JP2001081317A - Flame retardant polyamide resin composition and its molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame retardant polyamide resin composition excellent in discoloration resistance and mechanical properties even in environments of a high-temperature atmosphere and ultraviolet exposure. SOLUTION: This flame retardant polyamide resin composition is obtained by further including an inorganic pigment in an amount of 1-30 pts.wt. based on 100 pts.wt. of a polyamide resin, a phosphorus compound in an amount of 0.0005-0.2 pt.wt. based on 100 pts.wt. of the polyamide resin and expressed in terms of phosphorus element, a copper compound in an amount of 0.0001-0.05 pt.wt. based on 100 pts.wt. of the polyamide resin and expressed in terms of copper element and a halogen compound in an amount so as to provide the molar amount of a halogen element of 5-30 times based on the molar amount of the copper element in the flame retardant polyamide resin composition prepared by including a flame retardant in an amount of 1-100 pts.wt. based on 100 pts.wt. of the polyamide resin therein.

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 suitable for parts such as lighting fixtures exposed to a severe environment of high temperature atmosphere and exposure to ultraviolet rays.

[0002]

2. Description of the Related Art Polyamide resins have excellent mechanical properties,
Since it has heat resistance, chemical resistance, dimensional stability, flame retardancy, moldability, etc., it is used in a wide range of applications as an engineering resin. In particular, a flame-retardant polyamide resin molded article in which a flame retardant is blended with a polyamide resin is widely used for automobile electric parts and electric / electronic equipment parts due to its excellent flame retardancy. However, the polyamide resin has a problem that it is inferior in discoloration resistance as compared with a general-purpose resin such as polypropylene when used in an environment exposed to ultraviolet rays in outdoor parts or the like, and has been difficult to use so far.

Various techniques for improving the light discoloration resistance of polyamide resins have been proposed so far. For example, JP-A-2
Japanese Patent No. 229853 discloses a power supply component material having improved heat resistance and light resistance by a polyamide resin composition comprising a polyamide resin, an inorganic filler, titanium dioxide, a hindered phenol-based antioxidant, and an organic phosphorus-based stabilizer. A polyamide resin composition has been proposed. In addition, various techniques for improving the heat-resistant discoloration of polyamide resins have been proposed. For example, JP-A-6-157902 proposes a polyamide resin composition having improved heat resistance by a polyamide resin composition comprising a polyamide resin, a copper-based stabilizer, titanium oxide, and an inorganic filler. However, in these proposals, mechanical properties and discoloration resistance under conditions of heat treatment alone or light irradiation alone are improved to some extent, but under a more severe combined environment of high heat and ultraviolet irradiation in applications such as lighting equipment. Cannot be sufficiently satisfied.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a flame-retardant polyamide resin composition having excellent discoloration resistance and mechanical properties even in a high-temperature atmosphere and a severe environment exposed to ultraviolet rays. is there.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific polyamide resin composition can achieve the above-mentioned problems, and have reached the present invention. That is, the present invention is as follows. (1) 1 to 1 part by weight of a flame retardant per 100 parts by weight of polyamide
A flame-retardant polyamide resin composition containing 00 parts by weight, further comprising 1 to 30 parts by weight of an inorganic pigment, 0.0005 to 0.2 parts by weight of a phosphorus compound as a phosphorus element, and a copper compound as a copper element. 0.0001 to 0.05 parts by weight of the halogen compound, the molar amount of the halogen element is 5 times the molar amount of the copper element.
A polyamide resin composition comprising an amount of up to 30 times.

(2) The polyamide resin composition according to (1), wherein the inorganic pigment is titanium dioxide. (3) The polyamide resin composition according to (1) or (2), wherein the phosphorus compound is one or more phosphorus compounds selected from hypophosphorous acid, phosphorous acid, phosphoric acid, and metal salts thereof. object. (4) The polyamide resin composition according to (1) or (2), wherein the phosphorus compound is a phosphite compound.

