JP2000017171A - Flame-retardant polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame-retardant polyamide resin composition having excellent mechanical characteristics, heat resistance, moldability and dimensional stability, slight reduction in rigidity in a water absorpted state and in rate of change of dimension. SOLUTION: This flame-retardant polyamide resin composition comprises (A) a polyamide resin which is composed of (a) 75-45 mol.% hexamethylene terephthalamide unit and (b) 25-55 mol.% of an aliphatic polyamide unit having >=8 carbon atoms (amide group concentration) per amide group and has characteristics of (i) >=280 deg.C and <325 deg.C melting point and (ii) >=40 deg.C glass transition point in saturated water absorption obtained from viscoelastic measurement and >=80 deg.C at least one peak position among peaks of plural observed elasticity losses, (B) a polymer flame-retardant having 55-70% halogen content and >=5,000 weight-average molecular weight and (c) a flame-retardant auxiliary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame retardant having excellent mechanical properties, heat stability, moisture resistance, and moldability, and particularly excellent in rigidity and dimensional stability when placed in a high humidity environment. The present invention relates to a polyamide resin composition. More specifically, it is difficult to maintain high toughness, which is a characteristic of polyamide resin, and to have high heat resistance, high moisture resistance, and high dimensional stability with extremely small decrease in rigidity even after long-term exposure to high humidity environment. The present invention relates to a flame-retardant polyamide resin composition, which can be suitably used as a molding material for a surface mount component requiring automotive heat resistance, electric / electronic use, and particularly 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. Among them, electric and electronic parts have a strong demand for flame retardancy, and it is a necessary condition that the electric / electronic parts are equivalent to V-0 in the UL standard. As a flame-retardant polyamide resin, for example, it is known to add a halogen-containing compound to a polyamide resin (for example, see JP-A-47-7134).
JP-A-48-29846, JP-A-51-29846
No. 47044, JP-A-61-188463,
JP-B-56-2100, JP-A-1-182366
Issue publication).

In recent years, semi-aromatic polyamide resins containing a terephthalic acid component have been developed in order to obtain low water absorption and high heat resistance. As representative examples, hexamethylene terephthalamide unit (6T) and hexamethylene adipamide unit (6
6) or a flame-retardant polyamide resin composition with a halogen-containing compound of a 66 / 6T or 6 / 6T copolymer which is a copolymer with a caproamide unit (6) (for example, EP04
10301B1) or 6T / which is a copolymer of a 6T component unit and a hexamethylene isophthalamide unit (6I).
Flame-retardant polyamide resin compositions of 6I copolymers with halogen-containing compounds (for example, JP-A-63-260951).

[0004]

However, flame-retardant polyamide resin compositions such as nylon 6, nylon 66, etc., which are widely used as polyamide resins of the prior art, have a large decrease in rigidity when absorbing water and have a low solder heat resistance. The required surface mount component material has insufficient heat resistance and is difficult to use. A flame-retardant polyamide resin composition using nylon 46 having a high melting point has high heat resistance, but has high water absorption, has a significant decrease in rigidity due to water absorption, and has disadvantages such as lack of dimensional stability.

Also, a flame-retardant polyamide resin composition using a semi-aromatic polyamide resin, for example, 6 / 6T, 66/6
Each of the flame-retardant polyamide resin compositions based on the T-copolymerized polyamide resin has a problem in thermal stability such as foaming during melt retention, and has a large decrease in rigidity and large dimensional change due to water absorption. On the other hand, a flame-retardant polyamide resin composition based on a 6T / 6I copolymer polyamide resin has a high water absorption due to poor crystallinity of the base polyamide resin,
There is a strong demand for the emergence of a flame-retardant polyamide resin composition having both heat resistance and dimensional stability, such as having problems such as poor thermal stability.

