JP6353948B1 - Thermoplastic resin composition - Google Patents

Abstract

A thermoplastic resin composition having excellent ignition resistance and flame retardancy is provided. A cracking furnace temperature at which the heat release rate measured based on ASTM D7309 Method A using a microscale combustion calorimeter and containing a thermoplastic resin reaches 20 W / g is 350 ° C. or higher, and a cracking furnace temperature of 200 to A thermoplastic resin composition having a total calorific value at 600 ° C. of 38.5 kJ / g or less is used. [Selection figure] None

Description

  The present invention relates to a thermoplastic resin composition excellent in ignition resistance and flame retardancy.

  Thermoplastic resins make use of their excellent moldability and are used in many products such as food packaging containers, miscellaneous goods, building materials, automobile materials, OA equipment, electronic components, and home appliance housings.

  On the other hand, the thermoplastic resin is flammable, and there was concern about the safety of the product. Therefore, in order to eliminate this flammability, conventionally, flame retardant studies using various flame retardants have been conducted for the purpose of imparting flame retardancy to thermoplastic resins (see Patent Document 1).

  As an evaluation standard for flame retardancy, Subject No. 94 (UL94) of US Underwriters Laboratories is widely used. Even if the flame retardancy assessed by the UL94 is high, the flame is ignited. It was found that there was a thermoplastic resin composition having a short time.

JP-A-8-73684

  The subject of this invention is providing the thermoplastic resin composition which was excellent in the flame retardance, and was excellent in ignition resistance with the long time until a flame ignites.

The thermoplastic resin composition of the present invention contains (A) a thermoplastic resin , (B) a flame retardant, and (C) an igniting agent .
The (A) thermoplastic resin is at least one of a rubber-modified styrene resin and a polyolefin resin,
The (C) igniting agent is at least one of a dolomite compound and a hydrotalcite compound,
4-100 mass parts of said (B) flame retardant with respect to 100 mass parts of said (A) thermoplastic resins, 0.05-2.5 mass parts of said (C) ignition resistance agent,
The cracking furnace temperature at which the heat release rate measured based on ASTM D7309 Method A using a micro-scale combustion calorimeter reaches 20 W / g is 350 ° C. or higher, and the total calorific value at the cracking furnace temperature 200 to 600 ° C. is 38.5 kJ / g or less.

The present invention includes the following configuration as a preferred embodiment.
The content of 4-tert-butylcatechol included before Symbol rubber-modified styrene resin is less than 6 mg / kg.
Et al is, (D) contain a flame retardant agent, in particular, with respect to the (A) thermoplastic resin 100 parts by weight, said (D) a flame retardant aid containing 0.1-7 parts by weight about.

  According to the present invention, both the flame retardancy and the ignition resistance can be achieved by defining the cracking furnace temperature and the total calorific value at which the heat release rate measured using a microscale combustion calorimeter reaches 20 W / g. An excellent thermoplastic resin composition is obtained. Therefore, by using the thermoplastic resin composition of the present invention, molded articles such as building materials, automobile materials, miscellaneous goods, OA equipment, and home appliance casings excellent in flame retardancy and ignition resistance can be obtained.

It is a figure which shows an example of the heat dissipation rate characteristic curve obtained by the measurement based on ASTM D7309.

  As a result of various studies on the flame retardancy and ignition resistance of the thermoplastic resin composition, the present inventors measured using a microscale combustion calorimeter (MCC) based on ASTM D7309 method A. The present inventors achieved the present invention by discovering that the decomposition furnace temperature at which the heat release rate reaches 20 W / g and the total calorific value can be used as indicators of flame retardancy and ignition resistance of the thermoplastic resin composition.

