JPH07330980A - Low-smoking flame-retardant resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition which can be made flame-retardant and low-smoking by using additives even in such a small amount as not to deteriorate the mechanical properties. CONSTITUTION:This resin composition comprises 100 pts.wt. at least one member selected from among an ethylene/alpha-olefin copolymer, an ethylene/alpha-olefin/diene copolymer and an ethylene/vinyl acetate copolymer, 50-300 pts.wt. hydrated metal oxide, 1-40 pts.wt. melamine compound, and 1-50 pts.wt. talc.

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 suitable for insulating materials such as electric devices, electric wires and cables, and more particularly to a resin composition which produces less harmful gas and emits less smoke.

[0002]

2. Description of the Related Art 1 of ethylene-α-olefin copolymer
Ethylene-propylene copolymers (hereinafter referred to as EPM) and ethylene-propylene-diene copolymers (hereinafter referred to as EPDM), which are the seeds, are excellent in heat resistance, weather resistance, and electrical characteristics, and thus have been conventionally used as electrical insulating materials. Widely used. Since these copolymers are originally flammable materials, a large amount of halogen-based flame retardants, hydrated metal compounds, red phosphorus, etc. are blended to achieve flame retardancy.

However, when a halogen-based flame retardant or red phosphorus is added, there is a fatal difficulty in that toxic gas and smoke are extremely generated during combustion. On the other hand, when a hydrated metal compound is used, a large amount of addition is essential to obtain sufficient flame retardancy, so addition of a large amount of this significantly reduces mechanical properties and also causes smoke generation. There is a problem that it cannot be suppressed sufficiently.

Conventionally, ferrocene compounds, molybdenum compounds, boron compounds, etc. are known as additives for suppressing smoke emission. However, these smoke emission suppressants cannot improve flame retardancy and thus flame retardancy and smoke generation. It is not possible to simultaneously obtain the effect of suppressing.

On the other hand, in addition to the above flame retardants, nitrogen-containing flame retardants are known. Examples of the nitrogen-containing flame retardant include melamine and melamine cyanurate, and a flame-retardant resin composition obtained by adding an inorganic flame retardant and melamine cyanurate to a polyolefin resin can be seen (JP-A-2-7).
564).

However, there has been no effective resin composition capable of simultaneously satisfying a high degree of flame retardancy and a sufficiently low smoke generation property without impairing mechanical properties.

[0007]

SUMMARY OF THE INVENTION Therefore, the problem to be solved by the present invention is to provide a low-smoke-resisting flame-retardant resin composition capable of simultaneously performing a flame-retardant property and a smoke-suppressing effect in a small amount which does not deteriorate mechanical properties. Is to be newly developed.

[0008]

[Means for Solving the Problems]
α-olefin copolymer, ethylene-α-olefin-
The problem can be solved by adding a specific amount of a hydrated metal oxide, a melamine compound and talc to a resin component composed of at least one of a diene copolymer and an ethylene-vinyl acetate copolymer.

According to the research conducted by the present inventor, when a melamine compound which has been conventionally used as a flame retardant for EVA and nylon is used in combination with a hydrated metal oxide and talc, a synergistic effect of these three factors is obtained. It was found that not only the flame retardancy is further improved by the effect, but also the smoke generation can be suppressed very effectively.

[0010]

The resin composition of the present invention basically comprises the following components.

(A) Resin component 100 (b) Hydrated metal oxide 50 to 300, preferably 80 to 2
00 parts by weight (c) Melamine compound 1 to 40, preferably 3 to 30 parts by weight (d) Talc 1 to 50, preferably 5 to 30 parts by weight

As the resin component, one or more of ethylene-α-olefin copolymer, ethylene-α-olefin-diene copolymer and EVA is used.
When A is used alone, one having a vinyl acetate content of 20% by weight or less is preferably used. However, EV
The vinyl acetate content is not particularly limited when A is used in combination with another copolymer.

Typical examples of the α-olefin of the ethylene-α-olefin copolymer and the ethylene-α-olefin-diene copolymer include ethylene, propylene and butene-1.

Examples of preferable copolymers include ethylene-propylene copolymers and ethylene-propylene-diene copolymers.

When used alone as EVA,
As already mentioned, the vinyl acetate content is preferably 20% by weight or less. When used in combination with other copolymers, the vinyl acetate content is not particularly limited, but is usually 5 to 80, preferably 10 to 60% by weight.

Representative examples of the melamine compound include melamine and melamine cyanurate. These melamine compounds are 1 to 4 as described above.
It is used in the range of 0 parts by weight, and when it does not reach 1 part by weight, sufficient flame retardant and smoke suppressing effects cannot be obtained. On the other hand, if it is more than 40 parts by weight, the mechanical properties will deteriorate.

As the hydrated metal oxide used in the present invention, any of various hydrated metal oxides conventionally used as flame retardants can be used, and a typical example thereof is hydroxide. Examples are magnesium and aluminum hydroxide. The amount of the hydrated metal oxide used is 50 to 300 parts by weight as described above. As will be shown in Examples below, it is used within the above range in order to obtain sufficient flame retardancy and mechanical properties.

In the present invention, it is essential to use the melamine compound, the hydrated metal oxide and the talc together, and the flame retardant and smoke suppressing effects are sufficiently exhibited only by the combination of these three. . Even if one of them is lacking, the smoke suppression effect and sufficient flame retardancy can hardly be expected. Further, even if the melamine compound is used in combination with a conventionally known flame retardant other than the hydrated metal oxide, such as a halogen flame retardant or red phosphorus, the smoke suppressing effect cannot be expected.

