JPH11241019A - Flame-retardant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition not only having excellent moldability but also improved in hygroscopicity, dimensional stability upon moisture absorption, and blister resistance by incorporating a polyamide 4, 6 resin with an arylene sulfide resin and a higher aliphatic polyamide resin and adding a flame retardant to the obtained mixture. SOLUTION: A polyamide 4, 6 resin is incorporated with a polyarylene sulfide resin and a higher aliphatic polyamide resin. The polyamide 4, 6 resin is used in an amount of, usually, 5-90 wt.%, desirably, 20-90 wt.% based on the total weight of the three components. The polyarylene sulfide resin is used in an amount of, usually, 5-90 wt.%, desirably, 5-75 wt.%, and the higher aliphatic polyamide resin is used in an amount of, usually, 5-90 wt.%, desirably, 5-75 wt.%. Usually, 5-70 pts.wt. flame retardant such as polybromostyrene is added to 100 pts.wt. total of the three components. This composition may optionally contain an inorganic filler such as glass fibers or asbestos fibers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is excellent in mechanical properties, low in hygroscopicity, small in dimensional change and reduction in strength due to moisture absorption, and low in blistering during reflow furnace soldering. The present invention relates to a thermoplastic resin composition having excellent moldability.

[0002]

2. Description of the Related Art In general, polyamide resins have excellent mechanical properties such as strength, impact resistance and abrasion resistance, high heat resistance and chemical resistance, and good injection moldability. -Used for various applications such as electrical parts and general mechanical parts. Above all, polyamide 4,6 resins have the highest melting point among aliphatic polyamides and are known as engineering plastics having excellent heat resistance. In addition, polyamide 4,6 resins are excellent in mechanical properties such as tensile strength and bending strength, have a short molding cycle due to high crystallization speed, and have good fluidity and injection moldability due to low melt viscosity. It also has the feature that it is used in a wide range of fields.

[0003] Generally, polyamide has a chemical structure
AST is a material that is difficult to burn due to the nitrogen of the amide group.
In the test according to MD635, it falls into the category of self-extinguishing. However, recently, in order to improve the safety of products used in ordinary households, such as household goods, electrical equipment, building materials, and automobile parts, demands for flame retardancy have increased, and regulations on flame retardancy have also been increasing. It's getting tougher. For this reason, regulations are being taken in each country according to national circumstances, and test methods are being determined.

[0004] The United States is particularly severe, underwriters laboratories.
abbreviation; hereinafter, abbreviated as “UL”. ) Standards specify detailed test methods as well as heat resistance, and contribute to improving the safety of electrical equipment and the like. With respect to the flame retardancy of a synthetic resin composition used for electric equipment and the like, it is often required that the composition pass a V-0 standard in a combustion test according to a UL-94 test method. Examples of the method of making the resin flame-retardant include, in addition to making the resin itself flame-retardant, mixing a non-flammable substance, coating with a non-flammable substance and a flame-retardant substance, and adding a flame retardant. As a method of making a polyamide flame-retardant, a method of adding a flame retardant, specifically, a method of compounding an organic halogen compound, as in many other synthetic resins, is known.

[0005] In recent years, in the field of electric and electronic components, various resin-based electronic component materials (connectors, switches, relays, coil bobbins, etc.) have been surface-mounted (SMT) in accordance with miniaturization of products and improvement in productivity. Accordingly, cases of soldering on a printed circuit board have been increasing. Surface mounting (S
The MT) method is a method of mounting an electronic component on a wiring board. Specifically, the electronic component is placed on a printed wiring board, and cream solder or the like is attached thereto, and then reflow is performed for each board. This is a method of fixing electronic components by melting solder by passing through a heating furnace called a furnace. This is different from the conventional insertion mounting method in which the lead of the electronic component is passed through the through hole of the board and directly soldered (free soldering or wave soldering) to the surface opposite to the surface on which the electronic component is mounted.

[0006] The surface mounting method has various advantages such as an increase in mounting density, the possibility of mounting on both sides, and a reduction in manufacturing cost by increasing efficiency.
In accordance with the recent trend of high performance, low price, light weight, and small size of electronic equipment, soldering method is becoming mainstream. As a method of heating the substrate in the reflow furnace, a heat conduction system in which the substrate is heated by placing the substrate on a heat-resistant belt that moves on the heater, and latent heat of coagulation of a fluorine-based liquid having a boiling point of about 220 ° C. is used. VPS system, hot air convection heat transfer system for forcibly circulating hot air, far-infrared system for heating from above or above both upper and lower surfaces with far-infrared, combining heating by hot air and heating by far-infrared Although there are methods used, in many cases, a far-infrared method and a hot air convection heat transfer method are adopted for reasons such as running costs. In these heating methods, unlike the conventional insertion mounting method, the components to be mounted are also heated to the melting temperature of the solder. Therefore, it is a very severe condition for the resin material used for the electronic component.

