JP3280103B2 - Flame retardant polyamide resin composition - Google Patents

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 with reduced gas generation during molding.

[0002]

2. Description of the Related Art Polyamide resins have been used in various fields such as automobile parts, electric / electronic parts, and mechanical parts, because of their good mechanical properties, moldability and chemical resistance.

Of these, there is a strong demand for flame retardancy in electric and electronic parts applications, and it is necessary to impart even higher flame retardancy to polyamide resins which are inherently self-extinguishing. A polyamide resin composition obtained by blending a flame retardant of melamine cyanurate with a polyamide resin is well known. (JP-A-53-31759, JP-A-53-31759)
No. 125549)

[0004]

However, this polyamide resin composition has a narrow molding range and a longer residence time, or as the resin temperature at the time of molding increases, gas is generated, and the surface of the molded article is reduced. There was a problem that the appearance deteriorated.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the above-mentioned object has been achieved by adding a specific copper compound and potassium iodide to a specific polyamide resin. And found that the present invention was completed.

[0006] Flame-retardant polyamide resin compositions to which a copper compound has been added are known. That is, JP-A-53-10465.
No. 5 discloses addition of a copper compound. However, the purpose of the invention disclosed in the publication is to improve the tensile strength retention after the heat aging test and to improve the color tone of the test piece, and there is no disclosure about gas reduction during molding.

[0007] It is an object of the present invention to provide a flame-retardant polyamide resin composition with reduced gas generation during molding. That is, in the present invention, the terminal amino group ratio is 50 to 90.
% Of the polyamide resin (100 parts by weight), (1)
Melamine cyanurate 1 to 20 parts by weight, (2) copper compound 0.0003 to 0.0099 parts by weight as copper content, (3) potassium iodide Flame retardant polyamide resin containing 5 to 50 in molar ratio of iodine to copper A composition.

Hereinafter, the present invention will be described in detail. The polyamide resin used in the present invention has an amino terminal group concentration ratio (amino terminal group concentration / amino terminal group concentration + carboxyl terminal group concentration) of 50 to 90% containing amino acid, lactam or diamine and dicarboxylic acid as main components. Is a polyamide resin.

Specific examples of the constituent components include lactams such as ε-caprolactam, enantholactam and ω-laurolactam; amino acids such as ε-aminocaproic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid;

[0010] Tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, m-xylylenediamine , P-xylylenediamine, 1,3-bisaminomethylcyclohexane, 1,4
Diamines such as -bisaminomethylcyclohexane, bis-p-aminocyclohexylmethane, bis-p-aminocyclohexylpropane, isophoronediamine;

Adipic acid, suberic acid, azelaic acid,
Sebacic acid, dodecane diacid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid,
There are dicarboxylic acids such as dimer acids.

These constituents are subjected to polymerization alone or in the form of a mixture of two or more, and any of the polyamide homopolymers and copolymers thus obtained can be used in the present invention.

Particularly useful polyamides useful in the present invention are polycapramid (nylon 6), polyhexamethylene adipamide (nylon 66), polytetramethylene adipamide (nylon 46), and polyhexamethylene sebacamide (nylon). 610), polyundecaneamide (nylon 11), polydodecaneamide (nylon 12), polyhexamethylene adipamide / hexamethylene terephthalamide copolymer (nylon 66 / 6T), polycapramid / polyhexamethylene adipamide copolymer Combined (nylon 6/66) and mixtures of these polyamides.

When the terminal group concentration ratio of the polyamide resin is from 50 to
It can be easily adjusted to 90% by adding a monoamine or diamine compound or a derivative thereof.

The monoamine and diamine compounds include, for example, methylamine, ethylamine, propylamine, isopropylamine, hexamethylenediamine, piperazine, N-aminopentylpiperazine, N, N'-diaminopentylpiperazine, N-aminopropylmorpholine, Methylene diamine, undecamethylene diamine, dodecamethylene diamine,

2,2,4- / 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, m-xylylenediamine, p-xylylenediamine, 1,3-bisaminomethylcyclohexylpropane, Bis-p-aminocyclohexylpropane, isophoronediamine, stearylamine and their derivatives are used.

The amine compounds may be used alone or in combination of two or more. The addition time of these terminal group concentration regulators may be added at any stage before, during or after the polymerization.

The amino terminal group concentration ratio in the polyamide resin is preferably from 50 to 90%, and particularly preferably.
55-85%. When the amino terminal group concentration ratio is less than 50%, it is difficult to obtain the effect of reducing gas generation during molding, and the polymerization of the polyamide to be more than 90% tends to be inhibited.

The melamine cyanurate used in the present invention is an equimolar reaction product of cyanuric acid and melamine,
For example, it can be obtained by mixing an aqueous solution of cyanuric acid and an aqueous solution of melamine, reacting the mixture at a temperature of about 90 to 100 ° C. with stirring, and filtering the generated precipitate.

This is a white solid, and is preferably used by pulverizing it into a fine powder. Of course, a commercially available product can be used as it is or after being pulverized. Also, some of the amino groups or hydroxyl groups in melamine cyanurate,
It may be substituted with another substituent.

The amount of melamine cyanurate used is 1 to 20 parts by weight, preferably 3 to 15 parts by weight. Use of more than 20 parts by weight of melamine cyanurate will reduce the mechanical properties. If the amount is less than 1 part by weight, a sufficient flame retardant effect cannot be expected.

