JPH11100498A - Flame-retardant polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition suppressed in foaming during its melt residence time, improved in moldability, and useful for e.g. heat-resistant containers and microwave oven parts, by compounding magnesium hydroxide and a polyamide resin composed of specific components. SOLUTION: This flame-retardant polyamide resin composition is obtained by compounding (A) pref. 30-70 wt.% of magnesium hydroxide and (B) pref. 70-30 wt.% of a polyamide resin wherein the component B is a copolymer produced from (a) 85-20 mol% of hexamethylenediammonium terephthalate and/or hexamethylenediammounium isophthalate, (b) 0-80 mol% of 21 polyamide-forming monomer such as ω-laurolactam, 12-aminododecanoic acid or 11-aminoundecanoic acid, and (c) 0-80 mol% of a >=16C nylon salt in one salt molecule as, a substantially equimolar salt made from an aliphatic diamine and an aliphatic dicarboxylic acid, with the respective amounts of the components (b) and (c) totaling 15 mol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant polyamide resin composition which is flame-retarded by magnesium hydroxide having excellent mechanical properties, heat resistance, moisture resistance and moldability and which has excellent heat stability. It is. More specifically, the polyamide resin is a polyamide resin containing a semi-aromatic polyamide unit having a specific structure and a higher polyamide unit having an amide group concentration in a specific range, and magnesium hydroxide having excellent heat stability. And a flame-retardant polyamide resin composition.

[0002]

2. Description of the Related Art Polyamide resin has excellent mechanical properties, moldability, oil resistance, solvent resistance, heat resistance, etc.
It is widely used as electronic parts, automobile parts, machine parts and the like. In particular, there is a strong demand for flame retardancy in electric and electronic parts, and it is a necessary condition that the electric component is equivalent to V-0 in the UL standard.

As the flame-retardant polyamide resin, for example, a resin composition in which a halogen-containing flame retardant such as a brominated polystyrene, a brominated polyphenylene ether, a brominated polycarbonate, a brominated epoxy resin, and antimony oxide are blended with a polyamide resin. Widely known. However, a resin composition containing a halogen-based flame retardant and antimony oxide is a resin composition when kneading or molding each component under high-temperature conditions, or when the shear rate at the time of kneading each component is high. Has been decomposed to generate corrosive and toxic gas, which has led to problems such as deterioration of the environment during manufacturing and molding, corrosion of molding machines and molds, and corrosion of terminals in molded products for electric and electronic parts. I have.

In order to solve the problems of these halogen-based flame retardants, non-halogen flame retardants include red phosphorus, melamine cyanurate (MC salt), organic phosphorus compounds (phosphate esters, ammonium polyphosphate salts, etc.), Use of metal hydroxides and the like has been performed.

However, red phosphorus generates a toxic phosphine gas when kneaded with a polyamide resin, and thus has a drawback that the working environment is significantly impaired, and that phosphine causes terminal corrosion in electric and electronic parts. Further, the MC salt has poor heat resistance, and a polyamide resin having a high melting point has a problem that the polyamide is decomposed at the time of compounding. In addition, organic phosphorus compounds have poor thermal stability, so processing conditions are narrow, and they can be applied only to a limited amount of polyamide resin.In addition, they have poor water resistance and low phosphorus content, so they need to be added in large amounts. There are problems such as impairing the characteristic.

[0006] Metal hydroxides are due to heat absorption when the flame retardant mechanism is heated and decomposed to generate water, and have been actively studied in recent years as clean flame retardants without generating toxic or corrosive gases. ing. Aluminum hydroxide and magnesium hydroxide are mainly used as the metal hydroxide, and the thermal decomposition temperature of aluminum hydroxide is as low as 220 ° C.,
Used for thermoplastic resin with low melting point. On the other hand, magnesium hydroxide has a high thermal decomposition temperature of 340 ° C., and flame retardancy of polyolefin and polyamide resins is being studied.

In the composition of polyamide and magnesium hydroxide, the surface of magnesium hydroxide is modified to improve the dispersibility of magnesium hydroxide in the polyamide resin, the adhesion to the polyamide resin, and the mechanical properties. Processing method (JP-A-49-18944, 50-7843)
No., 52-121660, 53-54243, 53
And the method of using a polyolefin in combination (JP-A-49-18944).
JP, JP-A-1-315462, 6-234913
No., 6-240135, 7-5152, 8-208
977) and a method using a thermoplastic aromatic polymer in combination (Japanese Patent Application Laid-Open No. 6-279673).

