JP6436915B2 - Flame retardant polyamide resin composition and molded article comprising the same - Google Patents

Description

  The present invention relates to a flame retardant polyamide resin composition.

Polyamide resins are widely used as molding materials. In recent years, there has been a demand for higher performance of polyamide resins, and in order to meet this demand, fillers are often added, and polyamide resin compositions having a filler content exceeding 50% by mass are not uncommon. .
The resin composition has a problem that the moldability is lowered because the melt viscosity increases as the filler content increases. Therefore, in order to reduce the melt viscosity of the resin composition, a melt viscosity reducing agent is blended in the resin composition. For example, Patent Document 1 discloses that rosin is blended as a melt viscosity reducing agent. Document 2 discloses that a polyfunctional allyl compound or a dimer acid-based thermoplastic resin is blended as a melt viscosity reducing agent.
However, when a flame retardant is added to the resin composition described in the above-mentioned patent document having a high filler content in order to impart further flame retardancy, the mechanical properties of the molded product may be deteriorated. . Moreover, in the polyamide resin composition containing a melt viscosity reducing agent, as the melt viscosity decreases, it becomes easy to drip at the time of combustion, and flame retardancy may decrease. Therefore, combined use of a flame retardant and a melt viscosity reducing agent in a polyamide resin has not been generally performed.

International Publication No. 2013/0669365 International Publication No. 2010/084845

  The present invention solves the above-described problem, and even if a flame retardant is added to a polyamide resin composition having a high filler content to impart flame retardancy, the mechanical properties are not deteriorated. It is to provide a flame retardant polyamide resin composition.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problem can be solved by blending coated red phosphorus as a flame retardant into a resin composition containing a polyamide resin, a filler, and rosin. The headline, the present invention has been reached.

That is, the gist of the present invention is as follows.
(1) A flame retardant polyamide resin composition containing a polyamide resin (A), a filler (B), a coated red phosphorus (C) and a rosin (D),
The mass ratio (A / B) of the polyamide resin (A) and the filler (B) is 50/50 to 20/80,
The content of the coated red phosphorus (C) is 1 to 10 parts by mass and the content of rosin (D) is 0.5 to 100 parts by mass with respect to 100 parts by mass of the polyamide resin (A) and the filler (B). 5 parts by mass,
A flame-retardant polyamide resin composition having a melt viscosity at 280 ° C. of 900 Pa · s or less.
(2) The flame retardant polyamide resin composition according to (1), wherein the filler (B) has an average particle size of 50 μm or more.
(3) The flame retardant polyamide resin composition according to (1) or (2), wherein the thermal conductivity is 5 W / (m · K) or more.
(4) A molded article obtained by molding the flame retardant polyamide resin composition according to any one of (1) to (3).

According to the present invention, when coated red phosphorus is added as a flame retardant to a polyamide resin composition having a high filler content, a molded article having flame retardancy can be obtained without deteriorating mechanical properties. .
Moreover, the polyamide resin composition containing coated red phosphorus as a flame retardant exhibits the surprising effect that the flame retardancy is improved without lowering the flame retardancy due to the melt viscosity lowering effect of rosin.

Hereinafter, the present invention will be described in detail.
The flame retardant polyamide resin composition of the present invention contains a polyamide resin (A), a filler (B), coated red phosphorus (C), and rosin (D).

