JP2000044796A - Flame-retardant polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compsn. having excellent mechanical characteristics, heat resistance, moldability, and dimensional stability, and also a small change in the toughness deterioration and in the dimension at the time of water absorption. SOLUTION: A resin compsn. comprises 100 pts.wt. of component (A) of a polyamide resin which consists of 75-45 mole % of (a) hexamethylene terephthalamide unit, 10-25 mole % of (b) hexamethylene terephthalamide and/or hexamethylene hexahydro-terephthalamide units and 15-30 mole % of (c) an aliphatic polyamide unit having the number of carbon atoms per one amide group (amide group concn.) of 8 or more and which has the properties within the range described below and 0.1-50 pts.wt. of component (B) of a nonhalogen- based flame retardant. (1) an m.p.: not lower than 280 deg.C to lower than 325 deg.C. (2) a glass transition point at the time of satd. water absorption which is determined by a viscoelastic measurement, of 40 deg.C or above, and also a loss elastic modulus having at least one peak of plurally observed ones, at 80 deg.C or above.

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 having excellent mechanical properties, heat stability, moisture resistance, and moldability, and particularly excellent heat resistance and dimensional stability. The flame-retardant polyamide resin composition of the present invention is suitable, for example, as a molding material for industrial materials, industrial materials, electric / electronic materials, particularly, surface mount substrates requiring solder heat resistance.

[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 a method of imparting flame retardancy to a thermoplastic resin, a method of compounding a resin with a halogen-based organic compound as a flame retardant and a metal oxide such as an antimony compound as a flame retardant aid is generally used. is there. However, this method tends to generate a large amount of smoke during combustion. Further, a resin composition containing a halogen-based flame retardant has a problem that electrical properties such as tracking resistance are deteriorated. Therefore, in recent years, it has been strongly desired to use a flame retardant containing no halogen at all.

Heretofore, as a method of making a thermoplastic resin flame-retardant without using a halogen-based flame retardant, it is widely known to add a hydrated metal compound such as aluminum hydroxide or magnesium hydroxide. In order to obtain sufficient flame retardancy, it is necessary to add a large amount of the above-mentioned hydrated metal compound, which has a disadvantage that the inherent properties of the resin are lost.

On the other hand, as a method for making a polyamide resin flame-retardant without using such a hydrated metal compound, the addition of red phosphorus is disclosed in JP-A-60-168775 and JP-A-6-16857.
JP-A-219706, JP-A-63-89567, JP-A-1-129061, JP-A-2-169
666, JP-A-3-197553, JP-A-6-145504, JP-A-6-263983, and the like.

[0006]

However, the flame-retardant polyamide resin composition manufactured by the prior art using nylon 6, nylon 66, etc., which are widely used as the polyamide resin of the prior art, is not heat-resistant. As a material for a surface-mount substrate that requires heat resistance, the heat resistance is insufficient and the characteristics are insufficient.The flame-retardant polyamide resin composition of nylon 46 has high heat resistance but high water absorption and dimensional stability There is a drawback such as lack of properties, and the emergence of a flame-retardant polyamide resin composition having both heat resistance and dimensional stability has been strongly desired. Therefore, an object of the present invention is to obtain a flame-retardant polyamide resin composition having excellent mechanical properties, moldability, and dimensional stability, and particularly excellent in heat resistance and having a small dimensional change upon water absorption.

[0007]