[0008]

However, it is known that the composition of a normal polyamide resin and magnesium hydroxide undergoes decomposition and foaming during melt retention such as preparation and molding of the composition by a compound, This decomposition foaming could not be suppressed even by using the above-mentioned known technique. As a technique for suppressing the decomposition and foaming, there is disclosed a method of blending an ethylene-vinyl acetate copolymer having good compatibility with polyamide (Japanese Patent Laid-Open No. 52-121660). It was not enough.
Accordingly, an object of the present invention is to provide a polyamide resin composition using magnesium hydroxide as a flame retardant, which does not have the above-mentioned disadvantages of the known art.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a semi-aromatic polyamide unit having a specific structure and a higher polyamide having an amide group concentration in a specific range. It has been found that by including the unit, foaming at the time of melt retention can be suppressed and moldability can be improved,
The present invention has been made.

That is, the flame retardant polyamide resin composition of the present invention is a polyamide resin composition flame retarded by magnesium hydroxide, wherein the polyamide resin comprises (a)
Hexamethylene diammonium terephthalate and / or
Or 85 to 20 mol% of a hexamethylene diammonium isophthalate component, (b) ω-laurolactam, 12
0-80 mol% of at least one polyamide-forming monomer component selected from -aminododecanoic acid and 11-aminoundecanoic acid, and (c) a substantially equimolar salt of an aliphatic diamine and an aliphatic dicarboxylic acid, And a copolymer obtained from 0 to 80 mol% of a nylon salt having 16 or more carbon atoms in one molecule of the salt (wherein component (b) and component (c)
(The total amount of the components is at least 15 mol%).

[0011]

DETAILED DESCRIPTION OF THE INVENTION The hexamethylene diammonium terephthalate component (a) constituting the polyamide resin of the present invention is an equimolar salt composed of hexamethylene diamine and terephthalic acid, and the hexamethylene diammonium isophthalate component is hexamethylene diammonium isophthalate. It is an equimolar salt composed of methylenediamine and isophthalic acid. The component (b) is ω
-Laurolactam, 12-aminododecanoic acid, 11-aminoundecanoic acid, at least one polyamide-forming monomer component, and component (c) is a substantially equimolar salt of an aliphatic diamine and an aliphatic dicarboxylic acid. ,
And a nylon salt having 16 or more carbon atoms in one molecule of the salt.

Specific examples of the component (c) include hexamethylene diammonium sebacate, hexamethylene diammonium decanoate, hexamethylene diammonium dodecanoate and the like.

The raw material components (a) to (c) are 85 to 20 mol%, 0 to 80 mol%, and 0 to 80 mol%, respectively, and the components (b) and (c) are The total amount must be at least 15 mol%. If the component (a) exceeds 85 mol%, the melting point of the obtained polyamide resin is too high, and the moldability decreases. If the content of the component (a) is less than 20 mol%, the obtained polyamide resin has a low melting point and insufficient heat resistance. The melting point of the polyamide resin used in the present invention is preferably in the range of 250 ° C. to 320 ° C., for which (a) to (c)
It is more preferable that the raw material components are 85 to 40 mol%, 0 to 60 mol%, and 0 to 60 mol%, respectively, and the total amount of the component (b) and the component (c) is 20 mol% or more. .

Although the degree of polymerization of the polyamide resin of the present invention is not particularly limited, the relative viscosity measured at 25 ° C. in a 1% strength 98% sulfuric acid solution from the viewpoint of mechanical properties and moldability, etc. Usually, it is 1.5-5.0, preferably 1.8-3.5, particularly preferably 2.0-2.8.

The method for producing the polyamide resin of the present invention is not particularly limited, but may be a conventional pressure melt polymerization, for example, hexamethylene diammonium terephthalate (6T
Salt), a mixed aqueous solution of 12-aminododecanoic acid and / or hexamethylenediammonium sebacate (610 salt) is heated and reacted under a steam pressure of 15 to 40 kg / cm ² , and then melt polymerization is performed while releasing water in the system. The conventional melt polymerization method of performing
Once a prepolymer is produced at 320 ° C., a method of solid-state polymerization at a temperature lower than the melting point or a method of increasing the degree of polymerization with a melt extruder is mentioned. Among them, the pressure melt polymerization method is simple and suitable. I have.