  Examples of the polyamide resin (A) used in the present invention include polycoupleramide (polyamide 6), polytetramethylene adipamide (polyamide 46), polyhexamethylene adipamide (polyamide 66), polycoupleramide / polyhexamethylene adipamide. Copolymer (polyamide 6/66), polyundecamide (polyamide 11), polycapramide / polyundecanamide copolymer (polyamide 6/11), polydodecamide (polyamide 12), polycoupler / polydodecanamide copolymer (polyamide 6/12), polyhexamethylene Sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polyundecamethylene adipamide (polyamide 116), polyhexamethylene isophthalamide (polyamide 6I), poly Hexamethylene terephthalamide (polyamide 6T), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 6T / 6I), polycapramide / polyhexamethylene terephthalamide copolymer (polyamide 6 / 6T), polycoupleramide / polyhexamethylene isophthalamide Copolymer (polyamide 6 / 6I), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (polyamide 66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6I), polytrimethyl Hexamethylene terephthalamide (polyamide TMDT), polybis (4-aminocyclohexyl) methane dodecamide (polyamide PACM 2), polybis (3-methyl-4-aminocyclohexyl) methane dodecamide (polyamide dimethyl PACM12), polymetaxylylene adipamide (polyamide MXD6), polynonamethylene terephthalamide (polyamide 9T), polydecamethylene terephthalamide ( Polyamide 10T), polyundecamethylene terephthalamide (polyamide 11T), polydodecamethylene terephthalamide (polyamide 12T), and mixtures or copolymers thereof. Of these, polyamide 6 and polyamide 66 are preferable from the viewpoint of economy.

  The filler (B) used in the present invention is not particularly limited, but is used for the purpose of improving mechanical characteristics, thermal characteristics, etc., conductive, thermal conductivity, magnetism, piezoelectricity, electromagnetic wave absorption, ultraviolet rays. The thing used for the purpose of providing absorption etc. can be mentioned.

  Examples of the filler (B) include acetylene black, ketjen black, carbon nanotube, carbon nanofiber, metal powder (silver, copper, aluminum, titanium, nickel, tin, iron, stainless steel, etc.), conductive zinc oxide, Tin oxide, indium oxide, various ferrites, magnetic iron oxide, aluminum oxide, magnesium oxide, zinc oxide, magnesium carbonate, silicon carbide, aluminum nitride, boron nitride, silicon nitride, carbon, graphite, barium titanate, lead zirconate titanate , Potassium titanate, zonotlite, mica, talc, montmorillonite, hydrotalcite, calcium carbonate, zinc carbonate, wollastonite, barium sulfate, molybdenum disulfide, teflon (registered trademark) powder, silica, glass beads, glass balloon, oxidation titanium Aluminum hydroxide, magnesium hydroxide, antimony trioxide, boric acid, zinc borate, cerium oxide, calcium oxide, silica gel, sepiolite, activated carbon, zeolite, tungsten, zirconium oxide, cellulose fine particles, wood powder, okara, fir shell, Natural fibers such as glass fiber, carbon fiber, graphitized carbon fiber, aramid fiber, metal fiber, stainless steel fiber, silica fiber, silica / alumina fiber, zirconia fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, kenaf and hemp Is mentioned.

  The average particle size of the filler (B) is preferably 50 μm or more. By using a filler having an average particle size of 50 μm or more, the fluidity of the resin composition can be improved, and the effect of suppressing ignition of the coated red phosphorus (C) can be enhanced during kneading and molding.

By using a thermally conductive filler as the filler (B), thermal conductivity can be imparted to the thermally conductive resin composition. The thermal conductivity of the resin composition containing the thermally conductive filler is preferably 5 W / (m · K) or more.
The heat conductive filler may be either conductive or insulating, but its thermal conductivity is preferably 5 W / (m · K) or more. The thermal conductivity of the thermally conductive filler can be measured using the sintered product. Specific examples of the thermally conductive filler (representing a representative value of thermal conductivity (unit: W / (m · K)) in parentheses), talc (5-10), aluminum oxide (36) , Magnesium oxide (60), zinc oxide (25), magnesium carbonate (15), silicon carbide (160), aluminum nitride (170), boron nitride (210), silicon nitride (40), carbon (10 to several hundreds) , Inorganic fillers such as graphite (10 to several hundred), silver (427), copper (398), aluminum (237), titanium (22), nickel (90), tin (68), iron (84), Examples thereof include metallic fillers such as stainless steel (15). These may be used alone or in combination. Of these, graphite and boron nitride are preferably used because of their high thermal conductivity when blended with the polyamide resin (A). Moreover, it is preferable to use a talc and magnesium oxide from an economical point.

  Examples of the form of graphite include a spherical shape, a powder shape, a fiber shape, a needle shape, a scale shape, a whisker shape, a microcoil shape, and a nanotube shape. Among these, scale-like graphite is more preferable because it can increase the heat conduction efficiency when blended with the polyamide resin (A).