Examples of the copper compound used in the present invention include salts of inorganic acids such as copper chloride, copper bromide, copper iodide, copper sulfate, copper nitrate and copper phosphate, or copper acetate, copper stearate, mystyrin Organic acid salts such as copper acid copper, copper naphthenate and copper palmitate may be mentioned, and two or more of these may be used in combination.

Among the above copper compounds, copper acetate and copper iodide are preferred. The amount used is 0.0003 to 0.0099 as copper content
Parts by weight, preferably 0.001 to 0.008 parts by weight.

If the amount is less than 0.0003 parts by weight, the effect of suppressing gas generation is not recognized, and if it exceeds 0.0099 parts by weight, discoloration is not preferred. The amount of potassium iodide used in the present invention is such that the molar ratio of iodine to copper is 10 to 3;
0 is preferred.

The addition time of the copper compound and potassium iodide is not particularly limited, and they can be added at any stage before, during or after the polymerization. The method of blending the flame retardant, copper compound and potassium iodide with the polyamide is not particularly limited. Examples thereof include a method of adding during the polymerization of polyamide, a method of simply mixing polyamide pellets, a flame retardant powder, a copper compound and potassium iodide, and melt-kneading them with a twin-screw extruder.

To the polyamide resin composition of the present invention, other additives such as a lubricant, an antistatic agent, a weathering agent, a reinforcing agent and the like are added in an appropriate amount at any stage so as not to significantly impair the effects of the present invention. can do.

[0027]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples. (Evaluation method) The weight loss of the pellet was measured by TGA-50 manufactured by Shimadzu Corporation. The larger the weight loss, the more gas is generated, and the worse the moldability is.

The measurement conditions were as follows, under an atmosphere of air 20 cc / min.
STep1: 99.9 ° C / min up to 277 ° C, STep2: 2
Up to 298 ° C at 5 ° C / min, Step 3: 30 ° C at 1 ° C / min.
The test was performed using a three-step heating program in which the temperature was raised to 0 ° C.
The ratio of weight loss after 12 minutes and 30 minutes after reaching 300 ° C. is compared.

(Comparative Example 1) An aqueous solution of hexamethylenediamine / adipic acid was placed in a polymerization vessel, and after purging with nitrogen, polymerization was carried out according to a usual polymerization method. .

The pellets were vacuum dried at 80 to 100 ° C. for 16 hours. 6.4 parts by weight of melamine cyanurate was mixed with 100 parts by weight of the dried pellets, and
The mixture was melt-kneaded with a CH45 twin-screw extruder, and the strand was cooled and then pelletized with a pelletizer to obtain a polyamide resin composition. The pellets obtained here were dried at 80 to 100 ° C. under vacuum for 16 hours, and the weight loss was evaluated.

Comparative Example 2 The same operation as in Comparative Example 1 was conducted except that 0.8% of hexamethylenediamine as a terminal regulator was added to hexamethylenediamine adipate and polymerized in a polymerization vessel. evaluated.

(Comparative Example 3) Evaluation was made in the same manner as in Comparative Example 1 except that hexamethylenediamine adipate was polymerized by putting 1.1% of hexamethylenediamine as a terminal regulator into a polymerization kettle. did.

(Examples 1 to 5) Melamine cyanurate, copper acetate, copper iodide, and potassium iodide were mixed with the polymerized pellets obtained in Comparative Examples 2 to 3 in predetermined amounts shown in Table 1. , Melt-kneaded, and evaluated in the same manner as in Comparative Example 1.

Comparative Examples 4 and 5 Melamine cyanurate, copper acetate, copper iodide, and potassium iodide were mixed with the polymerized pellets obtained in Comparative Example 1 in predetermined amounts shown in Table 1.
The mixture was melted and kneaded and evaluated in the same manner as in Comparative Example 1. Tables 1 and 2 show the results of Examples 1 to 5 and Comparative Examples 1 to 5.

[0035]

[Table 1]

[0036]

[Table 2]

(Note) * In the amount of copper compound added (Cu = 15), copper conversion is 1
Indicates 5 ppm. * Amino (NH ₂ ) end group concentration and carboxyl (COO
H) Unit of concentration of terminal group is commonly used mg equivalent
/ Kg polymer . Comparative Examples 1 to 3 and Examples 1 to 5 show that the addition of the copper compound and potassium iodide has an effect of suppressing weight loss.
Further, from Comparative Examples 4 and 5, and Examples 1 and 3, it can be seen that the effect of suppressing gas generation cannot be obtained when the terminal ano group ratio is reduced.

[0038]

Industrial Applicability The composition of the present invention is a material having reduced gas generation and excellent moldability as compared with a polyamide resin composition having a terminal amino group ratio of less than 50%.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 77/00-77/12

Claims (1)

(57) [Claims] (1) 100 parts by weight of a polyamide resin having a terminal amino group ratio of 50 to 90%, (1) 1 to 20 parts by weight of melamine cyanurate, (2) copper compound The copper content is 0.0003 to 0.0099 parts by weight as copper content. Part, (3) Potassium iodide 5 molar ratio of iodine to copper
Polyamide resin composition containing 50 to 50.