The magnesium hydroxide used in the present invention is generally commercially available, and is not particularly limited in particle size, specific surface area, shape, etc., but preferably has a particle size of 0.1 to 20 μm and a specific surface area. 3 to 75 m ² / g, and the shape is preferably spherical, needle-like or plate-like. The surface treatment of magnesium hydroxide may or may not be performed. Examples of surface treatment methods include silane coupling agents,
A treatment method such as formation of a coating with a thermosetting resin such as an anionic surfactant, a polyfunctional organic acid, or an epoxy resin may be used.

The amount of magnesium hydroxide added is an amount effective for improving the flame retardancy of the composition.
-70% by weight is preferred, more preferably 35-65% by weight.
% By weight. If the amount of magnesium hydroxide is less than 30% by weight, the flame retardancy is impaired, which is not preferable.
Addition of more than 70% by weight does not change the flame retardant effect, but rather impairs the mechanical properties of the composition.

The modified polyolefin used in the present invention is a polyolefin containing a functional group having an affinity for a polyamide resin in a molecular chain, and the functional group includes a carboxylic acid group, a carboxylic anhydride group, and a carboxylic acid group. An α-olefin homopolymer or copolymer containing at least one selected from an ester group, a carboxylic acid metal base, a carboxylic acid imide group, and a carboxylic acid amide group in a polymer molecular chain, or a diene elastomer is preferable.

Specific examples of the α-olefin homopolymer or copolymer include homopolymers such as polyethylene, polypropylene, poly (1-butene), poly (1-pentene), and polymethylpentene; ethylene, propylene; Butene, 1-pentene, 4-methyl-1-
Α-olefins such as pentene and isobutylene and 1,4
At least one non-conjugated diene such as hexadiene, dicyclopentadiene, 2,5-norbornadiene, 5-ethylidene norbornene, 5-ethyl-2,5-norbornadiene, 5- (1′-propenyl) -2-norbornene; Copolymers obtained by radical polymerization can be mentioned.

The diene elastomer is 1,4-
It is an AB- or ABA'-type block copolymer elastic body composed of a homopolymer of a diene such as butadiene and a hydrogenated product thereof, or a vinyl aromatic hydrocarbon and a conjugated diene. End blocks A and A ′ in block copolymer elastic body
May be the same or different, and include a thermoplastic homopolymer or copolymer derived from a vinyl aromatic hydrocarbon in which the aromatic portion may be monocyclic or polycyclic. Examples of such vinyl aromatic hydrocarbons include styrene α-methylstyrene, vinyl toluene, vinyl xylene, ethyl vinyl xylene, vinyl naphthalene, and mixtures thereof. The intermediate polymer block B is made of a conjugated diene hydrocarbon, for example, 1,3-butadiene,
Examples include polymers derived from 2,3-dimethylbutadiene, isoprene, 1,3-pentadiene, and mixtures thereof. In the present invention, the intermediate copolymer block B of the above-mentioned block copolymer may be subjected to a hydrogenation (simply hydrogenation) treatment.

Specific examples of the polyolefin copolymer include ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / propylene / dicyclopentadiene copolymer, and ethylene / propylene / 5-ethylidene-2-norbornene copolymer. Examples thereof include unified, unhydrogenated or hydrogenated polybutadiene, unhydrogenated or hydrogenated styrene / isoprene / styrene triblock copolymer, and unhydrogenated or hydrogenated styrene / butadiene / styrene triblock copolymer.