  MCC is an apparatus for evaluating the combustion characteristics of combustible materials based on ASTM D7309, and has a decomposition furnace and a combustion furnace in the apparatus. In ASTM D7309, a sample is placed in an MCC cracking furnace, and the cracking furnace is heated at an arbitrary speed while flowing a mixed gas of nitrogen or nitrogen and oxygen into the cracking furnace, and the cracked gas generated therefrom is burned. It introduce | transduces into a furnace, burns cracked gas in presence of nitrogen and oxygen, and calculates a heat release rate (Heat Release Rate, HRR) from the amount of oxygen consumed. In such a method, the form of the sample is not limited, the reproducibility is good, and the combustion characteristics can be quantitatively shown.

In the present invention, based on ASTM D7309 Method A, the heat release rate (HRR) [W / g] per 1 g of sample is measured over time under the following conditions. Since the temperature of the cracking furnace is increased at a constant rate, the temperature of the cracking furnace corresponding to the measurement time is plotted on the horizontal axis, and the heat release rate obtained from the amount of oxygen consumed measured at the time is plotted on the vertical axis. A heat dissipation characteristic curve as shown is obtained. In addition, FIG. 1 is an example and is not limited to the heat dissipation rate characteristic curve according to the present invention.
Sample mass: 3.0mg
Decomposition furnace heating rate: 1.0 ° C / sec
Decomposition furnace temperature: 850 ° C
Combustion furnace temperature: 900 ° C (constant)
Decomposition furnace atmosphere: Nitrogen (anaerobic condition) (80 ml / min)
Combustion furnace atmosphere: oxygen / nitrogen mixed gas (oxygen 20 ml / min, nitrogen 80 ml / min)

  The thermoplastic resin composition of the present invention has a rising temperature of 350 ° C. or higher with the decomposition furnace temperature at which the heat dissipation rate reaches 20 W / g as the rising temperature of the heat dissipation rate in the heat dissipation rate characteristic curve. When the rising temperature is 350 ° C. or higher, the ignition resistance in the thermoplastic resin composition is high. For example, in the case of FIG.

  Further, the thermoplastic resin composition of the present invention has a total heat generation amount between the decomposition furnace temperature of 200 to 600 ° C., that is, a heat release rate at each measurement point in the temperature range in the heat release rate characteristic curve. ) Is 38.5 kJ / g or less. In the curve of FIG. 1, the horizontal axis represents the cracking furnace temperature, but since the cracking furnace temperature is raised at a constant rate, the horizontal axis corresponds to the time from the start of the temperature raising. Therefore, in the curve with time on the horizontal axis, the integral value of the heat release rate during the time when the cracking furnace temperature reaches 200 ° C. and 600 ° C. is the total calorific value between 200 to 600 ° C. If the total calorific value is 38.5 kJ / g or less, the flame retardancy is high.

  In the present invention, if the thermoplastic resin composition has a heat release rate characteristic where the rising temperature is 350 ° C. and the total calorific value is 38.5 kJ / g or less, excellent flame retardancy and ignition resistance. And is obtained.