(5) The polyamide resin composition according to any one of (1) to (4), wherein the copper compound is copper acetate and / or copper iodide. (6) The polyamide resin composition according to any one of (1) to (5), wherein the halogen compound is potassium iodide and / or potassium bromide. (7) 1 to 1 part by weight of flame retardant per 100 parts by weight of polyamide
A flame-retardant polyamide resin composition containing 00 parts by weight, further comprising 1 to 30 parts by weight of an inorganic pigment, 0.0005 to 0.2 parts by weight of a phosphorus compound as a phosphorus element, and 0 to 0 parts of a copper compound as a copper element. 0.0001 to 0.05 parts by weight of the halogen compound, the molar amount of the halogen element is 5 to the molar amount of the copper element.
What is claimed is: 1. A polyamide resin molded product comprising a polyamide resin composition containing a 30-fold amount, and having a degree of color change ΔE <25 after irradiation with a 400 watt mercury lamp in an atmosphere at 120 ° C. for 7 days.

Hereinafter, the contents of the present invention will be described in detail. The polyamide resin constituting the composition of the present invention may be a known one. For example, various types of polyamides such as a polycondensate of lactam, a polycondensate of a diamine compound and a dicarboxylic acid compound, and a polycondensate of ω-aminocarboxylic acid may be used. For example, nylon 6, nylon 66, nylon 61
0, nylon 6I, nylon 6T and the like, and their copolymerized polyamides, for example, nylon 66/6, nylon 66/610, nylon 66 / 6I, nylon 66 /
6T, etc., and their mutual blends.

The flame retardant used for the flame-retardant polyamide resin of the present invention includes various ones. Representative examples are brominated polystyrene, decabromodiphenyl oxide, halogen-based flame retardants such as perchlorocyclopentadecane, melamine, cyanuric acid, triazine-based flame retardants such as melamine cyanurate, red phosphorus, phosphorus-based materials such as ammonium polyphosphate and the like. Flame retardants, inorganic flame retardants such as antimony oxide, magnesium hydroxide, zinc borate and the like are used. These flame retardants may be used alone or in combination. These flame retardants are usually added in an amount of 1 to 100 parts by weight based on 100 parts by weight of the polyamide resin. Usually, these flame retardants are melt-kneaded with polyamide resin pellets using an extruder to produce flame-retardant polyamide resin pellets.

The inorganic pigments constituting the polyamide resin composition of the present invention include titanium dioxide, carbon black,
Iron oxide, ultramarine and the like can be used. These may be used alone or in combination. Particularly, titanium dioxide is most preferable for use in white resin parts such as lighting equipment. The titanium dioxide used in the present invention is not particularly limited in particle size, and may be either rutile or anatase in crystalline form. Also, Mn,
Compounds such as Al, Zn, and Si may be coated on the titanium oxide surface. These inorganic fillers are added in an amount of 1 to 30 parts by weight based on 100 parts by weight of the polyamide resin. When the amount is less than 1 part by weight, the effect of preventing discoloration in a high-temperature atmosphere and in a more severe environment under ultraviolet irradiation is insufficient, and when the amount is more than 30 parts by weight, there is a concern that mechanical properties are deteriorated.

As the phosphorus compound constituting the composition of the present invention, inorganic and organic phosphorus compounds can be used. Examples of the inorganic phosphorus compound include hypophosphorous acid, phosphorous acid, phosphoric acid, and metal salts thereof. Examples of the metal species include alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium, and manganese. Preferred are sodium salts of hypophosphorous acid,
And sodium salts of phosphorous acid.