Accordingly, the present invention provides a flame-retardant polyamide resin composition having excellent mechanical properties, moldability and dimensional stability, particularly excellent heat resistance, a small decrease in rigidity upon water absorption, and a small dimensional change. The purpose is to:

[0007]

In order to achieve the above object, the present invention comprises the following flame-retardant polyamide resin composition. 1. (A) 75-45 mol% of (a) hexamethylene terephthalamide units and (b) 25-55 mol% of aliphatic polyamide units having 8 or more carbon atoms (amide group concentration) per amide group, Further, it is characterized by comprising a polyamide resin having the following properties, (B) a polymer flame retardant having a halogen content of 55 to 70%, a weight average molecular weight of 5,000 or more, and (C) a flame retardant auxiliary. Flame retardant polyamide resin composition. (B) Melting point: 280 ° C. or more and less than 325 ° C. (b) At least one of the plurality of peaks of the loss elastic modulus having a glass transition point of 40 ° C. or more at the time of saturated water absorption determined from viscoelasticity measurement and a plurality of observations. Is 80 ° C or higher (A) hexamethylene terephthalamide unit 75 to
45 mol% and (b ′) the number of carbon atoms per one amide group (amide group concentration) is 8 or more, and the following (c)
20 to 50 mol% of an aliphatic polyamide unit not defined as a component, and (c) 5 to 15 mol% of at least one structural unit selected from undecane amide units, dodecane amide units, and caproamide units. Is a polyamide resin having the following range, (B)
Halogen content 55-70%, weight average molecular weight 5000
A flame-retardant polyamide resin composition comprising the above polymer flame retardant and (C) a flame retardant auxiliary. (B) Melting point: 280 ° C. or more and less than 325 ° C. (b) At least one of the plurality of peaks of the loss elastic modulus having a glass transition point of 40 ° C. or more at the time of saturated water absorption determined from viscoelasticity measurement and a plurality of observations. Is 80 ° C or higher. (A) (a) 75 to 45 mol% of hexamethylene terephthalamide units, (b) 20 to 50 mol% of aliphatic polyamide units having 8 or more carbon atoms (amide group concentration) per amide group, and (d) A) a polyamide resin comprising 5 to 25 mol% of hexamethylene isophthalamide units and further having the following characteristics: (B) a polymeric flame retardant having a halogen content of 55 to 70% and a weight average molecular weight of 5000 or more; (C) A flame-retardant polyamide resin composition comprising a flame-retardant auxiliary. (B) Melting point: 280 ° C. or more and less than 325 ° C. (b) At least one of the plurality of peaks of the loss elastic modulus having a glass transition point of 40 ° C. or more at the time of saturated water absorption determined from viscoelasticity measurement and a plurality of observations. Is 80 ° C or higher

[0008] 4. The amounts of the components (A), (B) and (C) are 40 to 80% by weight for (A) and 1% for (B), respectively.
4. The flame retardant according to the above 1, 2, or 3, wherein 0 to 35% by weight and (C) are in the range of 1 to 15% by weight, and (A) + (B) + (C) = 100% by weight. Polyamide resin composition. 5. (1) or (2) wherein the aliphatic polyamide unit of the component (b) or the component (b ′) is hexamethylene sebacamide.
Item 10. The flame-retardant polyamide resin composition according to any one of the above items. 6. 4. The flame-retardant polyamide resin composition according to any one of the above items 1, 2 or 3, wherein the aliphatic polyamide unit of the component (b) or the component (c) is undecaneamide or dodecaneamide. 7. 3. The flame-retardant polyamide resin composition according to the above item 2, wherein the aliphatic polyamide unit of the component (c) is caproamide. 8. 3. The flame-retardant polyamide resin composition according to the above item 2, wherein the aliphatic polyamide unit of the component (c) is dodecaneamide. 9. 3. The flame-retardant polyamide resin composition according to claim 2, wherein the aliphatic polyamide unit of the component (b ′) is hexamethylene sebacamide and the aliphatic polyamide unit of the component (c) is caproamide. 10. 3. The flame-retardant polyamide resin composition according to the above item 2, wherein the aliphatic polyamide unit of the component (b ′) is hexamethylene sebacamide and the aliphatic polyamide unit of the component (c) is dodecaneamide.

