JPH11302536A - Frame-retardant polyamide resin molding composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject molding composition excellent in flame retardance property and moldability and improved in mechanical property esp. tensile elongation at break. SOLUTION: This molding material is produced by blending flame-retardant polyamide resin composition particles obtained by meltingly kneading (a) polyamide resin, (b) melamine cyanurate and (c) at least one surface active agent selected from polyalkylene polyalcohol and its fatty acid ester with polyamide resin particles. In this case, the molded products derived from the molding composition contains 1 to 20 wt.% of (b) melamine cyanurate and 0.01 to 2 wt.% of (c) surface active agent.

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 improved physical properties, and more particularly to a flame-retardant polyamide resin composition having excellent flame retardancy and moldability, as well as mechanical properties, particularly tensile elongation at break. The present invention relates to a flame-retardant polyamide resin molding material having an improved degree.

[0002]

2. Description of the Related Art Polyamide resins are used in various fields such as automobile parts, electric / electronic parts, etc., utilizing their excellent mechanical properties, electrical properties, chemical resistance, moldability and the like. Among these, flame-retardant polyamides are widely used in fields requiring a high degree of flame retardancy, such as electric and electronic parts. Among them, flame-retardant polyamide resins containing melamine cyanurate are known. (JP-A-53-1)
No. 25459, JP-A-53-31759).

When the flame retardancy is improved by blending melamine cyanurate as described above, the blending amount of melamine cyanurate is generally in the range of 1 to 10% by weight, and as the blending amount increases, the flame retardancy improves. I do. However, when blended in a large amount, the dispersibility of the melamine cyanurate in the polyamide resin is significantly deteriorated. Therefore, the flame-retardant polyamide resin containing such a flame retardant is more mechanical than the one containing no flame retardant. It has the disadvantage of poor properties. Therefore, in applications such as electric and electronic parts that require particularly high material reliability, improvements in mechanical properties such as tensile elongation are desired.

[0004] On the other hand, as a method for improving the dispersion state of meamine cyanurate in a polyamide resin to prevent a decrease in mechanical properties, a master batch obtained by melt-kneading a polyamide resin and melamine cyanurate and a polyamide resin are melt-kneaded. A method (for example, JP-A-08-245875) is known. However, in such a method, melamine cyanurate in the polyamide resin is decomposed into melamine and cyanuric acid by thermal decomposition due to the two-stage kneading, and is easily sublimated. Under the influence of the sublimated melamine and cyanuric acid, silver is generated on the surface of the molded product during molding and the surface of the mold is easily contaminated. In addition, the dispersibility of melamine cyanurate cannot be said to be sufficient, and there are drawbacks in that irregularities occur on the surface of the molded product and the weld portion has low elongation.

On the other hand, melamine cyanurate is coated on the surface to prevent aggregation of melamine cyanurate itself, thereby improving dispersibility and improving mechanical properties (for example, JP-A-06-157820). It has been known. However, such a method has a problem that the cost is relatively high and the coated melamine cyanurate bleeds out to the surface of the molded article or the flame retardancy is impaired.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a flame-retardant polyamide resin molding material which is excellent in flame retardancy and moldability and has improved mechanical properties, especially tensile elongation at break. is there.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies and as a result, have found that flame-retardant polyamide resin granules mainly composed of polyamide resin, melamine cyanurate and a specific surfactant, and polyamide resin granules. It has been found that a molding material in which is mixed can achieve the object, and based on this finding, the present invention has been completed. That is, the present invention
(A) A flame-retardant polyamide resin obtained by melt-kneading a polyamide resin (A), melamine cyanurate (B), and at least one surfactant (C) selected from polyalkylene polyhydric alcohols or fatty acid esters thereof. (C) a flame-retardant polyamide resin molding material obtained by mixing a composition granule and (B) a polyamide resin granule,
The molded product obtained from the flame-retardant polyamide resin molding material has a melamine cyanurate content of 1 to 20% by weight and a surfactant (C) content of 0.01 to 2% by weight. It is a flame-retardant polyamide resin molding material.