  The thermoplastic resin (A) used in the present invention is not particularly limited as long as it is a polymer having thermoplasticity. Polystyrene (GPPS), acrylonitrile-styrene copolymer (AS resin), methyl methacrylate-styrene General-purpose styrene resins such as copolymer (MS resin), maleic anhydride-styrene copolymer, acrylic acid (or methacrylic acid) ester / styrene copolymer; high impact polystyrene (HIPS), acrylonitrile-butadiene-styrene Copolymer (ABS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), acrylonitrile-ethylenepropylene-styrene copolymer (AES resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), etc. Rubber-modified styrenic resin; poly Α-olefin polymers and copolymers of at least one of α-olefins having 2 to 10 carbon atoms, such as ethylene (PE), polypropylene (PP), and ethylene / propylene copolymers, and chlorinated polyethylenes thereof Olefin resins such as modified polymers and modified copolymers, cyclic olefin copolymers, etc .; ethylene copolymers such as ionomers, ethylene / vinyl acetate copolymers, ethylene / vinyl alcohol copolymers; polyvinyl chloride Resin (PVC), ethylene-vinyl chloride polymer, polyvinyl chloride resin such as polyvinylidene chloride (PVDC); heavy weight using one or more of acrylic acid (or methacrylic acid) ester such as polymethyl methacrylate (PMMA) Acrylic resins such as coalesces and copolymers; polyamide 6, polyamide 6,6, polyamide 6,1 Polyamide resins (PA) such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester resins such as polyethylene naphthalate; polyacetal (POM); polycarbonate (PC); polyarylate (PAR); PPE); polyphenylene sulfide (PPS); fluorine resin such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF); liquid crystal polymer; polyimide resin (PI), polyamideimide (PAI), polyetherimide (PEI), etc. Imide resins; ketone resins such as polyether ketone and polyether ether ketone (PEEK); sulfone resins such as polysulfone (PSU) and polyether sulfone (PES); urethane Fat (PU); polyvinyl acetate (PVAc); polyethylene oxide (PEO), polyvinyl alcohol (PVA); polyvinyl ethers, polyvinyl butyral, phenoxy resin, polylactic acid resin (PLA) and the like. These can be used alone or in combination of two or more. Of these, general-purpose styrene resins, rubber-modified styrene resins, olefin resins, acrylic resins, vinyl chloride resins, polycarbonate resins, polyester resins, polyamide resins, and polyphenylene ether are preferable, and rubber modified resins are particularly preferable. Styrenic resin, olefinic resin, acrylic resin, polycarbonate resin, polyester resin, and polyphenylene ether are preferable, and rubber-modified styrene resin and polyolefin resin such as polypropylene are more preferable.

  The styrene resin is obtained by polymerizing an aromatic vinyl compound monomer, and a styrene resin that has been rubber-modified by adding a rubbery polymer is referred to as a rubber-modified styrene resin. As the polymerization method, it can be produced by a known method, for example, a bulk polymerization method, a bulk / suspension two-stage polymerization method, a solution polymerization method or the like. As the aromatic vinyl compound monomer, known monomers such as styrene, α-methyl styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene can be used, and styrene is preferable. In addition, styrene monomers such as acrylonitrile, acrylic acid, methacrylic acid, acrylic acid (or methacrylic acid) ester, maleic anhydride, etc. that are copolymerizable with these aromatic vinyl compound monomers The body may be of a level that does not impair the performance of the thermoplastic resin composition. Furthermore, in the present invention, a polymer obtained by adding a crosslinking agent such as divinylbenzene to a styrene monomer may be used.

  The rubber-like polymer used for the rubber-modified styrene resin includes polybutadiene, styrene-butadiene random or block copolymer, polyisoprene, polychloroprene, styrene-isoprene random, block or graft copolymer, and ethylene-propylene rubber. , Ethylene-propylene-diene rubber, and the like, and in particular, random, block or graft copolymers of polybutadiene and styrene-butadiene are preferable. These may be partially hydrogenated, or may be used alone or in combination of two or more.

  The content of the rubbery polymer in the rubber-modified styrenic resin is preferably 3 to 15% by mass. When the content of the rubbery polymer is 3 to 15% by mass, a thermoplastic resin composition having an excellent balance between impact resistance and heat resistance can be obtained.

  The volume average particle diameter of the rubber-like polymer in the rubber-modified styrenic resin is preferably 0.1 to 5.0 μm mass%, particularly preferably 1.0 to 4.0 μm mass%. When the volume average particle diameter of the rubbery polymer is 0.1 to 5.0 μm, a significant impact resistance improving effect can be obtained.

  The content of 4-tert-butylcatechol (TBC) contained in the rubber-modified styrene resin is preferably 6 mg / kg or less. More preferably, it is 0.1-5 mg / kg. TBC is a polymerization initiator, and if the content of TBC is 6 mg / kg or less, the flame retardancy stability is increased, which is preferable.

  As a structure of the thermoplastic resin composition of this invention, it is preferable to contain (B) a flame retardant and (C) an igniting agent other than (A) thermoplastic resin.

  Examples of the flame retardant (B) used in the present invention include halogen-based flame retardants and phosphorus-based flame retardants.