[0011] 11. 11. The flame-retardant polyamide resin composition according to any one of the above items 1 to 10, wherein the polyamide resin as the component (A) has a melting point of 300 ° C. or more and less than 325 ° C. 12. (B) The flame retardant as a component has a 1% heating weight loss temperature of 3
12. The flame-retardant polyamide resin composition according to any one of the above items 1 to 11, which is at least one selected from brominated polystyrene and brominated polyphenylene ether at a temperature of 00 ° C or higher. 13. 13. The flame-retardant polyamide resin composition according to any one of the above items 1 to 12, wherein the flame-retardant auxiliary as the component (C) is at least one selected from a metal oxide and a metal borate. 14． Item 14. The flame-retardant polyamide resin composition according to any one of Items 1 to 13, further comprising an inorganic filler as a component (D). 15. 15. The flame-retardant polyamide resin composition according to any one of the above items 1 to 14, wherein the amount of the inorganic filler as the component (D) is 40% by weight or less based on the whole resin composition. 16. 16. The flame-retardant polyamide resin composition according to the above item 14 or 15, wherein the inorganic filler as the component (D) is a fibrous reinforcing material. 17． 17. The flame-retardant polyamide resin composition according to the above 16, wherein the fibrous reinforcing material is glass fiber. 18. A molded article obtained by injection molding the flame-retardant polyamide resin composition according to any one of the above 1 to 17.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The (a) hexamethylene terephthalamide unit constituting the polyamide resin as the component (A) of the present invention is synthesized from hexamethylene diamine and a derivative such as terephthalic acid or an ester or an acid halide. Unit. 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 the component (b) include hexamethylene diammonium sebacate and hexamethylene diammonium decano. Ethate, hexamethylenediammonium dodecanoate, 12-aminododecanoic acid, ω-laurolactam, 11-aminoundecanoic acid and the like can be mentioned. In the present invention, the component (c) is a unit derived from a raw material such as ε-caprolactam, ω-laurolactam, ε-aminocaproic acid, 12-aminododecanoic acid, and 11-aminoundecanoic acid. In the present invention according to claim 3, the (d) hexamethylene isophthalamide unit is a unit synthesized from hexamethylene diamine and a derivative such as isophthalic acid or an ester or an acid halide.

These polyamide constituents are described in claim 1
In the case of the two-component system, the components (a) and (b)
5 to 45 mol%, 25 to 55 mol%,
In the case of the three-component system according to claim 2, components (a) to (c) are contained in proportions of 75 to 45 mol%, 50 to 20 mol%, and 5 to 15 mol%, respectively, and component (d). 4. In the case of the three-component system according to claim 3, which contains a hexamethylene isophthalamide unit of the formula (1), wherein each of the components (a), (b) and (d) is 75
In the present invention, it is necessary and important that the copolymer be contained at a ratio of about 45 mol%, 20 to 50 mol%, and 5 to 25 mol%. 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. This is because there is no decrease in rigidity at the same time, and preferable performances such as excellent balance of heat resistance, toughness, moldability, dimensional stability, especially dimensional stability at the time of water absorption can be exhibited. Particularly, at the time of water absorption, the glass transition point of 40 ° C. or more is maintained, and the loss elastic modulus peak is 80
It is important that there are segments above ° C.

When the copolymerization amount of the component (a) is more than the above range, the melting point of the polyamide resin to be formed becomes high, and the heat stability is impaired, for example, deterioration during melting becomes apparent, and the moldability is deteriorated. On the other hand, when the amount is less than the above range, rigidity and dimensional stability at the time of water absorption are reduced, and a desired melting point is not obtained, and heat resistance is reduced, so that it cannot be used for the intended application. When the copolymerization amount of the component (b) is more than the above range, the melting point is lowered, and the required heat resistance cannot be maintained. Conversely, if it is less than the above range, the water absorption increases, and the rigidity at the time of water absorption decreases. In the case of a three-component system, if the copolymerization amount of the component (c) is larger than the above range, the melting point also decreases in this case, and the required heat resistance cannot be maintained. Conversely, if the amount is less than the above range, the fluidity of the polyamide resin produced is reduced, and the significance of the introduction of the component (c) is reduced. If the copolymerization amount of the component (d) is larger than the above range, also in this case, the melting point is lowered, so that the required heat resistance cannot be maintained and the crystallinity is reduced, and the required physical properties are impaired. Conversely, if the amount is less than the above range, the significance of the introduction of the component (d) is diminished.

