JP2002302602A - Flame-retardant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame-retardant resin composition which does not generate a harmful halogen gas on combustion, excels in flame retardance and flaw resistance, has good mechanical properties, and is suited in use for the insulator and the sheath of a power supply cord. SOLUTION: The flame-retardant resin composition is obtained by incorporating a polyolefin polymer and/or a thermoplastic elastomer into a thermoplastic polyurethane and adding a nonhalogen flame-retardant to the thermoplastic polyurethane of a base polymer which makes up 5-70 wt.% of the total amount. Further, it is preferred that 40-200 pts.wt. nonhalogen flame-retardant is added to 100 pts.wt. base polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-halogen flame-retardant resin composition suitable for insulators and sheaths of electric wires such as power cords, which has high flame retardancy and mechanical properties, and is particularly resistant to trauma. It is a thing that raised the character.

[0002]

2. Description of the Related Art Insulators or sheaths of power cords such as single-core cords, flat cords, and cabtire cords include:
Conventionally, a plasticized polyvinyl chloride composition and an ethylene-propylene rubber composition have been used. However, in the case of the plasticized polyvinyl chloride composition, harmful halogen gas is generated at the time of its combustion, and furthermore, the use of environmental hormones in the plasticizer causes environmental pollution. .

[0003] On the other hand, those made of an ethylene-propylene rubber composition have the drawback that the insulator and the sheath become hard, lack flexibility, and are inferior in handleability. There is also a disadvantage that it has almost no flame retardancy. In addition, there is a drawback that the production cost is increased because the crosslinking is required. For this reason, it has recently been proposed to use a halogen-free flame-retardant resin composition in which a large amount of a metal hydroxide such as magnesium hydroxide is blended with a polyolefin polymer such as polyethylene for the insulator or sheath of these power cords.

[0004] However, this non-halogen flame-retardant resin composition has a disadvantage that the resulting insulator or sheath is easily damaged and has poor trauma resistance. By the way, thermoplastic polyurethane is one of the resin materials having high trauma resistance. However, this thermoplastic polyurethane has low flame retardancy. In such a case, mechanical properties such as tensile strength and elongation decrease.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a power cord which does not generate harmful halogen gas during combustion, has excellent flame retardancy and trauma resistance, has excellent mechanical properties, To obtain a flame-retardant resin composition suitable for an insulator or a sheath.

[0006]

An object of the present invention is to provide a thermoplastic polyurethane obtained by blending a polyolefin polymer and / or a thermoplastic elastomer with a thermoplastic polyurethane. The problem can be solved by a flame-retardant resin composition containing a flame retardant. Further, it is preferable to add 40 to 200 parts by weight of a non-halogen flame retardant to 100 parts by weight of the base polymer.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The base polymer constituting the flame-retardant resin composition of the present invention is made of a thermoplastic polyurethane as an essential component, and a blend of a polyolefin polymer or a thermoplastic elastomer or a polyolefin polymer and a thermoplastic elastomer with the thermoplastic polyurethane. There are three types of combinations: a combination of polymers, a combination of a thermoplastic polyurethane and a thermoplastic elastomer, and a combination of a thermoplastic polyurethane, a polyolefin polymer, and a thermoplastic elastomer.

The thermoplastic polyurethane is a polyurethane having a linear molecular chain using a polymethylene polyphenyl polyisocyanate, tolidine diisocyanate, hexamethylene diisocyanate or the like as an isocyanate component and a diol such as a polyester diol or polyether diol as a polyol component. Thermoforming is possible, rich in elasticity, high molecular bonding cohesion energy, abrasion resistance,
Elastomer with excellent scratch resistance.

As the polyolefin polymer, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, and the like are used. Even those having a polar comonomer such as an ethylene-vinyl acetate copolymer and an ethylene-ethyl acrylate copolymer will have an appropriate polarity, and the affinity with the metal hydroxide of the non-halogen flame retardant is improved, which is preferable. . As the ethylene-vinyl acetate copolymer, one having a vinyl acetate content of 5 to 40 wt% is preferable, and as the ethylene-ethyl acrylate copolymer, one having an ethyl acrylate content of 5 to 35 wt% is preferable.

As the thermoplastic elastomer, various thermoplastic elastomers such as styrene-based thermoplastic elastomer, olefin-based thermoplastic elastomer, ester-based thermoplastic elastomer, urethane-based thermoplastic elastomer, and amide-based thermoplastic elastomer are used. Of these, styrene-based thermoplastic elastomers are particularly preferred.

This styrenic thermoplastic elastomer is
A triblock copolymer using at least one of polystyrene as a hard segment and polybutadiene, polyisoprene, polyethylene, polypropylene, and polybutylene as a soft segment is used. Specifically, a polystyrene-polybutadiene-polystyrene elastomer (SBS), One or more of polystyrene-polyisoprene-polystyrene elastomer (SIS), polystyrene-poly (ethylene-butylene) -polystyrene elastomer (SEBS), and polystyrene-poly (ethylene-propylene) -polystyrene elastomer (SEPS) are used. However, polystyrene-poly (ethylene-butylene) -polystyrene elastomer (SEBS) is preferred.

In the base polymer composed of two or three kinds of polymers, the proportion of the thermoplastic polyurethane is 5 to 70% by weight of the total amount of the base polymer. If it is not obtained and exceeds 70% by weight, the flame retardancy of the resin composition is greatly reduced, and the amount of the non-halogen flame retardant described later must be increased.

Therefore, in the base polymer composed of two components, the polyolefin polymer or the thermoplastic elastomer accounts for the remaining 30 to 95% by weight.
Further, in the case of a base polymer composed of three components, the total amount of the polyolefin polymer and the thermoplastic elastomer is 3
0 to 95% by weight, of which the polyolefin polymer is 0 to 90% by weight of the total amount of the base polymer.
It is desirable that the thermoplastic elastomer also accounts for 30 to 95% by weight.

Non-halogen flame retardants include metal hydroxides such as magnesium hydroxide, aluminum hydroxide and calcium hydroxide, silicone compounds such as silicone powder and silicone gum, phosphorus compounds such as ammonium polyphosphate, metal salts of molybdate, Examples include molybdenum compounds such as molybdenum oxide, boron compounds such as zinc borate, and tin compounds such as tin oxide.

The above-mentioned metal hydroxide is blended in a relatively large amount as a main flame retardant, and a relatively small amount of other compounds is blended as a flame retardant aid. Further, it is preferable to use a metal hydroxide which has been subjected to a surface treatment with a titanate coupling agent, a silane coupling agent, a higher fatty acid or the like, since the affinity with the base polymer is increased.

The amount of the non-halogen flame retardant is determined depending on the flame retardancy required for the flame retardant resin composition.
00 parts by weight, preferably 60 to 150 parts by weight.
Less than 40 parts by weight hardly provides flame retardancy,
If the amount is more than 10 parts by weight, mechanical properties such as tensile strength and elongation of the obtained resin composition are reduced. 80 to 80% of compounding amount of flame retardant
90 wt% is occupied by metal hydroxide, and 10 to 20
It is preferred that the flame retardant aid occupies wt%.

[0017] If necessary, an antioxidant, an ultraviolet absorber, carbon black, a coloring agent, and the like can be appropriately added to the flame retardant resin composition.

The electric wire of the present invention has a covering material such as an insulator or a sheath made of the above-described flame-retardant resin composition. Specifically, the flame-retardant resin composition is kneaded, on a conductor, on an insulator, a wire obtained by extrusion coating on a presser winding, a cord, a cable, more specifically, a single-core cord, An insulator of a cord such as a flat cord, a sheath of a cabtire cord and the like are made of the flame-retardant resin composition.

In such a flame-retardant resin composition,
Since thermoplastic polyurethane is blended as an essential component in the base polymer, it exhibits good trauma resistance and is hardly damaged. In addition, since a polyolefin polymer and / or a thermoplastic elastomer is blended, the affinity with a non-halogen flame retardant, particularly a metal hydroxide, is increased, so that a relatively large amount of the metal hydroxide can be blended and a high flame retardancy can be obtained. And a decrease in mechanical properties such as tensile strength and elongation can be suppressed.

Further, since a non-halogen flame retardant is used, no harmful halogen-containing gas is generated when the flame-retardant resin composition is burned. In addition, this flame-retardant resin composition does not contain a plasticizer such as a phthalate ester, so that a plasticizer, which is considered to be an environmental hormone, does not ooze out and there is no concern about environmental pollution.

For this reason, in the flame retardant resin composition of the present invention, by selecting the compounding amount of the non-halogen flame retardant, the flame retardancy that passes the 60-degree inclined combustion test specified in JIS C 3005 can be obtained. While exhibiting mechanical properties of tensile strength of 10 MPa or more and elongation of 350% or more.

The following is a specific example. A resin composition having the composition shown in Tables 1 and 2 was prepared, kneaded with an extruder, formed into a sheet having a thickness of 2 mm, and used as a test piece. Further, the same resin composition was extrusion-coated on a conductor having a diameter of 1.5 mm by a similar extruder to provide an insulator having a thickness of 2 mm to produce a single-core cord.

Regarding the single core cord, JIS C 30
The flame retardancy was evaluated by performing a 60-degree inclined combustion test specified in No. 05. For the test pieces, the hardness (Shore D, 5
Sec), tensile strength and elongation were measured. Further, the scratch resistance was evaluated using a NEMA abrasion tester. Tensile strength is 1
0 MPa or more and elongation of 350% or more pass. The results are shown in Tables 1 and 2.

[0024]

[Table 1]

[0025]

[Table 2]

In Tables 1 and 2, “EVA” is
Ethylene-vinyl acetate copolymer (vinyl acetate content 20w
t%), “EEA” is an ethylene-ethyl acrylate copolymer (ethyl acrylate content 15 wt%),
“TPE” indicates a polystyrene-poly (ethylene-butylene) -polystyrene block copolymer (SEBS) as a thermoplastic elastomer, and “TPU” indicates a thermoplastic polyurethane.

[0027]

As described above, in the flame-retardant resin composition of the present invention, since the thermoplastic polyurethane is blended as an essential component of the base polymer, it exhibits good trauma resistance, It becomes hard to be damaged. Furthermore, since a polyolefin polymer and / or a thermoplastic elastomer is blended, it has a good affinity with a non-halogen flame retardant, a large amount of a non-halogen flame retardant can be added, high flame retardancy is obtained, and a decrease in mechanical properties is obtained. Can be suppressed.

Since a non-halogen flame retardant is used, no harmful halogen-containing gas is generated during combustion. In addition, since no plasticizer is contained, the plasticizer, which is regarded as an environmental hormone, does not ooze out, and there is no concern about environmental pollution.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01B 3/00 H01B 3/00 A 3/30 3/30 B N 7/295 7/34 B F term ( Reference) 4J002 BB03X BB06X BB07X BB12X BB15X BP00Y BP01Y BP03Y CK03W CK04W DE076 DE086 DE096 DE146 DE186 DH056 DK006 FB086 FD136 GQ01 5G303 AA06 AB20 BA12 CA09 CA11 CD03 5G305 AA02 AB15 AB03 AB03 CD17

Claims (3)

[Claims] 1. A thermoplastic polyurethane comprising a polyolefin polymer and / or a thermoplastic elastomer blended therein.
A flame-retardant resin composition comprising a base polymer occupying a non-halogen flame retardant. 2. The flame-retardant resin composition according to claim 1, wherein 40 to 200 parts by weight of a halogen-free flame retardant is added to 100 parts by weight of the base polymer. 3. An electric wire using the flame-retardant resin composition according to claim 1 as a covering material.