That is, the present invention relates to (1) a method wherein "(A) the polyamide resin comprises (a) 75 to 45 mol% of hexamethylene terephthalamide units,
(B) hexamethylene isophthalamide and / or hexamethylene hexahydroterephthalamide unit 10
(C) a polyamide comprising 15 to 30 mol% of an aliphatic polyamide unit having 8 or more carbon atoms per one amide group (amide group concentration), and further having the following characteristics: 100 parts by weight of resin and (B)
A flame-retardant polyamide resin composition comprising 0.1 to 50 parts by weight of a non-halogen flame retardant. (A) Melting point: 280 ° C. or more and less than 325 ° C. (b) Glass transition point at saturated water absorption determined by viscoelasticity measurement of 40 ° C. or more At 80 ° C
(2) "The flame-retardant polyamide resin composition according to the above (1), wherein the aliphatic polyamide unit of the component (c) is undecaneamide or dodecaneamide.", (3)
"The flame-retardant polyamide resin composition according to the above (2), wherein the polyamide unit of the component (c) is a dodecaneamide unit.", (4) "The polyamide resin of the component (A) has a melting point in the range of 300 to 325C. The flame-retardant polyamide resin composition according to any one of (1) to (3) above. "
(5) "The flame-retardant polyamide resin composition according to any one of the above (1) to (4), wherein the non-halogen flame retardant of the component (B) is a phosphorus-containing flame retardant." The flame-retardant polyamide resin composition according to the above (5), wherein the non-halogen flame retardant of the component (B) is red phosphorus. ", (7)" The non-halogen flame retardant of the component (B) is a thermosetting resin. The flame-retardant polyamide resin composition according to the above (6), which is red phosphorus coated with:
(8) The flame-retardant polyamide resin composition according to any one of the above (1) to (7), further comprising (C) 0 to 150 parts by weight of an inorganic filler based on 100 parts by weight of the polyamide resin. (9) "The flame-retardant polyamide resin composition according to the above (8), wherein the inorganic filler of the component (C) is a fibrous reinforcing material.", (10) "The fibrous reinforcing material is glass fiber. The flame-retardant polyamide resin composition according to the above (9). ",
(11) “(D) based on 100 parts by weight of polyamide resin
The flame-retardant polyamide resin composition according to any one of the above (1) to (10), further comprising 0.1 to 50 parts by weight of a polyethylene terephthalate resin. (12) "(1) wherein the polyamide resin further contains 0.01 to 10 parts by weight of (E) a fluorine-based resin based on 100 parts by weight of the polyamide resin
The flame-retardant polyamide resin composition according to any one of (11) to (11). (13) A molded article obtained by injection-molding the flame-retardant polyamide resin composition according to any one of (1) to (12) above.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The polyamide resin used as the component (A) in the present invention comprises (a) hexamethylene terephthalamide unit, (b) hexamethylene isophthalamide and / or hexamethylene hexahydroterephthalamide unit, and c) A polyamide resin containing a structural unit derived from an aliphatic polyamide unit having 8 or more carbon atoms (amide group concentration) per amide group as an essential component.

The hexamethylene terephthalamide unit of the component (a) is a unit synthesized from a derivative of hexamethylene diamine and terephthalic acid or an ester or acid halide thereof. The hexamethylene isophthalamide unit of the component (b) is a unit synthesized from hexamethylene diamine and a derivative of isophthalic acid or an ester or acid halide thereof. The hexamethylene hexahydroterephthalamide unit is a hexamethylene isophthalamide unit. It is a unit synthesized from methylene diamine and derivatives such as 1,4-cyclohexanedicarboxylic acid or its ester and acid halide. 1,4-cyclohexanedicarboxylic acid has cis-trans isomerism. Is not limited.

Specific examples of the raw material for providing an aliphatic polyamide unit having 8 or more carbon atoms (amide group concentration) per amide group of component (c) include hexamethylene diammonium sebacate and hexamethylene diammonium sebacate. Methylene diammonium decanoate, hexamethylene diammonium dodecanoate, 12-aminododecanoic acid, ω-laurolactam, units derived from raw materials such as 11-aminoundecanoic acid can be mentioned, and particularly preferably, It is a unit derived from a raw material such as ω-laurolactam and 12-aminododecanoic acid.

These polyamide constituents are represented by (a) to
(C) a copolymer containing 75 to 45 mol%, 10 to 25 mol%, and 15 to 30 mol% of the respective components, and further maintain a glass transition point of 40 ° C. or higher when absorbing water; It is necessary and important in the present invention that there is a segment having a loss elastic modulus peak of 80 ° C. or higher. This is because the copolymerized polyamide obtained by polymerizing the above-mentioned specific copolymerization component in an extremely limited copolymerization ratio has a specific melting point, viscoelastic behavior, viscoelastic behavior upon water absorption, and in a high humidity atmosphere. The rigidity is not reduced, and the heat resistance, toughness, moldability, dimensional stability, and high dimensional stability when absorbing water are well balanced. It is.

