JPH11302534A - Flame-retardant bolyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame-retardant polyamide resin, excellent in mechanical properties, resistance to heat, formability and dimensional accuracy, and low in loss of rigidity and dimensional change when it absorbs moisture. SOLUTION: This composition is composed of (A) 100 pts.wt. of a polyamide resin, containing amide structural units derived from an aliphatic and alicyclic diamine having a carbon number of 6 to 12 and terephthalic acid, having a carbon number of 7 or more per one amide group (amide group concentration), and a melting point of 280 deg.C or more but less than 325 deg.C, and (B) 0.1 to 50 pts.wt. of non-halogen-based flame retardant.

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.

Accordingly, an object of the present invention is to provide a flame-retardant polyamide resin composition having excellent mechanical properties, moldability and dimensional stability, particularly excellent heat resistance and a small dimensional change upon water absorption. .

[0008]

That is, the present invention provides (1) "(A) an amide structural unit derived from an aliphatic or alicyclic diamine having 6 to 12 carbon atoms and terephthalic acid, The number of carbon atoms (amide group concentration) per group is 7 or more, and the melting point is 280 ° C. or more.
100 parts by weight of a polyamide resin having a temperature of less than 5 ° C., and
(B) A flame-retardant polyamide resin composition comprising 0.1 to 50 parts by weight of a non-halogen flame retardant. "
(2) "The flame-retardant polyamide resin composition according to the above (1), wherein the dicarboxylic acid component forming the amide structural unit of the polyamide resin of the component (A) is all terephthalic acid." 3) The polyamide resin of the component (A) is (a) a hexamethylene terephthalamide unit of 75 to 4
5 mol% and (b) an aliphatic polyamide unit 25 having 8 or more carbon atoms (amide group concentration) per amide group
(1) The flame-retardant polyamide resin composition according to the above (1), wherein the composition is within the following range. (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
(4) "The polyamide resin of the component (A) is (a)
Hexamethylene terephthalamide unit: 75 to 45 mol%, (b ') an aliphatic polyamide unit having a carbon number per amide group (amide group concentration) of 8 or more and not defined by the following component (c): 20 mol%, and (c) 5 to 15 mol% of at least one structural unit selected from undecane amide units, dodecane amide units and caproamide units, and the characteristics thereof are within the following ranges. The flame-retardant polyamide resin composition according to the above (1). (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
that's all",

(5) The flame-retardant polyamide resin composition according to (3) or (4), wherein the aliphatic polyamide unit of the component (b) or (b ') is hexamethylene sebacamide. "The flame-retardant polyamide resin composition according to the above (3) or (4), wherein the aliphatic polyamide unit of the component (b) or (c) is undecaneamide or dodecaneamide.", (7) "(c) The flame-retardant polyamide resin composition according to the above (4), wherein the polyamide unit of the component is a caproamide unit. ", (8)" The flame retardant of the above (4), wherein the polyamide unit of the component (c) is a dodecaneamide unit. (9) "(b ') wherein the aliphatic polyamide unit of the component (b') is hexamethylene sebacamide and the polyamide unit of the component (c) is a caproamide unit. (10) wherein the aliphatic polyamide unit of the component (b ') is hexamethylene sebacamide and the polyamide unit of the component (c) is a dodecaneamide unit. The flame-retardant polyamide resin composition according to the above. "

(11) The above (1) to (4), wherein the melting point of the polyamide resin (A) is in the range of 300 to 325 ° C.
(10) The flame-retardant polyamide resin composition according to any of the above. (12) The flame-retardant polyamide resin composition according to any one of the above (1) to (11), wherein the non-halogen flame retardant of the component (B) is a phosphorus-containing flame retardant. )
The above (1) wherein the non-halogen flame retardant of the component (B) is red phosphorus.
The flame-retardant polyamide resin composition according to 2). ”, (1
4) “The flame-retardant polyamide resin composition according to the above (13), wherein the non-halogen flame retardant of the component (B) is red phosphorus coated with a thermosetting resin.”, (15) “Polyamide resin 1”
The flame-retardant polyamide resin composition according to any one of the above (1) to (14), further comprising (C) 0 to 150 parts by weight of an inorganic filler based on 00 parts by weight. ”, (16)
"The flame-retardant polyamide resin composition according to the above (15), wherein the inorganic filler of the component (C) is a fibrous reinforcing material."
(17) The above (1) wherein the fibrous reinforcing material is glass fiber.
The flame-retardant polyamide resin composition according to 6). ”, (1
8) The flame-retardant polyamide resin composition according to any one of the above (1) to (17), further comprising (D) 0.1 to 50 parts by weight of a polyethylene terephthalate resin based on 100 parts by weight of the polyamide resin. (19) "(E) fluorine resin 0.0 per 100 parts by weight of polyamide resin.
(1) to (1) further containing 1 to 10 parts by weight.
8) The flame-retardant polyamide resin composition according to any one of the above items. And (20) a molded article obtained by injection molding the flame-retardant polyamide resin composition according to any one of the above 1 to 19.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The polyamide resin used as the component (A) in the present invention contains an amide structural unit derived from an aliphatic or alicyclic diamine having 6 to 12 carbon atoms and terephthalic acid. A polyamide resin having 7 or more carbon atoms per one group (amide group concentration). Among the combinations of lactams or amino acids having 7 or more carbon atoms and diamines and dicarboxylic acids, the content of the terephthalic acid derivative It is a polyamide resin containing a structural unit derived from a polyamide-forming component such as a substantially equimolar salt that satisfies the requirement of the amide group concentration as an essential component.