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 sebacate (61
0) and a mixed aqueous solution of ε-caprolactam
The reaction is carried out under a steam pressure of 40 kg / cm ² under a steam pressure, and then a conventional melt polymerization method in which melt polymerization is carried out while releasing water in the system, or a raw material aqueous solution is heated to 250 to 330 ° C. to form a prepolymer once. , Or a method of extruding a prepolymer with a melt extruder to increase the degree of polymerization.

As the flame retardant as the component (B) of the present invention, a halogen-based flame retardant having a halogen content of 55 to 70% and a weight average molecular weight of 5,000 or more is used. In particular, it is most preferable that the 1% heating loss temperature is 300 ° C. or higher from the viewpoint of heat stability. Halogen-based flame retardants satisfying these conditions include brominated polystyrene (including poly (dibrominated styrene)) having a halogen content of 55 to 70% by weight and a weight average molecular weight of 5,000 or more, and brominated polyphenylene. Ether is mentioned, and is preferably used. The measurement of the 1% weight loss by heating is carried out by using a 8095B1 type heating gravimetric analyzer manufactured by Rigaku Denki Co., Ltd., and measuring the weight loss at a heating rate of 20 ° C./min to determine the temperature at which the 1% weight loss occurs. Perform in.

Each of the above flame retardants can be used alone or in the form of a mixture. The amount of the flame retardant is preferably 10 to 35% by weight of the composition. If the amount is less than 10% by weight, the flame-retardant effect becomes insufficient, which is not preferable.
Exceeding the range is not preferred because mechanical properties such as impact properties of the resin composition are reduced.

The flame retardant aid used as component (C) in the present invention is selected from metal oxides and metal borate salts. Specific examples of the metal oxide include antimony trioxide, sodium antimonate, zinc oxide, ferrous oxide, ferric oxide, stannous oxide, stannic oxide, and magnesium oxide. Specific examples of the metal borate include sodium borate, zinc borate, magnesium borate, calcium borate, manganese borate, and the like. These can be used alone or in the form of a mixture of two or more. The addition amount of the flame retardant aid is preferably 1 to 15% by weight, particularly preferably 3 to 10% by weight in the composition. If the addition amount of the flame retardant auxiliary is less than 1% by weight, the effect as an auxiliary is small, and the flame retardancy is insufficient.
Exceeding the percentage by weight is not preferred because mechanical properties such as impact resistance are reduced.

In the present invention, an inorganic filler can be added as the component (D), and among them, a fibrous reinforcing material is preferably used. Specific examples of the fibrous reinforcement include glass fiber, carbon fiber, aramid fiber, potassium titanate fiber,
Examples include 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 and the like. The fiber diameter is not limited, but a fiber diameter of 6 to 20 μm is preferably used. These glass fibers may be coated or bundled with an ethylene / vinyl acetate copolymer or the like or a thermosetting resin, and are treated with a silane-based, titanate-based coupling agent, or another surface treatment agent. One is appropriately selected and used. The amount of the inorganic filler to be added is 40% by weight or less based on the whole resin composition. If the amount exceeds 40% by weight, the fluidity of the resin composition is extremely lowered and the moldability is impaired, which is not preferable.

The flame-retardant polyamide resin composition of the present invention may contain additives such as hydrotalcites, alkali metal carbonates and alkaline earth metal carbonates as additives for improving the properties thereof. 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.

Further, 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, for example, flame retardants other than those described above (for example, triazine-based flame retardants such as melamine cyanurate, melamine, cyanuric acid, melon) as long as they do not impair the properties of the composition. Melam and the like, polyphosphoric acid, phosphate esters, etc.), flame retardant aids (fluororesins represented by polytetrafluoroethylene, silicone resins, phenol novolak resins, polyalkyl acrylate rubbers, polyethers) Resins such as terimide, polyphenylene sulfide, polyimide, polyarylate, polyphenylene ether), weathering stabilizers (resorcinol, salicylate, benzotriazole, benzophenone, hindered amine, etc.), release agents and lubricants (Montan Acids and their salts, their esters, Half-esters, stearyl alcohol, stearamide, polyethylene wax, etc.), pigments (cadmium sulfide, phthalocyanine, carbon black, etc.) and dyes (nigrosine, etc.), fillers (glass beads, talc, kaolin, wollastenite, mica, silica, diatomaceous) Soil, clay, stone, bengara, graphite, etc.) may be added.