In the field of electrical and electronic components represented by connectors, etc., their excellent heat resistance (high deflection temperature under load),
The use of polyamides 4 and 6 is increasing from the viewpoint of moldability (fluidity) and toughness. However, polyamide 4,6
When a surface-mounting electronic component made of is passed through a near-infrared ray, far-infrared ray, or hot air (air) reflow furnace in a moisture absorption state of a certain level or more, there is a problem that blisters (blisters) are generated on the surface. In addition, there is a problem that the dimensions change due to moisture absorption with the fine pitch of connectors and the like. Therefore, improvement of these problems has been demanded.

[0008] As a method for improving the hygroscopicity, the change in dimensions due to the hygroscopicity, and the blister resistance of an electronic component composed of polyamide 4,6 resin, a method of blending an aromatic polyester resin with polyamide 4,6 (Japanese Patent Laid-Open No. -190962, JP-A-3-263461, etc.). However, in this method, although the strength is reduced, the size is changed due to moisture absorption, and the blister resistance is improved, there is a problem that burning occurs when the resin stays during molding. Also, JP-A-3-131655, JP-A-4-202
No. 361 and Japanese Patent Application Laid-Open No. Hei 4-209653 propose a method of blending a modified polyphenylene ether with a polyamide 4,6 resin. But with this method,
The dimensional change and the decrease in strength due to moisture absorption were improved, but the blister resistance was not improved.

Further, Japanese Patent Application Laid-Open No. 4-202358,
JP-A-2-255768 discloses polyamide 4,6.
A method of blending an amorphous copolymerized polyamide with a resin has been proposed, and JP-A-6-299069 and JP-A-7-1990.
102173, JP-A-8-3327,
A method of blending a polyphenylene sulfide (PPS) resin with a polyamide 4,6 resin has been proposed. However, in these methods, the change in size and the decrease in strength due to moisture absorption are improved, but the improvement in moisture absorption and blister resistance is insufficient.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to maintain the mechanical properties of polyamides 4 and 6 while maintaining hygroscopicity and dimensional stability during moisture absorption. It is an object of the present invention to obtain a flame-retardant resin composition having improved moldability and blister resistance and excellent moldability.

[0011]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that by blending an arylene sulfide resin and a higher aliphatic polyamide resin with polyamide 4,6 resin, the dimensional change due to moisture absorption is also improved. And found that the present invention has been made. The flame-retardant resin composition of the present invention,
(A) Polyamide 4,6 resin, (B) polyarylene sulfide resin, (C) higher aliphatic polyamide resin, and (D) flame retardant. The flame-retardant resin composition of the present invention may further contain (E) an inorganic filler.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The polyamide 4,6 resin of the component (A) used in the present invention is a resin obtained from tetramethylenediamine and adipic acid, and is a polytetramethylene adipamide or nylon 4,6 resin. Say. Polyamide 4,6 resins include polytetramethylene adipamide and copolymerized polyamides having polytetramethylene adipamide units as main components.

The monomers used as the copolymerization component include:
There is no particular limitation, and any amide-forming component can be used. Representative examples of the copolymerization component include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminoundecanoic acid, paraaminomethylbenzoic acid, lactams such as ε-caprolactam and ω-lauryl lactam, and hexamethylene. Diamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,
4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, meta-xylylenediamine, para-xylylenediamine, 1,3-bis (aminomethyl)
Cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3-aminomethyl-3,5,5
-Trimethylcyclohexane, bis (3-methyl-4-
Aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, 2,2-bis (aminoprosyl) piperazine, aminoethylpiperazine and other diamines and adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid , Terephthalic acid, isophthalic acid,
2-chloroterephthalic acid, 2-methylterephthalic acid, 5
And dicarboxylic acids such as -methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, and diglycolic acid.