Examples of components for forming these polyamide resins include amino acids such as 11-aminoundecanoic acid, 12-aminododecanoic acid, and paraaminomethylbenzoic acid; lactams such as enantolactam and ω-laurolactam;
Tetramethylenediamine, hexamerenediamine, 2-
Methylpentamethylene diamine, nonamethylene diamine, decamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,4- / 2,4
4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, metaxylenediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1-amino-3 -Aminomethyl-3,5,5-trimethylcyclohexane, bis (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) propane, bis ( Aliphatic, alicyclic and aromatic diamines such as aminopropyl) piperazine and aminoethylpiperazine, and adipic acid, speric acid, azelaic acid, sebacic acid, dodecane diacid, isophthalic acid, 2-chloroterephthalic acid, 2-chloroterephthalic acid; Methyl terephthalic acid, 5-methyl isophthalic acid, - sodium sulfoisophthalic acid,
Examples thereof include aliphatic, alicyclic, and aromatic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid.

Among these, as the polyamide resin which is preferably used as the component (A), a polyamide resin in which the dicarboxylic acid component forming the amide structural unit is all terephthalic acid is exemplified.

Specific examples of the diamine component giving the amide structural unit include hexamerenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4 -/ 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane,
-Amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis (aminopropyl) piperazine,
Aminoethylpiperazine and the like.

Further, (A) preferably used in the present invention.
The polyamide resin as a component includes (a) a hexamethylene terephthalamide unit and (b) an aliphatic polyamide unit having 8 or more carbon atoms (amide group concentration) per amide group and / or (c) undecaneamide. And a unit composed of at least one structural unit selected from a unit, a dodecaneamide unit and a caproamide unit. The (a) hexamethylene terephthalamide unit is a unit synthesized from hexamethylene diamine and a derivative such as terephthalic acid or ester or acid halide, and the component (c) is ε-caprolactam, ω-laurolactam, ε- It is a unit derived from raw materials such as aminocaproic acid, 12-aminododecanoic acid, and 11-aminoundecanoic acid.

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 (b) include hexamethylene diammonium sebacate and hexamethylene diamine. Examples thereof include ammonium decanoate, hexamethylene diammonium dodecanoate, 12-aminododecanoic acid, ω-laurolactam, and 11-aminoundecanoic acid.

In the case of a two-component polyamide component, the components (a) and (b) are 75 to 45 mol% and 25 to 55 mol%, respectively. 75-45 mol% of each of the components (a)-(c), 50
In the present invention, it is necessary and important that the copolymer be contained at a ratio of 20 to 20 mol% and 5 to 15 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, and high dimensional stability upon water absorption can be exhibited. In particular, maintain a glass transition point of 40 ° C. or more during water absorption,
It is important that there is a segment having a loss elastic modulus peak of 80 ° C. or more.

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, and thermal stability is impaired, such as deterioration during melting, and 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 melting point is lowered, and the required heat resistance cannot be maintained, which is not preferable. Conversely, if it is smaller than the above range, the water absorption increases, It is not preferable because the rigidity is reduced. 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 and the required heat resistance cannot be maintained. This is not preferred because the fluidity of the resulting polyamide resin decreases and the significance of introducing the component (c) is reduced.

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% 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 salt) and a mixed aqueous solution of ε-caprolactam
The reaction is heated under a steam pressure of 40 kg / cm2, and then the melt polymerization is carried out while releasing the water in the system. Alternatively, the raw material aqueous solution is heated to 250 to 330 ° C. to form a prepolymer once. And a method of extruding a 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-based 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 which 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, a 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 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 50 to 0.01 μm, 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 when it is extracted 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.

The amount of phosphine generated by the red phosphorus used in the present invention (here, the amount of phosphine generated was determined by placing 5 g of red phosphorus in a container such as a test tube having an internal capacity of 500 mL in which nitrogen was 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)
× dilution ratio) The amount of phosphine generated is usually based on 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 due to molded products, etc. 100 ppm or less, preferably 50 p
pm or less, more preferably 20 ppm or less. Specific examples of preferred commercial products of red phosphorus include “NOVA EXCEL” 140 and “NOVA EXCEL” F manufactured by Rin Kagaku Kogyo Co., Ltd.
5 and the like.

As other non-halogen flame retardants, silicone flame retardants, low melting point glass, expandable graphite and the like can 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 fiber, carbon fiber, aramid fiber, potassium titanate fiber, metal fiber, ceramic fiber and the like. 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 a thermosetting resin, and treated with a silane-based, titanate-based coupling agent, or other 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, which is 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 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, weathering stabilizers (resorcinol, salicylate, benzotriazole, benzophenone, hindered amine, etc.), 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.

[0044]

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 differential working calorimeter manufactured by Seiko Electronics Industry Co., Ltd.

(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: 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 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) 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 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 unit and 50 mol% of dodecane amide unit 60% by weight) into a pressure polymerization kettle,
After raising the temperature under stirring and reacting at a steam pressure of 35 kg / cm2 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 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 2-7 A raw material was prepared so as to have the composition shown in Table 1, and 0.05% by weight of sodium hypophosphite was added to the solid content of the raw material. A raw material aqueous solution (solid raw material concentration: 60% by weight) was charged into a pressure polymerization vessel and heated under stirring. Keep the water vapor pressure at 35kg / cm2,
After reacting until the temperature inside the polymerization vessel reached the melting point temperature in Table 2,
While supplying the heated water to the polymerization vessel, the oligomer was discharged from the discharge port at the lower part of the polymerization vessel while maintaining the pressure in the polymerization vessel and the temperature in the polymerization vessel, and cooled in a cooling bath. The relative viscosity of the oligomer obtained here was in the range of 1.3 to 1.4.

The obtained oligomer was dried and pulverized, and then subjected to a 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 in the range of 2.4 to 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 8 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. 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.

[0055]

[Table 1]

Examples 1 to 6 and Comparative Examples 1 and 2 Red phosphorus ("NOVA EXCEL 14" manufactured by Rin Kagaku Kogyo Co., Ltd.) was used in an amount shown in Table 2 based on 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 summarizes 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 6 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 a small dimensional stability with a small molding shrinkage and a small water absorption dimensional change. It is a good composition and of high practical value.

[0059]

[Table 2]

[0060]

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. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08K 7/14 C08K 7/14 9/04 9/04

Claims (20)

[Claims] (A) An amide structural unit derived from an aliphatic or alicyclic diamine having 6 to 12 carbon atoms and terephthalic acid, and the number of carbon atoms per amide group (amide group concentration) Is 100 parts by weight of a polyamide resin having a melting point of 280 ° C. or more and less than 325 ° C., and 0.1 to 50 parts by weight of a non-halogen flame retardant (B). Polyamide resin composition. 2. The flame-retardant polyamide resin composition according to claim 1, wherein all of the dicarboxylic acid components forming the amide structural unit of the polyamide resin (A) are terephthalic acid. 3. The polyamide resin of component (A) is (a) an aliphatic having 75 to 45 mol% of hexamethylene terephthalamide units and (b) having 8 or more carbon atoms (amide group concentration) per amide group. 2. The flame-retardant polyamide resin composition according to claim 1, wherein the composition comprises 25 to 55 mol% of a polyamide unit, and the properties thereof are in the following ranges. (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 4. A polyamide resin as component (A) comprising: (a) 75 to 45 mol% of hexamethylene terephthalamide units;
(B ′) the number of carbon atoms per one amide group (amide group concentration) is 8 or more, and 50 to 20 mol% of an aliphatic polyamide unit not defined in the following component (c); and (c)
2. The difficulties according to claim 1, comprising 5 to 15 mol% of at least one type of structural unit selected from undecaneamide units, dodecaneamide units and caproamide units, and further having the following characteristics. Flammable polyamide resin composition. (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 5. The flame-retardant polyamide resin composition according to claim 3, 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 3, 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 4, wherein the polyamide unit of the component (c) is a caproamide unit. 8. The flame-retardant polyamide resin composition according to claim 4, wherein the polyamide unit of the component (c) is a dodecaneamide unit. 9. The flame-retardant polyamide resin composition according to claim 4, wherein the aliphatic polyamide unit of the component (b ′) is hexamethylene sebacamide and the polyamide unit of the component (c) is a caproamide unit. 10. The flame-retardant polyamide resin composition according to claim 4, wherein the aliphatic polyamide unit of the component (b ′) is hexamethylene sebacamide and the polyamide unit of the component (c) is a dodecaneamide unit. 11. The flame-retardant polyamide resin composition according to claim 1, wherein the polyamide resin (A) has a melting point in the range of 300 to 325 ° C. 12. The flame-retardant polyamide resin composition according to claim 1, wherein the non-halogen flame retardant (B) is a phosphorus-containing flame retardant. 13. The flame-retardant polyamide resin composition according to claim 12, wherein the non-halogen flame retardant (B) is red phosphorus. 14. The flame-retardant polyamide resin composition according to claim 13, wherein the component (B) non-halogen flame retardant is red phosphorus coated with a thermosetting resin. 15. 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. 16. The flame-retardant polyamide resin composition according to claim 15, wherein the inorganic filler (C) 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. The flame-retardant polyamide resin composition according to claim 1, further comprising (D) 0.1 to 50 parts by weight of a polyethylene terephthalate resin based on 100 parts by weight of the polyamide resin. 19. 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. 20. A molded article obtained by injection molding the flame-retardant polyamide resin composition according to claim 1.