  Examples of the form of talc include a plate shape, a scale shape, a scale shape, and a flake shape. Among these, scaly talc and lamellar talc are more preferable because they are easily oriented in the surface direction when formed into a molded body, and as a result, the thermal conductivity can be increased.

  Examples of the form of boron nitride include a plate shape, a scale shape, and a flake shape. Among these, scaly boron nitride is more preferable because it is easily oriented in the surface direction when formed into a molded body, and as a result, the thermal conductivity can be increased. The crystal system of boron nitride is not particularly limited, and boron nitride having any crystal structure such as hexagonal system, cubic system, and the like is applicable. Of these, boron nitride having a hexagonal crystal structure is preferable because of its high thermal conductivity.

  Examples of the form of magnesium oxide include a spherical shape, a fiber shape, a spindle shape, a rod shape, a needle shape, a cylindrical shape, and a column shape. Among these, spherical magnesium oxide is more preferable because it can improve fluidity.

  The filler (B) may be surface-treated with a silane coupling agent or a titanium coupling agent in order to improve the adhesion with the polyamide resin (A). Examples of the silane coupling agent include γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyldimethoxymethyl. Epoxysilane couplings such as aminosilane coupling agents such as silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane Agents. Examples of the titanium coupling agent include isopropyltristearoyl titanate, isopropyltridodecylbenzenesulfonyl titanate, and tetraisopropylbis (dioctyl phosphite) titanate. These may be used alone or in combination.

  In the present invention, the mass ratio (A / B) of the polyamide resin (A) and the filler (B) needs to be 50/50 to 20/80, and is 30/70 to 20/80. It is preferable. When the polyamide resin (A) is less than 20% by mass, the resin composition is remarkably lowered in fluidity, and the coated red phosphorus (C) may ignite during kneading or molding. In this case, if the rosin (D) of the melt viscosity reducing agent is blended beyond the range specified in the present invention, it is possible to improve the fluidity, but it is not preferable because the mechanical properties are remarkably lowered. . On the other hand, when the polyamide resin (A) exceeds 50% by mass, the resin composition has fluidity.

  In the present invention, it is necessary to use coated red phosphorus (C) as a flame retardant. In general, red phosphorus reacts gradually with water even at room temperature to generate phosphine gas, and this phenomenon tends to increase as the temperature increases. Since phosphine gas acts as a powerful reducing agent, when it is present at a high concentration, it reacts with oxygen in the air to cause ignition. However, since the reaction between red phosphorus and water can be suppressed by using coated red phosphorus, ignition during kneading or molding can be prevented.

The average particle diameter of the coated red phosphorus (C) is preferably from 0.01 to 35 μm, more preferably from 0.1 to 30 μm, from the viewpoint of flame retardancy and mechanical properties.
The coated red phosphorus (C) may be used in the form of chips or powder as it is during kneading or molding, but a masterbatch prepared in advance and containing the coated red phosphorus (C) at a high concentration is used. It is easier to adjust the concentration of the coated red phosphorus (C).
Examples of the method for producing coated red phosphorus include a method of covering the surface of red phosphorus with aluminum hydroxide or magnesium hydroxide powder and a method of coating red phosphorus with a thermosetting resin.
Examples of commercially available coated red phosphorus include “NOVA EXCEL 140” and “NOVA EXCEL 140F” manufactured by Rin Chemical Industry Co., Ltd.

  The content of the coated red phosphorus (C) needs to be 1 to 10 parts by mass with respect to 100 parts by mass in total of the polyamide resin (A) and the filler (B), and 2 to 6 parts by mass. Preferably there is. When the content of the coated red phosphorus (C) is less than 1 part by mass, the resin composition has insufficient flame retardancy. On the other hand, when the content exceeds 10 parts by mass, the resin composition is flame retardant. There is no improvement in the properties, and the coated red phosphorus (C) acts as a filler, so that the fluidity is remarkably lowered and may ignite during kneading or molding.