The method for producing polyamides 4 and 6 is arbitrary. For example, the methods described in JP-A-56-149430, JP-A-56-149431, JP-A-58-83029, JP-A-61-43631 and the like can be used. That is, first, a prepolymer having a small number of cyclic end groups is produced under specific conditions and then subjected to solid-phase polymerization under a steam atmosphere, or in a polar organic solvent such as 2-pyrrolidone or N-methylpyrrolidone. By heating, high viscosity polyamide 4,6
Can be prepared. The degree of polymerization of the polyamides 4 and 6 is not particularly limited.
Polyamide 4,6 resin having a relative viscosity at g / dl in the range of 2.0 to 6.0 is preferably used.

The amount of the polyamides 4 and 6 as the component (A) is usually 5 to 90% by weight, preferably 20 to 90% by weight, based on the total amount of the components (A) to (C). If it is less than 5% by weight, the excellent mechanical properties (strength, toughness, etc.) of the polyamide 4,6 resin will be impaired, and if it exceeds 90% by weight, oil resistance and heat aging resistance will be poor.

The polyarylene sulfide resin of the component (B) used in the present invention has the following general formula:

Embedded image (Wherein, Ar represents an aromatic group having 6 or more carbon atoms). Representative examples of the aromatic group include p-phenylene, m-phenylene, 2,6-naphthalene, 4,4′-biphenylene, p, p′-bibenzyl, and nucleus-substituted products thereof.

Among polyphenylene sulfides, which are typical examples of polyarylene sulfide resins, poly-p-
Phenylene sulfide is preferred in terms of heat resistance, moldability, and the like. Here, poly-p-phenylene sulfide has the following structural formula (1):

Embedded image The main component is a structural unit represented by

The poly-p-phenylene sulfide preferably contains at least 70 mol%, more preferably at least 90 mol%, of the structural unit of the p-phenylene nucleus. When the structural unit of the p-phenylene nucleus is less than 70 mol%, the tendency such as lowering of crystallinity and heat resistance is increased, which is not preferable. As the poly-p-phenylene sulfide, any one obtained by any method can be used. Generally, poly-p-phenylene sulfide having a relatively small molecular weight obtained by a production method represented by Japanese Patent Publication No. 45-3368 is used. A polymer and an essentially linear high molecular weight polymer obtained by a production method represented by Japanese Patent Publication No. 52-12240 are used. Japanese Patent Publication No. 45-336
No. 8, the polymer obtained by the method described above, after polymerization, by heating in an oxygen atmosphere, or by adding a crosslinking agent such as peroxide and heating to increase the degree of polymerization and used You can also.

Among the poly-p-phenylene sulfides, those which are essentially linear and have a relatively high molecular weight or those which are obtained by partially cross-linking linear ones are preferably used.
In addition, poly-p-phenylene sulfide contains less than 30 mol% of the repeating units in the following structural formulas (2) to (2).
It can be composed of a repeating unit having (8) or the like.

[0020]

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[0021]

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[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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The melt viscosity of the polyphenylene sulfide is not particularly limited as long as it can be kneaded with the polyamide 4,6 resin and can produce a composite material.
0000 poise (310 ° C, shearing speed 1000sec)
^-1 ) is used. Further, polyphenylene sulfide can be used after being deionized with hot water or treated with an acid such as acetic acid, an epoxy compound, an amino group-containing compound, or the like, for the purpose of improving the compatibility with the polyamide resin.

The addition amount of the polyarylene sulfide resin of the component (B) is usually in the total amount of the components (A) to (C).
It is 5 to 90% by weight, preferably 5 to 75% by weight. 5
If it is less than 90% by weight, the low hygroscopicity is inferior, and if it exceeds 90% by weight, the excellent mechanical properties (strength,
Toughness).

The higher aliphatic polyamide resin (C) used in the present invention is a higher aliphatic polyamide having a ratio of the number of methylene groups to the number of amide groups in the polymer main chain (CH ₂ / NHCO) of 6 to 11. The melting point is less than 200C, preferably 160-190C. As such polyamides, polyamide 11 (nylon 11), polyamide 12 (nylon 12), polyamide 6,9 (nylon 6,9), polyamide 6,10 (nylon 6,1)
0), polyamide 6,12 (nylon 6,12), polyamide 6,13 (nylon 6,13), polyamide 7
(Nylon 7) and the like, and mixtures and copolymers thereof. Of these, polylactams such as polyamide 11 and polyamide 12 are particularly preferable. Ratio (CH ₂ /
When the (NHCO) is less than 6 or more than 11, miscibility with the polyamide 4,6 resin is impaired,
The properties of the composition are impaired.