  Halogen flame retardants include halogenated diphenyl ether compounds, halogenated diphenylalkane compounds, halogenated phthalimide compounds, tris (polyhalogenphenoxy) triazine compounds, halogenated bisphenol A polymers, halogenated styrene / butadiene block copolymers, halogens And styrene / butadiene random copolymer and halogenated styrene / butadiene graft copolymer. Preferred are halogenated diphenylalkane compounds, halogenated phthalimide compounds, and tris (polyhalogenphenoxy) triazine compounds.

  Examples of the halogenated diphenylalkane compound include compounds represented by the following formula [1].

In the above formula [1], R is an alkylene group having a structure of C _n H _2n (n is an integer of 1 to 10), X ₁ and X ₂ are each independently a halogen atom of an integer of 1 to 5, and X ₁ + X ₂ Represents ≧ 2.

  Examples of the halogenated diphenylalkane compound include diphenylmethane, 1,2-diphenylethane, 1,3-diphenylpropane, 1,6-diphenylhexane, and the like, trihalogen-substituted products, tetrahalogen-substituted products, and pentahalogen-substituted products. , Hexahalogen-substituted, heptahalogen-substituted, octahalogen-substituted, nonahalogen-substituted, and decahalogen-substituted. Preferred is decahalogen diphenylethane, and particularly preferred is decabromodiphenylethane.

  As a halogenated phthalimide compound, the compound represented by following formula [2] is mentioned.

In the above formula [2], R is an alkylene group having a structure of C _n H _2n (n is an integer of 0 to 6), X ₁ and X ₂ are each independently a halogen atom of an integer of 1 to 4, and X ₁ + X ₂ As the halogenated phthalimide compound representing ≧ 2, dihalogen substitution such as methylene-bis-phthalimide, ethylene-bis-phthalimide, propylene-bis-phthalimide, butylene-bis-phthalimide, pentylene-bis-phthalimide, hexylene-bis-phthalimide, etc. , Trihalogen-substituted, tetrahalogen-substituted, pentahalogen-substituted, hexahalogen-substituted, heptahalogen-substituted, and octahalogen-substituted. Preferred is ethylene-bis-tetrahalogen phthalimide, and particularly preferred is ethylene-bis-tetrabromophthalimide.

  Examples of the tris (polyhalogenphenoxy) triazine compound include a compound represented by the following formula [3].

In the formula (3) represents the X ₁ to X ₃ is a halogen atom integer from 1 to 3 independently _{X 1 + X 2 + X 3} ≧ 3.

  Examples of the tris (polyhalogenphenoxy) triazine compound include trihalogen trisubstituted, tetrahalogen substituted, pentahalogen substituted, hexahalogen substituted, heptahalogen substituted, octahalogen substituted, nonahalogen substituted triphenoxytriazine. . Tris (trihalogenphenoxy) triazine is preferable, and tris (tribromophenoxy) triazine is particularly preferable.

  Examples of phosphorus-based flame retardants include red phosphorus, organic phosphate ester compounds, phosphazene compounds, phosphinates, phosphonates, phosphoramide compounds, and the like. Preferred are organophosphate ester compounds and phosphazene compounds.

  Examples of the organic phosphate compound include compounds represented by the following formula [4].

In the formula (4), n is an integer of 1 to 5, Ar ₁ to Ar ₄ is phenyl or a 6 to 15 carbon atoms is an alkyl-substituted phenyl group, X is formula [X1] - [X5] It is a substituent represented by either.

  Examples of the organic phosphate compound include bisphenol A bis (diphenyl phosphate), resorcinol bis (diphenyl phosphate), 4,4′-biphenol bis (diphenyl phosphate), and 4,4′-biphenol bis (di-2,6-xy). Renyl phosphate) and the like. Bisphenol A bis (diphenyl phosphate) and resorcinol bis (diphenyl phosphate) are preferable.

  Examples of the phosphazene compound include a cyclic phosphazene compound represented by the following formula [5] and a linear phosphazene compound represented by the following formula [6].

  In said formula [5], n is an integer of 3-25, Ar is a C6-C15 phenyl group or an alkyl substituted phenyl group.