  The rosin (D) used in the present invention is a diterpenic acid compound called resin acid (rosin acid). Examples of rosin (D) include natural rosin, modified rosin, and polymerized rosin.

  Natural rosin is a mixture of resin acids collected from Pinaceae plants and is divided into gum rosin, wood rosin and tall oil rosin according to the production method. The main component of the resin acid is abietic acid, and further includes neoabietic acid, dehydroabietic acid, parastrinic acid, pimaric acid, isopimaric acid, sandaracopimaric acid, levopimaric acid, and the like. Modified rosin is a modified natural rosin such as hydrogenated rosin such as dihydroabietic acid and tetrahydroabietic acid, disproportionated rosin such as dehydroabietic acid and dihydroabietic acid, acrylic acid, maleic acid, fumaric acid. Examples include acid-modified rosin obtained by modifying natural rosin with an acid or the like, and ester forms thereof. The polymerized rosin is a product obtained by reacting natural rosins or modified rosins, and examples thereof include dimerized products and trimerized products.

  The content of rosin (D) needs to be 0.5 to 5 parts by mass with respect to 100 parts by mass in total of the polyamide resin (A) and the filler (B). Preferably there is. If the content of rosin (D) is less than 0.5 parts by mass, a sufficient fluidity improving effect cannot be obtained, so that the resin composition has a high melt viscosity and is coated with red phosphorus (C) during kneading and molding. May ignite. On the other hand, if the content of rosin (D) exceeds 5 parts by mass, the mechanical properties of the resulting molded article will be lowered, and the flame viscosity may be lowered due to excessive decrease in melt viscosity.

  The acid value of rosin (D) is preferably 60 mgKOH / g or more, more preferably 100 mgKOH / g or more, and further preferably 130 mgKOH / g or more. By using rosin (D) having an acid value of 60 mgKOH / g or more, the fluidity can be improved with a small amount.

  The softening temperature of rosin (D) is preferably 110 ° C. or higher, and more preferably 120 ° C. or higher. By using rosin (D) having a softening temperature of 110 ° C. or higher, decomposition of rosin (D) itself can be suppressed, and rosin (D) can be prevented from bleeding out from a molded body after molding. Can do.

  The flame-retardant polyamide resin composition of the present invention needs to have a melt viscosity at 280 ° C. of 900 Pa · s or less, preferably 800 Pa · s or less. When the melt viscosity of the resin composition exceeds 900 Pa · s, the coated red phosphorus (C) may be lost due to a high shearing force applied during kneading or molding.

  In the flame-retardant polyamide resin composition of the present invention, a heat stabilizer, an antioxidant, a crystal nucleating agent, a compatibilizing agent, a pigment, a weathering agent, a lubricant, a release agent, a charge, unless the effects of the present invention are impaired. Additives such as inhibitors may be added. Examples of the heat stabilizer and the antioxidant include halides such as hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, and alkali metals. Examples of the crystal nucleating agent include a sorbitol compound, benzoic acid, a metal salt of the compound, and a phosphate ester metal salt. Examples of the compatibilizer include ionomer compatibilizers, oxazoline compatibilizers, elastomer compatibilizers, reactive compatibilizers, and copolymer-based compatibilizers. These additives may be used alone or in combination. In addition, the method of mixing these with the flame-retardant polyamide resin composition of this invention is not specifically limited.

  The flame-retardant polyamide resin composition of the present invention comprises a polyamide resin (A), a filler (B), a coated red phosphorus (C), and a rosin (D), and various additives as required. It can be produced by melt kneading using a typical extruder such as a single screw extruder, a twin screw extruder, a roll kneader, or a Brabender. At this time, it is effective to use a static mixer or a dynamic mixer together. In order to improve the kneading state, it is preferable to use a twin screw extruder. Although the addition method of a filler (B) is not specifically limited, When using an extruder, a filler (B) can be added from a hopper or a side feeder.

  The flame-retardant polyamide resin composition of the present invention may be molded into a desired shape using a generally known melt molding method such as injection molding, compression molding, extrusion molding, transfer molding, sheet molding, etc. it can.