The relative viscosity of the higher aliphatic polyamide resin (the value obtained by preparing a 0.5% m-cresol solution and measuring at 25 ° C. with an Ostwald viscometer) is preferably 1 to 3.
4, more preferably 1.2 to 3.0. The amount of the higher aliphatic polyamide resin (C) added is from (A) to
It is usually 5 to 90% by weight, preferably 5 to 75% by weight, based on the total amount of the component (C). If it is less than 5% by weight, the low hygroscopicity is poor, and if it exceeds 90% by weight, the excellent mechanical properties (strength, toughness, etc.) of the polyamide 4,6 resin are impaired.
Further, the usage ratio (weight ratio) of component (A) / component (C)
Is preferably 55/45 to 90/10. Within this range, the compatibility is further improved, and the desired performance of the present invention is further improved.

As the flame retardant of the component (D) used in the present invention, any one may be used, and preferably one is selected from the group consisting of brominated polystyrene, brominated polyphenylene ether, and brominated epoxy oligomer. Of the above flame retardants, brominated polystyrene is particularly preferred because of its excellent thermal stability.

The brominated polystyrene used in the present invention is represented by the following general formula:

Embedded image (P is an integer of 1 to 5 and n is an integer of 2 or more). Brominated polystyrene is produced by polymerizing brominated styrene or by brominating polystyrene. The bromine content in the brominated polystyrene is preferably from 40 to 75% by weight, particularly preferably from 50 to 75% by weight.

The brominated polystyrene may optionally contain other copolymerizable monomers. Examples of the copolymerizable monomer include olefin and vinyl, and may include a functional group-containing monomer. Examples of the olefin and vinyl include ethylene, propylene, butadiene, butene, hexene, pentene, methylbutene, methylpentene, styrene, acrylonitrile, vinyl chloride, and vinyl acetate.
Butadiene, styrene and acrylonitrile are preferred.

The functional group which may be contained in the copolymerizable monomer is, for example, one or more functional groups selected from a carboxyl group, an acid anhydride group, an oxazoline group and an epoxy group. Specific examples include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic anhydride, vinyl oxazoline, glycidyl methacrylate, and allyl glycidyl ether. Alternatively, the above-mentioned functional group may be copolymerized with brominated styrene, or may be modified at the end of brominated polystyrene or the like.

The weight average molecular weight (M _w ) was determined by gel permeation chromatography (GPC).
Using tetrahydrofuran (THF) as a solvent, the flame retardant was dissolved at a concentration of 1 mg / ml, and the flow rate was 1.0 ml / ml.
The weight average molecular weight in terms of polystyrene can be obtained by measuring the temperature at a temperature of 36 to 40 ° C. Although the weight average molecular weight of the brominated polystyrene of the present invention is not particularly limited, it is preferably 5,000 to 500,000, and particularly preferably 10,000 to 300,000.

The following are examples of flame retardants. D-1: Polybrominated styrene, bromine content 61% by weight Number average molecular weight Mn = 21,000, polymer of dibromostyrene D-2: Polybrominated styrene, bromine content 68% by weight Number average molecular weight Mn = 30 000, Mw / Mn = 2.1
3, copolymer of dibromostyrene: tribromostyrene = 2: 8 D-3: modified polybrominated styrene, bromine content 60% by weight, number average molecular weight Mn = 52,000, Mw / Mn =
1.92, copolymer of maleic anhydride (2% by weight) and dibromostyrene D-4: post-brominated polystyrene, bromine content 67% by weight, number average molecular weight Mn = 84,000, Mw / Mn =
2.39 D-5: post-brominated polystyrene, bromine content 58% by weight, number average molecular weight Mn = 32,000, Mw / Mn =
6.12 D-6: post-brominated polystyrene, bromine content 59% by weight, number average molecular weight Mn = 120,000, Mw / Mn =
3.30

Preferred flame retardants are the above-mentioned polybrominated styrenes such as D-1, 2, 3 and the like obtained by polymerizing brominated styrene. By using these, the effects of the present invention can be further enhanced. . The amount of the flame retardant (D) added is
It is usually 5 to 70 parts by weight, preferably 10 to 60 parts by weight, based on 100 parts by weight of the total amount of the components (A) to (C). If it is less than 5 parts by weight, the flame retardancy is poor, and if it exceeds 70 parts by weight, the excellent mechanical properties (strength, toughness, etc.) of the polyamide 4,6 resin are impaired.