Examples of organic phosphorus compounds include bis (2,
6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite (trade name ADK STAB P
EP-36 (hereinafter referred to as PEP-36)), tris (2,4-di-t-butylphenyl) phosphite (trade name IRGAFOS-168), 2-[[2,4,8,
10 Tetrakis (1,1-dimethylethyl) dibenzo [d, f] [1,3,2] dioxaphosphepin-6
-Yl] oxy] -N, N-bis [2-[[2,4,
8,10 tetrakis (1,1-dimethylethyl) dibenzo [d, f] [1,3,2] dioxaphosphepin-
6-yl] oxy] -ethyl] ethanamine (trade name IR
GAFOS-12), distearyl-pentaerythritol-diphosphite (trade name: ADK STAB PEP-
8), bis (2,4-di-t-butylphenyl) pentaerythritol-di-phosphite (trade name: Adekastab PEP-24G), 2,2-methylenebis (4,6-
Phosphite compounds such as di-t-butylphenyl) octyl phosphite (trade name: ADK STAB HP-10), trimethyl phosphite, triethyl phosphite, triphenyl phosphite; tetrakis (2,4-di-t-butylphenyl) ) Phosphonite compounds such as 4,4'-biphenylylene-di-phosphonite (trade name Sandstab P-EPQ), phosphate compounds such as trimethyl phosphate and triethyl phosphate, phenylphosphonic acid, phenylphosphinic acid and the like. Of these, phosphite compounds are preferred. These inorganic and organic phosphorus compounds may be used alone or in combination.

The phosphorus compound is added in an amount of 0.001 parts by weight of the phosphorus compound to 100 parts by weight of the polyamide resin.
It is 0.5 to 0.2 parts by weight. When the amount is less than 0.0005 parts by weight, the effect of preventing discoloration in a high temperature atmosphere and under a more severe environment under ultraviolet irradiation is insufficient, and when the amount is more than 0.2 parts by weight, the polyamide compound melts due to the thickening effect of the phosphorus compound. The viscosity may increase, which may hinder molding.
As the copper compound constituting the composition of the present invention, copper acetate,
Examples thereof include copper iodide, copper bromide, copper chloride, copper fluoride, copper laurate, and copper stearate. These copper compounds may be used alone or in combination. Copper acetate and copper iodide are particularly preferably used. The addition amount of the copper compound is 0.0001 to 0.05 parts by weight as the copper element in the copper compound based on 100 parts by weight of the polyamide resin.
When the amount is less than 0.0001 part by weight, the effect of preventing discoloration in a high temperature atmosphere and under a more severe environment under ultraviolet irradiation is insufficient, and when the amount is more than 0.05 part by weight, the effect of preventing discoloration under the severe environment is leveled off. Further, there is a concern that problems such as corrosion of a mold, a screw or a cylinder of an extruder or a molding machine may occur.

When a copper compound is added, a halogen compound is usually used in combination. As examples of the halogen compound, potassium iodide and potassium bromide are preferable. The molar amount of the halogen compound is 5 to 30 times the molar amount of the copper element of the copper compound. If the addition amount of the halogen compound is out of this range, the screw of the extruder or the molding machine, the cylinder, etc. may be corroded,
It is not preferable because coloring occurs.

The method of adding the inorganic pigment, phosphorus compound, copper compound and halogen compound constituting the present invention may be added at any stage of the production of the polyamide, and the method of addition is not limited. For example, a method of adding to a raw material salt aqueous solution of a polyamide, a method of injecting and adding into a molten polyamide in the course of melt polymerization, after blending a polyamide pellet and a powder or a master batch of the additive after finishing polymerization and granulating. Any method such as melt kneading using an extruder or a molding machine may be used.

The inorganic filler, the inorganic pigment, the phosphorus compound, the copper compound and the halogen compound of the present invention may be mixed together and added simultaneously in desired steps, or may be added in separate steps. May be. In addition, the polyamide composition of the present invention includes glass filler, talc, wollastonite and other inorganic fillers, hindered amine-based or hindered phenol-based oxidants that are commonly used in polyamides as long as the object of the present invention can be achieved. Inhibitors, heat stabilizers,
Known substances such as a sulfur-based antioxidant, a coloring agent, and a lubricant can be further contained.