  Molded products formed by molding the flame-retardant polyamide resin composition of the present invention include semiconductor elements, sealing materials such as resistors, connectors, sockets, relay parts, coil bobbins, optical pickups, oscillators, computer-related parts, etc. To release heat from electronic parts such as electric / electronic parts, VTR, TV, iron, air conditioner, stereo, vacuum cleaner, refrigerator, rice cooker, lighting fixtures, and other electronic parts such as heat dissipation sheets, heat sinks and fans. Heat radiating parts, lamp sockets, lamp reflectors, lamp fixtures and other lighting fixture parts, compact discs, laser discs, acoustic product parts such as speakers, optical cable ferrules, mobile phone, fixed telephones, facsimiles, communication equipment parts such as modems, Copying machines such as separation nails and heater holders, printing agencies Machine parts such as parts, impellers, fan gears, gears, bearings, motor parts and cases, automotive mechanism parts, engine parts, parts in the engine room, electrical parts, interior parts, microwave cooking pots, heat resistance Examples include cooking utensils such as tableware, aircraft, spacecraft, space equipment parts, and sensor parts.

EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these.
The evaluation methods used in Examples and Comparative Examples of the present invention are shown below.

(1) Acid value of rosin It was measured according to the method described in JIS standard K5902.

(2) Bending strength and flexural modulus The resin composition pellets were subjected to a cylinder temperature of 280 ° C., a mold temperature of 100 ° C., an injection time of 15 seconds, and a cooling time of 20 using an injection molding machine (Nex110-12E manufactured by Nissei Plastic Industry Co., Ltd.). The injection molding was performed in seconds, and a dumbbell molded piece (test part 127 mm × 12.7 mm × 3.2 mm) for evaluation of bending strength and flexural modulus was produced.
Using the obtained bending strength and flexural modulus evaluation dumbbell molded piece, the measurement was performed according to the method described in ASTM standard D-790.

(3) Deflection temperature under load (DTUL)
The resin composition pellets are injection molded with a cylinder temperature of 280 ° C., a mold temperature of 100 ° C., an injection time of 15 seconds, and a cooling time of 20 seconds using an injection molding machine (Nex110-12E manufactured by Nissei Plastic Industry Co., Ltd.) for DTUL evaluation. A molded piece (127 mm × 10 mm × 1.2 mm) was produced.
Using the obtained molded piece for DTUL evaluation, the deflection temperature under a load of 1.8 MPa was measured according to the method described in ASTM standard D-648.

(4) Flame retardancy Resin composition pellets are injected at a cylinder temperature of 280 ° C., a mold temperature of 100 ° C., an injection time of 15 seconds, and a cooling time of 20 seconds using an injection molding machine (Nex110-12E manufactured by Nissei Plastic Industry Co., Ltd.). Molded to produce a flame retardant evaluation molded piece (127 mm × 12.7 mm × 1.588 mm).
It evaluated according to UL-94 using the obtained molded piece for flame retardance evaluation.

(5) Melt viscosity The resin composition pellets were measured for melt viscosity at a predetermined temperature using a descending flow tester (manufactured by Shimadzu Corporation). The measurement temperature was all 280 ° C., and the orifice used had a diameter of 1 mm × length of 10 mm.

(6) Presence or absence of ignition Using an injection molding machine (Nex110-12E manufactured by Nissei Plastic Industry Co., Ltd.), weighing 40 cc of pellets of the resin composition, holding it for 3 minutes, and then discharging it at an injection speed of 100 mm / s Repeatedly, the state of the nozzle tip was observed to determine the presence or absence of ignition. The cylinder temperature was set at 280 ° C.

(7) Thermal conductivity The thermal conductivity λ was calculated by the following equation as the product of the thermal diffusivity α, the density ρ, and the specific heat Cp obtained by the following method.
λ = α ・ ρ ・ Cp
λ: thermal conductivity (W / (m · K))
α: Thermal diffusivity (m ² / sec)
ρ: Density (g / m ³ )
Cp: Specific heat (J / g · K)
The thermal diffusivity α was measured using a laser flash method thermal constant measuring device (TC-7000, ULVAC-RIKO, Inc.) in the resin flow direction of the evaluation molded pieces obtained in Examples and Comparative Examples. The density ρ was measured using an electronic hydrometer (ED-120T manufactured by Mirage Trading Co., Ltd.). The specific heat Cp was measured using a differential scanning calorimeter (DSC-7, manufactured by Perkin Elmer Co.) at a temperature increase rate of 10 ° C./min.

The raw materials used in Examples and Comparative Examples of the present invention are shown below.
(1) Polyamide resin (A)
PA6: polyamide 6 resin (relative viscosity 1.9, density 1.13 cm ³ )

(2) Filler (B)
GrA: scaly graphite (manufactured by Nippon Graphite Industry Co., Ltd., average particle size 130 μm, thermal conductivity 100 W / (m · K), density 2.25 g / cm ³ )
GrB: scaly graphite (manufactured by Nippon Graphite Industries Co., Ltd., average particle size 60 μm, thermal conductivity 100 W / (m · K), density 2.25 g / cm ³ )
GrC: scaly graphite (manufactured by Nippon Graphite Industry Co., Ltd., average particle size 5 μm, thermal conductivity 100 W / (m · K), density 2.25 g / cm ³ )
GF: Glass fiber (Owens Corning, average fiber diameter 10 μm, average fiber length 3 mm, density 2.50 g / cm ³ )
TC: scaly talc (manufactured by Nippon Talc Co., Ltd., average particle size 23 μm, thermal conductivity 5-10 W / (m · K), density 2.70 g / cm ³ )
MgO: spherical magnesium oxide (manufactured by Tateho Chemical Co., Ltd., average particle size 30 μm, thermal conductivity 50 W / (m · K), density 3.58 g / cm ³ )
BN: Hexagonal scaly boron nitride (manufactured by Electrochemical Co., Ltd., average particle size 15 μm, thermal conductivity 210 W / (m · K), density 2.26 g / cm ³ )

(3) Flame retardant (3-1) Coated red phosphorus (C)
C1: coated red phosphorus (manufactured by Rin Chemical Industry, Nova Excel 140, average particle size 25-35 μm)
C2: coated red phosphorus (manufactured by Phosphor Chemical Co., Ltd., Nova Excel 140F, average particle size 5 to 15 μm)
(3-2) Brominated flame retardant / FR: Brominated flame retardant (IC-2, manufactured by ICL-IP)
(3-3) Flame retardant aid Sb: Antimony trioxide (Nippon Seiko Co., Ltd., PATOX-M)

(4) Melt viscosity reducing agent (4-1) Rosin (D)
D1: maleated rosin (manufactured by Arakawa Chemical Industries, Marquide No. 31, acid value 188 mg KOH / g, softening temperature 141 ° C.)
D2: maleated rosin (manufactured by Arakawa Chemical Industries, Marquide No. 33, acid value 317 mgKOH / g, softening temperature 153 ° C.)
D3: Rosin (Arakawa Chemical Industries, KR-85, acid value 165 to 175 mg KOH / g, softening temperature 80 to 87 ° C.)
(4-2) Polyfunctional allyl compound E1: triallyl isocyanate (TAIC manufactured by Nippon Kasei Co., Ltd.)
(4-3) Dimer acid-based polyamide resin / E2: Dimer acid (manufactured by Tsukino Food Industry Co., Ltd., without hydrogenation) and 1,3-bis (aminomethyl) benzene were combined with dimer acid / 1,3-bis ( Aminomethyl) benzene = 46.5 / 53.5 (molar ratio) was charged into a reaction vessel, reacted at 240 ° C. for 2 hours, discharged after completion of the reaction, and cut into dimer acid-based polyamide resin pellets obtained by cutting. used. The melt flow rate at 230 ° C. and a load of 21.18 N was 1800 g / 10 minutes.

Example 1
In a main hopper of a twin screw extruder (TEM 26SS manufactured by Toshiba Machine Co., Ltd., screw diameter 26 mm), 50 parts by mass of polyamide resin (PA6), 50 parts by mass of filler (GrA), 4 parts by mass of coated red phosphorus (C1) Then, 2 parts by mass of rosin (D1) was supplied, melted and kneaded at 260 ° C., extruded into a strand, cooled and solidified, and then cut to obtain pellets of a resin composition.

Examples 2-20, Comparative Examples 1-11
Except changing the composition of the resin composition as shown in Tables 1 and 2, the same operation as in Example 1 was performed to obtain a pellet of the resin composition. Glass fiber (GF) was supplied from the middle by a side feeder.

  The evaluation result of the resin composition obtained in Examples 1-20 and Comparative Examples 1-11 is shown to Tables 1-2.

The resin compositions of Examples 1 to 20 all had a flame retardancy evaluation of V-1 or higher and a melt viscosity of 900 Pa · s or lower. In all cases, no ignition was observed in the ignitability test.
The resin composition of Example 3 has the same bending strength and bending elastic modulus as the resin composition of Comparative Example 1 that does not contain the coated red phosphorus (C), and contains the coated red phosphorus (C). However, the mechanical properties were not impaired. In the resin composition of Comparative Example 2 in which the coated red phosphorus (C) was blended with the resin composition of Comparative Example 1 containing no coated red phosphorus (C) or rosin (D), the flame retardancy was improved to V-1. However, in the resin composition of Example 3 further blended with rosin (D), the flame retardancy was improved to V-0. This further improvement in flame retardance is presumed to be due to the interaction between rosin (D) and coated red phosphorus (C).
Moreover, the resin composition of the Example using graphite (GrA, GrB) and boron nitride (BN) as a filler had a thermal conductivity of 5 W / (m · K) or more.

Since the resin compositions of Comparative Examples 1 and 4 did not contain the coated red phosphorus (C) or had a low content, the flame retardancy was low and was V-2 or less.
Since Comparative Example 2 does not contain rosin (D), Comparative Example 5 has too much content of coated red phosphorus (C), and Comparative Example 6 has too much content of filler (B). Since No. 7 used the filler (B) having an average particle diameter of 5 μm, all of the resin compositions had a high melt viscosity, and ignition was observed in the ignitability test.
Since the resin composition of Comparative Example 3 contained a large amount of rosin (D), the bending strength and the bending elastic modulus were lowered.
Since the resin composition of Comparative Example 8 uses a brominated flame retardant (FR) as a flame retardant, the resin composition of Comparative Example 1 that does not contain a flame retardant and a comparison that contains coated red phosphorus (C) as a flame retardant Compared with the resin composition of Example 2, the bending strength and the flexural modulus were significantly reduced. In Comparative Example 9, even when rosin (D) is blended with the resin composition of Comparative Example 8 containing brominated flame retardant (FR) as a flame retardant, rosin (D) and brominated flame retardant (FR) Did not interact with each other, and flame retardancy did not improve.
In the resin compositions of Comparative Examples 10 and 11, the flame retardant is coated red phosphorus (C), but a polyfunctional allyl compound other than rosin (D) or a dimer acid-based thermoplastic resin is used as the melt viscosity reducing agent. Therefore, the flame retardancy was lower than that of the resin composition of Comparative Example 2 that did not contain a melt viscosity reducing agent, and V-2 was obtained.

Claims (4)

A flame retardant polyamide resin composition comprising a polyamide resin (A), a filler (B), a coated red phosphorus (C) and a rosin (D),
The mass ratio (A / B) of the polyamide resin (A) and the filler (B) is 50/50 to 20/80,
The content of the coated red phosphorus (C) is 1 to 10 parts by mass and the content of rosin (D) is 0.5 to 100 parts by mass with respect to 100 parts by mass of the polyamide resin (A) and the filler (B). 5 parts by mass,
A flame-retardant polyamide resin composition having a melt viscosity at 280 ° C. of 900 Pa · s or less.   The flame retardant polyamide resin composition according to claim 1, wherein the filler (B) has an average particle size of 50 μm or more.   The flame-retardant polyamide resin composition according to claim 1, wherein the thermal conductivity is 5 W / (m · K) or more. The molded object formed by shape | molding the flame-retardant polyamide resin composition in any one of Claims 1-3.