JP2003226798A - Wear-resistant heat-resistant flame-retardant resin composition and electrical wire covered therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an uncrosslinked wear-resistant flame-retardant resin composition greatly improved in wear resistance without deteriorating flexibility. <P>SOLUTION: The resin composition is obtained by blending (a) 50-95 mass pts. of a polybutylene terephthalate and (b) 5-50 mass pts. of a styrenic elastormer [the total of component (a) and component (b) being 100 mass pts.] with (c) 3-50 mass pts. of a nitrogenous compound. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

The present invention relates to a wear resistant heat resistant flame retardant resin composition and an electric wire coated with the same. Such a covered electric wire is useful as an electric wire for an automobile, for example.

[0002]

2. Description of the Related Art Polyvinyl chloride has been mainly used as a coating material for electric wires for automobiles. that is,
This is because polyvinyl chloride was excellent in mechanical strength, wire extrusion processability, flexibility and colorability. However, in consideration of recent global environment countermeasures, halogen-free resin materials have been used in place of polyvinyl chloride in the manufacture of automobile parts, including coating of electric wires for automobiles.

As a wear-resistant resin composition having the advantage that it does not generate a toxic gas such as a halogen gas during combustion, a halogen-free resin composition in which a metal hydroxide is mixed as a flame retardant with a polyolefin base polymer is known. (JP-A-7-176219 and JP-A-7-176219)
78518, etc.). However, in order to make the disclosed resin composition flame-retardant to the extent that it has self-extinguishing properties, it is necessary to add a large amount of metal hydroxide. There is a problem that the mechanical strength such as abrasion resistance and tensile strength is extremely reduced.
In order to avoid a decrease in mechanical strength, it is possible to increase the amount of polypropylene or high-density polyethylene, which has a relatively high hardness, but doing so impairs the flexibility of the covered electric wire,
The workability also deteriorates.

Various other flame-retardant resin compositions have been proposed in the field of electric wire coating. A composition obtained by blending a polyester resin such as polybutylene terephthalate with a nitrogen-containing compound as a flame retardant is disclosed in JP-A-7-12649.
No. 8, JP-A-9-53007, and JP-A-10-
It is disclosed in Japanese Patent Laid-Open No. 3168433, Japanese Patent Laid-Open No. 2000-154322, and the like. However, the flexibility of these polyester resin compositions is not yet satisfactory.

Compositions prepared by blending a polyolefin such as polyethylene with a nitrogen-containing compound as a flame retardant are disclosed in JP-A-6-157820, JP-A-2-75642, JP-A-9-316250, and JP-A-2000. −
It is disclosed in JP-A-178386, JP-A-2000-212404 and JP-A-2000-294036. However, the elongation and abrasion resistance of these polyolefin resin compositions need to be further improved.

[0006]

DISCLOSURE OF THE INVENTION The present invention is intended to provide an abrasion resistant flame retardant resin composition in which abrasion resistance is remarkably improved without impairing flexibility.

[0007]

In order to solve the above-mentioned problems, the present invention provides (a) polybutylene terephthalate 50.
To 95 parts by mass, (b) styrene elastomer 5 to 50
There is provided a resin composition comprising parts by mass (however, the total of the polymers (a) and (b) is 100 parts by mass), and (c) a nitrogen-containing compound in an amount of 3 to 50 parts by mass.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The components of the composition of the present invention are selected to combine to provide the desired properties. Hereinafter, those components will be described. The polybutylene terephthalate (a) may be a conventionally known one, and its molecular structure, density and other properties are not particularly limited.
The amount of polybutylene terephthalate (a) is 50 in the total amount (100 parts by mass) of the polymers (a) and (b).
To 95 parts by mass, preferably 70 to 90 parts by mass. When the ratio of the polybutylene terephthalate (a) exceeds the above upper limit, the flexibility of the composition decreases, while when the ratio is less than the above lower limit, the elongation of the composition is not improved,
Wear resistance deteriorates.

The styrene elastomer (b) is a block copolymer of styrene and a diene (eg, butadiene, isoprene, etc.) (eg, styrene-butadiene block copolymer (SBS, SBR), styrene-isoprene block copolymer). It is a polymer (SIS, SIR) or a hydrogenated block copolymer (SEBS, etc.) obtained by saturating the double bond of such a block copolymer by hydrogenation. The copolymer may optionally be modified with an organic carboxylic acid anhydride, typically an unsaturated acid anhydride, preferably an acid anhydride such as maleic anhydride. The amount is preferably 0.1 to 10% by weight based on the (hydrogenated) block copolymer.

The amount of the styrene elastomer (b) contained in the total amount (100 parts by mass) of the polymers (a) and (b) in the composition is usually 5 to 50 parts by mass, preferably 1 part.
It is 0 to 30 parts by mass. Styrenic elastomer (b)
When the ratio exceeds the above upper limit, the elongation of the composition is not improved and the wear resistance is deteriorated. On the other hand, if the proportion of the styrene elastomer (b) is less than the above lower limit, the flexibility of the composition will be impaired.

As the nitrogen-containing compound (c), there are used nitrogen-containing compounds conventionally used as flame retardants (for example,
(Melamine cyanurate, melamine, cyanuric acid, isocyanuric acid, triazine derivative, isocyanurate derivative, etc.) can all be used, but melamine cyanurate is particularly preferable. Melamine cyanurate is used in the form of particles (powder), and even if untreated, it is a coupling agent, particularly a silane coupling agent (for example, an aminosilane coupling agent, a vinylsilane coupling agent, an epoxysilane coupling agent, a methacrylic coupling agent). It may be surface-treated with a surface-treating agent such as a roxysilane coupling agent) or a higher fatty acid (eg stearic acid, oleic acid). Typically, silane coupling agents include Si-O bonds that bond to the hydroxide. Among them, a melamine isocyanurate surface-treated with a coupling agent, preferably a silane coupling agent, and particularly an aminosilane coupling agent is particularly preferable. It is also possible to carry out so-called integral blending in which the melamine cyanurate particles are blended with the resin as they are without surface-treating with a coupling agent or the like in advance, and at the same time, the coupling agent or the like is blended.

The ratio of the nitrogen-containing compound (c) to the total amount (100 parts by mass) of the components (a) and (b) in the composition is usually 3 to 50 parts by mass, preferably 5 to 30 parts by mass. . If the amount of the nitrogen-containing compound (c) exceeds the above upper limit, the abrasion resistance of the composition will be impaired. On the other hand, if the amount of the nitrogen-containing compound (c) is less than the above lower limit, the flame retardancy of the composition will not be improved.

In the resin composition of the present invention, a compounding agent that is usually compounded with polybutylene terephthalate, such as a heat stabilizer (such as an antioxidant), a metal deactivator (such as a copper damage inhibitor), a lubricant (a fatty acid). , Fatty acid amide, metal soap, hydrocarbon (wax), ester, silicone lubricant, light stabilizer, nucleating agent, antistatic agent, colorant, flame retardant aid (zinc borate, silicone flame retardant aid) , Nitrogen-based flame retardant aids, etc.),
Add a coupling agent (silane coupling agent, titanate coupling agent, etc.), softening agent (process oil, etc.), cross-linking aid (polyfunctional monomer, etc.) in an amount that does not reduce the above properties. It may be crosslinked. The resin composition of the present invention can be prepared by mixing and kneading the above-mentioned components by a usual method. The method for coating an electric wire, particularly an electric wire for an automobile, with the resin composition of the present invention is the same as the conventional method.

[0014]

EXAMPLES The present invention will be described more specifically by showing examples and comparative examples. Examples 1 to 5 and Comparative Examples 1 to 5 The components shown in Tables 1 and 2 were mixed in the indicated amounts (parts by mass) and kneaded at 250 ° C with a twin-screw extruder. The composition obtained was extruded around a conductor (7 / SB) having a cross-sectional area of 0.5 mm ² with a coating thickness of 0.2 mm. For the extrusion molding, dies and nipples with diameters of 1.20 mm and 0.88 mm were used, respectively, and the extrusion temperature was between dies 250-26.
Extrusion molding was performed at 0 ° C. and a cylinder temperature of 230 to 250 ° C. at a linear velocity of 30 m / min.

The following characteristics of the coated electric wires obtained in Examples 1 to 5 and Comparative Examples 1 to 5 were evaluated. Tensile elongation and tensile strength: Tensile elongation and tensile strength are
The measurement was performed according to JASO (Japan Automobile Manufacturers Association) D 611. Flame retardancy and abrasion resistance: JASO
It was measured according to D 611. The abrasion resistance is the minimum value when the number of samples is 3, and 150 times or more pass. Flexibility: Flexibility was evaluated by touch when bending an electric wire. Workability: The results are shown in Tables 1 and 2.

[0016]

[Table 1]

[0017]

[Table 2]

Note: 1) Polybutylene terephthalate manufactured by Teijin Limited. 2) Hydrogenated styrene-butadiene block copolymer manufactured by Asahi Kasei Corporation. 3) Asahi Kasei Corporation maleic anhydride modified hydrogenated styrene-butadiene block copolymer. 4) Made by Nissan Sangyo Co., Ltd. 5) Kyowa Chemical Industry Co., Ltd. 6) Polycarbodiimide resin manufactured by Nisshinbo Co., Ltd.

As can be seen from the results of Comparative Example 1, if the flame retardant (melamine cyanurate or magnesium hydroxide) is not added, the flame retardancy of the composition is impaired and the abrasion resistance is not improved. As can be seen from the results of Comparative Example 2, if the amount of the flame retardant is too small, the flame retardancy of the composition does not improve. As can be seen from the results of Comparative Example 3, when the amount of polybutylene terephthalate is too small (the amount of styrene elastomer is too large), the elongation of the composition is not improved and the abrasion resistance is impaired. As can be seen from the results of Comparative Example 4, if the amount of polybutylene terephthalate is too large (the amount of styrene-based elastomer is too small), the flexibility of the composition will be impaired. As can be seen from the results of Comparative Example 5, when a flame retardant other than the nitrogen-containing compound is used, the elongation, abrasion resistance and flexibility of the composition are impaired.

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) (C08L 67/02 H01B 7/28 Z 53:02) (72) Inventor Masafumi Sato 1st Nishisuehirocho, Yokkaichi-shi, Mie Prefecture No. 14 Sumitomo Wiring Systems Co., Ltd. (72) Inventor Kaneko Arai No. 14 Nishi-Suehiro-cho, Yokkaichi-shi, Mie F-Term inside Sumitomo Wiring Systems Co., Ltd. (reference) 4J002 BP012 CF071 EU186 EU196 FB146 FD136 GQ01 5G305 AA02 AB25 AB40 BA13 CA12 CA47 CD20 5G313 FA09 FB04 FB08 FD01 FD09 FD12 5G315 CA03 CA04 CB02 CB06 CD01 CD08 CD17

Claims (6)

[Claims] 1. (a) Polybutylene terephthalate 50
To 95 parts by mass, (b) 5 to 50 parts by mass of the styrene elastomer (however, the total of the polymers (a) and (b) is 100 parts by mass), and (c) the nitrogen-containing compound 3 to 50 parts by mass. A resin composition comprising: 2. The resin composition according to claim 1, wherein the styrene elastomer (b) is a block copolymer containing a polystyrene block and a polybutadiene or polyisoprene block. 3. The resin composition according to claim 1, wherein the nitrogen-containing compound (c) is melamine cyanurate. 4. The resin composition according to claim 3, wherein the melamine cyanurate is a particulate melamine cyanurate surface-treated with a coupling agent. 5. The resin composition according to claim 4, wherein the coupling agent is a silane coupling agent. 6. An electric wire coated with the resin composition according to claim 1.