefin may be 5% by mass or more, may be 8% by mass or more, and may be 10% by mass or more based on the total amount of the flame-retardant resin composition. The content of the polyolefin may be 35% by mass or less, 30% by mass or less, or 25% by mass or less based on the total amount of the flame-retardant resin composition.

The inorganic filler used in the flame-retardant resin composition of the present embodiment is not particularly limited, and for example, the following may be used: aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and the like. These inorganic fillers may be used alone in 1 kind or in combination of 2 or more kinds. The shape of the inorganic filler is not particularly limited, and may be any of powder, flake, fiber, and the like.

The flame-retardant resin composition of the present embodiment may contain other additives than the above-described components within a range not significantly impairing the effects of the present invention. The other additives are not particularly limited as long as they are usually added to the flame-retardant resin composition, and examples thereof include antioxidants, lubricants, processing stabilizers, colorants, foaming agents, reinforcing agents, and the like. The content of these other additives may be, for example, 5% by mass or less, or 1% by mass or less, based on the total amount of the flame-retardant resin composition.

The flame-retardant resin composition of the present embodiment can be produced through a step of mixing the hydrogenated petroleum resin, the polyolefin, the inorganic filler, and other additives as needed. The step may be, for example, a step of adding the hydrogenated petroleum resin to a mixture containing a polyolefin, an inorganic filler, and, if necessary, another filler. That is, the above-mentioned hydrogenated petroleum resin may also be referred to as a hydrogenated petroleum resin for a flame-retardant resin composition added to a flame-retardant resin.

The density of the flame-retardant resin composition is not particularly limited, and may be, for example, 1.0g/cm³Above, 1.2g/cm³Above, or 1.4g/cm³Above, and may be 2.0g/cm³1.8g/cm below³Below, or 1.6g/cm³The following. In the present specification, the density is a value measured at 23 ℃ according to method a (underwater substitution method) of JIS K7112.

The flame-retardant resin composition of the present embodiment can achieve not only excellent strain at the breaking point but also excellent processability in processing a molded article. The melt mass flow rate (MFR (21.6kg)) of the flame-retardant resin composition as an evaluation index of processability under a load of 21.6kg is, for example, 50g/10 min or more, 60g/10 min or more, or 70g/10 min or more. The upper limit of MFR (21.6kg) is, for example, 200g/10 min or less, 180g/10 min or less, or 160g/10 min or less. The flame-retardant resin composition has a melt mass flow rate (MFR (2.16kg)) under a load of 2.16kg of, for example, 0.01g/10 min or more, 0.05g/10 min or more, and 0.1g/10 min or more. The upper limit of MFR (2.16kg) is, for example, 1g/10 min or less, 0.95g/10 min or less, or 0.9g/10 min or less. In the present specification, MFR is a value measured under the conditions of a temperature of 190 ℃ and a load of 2.16kg or 21.6kg according to method A (mass measurement) of JIS K7210-1.

The flame-retardant resin composition obtained as described above is melted and kneaded in a general-purpose kneading device such as an extruder, whereby a flame-retardant resin molded article having a desired shape can be produced. The flame-retardant resin molded article can be processed into various forms such as a sheet, a tape, and a rod depending on the application. For example, when used as a cable sheath for covering the periphery of a conductor such as an electric wire, the flame-retardant resin composition can be obtained by processing the flame-retardant resin composition by wire coating molding, tube molding, or the like.

The flame-retardant resin molded article obtained from the flame-retardant resin composition of the present embodiment has good strength against strain, and therefore can be used favorably as the cable sheath as described above. The strength against strain can be evaluated by determining the value of the strain at the breaking point. The flame-retardant resin molded article may have flame retardancy which is generally required as a flame-retardant resin, and may also have other strength characteristics such as yield stress and breaking point stress which are required as a cable sheath.

Examples

The present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples.

[ production of Petroleum resin ]

(example 1)

< Synthesis of Polymer of unsaturated Hydrocarbon >

The components shown in table 1 were mixed at the mass ratios shown in table 1 to obtain mixed solutions. Then, the obtained mixed solution was charged into a thermal polymerization apparatus (manufactured by Toyo Koatsu corporation). Then, the mixed solution was heated to 276 ℃ at a heating rate of 5 ℃/min and maintained for 120 minutes. Thereafter, cooling water was flowed through the solution to quench the solution, thereby obtaining a hot polymerization resin solution. The obtained hot polymerization resin solution is subjected to light component removal (distillation) to remove unreacted materials and components having a low degree of polymerization, thereby obtaining a polymer.

< hydrogenation of polymers of unsaturated hydrocarbons >

The obtained unsaturated hydrocarbon polymer was dissolved in kerosene with the concentration adjusted to 30 mass%. The obtained solution was charged into a hydrogenation reactor packed with a nickel-based catalyst, while passing hydrogen gas therethrough, and hydrogenation of the unsaturated hydrocarbon polymer was carried out under conditions of a pressure of 18MPa and a temperature of 280 ℃ for 1 hour to obtain a solution containing a hydrogenated product of the unsaturated hydrocarbon polymer. The obtained solution containing the hydrogenated product of the unsaturated hydrocarbon polymer is subjected to light component removal (distillation) to remove kerosene in the solution, thereby obtaining a hydrogenated petroleum resin (petroleum resin a).

(example 2)

A hydrogenated petroleum resin (petroleum resin B) was obtained in the same manner as in example 1, except that the components of the mixed solution were changed to the compositions shown in table 1 and the maximum temperature at the time of polymerization was 268 ℃.

(example 3)

A hydrogenated petroleum resin (petroleum resin C) was obtained in the same manner as in example 1, except that the components of the mixed solution were changed to the compositions shown in table 1 and the maximum temperature at the time of polymerization was 268 ℃.

Comparative example 1

A solution having a composition shown in table 1 was prepared, and this solution and a lewis acid catalyst were introduced into a polymerization apparatus set to 30 ℃, to obtain a catalyst polymerization resin solution. The obtained catalytic polymerization resin solution was subjected to light component removal (distillation) to remove unreacted materials and components having a low degree of polymerization, thereby obtaining an unsaturated hydrocarbon polymer (petroleum resin D).

Comparative example 2

A solution having a composition shown in table 1 was prepared, and this solution and a lewis acid catalyst were introduced into a polymerization apparatus set to 30 ℃, to obtain a catalyst polymerization resin solution. The obtained catalytic polymerization resin solution was subjected to light component removal (distillation) to remove unreacted materials and components having a low degree of polymerization, thereby obtaining an unsaturated hydrocarbon polymer (petroleum resin E).

[ measurement of resin softening Point of Petroleum resin ]

The softening points of the samples of petroleum resins A to E obtained in the above were measured by a method in accordance with ASTM D6090 using DP70 from Mettler Toledo. The results are shown in Table 1.

[ Table 1]

[ preparation of flame-retardant resin composition ]

The petroleum resins a to E obtained in the above, the ethylene-vinyl acetate copolymer, the inorganic filler and the antioxidant were kneaded in the composition (unit: mass%) shown in table 2 below to obtain a flame-retardant resin composition. In the kneading, a pressure kneader (manufactured by Toyo Seiki Seisaku-Sho Ltd.) and a roller mill (manufactured by KNEADER MACHINERY Co.) were used, and the kneading conditions were 180 ℃ at the start temperature, 50rpm at the rotation speed, and 15 minutes at the kneading time. The details of the components in table 2 are as follows.

Ethylene-vinyl acetate copolymer (EVA): NUC-3195, NUC

Inorganic filler material: magnesium hydroxide, Kisuma 5A, from Kyoho chemical industries

Antioxidant: irganox1010, manufactured by BASF corporation

[ evaluation of Strain at Break Point ]

The flame-retardant resin compositions obtained in examples 4 to 8 and comparative examples 3 to 4 were heat-molded at a heating temperature of 180 ℃ for 10 minutes to obtain flame-retardant resin moldings. The obtained flame-retardant resin molded article was punched out into a dumbbell-shaped No. 3 having a thickness of 1mm, a width of 5mm and a distance between gauge lines of 20mm to obtain a test piece. Using the obtained test piece, a tensile test was conducted at a tensile speed of 200 mm/min with reference to JIS K6251, and the strain at break point (elongation of the resin before break) was measured. The results are shown in Table 2. In table 2, it can be said that the larger the value of the strain at the breaking point, the larger the elongation before breaking.

[ Table 2]

[ evaluation of other Properties of flame-retardant resin composition ]

The flame-retardant resin compositions obtained in examples 4 to 8 were evaluated for the following physical properties other than the above strain at break point. The evaluation results are shown in table 3.

< tensile Property (yield stress, fracture stress) >

The flame-retardant resin compositions obtained in examples 4 to 8 were heat-molded at a heating temperature of 180 ℃ for 10 minutes to obtain flame-retardant resin moldings. The obtained flame-retardant resin molded article was punched out into a dumbbell shape No. 3 having a thickness of 1mm, a width of 5mm and a distance between gauge lines of 20mm, and the yield stress and the breaking point stress were measured at a tensile rate of 200 mm/min with respect to the obtained test piece by the method described in JIS K6251. The results are shown in Table 3. In table 3, it can be said that the larger the values of yield stress and breaking point stress, the better the tensile properties.

< processability (melt flow Rate: MFR) >

The MFR of the flame-retardant resin compositions obtained in examples 4 to 8 was measured under the conditions of a temperature of 190 ℃ and a load of 2.16kg or 21.6kg in accordance with method A (mass measurement) of JIS K7210-1. The measurement results are shown in table 3. The MFR values of the degree that no practical problem in processability was observed in any of the examples. In table 3, it can be said that the larger the value of MFR under each load, the better the processability.

< flame retardancy (critical oxygen index) >

The flame-retardant resin compositions obtained in examples 4 to 8 were heat-molded at a heating temperature of 180 ℃ for 10 minutes to obtain flame-retardant resin moldings. The obtained flame-retardant resin molded article was cut into a form IV having a thickness of 3mm, a width of 6.5mm and a length of 128mm, and the obtained test piece was subjected to the method described in JIS K7201-2 in the following procedure C, ignition method: the measurement was performed by the B method (propagation ignition). The results are shown in Table 3. Any of the examples shows a critical oxygen index to the extent that there is no practical problem in flame retardancy. In table 3, it can be said that the larger the value of the critical oxygen index is, the more excellent the flame retardancy is.

< Density >

The flame-retardant resin compositions obtained in examples 4 to 8 were measured for density at 23 ℃ according to method A (underwater substitution method) of JIS K7112. The results are shown in Table 3.

[ Table 3]