The flame-retardant polyamide resin composition of the present invention is used in 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.

[0024]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

The properties in Examples and Comparative Examples were measured by the following methods. (1) Melting point: RDC220 manufactured by Seiko Electronic Industry Co., Ltd.
The measurement was performed at a heating rate of 20 ° C./min using a type differential working calorimeter. (2) Viscoelastic behavior: A polyamide resin sample was melt-pressed to prepare a sheet having a thickness of about 0.2 mm, and a 2 × 50 mm strip-shaped test piece was cut out therefrom, and Toyo Baldwin's Leo Vibron DDV-II was used. The measurement was performed using -EA under the conditions of 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. The highest peak temperature of the loss elastic modulus observed by splitting specifically at the time of water absorption was taken 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. FIG. Molding shrinkage: A test piece of ASTM No. 4 dumbbell was molded, and the value obtained by subtracting the length in the longitudinal direction of the mold from the length in the longitudinal direction of the mold was divided by the length in the longitudinal direction of the mold. Values are expressed as percentages. F. Dimensional change upon water absorption: ASTM after molding shrinkage measurement
Using No. 4 dumbbell specimen, temperature 35 ° C, humidity 95% R
The value obtained by dividing the difference between the initial dimension after the water absorption treatment and the dimension after the water absorption treatment in the environment of H for 135 hours by the initial dimension was expressed as a percentage.

(4) Flammability: Measured using a test piece having a thickness of 1/16 inch according to the method of UL94.

In Examples and Comparative Examples, the flame retardants shown in Table 1 were used. Moreover, the polyamide resin obtained by the production method of the following Reference Examples 1 to 9 and having physical properties shown in Table 2 was used.
The polyamide resins of Reference Examples 1 to 3 are the present invention of Claim 1, the polyamide resins of Reference Examples 5 and 6 are the present invention of Claim 2, and the polyamide resin of Reference Example 8 is the present invention of Claim 3. It is used in the invention.

[0029]

[Table 1]

REFERENCE EXAMPLE 1 An aqueous solution of hexamethylene diammonium terephthalate (6T salt) and 12-aminododecanoic acid (solid raw material concentration) prepared to have 50 mol% of hexamethylene terephthalamide units and 50 mol% of dodecane amide units 60% by weight) into a pressure polymerization kettle,
After raising the temperature under stirring and reacting at a steam pressure of 35 kg / cm ² for 1.5 hours, the pressure was gradually released over about 2 hours, and the reaction was further performed under a normal pressure nitrogen stream for 30 minutes. At this time, the temperature in the final polymerization reactor was 310 ° 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 2 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 to 9 Compositions shown in Table 2
The raw material is prepared so that
% By weight of sodium hypophosphite,
Similarly, a raw material aqueous solution (solid raw material concentration: 60% by weight) is
The mixture was charged into a kegama and heated with stirring. 35kg / cm steam pressure^Two
And react until the temperature in the polymerization vessel reaches the melting point shown in Table 2.
After heating, supply heated water to the
While maintaining the temperature inside the polymerization kettle,
The oligomer was discharged and cooled in a cooling bath. Got here
The relative viscosity of the oligomer obtained is in the range of 1.3 to 1.4.
Was. The obtained oligomer is dried and pulverized to obtain a twin screw extruder.
(TEX30XSSST manufactured by Japan Steel Works Ltd .: L / D =
At 45.5), evacuate the resin to 330 ° C and vent.
High polymerization degree, extruded into strands, cooled in cooling bath
After that, the mixture was pelletized with a cutter. The poly obtained here
The amide resin has a relative viscosity in the range of 2.4 to 2.6.
Was. Glass transition point at water absorption, hot side peak at water absorption and dry
Table 2 shows the measurement results of flexural modulus during drying (absolute drying) and water absorption.
It was shown to.

