JP2000026721A - Flame-retardant polyamide rein composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame-retardant polyamide resin composition useful in a field of e.g. automobile industrial parts as e.g. a coating material for wire harnesses and capable of exhibiting an excellent hinge characteristic and flame- retardant property by adding a specific amount of a melamine cyanurate-based flame-retardant to a specific polyamide resin. SOLUTION: This composition is obtained by blending (A) 100 pts.wt. of a polyamide resin (e.g. containing 3 to 50 wt.% of the following resin A2) comprising (A1) an aliphatic polyamide (e.g. polyamide 66, polyamide 66-6 or polyamide 6) and (A2) a semiaromatic polyamide (e.g. polyamide 6T, polyamide MXD6 and polyamide 6I) with (B) 0.4 to 20 pts.wt. of a melamine cyanurate-based flame-retardant (e.g. melamine cyanurate or any derivatives obtained by substituting some OHs and aminos thereof with other substituents).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a flame-retardant polyamide resin composition having excellent hinge characteristics.

[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, and for example, molded products with hinges are inferior in hinge performance and cannot be applied, so that there is an unavoidable limitation in applications. 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 hinge characteristics.

[0004]

Means for Solving the Problems The present inventors have found that the above objects can be achieved by using a specific polyamide resin composition, and have completed the present invention based on this finding. That is, the present invention relates to a polyamide resin 10 comprising an aliphatic polyamide and a semi-aromatic polyamide.
0 parts by weight, and a melamine cyanurate flame retardant of 0.4 to 2
The present invention provides a flame-retardant polyamide resin composition comprising 0 parts by weight.

[0005]

DETAILED DESCRIPTION OF THE INVENTION In general, a polyamide is an acid amide bond
A chain polymer compound having (-CONH-) as a repeating unit, which is obtained by a polymerization method such as (1) ring-opening polymerization of lactam, (2) polycondensation of aminocarboxylic acid, and (3) diamine with diamine. They can be classified as those based on polycondensation of basic acids. These can be further classified into aliphatic polyamide, semi-aromatic polyamide, and aromatic polyamide according to the structure of the main chain. The aliphatic polyamide in the present invention is specifically polyamide 6, polyamide 11, polyamide 1
2, polyamide 66, polyamide 610, polyamide 6
12, polyamide 46, polyamide 66-6, polyamide 6-610, etc. Among them, polyamide 66, polyamide 66-6 and polyamide 6 are particularly preferred. The polyamide 66 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 semi-aromatic polyamide used in the present invention is a polyamide in which one of the dicarboxylic acids and diamines used is an aliphatic one and the other is an aromatic one. Examples of the aromatic dicarboxylic acid include terephthalic acid (T) and isophthalic acid (I), and examples of the aromatic diamine include meta-xylylenediamine (MXD). Specific examples of the semi-aromatic polyamide include polyamide 6T, polyamide MXD6, polyamide 6I, and polyamide 6I / 6T. In addition, polyamide 6T is obtained by hexamethylene diamine and terephthalic acid (T), polyamide MXD6 is obtained by polycondensation of metaxylylenediamine (MXD) and adipic acid, and polyamide 6I is obtained by polycondensation of hexamethylene diamine and isophthalic acid (I). Polyamide 6I / 6T is composed of hexamethylenediamine, isophthalic acid (I) and terephthalic acid (T)
Is a polyamide obtained by polycondensation. The above polyamide preferably has a relative viscosity (measured by a sulfuric acid method in accordance with JIS K6810) of 2.5 or more. In addition, these polyamides are not particularly limited by the type of terminal group or the ratio thereof.

The polyamide resin in the present invention comprises the above aliphatic polyamide and semi-aromatic polyamide. The compounding ratio of the semi-aromatic polyamide in the polyamide resin is generally 3 to 50% by weight, and 5 to 40% by weight.
Is preferable, and 10 to 30% by weight is particularly preferable.

The melamine cyanurate flame retardant of the present invention includes 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, and 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 blending ratio of the melamine cyanurate-based flame retardant is determined according to the polyamide resin 1 according to the present invention.
The amount is 0.4 to 20 parts by weight, preferably 0.6 to 10 parts by weight, particularly preferably 1 to 5 parts by weight with respect to 00 parts by weight. If the blending ratio of the melamine cyanurate-based flame retardant is less than 0.4 part 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 flame-retardant polyamide resin composition of the present invention is obtained by mixing the above polyamide resin and a melamine cyanurate-based 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.

Further, in producing the flame-retardant polyamide resin composition of the present invention, within a range not impairing its performance,
A stabilizer against oxygen, heat, light, and ultraviolet rays, a lubricant, an antistatic agent, a reinforcing agent, a coloring agent (such as a pigment), and other additives may be added.

[0011]

The present invention will be described in more detail with reference to the following examples. A polyamide 66 having a relative viscosity of 2.6 and a polyamide 6 having a relative viscosity of 2.6 as an aliphatic polyamide, and a polyamide 6I / 6T having a relative viscosity of 2.7 as a semi-aromatic polyamide (6I / 6T ratio) : 7/3)
Was 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
Was measured under the following conditions, and evaluated according to the following criteria.・ ・ ・: 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 a temperature of 23 ° C. and a humidity of 50% RH
No. dumbbells were measured according to ASTM D638. (3) Hinge characteristics A 2 mm-thick strip-shaped test piece having a hinge portion (thickness: 0.25 mm, length: 2 mm) at the center is left for 1 hour in an atmosphere of -10 ° C, and once at 180 ° by hand. It was bent and evaluated according to the following criteria. ○ ・ ・ ・ Hinges are not broken △ ・ ・ ・ Hinges are broken × ・ ・ ・ Hinges are broken and cut

Examples 1-3 Comparative Examples 1-2 Each polyamide and melamine cyanurate were mixed in advance with a tumbler in the types and amounts shown in Table 1, and then mixed.
30mm co-rotating twin screw extruder (PCM30 manufactured by Ikegai Iron Works)
And melt kneaded to produce a composition. The obtained composition was molded using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd.),
Various test pieces were prepared. The tensile elongation at break, hinge characteristics 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 hinge characteristics and has good flame retardancy, so it is particularly suitable for molded products having a hinge portion, and is used in automobile industrial parts such as cable protectors and covering materials for wire harnesses.
It is useful in a wide range of fields such as OA equipment parts and home appliances.

Continued on the front page (72) Inventor Osamu Hamazoe 3-2 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Showa Denko KK Kawasaki Laboratory (72) Inventor Hiroshi Kirikoshi Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa-ken No. 3-2 Showa Denko KK Kawasaki Laboratory F-term (reference) 4J002 CL011 CL031 CL051 CL061 EU186 EU196 FD136 GN00 GQ00

Claims (3)

[Claims] 1. A flame-retardant polyamide resin composition comprising 100 parts by weight of a polyamide resin comprising an aliphatic polyamide and a semi-aromatic polyamide, and 0.4 to 20 parts by weight of a melamine cyanurate-based flame retardant. 2. The flame-retardant polyamide resin composition according to claim 1, wherein the proportion of the semi-aromatic polyamide in the polyamide resin is 3 to 50% by weight. 3. The flame-retardant polyamide resin composition according to claim 1, wherein the aliphatic polyamide is at least one of polyamide 66, polyamide 66-6 and polyamide 6.