If the copolymerization amount of the component (a) is larger than the above range, the melting point of the polyamide resin to be formed becomes high, so that the thermal stability is impaired, such as deterioration upon melting, and the moldability is deteriorated. On the contrary, when the amount is smaller than the above range, the rigidity at the time of water absorption is undesirably reduced. Further, the desired melting point cannot be obtained, and the heat resistance is lowered, so that it cannot be used for the intended use. If the copolymerization amount of the component (b) is larger than the above range, the crystallinity is reduced, and moldability such as an injection molding cycle is impaired. It is not preferable because dimensional stability such as increase in the rate is lowered. (C)
If the copolymerization amount of the component is larger than the above range, the melting point is lowered, and the required heat resistance cannot be maintained, which is not preferable.On the contrary, if it is smaller than the above range, the water absorption increases, and the rigidity at the time of water absorption decreases. Is not preferred.

Although the degree of polymerization of the polyamide resin of the present invention is not particularly limited, the relative viscosity of the polyamide resin measured at 25 ° C. in a 1% sulfuric acid solution is usually 1. 5 to 5.0, preferably 1.8 to 3.
5, particularly preferably those in the range of 2.0 to 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), hexamethylene diammonium isophthalate (6I salt) and 12-aminododecanoic acid
Heat reaction under steam pressure of 5-40 kg / cm ² ,
Then, a conventional melt polymerization method in which melt polymerization is performed while releasing water in the system, or a raw material aqueous solution is heated to 250 to 330 ° C.
To form a prepolymer once and then solid-phase polymerize it at a temperature below the melting point, or extrude the prepolymer with a melt extruder to increase the degree of polymerization.

The non-halogen flame retardant which is the component (B) of the present invention is a halogen-free flame retardant. Specifically, a normal phosphorus flame retardant or a nitrogen-based flame retardant may be used. Can be.

The phosphorus-based flame retardant is a compound containing a phosphorus element, and specific examples thereof include red phosphorus, ammonium polyphosphate, an aromatic phosphate compound, and an aromatic bisphosphate compound.

Examples of the nitrogen-based flame retardant include compounds that form a salt of a triazine-based compound with cyanuric acid or isocyanuric acid. The salt of cyanuric acid or isocyanuric acid is an adduct of cyanuric acid or isocyanuric acid with a triazine-based compound, and is usually one-to-one.
(Molar ratio), if necessary, an adduct having a composition of 1: 2 (molar ratio). Of the triazine compounds, those that do not form a salt with cyanuric acid or isocyanuric acid are excluded. Of the salts with cyanuric acid or isocyanuric acid, particularly preferred examples include melamine, mono (hydroxymethyl) melamine, di (hydroxymethyl) melamine, tri (hydroxymethyl) melamine, benzoguanamine, acetoguanamine and 2-amide-4. , 6-diamino-1,3,5-triazine, and melamine, benzoguanamine and acetoguanamine are particularly preferred.

Of these, phosphorus-based flame retardants can be preferably used, and among the phosphorus-based flame retardants, red phosphorus is more preferred, and red phosphorus coated with a thermosetting resin is particularly preferred.