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 a 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.

[0033]

[Table 2]

Example 1 The polyamide resin of Reference Example 1 was blended in the blending amounts shown in Table 3 and mixed with a blender.
The mixture was extruded into a strand by a 0 mmφ single screw extruder (Tanabe VS40-32), cooled in a cooling tank, and pelletized by a cutter. After vacuum drying the flame-retardant polyamide resin composition, injection molding was performed to form various test pieces, and the characteristics were measured. As shown in Table 3, both the molding shrinkage rate and the water absorption dimensional change rate were small. And a composition having good dimensional stability.

[Comparative Example 1] The polyamide resin of Reference Example 6 was blended in the blending amounts shown in Table 3 and mixed with a blender.
The mixture was extruded into a strand by a 0 mmφ single screw extruder (Tanabe VS40-32), cooled in a cooling tank, and pelletized by a cutter. The flame-retarded polyamide resin composition was vacuum-dried, injection-molded to form various test pieces, and the properties were measured. As shown in Table 3, the molding shrinkage and the water absorption dimensional change were as shown in Table 3. The composition was larger than the composition and had poor dimensional stability.

[Comparative Example 2] The polyamide resin of Reference Example 7 was blended in the blending amounts shown in Table 3 and mixed with a blender.
The mixture was extruded into a strand by a 0 mmφ single screw extruder (Tanabe VS40-32), cooled in a cooling tank, and pelletized by a cutter. The flame-retarded polyamide resin composition was vacuum-dried, injection-molded to form various test pieces, and the characteristics were measured. As shown in Table 3, although the dimensional change upon water absorption was small, the melting point of the polyamide resin was low. , The heat distortion temperature was low and the composition had poor heat resistance.

[Comparative Example 3] The polyamide resin of Reference Example 9 was blended in the blending amounts shown in Table 3 and mixed with a blender.
The mixture was extruded into a strand by a 0 mmφ single screw extruder (Tanabe VS40-32), cooled in a cooling tank, and pelletized by a cutter. After vacuum drying the flame-retardant polyamide resin composition, injection molding was performed to mold various test pieces, and the properties were measured. As shown in Table 3, the molding shrinkage was large and the dimensional stability was poor. Was. However, since the melting point of the polyamide resin was low, the heat distortion temperature was low and the composition had poor heat resistance.

Examples 2 to 6 The polyamide resins of Reference Examples 2 to 5 and 8 were blended in the amounts shown in Table 3 and mixed by a blender, followed by a 40 mmφ single screw extruder (Tanabe VS40-3).
It was extruded into a strand in 2), cooled in a cooling bath, and pelletized with a cutter. The flame-retarded polyamide resin composition was vacuum-dried, injection-molded to form various test pieces, and the characteristics were measured. As shown in Table 3, the molding shrinkage rate and the water absorption dimensional change rate were small, and the dimensional stability was small. It was a good composition.

[0039]

[Table 3]

[0040]

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. .

[Procedure amendment]

[Submission date] June 3, 1999 (1999.6.3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction contents]

[0039]

[Table 3]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 71/12 C08L 71/12

Claims (18)