Specific examples of the functional group-containing component that modifies the polyolefin include acrylic acid, methacrylic acid,
Maleic acid, fumaric acid, itaconic acid, crotonic acid, methyl maleic acid, methyl fumaric acid, mesaconic acid, citraconic acid, glutaconic acid, and metal salts of these carboxylic acids, methyl hydrogen maleate, methyl hydrogen itaconate, methyl acrylate, Ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 2-ethylhexyl methacrylate, hydroxyethyl methacrylate, aminoethyl methacrylate, dimethyl maleate, dimethyl itaconate, maleic anhydride , Itaconic anhydride, citraconic anhydride, endobicyclo- [2.2.1] -5-heptene-2,3-dicarboxylic acid, endobicyclo- [2.
2.1] -5-heptene-2,3-dicarboxylic anhydride, maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenylmaleimide, glycidyl acrylate, glycidyl itaconate, glycidyl citraconic acid. The method for introducing these functional group-containing components is not particularly limited, and a method such as copolymerization or introduction into an unmodified polyolefin using a radical initiator can be used. The amount of the functional group-containing component to be introduced is suitably in the range of 0.001 to 40 mol%, preferably 0.01 to 35 mol%, based on the whole modified polyolefin.

Specific examples of the modified polyolefin used in the present invention include maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer and carboxylic acid in these copolymers. Some or all of the acid moiety is a metal salt with sodium, lithium, potassium, zinc, calcium, etc., ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene /
Methyl methacrylate copolymer, ethylene / ethyl methacrylate copolymer, ethylene / ethyl acrylate-g-maleic anhydride copolymer ("g" represents a graft, the same applies hereinafter), ethylene / methyl methacrylate-g -Maleic anhydride copolymer, ethylene / ethyl acrylate-g-
Maleimide copolymer ethylene / ethyl acrylate-g-
N-phenylmaleimide copolymer and partially saponified products of these copolymers, ethylene / glycidyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl methacrylate copolymer, ethylene / methyl methacrylate / glycidyl methacrylate copolymer, ethylene / Glycidyl acrylate copolymer, ethylene / vinyl acetate / glycidyl acrylate copolymer, ethylene / glycidyl ether copolymer, ethylene / propylene-g
-Maleic anhydride copolymer, ethylene / 1-butene-g
-Maleic anhydride copolymer, ethylene / propylene /
1,4-hexadiene-g-maleic anhydride copolymer,
Ethylene / propylene / dicyclopentadiene-g-maleic anhydride copolymer, ethylene / propylene / 2,5
-Norbornadiene-g-maleic anhydride copolymer ethylene / propylene-g-N-phenylmaleimide copolymer, ethylene / butene-1-g-N-phenylmaleimide copolymer, hydrogenated styrene / butadiene / styrene-g
-Maleic anhydride copolymer, hydrogenated styrene / isoprene / styrene-g-maleic anhydride copolymer, ethylene /
Propylene-g-glycidyl methacrylate copolymer, ethylene / 1-butene-g-glycidyl methacrylate copolymer, ethylene / propylene / 1,4-hexadiene-
Examples include g-glycidyl methacrylate copolymer, ethylene / propylene / dicyclopentadiene-g-glycidyl methacrylate copolymer, hydrogenated styrene / butadiene / styrene-g-glycidyl methacrylate copolymer, and the like.

Among these modified polyolefins, maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, ethylene / acrylic acid copolymer and part of the carboxylic acid moiety in ethylene / methacrylic acid copolymer are particularly preferable. All of which are salts with sodium, lithium, potassium, zinc, and calcium, ethylene / ethyl acrylate-g-maleic anhydride copolymer, ethylene / methyl methacrylate-g-maleic anhydride copolymer and copolymers thereof. Partially saponified polymer; ethylene / glycidyl methacrylate copolymer, ethylene /
Methyl methacrylate / glycidyl methacrylate copolymer, ethylene / glycidyl acrylate copolymer, ethylene / glycidyl ether copolymer, ethylene / propylene-g-maleic anhydride copolymer, ethylene / 1-butene-g-maleic anhydride Copolymer, ethylene / propylene / 1,4-hexadiene-g-maleic anhydride copolymer, hydrogenated styrene / butadiene / styrene-g-maleic anhydride copolymer, hydrogenated styrene / isoprene / styrene-g- Maleic anhydride copolymer, ethylene / propylene-g-glycidyl methacrylate copolymer, ethylene / 1-butene-g-glycidyl methacrylate copolymer,
Examples thereof include ethylene / propylene / 1,4-hexadiene-g-glycidyl methacrylate copolymer and hydrogenated styrene / butadiene / styrene-g-glycidyl methacrylate copolymer. The amount added is 0 to 15 parts by weight based on 100 parts by weight of the composition of magnesium hydroxide and the polyamide resin. If the amount exceeds 15 parts by weight, the flame retardancy is impaired, which is not preferred.

