JPS61243606A - Flame resisting electric insulation composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a flame-retardant electrical insulation composition that does not generate harmful halogen gases when burned, and is particularly suitable for application to insulation of electric wires and cables. This invention relates to a flame-retardant resin composition.

[Prior Art] Polyolefins, which have excellent electrical insulation properties, have been widely used as insulation materials and sheath materials for electric wires and cables.

Due to recent trends, UL standards VW-
There has been a strong demand for the flame retardant properties of Rubel.

As a method of making polyolefin flame retardant, a method of mixing a halogen-containing compound, a phosphorus-containing compound, etc. is generally adopted.

However, these produce a large amount of smoke when burned, causing problems such as corrosivity to equipment and toxicity to the human body. In particular, recently there has been a strong demand for safety to prevent the generation of such halogen gases.

In light of this situation, inorganic flame retardants with very low smoke generation and toxicity have started to attract attention. Among them, in order to impart flammability, water of crystallization must be released near the decomposition temperature of Lima, and hydroxide magnetic screw with high absorption capacity must be used.
Kumu is particularly effective.

``Problems that the invention attempts to solve'' However, it imparts combustibility at high altitudes.
□It is necessary to add a large amount of magnesium oxide,
As a result, there is a problem in that the mechanical properties of the resulting insulator are deteriorated.

The present invention has been made based on the above, and provides a flame-retardant electrical insulating composition that can impart a high degree of flame retardancy, has excellent mechanical properties, and does not generate toxic halogen gases. The purpose is to

[Means for solving the problems] The flame-retardant electrical insulation composition of the present invention comprises (a) a polyolefin, (b) magnesium hydroxide, and (c) a low-temperature decomposable inorganic hydrate. The total amount of component ([)) and component (c) is 100 to 3 parts by weight per 100 parts by weight of component (a).
00 parts by weight, and the blending ratio of component (b)/component (c) is 9515 to 60/40.

In the present invention, the polyolefin of component (a) includes ethylene propylene copolymer, ethylene propylene diene turbo polymer, polyethylene, ethylene vinyl acetate]
Polymers such as (1) ethylene ethyl acrylate 1-] polymer, (2) dilene butene copolymer, and ethylene butene dicarbonate polymer can be used alone or in combination of two or more.

Component (h), magnesium hydroxide, can be used as is, but in order to improve compatibility with polyolefins, it may be surface-treated with fatty acids, fatty acid metal salts, aliphatic alcohols, aliphatic esters, etc. It is preferable to use

The low-temperature decomposition type inorganic hydrate of component (c) refers to an inorganic hydrate that decomposes at a temperature lower than 350°C of decomposition temperature of magnesium hydroxide. , barium metaborate hydrate, and calcium sulfate hydrate.

By using low-temperature decomposition type inorganic hydrate in combination with magnesium hydroxide, it exhibits a flame retardant effect over a wide temperature range. deterioration of physical properties can be suppressed.

The total amount of components (b) and (c) must be in the range of 100 to 300 parts by weight per 100 parts by weight of component (a). If it is less than 1'00 parts by weight, the desired flame retardancy cannot be imparted, and if it exceeds 300 parts by weight, the tensile properties will be significantly reduced.

In addition, the content ratio of component (b)/component (c) is 9515
It is necessary to set it in the range of ~60/40. If the proportion of component (b) is more than 95% by weight or less than 60% by weight, the flammability or tensile properties will be significantly reduced.

In the present invention, in addition to the above components, crosslinking agents, antioxidants, lubricants, softeners, dispersants, etc. may be added as appropriate.

As a crosslinking agent, dicumyl peroxide, 3-bis(
An organic peroxide represented by t-butylperoxyisopropylbenzene is suitable, and this can be used in combination with sulfur, ethylene dimethacrylate, diacrylphthalate, p-quinone dioxime, etc. as a crosslinking agent. Good too.

As an antioxidant. phenyl-α-naphthylamine,
Amine antioxidants such as N,N'-di-β-naphthyl-p-phenylenediamine, 2,6-di-1-butyl-4
- Phenolic antioxidants such as methylphenol and hindered phenol.

[Example 1 Various ingredients were heated at 100°C according to the blending ratios shown in Table 1.
A 40 m/m extrusion 1 (held at 120°C) was put into a 6-inch 1
L/D=25), with a thickness of 1 on a copper wire with an outer diameter of 2.0 m.
．． Extrusion coating on 0 layers followed by 13k! +/Cll12
A crosslinked insulated wire was prepared by holding the wire in a water vapor atmosphere for 3 minutes.

The evaluation results for each individual are shown in the lower column of Table 1.

The evaluation was carried out using the following method.

Flame retardant: LJ if extinguished within 1 minute by combustion with a burner
It passes L standard VW-1, but it fails if it burns for more than 1 minute or burns out completely.

Tensile properties: After cross-linking, the conductor was pulled out and placed in a constant temperature room at 20℃ for 1
After being left in the sun, it was measured using a Schottspa type tensile tester at a tensile speed of 500 mm/min.

As is clear from Table 1, Examples 1 to 1 according to the present invention
In No. 6, all of them passed the UL and standard VW-1 flammability tests, and the tensile strength also satisfied the electrical appliance standards for ethylene propylene rubber.

On the other hand, Comparative Example 1, in which the content of magnesium hydroxide and low-temperature decomposable inorganic hydrate was below the specified value, failed in flame retardancy, and Comparative Example 2, in which the content was above the specified value, was poor in tensile properties.

In Comparative Examples 3 and 4, the ratio of the amount of magnesium hydroxide blended was outside the specified value, and the flame retardance was insufficient.

[Effects of the Invention] As explained above, the present invention uses magnesium hydroxide and a low-temperature decomposition type inorganic hydrate (71) as a flame retardant, and has a high degree of flame retardancy while maintaining good tensile properties. It becomes possible to obtain a molded product that can give (1) and does not emit toxic halogen gas when burned.

Claims (1)

[Claims] (1) Contains (a) polyolefin, (b) magnesium hydroxide, and (c) low-temperature decomposition type inorganic hydrate;
Component (b) and (c) are contained in a total of 100 to 300 parts by weight per 100 parts by weight of component (b).
) component/(c) component blending ratio is 95/5 to 60/40
A flame-retardant electrical insulation composition.