In the above formula [6], m is an integer of 3 to 1000, Ar is a phenyl group or alkyl-substituted phenyl group having 6 to 15 carbon atoms, and X is —N═P (OAr) ₃ or —N═P (O ) OAr, wherein Y is —P (OAr) ₄ or —P (O) (OAr) ₂ .

  In this invention, 4-30 mass parts is preferable with respect to 100 mass parts of (A) thermoplastic resins, and, as for the addition amount of (B) flame retardant, More preferably, it is 5-25 mass parts.

  Examples of the (C) refractory used in the present invention include silica (silicon dioxide), synthetic amorphous silica (silicon dioxide), aluminum silicate, magnesium silicate, calcium silicate, zirconium silicate, and diatomaceous earth. Silicon compounds such as aluminum hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, zirconium hydroxide, basic magnesium carbonate, zinc hydroxystannate, tin oxide hydrate, boron Metal hydroxides such as sand; metal oxides such as aluminum oxide, sodium oxide, potassium oxide, magnesium oxide, calcium oxide, barium oxide, titanium oxide, zinc oxide; zinc carbonate, sodium carbonate, potassium carbonate, calcium carbonate, carbonic acid Barium, magnesium carbonate, magnesium carbonate-calcium Metal hydrogen carbonate compounds, zinc hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, magnesium hydrogen carbonate-calcium metal hydrogen carbonate compounds; aluminum sulfate, barium sulfate, etc. Metal sulfate compounds: inorganic compound composites such as alumina hydrate, zeolite, sepiolite, hydrotalcite compound, dolomite compound, hydroxyapatite, diatomaceous earth. Preferred are dolomite compounds and hydrotalcite compounds.

The hydrotalcite compound is a compound composed of magnesium and aluminum. For example, a compound represented by _{Mg 6 Al 2 (OH) 16} CO 3 · nH 2 O.

  Dolomite compounds are industrially wide-ranging inorganic compounds that are produced in large quantities and are used in a wide range of industries such as steelmaking, pottery, building materials, agriculture, etc., so they can be obtained easily and inexpensively with stable quality. Is. As the dolomite-based compound used as an igniting agent, a derivative of dolomite that has been modified by subjecting natural dolomite or synthetic dolomite to firing, decontamination, or the like and without greatly changing the metal element composition can also be used.

  In the present invention, the amount of the (C) igniting agent added is preferably 0.05 to 2.5 parts by mass, more preferably 0.05 to 2.0 parts by mass, with respect to 100 parts by mass of the (A) thermoplastic resin. Part. 0.05 parts by mass or more can improve the ignition resistance of the thermoplastic resin composition, and 2.5 parts by mass or less is preferable because the molding processability of the thermoplastic resin composition is good.

  In the present invention, flame retardant aid (D) can be used as necessary. (D) The flame retardant aid functions to further enhance the flame retardant effect of (B) the flame retardant, for example, antimony oxide such as antimony trioxide, antimony tetroxide, antimony pentoxide, sodium antimonate; Boron compounds such as zinc oxide, barium metaborate, anhydrous zinc borate, and anhydrous boric acid; tin compounds such as stannic oxide, zinc stannate, and zinc hydroxystannate; molybdenum compounds such as molybdenum oxide and ammonium molybdate Compounds; zirconium compounds such as zirconium oxide; and zinc compounds such as zinc sulfide. Antimony oxide is preferable, and antimony trioxide is particularly preferable.

  In this invention, 0.1-7 mass parts is preferable with respect to 100 mass parts of (A) thermoplastic resins, and, as for the addition amount of (D) flame retardant adjuvant, 0.5-6 mass parts is especially preferable. The effect of improving the flame retardancy of the thermoplastic resin composition is obtained at 0.1 parts by mass or more, and the molded product having a good appearance is obtained at 7 parts by mass or less.