Next, the red phosphorus used in the present invention will be described. The red phosphorus used in the present invention is unstable when used alone, and has the property of gradually dissolving in water or reacting gradually with water. Can be

As a method for treating such red phosphorus, the crushed surface having high reactivity with water and oxygen is formed on the surface of red phosphorus without crushing the red phosphorus described in JP-A-5-229806. Red phosphorus is finely divided into particles, a method of adding a small amount of aluminum hydroxide or magnesium hydroxide to red phosphorus to catalytically suppress oxidation of red phosphorus, coating red phosphorus with paraffin or wax, and Method of suppressing contact, method of stabilizing by mixing with ε-caprolactam and trioxane, stabilization by coating red phosphorus with thermosetting resin such as phenolic, melamine, epoxy, and unsaturated polyester A method of treating red phosphorus with an aqueous solution of a metal salt such as copper, nickel, silver, iron, aluminum and titanium to precipitate and stabilize a metal phosphorus compound on the red phosphorus surface, A method of coating phosphorus with aluminum hydroxide, magnesium hydroxide, titanium hydroxide, zinc hydroxide, etc .; a method of stabilizing by coating an electroless plating with red, phosphorus, iron, cobalt, nickel, manganese, tin, etc. on the surface; and A method combining these may be mentioned.

Preferably, a method of pulverizing the red phosphorus without pulverizing the red phosphorus and forming a crushed surface on the surface of the red phosphorus, a method of converting the red phosphorus into a phenol type, a melamine type, an epoxy type, an unsaturated polyester type, etc. The method of stabilizing by coating with a thermosetting resin of, the method of stabilizing by coating red phosphorus with aluminum hydroxide, magnesium hydroxide, titanium hydroxide, zinc hydroxide and the like, particularly preferably, A method of forming red phosphorus into fine particles without forming a crushed surface on the surface of red phosphorus, and a method of stabilizing red phosphorus by coating it with a thermosetting resin such as a phenolic, melamine, epoxy, or unsaturated polyester. It is. Among these thermosetting resins, red phosphorus coated with a phenolic thermosetting resin or an epoxy thermosetting resin can be preferably used from the viewpoint of moisture resistance, and particularly preferably a phenolic thermosetting resin. Red phosphorus coated with resin.

The average particle size of red phosphorus before being blended with the resin is preferably 50 to 0.01 μm, more preferably, from the viewpoint of flame retardancy, mechanical strength and surface appearance of the molded product. , 45 to 0.1 μm.

The conductivity of the red phosphorus used in the present invention at the time of extraction treatment in hot water (the conductivity is determined by adding 100 mL of pure water to 5 g of red phosphorus, for example, in an autoclave to obtain a conductivity of 12 g).
Extraction treatment was performed at 1 ° C for 100 hours.
Measuring the conductivity of the extracted water diluted to 0 mL), the moisture resistance, mechanical strength, tracking resistance,
0.1 to 1000 μS / cm from the viewpoint of surface properties
And preferably 0.1 to 800 μS / cm, and more preferably 0.1 to 500 μS / cm.

Further, the amount of phosphine generated by the red phosphorus used in the present invention (here, the amount of phosphine generated is determined by placing 5 g of red phosphorus in a container such as a test tube having a capacity of 500 mL in which nitrogen is replaced with nitrogen and reducing the pressure to 10 mmHg. Heat treatment at 280 ° C. for 10 minutes, cool to 25 ° C., dilute the gas in the test tube with nitrogen gas, return to 760 mmHg, measure using a phosphine (hydrogen phosphide) detector tube, and use the following formula Phosphine generation (ppm) = Detector tube indication value (ppm)
X dilution ratio)

The amount of phosphine generated is usually 100 ppm from the viewpoint of the amount of gas generated from the composition obtained, stability during extrusion and molding, mechanical strength during melt retention, surface appearance of molded products, terminal corrosion by molded products, and the like. The following are used, preferably 50 ppm or less, more preferably 20 ppm or less. Specific examples of preferred commercial products of red phosphorus include "NOVA EXCEL" 140 and "NOVA EXCEL" F5 manufactured by Rin Kagaku Kogyo KK.

As other non-halogen flame retardants, silicone flame retardants, low melting point glass, expandable graphite and the like can also be used.

In the present invention, the addition amount of the non-halogen flame retardant is 0.1 to 100 parts by weight of the polyamide resin (A).
1 to 50 parts by weight, preferably 0.5 to 40 parts by weight, more preferably 1 to 30 parts by weight, still more preferably 1 to 25 parts by weight
Parts by weight. If the amount is less than 0.1 part by weight, the flame retardancy tends to be poor. If the amount exceeds 50 parts by weight, the mechanical properties are inferior and the flame retardancy is rather deteriorated.

Specific examples of the fibrous reinforcing material as the component (C) of the present invention include glass fibers, carbon fibers, aramid fibers, potassium titanate fibers, metal fibers, and ceramic fibers. These fibrous reinforcing materials may be used alone or in combination of two or more. Among the above fibrous reinforcing materials, glass fibers are particularly preferably used. 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 short fiber type chopped strand, milled fiber or the like. The fiber diameter is not limited, but is 6 to 20.
Those having a range of μm are preferably used.

These glass fibers may be coated or bundled with an ethylene / vinyl acetate copolymer or the like or a thermosetting resin, and may be treated with a silane-based, titanate-based coupling agent, or another surface treatment agent. Are particularly preferably used. The amount of the fibrous reinforcement added is preferably 0 to 150 parts by weight, particularly preferably 0 to 100 parts by weight, based on 100 parts by weight of the polyamide resin (A). If the amount exceeds 150 parts by weight, the fluidity of the resin composition is extremely reduced, and the moldability is impaired, which is not preferable.

The polyethylene terephthalate resin as the component (D) of the present invention refers to a high molecular weight thermoplastic polyester obtained by polymerizing terephthalic acid or a derivative thereof as an acid component and ethylene glycol or a derivative thereof as a glycol component. In addition, as an acid component within a range that does not impair the object of the present invention, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, oxalic acid, adipic acid,
1,4-cyclohexanedicarboxylic acid or a derivative thereof as a glycol component, such as propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, bisphenol A, or a derivative thereof Can be partially used. Among them, copolymerized polyethylene terephthalate using terephthalic acid as a dicarboxylic acid component and ethylene glycol and cyclohexanedimethanol as glycol components is preferably used in the copolymerized polyester. When copolymerized, the copolymerization amount is 30% of the acid component.
It is preferable that the content is not more than 30 mol% of the glycol component.

The polyethylene terephthalate used in the present invention has an intrinsic viscosity of 0.25 to 0.25 measured at 25 ° C. using a 1: 1 mixed solvent of phenol / tetrachloroethane.
Those having a range of 3.00 dl / g, particularly 0.40 to 2.25 dl / g, are suitable.

The amount of the polyethylene terephthalate resin in the present invention is 0.1 to 50 parts by weight, preferably 0.1 to 30 parts by weight, per 100 parts by weight of the polyamide resin.
Parts by weight, more preferably 1 to 30 parts by weight, further preferably 2 to 27 parts by weight, particularly preferably 5 to 25 parts by weight. If the amount is less than 0.1 part by weight, the flame retardancy tends to be poor. If the amount exceeds 50 parts by weight, sufficient flame retardancy cannot be obtained and the heat resistance becomes poor.

The addition of the fluororesin as the component (E) of the present invention causes dropping (drip) of droplets during combustion.
Suppress. Examples of such a fluorine resin include polytetrafluoroethylene, polyhexafluoropropylene, (tetrafluoroethylene / hexafluoropropylene) copolymer, (tetrafluoroethylene / perfluoroalkylvinyl ether) copolymer, and (tetrafluoroethylene / Ethylene) copolymer, (hexafluoropropylene / propylene) copolymer, polyvinylidene fluoride, (vinylidene fluoride / ethylene) copolymer and the like. Among them, polytetrafluoroethylene, (tetrafluoroethylene / (Perfluoroalkyl vinyl ether) copolymer, (tetrafluoroethylene / hexafluoropropylene) copolymer, (tetrafluoroethylene / ethylene) copolymer, and polyvinylidene fluoride are preferred. Polytetrafluoroethylene, (tetrafluoroethylene / ethylene) copolymer are preferable.

The amount of the fluororesin to be added is usually 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts by weight of the polyamide resin (A) from the viewpoint of mechanical properties and moldability.
Parts by weight, more preferably 0.2 to 3 parts by weight.

The flame-retardant polyamide resin composition of the present invention may contain, as additives, hydrotalcites, alkali metal carbonates, alkaline earth metal carbonates and the like as additives for improving its properties. The addition amount is preferably in the range of 0.01 to 10 parts by weight based on 100 parts by weight of the flame-retardant polyamide resin composition. These additives mainly have an effect of reducing the odor of the composition and an effect of preventing corrosion of the molding machine and the mold.

In order to maintain the heat resistance of the flame-retardant polyamide resin composition of the present invention for a long period of time, hindered phenol-based, hydroquinone-based, phosphite-based and substituted products thereof are used as heat-resistant stabilizers. copper,
Potassium iodide and the like can be added. In particular, the combined use of copper iodide and potassium iodide is effective for the highly heat-resistant flame-retardant polyamide resin composition of the present invention. Copper iodide is added in an amount of 0.001 to 2 parts by weight and potassium iodide in an amount of 0.01 to 100 parts by weight based on 100 parts by weight of the flame-retardant polyamide resin composition.
It is effective to add within the range of ~ 6 parts by weight.

As additives other than those described above, the following additives, such as weathering stabilizers (resorcinol-based, salicylate-based, benzotriazole-based, benzophenone-based, and hindered amine-based), as long as the properties of the composition are not impaired. Molds and lubricants (montanic acid and its salts,
Its esters, its half esters, stearyl alcohol, stearamide, 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, gypsum, red iron, graphite, etc.) may be added.

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 effectively used for office electrical product parts, computer-related parts, facsimile / copier-related parts, machine-related parts, and various other uses.

[0039]

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) Melting Point The melting point was measured at a heating rate of 20 ° C./min using an RDC220 type differential working calorimeter manufactured by Seiko Instruments Inc.

(2) Viscoelastic Behavior A polyamide resin sample was melt-pressed to a thickness of about 0.2
mm, a 2 × 50 mm strip-shaped test piece was cut out from the sheet, and the measurement was performed using a Toyo Baldwin-made Reovibron DDV-II-EA at a frequency of 110 Hz and a heating rate of 2 ° C./min. . The peak temperature of the loss elastic modulus corresponding to α-dispersion was defined as the glass transition point. In addition, the peak temperature of the highest temperature of the loss elastic modulus observed by splitting specifically at the time of water absorption is shown in the table as the high temperature side peak at the time of water absorption.

(3) Physical Properties Tensile strength: measured according to ASTM D638. B. Flexural strength, flexural modulus: measured according to ASTM D760. C. Izod impact strength: measured according to ASTM D256. D. Deflection temperature under load: Measured according to ASTM D648.

E. Molding shrinkage: ASTM No. 4 dumbbell test piece was molded, and from the length of the mold in the longitudinal direction,
The numerical value obtained by dividing the numerical value obtained by subtracting the length in the long direction of the molded piece by the length in the long direction of the mold was expressed as a percentage. F. Dimensional change rate during water absorption: AST after measuring molding shrinkage
Using M4 dumbbell test piece, temperature 35 ° C, humidity 95%
After 135 hours of treatment and absorption in RH environment,
The value obtained by dividing the difference between the initial dimension and the dimension after the water absorption treatment by the initial dimension was expressed as a percentage.

(4) Moldability When the polyamide resin sample was subjected to injection molding under the following conditions, the degree of deformation (hollow) of the molding surface due to the mold protruding pin was visually evaluated. ○: no deformation, Δ: slight deformation, ×: large deformation Injection molding conditions Cylinder temperature: melting point + 15 ° C., mold temperature: 80 ° C., injection time: 3 seconds, cooling time: 7 seconds, molding pressure: minimum molding pressure + 10% (MPa · G), observation molded product: 1/2 ”Izod impact test piece

(5) Flammability Measured using a test piece having a thickness of 1/16 inch according to the method of UL94. Table 1 shows the compositions and melting points of the polyamide resins used in the examples.

REFERENCE EXAMPLE 1 Hexamethylene diammonium terephthalate (6T salt), hexamethylene terephthalamide (6T salt) prepared to have 65 mol% of hexamethylene terephthalamide unit, 15 mol% of hexamethylene isophthalamide unit and 20 mol% of dodecane amide unit An aqueous solution of diammonium isophthalate (6I salt) and 12-aminododecanoic acid (solid raw material concentration: 60% by weight) was charged into a pressure polymerization kettle,
The temperature was raised with stirring. The steam pressure was maintained at 35 kg / cm ² , and the reaction was carried out until the temperature in the polymerization vessel reached the melting point shown in Table 1. Then, while supplying the heating water to the polymerization vessel, the pressure in the polymerization vessel and the temperature in the polymerization vessel were maintained. The produced oligomer was discharged from the discharge port at the bottom of the polymerization vessel, and was cooled in a cooling bath. The relative viscosity of the obtained oligomer was 1.3.

The obtained oligomer was dried and pulverized and twin-screw extruder (TEX30XSSST: L manufactured by Nippon Steel Works, Ltd.)
/D=45.5), the resin temperature was raised to 330 ° C. and the degree of polymerization was increased by vacuum evacuation, extruded into strands, cooled in a cooling bath, and then pelletized with a cutter. The polyamide resin obtained here had a relative viscosity of 2.5. Table 1 shows the measurement results of the glass transition point at the time of water absorption, the peak on the high temperature side at the time of water absorption, and the bending elastic modulus at the time of drying (absolute drying) and at the time of water absorption.

Reference Examples 2 to 6, 8 Raw materials were prepared so as to have the compositions shown in Table 1, and polymerization was carried out in the same manner as in Reference Example 1. The relative viscosity of the obtained oligomer is 1.3 to
It was in the range of 1.4. The obtained oligomer was dried and pulverized, and pelletized with a twin screw extruder in the same manner as in Reference Example 1. The polyamide resin obtained here has a relative viscosity of 2.4 to
It was in the range of 2.6. Table 1 shows the measurement results of the glass transition point at the time of water absorption, the peak on the high temperature side at the time of water absorption, and the bending elastic modulus at the time of drying (absolute drying) and at the time of water absorption.

Reference Example 7 40 mol% of hexamethylene terephthalamide unit, 5 of hexamethylene dodecamide unit
Hexamethylene diammonium terephthalate (6 mol%, 5 mol% of caproamide unit)
T salt), hexamethylenediammonium dodecanoate (612 salt), and an aqueous solution of ε-caprolactam (6) (solid raw material concentration: 60% by weight) were charged into a pressure polymerization vessel, and the temperature was increased with stirring, and the steam pressure was 18 kg. After reacting at 1.5 cm / cm ² for 1.5 hours, the pressure was gradually released over about 2 hours, and the reaction was further performed under normal pressure nitrogen stream for 30 minutes. At this time, the temperature in the final polymerization reactor was 280 ° C. After completion of the reaction, the produced polymer was discharged in a strand form from the discharge port at the bottom of the polymerization vessel, cooled in a cooling bath, and pelletized. The polyamide resin obtained here had a relative viscosity of 2.4. Table 1 shows the measurement results of the glass transition point at the time of water absorption, the peak on the high temperature side at the time of water absorption, and the bending elastic modulus at the time of drying (absolute drying) and at the time of water absorption.

[0050]

[Table 1]

Examples 1 to 5 and Comparative Examples 1 to 3 Red phosphorus (“NOVA EXCEL 14” manufactured by Rin Kagaku Kogyo Co., Ltd.) was used in an amount shown in Table 2 with respect to 100 parts by weight of the polyamide resin shown in the reference example.
0 ”), polyethylene terephthalate (hereinafter abbreviated as PET) having an intrinsic viscosity of 0.65 (a mixed solvent of phenol / tetrachloroethane at a ratio of 1: 1 at 25 ° C.) and other additives are mixed, and a nitrogen flow is performed. Screw diameter 3
0 mm, L / D45.5, co-rotating twin screw extruder (manufactured by Nippon Steel Corporation, TEX-30), resin temperature 290-3
It was melt extruded at 30 ° C. After vacuum drying the obtained pellets, test pieces for evaluating physical properties and flame retardancy were prepared by injection molding (mold temperature: 80 ° C.) and measured.

Table 2 shows the measurement results of the characteristics of each sample. In the table, GF indicates glass fiber ("TN-202" manufactured by Nippon Electric Glass Co., Ltd.), and fluorine resin indicates polytetrafluoroethylene ("Teflon 6J" manufactured by DuPont-Mitsui Fluorochemicals). When glass fiber is blended, the glass fiber weight part in the resin composition is 3 parts by weight.
It was blended to be 0%. From Examples 1 to 5 and Comparative Examples 1 and 2, the compositions of the present invention are excellent in balance of flame retardancy, material strength, and heat resistance, and have good dimensional stability with small molding shrinkage and small change in water absorption. Thus, the moldability is high without practical problems and of high practical value.

[0053]

[Table 2]

[0054]

The flame-retardant polyamide resin composition obtained by preparing a polyamide having a melting point of 280 ° C. or more and less than 325 ° C. in a specific composition range using a specific polyamide raw material and making it flame-retardant is obtained. Excellent heat resistance, moldability, and dimensional stability. Particularly low in rigidity when absorbing water and small in dimensional change rate. High practical value as a molding material for industrial materials, industrial materials, electric / electronic materials, etc. .

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Claims (13)

[Claims] (1) The polyamide resin as the component (A) comprises:
75 to 45 mol% of hexamethylene terephthalamide units, (b) 10 to 25 mol% of hexamethylene isophthalamide and / or hexamethylene hexahydroterephthalamide units, and (c) the number of carbon atoms per amide group (amide group (Concentration) is 8 to 30 mol% of an aliphatic polyamide unit having a molecular weight of 8 or more, and further has 100 parts by weight of a polyamide resin whose properties are within the following ranges:
(B) A flame-retardant polyamide resin composition comprising 0.1 to 50 parts by weight of a non-halogen flame retardant. (A) Melting point: 280 ° C. or more and less than 325 ° C. (b) Glass transition point at the time of saturated water absorption determined by viscoelasticity measurement is 40 ° C. or more, and at least one peak among a plurality of peak values of the loss elastic coefficient observed. At 80 ° C
that's all 2. The flame-retardant polyamide resin composition according to claim 1, wherein the aliphatic polyamide unit of the component (c) is undecaneamide or dodecaneamide. 3. The flame-retardant polyamide resin composition according to claim 2, wherein the polyamide unit of component (c) is a dodecaneamide unit. 4. The polyamide resin (A) having a melting point of 3
The flame-retardant polyamide resin composition according to any one of claims 1 to 3, which is in the range of 00 to 325 ° C. 5. The flame-retardant polyamide resin composition according to claim 1, wherein the non-halogen flame retardant (B) is a phosphorus-containing flame retardant. 6. The flame-retardant polyamide resin composition according to claim 5, wherein the non-halogen flame retardant of the component (B) is red phosphorus. 7. The flame-retardant polyamide resin composition according to claim 6, wherein the component (B) non-halogen flame retardant is red phosphorus coated with a thermosetting resin. 8. The flame-retardant polyamide resin composition according to claim 1, further comprising 0 to 150 parts by weight of an inorganic filler (C) based on 100 parts by weight of the polyamide resin. 9. The flame-retardant polyamide resin composition according to claim 8, wherein the inorganic filler (C) is a fibrous reinforcing material. 10. The flame-retardant polyamide resin composition according to claim 9, wherein the fibrous reinforcing material is glass fiber. 11. The flame-retardant polyamide resin composition according to claim 1, which further comprises (D) 0.1 to 50 parts by weight of a polyethylene terephthalate resin based on 100 parts by weight of the polyamide resin. 12. The flame-retardant polyamide resin composition according to claim 1, further comprising (E) 0.01 to 10 parts by weight of a fluorine resin based on 100 parts by weight of the polyamide resin. 13. A molded article obtained by injection molding the flame-retardant polyamide resin composition according to claim 1.