Hereinafter, the present invention will be described in detail. In the present invention, the flame-retardant polyamide resin composition granules (A)
It is obtained by melt-kneading a polyamide resin (a), melamine cyanurate (b) and a surfactant (c). The polyamide resin (a) used for the granules includes polylactams such as nylon 6, 11, 12, and the like;
Polyamides obtained by polycondensation of diamines such as 6, 46, 610, 612 and dicarboxylic acids, nylon 6
/ 66 copolymer, hexamethylene terephthalamide unit (6T), hexamethylene isophthalamide unit (6T)
Nylon 6T / 66 copolymer having I), nylon 6
I / 66 copolymer, nylon 6T / 6I copolymer and the like, but nylon 66, nylon 6, nylon 66 /
6, using nylon 6I / 66, heat resistance, flame retardancy,
From the viewpoint of moldability, more effects can be expected.

The melamine cyanurate (b) used in the present invention is an equimolar reaction product of melamine and cyanuric acid. For example, an aqueous solution of melamine and cyanuric acid is stirred in water at about 90 to 100 ° C. Then, the precipitate obtained as a reaction product is filtered and dried, and then pulverized to a fine powder. Since such melamine cyanurate is commercially available, an industrially available substance is used. can do.

The surfactant (c) used in the present invention is:
Polyethylene glycol, polypropylene glycol,
Polyalkylene glycols such as polybutylene glycol and these glycols, capric acid, lauric acid,
Myristic acid, palmitic acid, stearic acid, behenic acid, cerotic acid, montanic acid, melicic acid, oleic acid, ester derivatives with aliphatic carboxylic acids such as erucic acid, but are easily available industrially, Particularly effective substances include polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol distearate, polyethylene glycol monooleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate, and polyoxyethylene. Ethylene sorbitan tristearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbita Monostearate, polyoxyethylene sorbitan monooleate is preferably used.

[0011] Flame-retardant polyamide resin composition granules (A)
Melamine cyanurate in the, there is no particular limitation on the content of the surfactant, the melamine cyanurate in the molded product obtained by molding the finally obtained flame-retardant polyamide resin molding material is 1 to 20 weight %, Surfactant is 0.1%.
It is blended so as to be able to contain from 0.1 to 2% by weight,
The content of melamine cyanurate in the granules is 2 to 6.
0% by weight, especially 3 to 50% by weight is preferred. When the melamine cyanurate content is 2% by weight or less, there is no flame retardant effect, and when it is 60% by weight or more, the cohesive strength of the composition is reduced, and not only there are production problems such as strand breakage during production, but also the dispersibility is poor. The deterioration is remarkable, and a decrease in mechanical properties is likely to occur. On the other hand, the content of the surfactant in the granular material (A) is usually 0.02 to 30% by weight, particularly 0.03 to 30% by weight.
5% by weight is preferred. When the amount of the surfactant is 0.02% or less, there is no effect on the dispersibility of melamine cyanurate, and when the amount is 30% by weight or more, the flame retardancy is adversely affected.

The flame-retardant polyamide resin composition granules (A) can be produced by any known method. Melt cyanurate and a surfactant are melt-mixed with the polyamide resin by an extruder or the like, and the strands are prepared. Examples include a method of granulating by cooling, cutting, and granulating, and a method of blending melamine cyanurate and a surfactant in a polyamide-forming monomer, performing condensation polymerization, forming a strand, cooling, cutting, and granulating. Can be. Here, the granular material indicates a general shape used for injection molding or extrusion molding, and does not limit the shape. In other words, the granular material may be a columnar material having a diameter of about 3 mm and a length of about 3 mm, or a powder having an average particle diameter of 300 μm. The flame-retardant polyamide resin composition granules (A) may contain a usual lubricant and a moldability improver in the polyamide resin.

The surfactant (c) in the granules is mixed with the flame-retardant polyamide resin composition granules (A).
It may be blended with the polyamide resin granules or mixed with the granules at the time of molding, but it is blended with the flame-retardant polyamide resin composition granules (A), and further blended with the polyamide resin granules (B). Then, the dispersing effect is further manifested.

In the present invention, the granular polyamide resin (B) is obtained by polycondensation of a polylactam such as nylon 6, 11, 12 or the like, or a diamine and a dicarboxylic acid such as nylon 66, 46, 610 or 612. Polyamide, nylon 6/66 copolymer, nylon 6T / 66 copolymer having hexamethylene terephthalamide unit (6T), hexamethylene isophthalamide unit (6I), nylon 6I / 66 copolymer, nylon 6T /
6I copolymers and the like. Nylon 66, nylon 6, nylon 66/6, and nylon 6T / 66 are more effective in terms of heat resistance, flame retardancy, and moldability.

The granular material (B) is obtained, for example, by subjecting the polyamide resin to polycondensation, cooling and cutting into a strand and granulating the polyamide resin, or melting and kneading with an extruder or the like to form a strand and cooling and cutting. And granulated. Here, the granular material indicates a general shape used for injection molding or extrusion molding, and does not limit the shape. In other words, the granular material may be a columnar material having a diameter of about 3 mm and a length of about 3 mm, or a powder having an average particle diameter of 300 μm. The polyamide resin granules (B) may contain a usual lubricant and a moldability improver in the polyamide resin.

The polyamide resin (a) used for the polyamide resin composition granules (A) and the polyamide resin granules (B)
There is no problem even if they are of the same or different types. In particular, when the melting point of the polyamide resin (a) is Tma and the melting point of the granular polyamide resin (B) is Tmb, Tm
It is more preferable that a ≦ Tmb is satisfied, and the effect of improving the dispersibility of the meamine cyanurate in the molded product in the polyamide resin is further enhanced. The flame-retardant polyamide resin molding material of the present invention is a mixture of the flame-retardant polyamide resin composition granules (A) and the polyamide resin granules (B).

The mixing ratio of the flame-retardant polyamide resin composition granules (A) and the polyamide resin granules (B) in the molding material is not particularly limited, and the finally obtained flame-retardant polyamide resin molding material is obtained. Is blended so as to contain 1 to 20% by weight of melamine cyanurate and 0.01 to 2% by weight of a surfactant in a molded article obtained by molding the above. Usually, the content of the flame-retardant polyamide resin composition granules (A) in the molding material is preferably 2 to 50% by weight, particularly preferably 3 to 40% by weight. When the flame-retardant polyamide resin composition granules (A) are out of this range, poor dispersion of melamine cyanurate is liable to occur and mechanical properties are likely to deteriorate.

In preparing the flame-retardant polyamide resin molding material (C) of the present invention, the method of mixing the flame-retardant polyamide resin composition granules (A) and the polyamide resin granules (B) is not particularly limited. Are mixed and blended in a blender, a mixer, a Newmar or the like. In producing a molded article using the molding material of the present invention, the molding method is not particularly limited, but generally various molding machines,
In particular, it can be produced by an injection molding machine, an extrusion molding machine, a press molding machine, or the like. Incidentally, the molding material of the present invention, if desired, various additives such as a heat stabilizer, an ultraviolet absorber, an antioxidant, a plasticizer, an antistatic agent, a weather resistance improver, a lubricant, a release agent, Other additives such as fillers, dyes and pigments,
Other resin polymers can be added as long as the object of the present invention is not impaired.

[0019]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to specific examples, but the present invention is not limited to these examples. In addition, the measurement of various characteristics in the examples was performed as follows. Tensile elongation at break Measured according to ASTM-D638 using an injection molded test piece. Tensile strength Using an injection molded test piece, the tensile strength was measured according to ASTM-D638. Flammability was measured by a method specified in UL-94 using a 1/32 inch injection molded test piece.

Evaluation of Melamine Cyanurate Dispersibility A rectangular molded product is injected using a mold having a length of 5 inches × a width of 0.5 inches × a thickness of 0.03 inches provided with gates at both ends in the length direction. Molded. The molded product has a portion where the molten resin flowing in from both ends merges at the center, and irregularities generated due to the melamine cyanurate dispersion state on the surface are visually observed and evaluated. The evaluation ranks of the dispersibility were three ranks: markedly noticeable (xx), noticeable (x), and hardly noticeable (o). (Xx) → (×) →
The better the (○), the better the dispersibility. Silver on the surface of the molded article was visually observed for the occurrence of silver at the leading edge of the flow of the test piece when injection molded at 280 ° C.

(Example 1) Nylon 66/6 copolymer (manufactured by Asahi Kasei Corporation, Leona 9200: melting point: 245)
C) and melamine cyanurate powder (MCA-C0, manufactured by Mitsubishi Chemical Corporation) using a weight feeder that can separately supply the melamine cyanurate powder so that the melamine cyanurate content becomes 30% by weight (Toshiba Machine Co., Ltd.) Company-made / TEM
35) After feeding from the hopper, while melt-extruding and kneading, use a liquid feed pump to feed side-feed polyethylene glycol (PEG400, manufactured by Sanyo Chemical Industries Co., Ltd.) so that the content becomes 1.5% by weight. After melt-kneading, the mixture was extruded into a strand, cooled with water, and then cut into cylindrical pellets having a diameter of 3 mm and a length of 3 mm using a cutter to obtain a flame-retardant polyamide resin composition granule. 1 kg of the flame-retardant polyamide resin composition granules and 9 kg of nylon 66 (Leona 1100 manufactured by Asahi Kasei Corporation: melting point 260 ° C.)
g were mixed and blended, and a molded piece was molded using an injection molding machine (PS40E, manufactured by Nissei Plastics Industry Co., Ltd.).
The concentration of melamine cyanurate in the obtained molded piece was 3
% And the concentration of polyethylene glycol were 0.15%. The test pieces thus obtained were measured for flame retardancy and mechanical properties. Table 1 shows the results.

(Examples 2 to 3) Example 1 was repeated except that the surfactant in Example 1 was changed to polyethylene glycol monolaurate, and the amount of the surfactant was changed to the ratio shown in Table 1.
It carried out similarly to. The flame retardancy and mechanical properties of the obtained molded pieces were measured. Table 1 shows the results. Example 4 Example 4 was carried out in the same manner as in Example 1 except that the surfactant in Example 1 was changed to polyethylene glycol monooleate. The flame retardancy and mechanical properties of the obtained molded pieces were measured. Table 1 shows the results.

(Example 5) The procedure of Example 1 was repeated except that the surfactant in Example 1 was changed to polyethylene glycol sorbintan monolaurate. The flame retardancy and mechanical properties of the obtained molded pieces were measured. Table 1 shows the results. (Example 6) The same procedure as in Example 2 was carried out except that the granulated flame-retardant polyamide resin composition of Example 2 and nylon 66 were changed to the ratios shown in Table 1. The flame retardancy and mechanical properties of the obtained molded pieces were measured. Table 1 shows the results.

Example 7 Nylon 66/6 of Example 2
Example 2 except that the copolymer, the melamine cyanurate and the surfactant were changed to the ratios shown in Table 1, and the obtained flame-retardant polyamide resin composition granules and nylon 66 were changed to the ratios shown in Table 1. It carried out similarly. The flame retardancy and mechanical properties of the obtained molded pieces were measured. Table 1 shows the results. (Example 8) The same procedure as in Example 2 was carried out except that the types of the flame-retardant polyamide resin composition granules and the polyamide resin granules in Example 2 were changed. The flame retardancy and mechanical properties of the obtained molded pieces were measured. Table 1 shows the results.

(Comparative Example 1) The same operation as in Example 1 was carried out except that the surfactant of Example 1 was not added. The flame retardancy and mechanical properties of the obtained molded pieces were measured. Table 1 shows the results. (Comparative Example 2) Except that the surfactant of Example 1 was changed to the ratio shown in Table 1, and the obtained flame-retardant polyamide resin composition granules and nylon 66 were changed to the ratio shown in Table 1. It carried out similarly to Example 1. Flame retardancy of the obtained molded piece,
The mechanical properties were measured. Table 1 shows the results.

(Comparative Example 3) Nylon 66 (Leona 1100, manufactured by Asahi Chemical Industry Co., Ltd., melting point: 260 ° C.) and melamine cyanurate powder (MCA, manufactured by Mitsubishi Chemical Corporation)
After melt kneading while feeding from a hopper of a twin-screw extruder (manufactured by Toshiba Machine Co., Ltd., TEM35) using a weight feeder capable of separately supplying C0) and melamine cyanurate so that the content of melamine cyanurate becomes 30% by weight, The mixture was extruded into a strand, cooled with water, and then cut into cylindrical pellets having a diameter of 3 mm and a length of 3 mm with a cutter to obtain a flame-retardant polyamide resin composition granule. 1 kg of this flame-retardant polyamide resin composition granule and nylon 66 (Leona 110, manufactured by Asahi Kasei Corporation)
0: melting point 260 ° C.) to obtain a ratio as shown in Table 1, and then a twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.)
The mixture was melt-extruded and kneaded with a TEM 35), extruded in a strand form, cooled with water, and then cut by a cutter into cylindrical pellets having a diameter of 3 mmφ × 3 mm to obtain a flame retardant polyamide resin composition.
The obtained composition was molded in the same manner as in Example 1, and the flame retardancy and mechanical properties of the molded piece were measured. Table 1 shows the results.

Comparative Example 4 The flame-retardant polyamide resin composition granules produced in Example 1 and the polyamide granules were mixed and blended in the proportions shown in Table 1, and then a twin-screw extruder (Toshiba Machine Co., Ltd.) Melt extrusion kneading with TEM35 manufactured by Co., Ltd., strand-shaped extrusion, water-cooling, and cutter 3m in diameter
It was cut into cylindrical pellets of mφ × 3 mm length to obtain a flame-retardant polyamide resin composition. The obtained composition was molded in the same manner as in Example 1, and the flame retardancy and mechanical properties of the molded piece were measured. Table 1 shows the results.

[0028]

[Table 1]

The surfactants used in the examples and comparative examples are shown below. * 1 Macrogol 400 manufactured by Sanyo Kasei Co., Ltd. * 2 Emanone 1112 manufactured by Kao Corporation * 3 Emanon 4110 manufactured by Kao Corporation * 4 Value7220 manufactured by Kanebo Co., Ltd.

[0030]

EFFECTS OF THE INVENTION The molding material of the present invention is excellent in the appearance of molded articles, has good dispersibility of melamine cyanurate, and is excellent in flame retardancy and mechanical properties, particularly in tensile elongation at break. It can be used for electrical and electronic parts that require properties and mechanical properties.

Claims (2)

[Claims] 1. A method comprising melt-kneading (A) a polyamide resin (a), melamine cyanurate (b) and at least one surfactant (c) selected from polyalkylene polyhydric alcohols or fatty acid esters thereof. (C) A flame-retardant polyamide resin molding material obtained by mixing a flame-retardant polyamide resin composition particle and (B) a polyamide resin particle, which is obtained from the flame-retardant polyamide resin molding material. The melamine cyanurate (b) content in the molded article is 1 to 20% by weight and the surfactant (c) content is 0.01
A flame-retardant polyamide resin molding material, characterized in that the content is from 2 to 2% by weight. 2. The melting point of the polyamide resin (a) used for the (A) flame-retardant polyamide resin composition granules is Tma,
(B) The flame-retardant polyamide resin molding material according to claim 1, wherein Tma ≦ Tmb is satisfied when the melting point of the polyamide resin particles is Tmb.