  In addition, the thermoplastic resin composition of the present invention has various additives such as dyes, pigments, anti-coloring agents, lubricants, antioxidants, anti-aging agents, light stabilizers, antistatic agents to the extent that the effects of the present invention are obtained. Known additives such as additives, fillers and compatibilizers, and modifiers such as colorants such as titanium oxide and carbon black can be added. These addition methods are not particularly limited, and are known methods, for example, (A) the thermoplastic resin to be used before the start of polymerization, during the polymerization in the middle of polymerization, or after the completion of polymerization, and (B) When blending a flame retardant, (C) an ignition resistant agent, or (D) a flame retardant aid, it can also be added in an extruder or a molding machine.

  A known mixing technique can be applied to the method for mixing the thermoplastic resin composition of the present invention. For example, a uniform thermoplastic resin composition can be obtained by melt-kneading a mixture preliminarily mixed with a mixing apparatus such as a mixer-type mixer, a V-type blender, and a tumbler-type mixer. There are no particular restrictions on the melt kneader. Suitable melt kneaders include Banbury mixers, kneaders, rolls, single screw extruders, special single screw extruders, and twin screw extruders. Furthermore, there is a method of separately adding an additive such as a flame retardant from the middle of a melt-kneading apparatus such as an extruder.

  In addition, a molding method for obtaining a molded product from the thermoplastic resin composition of the present invention includes injection molding.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

(A) Thermoplastic resin A-1: Rubber-modified impact-resistant polystyrene resin (HIPS) (rubber-like polymer is polybutadiene rubber, matrix-like rubber-like polymer content is 9.0% by mass, rubber-like polymer Volume average particle diameter of 3.0 μm, TBC content of the matrix part is 2.0 mg / kg)
A-2: Polypropylene resin (PP), “Novatec PP MA1B” manufactured by Nippon Polypro Co., Ltd.

<Measurement of rubbery polymer content>
Dissolve the sample in chloroform, add a certain amount of iodine monochloride / carbon tetrachloride solution, leave it in the dark for about 1 hour, add 15% by weight potassium iodide solution and 50 ml of pure water, and add excess iodine monochloride. The solution was titrated with 0.1N sodium thiosulfate / ethanol aqueous solution and calculated from the amount of added iodine monochloride.

<Measurement of volume average particle diameter of rubbery polymer>
The sample was dissolved in dimethylformamide and measured with a laser diffraction particle size distribution apparatus (Laser diffraction particle analyzer “LS-230” manufactured by Beckman Coulter, Inc.).

<Measurement of TBC content>
Dissolve 2 g of the sample in 100 ml of tetrahydrofuran (THF), remove the rubber-like dispersed particles with a centrifuge (“H-2000B” (rotor: H) manufactured by Kokusan Co., Ltd.), collect 10 ml of the supernatant, 200 μl of N, O-bis (trimethylsilyl) trifluoroacetamide was added, and the TBC content in the sample was measured with a gas chromatograph / mass spectrometer (GC / MS).
Apparatus: “HP7890 / HP5974” manufactured by Agilent Technologies
Column: “DB-5MS” manufactured by Agilent Technologies
Oven: 50 ° C
Inlet: 300 ° C
Carrier: helium, 1 ml / min
Detector: Mass spectrometer

(B) Flame retardant B-1: Decabromodiphenylethane, “SAYTEX 8010” manufactured by Albemarle
B-2: Ethylene-bis-tetrabromophthalimide, “SAYTEX BT-93” manufactured by Albemarle
B-3: 2,4,6-tris (2,4,6-tribromophenoxy) -1,3,5-triazine, “Pyroguard SR245” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
B-4: Bisphenol A bis (diphenyl phosphate), “CR-741” manufactured by Daihachi Chemical Co., Ltd.
B-5: Resorcinol bis (diphenyl phosphate), manufactured by Daihachi Chemical Co., Ltd. “CR-733S”
B-6: Phosphazene compound, “Ravitor FP-110” manufactured by Fushimi Pharmaceutical Co., Ltd.

(C) Ignition agent C-1: Dolomite compound, “Pleniser HC-100B” manufactured by Ajinomoto Fine Techno Co., Ltd.
C-2: Hydrotalcite compound, “MC-63A” manufactured by Nitto Kasei Corporation

(D) Flame retardant aid D-1: Antimony trioxide, “AT-3CN” manufactured by Suzuhiro Chemical Co., Ltd.

  The above-mentioned (A) thermoplastic resin, (B) flame retardant, (C) igniting agent and (D) flame retardant aid are blended in parts by mass shown in Tables 1 and 2, and Henschel mixer (Nippon Coke Kogyo Co., Ltd.). Premixed with “FM20B”). The premixed raw material was supplied to a twin screw extruder (“TEM26SS” manufactured by Toshiba Machine Co., Ltd.) to form a strand, which was cooled to water and led to a pelletizer to be pelletized. At this time, the cylinder temperature was 230 ° C. and the supply amount was 30 kg / hour.

  Using the obtained pellets, MCC ("MCC-3" manufactured by DETAK) was used, and based on ASTM D7309 Method A, the heat dissipation rate [W / g] was measured under the above-described conditions, the rising temperature [° C], The total calorific value [kJ / g] at the decomposition furnace temperature of 200 to 600 ° C. was determined. Moreover, using the obtained pellet, ignition resistance and flame retardance were evaluated by the method shown below. The results are shown in Tables 1 and 2.

<Ignition resistance>
Based on the UL94 5V Plaque test method, the time until a flame ignites on a 3.0 mm thick test piece was evaluated. If the time until ignition was 5 seconds or longer, the test was accepted. In addition, the test piece for combustion (150x150x3.0mm) was produced using the injection molding machine ("J100E-P" by Nippon Steel Works). At this time, the cylinder temperature of the injection molding machine was 220 ° C., and the mold temperature was 45 ° C.

<Flame retardance>
A test piece for combustion having a length of 127 mm, a width of 12.7 mm, and a thickness of 2.5 mm was molded using an injection molding machine (“J100E-P” manufactured by Nippon Steel Works). At this time, the cylinder temperature of the injection molding machine was 220 ° C., and the mold temperature was 45 ° C. Using this test piece, the combustibility was evaluated in accordance with the vertical combustion test method of UL94. When this test method did not satisfy V-2, it was determined as NG.

  From Tables 1 and 2, the cracking furnace temperature (rising temperature) at which the heat dissipation rate reaches 20 W / g is 350 ° C. or higher, and the total heat generation at the cracking furnace temperature 200 ° C. to 600 ° C. is 38.5 kJ / g or lower. In the examples, both the ignition resistance and flame retardancy are excellent, whereas in the comparative examples in which any one of the above-mentioned decomposition furnace temperature and total calorific value is not satisfied, the ignition resistance Or it turns out that a flame retardance or both is inferior to an Example.

Claims (4)

(A) a thermoplastic resin , (B) a flame retardant, and (C) an igniting agent ,
The (A) thermoplastic resin is at least one of a rubber-modified styrene resin and a polyolefin resin,
The (C) igniting agent is at least one of a dolomite compound and a hydrotalcite compound,
4-100 mass parts of said (B) flame retardant with respect to 100 mass parts of said (A) thermoplastic resins, 0.05-2.5 mass parts of said (C) ignition resistance agent,
The cracking furnace temperature at which the heat release rate measured based on ASTM D7309 Method A using a micro-scale combustion calorimeter reaches 20 W / g is 350 ° C. or higher, and the total calorific value at the cracking furnace temperature 200 to 600 ° C. is 38.5 kJ / The thermoplastic resin composition characterized by being below g. The thermoplastic resin composition according to claim 1 , wherein the content of 4-tert-butylcatechol contained in the rubber-modified styrene resin is 6 mg / kg or less. Further, the thermoplastic resin composition according to claim 1 or 2, characterized in that it contains (D) a flame retardant aid. The thermoplastic resin composition according to claim 3 , wherein 0.1 to 7 parts by mass of the flame retardant aid (D) is contained with respect to 100 parts by mass of the (A) thermoplastic resin.

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