Further, the present invention is a molded article comprising the polyamide resin composition described in detail above. That is,
The molded article of the present invention is based on 100 parts by weight of polyamide.
1 to 100 parts by weight of a flame retardant, 1 to 30 parts by weight of an inorganic pigment, 0.0005 to 0.2 parts by weight of a phosphorus compound as a phosphorus element, 0.0001 to 0.05 parts by weight of a copper compound as a copper element, The polyamide resin composition contains a halogen compound in an amount such that the molar amount of the halogen element is 5 to 30 times the molar amount of the copper element. Examples of molded articles include sockets, switches, cases, covers, and the like, injection molded articles used as electric and electronic parts, automobile interior and exterior parts, automobile electric parts, etc., extruded molded articles such as round bars, pipes, and bottles. Blow molded articles are exemplified. By molding the molded body using the polyamide resin composition of the present invention, the degree of discoloration in a 7-day exposure test under a 400-watt mercury lamp atmosphere at 120 ° C. can be set to ΔE <25. ΔE ≧
In the case of No. 25, yellowing coloring is conspicuous, so that the appearance of the molded article is impaired, and there is a concern that the product value is reduced.

[0018]

EXAMPLES Examples and comparative examples are given below.
The present invention will be described more specifically, but the present invention is not limited by these examples. In addition, the evaluation method is as follows. (1) Method for preparing an evaluation test piece Using a PS40E injection molding machine manufactured by Nissei Plastic Industry Co., Ltd.,
Cylinder temperature 280 ° C, mold temperature 80 ° C, injection pressure 3
A molded article of ASTM-D638 Type 1 was prepared under a molding condition of 0 kg / cm ² gauge pressure and an injection speed of 40%, and this was used as a test piece. (2) Mercury lamp exposure test The test piece was left for 7 days in a mercury lamp exposure tester in which the temperature in the bath was adjusted to 120 ° C. The mercury lamp irradiation tester is provided with a 400 W mercury lamp and a rotating sample table in a tank of a gear oven GPH-200 manufactured by Tabai Espec Co., Ltd. (3) Discoloration degree A color difference meter ND-300A manufactured by Nippon Denshoku Industries Co., Ltd. was used.
L of each test piece before and after the exposure test
A color difference ΔE as a criterion for judging discoloration resistance by an exposure test was determined from the values, a values, and b values. When the value of ΔE is small, discoloration is small, indicating that the discoloration resistance is more excellent. (4) Tensile strength Using the test piece after the exposure test, ASTM-D638
The tensile strength at break was determined in accordance with. (5) Flame retardant UL94 (Under Writers Labo, USA)
ratifications Inc.). The test piece was prepared using a PS40E molding machine.
One having a thickness of / 16 inch was prepared.

[0019]

Example 1 A 50% by weight aqueous solution of an equimolar salt of adipic acid and hexamethylenediamine (hereinafter referred to as AH salt) 5k
g in a 5 liter autoclave, and copper acetate as a copper compound and potassium iodide as a halogen compound were added to each of 0.0100 parts by weight of the polymer.
2 parts by weight (0.0064 parts by weight of copper element) and 0.20 parts by weight (the molar amount of the halogen element is
X) was added. After the inside of the autoclave was replaced with nitrogen, the autoclave was heated to 280 ° C., the internal pressure of the autoclave was controlled at a gauge pressure of 18 kg / cm ² , and the reaction was carried out for 85 minutes while removing water from the reaction system. The pressure was reduced to atmospheric pressure, and the mixture was allowed to stand for 60 minutes and then cooled to obtain a nylon 66 resin.

The obtained nylon 66 resin is pulverized, and 100 parts by weight of nylon 66 resin are mixed with 7 parts by weight of melamine cyanurate as a flame retardant, 5 parts by weight of titanium dioxide as an inorganic pigment, and PEP as a phosphorus compound. -36 is added and blended with 0.31 part by weight (0.03 part by weight of phosphorus element), and a twin screw extruder TEM3 manufactured by Toshiba Machine Co., Ltd. is used.
The resulting mixture was melt-kneaded at a temperature of 290 ° C. at 5 to form pellets.
The obtained pellets were molded using the PS40E, and an exposure test was performed on the obtained test pieces to determine the degree of discoloration and the tensile strength. The obtained pellets were also evaluated for flame retardancy. Table 1 shows the evaluation results.

[0021]

Examples 2-3 and Comparative Examples 1-2 In Example 1, the types and amounts of flame retardants, inorganic pigments, phosphorus compounds, copper compounds, halogen compounds and other compounding agents were changed as shown in Table 1. A polyamide resin composition pellet was obtained in the same manner as in Example 1. The obtained pellets were evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.

[0022]

[Table 1]

The abbreviations in Table 1 are as follows. PA66: nylon 66 MC: melamine cyanurate Br-PS: brominated polystyrene Sb ₂ O _3: Antimony trioxide TiO _2: Titanium dioxide PEP-36: manufactured by Asahi Denka Co., Ltd. Stab PEP-36 NP: hypophosphorous acid Sodium monohydrate KI: Potassium iodide GF: Glass fiber (about 10 μm in diameter, about 3 mm in length)

[0024]

The flame-retardant polyamide resin composition of the present invention and the molded article made therefrom have the following remarkable effects because they are constituted as described above in detail. 1. The flame-retardant polyamide resin composition according to the present invention contains a specific inorganic pigment, a phosphorus compound, a copper compound, and a halogen compound. Also, the deterioration of mechanical properties over time and the progress of discoloration over time are extremely small. That is, the heat resistance and light resistance over time are remarkably excellent. 2. In addition, since it is a polyamide resin composition to which a specific amount of a phosphorus compound, a copper compound, and a halogen compound are added, it exhibits a melt viscosity suitable for injection molding or the like, and also does not cause corrosion to a molding machine screw or the like, Excellent moldability. 3. Accordingly, when the molded article made of the flame-retardant polyamide resin composition of the present invention is used as a part for a lighting fixture or the like which is exposed to high-temperature atmosphere and strong ultraviolet rays for a long period of time, its appearance is remarkable with time. There is no risk that it will be damaged or its value will drop sharply.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08K 5/098 C08K 5/098 5/3477 5/3477 5/524 5/524 F term (reference) 4F071 AA54 AA55 AB15 AB25 AC09 AC15 AC19 AE07 AE09 AF15 AF34 AF47 AF57 AH07 AH12 BA01 BB05 BC00 4J002 BC112 CL011 CL031 CL051 DA037 DA056 DD059 DD079 DD089 DE076 DE117 DE126 DE137 DH038 DH046 DH048 DK006 EB086 EB136 FD080 EW 010 148

Claims (7)

[Claims] 1. A flame-retardant polyamide resin composition comprising 1 to 100 parts by weight of a flame retardant per 100 parts by weight of a polyamide, further comprising 1 to 30 parts by weight of an inorganic pigment,
0.0005 to 0.2 parts by weight of a phosphorus compound as a phosphorus element,
A polyamide resin composition comprising 0.0001 to 0.05 parts by weight of a copper compound as a copper element and a halogen compound in an amount such that the molar amount of the halogen element is 5 to 30 times the molar amount of the copper element. . 2. The polyamide resin composition according to claim 1, wherein the inorganic pigment is titanium dioxide. 3. The polyamide resin according to claim 1, wherein the phosphorus compound is one or more phosphorus compounds selected from hypophosphorous acid, phosphorous acid, phosphoric acid and metal salts thereof. Composition. 4. The polyamide resin composition according to claim 1, wherein the phosphorus compound is a phosphite compound. 5. The polyamide resin composition according to claim 1, wherein the copper compound is copper acetate and / or copper iodide. 6. The polyamide resin composition according to claim 1, wherein the halogen compound is potassium iodide and / or potassium bromide. 7. A flame-retardant polyamide resin composition containing 1 to 100 parts by weight of a flame retardant based on 100 parts by weight of a polyamide, further comprising 1 to 30 parts by weight of an inorganic pigment and a phosphorus compound as a phosphorus element. 0.0005 to 0.2 parts by weight, 0.0001 to 0.05 parts by weight of a copper compound as a copper element,
A halogen compound is a polyamide resin composition containing a molar amount of a halogen element that is 5 to 30 times the molar amount of a copper element. 25. A polyamide resin molded product comprising: