JPH11349809A - Flame-retarded polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition excellent in tensile elongation at break by compounding respective specific amounts of a polyamide resin mixture composed of a specific weight ratio of polyamide 66, polyamide 6 and one or more of polyamides 66-6, and a melamine cyanurate flame retardant. SOLUTION: A polyamide resin composition contains: 100 pts.wt. of polyamide mixture composed of 20-85 wt.% polyamide 66 and 80-15 wt.% polyamide 6 or one or more of polyamides 66-6; and 0.4-20 pts.wt. of melamine cyanurate flame retardant having an average particle size of not more than 100 μm, and the tensile elongation at break of the resin composition is not less than 100%. Further, if necessary, the resin composition is combined with a stabilizer to oxygen, light, ultraviolet rays and the like, a lubricant, an antielectrostatic, a reinforcing agent and the like. The melamine cyanurate flame retardants include melamine cyanurate, mono(β-cyanoethyl)isocyanurate, bis(β-cyanoethyl) isocyanurate, tris(β-cyanoethyl)isocyanurate, and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flame-retardant polyamide resin composition having a high tensile elongation at break.

[0002]

2. Description of the Related Art Polyamide resins are widely used as engineering plastics because of their excellent thermal, mechanical, electrical and chemical properties. In addition, with the recent diversification of uses of plastic materials, flame retardancy has been required for polyamide resins. Conventionally, to impart flame retardancy to a polyamide resin, use of melamine cyanurate (Japanese Patent Application Laid-Open No. 53-031)
759) or a combination of melamine cyanurate and magnesium hydroxide (JP-A-7-003152, JP-A-7-3103).
No. 10011) has been proposed.

[0003]

However, all of the molded products obtained by the above method have a low tensile elongation at break. For example, a molded product with a hinge is inferior in hinge performance and cannot be applied, so that the use of the molded product is inevitably restricted. was there. The present invention has been made in view of such circumstances, and has as its object to provide a flame-retardant polyamide resin composition having excellent tensile elongation at break.

[0004]

Means for Solving the Problems The present inventors have found that the above object can be achieved by using a specific polyamide resin mixture, and have completed the present invention based on this finding. That is, the present invention relates to polyamide 66
20 to 85% by weight and at least one polyamide of polyamide 6 or polyamide 66-6
100 parts by weight of a polyamide resin mixture consisting of
An object of the present invention is to provide a flame-retardant polyamide resin composition comprising from 0.4 to 20 parts by weight of a melamine cyanurate-based flame retardant.

[0005]

DETAILED DESCRIPTION OF THE INVENTION Polyamide 66 in the present invention
Is a polyamide resin obtained by polycondensing hexamethylenediamine and adipic acid. Polyamide 6 is obtained by ring-opening polymerization of ε-caprolactam, and polyamide 66-6 is a polyamide resin obtained by copolymerizing hexamethylenediamine, adipic acid and ε-caprolactam. The polyamide resin,
The relative viscosity (measured by a sulfuric acid method according to JIS K6810) is usually preferably 2.5 or more. In addition, these polyamide resins are not particularly limited by the type or the ratio of the terminal groups.

[0006] The polyamide resin mixture in the present invention comprises:
20 to 85% by weight of the polyamide 66 and 80 to 15% by weight of a polyamide made of at least one of polyamide 6 and polyamide 66-6.
The composition ratio of polyamide 66 in the resin mixture is preferably 30 to 80% by weight, more preferably 5 to 80% by weight.
0 to 75% by weight. When the composition ratio of polyamide 66 is 2
If it is less than 0% by weight, the flame retardancy is insufficient, while if it exceeds 85% by weight, the tensile elongation at break decreases, which is not preferable.

Examples of the melamine cyanurate flame retardant include melamine cyanurate and melamine cyanurate derivatives in which some of the hydroxyl groups and amino groups of melamine cyanurate are substituted with other substituents. Specific examples include melamine cyanurate, mono (β-cyanoethyl) isocyanurate, bis (β-cyanoethyl) isocyanurate, and tris (β-cyanoethyl) isocyanurate. Melamine cyanurate is
An equimolar reaction product of melamine and cyanuric acid can be obtained, for example, by mixing an aqueous solution of cyanuric acid and an aqueous solution of melamic acid, and filtering the resulting precipitate.
Other derivatives can be obtained in a similar manner. The shape is preferably a fine powder having an average particle diameter of 100 μm or less. Further, the mixing ratio of the melamine cyanurate-based flame retardant is 0.1 part by weight with respect to 100 parts by weight of the polyamide resin mixture.
It is 4 to 20 parts by weight, preferably 0.6 to 10 parts by weight, particularly preferably 1 to 5 parts by weight. If the blending ratio of the melamine cyanurate-based flame retardant is less than 0.4 parts by weight, the effect of flame retardancy is not sufficient, and if it exceeds 20 parts by weight, no further effect can be expected.

The polyamide resin composition of the present invention is obtained by mixing the above polyamide resin mixture and a melamine cyanurate flame retardant. The order of mixing is not particularly limited, and the melamine cyanurate-based flame retardant may be mixed after the polyamide resin is mixed in advance, or each component may be mixed simultaneously. The mixing method is not particularly limited, and a method generally used in the field of synthetic resins may be employed. Specifically, a method of dry-blending using a mixer such as a Henschel mixer, a tumbler and a ribbon blender, and then kneading in a molten state using a kneader such as a screw type extruder, and the like can be given.

The tensile elongation at break of the obtained polyamide resin composition is preferably 100% or more from the viewpoint of hinge properties.

In producing the polyamide resin composition of the present invention, stabilizers for oxygen, heat, light and ultraviolet rays, lubricants, antistatic agents, reinforcing agents, coloring agents (such as pigments) are used as long as the performance is not impaired. ) And other additives.

[0011]

The present invention will be described in more detail with reference to the following examples. As the polyamide resin, polyamide 66 having a relative viscosity of 2.6, polyamide 66-6 having a relative viscosity of 2.6, and polyamide 6 having a relative viscosity of 2.6 were used.

The test method is described below. (1) Flame retardancy test Using a test piece having a length of 100 mm, a width of 6 mm and a thickness of 1 mm, an oxygen concentration of 24% by volume in accordance with JIS K7201
The measurement was performed under the following conditions and evaluated as follows.・ ・ ・: Fire extinguished within 4 seconds of test specimen ×: Test specimen continued to burn for more than 4 seconds (2) Tensile elongation at break ASTM1 with equilibrium water absorption at 23 ° C and 50% RH
No. dumbbells were measured according to ASTM D638.

Examples 1-4 Comparative Examples 1-2 After the polyamide resin and melamine cyanurate were mixed in advance with a tumbler in the types and amounts shown in Table 1, a 30 mm co-directional twin-screw extruder (Ikegai Iron Works Co., Ltd.) PCM3
0) and melt-kneaded to produce a composition. The obtained composition was molded using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd.) to prepare various test pieces. The tensile elongation at break and flame retardancy of each test piece were measured. Table 1 shows the results.

[0014]

[Table 1]

[0015]

The flame-retardant polyamide resin composition of the present invention comprises:
It is excellent in tensile elongation at break and has good flame retardancy, so it is particularly suitable for molded products having hinge parts, and is widely used in automobile industrial parts such as cable protectors and coating materials for wire harnesses, OA equipment parts, and home electric appliances. Useful in the field.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kirikoshi 3-2 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Showa Denko Co., Ltd.

Claims (2)

[Claims] 1. 100 parts by weight of a polyamide resin mixture comprising 20 to 85% by weight of polyamide 66 and 80 to 15% by weight of polyamide 6 or at least one kind of polyamide 66-6, and 0.4 of a melamine cyanurate flame retardant A flame-retardant polyamide resin composition comprising up to 20 parts by weight. 2. The flame-retardant polyamide resin composition according to claim 1, wherein the tensile elongation at break is 100% or more.