A filler may be added to the composition of the present invention to improve the strength. In such a case, a fibrous filler is preferable. The fibrous filler may be any commonly used fibrous filler. Specific examples include glass fiber, carbon fiber, aramid fiber,
Potassium titanate fiber, metal fiber, ceramic fiber and the like can be mentioned. These fillers may be used alone or in combination of two or more.

Glass fibers are preferably used among the above-mentioned fibrous reinforcing materials. The type of glass fiber is not particularly limited as long as it is used for general resin reinforcement. For example, it can be selected from long fiber type or single fiber type chopped strand, milled fiber and the like. The fiber diameter is not limited, but a fiber diameter of 6 to 20 μm is preferably used. These glass fibers are ethylene /
It may be coated or bundled with a vinyl acetate copolymer or a thermosetting resin, or may be treated with a silane-based, titanate-based coupling agent, or another surface treatment agent. The amount of the fibrous reinforcing material is not particularly limited, but is preferably 10 to 50 parts by weight based on 100 parts by weight of the composition of magnesium hydroxide and the polyamide resin. If the amount is less than 10 parts by weight, the effect of strengthening is insufficient.
If the amount is more than 0 parts by weight, the mechanical properties inherent in the polyamide resin are impaired, which is not preferable.

The polyamide resin composition of the present invention may contain additives, for example, a flame retardant other than magnesium hydroxide (brominated polyphenylene oxide (Br-PPO), which is a halogen-based flame retardant), or brominated, as long as its properties are not impaired. Melamine cyanurate, which is a triazine-based flame retardant, such as polystyrene (Br-PSt), poly (2-brominated styrene), and brominated polycarbonate (Br-PC); Melamine, cyanuric acid, and other phosphates, and flame retardants (fluororesins represented by polytetrafluoroethylene (PTFE), silicone resins, phenol novolak resins, polyalkyl acrylate rubbers, polyetherimides (PEI) , Polyphenylene sulfide Resins such as PPS), polyimide (PI), polyarylate, polyphenylene ether (PPE), borates, metal oxides (eg, aluminum oxide, magnesium oxide, zinc oxide, tin oxide, silicon oxide, antimony oxide, calcium oxide, Iron oxide),
Heat stabilizers (hindered phenols, hydroquinones, phosphites and their substitutes, copper iodide,
Potassium iodide, etc.), weathering stabilizers (resorcinol, salicylate, benzotriazole, benzophenone, hindered amine, etc.), release agents and lubricants (montanic acid and its salts, esters, half esters, stearyl alcohol) , Stearamide and polyethylene wax, etc.), pigments (cadmium sulfide, phthalocyanine, carbon black, etc.) and dyes (eg, nigrosine), fillers (glass beads, talc, kaolin, wollastonite, mica, silica, diatomaceous earth, clay, stone) Plasticizers, lubricants, nucleating agents, and the like, such as ko, bengara, and graphite, may be added.
These additives may be used in a mixture. The amount of the additive can be selected according to the purpose of each additive.

The flame-retardant polyamide resin composition of the present invention is used for electric / electronic-related parts such as heat-resistant containers, microwave oven parts, rice cooker parts, automobile / vehicle-related parts, household /
It is effective for office electrical product parts, computer related parts, facsimile / copier related parts, machine related parts, and various other uses.

[0029]

The present invention will be described in more detail with reference to the following Examples, which, however, are not intended to restrict the scope of the present invention. Various properties in the examples and comparative examples were measured by the following methods.

(1) Melt retention stability (visual) Melt viscosity measuring device: Melt indexer (manufactured by Toyo Seiki Seisaku-sho, Ltd .: TYPE C-5059D2) melts and retains at the molding condition temperature for 5 minutes to determine the surface condition of the extruded polymer. Visual observation was made to confirm the presence or absence of foaming. The case where no foaming occurred was evaluated as ““ ”, and the case where foaming was performed was evaluated as“ × ”.

(2) Mechanical properties Tensile strength, elongation: Measured according to ASTM D638. B. Flexural modulus: measured according to ASTM D760. (3) Flammability: Measured using a test piece having a thickness of 1/16 inch according to the method of UL94.