By using the hydrated metal oxide, the melamine compound and talc in combination, the amount of the hydrated metal oxide used can be greatly reduced, and the mechanical properties, which have been a problem in the past, are deteriorated. Can be prevented.

As the talc used in the present invention, known ones can be widely used, but among them, the average particle size is 0.1 to 5
Fine talc of about μm is preferable.

The resin composition of the present invention can be crosslinked if necessary. The cross-linking means at this time is not particularly limited, and various cross-linking means such as chemical cross-linking means, radiation cross-linking means, silane cross-linking means and the like can be exemplified, and a conventionally known method using a cross-linking agent and a cross-linking aid as necessary. Just crosslink with.

The composition of the present invention contains an antiaging agent, a silane-based or titanium-based coupling agent, a processing aid, a plasticizer, and various other known additives within a range that does not impair the object of the present invention. It can be added. Also molybdenum compounds,
A smoke inhibitor such as a boron compound and a flame retardant such as red phosphorus may be used in combination.

[0023]

The resin composition of the present invention is excellent in low smoke generation, flame retardancy and mechanical properties, and therefore, can be used in ships, vehicles, tunnels,
It is extremely effective as a coating composition for electric wires used in underground shopping malls.

[0024]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples.

[0025]

Examples 1 to 9 Predetermined components shown in Table 1 below were adjusted with a roll mill, molded by hot pressing at 170 ° C. for 20 minutes and crosslinked to prepare crosslinked sheets for each composition. Various properties were measured for these various sheets. The results are shown in Table 2.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Comparative Examples 1 to 6] Crosslinked sheets of various resin compositions were prepared in the same manner as in Examples using the predetermined components shown in Table 3 below. For these, various characteristics were measured as in the examples. The results are shown in Table 4.

[0029]

[Table 3]

[0030]

[Table 4]

However, the components of Tables 1 and 3 are as follows, and the various measuring methods of Tables 2 and 4 are also as follows.

EPDM-1: EP-51 (manufactured by Japan Synthetic Rubber Co., Ltd.) EPDM-2: EP-21 (manufactured by Japan Synthetic Rubber Co., Ltd.) EVA-1: Levaprene 450 (manufactured by Bayer Co., vinyl acetate content 45% by weight) EVA -2: EvaTate H2020 (Sumitomo Chemical Co., Ltd., vinyl acetate content 15% by weight)

ZnO: No. 3 zinc white Stearic acid: ADEKA fatty acid SA-200 (manufactured by Asahi Denka Kogyo Co., Ltd.) Antiaging agent-1: Nocrac MB (Ouchi Shinko Chemical Co., Ltd., benzimidazole type) Antiaging agent-2 : Vulkanox DDA (manufactured by Bayer, diphenylamine type) Process oil: Sansen 4240 (manufactured by Nippon San Oil Co., Ltd.) Mg (OH) ₂ : Kisma-5B (manufactured by Kyowa Chemical Industry Co., Ltd.) Al (OH) ₃ : Hydilite H43M (Showa era) Fine metal talc: Mistron vapor (Misstron Japan, average particle size 2.3 μm)

Clay: Saranton W / Whitetex (manufactured by Engelhard) Carbon: Diamond Black H (manufactured by Mitsubishi Kasei) Red phosphorus: Novaret 120UF (manufactured by Rin Kagaku) Melamine cyanurate-1: MC690 (Nissan Chemical Co., Ltd.) Melamine cyanurate-2: HC610 (manufactured by Nissan Chemical Industries, Ltd.) Crosslinking agent: DCP (manufactured by Mitsui Petrochemical Industries, Ltd.)

Measurement method LOI: Measured according to JIS K 7201. Smoke generation amount: The maximum value (Dm) of smoke density was measured according to ASTM E662. Tensile strength: Measured according to JIS K6301. Elongation: Measured according to JIS K6301. Volume resistivity: Measured according to JIS C 2123.

Claims (5)

[Claims] 1. An ethylene-α-olefin copolymer, an ethylene-α-olefin-diene copolymer and ethylene-
100 parts by weight of at least one vinyl acetate copolymer, 50 to 300 parts by weight of hydrated metal oxide, 1 to melamine compound
A low smoke-producing flame-retardant resin composition containing 40 parts by weight and 1 to 50 parts by weight of talc. 2. An ethylene-α-olefin copolymer and /
Alternatively, the ethylene-α-olefin-diene copolymer is 95
To 5 parts by weight, and ethylene-vinyl acetate copolymer 5 to 9
50 to 300 parts by weight of hydrated metal oxide and 1 to 4 of melamine compound per 100 parts by weight of resin component consisting of 5 parts by weight.
The low smoke generating flame-retardant resin composition according to claim 1, wherein 0 part by weight and 1 to 50 parts by weight of talc are contained. 3. 50 to 300 parts by weight of a hydrated metal oxide, 1 to 40 parts by weight of a melamine compound, and 1 to 50 parts of talc with respect to 100 parts by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 20% by weight or less. A low-smoke-retardant flame-retardant resin composition containing parts by weight. 4. The flame-retardant resin composition having low smoke emission according to claim 1, wherein the composition is crosslinked. 5. The flame-retardant resin composition having low smoke emission according to any one of claims 1 to 4, wherein the melamine compound is melamine cyanurate.