The flame retardant auxiliary used as required in the present invention functions to enhance the flame retardancy of the polyamide 4,6 resin by a synergistic effect with the flame retardant of the component (D). Examples of such a compound include metal compounds of Group Va of the periodic table and metal compounds such as boron oxide, zirconium oxide, iron oxide, and zinc oxide. Particularly, as the metal compound of Group Va of the periodic table, antimony compounds Is preferred. Examples of the antimony compound include antimony trioxide, antimony pentoxide, and sodium antimonate, and antimony trioxide is particularly preferably used. These flame retardant aids may be used alone or in combination of two or more.

The addition amount of the flame retardant aid is usually 0 to 50 parts by weight, preferably 1 to 30 parts by weight, based on 100 parts by weight of the total of the components (A) to (C). If it exceeds 50 parts by weight, the excellent mechanical properties (strength, toughness, etc.) of the polyamide 4,6 resin will be impaired.

The resin composition of the present invention may further contain an inorganic filler (E). By using an inorganic filler, rigidity and dimensional stability can be further improved. Inorganic fillers are various fillers such as fibrous, powdery, granular, plate-like, needle-like, cloth-like, and mat-like fillers. Typical examples include glass fiber, asbestos fiber, carbon fiber, and graphite. Fiber, calcium carbonate, talc, catalbo, walastenite, silica, alumina,
Silica-alumina, diatomaceous earth, clay, calcined clay, kaolin, mica (fine mica), granular glass, glass flake, glass balloon (hollow glass), gypsum, redwood, metal fiber, titanium dioxide, potassium titanate whisker, boric acid Synthetic and natural mineral whiskers such as aluminum whiskers, magnesium oxide, calcium silicate, asbestos, sodium aluminate, calcium aluminate, aluminum, aluminum oxide, aluminum hydroxide, copper, stainless steel, zinc oxide, metal whiskers, etc. it can.

For the purpose of the present invention, glass fibers, carbon fibers, kaolin, mica, talc and various whiskers are preferred, and glass fibers, kaolin and talc are particularly preferred from the viewpoint of economy. The inorganic filler may be surface-treated as long as the moldability and physical properties of the resin composition of the present invention are not impaired. Among them, those subjected to a surface treatment with a compound (such as a sizing agent) typified by aminosilane, acrylic silane, vinyl, urethane, acrylic urethane and the like are preferably used.

The amount of the inorganic filler (E) added is
Usually, 0 to 200 parts by weight, preferably 2 to 150 parts by weight, based on 100 parts by weight of the total amount of the components (A) to (C),
More preferably, it is 5 to 150 parts by weight. If the amount is less than 2 parts by weight, sufficient effects on rigidity and dimensional stability cannot be obtained. If it exceeds 200 parts by weight, the extrudability of the composition will be significantly deteriorated.

The composition of the present invention contains a copper compound such as copper iodide, an aromatic amine compound,
An antioxidant such as a hindered phenol compound, an organic phosphorus compound, a sulfur compound, or a heat stabilizer can also be added. Also, if necessary, as long as the moldability and physical properties are not impaired, other components such as pigments, dyes, ultraviolet absorbers, weathering agents, lubricants, crystal nucleating agents, release agents, plasticizers, antistatic agents Etc. may be added.

Furthermore, other thermoplastic resins, such as other polyamide resins, polyester resins, polyphenylene ether resins, polycarbonate resins, phenoxy resins, polyethylene and copolymers thereof, polypropylene and copolymers thereof, and polystyrene in small proportions And a copolymer thereof, an acrylic resin, a polyamide elastomer, or the like. In order to obtain the resin composition of the present invention, an arbitrary compounding method can be used. For example, using a batch mixer such as a kneader, a Brabender or a Banbury mixer or a single-screw or twin-screw extruder, a method of simultaneously mixing the components, or, for example, pre-blending a few components in advance by a blender or the like. Alternatively, a method of preliminarily mixing with a kneader or an extruder, mixing the remaining components, and homogenizing the mixture can be used.

[0045]

The present invention will be described below with reference to examples and comparative examples. The components used in Examples 1 to 5 and Comparative Examples 1 to 3 are as follows. Component (A): Polyamide 4,6 resin, STANYL (KS200; 96% sulfuric acid 1 manufactured by DSM, Netherlands)
Relative viscosity at g / dl = 3.0) was used. Component (B): As a polyarylene sulfide resin, polyphenylene sulfide resin (M2 manufactured by Toray Industries, Inc.)
588). Component (C): As a higher aliphatic polyamide resin, polyamide 12 resin (L2101 manufactured by Daicel Huls Co., Ltd.)
Was used. As polyamide 6 in the comparative example, MC-120 manufactured by Kanebo Co., Ltd. was used.

Component (D): Polybrominated styrene (Great Lake Chemical C) as a flame retardant
Corporation, "PDBS-80", bromine content = 59%). And, as a flame retardant aid, antimony trioxide (PATOX- manufactured by Nippon Seiko Co., Ltd.)
C) was used. Component (E): As an inorganic filler, a fibrous filler obtained by treating a glass fiber chopped strand having a fiber diameter of 10 μm and a length of 3 mm with a urethane sizing agent and γ-aminopropyltrimethoxysilane (Asahi Fiberglass ( stock)
CS03JAFT-2A).

A modified ethylene-propylene rubber (m-EPR; T7761P manufactured by JSR Corporation) was used as a component other than the above components, and AC-540A manufactured by Allied Signal was used as a lubricant.

Among the components shown in Table 1 below, the components excluding the inorganic filler (CS03JAFT-2A) as the component (E) were
After mixing uniformly in a tumbler in advance, a screw having a cylinder temperature of 300 to 320 ° C. has a two-stage kneading block, and a φ45 mm biaxial with a feedrob in the middle between the first and second kneading blocks. Using an extruder (Ikegai Iron Works PCM45), the above mixture was supplied from the root of the extruder, and the component (E) was supplied from a feedlot on the way, melt-kneaded while drawing a vacuum, and pelletized. The obtained pellets are injected into an injection molding machine (cylinder temperature: 290 to 320).
C), a predetermined test piece was prepared and subjected to the test. In the experimental example in which the inorganic filler of the component (E) is not used, the step of supplying the component (E) is omitted. Table 2 shows the test results. The conditions of each test are as follows.

11. Water absorption (water absorption rate) Injection molding has an outer dimension of 127 mm long and 12 mm wide.
A sample of 7 mm x 0.8 mm in thickness and 3%
In a thermo-hygrostat adjusted to 5 ° C. and a relative humidity of 90%, an increase in weight after humidity control for up to 240 hours was measured.
Water absorption is calculated as follows: water absorption = (weight after humidity control-weight before humidity control) /
It was calculated by the weight before humidity control. The resin composition was melt-kneaded with a twin-screw extruder in a pelletized state, and the strand take-off property during pelletization was evaluated as follows. ：: good. Δ: The strand can be taken off, but sometimes the strand breaks.

11. Blister resistance The outer dimensions are 127 mm long and 12 mm wide by injection molding.
A sample molded to 7 mm × 0.8 mm thickness is humidified in a thermo-hygrostat adjusted to 35 ° C. and 90% relative humidity for up to 240 hours, and the humidified sample is made of 1.6 mm thick glass. Using a table-top far-infrared reflow furnace fixed to an epoxy substrate and set so that the maximum temperature of the sample surface is 240 ° C. when passing through the preheating section 180 ° C. and the main heating section, with the temperature profile shown in FIG. After passing through, the number of blisters (bulges) generated on the surface of the sample was counted.

A flame test (Vertical Test) was performed using a 1/32 inch thick test piece according to the UL-94 test method of Flame Retardant Underwriters Laboratories, and V-0 or V-2 was determined. Judged. However, in the combustion test, V-0 is a case where there is no molten dripping of the resin, or a case where there is a molten dripping of the resin but the cotton placed at the bottom is not ignited, and V-2 is a flame. This is the case where the resin placed on the lower side is ignited due to the molten dripping of the resin accompanied by the following.

[0052]

[Table 1]

[0053]

[Table 2]

The compositions of Examples 1 to 5 have smaller water absorption than the compositions of Comparative Examples 1 to 3, and are excellent in all of the pelletized state, blister resistance and flame retardancy.

[0055]

Industrial Applicability The flame-retardant resin composition of the present invention has excellent mechanical properties, low hygroscopicity, small dimensional change and low strength reduction due to moisture absorption, and blisters during soldering in a reflow furnace. Generation of pellets is extremely small, and the pelletization state is excellent.

[Brief description of the drawings]

FIG. 1 is a diagram showing a temperature profile of a far-infrared reflow furnace in a test for blister resistance.

Claims (2)

[Claims] (A) a polyamide 4,6 resin, and (B)
A flame-retardant resin composition comprising a polyarylene sulfide resin, (C) a higher aliphatic polyamide resin, and (D) a flame retardant. 2. The flame-retardant resin composition according to claim 1, further comprising (E) an inorganic filler.