[Preparation of Polyamides A to G] Polyamides having the compositions shown in Table 1 were prepared. Below, polyamide A,
A method for preparing polyamide A is shown as a typical example in the case of C, D and E, and a method for preparing polyamide F as a typical example in the case of polyamides B, F and G. In the case of other polyamides, the composition is changed. It was prepared according to those methods.

(Method for Preparing Polyamide A)
In a L polymerization vessel, hexamethylenediamine 65% by weight aqueous solution: 5.019 kg (28.1 mol), terephthalic acid:
4.676 kg (28.1 mol), 12-aminododecanoic acid: 6.056 kg (28.1 mol), benzoic acid: 8
After charging 5.9 g and 7.582 kg of water and replacing with nitrogen, the mixture was heated and heated (when the internal temperature reached 170 ° C., the stirrer was started). Pressure is 17.5kg / c
When the internal pressure reached m ² G (gauge pressure), the pressure was adjusted to a constant value. After the internal temperature reached 280 ° C., the pressure was gradually reduced to 0 kg / cm ² over 2 hours. The polymer temperature of the contents was 310 ° C. The pressure in the polymerization vessel was increased to 10 kg / cm ² with nitrogen, the gear pump at the bottom of the polymerization vessel was driven to discharge the polymer, and cooled through a cooling bath.
The strand was pelletized by a cutter. After vacuum drying the pellets at 110 ° C. for 12 hours, the melting point was measured, and the results shown in Table 1 were obtained.

(Method for Preparing Polyamide F)
6.966 kg of a 65% by weight aqueous solution of hexamethylenediamine, 6.023 kg of terephthalic acid,
Isophthalic acid: 1.390 kg, 12-aminododecanoic acid: 2.402 kg, benzoic acid: 54.44 g, water:
After charging 7.22 kg and sodium hypophosphite: 6.59 g and purging with nitrogen, the mixture was heated and heated (internal temperature was 170).
When the temperature reached ° C, the stirrer was started). Pressure is 35k
g / cm ² G (gauge pressure), the pressure was adjusted to a constant value, and after the internal temperature reached 310 ° C., steam was supplied from the top of the polymerization vessel, and the oligomer was discharged from the bottom of the polymerization vessel while maintaining the pressure. Cooled and solidified. The solidified oligomer was dried with a vacuum drier and then pulverized with a pulverizer. The pulverized oligomer is supplied to a twin screw extruder (Nippon Steel Works TEX30).
XSSST) to obtain a high degree of polymerization by melt extrusion at 330 ° C., and pelletized with a pelletizer. The relative viscosity of the oligomer (measured in a 1% sulfuric acid solution at 25 ° C.) is 1.3.
4, The relative viscosity of the polymer after increasing the degree of polymerization was 2.50. After vacuum drying the pellets at 110 ° C for 12 hours,
The melting point was measured and the results shown in Table 1 were obtained.

Examples 1 to 6 Polyamide A shown in Table 1
~ D, F, and G, and dry-blended with magnesium hydroxide in the composition shown in Table 2, followed by a twin-screw extruder [Ikegai Co., Ltd.
PCM30] to obtain pellets of the composition. The pellets were vacuum-dried at 110 ° C. for 12 hours and then molded to evaluate the properties of the composition. The results in Table 2 were obtained. The composition obtained was a test piece having a thickness of 1/16 inch according to the UL-94 evaluation method and was excellent in V-0 and flame retardancy. Furthermore, there was no resin sagging or blowing due to foaming of the material at the time of molding, and there was no foaming at the time of melt retention, and the thermal stability was excellent.

Comparative Example 1 Using polyamide E shown in Table 1, dry blending with magnesium hydroxide in the composition shown in Table 2, followed by melt-kneading with a twin-screw extruder [PCM30 manufactured by Ikegai Co., Ltd.] Was obtained. The pellet was a pellet containing bubbles due to foaming during extrusion. After vacuum drying the pellets at 110 ° C. for 12 hours, the pellets were molded and the properties of the composition were evaluated. The results shown in Table 2 were obtained. This composition was a composition in which the resin flowed out from the nozzle of the molding machine during molding while foaming, and the melt retention stability was poor. V-0 was not obtained due to the effect of foaming on flammability.

[0037]

[Table 1]

[0038]

[Table 2]

[Examples 7 to 10] Glass fibers having the composition shown in Table 3 were further added to the blends of Examples 1 to 4 in Table 2, and the three components were dry blended. Ikegai Co., Ltd. PCM30] to obtain a pellet of the composition. After vacuum drying the pellets at 110 ° C. for 12 hours, they were molded and the properties of the composition were evaluated. The results shown in Table 3 were obtained. The resulting composition exhibited a flammability of V-0 on a 1/16 inch thick test piece, and was excellent in thermal stability and flame retardancy.

Comparative Example 2 The formulation of Comparative Example 1 in Table 2
Further, glass fibers were added in the composition shown in Table 3, the three components were dry-blended, pelletized and dried in the same manner as in Example 5, and then molded to evaluate the characteristics of the composition. As shown in Table 2, both flame retardancy and thermal stability were poor.

[Examples 11 to 15] Examples 1 and 3 in Table 2
Further, glass fibers and a modified polyolefin having the composition shown in Table 3 were added to the blends of Nos. To 6, and the four components were dry-blended, and then a twin-screw extruder [PCM30 manufactured by Ikegai Co., Ltd.]
To obtain a pellet of the composition. 1 pellet
After vacuum drying at 10 ° C. for 12 hours, the composition was molded and the characteristics of the composition were evaluated. The results shown in Table 3 were obtained. The resulting composition exhibited a flammability of V-0 on a 1/16 inch thick test piece, and was excellent in thermal stability and flame retardancy.

Comparative Example 3 The formulation of Comparative Example 1 in Table 2
Further, glass fibers and a modified polyolefin were added in the composition shown in Table 3, and the four components were dry-blended and then processed and evaluated in the same manner as in Example 11. As shown in Table 3, the flame retardancy was also high. The stability was also poor.

[0043]

[Table 3]

[0044]

According to the present invention, a semi-aromatic polyamide resin having a specific structure becomes a flame-retardant polyamide resin composition having good thermal stability even if it is made flame-retardant with Mg (OH) ^2, which is extremely alkaline. The decomposition foaming at the time of melt retention generated at the time of preparation or molding can be suppressed, and the moldability can be further improved.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 23:26)

Claims (6)

[Claims] 1. A polyamide resin composition flame-retarded by magnesium hydroxide, wherein the polyamide resin comprises:
(A) 85 to 20 mol% of a hexamethylene diammonium terephthalate and / or hexamethylene diammonium isophthalate component, and (b) at least one selected from ω-laurolactam, 12-aminododecanoic acid, and 11-aminoundecanoic acid. From 0 to 80 mol% of various polyamide-forming monomer components, and (c) a substantially equimolar salt and salt of an aliphatic diamine and an aliphatic dicarboxylic acid.
Nylon salts 0 to 8 having 16 or more carbon atoms in the molecule
A flame-retardant polyamide resin composition, which is a copolymer obtained from 0 mol% (provided that the total amount of the components (b) and (c) is at least 15 mol%). 2. The flame-retardant polyamide resin composition according to claim 1, wherein magnesium hydroxide is contained in an amount of 30 to 70% by weight and polyamide resin is added in an amount of 70 to 30% by weight. 3. A polyamide resin having a melting point of not lower than 250 ° C.
The flame-retardant polyamide resin composition according to claim 1, wherein the temperature is lower than 20 ° C. 4. 4. The flame-retardant polyamide resin according to claim 1, wherein the equimolar salt of the aliphatic diamine and the aliphatic dicarboxylic acid as the component (c) in the polyamide resin is hexamethylene diammonium sebacate. Composition. 5. The magnesium hydroxide has a specific surface area of 3-7.
Having 5 m ² / g, spherical, needle-like or platelet-shaped flame-retardant polyamide resin composition according to any one of claims 1 to 4 having a particle shape. 6. A modified polyolefin of 0 to 100 parts by weight in total of magnesium hydroxide and a polyamide resin.
The flame-retardant polyamide resin composition according to any one of claims 1 to 5, comprising 15 parts by weight and 10 to 50 parts by weight of a fibrous filler.