[Claims] (1) (A) 75 to 45 mol% of (a) hexamethylene terephthalamide unit and (b) 25 to 55 of an aliphatic polyamide unit having 8 or more carbon atoms (amide group concentration) per amide group. Mol%, the properties of which are within the following ranges: a polyamide resin, (B) a polymeric flame retardant having a halogen content of 55 to 70%, a weight average molecular weight of 5,000 or more, and (C) a flame retardant auxiliary. A flame-retardant polyamide resin composition, characterized in that: (B) Melting point: 280 ° C. or more and less than 325 ° C. (b) The glass transition point at the time of saturated water absorption determined by viscoelasticity measurement is 40 ° C. or more, and at least one of a plurality of peaks of the loss elastic coefficient observed. Position is over 80 ℃ 2. (A) 75-45 mol% of (a) hexamethylene terephthalamide unit and (b ′) amide group 1
Number of carbon atoms per unit (amide group concentration is 8 or more,
And 20 to 50 mol% of an aliphatic polyamide unit which is not defined in the following component (c), and (c) 5 to 15 mol% of at least one structural unit selected from undecanamide units, dodecaneamide units and caproamide units. And a polyamide resin having the following properties: (B) a polymeric flame retardant having a halogen content of 55 to 70% and a weight average molecular weight of 5,000 or more; and (C) a flame retardant auxiliary. Flame-retardant polyamide resin composition. (B) Melting point: 280 ° C. or higher and lower than 325 ° C. (b) Position of at least one of a plurality of peaks of the loss elastic coefficient where the glass transition point at the time of saturated water absorption obtained from viscoelasticity measurement is 40 ° C. or higher and a plurality of peaks are observed. Is 80 ° C or higher 3. (A) (a) 75 to 45 mol% of hexamethylene terephthalamide units, and (b) 20 to 50 of aliphatic polyamide units having 8 or more carbon atoms (amide group concentration) per amide group. (D) a polyamide resin consisting of 5 to 25 mol% of hexamethylene isophthalamide units and having properties within the following ranges:
(B) Halogen content 55-70%, weight average molecular weight 5
A flame-retardant polyamide resin composition comprising at least 000 polymeric flame retardants and (C) a flame retardant auxiliary. (B) Melting point: 280 ° C. or more and less than 325 ° C. (b) At least one of the plurality of peaks of the loss elastic modulus having a glass transition point of 40 ° C. or more at the time of saturated water absorption determined from viscoelasticity measurement and a plurality of observations. Is 80 ° C or higher 4. The amounts of components (A), (B) and (C) added are (A) 40 to 80% by weight and (B) 10%, respectively.
4. The flame retardant according to claim 1, wherein the content of (A) + (B) + (C) is 100% by weight, wherein (A) + (B) + (C) is in the range of 1 to 15% by weight. Polyamide resin composition. 5. The flame-retardant polyamide resin composition according to claim 1, wherein the aliphatic polyamide unit of the component (b) or the component (b ′) is hexamethylene sebacamide. 6. The flame-retardant polyamide resin composition according to claim 1, wherein the aliphatic polyamide unit of the component (b) or the component (c) is undecaneamide or dodecaneamide. 7. The flame-retardant polyamide resin composition according to claim 2, wherein the aliphatic polyamide unit of the component (c) is caproamide. 8. The flame-retardant polyamide resin composition according to claim 2, wherein the aliphatic polyamide unit of the component (c) is dodecaneamide. 9. The flame-retardant polyamide resin composition according to claim 2, wherein the aliphatic polyamide unit of component (b ′) is hexamethylene sebacamide and the aliphatic polyamide unit of component (c) is caproamide. 10. The flame-retardant polyamide resin composition according to claim 2, wherein the aliphatic polyamide unit of the component (b ′) is hexamethylene sebacamide, and the aliphatic polyamide unit of the component (c) is dodecaneamide. . 11. The flame-retardant polyamide resin composition according to claim 1, wherein the polyamide resin (A) has a melting point of 300 ° C. or more and less than 325 ° C. 12. The flame retardant as the component (B) is at least one selected from brominated polystyrene and brominated polyphenylene ether having a 1% weight loss on heating of 300 ° C. or higher. 3. The flame-retardant polyamide resin composition according to item 1. 13. The flame-retardant polyamide resin according to claim 1, wherein the flame-retardant auxiliary as the component (C) is at least one selected from a metal oxide and a metal borate. Composition. 14. The flame-retardant polyamide resin composition according to claim 1, further comprising an inorganic filler as the component (D). 15. The flame-retardant polyamide resin composition according to claim 14, wherein the amount of the inorganic filler as the component (D) is 40% by weight or less based on the whole resin composition. 16. The flame-retardant polyamide resin composition according to claim 14, wherein the inorganic filler as the component (D) is a fibrous reinforcing material. 17. The flame-retardant polyamide resin composition according to claim 16, wherein the fibrous reinforcing material is glass fiber. 18. A molded article obtained by injection molding the flame-retardant polyamide resin composition according to claim 1. Description: