JPH06220264A - Flame-retardant resin composition and frame-retardant insulated wire - Google Patents

Abstract

PURPOSE:To obtain a new hear-resistant flame-retardant resin compsn. and a flame-retardant insulated wire. CONSTITUTION:A compsn. comprising 100 pts.wt. ethylene copolymer, 5-60 pts.wt. flame retardant consisting of ethylenebis(tetrabromophthalimide) and/or perchlorocyclopentadecane, and 5-60 pts.wt. antimony trioxide is compounded with hydrotalcite in an amt. of 10-50wt.% of the flame retardant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant resin composition which is flame-retardant and particularly excellent in heat resistance, and a flame-retardant insulated wire using the same.

[0002]

2. Description of the Related Art Halogenated polyolefins such as chlorinated polyethylene and chlorinated paraffin, and halogen-based flame retardants such as bromine-based and chlorine-based flame retardants have been used for flame-retarding polyolefins that have been conventionally used as insulating materials for electric wires. It is carried out using a flame retardant or a non-halogen flame retardant using a hydroxide such as magnesium hydroxide or aluminum hydroxide.

The halogenated polyolefin itself can be used as a base polymer, but a system in which it is blended with other polyolefin is generally used, and an addition type flame retardant is added to the base polymer to make it flame-retardant. The characteristic feature of these halogen-based flame retardants is that they can impart high flame retardancy.

On the other hand, the non-halogen flame retardant produces water during combustion, which suppresses combustion, and therefore has the advantage that almost no toxic gas is generated.

[0005]

However, halogen-based flame retardants have the drawback of producing corrosive gases such as hydrogen halides during combustion, and non-halogen flame-retardants have sufficient flame retardancy. In addition, there is a drawback that a large amount of addition is required, which results in deterioration of mechanical properties. Further, these flame retardants also have a drawback of lowering heat resistance, and in order to have good heat resistance, a large amount of antioxidant must be added, which causes bloom and bleed.

Therefore, the present invention was devised to effectively solve this problem, and its purpose is to provide a novel flame-retardant resin composition having excellent heat resistance and flame retardancy, and A flame-retardant insulated wire is provided.

[0007]

In order to solve the above-mentioned problems, the first invention is based on 100 parts by weight of an ethylene-based copolymer, at least one of ethylene bis-tetrabromophthalimide and perchlorocyclopentadecane flame retardant 5 To 60 parts by weight and 5 to 60 parts by weight of antimony trioxide in a composition,
A flame-retardant resin composition containing 50% by weight of hydrotalcite, and a second invention is a flame-retardant insulated wire formed by coating the conductor with the flame-retardant resin composition. .
The third invention is based on 100 parts by weight of an ethylene-based copolymer, 5 to 60 parts by weight of at least one flame retardant of ethylene bis-tetrabromophthalimide or perchlorocyclopentadecane, and 5 to 6 parts of antimony trioxide.
Flame-retardant resin composition obtained by adding magnesium oxide and zinc oxide in a ratio of 1: 3 to 3: 1 in an amount of 0 part by weight to the above flame retardant in an amount of 10 to 50% by weight. The fourth invention is a flame-retardant insulated electric wire obtained by coating a conductor with the flame-retardant resin composition of the third invention.

The ethylene copolymer used in the present invention means an ethylene-vinyl acetate copolymer, ethylene methacrylate, ethylene ethyl acrylate, linear low density polyethylene, ultra low density polyethylene, ethylene propylene rubber, ethylene propylene diene ternary copolymer. Examples include polymers and ethylene butyl acrylate.

Further, ethylene bistetrabromophthalimide, perchlorocyclopentadecane, and antimony trioxide are limited to 5 to 60 parts by weight. When the amount is less than 5 parts by weight, the flame retardant effect is small, and when the amount exceeds 60 parts by weight. It has no further effect.

In the first and second inventions, the content of hydrotalcite is limited to 10 to 50% by weight of the flame retardant.
This is because if it is less than 50% by weight, the halogen stabilizing effect is small, and if it exceeds 50% by weight, no further effect is exerted, and conversely the mechanical properties are deteriorated or deterioration is accelerated. Considering heat resistance and bloom, these flame retardants are preferably 20 to 50 parts by weight with respect to 100 parts by weight of the base polymer.

In the third and fourth inventions, the ratio of zinc oxide and magnesium oxide is defined to be 1: 3 to 3: 1 because the synergistic effect of both is impaired if it exceeds this range.
The amount of these additives added is limited to 10 to 50% by weight of the flame retardant because less than 10% by weight has less halogen stabilizing effect, and more than 50% by weight has no further effect.
On the contrary, the mechanical characteristics are deteriorated and the deterioration is promoted. Considering heat resistance and bloom, these flame retardants are preferably 20 to 50 parts by weight with respect to 100 parts by weight of the base polymer.

Crosslinking is carried out by a known method using sulfur, organic peroxide, electron beam or the like. In addition to the above, if necessary, an appropriate amount of a crosslinking aid, an antioxidant, an inorganic filler, carbon black, a coloring agent, a lubricant, etc. may be added.

[0013]

In the past, metal oxides were mainly used as stabilizers such as hydrogen halides, but they are stabilized by capturing halogen ions and forming halides. It is considered that since the substance is too reactive, it actively takes in the halogen in the polymer, and as a result, the radicals and free ions increase, and eventually the deterioration is promoted. However, the hydrotalcite used in the first and second inventions does not have such a case, and since it effectively captures halogen, it exhibits stable efficacy over a long period of time and can improve heat resistance. it can.

Further, in a system using a halogen-based flame retardant,
Zinc oxide such as zinc oxide and magnesium oxide and lead-based compounds such as tribasic lead sulfate were often used alone, but as in the third and fourth inventions, metal oxides were used together. When these are added in a predetermined ratio, an excellent synergistic effect is exhibited. That is, initially, magnesium oxide positively captures and stabilizes the halogen, but since the reactivity is too strong, the halogen is taken in more than necessary, and as a result, radicals are increased. The zinc oxide effectively traps the radicals and the like to prevent deterioration, and the balance between the two affects heat resistance.

Therefore, according to the present invention, it is possible to improve the heat resistance as well as the flame retardancy, and it becomes extremely effective especially at high temperatures.

[0016]

EXAMPLES Examples of the present invention will be described in detail below.

Examples 1 to 8 in Table 1 and Comparative Examples 1 to 2 in Table 2
Each component shown in 10 was kneaded with a 6-inch roll held at 100 to 200 ° C., and this was further preformed by a press at 120 ° C. for 1 minute, and steam crosslinking (12 kg / cm ²
X 3 minutes) to produce a sheet having a thickness of 1 mm. For the electric wire, use a compound prepared by kneading the above components with a Banbury mixer.
0.8mm thickness on a 1.8mmφ core wire with a 0mm extruder
And were crosslinked in the same manner as the above sheet.

A heat resistance evaluation test, a flame retardancy evaluation test, and a bloom evaluation test were performed using each of these samples. That is, the heat resistance evaluation test is performed by UL-Subjec.
The flame retardancy evaluation test was performed according to the vertical burning test with electric wires (VW-1) and JIS-D-1201 (oxygen index was also measured as a reference). still,
Assuming that an OI value of 28 or more is required as a standard for passing the vertical combustion test (VW-1), the heat resistance effect was investigated for a system satisfying this. In the Bloom evaluation test, a sample sealed with an aluminum foil in a constant temperature layer kept at 60 ° C. was placed for 1 week for evaluation.

[0019]

[Table 1]

[0020]

[Table 2]

As a result, as shown in Examples 1 to 4 in Table 1, hydrotalcite showed extremely good characteristics as compared with other commonly used metal oxides. On the other hand, as shown in Comparative Examples 1 to 5 in Table 2, if the ratio with the flame retardant was lower or higher than the above-mentioned amount, the heat resistance was lowered, and in particular, the amount was excessively increased. It was confirmed that if a bloom occurs. In addition, as shown in Examples 5 to 8, the combined use of zinc oxide and magnesium oxide significantly improved the heat resistance. On the other hand, Comparative Example 6
As shown in Nos. 10 to 10, when zinc oxide and magnesium oxide are used alone, and when the ratio exceeds a specified ratio, the heat resistance is lowered, and even when used in combination with other stabilizers, the effect is so great. Absent. It was also confirmed that bloom was generated when a large amount of flame retardant was added.

[0022]

In summary, according to the present invention, since it has sufficient flame retardancy and can improve heat resistance, it has an excellent effect that it becomes extremely effective especially at high temperatures.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01B 3/44 P 9059-5G

Claims (4)

[Claims] 1. A blend of 5-60 parts by weight of at least one flame retardant and 5-60 parts by weight of antimony trioxide with respect to 100 parts by weight of an ethylene-based copolymer of ethylene bis-tetrabromophthalimide and perchlorocyclopentadecane. 10 to the above flame retardant in the composition comprising
A flame-retardant resin composition comprising 50% by weight of hydrotalcite. 2. A flame-retardant insulated wire comprising a conductor coated with the flame-retardant resin composition according to claim 1. 3. 5 to 60 parts by weight of a flame retardant of at least one of ethylene bis.tetrabromophthalimide and perchlorocyclopentadecane, and 5 to 60 parts of antimony trioxide, based on 100 parts by weight of the ethylene copolymer.
A composition characterized by containing magnesium oxide and zinc oxide in a ratio of 1: 3 to 3: 1 in a composition containing 10 parts by weight of the composition and 10 to 50% by weight of the flame retardant. Flammable resin composition. 4. A flame-retardant insulated wire comprising a conductor coated with the flame-retardant resin composition according to claim 3.